environmental science & technology 1979 vol.13 no.3

For Thermally-Unstable GasesThe RAC Model PV Sequential Sampler meets orexceeds EPA specifications for gas samplers ofits type. For sampling S02 and other thermallyunstable gases, this instrument is equipped witha unique solid-state thermoelectric coolingheating system that maintains the gascollecting reagent for S02 at 12°C (53.6°F) toassure maximum sample stability. Collectedsamples of S02 begin to dissipate when temperatures reach 20°C (68°F), and about 75% of acollected/stored sample will be lost within 24hours at an ambient temperature of 50°C (122°F).

The RAC Model PV/TE Sequential Samplereliminates this type of degradation and theresulting loss of sampling accuracy.

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Volume 13, Number 3, March 1979 253

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254 Environmental Science & Technology

CONTENTSVolume 13, umber 3, March 1979

OUTLOOK

266Visibility. The 1977 clean air amendments made it a national goal and EPAis charged with proposing a regulationlater this year

269Solar energy. Honeywell is using it toheat and cool its General Offices inMinneapolis

271Water technology. Membrane systemof Innova, Inc. is readied for removingions of your choice from industrialwastewaters

272Engineering. The firm of MichaelBaker Corp. found existing air andwater control to be adequate for acopper producer in Michigan

274Analysis of pollutants. A 9th annualsymposium in Georgia this May hasplenary lectures on the Toxic Substances Control Act

REGULATORY ALERT

277The bubble concept. ERT's Delandexplains its application in air, but notfor water. and its future

FEATURES

278Carcinogenic products in nature:Not all cancer-causing substances areman-made-E. K. Weisburger, ational Cancer Institute

year. Air freight rate~ per year a~ailablc on request. Singlecopio: current i~,uc.'. 55.00. Rates for back issuo and \'olumesarc :I\'ailablc from Spl.'Cial Issues Sales Depannlent. 11)5 16thSI., N.W.. Washington. D.C. 20036. Claims for missingnumocrs..... ill nOI be allowed if los.~ ..... alo duc to failure of notice of changeof address to lx' rcccivcd in the time specified: ifclaim is dated(a) North America: more lhan 90 days bl::yond issue date, (bl:llt other foreign: more than onc year beyond issue d:lte: or if therealoOn gi~en is "mi~ing from fites:' 1·lard copy claims arehandled at thc ACS Columbus address.

SlJBSCRIPTION SERVICE: Send all ne ..... and renewalsubscription:- with payment to: Ofriee of the Controller. 1155161h 51.. N.W,. Washington. D.C. 2003fl. All correspondenceand telephone call:- regarding changelo of address. claims formissing issues. subscription ser~icc, Ihe status of records andaCl:ounh. air mail and air freight ratcs should be directed to:Manager. Membership and Subscription Services. AmericanChemical Society. P.O. Box 3337. Columbus. Ohio 43210.Te1crhonc (614) 411· 7230. On changes of addres.... ind,,!de both

282Trace elements: Recent developmentsin the bio- and environmental chemistry of some candidates-R. A. Zingaro, Texas A&M University

288Sampling and analysis: Syntheticfuel processes present uniquechallenges-Po S. Dzierienga, F. G.Mesich, and R. A. Magee, RadianCorp.

RESEARCH295Determination of heavy-metal distribution in marine sediments. Edwin S.Pilkington and Leonard J. Warren*

Atomic absorption spectrometrywas used to analyze for the low levelsor lead, cadmium, and zinc in thedensity subrractions or near-shoremarine sediments.

299Coagulation and direct filtration ofhumic substances with polyethylenimine. Harold T. Glaser and James K.Edzwald*

The results or studies on the removalor humic substances (pH 5.5-6) withpolyethylenimine polymers (mol wt600-100000) are reported.

305Competitive adsorption of 2,4-dichlorophenol and 2,4,6-trichlorophenol inthe nanomolar to micromolar concentration range. Carol J. Murin andVernon L. Snoeyink*

Strong competition was observedbetween the anionic and neutral chlorophenol species ror adsorption byactivated carbon. The presence orhumic substances also decreased thecapacity or the carbon for chlorophenols.

old and new addresses with ZIP code accompanied by a rC1:entmailing label. Allow six weeks for change 10 become effective.

f\.-lICROFIU\1 OR MICROFICHE. For information. wrileto: Microform Program. ACS. 1155 16th St .. N.W.. Washington. D.C. 200J6. or call (202) 872-4554.

The American Chemical Society assumes no rcsponsibililYfor thc statements and opinions advanced by contribulors to thepublications. Views expressed in Ihe editorials :lrc those of theauthor and do not neccs.'~arily represent the ofricial position ofthc Society.

CrcdilS: 261, 1::S&Ts Julian Josephson: 264, RaderCompanies. Inc,. and The Standard Oil Co. (Ohio);271, 1::S& Ts Julian Josephson

('o,'cr: Steve Ember

311Growth and element uptake of woodyplants on fly ash. David H. Scanlon*and J. Carroll Duggan

Woody plants grown on coal ashshowed an increased foliar concentration of B, Ni, and Se. Uptake of Hgand As varied by species, while Cr andPb showed no increase over soil-grownplants.

315Impingement sampling frequency. Amultiple population approach. FaroukM. EI-Shamy

Two years of impingement datawere analyzed to design a samplingprogram based on the optimum allocation method. Intensive samplingduring months of peak fish abundancegave a more precise estimate of yearlyimpingement than sampling evenlythroughout the year.

321Reaction of sulfur oxides with aluminaand platinum/alumina. Jack C. Summers

SOx reactions with AI20 J andPt/AI 20 J were studied to elucidate theproblems of S02 adsorption in thecatalytic converter.

325Chloroform and chlorophenol production by decarboxylation of naturalacids during aqueous chlorination.Richard A. Larson* and Arlene L.Rockwell

Naturally occurring carboxylicacids reacted in dilute solution withaqueous hypochlorite to form decarboxylation products, incorporating thechlorine into the residual organicmolecule.

329Determination of several industrialaromatic amines in fish. Gregory W.Diachenko

A procedure is described for thedetermination of selected aromaticamines in fish, using nitrogen-selectivegas-liquid chromatography.

t:ditor: Russell F. ChristmanAs.wciale Editor: Charles R. O'MeliaWASHINGTON EIJITORIAL STAFfManaging Editor: Stanton S. MillerAnociale Editor: Julian JosephsonAssociate t:ditor: Lois R. EmberMANUSCRIPT REVIEWINGManager: Katherine I. BiggsA.ui.Haflf Editor: Sheila M. Kennedyt:ditor;1I1 A.\'s;.t!ant: Rosalind M, BishMANUSCRIPT [BITINGAssociate Editor: Gloria L. DinoteAs.wl'iate Editor: Deborah /\, WilsonGRAPHICS AND PRODUCfIONProduction Manager: Leroy L. CorcoranDesigner: /\Ian Kahan Arti.t!: Linda M, Mattingly

333Determination of air-water Henry'slaw constants for hydrophobic pollutants. Donald Mackay*, Wan YingShiu, and Russell P. Sutherland

A novel system is described for thedetermination of Henry's law constants for hydrophobic compoundsbetween air and water with an accuracy of about 5%.

338Lead concentrations: Bats vs. terrestrial small mammals collected near amajor highway. Donald R. Clark, Jr.

Lead concentrations in little and bigbrown bats are compared with those inmeadow voles, white-footed mice, andshort-tailed shrews.

341Analysis of adsorption properties andadsorbed species on commercial polymeric carbons. William L. Fitch andDennis H. Smith*

A new, simple method for measuring the adsorptivity of polymeric carbons, using tritium-labeled benzo[a]pyrene, lias been developed and used tocompare 12 commercial polymericcarbons.

NOTES

346Microbial release of oil from soil columns. Rudi Vanloocke, Anne-MarieVerlinde, Willy Verstraete, and Raymond De Borger*

Laboratory studies indicate that byirrigating oil-polluted soil with a nutrient solution containing ammoniumnitrate and peptone, 10-20% of the oiladsorbed in the soil can be recovered ina period of 3-4 months.

Advisory Board: Robert J. Charlson. Charles Coutant.Rudolf"B, Husar. Roger A. Minear. Francois M. M.Morel. Frank P. Sebastian. R. Rhodes Trussell. CharlesS. Tuesday. William E. Wilson. Jr.

Published by theAMERICAN CHEMICAL SOCIETY1155 16th Slree.. N.W.Washington. D.C. 20036(202) 872-4600

BOOKS AND JOURNALS DIVISIOND. H. Michael Bowen. DireclOrCharles R. Bertsch. Head. Journals Depanml'tlfBacil Guiley. Head, Magazifll' and Production

Department

'"·~Hl·3'oUI~ mjJ·H18·1i'\1~ln "" i. q,.. :; ~r.25?2

ESTHAG 13(3) 253-374 (1979)ISSN 0013-936X

349Laser-induced fluorescence and Ramanscattering for real time measurement ofsuspended particulate maUer. I. Allegrini* and N. Omenetto .

Observations of induced inelasticscattering of artificially generatedaerosols indicate that fluorescencearising from most aerosols can degradethe signal-to-noise ratio to unpracticalvalues when measuring Raman signals.

351Pressure change effects on hypodermicneedle critical orifice air flow rates.Paul Urone* and Richard C. Ross

A study of the effect of ambient airpressure changes on critical flow ratesshowed that comparative theoreticalpressure change calculations gave excessively low flow rates for largepressure changes.

CORRESPONDENCE

354Venturi scrubber performance model.William Licht. Seymour Calvert

* To whom correspondence should be addressed.

This issue contains no papers for which there is supplementary material in microform.

DEPARTMENTS

257 Editorial258 Letters261 Currents355 Industry trends357 Products361 Literature364 Books367 Meetings368 Classified section371 Consulting services

Seldon W. Terrant. Head, Rl'search andDevelopment Depanmell1

Marion Gurrcin. Circulation Devt'lopmetlf

ADV£RTlSINC; MANAGEMENTCcntcom. Ltd.For orriccrs and advertisers. see page 372

Please send re.H'arch manuscripts to ManuscriptReviewing.fellfure manuscripts lo ManagingEditor.

For author's guide and editorial policy. see January1979 issue. page,) I. Ilr write Katherine I. Bi!!gs.Manuscript Reviewing Office FS(f; T. /\ salllplecopyright transfer form. whidl may be copied.appears 011 p;lge 110 of the January 1979 issue.

Volume 13. Number 3, March 1979 255

GUEST EDITORIAL

Controlling toxic substances:setting research priorities

In the early 1950's, it was discovered that hydrocarbons and nitrogen oxides react in the atmospherein the presence of sunlight to form ncw, morc noxioussubstances-photochemical smog. Identification ofthe sources of the smog precursors. largely automobileemissions and power-plant stack gases, led to government regulation of two major industries-automobile manufacturing and electric power generation.The technological and economic consequences havebeen profound.

Now we arc moving toward the regulation of another major industry; the chemical industry manuractures substances used in products ranging fromsynthetic fibers and pesticides to membranes for artificiallungs and kidneys. Industry sales exceed $100billion per year with over 30000 chemicals on themarket and perhaps a thousand new ones introducedeach year.

Inevitably, given the size and complexity of theindustry, chemicals have escaped to the environmentthrough air and water routes and caused harmful efrects on human health or the ecology. Scientifically.the problem is in some ways much more complex thanthose which have been handled in the past.

One of the main problems is the variability in thenature of emissions from the chemical industry because the sources arc of so many different types.Typical chemical industry emissions arc not as welldefined as, say, automobile exhaust or stack gasesrrom coal-fired power plants. This complicates effortsto define surrogates or indicators for classes of toxicsubstances. Another difficulty is that the concentrations of the chemical species of concern arc often verylow and hard to detect with available instrumentation.

Finally the time scale over which biological andecological effects arc produced may be long, comparedwith the time scale for conventional pollutants. Although control of these substances is ~ssential,

heavy-handed regulation would be a mistake. Redtape and loss of propri'ctary position will discourage

innovation by industry. The result will be the loss tosoeiety of useful new products and proeesses.

Government and industry arc now grappling withthe development of procedures for dealing with theseproblems. This is a critical time because precedentsare being set. One might say, "Identify all potentiallytoxic substances present in industrial emissions andreljuire that industry remove them. Do the same fornew technologies before they go into production."Indeed, both industry and the EPA arc relying heavilyon toxicological studies and other biological tests forscreening the many chemical compounds involved.

It would bc a mistake to make this the main focusof the toxic substances control program. In manycases, neither the level of human exposure, nor therelative importance of the sources is known. For example, urban and industrial regions such as NewJersey and the Houston area contain many differentsources '01' chemical emissions. Methods have beendeveloped for the resolution of complex air quality /emission source relationships for certain classes ofpollutants. High priority should be given to extendingthese methods to potentially toxic organic chemicals.

The results of such studies should be used in settingpriorities for emission coritrol based on source contributions to human exposure. They should also provide guidance for biological screening tests at concentrations corresponding to realistic evaluations ofhuman exposure. Let's put numbers on human exposure and source contributions.

S,;(,q~

Dr. S. K. Friedlander is Professor of En·gineering and Applied Science and Vice·Chairman. Chemical Engineering at theUniversity ofCalifornia. Los Angeles.


LETTERS

Mirex-final word

Dear Sir: Peakall and coworkers arecorrect to point out some typographical errors and misleading captions tosome paragraphs in the feature article,"The rise and fall of Mirex" (Ref.letter, ES& T. December 1978, p1348). Regrettably, the extremelyshort turnover between acceptance andtypesetting of the manuscript, togetherwith some last minute changes andproofreading led to such error.

I do reject, however, Peakall'ssweeping assertion that my report " ...suffers from the lack of a proper biological insight." For a number of years,I have been involved with the implicatIOns of biological effects of contaminants on water quality objectives.Further, the manuscript had also beenreviewed by biologists prior to itspu bl ica t ion.K. L. E. KaiserNational Water Rcsearch InslitutcBurlington, Ontario,L7R 4A6 Canada

Correction

• December 1978, p 1352. The limedemand by 1990 is incorrectly reportedin pounds. The correct lime demand by1990 is 10 million tons.

Hazardous Materials ResponseProject, National Oceanographic andAtmospheric Administration, Environmental Research Laboratories,Boulder, Colo. 80302, where the scientist's interest lies seaward of theterritorial baseline. As scientific support coordinator for Federal Region II,I would be pleased to hear from thosescientists whose interest lies landwardof the territorial baseline of New YorkNew Jersey, Puerto Rico, and the U.S:Virgin Islands.

We wish to identify members of thescientific community who should becontacted during a particular spill andthereby improve scientific input andcoordination in such events.Fred N. RubelU.S. EPARegion IIEdison, N.J. 08817

Toxic substances testing-correction

Dear Sir: There is a significantmisprint in the table of compoundsrecommended for priority testing bythe Interagency Toxic SubstancesTesting Committee (fTC). Alkylphthalates are shown in that table(ES&T. November 1978, p 1246) asbeing recommended for "other toxiceffects" testing. This is erroneous. TheITC recommended only "environmental effects" testing for phthalates.It should be noted that alkyl phthalateesters arc among the least toxic substances known, and an error such asthe one cited above might lead to aninappropriate conclusion to the contrary. It is, in fact, their general loworder of toxicity and consequent widecommercial use that have promptedtheir being recommended for environmental testing. Alkyl phthalatesare a very important family of commercial compounds and only one kindof testing-environmental-has beenrecommended.J. W. HirzyMonsanto Industrial Chcmicals Co.St. Louis. Mo. 63166

Wanted: oil spill scientists

Dear Sir: In the wake of spills ofhuge amounts of oil from the ARGOMERCHANT and the AMOCOCADIZ, efforts are underway by theFederal government to improve coordination of scientists involved in research or damage assessment, and toimprove methods whereby scientistscan provide support to the on-scenecoordinator for a spill cleanup.

Assistance is needed in contactingscientists which may respond in connection with existing research projects(not a solicitation for new researchgrants) during potentially criticalchemical or oil spills in the waters ofthe U.S. Details regarding their scientific interest and capability can beforwarded to Dr. Paul Lefcourt, U.S.EPA (RD-683), 401 M St., S.W.,Washington, D.C. 20460, where thescientist's interest lies landward of theterritorial baseline anywhere in theU.S., or to John Robinson, Manager,

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INTERNATIONAL

"Ultimately, we hope to replace oiland nuclear energy with renewableenergy sources," Ola Ullsten,prime minister of Sweden, toldES&T. Meanwhile, he noted thatSweden will build 11-12 nuclearplants-6 are now in operationand send spent fuel to France forreprocessing. Ullsten said that hiscountry has a new, "sophisticated"method devised to bury nuclearwastes in Swedish rock. Aside from

Swedish prime minister VIIs/en

those plants and procedures, heforesaw no further nuclear efforts in Sweden. Also, Ullsten described a "tragic lack of concern"with acid rain, on an internationallevel, and called for sharply increased environmental consciousness with respect to Third Worlddevelopment.

WASHINGTON

EPA proposed premanufacturenotification rules under the ToxicSubstances Control Act. These regulations were proposed under section 5 of the act, which requiresmanufacturers of chemicals to notify EPA Of their intention to manufacture a substance at least 90 daysbefore full-scale commercial production begins. The manufacturerwill be required to submit all available information on how the uses ofthe new chemical will affect humanhealth and the environment. EPAwill evaluate the submitted information, weigh the benefits againstthe risks, if any, and take necessaryprecautionary steps to reduce therisks. The steps may range frommerely requiring precautionary la-

CURRENTS

beling to a total ban on the use ofthe substance.

CEQ's Ninth Annual Report finds ageneral improvement in air qualityin the 16' major cities studied.There was an 8% decrease in thenumber of days with unhealthy airquality from 1973-1976. Of thefive major criteria air pollutants,only nitrogen dioxide showed notrend of improvement. Also, while94% of all major sources were incompliance with the air standards,there are still major examples ofnoncompliance, principally in theiron and steel industry, metalsmelters and large coal- and oilfired power plants. With expandedclean-up efforts, aquatic life has recovered and water quality has visibly improved in many bodies; however, the uniform national monitoring system (NASQAN) has onlybeen in operation for three years,and covers only some water pollutants, so trends are difficult to discern. CEQ estimates that the U.S.is still spending only 2% of theGNP on pollution control efforts.

President Jimmy Carter

EPA's fiscal 1980 budget, as proposed by President Jimmy Carter,is $5.1 billion, of which $3.8 billionis slated for constructing sewagetreatment plants and $1.3 billion isslotted for the agency's operatingprogram. EPA's permanent workforce will expand to 10945, up by247 people. The new budget emphasizes the control of toxic chemicals, expanded health-effects studies, enforcement of pollution-controllaws, strengthening of state environmental programs, and the improvement of EPA's management

and regulatory reform efforts. Thelargest increases are for programsto test toxic chemicals; and forgrants to states for air pollutioncontrol and drinking water improvement, as well as hazardouswastes control.

An EPA- and CEQ-sponsored studyfinds that pollution control programs create jobs and cause littleinflation. The study, "The Macroeconomic Impact of Federal Pollution Control Programs: 1978 Assessment," by Data Resources, Inc.(Cambridge, Mass.), states that airand water pollution clean-up programs will add no more than 0.10.2% to the average annual inflation rate over the next eight years,and that unemployment will dropby an average of 0.2-0.3% duringthe same period because of the federal pollution control programs.The study does not consider thehealth and other benefits that result from pollution control. Copiesof the report may be obtained fromthe Council on EnvironmentalQuality, Washington, D.C. 20006.

The Interior Department andNOAA oppose construction of theHampton Roads oil refinery atPortsmouth, Va., and the InteriorDepartment has asked the ArmyCorps of Engineers to deny theHampton Roads Energy Companya construction permit. The EPAand Interior had previously opposed the oil refinery at this site,but in November, the Corps recommended that a construction permitbe granted. NOAA, in its letter tothe Chief of Engineers said that arefinery at this site "poses a gravethreat to the Chesapeake Bay's $87million shellfish industry andtherefore should not be approved." ,Interior objects to this site for thesame reasons as NOAA. Ultimateauthority for permit issuance restswith Army Secretary Clifford W.Alexander, J r.

EPA announced a new standard forozone, which it set at 0.12 ppm.Originally the standard was set at


0.08 ppm for photochemical oxidants. The name of the pollutantwas changed to ozone to reflect thefact that it is the most abundantphotochemical oxidant. EPAclaims that the new standard "provides an appropriate margin ofsafety for asthmatics, babies, theelderly and other sensitive individuals." Compliance will be determined by the number of days peryear which have hourly ozone averages exceeding the 0.12 ppm standard; an area will be in noncompliance with the standard if it exceeds the limit more than one day.

STATES

Block Island, R.I., may return tothe use of peat to fuel its generators. The island, 12 mi off theRhode Island coast, contains bogswith peat of high enough quality tobe used as fuel. But many questionsremain unanswered. The RhodeIsland Energy Office, therefore,applied for and obtained a $10000federal grant to study the feasibility of harvesting the peat for use ingenerators. If it proves feasible, thepeat will replace diesel oil whichnow fuels the generators. The 500permanent residents of the islandpay the highest electricity bills inthe state, primarily because thediesel oil must be shipped in fromthe mainland.

How can California ensure enforcement of strict air quality standardsand provision for new powerplants? Through better coordination say Energy Commission chairman Richard Maullin and Air Resources Board chairman TomQuinn. At the announcement of aproposed joint policy, Maullin andQuinn said that local air qualitydistricts will playa larger role inthe power plant approval process.Newly built electric utilities wouldstill be required to use "the mostadvanced air pollution controls ontheir new plants." At press time,the joint policy had not been formally approved by the agencies.

Under a consent decree, Pennsyhania will begin inspection/maintenance programs in Philadelphiaand Pittsburgh. Under the program, all automobiles and lightduty trucks will be tested annuallyfor polluting emissions. Vehiclesfailing to meet state emission standards must make corrective repairs. According to U.S. EPA estimates, this program will reduce


carbon monoxide and hydrocarbonemissions in Philadelphia and Pittsburgh about 25% by March 1987.The program is funded in part by a$400000 EPA grant. The I/Mprogram can be conducted by a single private franchiser or by theCommonwealth. Similar I/M efforts are in effect in Rhode Island;Cincinnati, Ohio; Las Vegas andReno, Nev.; Phoenix and Tucson,Ariz.; and Portland, Ore.

Sayre views carbon fill

The Appomattox River Water Authority of Petersburg, Va., will usegranular activated carbon to curbtaste and odor problems. Generalmanager Robert E. Sayre announced the signing of a three-year"Potable Water Service" contractwith Calgon Corp. (Pittsburgh,Pa.). Under the contract, Calgonwill supply 198 000 Ib of granularactivated carbon to correct tasteand odor problems at the authority's 22-million gallon/day plant located at the Lake Chesdin damnear Matoaca.

The mandatory beverage containerdeposit ordinance failed in FairfaxCounty, Va., claims the GlassPackaging Institute and the CanManufacturers Institute, the sponsors of a recent study. The ordinance, the study found, is drivingcustomers out of the county, causing a change in drinking habits andlosing the county tax revenues. Thestudy was conducted by a GeorgeMason University professor, R. L.Entrikin, who found that soft drinksales plummeted 11.7% since thefive-cent bottle deposit law wentinto effect in late 1977; sales outside the county rose by 16-19%.The loss to county business was estimated at $14.6 million, and taxrevenue losses were estimated at$34000. The deposit law was notadopted by other jurisdictions inthe Washington metropolitan area.

Clean up of the waterways in theChicago, III., metropolitan area willcost $7.5 billion. A costly plan wasadopted recently by the Northeast-

ern Illinois Planning Commission;it involves more than 300 units oflocal government in the metropolitan area. About 96% of the multibillion dollar plan are costs forwastewater treatment projects, butthe plan also calls for an end to polluted overflows from combinedstorm and sanitary sewers and a reduction in pollution from urbanstorm water runoff.

In an out-of-court agreement, aMinnesota company bas agreed toclean up its air and water poUution,and pay up to $45 000 in penaltiesfor past violations. The AmericanCrystal Sugar Co., in a plan approved by the Minnesota PollutionControl Agency, has agreed to undertake extensive pollution controlmeasures at its East Grand Forkssugar beet processing plant.

MONITORING

Measurement of sulfuric acid influe gases is the object of a designand development contract awardedby EPA (Research Triangle Park,N.C.) to Laser Analytics, Inc.(Lexington, Mass.). The principlewill be to pass active light throughthe gas, and determine sulfuric acidvapor by ascertaining the amountof light absorbed. EPA engineerRoosevelt Rollins noted that mostpollutant gases absorb infrared radiation in differing amounts, and atdifferent positions in the infraredspectrum. He said that improvedsulfuric acid measurement will bebrought about by using a tunablediode laser (infrared) as a lightsource.

TECHNOLOGY

Glassing in radioactive waste, andburying it in salt may not work, according to new findings by scientists in the U.S., Australia, andSweden. Recent tests have shownthat with heats associated with radioactivity, the glass could start tomelt, and the "hot" materialswould leak. Worse, when the containers were put in salt, and watersomehow got in, hot brines couldetch the glass, and leach out materials such as strontium and cesiumin one week. Etching occurred evenwith obsidian, an extremely stablenatural glass. On the other hand, a"Synrock" synthetic mineral material could work much better, according to scientists at The Pennsylvania State University.

How to get the devil out of yourwaste stream and the EPA off your back.Organic contamination of plant waste streams is adevil of a problem Contaminants such as phenol.dyestuffs, chlorinated pesticides, and chlorinated hydrocarbons, to name a few, give the modernindustrial producer a myriad of troubles.

How can one remove these chemicals from wastestreams? Is the method used satisfactory? What do Ido with recovered chemicals? Will the removal process meet federal and local standards? Is therecovery or removal process economical?Through constant research and developmentoverthepast four decades, Rohm and Haas Company has

pioneered the technology that can give you the rightanswers. Our line of Amberlite'" polymeric adsorbentsand ion exchange resins provides industry with products that will safely and economically adsorb theseand other chemicals from plant waste streams.

We will be pleased to discuss your organic wasteproblems and possible solutions. For further information, circle our reader servicenumber or contact Rohm and RDHM~Haas Company, Marketing Ser-vices, Independence Mall West, ~HAASPhiladelphia, PA 19105. PHILADELPHIA. PA. 19105

A World Leader in Water Treatment


Volume 13, Number 3. March 1979 263

Wet-sand air filter

Remo~al of blue haze, odor, andcondensable hydrocarbons becomessimple and economical with a unitthat draws waste gases through abed of fine, wet sand. The unit isknown as the Rader SandAir Filter, and is being offered by RaderCompanies, Inc. (Portland, Ore.).The particulate is trapped and entrained in water for removal in asettling tank, where the waste iseasily. removed. Rader says thatinitial applications are with plywood veneer dryers to reduce opacity. Other uses could be with recovery boilers, meat smokehouses, andwood-fired boilers. The companysays that the unit will also removecertain acids, and meet EPA, regional, and local air standards.

Many hazardous industrial wastescould be stabilized into an environmentally acceptable product. Leachate characteristics would meetproposed federal regulationsthrough a process based on pozzolanic microencapsulation of thehazardous wastes. The process wasdeveloped and patented by IU Conversion Systems, Inc. (Horsham,Pa.), and was originally applied toS02 scrubber sludge stabilization/disposal. lU sees applications forthis type of stabilization in wastewater treatment, battery manufacturing, electroplating, steelmaking,and other such industries that cangenerate hazardous wastes.

Destruction of toxic substances inindustrial wastewater can be accomplished through wet air oxidation, according to Zimpro Inc. Thistechnology-first used 20 yearsago, or more, to extract by-products from pulp mill liquors-couldhandle cyanide, phenols, acrolein,acenaphthene, 2,4-dinitrotoluene,and other toxics. The toxics-Iadenwastewater is mixed' with air, pressurized, and reacted at about 500of. Molecular structures of thetoxics are degraded to simpler compounds, or even reduced completelyto carbon dioxide and water.


The technology of hydrogen (H2l asan energy source should continue todevelop in the U.S., so that it wouldbecome a viable option by the turnof the century. This is a conclusionreached by a National Bureau ofStandards (NBS) workshop thatreported to the House of Representatives. At present, to be sure, thereare many difficulties with costs,storage, and production, so that H2is not practical, as yet. But theNBS group said that now is thetime io begin, at least modestly, atfirst, to overcome capital and scientific obstacles, and educate thepublic, so that this "clean" technology can eventually be introduced.

INDUSTRY

Expanded use of coal and nuclearpower to generate electricity willrestore reason to the oil market, according to the Edison Electric Institute (EEl, New York, N.Y.).EEl says that utilities have goodreason to phase out oil as a boilerfuel, because it costs 2.3 times theequivalent of energy from coal in1977, for example. In the U.S.now, about 15% of the power isgenerated with oil, but reducingthat 15% is becoming a "painfullydifficult task" because of governmental restrictions and handicapsthat obstruct new coal and nuclearplants. In particular, EEl cited thecase of two large coal-fired units ofPhiladelphia Electric, which mustchange over to oil, because of EPAair rules.

Paraho's Pjorzheimer

Shale oil production is ready toscale up to 100000 bbl/d, HarryPforzheimer, program director forParaho (Grand Junction, Colo.),announced at the National PressClub. The production would bedone with a 16-20-module processing plant to retort the shale. Up tonow, Paraho has made more than100000 bbl for the military whichhas tested, and is testing fuels refined from shale oil. Pforzheimersaid that Paraho has proposed tothe Dept. of Energy (DOE) a program to have full-size retorting

modules operational by 1981, to befunded by DOE, Paraho itself, andother private firms. He noted thatParaho's 109000 bbl already madeit the "only significant production"up to now.

A ~igorous thrust at internationaltrade will be the next major effortof the Solar Energy Industries Association (SEIA, Washington,D.C.). SEIA is working with thefederal government to broaden theinternational solar marketplace forAmerican manufacturers; its International Trade Committee ischaired by George Szego, chairman of Intertechnology/SolarCorp. (Warrenton, Va.). Also, Edward Carlough, president of theSheet Metal Workers InternationalAssociation, said that any residential solar energy installation, puttogether by workers of that union,will be fixed free of charge, if thereis any evidence of poor workmanship. Customers can phone theunion at (202) 296-5880.

The most comprehensi~e study ofS02 scrubber effecti~eness is beingconducted by Black & Veatch forthe Electric Power Research Institute (EPRI, Palo Alto, Calif.).Scrubber systems at four utilitysites will be field tested throughJune to determine capabilities ofmeeting regulations for SO" NO"as weB as not-yet-regulated emissions. These include trace elementsand organic compounds. In addition, an engineering analysis will beperformed to ascertain the qualityof equipment designs and operation. Costs, opera tions, and removal capabilities of the scrubber systems will be compared-that is a"first" for this type of analysis.

For industrial wastewater treatment, Dra~o Corp. is marketing anew system, Lectro Clear'·. Thesystem will remove suspended,emulsified, or dissolved materialsfrom liquids, and should reduce dependence on chemicals, accordingto Dravo. The system uses an electrolytic flotation method, and consists of electrocoagulation cells, flotation basins, chemical treatmenttanks, and sludge systems. Dravoacquired the technology from Swift& Company, and says that sludgeparticle size is minimal, and thatefficient separations can be performed in cold water. Sludge separation works faster, and the systemhas numerous cost-advantageousapplications, according to Dravo.

Concerned aboutcosts orefficiencyofyour

air filtration system?Then these new DuPont brochures aboutfiltration with NOM!!®are must reading!

41 different companieschose filter bags of 100%Du Pont NOMEX~oYerpolyester or fiberglass.

"NOMEX for AirFiltration" summarizes theirexperience and presents awealth of technical data to helpyou judge the worth of filterbags of Nomex'" aramid fiberto your hot air filtration system.Many graphs,

Du Pont registered trademark.

Du Pont makes NOMEX. fiber. not filtration rnateriab.

"Reducing Energy &Operating Costs inHot Cas FiltrationSystems:'

Various factors are considered in design andoperation of old or newsystems, with the goal ofobtaining cost reduction withefficiency. The role of NOMEXin reducing costs is indicatedunder different operatingrequirements, Many graphs,Three detailed case histories,

<[{IPOKP""(Co us PAT 8. fM OF'


To obtain the brochuresshown here, fill in thecoupon and send to theappropriate address, orphone:

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'-;;LEASE SEND M~.lII 0 "NOMEX for Air Filtration I

and "Reducing Energy £>I Operating Costs:' II II Name II Title II Company II Address II C~ II State ZIP__ I

..Vlw.iGi~in ll'j", .. f. d .:~,.l ~ f,, Volume 13, Number 3, March 1979 265

Preserving our visibility heritageCongress made it a national goal, and EPA will implement

this mandate with an assist from the Park Service, theForest Service and the Fish and Wildlife Service

Despite the words to a once popular song, on a clear day you can't seeforever, but you can see a mighty farpiece. In a pollution-free environment-a condition that nearly exists insome of the remote areas of our national parks in the West-the visualrange (visibility) for a large, darkobject viewed against the horizon approaches 260 km or 163 mi. In thispristine environment, visibility is limited only by the scattering of lightwaves by gas molecules present in air,or by topography or the Earth's curvature.

As air becomes polluted, visibilitydecreases, primarily because of thepresence of small particles that scatterand absorb light. However, if the colored gas nitrogen dioxide (N02) is alsopresent, it will absorb blue light anddiscolor the air a yellow to brownishred; selective scattering by particlescan also cause discoloration. Fog anddust also contribute to visual impairment. In addition, the scattering andabsorption of light by fine particlesproduce haze, which decreases thecontrast and changes the color of evennearby objects.

Prime role of fine particlesThe particles most efficient in

scattering light-which may be thepredominant effect in visibility impairment-have diameters rangingfrom 0.1-1.0 I'm. Sulfate compoundsformed in the air from sulfur oxidesemitted from stationary and mobilesources usually have diameters in thisrange, and are believed to constitutethe bulk of the offending fine particles,especially in the Southwest.

Carbonaceous soot, emitted fromfossil fuel-fired power plants and industrial boilers, and from diesel trucks,trains, aircraft and cars is also a causeof visibility impairment, especially inthe Northeast. Soot is one of the mostefficient absorbers of light.

Nitrate compounds, transformed


over time from oxides of nitrogen, alsoform fine particles of a diameter mostefficient for scattering light. Althoughthese compounds probably contributeto visibility impairment, their contribution has not been quantified.

These sulfate and nitrate aerosolsarc mainly secondary pollutants. Theybegin their life as gases that travel inair masses for hundreds of kilometersand during the course of this travel,which may comprise days, are transformed to very small particles. Becausetheir removal from the atmosphere isslow, usually by rainout, the hazeformed may be almost uniform overgreat distances.

The long-distance transport of theseaerosols makes control of visual airquality difficult. The prime reason forthis being that the cause-the polluting source-is remote from the effect-impairment of visibility.

Measuring fine particlesVisibility can easily be quantified by

the physical term extinction coefficient. which is a measure of the sum ofscattering and absorption of light byfine particles and gases. The extinctioncoefficient measures the loss of light asit travels through the atmosphere: as

this coefficient increases, visibilitydecreases. Fortuitously, it turns outthat the extinction coefficient is directly proportional to the fine particleconcentration in air when the relativehumidity is 70% or iess.

The extinction coefficient can bemeasured or inferred by using available instruments-the telephotometermeasures contrast which can be usedto calculate extinction, and the integrating nephelometer measures it directly. Color photography can furtherdocument visual air quality for studiesof human perception. Collection of fineparticles by using a dichotomoussampler allows their concentration inair to be ascertained, and chemicalanalyses can then be performed to determine their composition.

The extinction coefficient and fineparticle concentration both describevisual air quality in physical terms;however, human perception of visualair quality is an elusive, psychologicalquantity that is more difficult to document. Nevertheless, it must bequantified in some manner so that visual impairment can be correlated withperceived aesthetic damage. A Councilon Environmental Quality (CEQ)document "Visibility Protection forClass I Areas: The Technical Basis"(NTIS Number PB-288-842; thedocumcnt was based on researchsponsored by EPA) states in its executive summary that "the developmentof criteria which describes humanperception of aesthetic damage is difficult, and the entire regulatory efforthinges on it."

Although human perception ofaesthetic damage may be difficult toquantify, degraded visible air qualityis a readily recognizable effect of airpollution. And, according to RobertCharlson and his colleagues at theUniversity of Washington (Seattle,WA), the authors of the CEQ report,"From a scientific and technical pointof view, the optical effects of particles

Visibility decreases as the concentration of fineparticles increases

0.1 1.0 10 100Fine particle mass concentration, lLg/m'

-SOurce: Charlson et at Visibility Protection lor Oass I Areas: The Technical Basis, CEQ, August 1978

federally designated Class I (nationalparks and wilderness) areas (Section169A).

Under Section 165, a major source,such as a power plant, would not beallowed to locate near a Class I area ifit could not meet PSD restrictions.Section 169A reads: "Congress herebydeclares as a national goal the prevention of any future, and the remedying of any existing, impairment ofvisibility in mandatory class I Federalareas which impairment results frommanmade air pollution."

Section 169A also calls for a listingof all mandatory Class I areas; a preliminary list has already been recommended by the Secretary of the Interior; a report to Congress on met hodsavailable for implementing the national goal; and, eventually, regulations to ensure that states begin toimplement programs to achieve thegoal.

The report to Congress was due lastmonth, but the deadline was missedbecause the eontractor's draft was inadequate. EPA is making extensiverevisions to the report, which will rely,in part, on the contents of the CEQstudy. This final report is expected tobe delivered to Congress in April.

The report, by law, must containrecommendations on methods:

• for characterizing visibility impairment

• for modeling the effects of manmade pollution on that impairment

• for preventing or amclioratingthat pollution and, therefore, visibilitydeterioration.

The regulations that \I ill eventuallybe promulgated must provide guidelines to the states on the means forimplementing the goal, including theinclusion in state implementation plansof emission limits, and schedules of

Particle scattering extinction (bsp)

10-7 10~ 10-5 10" 10-.3 10-2

10-2

¥e Ec "'"Ql 10-.3 4 d'u 6iEQl '0 Ql0 15 Ol0

20c:

c: ~0 30

'u 10" 40 ~50 :0c: 75· l/l

ii 100 :>w 150

20010-5 260

aerosols declined by 38-76% at fiveNASN sites located within 70 mi ofthe smelters. Visibility improved by5-25% at locations within 150 mi ofthe smelters. Weather patterns couldnot account for this improvement.

Increased, widespread haze in themore remote, less populated areas ofthe Southwest was attributed to thediffusion of secondary aerosols and/orthe transport, diffusion and chemicaltransformation of gaseous emissions tofine particles.

However, despite this documenteddeterioration, visibilities in theSouthwest still range from 48-56 km(30-35 mi) in urban locations, andfrom 105-129 km (65-80 mi) in nonurban sites. Excellent visibility, approaching that of blue-sky (Rayleigh)scatter by air molecule, was reportedat some of the more remote sites; here,visual ranges of 145-185 km (90-115mil were recorded.

For aesthetic reasons, excellentvisibility, permitting exceptional vistas,is especially important in these rugged,mountainous areas. There is somejustifiable concern that future population increases coupled with energygrowth, if permitted to occur withoutproper control of aerosol precursors(NO, S02), could further decreasevisibility in the Southwest.

A national goalCongress recognized the fragility of

our visibility heritage and sought toproteet it, especially in the nationalparks and wilderness areas whereaesthetically-pleasing vistas are considered so important. The mechanismsfor preservation are found in two sections of the Clean Air Act of 1977which provide for prevention of significant deterioration (PSD, Section165) and protection of visibility in

are also the best understood and mosteasily measured effects of air pollution." The scientific gap lies in thequantitative relationship between thepollutant emitted at the source, andthe extinction coefficient measured atthe monitoring site. This gap, in part,results from lack of ambient air andsource data, the incompletely understood chemical conversion of gaseouscompounds to particles (aerosols) inthe atmosphere, and an inadequateunderstanding of meterologicaltransport processes, especially overrugged terrain.

Trends in visibilityIn studies conducted for the EPA,

John Trijonis and Kung Yuan, scientists with Technology Service Corp.(Santa Monica, CA), and R. B. Husar,a scientist at Washington University(St. Louis, MO) documented trends invisibility in the Northeast and theSouthwest (EPA-600j3-78-075 andEPA-600/3-78-039). In both instances, they relied on carefully selected long-term airport visibility observations, and National Air Surveillance Network (NASN) particlemeasurements at J 2 sites.

In general, they found visibility badand getting worse in the Northeast,although there were pockets of improvement. Median visibility nowranges from 6.4-19.0 km (4-12 mi) inmetropolitan areas and 14.5-22.5 km(9-14 mi) in non-urban areas.

While visibility decreased onlyslightly-about 5%-in metropolitanareas (Washington, DC, for example),there were "dramatic"-up to40%-declines in urban/suburban(Lexington, KY, for example) and innon-urban (Williamsport, PA, for example) areas of the region. Possibly themost significant finding was the shiftin minimum visibility to the summermonths.

In the southwestern U.S., visibilitytends to be "quite high" when compared to visibility in states east of theMississippi River. Visibility in theSouthwest declined somewhat in the1960's, but has improved recently tolevels observed in the 1950's. The decline is related to the increase in secondary aerosols formed from the sulfuroxide, nitrogen oxide and hydrocarbonemissions from copper smelters, fossilfuel-fired electric generating plantsand automobiles; the improvement tothe control of emissions from thesesources.

That copper smelters and their sulfur emissions were culpable in thisvisibility deterioration was broughthorne by a nine-month copper strike in1967-1968. During the strike, sulfate


Wrap upIt is clear that to achieve the na

tional visibility goal, EPA will eventually have to regulate fine particles.The only question mark is when. AsCharlson told ES& T, "There are stillserious, unsolved problems of relatingsource strengths to ambient concentrations. But, considering the wellunderstood relationship of fine particlemass to extinction, and also the presentcapability of measuring extinction directly and easily with existing instrumentation, we can be more hopefulregarding the problems of controllingvisibility degradation than abouthealth effects." LRE

tide concentration in ambient air; andsources can comply with existingstandards for SOz and TSP, and visibility may still be impaired. Furthermore, it states that PSD increments forSOz and TSP are not reliable indicators of visibility in Class I areas;therefore, there may be discrepanciesin the regulations emanating fromSections 165 and 169 that may have tobe resolved before the national visibility goal can be met.

EPA, on the contrary, feels that thePSD increments already on the books,and the NSPS for SOz (1.2Ib/millionBtu generated) being proposed forfossil fuel-fired .e1ectric generatingplants may take care of many of thevisibility problems in Class I areas forthe time being.

The National Resources DefenseCouncil, in a. soon to be publishedbook, also presents telling argumentsfor regulating fine particles, both toprotect health and visibility. For visibility protection, the Council suggeststhat a national fine-particle standardcould be set under Section 109, or regional standards, varying from oneClass I area to another if necessary,could be set under Section 169. Analternative control mechanism couldfind EPA regulating fine particlesthrough new source performancestandards.

August 1980

October 1979

AprIl 1979lateAprIl 1979

...List of Mandatory Class I Areas

published In Federal Register

Report to CongressAdvance Notice of Proposed Rulemaklng

published In Federal Register

Final List of Mandatory Class I Areaspublished In Federal Register

Proposed Visibility Regulation publishedin Federal Register

Final Visibility Regulation published inFederal Register

air quality of vistas in Class [ areas,"Jones says.

According to Jones, models that candescribe the regional haze problem"caused by the dispersion of secondaryaerosols from more than one source,"and the effect of additional powerplant sitings on already impaired visibility, are needed. Steve Eigsti ofEPA's Office of Air Quality Planningand Standards (Research TrianglePark, NC) says that Systems Application, Inc. (San Rafael, CAl has developed a single-source visibility modelfor EPA, but it has not yet been validated. Programs like EPA's VISTTA(visibility impairment from sulfatetransport and transformation) are integrating visibility measurements intotheir field studies, and these will beused to validate the visibility model.

Until this model is validated andused, and other data are available,EPA will take "a temperate approachtoward the regional problem," Bachmann says. EPA is comfortable in thisapproach, Bachmann says, becausevisibility is so bad in the East that anyadditional fine-particle pollution can'tmake it much worse and, at any rate,we don't know the effectiveness of potential control programs. In the West,visibility is not expected to deterioratefurther over the next 10 years becauseof new source performance standards(NSPS) and PSD requirements.

How to regulateDespite CEQ's recommendation,

EPA says that neither a national optical standard promulgated underSection 169, nor a national fine particle standard promulgated under Section 109 of the Clean Air Act can beproposed now because each is technologically and economically infeasiblefor northeastern states to meet. Anambient air quality standard for fineparticles (52 Ilm) may be promulgated in 1984 or 1985, however.

evertheless, a careful reading ofthe CEQ study reveals these two facts:visibility is controlled by the fine par-

Double visionVisibility problems occur on dif

ferent scales, says Kay Jones, CEQ'ssenior staff advisor for air pollution.First, there is the near-stack problem,a very localized problem; then comesthe short-distance problem, whichJones calls plume blight; and finallythere's the macroscale or synopticproblem, which is regional in scope.

The authors of the CEQ reporttackle the more difficult regionalproblem, presenting some very cogentarguments for a national optical standard based on the extinction coefficient of light and/or the control of fineparticles. EPA, however, is mandatedby law to regulate visibility withineconomic and energy strictures imposed by Congress; the first step indeveloping a visibility regulation, according to EPA, is single-source control. The agency argues that scientificunderstanding of the synoptic visibilityproblem is limited, but as knowledgegaps are filled, it will begin to tacklethe regional problem.

EPA has begun visibility monitoring; the only historical documentationof visibility trends is the visual rangeobservations of the ational WeatherService. However, the trends data are"not meaningful in terms of the visual

. compliance necessary to "make reasonable progress toward meeting thenational goal." The time, costs andenergy impacts of compliance, as wellas the remaining useful life of an existing source must be considered indetermining reasonable progress.

The EPA must also promulgate aregulation which requires that the bestavailable retrofit technology (BART)be installed on a major source which isless than 15 years old and is sited neara Class I area. This means that theolder copper smelters in the Southwestmay be exempted from meetingBART, unless a state implementationplan requires that smelters are to becontrolled as part of the state's visibility protection strategy.

Although smelters have tightenedup on their emissions by a factor of twoin the last several years, they are stillspewing out substantial amounts ofsulfur dioxide, and are major contributors to visibility impairment in thisregion. According to John Bachmannof EPA's Office of Air Quality Planning and Standards (Research Triangle Park, NC), EPA will tell Congressin its April report that even if powerplant emissions were eliminated entirely from this region, there would stillbe a visibility problem directly traceable to emissions from copper smelters.


Solar: a hot itemthat's cool, too

Honeywell is using it to meet the majorportion of its General Offices building's heating,

hot water, and air conditioning needs

Collectors: Harnessing the slln in Minneapolis

"Solar energy use in Minneapolis? It'llnever work," declared SnodgrassSchnickelfritz, president of Preconceived Notions, Inc. (Wiseacre,Calif.).

If Schnickelfritz's evaluation iscorrect, then Honeywell Inc. (Minneapolis, Minn.) must be making thegranddaddy of vain efforts, because itis equipping its new General Officesbuilding with a solar energy system-the largest of its kind in the U.S.That system will provide 84% of theannual cooling energy, 53% of the annual heating energy, and 100% of thehot water needs of the eight-storybuilding, which has 100 000 ft2 of floorarea that is normally occupied byabout 500 people.

Trough-type collectorsThe solar collection system consists

of 20 250 ft 2 of trough-type collectors

developed by Honeywell. These collectors rest on a steel support structurebuilt above a five-story parking ramp.The collected thermal energy, at 350of, is piped undcrground, over 300 ft,rrom the parking ramp to solarhea ti ng-ventila tion-a ir condi tioni ng(HVAC) equipment in a first-floormechanical room in the new building.

The actual system has two majorflow loops. A primary (collector) loopsupplies the 350 0 F energy with 390gpm of heat-transfer oil ("Therminol44"), whose acceptable viscosity isretained during the rigorous Minnesota winter. The secondary loop uses460 gpm of "Caloria HT 43" at aheat-transfer medium for buildingheating, cooling, and hot water. Thethermal energy is converted to HVAC,in the mechanical room, in response tobuilding load demand. Any excess

solar energy is piped to two underground thermal storage tanks. Controls and alarms are handled by a sophisticated automatic system.

The trough-type collectors reflectsolar energy onto steel absorber tubesat their parabolic focal lines, andconsist of 20-ft modules assembled intoforty-two 120-ft rows. To rollow thesun, each row is driven individually bya center-mounted motor jgear train;the rotational axis is oriented eastwest. Also, each row individuallytracks the sun's elevation by means ofa photosensitive sensor, motor-driveelectronics, and a motor/brake assembly. The 42 rows are connected inparallel.

The absorber, itself, is a 1.25-in.diameter steel tube plated with blackchrome, and is contained within aninsulated housing, with an etched,tempered low-iron glass window. Its


The heat's on

The system pumps 182 gpm ofsolar-heated oil into a shell-and-tubeheat exchanger. Heat is transferred tohot water for the building's radiantbaseboard heating system. Control isexercised by an outdoor air thermostat.Solar-heated water nows through aconventional steam converter for eachzone, to provide energy needed to meethot water supply temperature requirements.

Fully 100% of the domestic hotwater is solar-provided. This is accomplished through a separate circulating loop, and two 120-gal "doublewall" hot water heaters.

Thermal storage is in two 18 000gal underground steel tanks with amixture of "Caloria HT 43" oil (49%by volume) and small rocks, 0.375-1.0in. in diameter (51% by volume). Useof the rocks reduces oil costs, and addsto tank thermal capacitance.

Computer controls

The solar energy now from collectors to storage to the HVAC system ishandled by electro-pneumatic automatic control. The control system offers a capability to charge, discharge,and sequence one or both of the thermal storage tanks, so as to maximizesolar collection/conversion efficiencyfor HVAC.

The "brain" of the control system isa Honeywell Delta 1000, which willnot only handle HVAC and energyconsumption, but also provide fire andsecurity control. In the HVAC part,the computer receives data necessaryto command optimization of air, water,and heat-transfer nuid now.

Computer control also helps to runthe HVAC system so that peak loadsare met, and, for example, for cooling,electrical draw charges can be minimized. Reduction in this draw could be3433 kWh, or 12%, on chilled waterreset, alone. Total electrical draw reduction for cooling is about 20000kWh with an air economizer, and25000 kWh more, because of solarenergy. For heating/hot water, commensurate benefits are enjoyed.

So Honeywell is showing that evenin a relatively cold climate like that ofMinneapolis, solar HVAC can workquite well. It appears, then, that Preconceived Notions, Inc. "goofed" withits evaluation. Eat your heart out,Snodgrass Schnickelfritz! JJ

reduces cooling electric power consumption. But if nuid temperaturegoes above 300 0 F, a variable-speedcontrol mode will cut off the electricmotor, and the system will "go entirelysolar."

18,000gal

storagetank

East zonehot water

radiantheating

West zonehot water

radiantheating

Pump

Solardomestichot water

18,000gal

storagetank

Expansiontank

the solar-driven R/C turbine, if solarenergy is unavailable.

The solar nuid-now rate is 230 gpmat 300 0 F, and the condensing waternow rate is 330 gpm at 85 0 F. Underthose conditions, solar energy consumed is 1.39 million Btu/h, for athermal-to-mechanical R/C conversion efficiency of 15.6%.

The Rankine is a low-temperaturetwo-phase cycle whose working nuidis refrigerant "RII3". The "RI13"vapor, at 275 0 F and 113 psi is ex·panded to 178 0 F and 10.3 psi, therebyproviding the needed 85 hp. The R/Csystem was designed and built byBarber-Nichols Engineering (Denver,Colo.).

In constant speed mode, the R/Cturbine shaft power unloads the waterchiller compressor motor torque, and

100-tonRankine

cyclewaterchiller

Source: Honeywell, Inc.

Solar energy system

collection efficiency, at 350 0 F, is estimated to be 60%. The parabolic renector is an aluminum honeycombsandwich with an adhesive-backedaluminized acrylic film.

Cool it!

Two Rankine cycle (R/C) powersystems are supplied with "Caloria HT43" oil, solar-heated to 300 0 F. At thattemperature, the 85 hp needed to drivetwo lOO-ton water chillers is produced.These chillers are somewhat modified,conventional open centrifugal unitsthat furnish chilled water for a distributed air-cooling system. The22 ODD-rpm R/C turbine is coupled tothe 3600-rpm chiller compressor motorby means of a gear box containing amechanical over-running clutch. Anelectric motor gives a 100% backup to


A new membrane system which uses neither reverse osmosisnor ion exchange will, according to its developer,

Innova, Inc., allow you to

Choose the ions you want

Some prioritiesPriorities for pilot-plant develop

ment comprise preparation of foodgrade phosphoric and superphosphoricacids, and recovery, for eventual sale,of uranium and vanadium from phosphate mining wastes. Nohren andMoeglich say that the cost of acidmanufacture should be "substantiallylowered" when black phosphoric acidis made into acid equivalent to thatwhich is acceptable for use in the foodindustry, by ion separation. Thepresent method for making food-gradeacid is to oxidize elemental phosphorusin an electric furnace.

around boundary layer phenomena;that is, particle behavior at the liquid-membrane interface.

"Development of our process is justout of the lab stage. On the basis ofindependent test results of our system,we are presently ready to proceed to apilot-plant stage anywhere," Nohrensaid.

.......'Ion selection. Nohrell alld Moeglich with an apparatus concentrating Cr+ 6

among the ion species," Nohren said."Nobody we know of makes a similarmembrane," he told ES& T.

Started in defense workNohren said that he founded Innova

in 1969, to do research and development work for the Department of Defense. "Our field was the advancementof the state-of-the-art of manufacturing technology. But Innova got intoenvironmental efforts a few years ago,because of problems the Army washaving meeting EPA requirements,"Nohren recalled. "This field lookedpromising, as it was new, large, andwithout satisfactory technology, so webegan to augment our research staff,and zeroed in on selected applicationsfor industrial waste treatment andchemical processing," he said.

Nohren expressed his belief that theroad to this development was found inthe field of particle physics, which ischief scientist Moeglich's specialty. Healso said, "The Innova process centers

Innova president Nohren"it will meet 'best available' "

The Erlenmeyer nask, standingunder the laboratory hood, containeda clear, green solution. 'The greensolution? That's pentavalent vanadium," Karl Moeglich, chief scientist atInnova, Inc. (Clearwater, Fla.), toldES& T. "The vanadium is part of thephosphate mining industry's wastesfrom Idaho rock. With our system, wecan recover the vanadium selectively,completely, and economically. In oneinstance a company is losing about $10millionjyear worth of vanadium to itstailings and fertilizer acid," Moeglichsaid.

Not reverse osmosisSelective cation and anion removal

is made possible through a proprietaryion transfer membrane technologywhich can include unialysis or dialysis."But the technology doesn't involvereverse osmosis, or ion exchange,"Innova president John Nohren said."There's no osmotic pressure. Also, wedo not have an ion exchange systemhere, as there are no implanted ions.The membranes are essentially hydraulically inert, and don't swell, clog,or pump water. They can be renderedpermeable in one direction-selectivefor either anions or cations," Nohrenpointed out.

"Our membranes will allow positiveand negative ions to pass through simultaneously, in cross now. Yet, nointernal chemical reactions take place


Michael Baker Corp., the engineering firm,found such a case for a

copper producer in Michigan

Whenexisting controls

are adequate

In determining what to do aboutwastes from wet-mined phosphaterock, such as is mined in Florida andNorth Carolina, one must take uranium and its "daughter elements," suchas radium and radon, into account.Moeglich told ES& Tthat his company's system can remove the uraniumselectively, so that it can be concentrated in such a grade as to be marketable. He and Nohren said that thesame can be done with other heavymetals, with their concentrations incleaned, reject, or rinse water reducedto below 1984 discharge standards"even to 0.01 ppm, as we have done,and have had verified through independent tests, although for practicalpurposes, a zero-discharge systemcould be provided."

Moeglich pointed out that Innova'stechniques of uranium and vanadiumextraction might cost half what solvent-extraction technology normallycosts. He also said that costs of thecompany's proprietary method wouldbe competitive with those of pondlining to contain wastes.

One particularly troublesome waterpollutant is hexavalent chromium(CrH ). Nohren said that the Innovasystem can collect CrH ions, andconcentrate them to 10%. This concentration would make the recoveredCr+6 suitable for reuse for electroplating purposes, he noted. The technique would be to concentrate Cr+6

from the plating rinse, and to recyclethe cleaned water to plating shop use,as well.

For the future

Nohren said that in the future, hesees Innova's system as being able tohandle or eliminate wet-mined phosphate wastes. He believes that not onlycan uranium be recovered and eventually sold, but "so can phosphatevalues presently found in the minetailings of yesteryear, and in lowergrade ores, economically." Rejectwater from phosphate or gypsumponds, treated by the new method,would more than meet "best available"standards, Nohren predicted, withrecovery of valuable materials.

Then, Moeglich picked up a oneliter Erlenmeyer nask from a laboratory table. The nask was filled withwater, and there was about one inch ofwhite powder at the nask's bottom."The white precipitate? That's beenconcentrated from about 40 gallons ofour tap water run through our system,"Moeglich said. "The solid material ishardness in what is distributed andsold as generally soft, potable water. Itgives you some food for thought,doesn't it'" JJ


Michael Baker Corp., the engineering firm that designed much of theI\laska pipeline, including a suspensionbridge over the Tanana River that canwithstand an earthquake of 7.5 on theRichter scale, has been one of the top20 engineering design firms for thepast 20 years.

One of its many projects, especiallyone for the environmental watcher, isan environmental assessment of theWhite Pine Copper Division mining,milling, smelting and refining operations on the Upper Peninsula inMichigan. The White Pine CopperDivision of Copper Range Companyoperates the second largest underground copper mine in the U.S.

White Pine has the capacity to mineand process 25 000 tpd of ore, resultingin an annual copper production of 162million pounds. The present operationstarted in 1955. In 1976 copper production was curtailed at White Pinebecause of depressed copper prices. I\tfull strength, White Pine had a workforce of about 3000 persons; however,in the foreseeable future, it is expectedto operate at a reduced capacity.

Baker project manager, John B.Wakelee, III, said that the White Pinecopper has a high silver content(0.06%) that gives the White Pinecopper a high combination of electricaland thermal conductivity and strengthin copper's service temperature range;this helps White Pine's competitiveposition in spite of the currently depressed copper market. However,general operating costs remain relatively high, as the company is totallydependent upon underground ores.

The water for White Pine's mill andsmelter operation is obtained from

Lake Superior. At an ore production of15000 tpd, 18.65 million gallons perday of water are withdrawn from LakeSuperior. About 18 million gpd areused in the mine, mill, smelter andpower house operation; the 0.65 million gpd is used for potable water forboth the plant site and the town ofWhite Pine, after filtration, chlorination, and nuoridation.

Wastewater from the operation,consisting primarily of tailings waterfrom the milling process and sitedrainage, is pumped into tailings basins. In addition, approximately onemillion gallons of highly saline wastewater must be pumped daily from themine to prevent nooding. All minewaters are also pumped into the tailings basins.

White Pine has two tailings basins.The first one was used until 1971,when it had been filled with approximately 90 million tons of tailings. Thesecond basin, with a design capacity of250 million tons, is currently being

Baker program manager Wakeleeadvi.<es agaillst additiollal cOlllrols

The plant. SlIIelln appears (lawer parlioll of Ihe pholo) righl of Ihe 504-ji slack farelllissiol1SfrOIll il alld Ihe I"Mer plam, Ihe ImiMillg alllhe righl

2

35

used, At the present rate of production.this basin will be full in about 30-50years,

The treated wastewater dischargedfrom these basins has been shown tohave no significant adverse environmental impacts on the Mineral Riveror Lake Superior, Nevertheless. thisdischarge is subject to both federal andstate regulations and requires a discharge permit under the PDES,White Pine was issued a NPDES permit in 1975. which was revised in 1977.and comes up for renewal this year(1979) when its five-year term expires(ES& T. January 1979, p 32),

Further revisions of the NPDEScould inelude designating the MineralRiver as a receiving stream, hence requiring application of Michigan standards for receiving waters and requiring best available technology economically achievable, Alternatively,direct discharge of mine water to LakeSuperior and methods of treatmentwere evaluated, The treatment methods consisted of caustic soda andchlorine production and/or concentration and mine storage, Anotheroption: 80-85% of the mill processwater could be recycled tailings basinwastewater, any of which would addadditional environmental problemsand expenses to the White Pine operation. which is already demonstratingno significant negative impact on thewater environment.

Air emissions

A principal source of air emissionsat White Pine is the smelter. Anothersource is the coal-fired boilers of theelectric power generating plant.

John Wakelee said that t'he Baker

report found that the need for additional air pollution controls at WhitePine smelter is not apparent. The S02cmissions result from the operation ofthe reverberatory rurnace and converters; the matte is reduced to blistercopper by blowing air into the converters, and oxidizing the iron andsulrur in the matte to FeO and FeJ04and gaseous S02. The gas has a relatively low S02 content because or thelow sulrur content or the White Pineore (chaleocite),

Because or the short. intermittentnature or the converting cyele, thevolume and sulrur content or the converter exhaust gases arc highly variable. The converter exhaust gases arcdischarged to the atmosphere throughthe main stack along with the reverberatory furnace waste gases, The Pa,engineering design rirm found thatground level S02 and particulateconcentrations arc substantially belowthe national ambient air quality standards, In ract, the region has beendesignated as an attainment area rorS02 and particulates by the U.S,EPA,

Even so. White Pine could be racedwith the cost of installing additional airpollution controls under the Clean AirAct Amendments of 1977. Nevertheless. because of the low SO, concentration in the stack gas, th~ conventional acid plant system or sulrur removal would not be reasible at WhitePine,

White Pine remains a high costcopper producer. Additional water andair pollutant controls at White Pinecould have serious adverse economicimpacts with no signiricant beneficialenvironmental consequences. SSM

6

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1, Methylene Chloride2, Chloroform3, 1, 2Dichloroethane4, Trichloroethane5, Bromodichlorornethane6, Dibromodichlorornethane

Tenax Column-Temp, programmed,

Chloroform and other potentiallycarcinogenic compounds in waterare SELECTIVELY detectedwith the Tracor 560 GasChromatograph and HallElectrolytic Conductivity Detectoro Chloroform by direct

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Tracor InstrumentsTracor, Inc,6500 Tracor LaneAustin, Texas 78721Telephone 512:926 2800



Analysis of pollutants

I I: 15 A Computer Survey of GC-MSData to Determine Organic PollutantDistributions in Industrial Effluents-Waiter M. Shackelford, U.S.Environmental Protection Agency,Athens, Ga.II :50 Lunch

Afternoon Session-I :30-5:30I:30 A Comprehensive Scheme forAnalysis of Organics in EnvironmentalSamples-Edo D. Pellizzari, ResearchTriangle Institute, Research TrianglePark, N.C.2:05 Critical Comparison of Methodsfor Preconcentration of Trace Elements from Water-Donald E. Leyden, University of Denver, Colo.2:40 Analysis of Organics in Aerosols-Frank W. Karasek, Universityof Waterloo, Ontario, Canada3: 15 Break3:45 Trace and Micro Analysis Usingthe Ion Microprobe-George H.Morrison, Cornell University, Ithaca,N.Y.4:20 Distribution Register of OrganicPollutants in Water-Mark Marcus,Midwest Research Institute, KansasCity, Mo.4:55 Analytical Photoacoustic Spectroscopy: Potential and Applications-Gordon F. Kirkbright, ImperialCollege, London, England

Tuesday, May 8Morning Session-8:30-12:25

8:30 Plenary Lecture-Robert H.Harris, Environmental Defense Fundand University of California, Berkeley,Calif.

9:30 Fundamental Problems Related toValidation of Analytical Data-Warren B. Crummett, Dow ChemicalCompany, Midland, Mich.10:05 Break10:40 Liquid Chromatography UsingCapillary Columns-Milos Novotny,Indiana University, Bloomington,Ind.II: 15 Persistence and Accumulation ofOrganochlorine Compounds: ThePattern of Their Global Distribution-Karl-Heinz Ballschmiter,University of Ulm, Ulm-Donau, Federal Republic of GermanyII :50 Environmental Analyses-AChallenge to Multielement Techniques-Charles H. Anderson, U.S.Environmental Protection Agency,Athens, Ga.12:25 Lunch

9:30 Data Quality Assurance Needs forMeasurement of Toxic SubstancesC. C. Gravatt, National Bureau ofStandards, Washington, D.C.

10:05 Break10:40 Analysis of Particulates by LaserRaman Microprobe-Michel Delhaye,University of Lille, Villeneuve d'Ascq,France

can Chemical Society became sponsors. Their continued sponsorship hascontributed significantly to the successof this symposium.

With Basel, Switzerland, as the sitefor the 1974 symposium, participationand sponsorship by the European scientific community promoted international communication. To continuethis international exchange of ideasand experiences, the symposium nowis held alternately in Europe and theUnited States. In 1975, the site wasJekyll Island, Georgia; in 1976, Vienna, Austria. After convening at LakeLanier, Georgia, in 1977, the symposium returned to Switzerland for the1978 symposium in Geneva.

For further information, contactElaine McGarity, EnvironmentalProtection Agency, EnvironmentalResearch Laboratory, College StationRoad, Athens, Georgia 30605. Phone404/546-3184.

Plan to attend the Ninth Annual Symposiumon the Analytical Chemistry ofPollutants.

It will be held May 7-9 at Jekyll Island, Ga.Here is the program

'\919&lla,/ ,. f S''I' M ,. '1'J 3 4 S

S~O '\'\ '\2-6 1 8 '\1 '\8 '\9

13 1 2. ;; 2.4 2.5 2.620 2'\ ~9 30 3'\21 28

The symposium is designed tobring together people concerned withthe application of analytical chemistryto environmental problems. Appliedchemists will learn about the latestdevelopments in a broad range of analytical techniques. Researchers willmeet and talk with chemists who willapply these newly developed techniques. Plenary lecturers will representdiverse viewpoints concerning implementation of the 1976 Toxic Substances Control Act. Other invitedspeakers will present a balanced, relevant program concerning analysis oforganic and inorganic environmentalpollutants.

The first two symposia in this serieswere held at Halifax, Nova Scotia,Canada, in 1971 and 1972. The thirdsymposium took place in Athens,Georgia, in 1973, when the U.S. Environmental Protection Agency, theUniversity of Georgia and the Ameri-

Monday. May 7Morning Session-8:30-11 :50

8:30 Plenary Lecture-Donna Roberts, Director of Product Stewardship,Dow Chemical Company, Midland,Mich.

274 Environmental Science & TechnoloQv

Evening Session-7: 15-10:00

7: 15 Identification of Species in PolarLiquid Chromatographic Eluents UsingCoherent Raman Spectroscopy-L. A.Carreira, University or Georgia, Athens, Ga.

7:50 Detection of Chemical Species inthe Atmosphere by Sampling and Analyzing Precipitation-Jacques Slanina. Energy Research FoundationECN, Petten, The Netherlands8:25 Break

8:50 Some New Luminescence Methods for Environmental Analysis- A.Townsend. University or Birmingham,England

9:25 Mixture Separation by CarbonChromatography and ComponentIdentification by LC-MS-David L.Stalling. U.S. Fish and Wildlire Service. Columbia National FisheriesResearch Laboratory, Columbia,Mo.

Wednesday, May 9Morning Session-8:30-11 :50

8:30 Plenary Lecture-John B. Ritch,Jr., Director, Orrice or Industry Assistance, Orrice or Toxic Substances,U.S. Environmental ProtectionAgency, Washington, D.C.

9:30 Natural Variabilities in Sampling- Robert J. Huggett. VirginiaInstitute or Marine Sciences.Gloucester Point. Va.10:05 Break

10:40 Isotope Dilution Mass Spectrometry for Accurate Determinationof Elements in Environmental Samples-K. G. Heumann. University orRegensburg. Federal Republic orGermany

II: 15 GC-MS Analysis of OrganicCompounds in Rivers-Ronald A.Hites. Massachusetts Institute orTechnology. Cambridge. Mass.

11 :50 Lunch

Afternoon Session-I:30-3:15

1:30 Analysis of Disinfection ByProducts in Water and WastewaterWilliam H. Glaze. North Texas StateUniversity. Denton. Tex.

2:05 Surface Spectroscopic Examination of Particulates-David M. Hercules. University or Pittsburgh. Pittsburgh. Pa.2:40 Methodless Methodology Appliedto Trace Organic EnvironmentalAnalysis-David H. Freeman. University or Maryland, College Park,Md.

3: 15 Adjourn

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The bubble concept

Michael R. DelandERT, Concord, MA

"If a company can, with equivalentenvironmental impact, get S02 out ofone process for 50 cents a pound andout of another for $1.00, we shouldpermit the company's engineers tocontrol more of the first process andless of the second," said EPA Administrator Costle in providing guidanceto the states on the "Bubble" concept[44 Fed. Regist., 3740 (Jan. 18,1979»).

The purposes of the concept are:• to "provide greater flexibility to

sources to effectively manage their airemissions"

• to meet water effluent limitationsat the "least cost." This flexibility iscreated by placing an imaginary"bubble" over all or part of a plant andapplying single emission or dischargelimits to the "bubbled" portions,thereby replacing the traditional"stack by stack" or "pipe by pipe"controls.

The concept allows sources to expand and increase air emissions orwater discharges by "offsetting" theincreases within the source or to control more economically existing emis-

, sions. In other words, certain "progressstifling" regulations can be avoided if"no net increase" in air emissions orwater effluents occurs at the source.The bubble concept is one of many

."market style" or economic alternatives being considered by EPA with the

, aim of providing more flexible, costeffective, pollution controls while notjeopardizing the Agency's effort to

; clean up the environment.

In air, the concept is currently applied differently for Prevention ofSignificant Deterioration (PSD) or"clean areas" than for nonattainment(NA) or "dirty" areas. The PSD regulations [43 Fed. Regist., 26380 (June19,1978») specifically incorporate thebubble concept. While applied somewhat differently to the technology review than to air quality impact analysis, exemptions are available from boththese reviews if no net increase of anapplicable pollutant occurs at thesource.

In NA areas, the final modificationto EPA's "offset ruling" [44 Fed.Regist., 3274 (Jan. 16,1979») does notprovide for "bubbling." This reflectsthe policy belief that the need to reducenew emissions as much as possible in a"dirty" area is _greater than in a"clean" area. However, also reflectedis the heated debate within EPA,which predictably resulted in a compromise giving the states, rather thanEPA, the option to "bubble." Theoffset policy expires once the revisedState Implementation Plans (SIPs) areapproved by EPA.

The Agency in its January 18 policystatement specifically encourages thestates to make use of the "bu1:)ble"within those plans. Again, Costle citesthe possible cost savings which "mayhelp move some industries from aposture of belligerence to one of cooperation as they work with us tochoose among possible solutions."

It is important to note that thebubble concept was specifically addressed in a D.C. Circuit Court opinion [,ASARCOv. EPA, II ERC 1129D.C. Circ. 1978») in which the use ofsuch an exemption was expressly disallowed in regard to New Source Performance Standards (NSPS). EPAfeels that bubbling would not.frustratethe air quality protection purposes ofPSD. But the use of this concept by

-EPA in thePSD regul:;!tions and by thestates for NA areas may well give riseto similar litigation.

At the moment the water bubble has

not been inflated. The concept is thesame as in air, allowing lesser controlfor pipes where control costs are higherin exchange for additional treatmenton other discharge pipes where controlis cheaper. However, the ASARCOproblem in concert with additionallegal questions concerning the definition of "point source" have intensifiedinternal EPA debate to the point wherea proposal outlining the bubble approach to directors of state water programs has been withheld.

Future of the bubble

The bubble concept represents agenuine effort by EPA to provideflexibility and cost savings to pollutioncontrol-yet its future is very much indoubt for it directly joins economic andenvironmental issues. Its many criticsclaim that it is designed to maintainthe status quo, while the intent of theClean Air And Water Acts -clearlycalls for environmental improvement.

In air, the formal comment periodon EPA's policy statement closesshortly (March 18, 1979), although afinal policy is not expected until May.But the real arena is at the state leveland ample opportunity still exists forinput. For example, it can be arguedthat EPA's concern about enforceability makes its proposed policy statement so constraining as to severelylimit the practical application of the"bubble."

In water, it seems clear that, barringsubstantial new pressure, EPA, givenits internal dissention, is now reluctantto lead the way.

The bubble concept does provide theincentive for industrial innovation andcould become an example of a sensiblebalancing between environmentalcontrols and costs. The next fewmonths should tell whether this majornew initiative in pollution control willexpand to its potential and become aneconomic boon, or will be punctured bythe barbs now being aimed at it andbecome an environmental bust.

~ 0013-936X/79/0913-0277$01.0010 © 1979 American Chemical Society Volume 13, Number 3, March 1979 277

Natumtcarcinogenic products

Not all cancer-causing substances are man-made. Nature does afair share ofproducing compounds that are potential toxins wheningested; fortunately, many of these toxins are weak carcinogens

Elizabeth K. WeisburgerNational Cancer Institute

Bethesda. Md. 200/4

There are many statements in thepopular press that cancer results fromexposure to pollutants emanating fromthe increase in technological developments. However, certain historicaldocuments indicate that lung cancer,for example, often associated with airpollution or excess smoking, was alsoknown in Germany during the MiddleAges.

Lung cancer, which occurred among

the cobalt miners of the Schneeberg inSaxony, was described by Paracelsusin 1531, and by Agricola and othcrswho called it "Bergkrankheiten"(mountain disease). At that lime thedisease was mistaken for tuberculosisof the lung. This ailment, which alsooccurred in the miners working in theloachimsthal of eastern Germany, wascaused by exposure to uranium, radium, and their daughter productspresent in the ores mined in these locations.

It is currently evident that modernminers on the Colorado Plateau encounter the same risks as the Germanmincrs, cspccially when exposure to

uranium and its daughtcrs is combinedwith smoking. Thus, an occupationaldisease related to a "natural" productwas first noted almost 450 years ago.

Culprits: natural organicsOther naturally occurring inorganic

compounds arc associated with an increase in cancer rate. Examples arearsenic and several other metalspresent in drinking water in certainareas of the world. However, naturallyoccurring organic compounds aremuch more prevalent among the listsof natural carcinogenic products.

A research group showed in 1942that crude ergot was tumorigenic in

278 Environmental Science & Technology This article not subject to U.S. Copyright. Published 1979 American Chemical Society

animals fed this compound for sixmonths or more. Since the tumorsgenerally regressed when the ergot wasdiscontinued, this was indicative of arelatively benign effect. The consLituents of ergot responsible for this actionhave not been investigated

In the early 1950's. it was reportedthat subcutaneous injections of tannicacid or tannins induced an appreciablenumber of liver tumors in both rats andmice. The data were somewhat contradictory and have not been fullyconfirmed, especially in view of thesomewhat artificial method of administration used. For this reason, thecarcinogenicity of tannins and tannicacid for a route pertinent to humanexposure is questionable.

During the 1960s. it was first reported that safrole caused liver tumorsin animals fed the substance at highdose levels. Safrole, which occurs inmany natural oils such as anise, camphor or sassafras oil, was previouslyallowed as a synthetic navoring agentin beverages and foods.

As a result of the tumor-inducingproperties of safrole, reexamination ofthe GRAS (Generally Recognized asSafe) list, which includes safrole, wasdeemed necessary by the FDA. Safroleis partially metabolized by hydroxylation to I '-hydroxysafrole, which isfurther metabolized to I-acetoxysafrole, which is considered the likelyactive carcinogenic intermediate.

In an attempt to identify the agentresponsible for the high incidence ofamyotrophic lateral sclerosis in Guam,the National Institute of NeurologicalDiseases and Blindness tested variousplant products used on that island, including the nuts of the cycad plant.These nuts were used as an emergencystarch when typhoons had destroyedother food sources. Many differentvarieties of the cycad plant «(ycascircinalis). which is a member of anancient plant family. grow in tropicalor subtropical areas.

The nuts, about the size of a lemon.and the outer husk are the parts usedin Guam. The husk is chewed by people working in the fields: the nut is usedas a starch after it is soaked in water toremove the toxin. The toxic material iscycasin. the glucoside of methylazoxymethanol, which is the active moiety.

Cycasin causes liver, kidney andintestinal tumors in rats and otherlaboratory animals. It also has neurological effects since cattle grazing oncycads, often the only green forage intimes of drought, may show paralysis.

In Kenya, the kernels of the plantEneephalartos, also a member of the

Cycasin. The nuls and husks (above) ofIhe (Jcad (below) I'lalll. which colllain Iheloxin cyca.l·in. are used a.1 food hy Ihepeople of Guam; husks are chewed. andIhe nulS are soaked and used as a slarch

Peanuts. Moldy {,,'anUIs conlain Ihedeadlr loxinaflatoxin

cycad family, are consumed both byhumans and by cattle. In this verylarge kernel, the toxic compound ismacrozamin, which is also carcinogenic in rats, causing kidney, liver andlung tumors similar to the effect ofcycasin.

Edible but toxicIn many areas of the world poison

ing of domestic animals by plants ofthe Senecio. Heliotrope and erotaIorio species has been reported.Senecio species are quite widespread,and some forms, such as "golden ragwort" or Senecio aI/reus. are found in

orth America. These aster-likeplants arc quite toxic to the liver because detoxification of ammonia fromdietary nitrogen is blocked. Thusgrazing animals which eat these plantsoften die from ammonia intoxication.

In many African countries theSenecio plants. especially S. jacobaea,arc used as herbal medicines despitetheir toxicity. Most of these plantscontain one or the other of the pyrrolizidine alkaloids such as retrorsine,isatidine and lasiocarpine. Honeymade from such plants may be contaminated by these alkaloids, some ofwhich are also liver carcinogens inrats.

In Japan, plants known as coltsfootare used as herbal remedies or as vegetables. Several of these are also carcinogcnic to the livers of rats. Apparently, onc compound responsible is analkaloid, petastenine, which has astructure similar to that of the pyrrolizidine alkaloids isolated from theSenecio plants. Also. there is a recentreport that a plant called comfrey,which is used as a poultice or as a tea,has a carcinogenic effect in animals.

One may question the use of herbalremedies or sassafras tea in modernsociety. Nevertheless, until severalyears ago one of the materials used tonavor vermouth. a constituent ofpopular drinks such as martinis orManhattans, was a root of an Indian(Jammu) variety of calamus.

The American variety of this plantis Acarus calallll/s or sweet nag. Thisplant was used by the American Indians and others as a navoring agent orfolk medicine. In 1967 it was foundthat {:I-asarone, about 85% of the navoring material in Jammu calamus,caused intestinal tumors in rats. Thusthe usc of calamus as a navoring material for American vermouth was nolonger allowed by thc FDA. Because ofcertain structural similarities betweensafrole and {:I-asarone, one might assume analogous pathways for activation of {:I-asarone and safrole.

Volume 13. Number 3. Mareh 1979 279

Another compound with similarfeatures is estragole, a component ofoil or estragen or oil of tarragon, obtained from the tarragon plant, Artemisia dracunculus. Recent studieshave shown that estragole has a definite but weak liver carcinogenic effectin young male mice. Since tarragon isoften used as a flavoring agent ingourmet types of vinegar, naturallyoccurring carcinogens may be consumed by those living sophisticatedlifestyles.

Another gourmet-type food is a wildmushroom, the false morel (Gyromilraesculenta). This mushroom containsN-methyl-N-formylhydrazine, whichcauses several types of tumors when

_given to mice in their drinking waterfor their lifespan.

Active ingredient unknown

In the previously mentioned plants,the carcinogenic components havegenerally been identified. However,there are other carcinogenic plants inwhich the active component has notbeen characterized. One of these is thebracken fern, a common inhabitant ofopen woods and waste places. Theyoung shoots, called the fiddleheads orcroziers, are eaten as a springtimedelicacy in many countries.

Cattle that often graze on brackenfern are found to have bladder orstomach cancer; this is especially so inTurkey, Scotland and Wales. To someextent the effect of bracken fern inexperimental animals can be inhibitedby simultaneous administration of theenzyme-inducer phenothiazine.

Various compounds have been proposed as the active component inbracken fern. However, numerous efforts to fractionate and characterizethe active material(s) have not beenproductive.

Of all carcinogenic plants, the onewith the greatest exposure is probablythe tobacco plant. There continues tobe much controversy over the excessrisk of lung and bladder cancer fromsmoking cigarettes. Since tobaccosmoke contains dimethylnitrosamine,benzo(a)pyrene and numerous otherknown carcinogens, the probability ofa risk from continued long-term exposure would seem high.

The gas phase contains nitrosamines, hydrazine, vinyl chloride, andseveral other toxic materials. Theparticulate phase contains numerouspolycylic aromatic hydrocarbons ofvarying carcinogenic potency. In addition, some of these substances, atleast in animal experiments, have anorgan-specific effect, especially for theesophagus, lung, pancreas and bladder.


Further studies indicate that at leastfour nitrosamines are present in unburned tobacco itself. One of these,N-nitrosodiethanolamine, was foundpreviously to induce liver cancer inrats.

Endogenously formed carcinogensmay also represent a hazard. There hasbeen much publicity and controversylately over N-nitroso compoundsformed in the digestive system fromnitrite and secondary or tertiaryamines.

Another case of interest is the formation of ethyl carbamate or urethanein foods or- beverages processed byfermentation. Ethyl carbamate is aweak carcinogen but does cause lungtumors in mice, or liver tumors in miceor newborn rats, although adult ratsare resistant to its action. Foods andbeverages such as beer, wine, bread,olives and yogurt all-contain measurable levels of the compound, which isprobably formed :by reaction of endogenous carbam'yl phosphate withethanol to yield ethyl carbamate.

Microbes make carcinogens

Even microorganisms can synthesize carcinogens. Some of these toxins,when ingested, affect more people thanany other unintentionally ingestednatural carcinogen.

Fungus. Aspergillus flavus on moldy grainsproduces aflatoxin. which is a potent livercarcinogen

In 1960, an outbreak in England ofa fatal liver disease in turkey poultswas traced to peanut meal in their feedwhich had been infested with the fungus Aspergillus j7avus. This fungus iscapable of producing some very toxiccompounds such as aflatoxin B I and

B2, lesser quantities of aflatoxin G Iand G2, and several other compoundswhich have not been thoroughly investigated.

Aflatoxin BI is one of the most potent liver carcinogens in rats or rainbow trout. In certain strains of rats fed0.1 ppm of aflatoxin B1 for 50-80weeks there was a 50% incidence ofliver cancer; even 0.015 ppm was effective after 68-80 weeks. Rainbowtrout were affected by levels as low as0.1 ppb. On the other hand, adult miceare quite resistant to aflatoxin.

The fungus can contaminate manytypes of grains or oil seeds such as rice,corn, cottonseed meal, and copra.Cows fed meal containing aflatoxin BIor B2 excrete aflatoxin MI or M2 in themilk. These compounds represent detoxification products; they are muchless toxic to rats, and do not inducetumors in rats under conditions whereaflatoxin BI does.

In warm, humid areas of the worldthe aflatoxin contamination of foodcrops can often be correlated with livercancer incidence in the population.Data supporting this supposition havebeen obtained from Swaziland, Kenyaand Thailand.

Another compound, similar to aflatoxin, is sterigmatocystin, producedby Aspergillus versicolor or Aspergillus nidulans. Although this compound is carcinogenic in rats and mice,it is considered for use as a chemotherapeutic agent in the treatment ofneoplastic (tumor-related) diseases.

Certain other microorganisms,however, are capable of synthesizingquite unique structures. Elaiomycin,produced by Streptomyces hepaticushas an azoxy structure similar to thatof cycasin, and has weak carcinogenicactivity in rats. Griseofulvin fromPenicillium griseofulvum is useful inthe treatment of fungal skin infections.This compound has induced liver tumors and other liver-specific effectssuch as cirrhosis and protoporphyrinin mice. Streptozotocin, from Streptomyces achromogenes possesses anN-nitrosourea structure, a most unusual type of compound. While thiscompound induces kidney and lungtumors in rats, it is a useful drug intreatment of neoplastic disease. Stillother mycotoxins which may exhibitsome carcinogenicity are luteoskyrin(from P. islandicum) and Actinomycin D (from S. chrysomallus or S.antibioticus ).

Precautions to take

What measures can be taken toprotect against some of these naturallyoccurring carcinogens? As an example, aflatoxin can be considered.

Naturally occurring carcinogensOrgan

Species developingToxin Source affected tumors

Actinomycin D Streptomyces chryso(T18/1us Mouse Localor S. antibioticus Rat reaction

Aflatoxin B1 Aspergillus f1avus from Man? Livermoldy grains

Aflatoxin B2 Monkey LiverAflatoxin G1 Mouse Liver

(infant)Aflatoxin G2 Rainbow Liver

troutRat Liver

Asarone Calamus root Rat Intestine

Cycasin Cycads Guinea pig IntestineMouse KidneyRat Liver

Elaiomycin Streptomyces hepaticus Rat Various sites

Ergot (crude) Claviceps purpurea Rat Fibrousfungus on rye tissue

Estragole Oil of tarragon Mouse Liver

Ethyl carbamate Fermented products Mouse Lung

Griseofulvin Penicillium griseofulvum Mouse Liver

Luteoskyrin Penicillium islandicum Mouse LiverRat

Macrozamin Encephalartos and Rat Kidneyzamia plants Liver

Lung

N-Methyl-N-formyl- False morel Mouse Liverhydrazine Lung

Nitrosamines Tobacco Rat Liver

Petastenine Coltsfoot plant Rat Liver

Pyrrolizidine Senecio plants Rat Liveralkaloids

Safrole Natural plant oils Mouse LiverRat

Sterigmatocystin Aspergillus versicolor Mouse LiverRat

Streptozotocin Streptomyces achromo- Rat Kidneygenes Lung

Unknown Bracken fern Cattle BladderMouse IntestineRat Lung

small quantities of many toxins fairlywell, especially if the nutritionalquality of the diet is adequate. Furthermore, repair enzymes are availableto handle isolated damage,

Except for aflatoxin and cycasin,many of the naturally occurring carcinogens are relatively weak, Also,many of our foodstuffs contain substances that can inhibit the action ofthese carcinogens, Vegetables such asbrussels sprouts, alfalfa, and cabbagecontain certain indole derivatives thatprotect against carcinogens,

Thus, a moderate, nutritionallyadequate diet affords protectionagainst some toxins, In addition, theavoidance of obviously deleteriousmaterials such as tobacco or moldyfoods is advantageous in protecting oneagainst naturally occurring carcinogens,

Additional readingSunderman, F. W., Jr., Carcinogenic effccts of metals, Fed. Proc.. 37, 40( 1978).

Wogan, G. N., Naturally occurring carcinogens, In The Physiopathology ofCancer, Vol. 1: Biology and Biochemistry,Karger. Basel, 1974, p 649.

Miller, J. A" Miller, E. C, Carcinogensoccurring naturally in foods, Fed. Proc..35,1316 (1976).

Toth, B., Nagel, D., Tumors induced inmice by N-methyl-N-formylhydrazine ofthe false morel Cyromitra esculema. J.Nat. Cancer Inst" 60,201 (1978).

Schmeltz, I., Hoffmann, D.. Nitrogencontaining compounds in tobacco and tobacco smoke, Chem. Rev.. 77, 295( 1977),

Ough. C S., Ethylcarbamate in fermentedbeverages and foods: Naturally oceurringcthylcarbamatc, J. Agric. Food Chern., 24,233 (1976),

Brekke, O. L. Sinnhubcr. R. 0., Peplinski,A. J.. Wales. J. H .. Putnam, G. B.• Lee, D..I., Cieglcr, A., Anatoxin in corn: Ammoniainactivation and bioassay with rainbowIroul. Appl. Environ. Microbiol .. 34, 34( 1977).

Growth of the fungus on seed crops canbe inhibited by proper harvesting. bypreventing insect damage, by avoidingdamage to the kernels and by ensuringproper d ryi ng and stori ng.

Many simple compounds such asp-aminobenzoic acid: potassium sulfite; potassium fluoride: and acetic,eitric and lactic acids inhibit thegrowth of the I'ungus or production ofthe toxin. Furthermore, an extensivesearch by the Southern Regional Research Laboratory has shown that aflatoxin B 1 can be inactivated by various treatments.

A promising one involves treatmentwith ammonia (at two or three atmospheres of pressure) to cleave the lactone ring of aflatoxin with the loss of

onc carbon. Further degradation canoccur with complete loss of two ringsin the aflatoxin molecule. Compoundsof this type are not carcinogenic whentested under conditions where aflatoxin B 1 is active. Furthermore. theammonia treatment does not seem toaffect the protein level of treated peanut meal, for example. Thus the process offers a means to salvage large lotsof contaminated oil seeds for animalfeed.

Although there are many naturallyoccurring carcinogens in the environment-except for tobacco and aflatoxin-data relating these substancesto cancer in people are lacking. However, the normal mammalian detoxification systems can usually handle

Elizabeth K, Weisburger is chief LaboralOry ofCarcinogen Metabolism. DivisionofCancer Calise and Prerention. NationalCancer Institute. Dr. Weisbllrger is aconsliitalll to the National Academy ofSciences/National Research COlincil, andis assistalll editor-in-chiefof the JOllrnal0/ fhe National Cancer IllSt;fllte.

Coordinated by LRE


Ralph A. ZingaroTexas A& M University

College Station, Tex, 77843

"In general, a very minor andprobably insignificant redistributionof nuorine in the environment occursdue to industrialization, burning ofcoal, fertilization, nuoridation of watersupplies, and so on, but this does notconstitute in any way a danger toman." This was the conclusion presented by Leon Singer at the Symposium on Some Recent Developments

in the Bio- and EnvironmentalChemistry of Some Trace Elements.The symposium was scheduled as partof the 34th Southwest RegionalMeeting of the American ChemicalSociety (ACS), held in Corpus Christi,Tex., November 29-December I,1978.

In addition to Dr. Singer's presentation on nuorine, other speakers included Howard Ganther, University ofWisconsin (selenium), Fred Brinckman, the National Bureau of Standards (N BS, tin), Arthur Martell,Texas A&M University (transition

metals), and Kurt Irgolic and RalphZingaro (arsenic).

The most obvious message toemerge from this meeting was the needfor accurate and reliable analyticaltechniques. Hence, the speakers directed a considerable portion of theirpresentations to recent developmentsin their laboratories, which involvedanalytical procedures. The symposiumwas structured primarily to inform andeducate the audience on the currentstatus of the environmental and biochemical status of these trace clements. The emphasis was not placed on

282 Environmental Science & Technology 0013-936XI79/0913-0282$01.00/0 © 1979 American Chemical Society

the highly technical aspects of the research by the particular investigators.

Fluorine

This element, in the form of thefluoride, is most ubiquitous in nature.In some minerals, such as calciumapatites, and in magnesium and irondeposits, the concentrations are high.In soft animal tissues, body fluids andplant materials, fluoride is present invery low concentrations, less than 0.2ppm.

A very minor and probably insignificant redistribution of fluoride hasoccurred in the environment, becauseof the industrialization of our nation.This is attributed principally to theproduction of metals for a variety ofuses, and to the burning of coal forenergy. A lesser redistribution can beattributed to the extensive fluoridationof municipal water supplies, whichoften requires, for good oral health, theaddition of substantial amounts offluoride to drinking water. Suchdrinking water contains less fluoridethan optimum (1.0 ppm).

Other sources arc the use of fluoride-containing substances, such astoothpastes and mouth rinses, which,in part, end up in the sewage system fordisposal; the extensive use of phosphatefertilizers for improved plant growth;the use of mineral mixes as feed supplements for animals; and the recycling of waste food products, such asbone, in the food chain. Because fluoride has as affinity for bone, it is obvious that products containing bonewill, in most instances, increase thefluoride intake. The foregoing listssome of the major reasons why a certain redistribution of fluoride in theenvironment has taken place.

Assertions have been made that thefluoride content of liquid effluent discharged into streams from sewageplants might have a deleterious effecton fish and other life. Thus, Singer,along with W. D. Armstrong, felt thatit was important to determine the fateof fluoride in a sewage treatment plant.After all, a large fraction of fluoridatedwater, which contains approximatelyone ppm of fluoride, along with thefluoride in the rain and melted snowthat enters storm sewers, ultimatelyreaches the sanitary sewage system.

For instance, the liquid effluentfrom the sewage plant in MinneapoIis-St. Paul, Minn., serving the TwinCities, contained 1.21 ppm fluoride,which was higher than the 1.0 ppmwhich occurred in the fluoridatedwater supply of the communities.Discharge of the effluent into theMississippi River did not greatly in-

crease the fluoride content of the riverwater. The semi-solid waste from thesewage treatment, which containedover 200 parts per million (ppm) offluoride, released little fluoride to theatmosphere when burned. However,rain and snow were found to containdetectable quantities of fluoride whichdid contribute to the fluoride contentof sewage. This contaminant fluorideobviously came from environmentalsources.

SeleniumSome dramatic recent developments

have contributed greatly to the understanding of the physiological role ofselenium at the molecular level. Thenature of these recent discoveries wasdescribed by Howard Ganther of theDepartment of Nutritional Sciences,University of Wisconsin.

The element attracted considerableattention during the 1930's, when itwas discovered to be a natural toxicant. These early studies dealt primarily with the poisoning of livestockin South Dakota and adjacent areas,when animals fed on selenium accumulator plants. However, in the1950's, pioneering studies, attributedprimarily to the late Klaus Schwartz,identified selenium as an essentialtrace element for animals.

A biochemical role for the elementwas not established until the early1970's, as a result of studies on erythrocyte glutathione peroxidase, whichculminated in its identification as aselenium-containing protein in 1973.Two additional microbial proteinscontaining stoichiometric amounts ofselenium have also been isolated; theyare protein A of the glycine reductasecomplex, and formate dehydrogenase.Although these proteins were knownbefore 1970, they had not been recognized as selenoproteins.

Glutathione peroxidase uses glutathione to reduce hydrogen peroxideand organic hydroperoxides to lessharmful products. Thus, a broad rolefor this enzyme in protecting tissuesfrom oxidative damage is apparent,and its close nutritional interrelationships with vitamin E, sulfur aminoacids, and antioxidants are understandable.

Glutathione peroxidase could alsohave an important function in themetabolism of hydroperoxides that arenormal intermediates in biosyntheticreactions, such as in the synthesis ofvarious prostaglandin derivatives fromarachidonic acid. In view of the greatbiological activity of prostaglandinsand related compounds, a role for selenium in such processes might providea different approach to interpreting the

role of selenium in nutritional diseasesbeyond the classic, but poorly focusedtheory of a role in controlling lipidperoxidation leading to pathologicalchanges.

It is also important to note thattissues contain an additional glutathione peroxidase which acts on organic hydroperoxides (but not hydrogen peroxide), and does not containselenium. This peroxidase activity hasbeen shown to be identical with theglutathione transferases-enzymeswell known for their role in catalyzingthe conjugation of glutathione withvarious organic compounds to formthio ethers and other products.

Selenocysteine, the selenium analogof cysteine, has been reported to represent the chemical form of seleniumin the reduced selenoprotein of theglycine reductase complex, and inglutathione peroxidase. The evidenceis largely based on co-chromatographyof alkylated derivatives, and has notyet been confirmed through use ofmore conclusive techniques, such asmass spectrometry.

The close relationship which existsbetween selenium biochemistry andsulfur biochemistry is further apparentin a glutathione-dependent pathwayfor reduction of selenium to hydrogenselenide (H 2Se). This pathway, beginning with inorganic salts such assodium selenite, proceeds by a reactionwith glutathione to form 2-selena,1,3-dithia derivatives, commonly referred to as "selenotrisulfide"(GSSeSG). This in turn, is reducedenzymatically by NADPH and glutathione reductase in two steps, forming first the labile selenopersulfide,GSSeH, and followed by further reduction to H,Se. The formation ofH2Se and other selenols may explainwhy heavy metals and seleniumsometimes accumulate together athigh levels in the liver, apparently in anontoxic form, as in certain marinemammals, or in cats fed tuna.

The dietary selenium intake formost Americans is probably adequate,and no cases of Se deficiency in humans are recorded. However, certainhighly purified diets used therapeutically, as in intravenous feeding, arebased on pure amino acids rather thanproteins or protein hydrolyzates. Thesediets are exceedingly low in Se, andcould conceivably cause problems ifthey are used as the sole source of nutrients over extended periods of time.

TinMan has been involved with tin

since ancient times. Tin bronzes wereexploited by ancient Sumerians fortools and weapons 2000 years before


FIGURE 1

How biological and chemical transformations formmethylmetal(loid)s

Organotin uses

It is important to recognize thatorganotins offer great potential forspecific biological applications in thematerials preservation, agriculture,and health fields. Their biocidalproperties have been long known: toxicresponses of microbiota, insects, oranimals are well documented. For agiven R group, mammalian toxicityincreases in the order RSn3+ <R2Sn2+ < R4Sn - R]Sn+, with tetraorganotins' toxicity dependentmainly upon rates of metabolic conversion to R3Sn+.

In contrast, for a given structure,such as R]Sn+, animals show decreasing toxic responses to R = ethyl> methyl propyl> butyl> phenyl,although dosages are found to bespecies-dependent. Also, iso-alkyl derivatives are more lethal than theirnormal-alkyl isomers. Nearly an inverse order of lethality for R3Sn+agents is observed for microbiota, suchas fungi and bacteria.

Typically, trace amounts of theseorganotins dissolved in aqueous salinecellular media process ionic properties.Their toxicities are relatively unaffected by presence of different labileanionic ligands, such as chloride orhydroxide. In addition, the aquaticorganotins [R nSn(OH 2)",)(4-n l+, arehighly solvated (n + m = 5 or 6) andinvolatile, and they show strong lipophilic properties.

Dramatic recent successes in synthetic organotin chemistry imply thata very great range of highly organism-specific biological applicationscould be available through appropriatetailoring of steric and constitutionalfeatures of commercial organotinbiocides. Evidence to date also suggeststhat residues from such applicationsshould also be localized in use, andnon-refractory to eventual Sn-C cleavages, in order to provide environmentally compatible materials. Molecular design and use of specificallyactive organotin biocides are presentlylimited by several factors, such as:

• development of storage and release matrices for controlled release oforganotin biocides into environmentalmedia at very low concentrations

• development of ultra-trace (ppbor less) speciation techniques per-

(Figure I). The studies of Schwarz in1970 gave researchers a clue to theessentiality of tin in mammalian metabolism. Other clues to possible noralor animal uptake pathways involvingbi-elemental synergisms, includingthat between tin and mercury inaquatic plants, have also been discussed.

Watercolumn

o

o

properties as catalysts, polymer stabilizers, and biocides, now find ubiquitous use and worldwide distributionin many important materials. Theseincorporants, usually present in smallconcentrations, can be expected toexhibit some of the tendencies of or·ganotins for ready uptake in plants andanimals, depending upon specificend-uses of these materials, and theirrefractory behavior in the environment. Such trends for both metallurgical and organotins, coupled withheightened awareness of environmental consequences of man's activities, makes this topic timely and challenging.

Underlying changing perceptions oftin's active role in biological processesis the greater overall recognition thatmany heavy metals, hitherto regardedas either toxic or inert, can participatein numerous biotransformations.During the past three decades, arsenic,selenium, tellurium, lead, and thallium, as well as tin, have been implicated in environmental biomethylations, to produce lipophilic or volatilemetabolites. Clearly, a new outline forbiogeochemical cycles of so-called"non-essential" elements is emerging

I 9/

MemE + MeGI "

o

o

Particulates

Gases oo

oo

For example, M might be Sn(IV), and E might be Hg(II), or other metals, such asPb(IV), and TI(III), respectively.

lipidsHydrocarbonsHalocarbons M-complexes

. Detritus.---------------------------------6------------------0---.~-.--..-----

Bacteria / !/" /Cr--r Men., M+ + MeC;

\ GI-'\

"-..... MenM+ MemE+

Egyptian pewterers were busily fab·ricating household objects of this metalin 1500 B.C. The metal is widely dispersed and diluted in the lithosphere,typically about 2-10 ppm in rocks andsoils. Local accretions of its familiaroxide ores provided then, as now, access to the ductile, low-melting metal,by simple thermal reduction techniques.

In the United States, where theper-capita consumption of beveragecans exceeds 190/year, tin-plate isused for foodstuff preservation in overhalf of the cans produced. Conventional experience suggests that tin in itsinsoluble or metallic forms, such asthat found in rocks or food cans, offersvery limited bioavailability, and thatsuch widespread direct human contactresults in little adverse uptake. However, it is currently recognized thaturban sewage sludges-representinggross "indicators" of heavy metalpollution and biocycling-containunusually high tin concentrations(about 111-492 ppm, dry weight).Information is lacking on the chemicalforms, or bioavailability, of these anthropogenic sources.

Organotins displaying many useful


Highperformance

liquidchromatography

pump

Drain

R. Braman at the University of SouthFlorida, which describes widespreaddistribution of methyltins at extremelylow concentrations in diverse environmental media. Braman finds thatthe former range about 2.5-13.5 nglLin seawater to rain water, and compriseslightly less than half of the total tindetected. These observations are veryimportant for assessing the overallbiogeochemical tin cycle, particularlywith the goal of establishing baselinedata permitting differentiation between natural and anthropogenicfluxes.

Perhaps, the thrust of environmentalchemistry in the Seventies might besummarized as a combination of advances in trace element detection with"clean room" protocols. These accomplishments would go hand-in-handwith a broadening vista of aqueousorganometallic chemistry coupled withmicrobiology, to focus on questions ofbioavailability, transformations, andflux of industrial metals. A centralproblem remains to ensure that a database of sufficient scope and reliabilityemerges to allow examination of thoseenvironmental models which will dif-

Atomicabsorption

Analog-digitalpulse height -

area

HGA

,,,,-+-

Drain

FIGURE 2

Determining bioactive organometallic species

....-'-El~ {~r-----,Sampleinjection

metal ions interacting both biologicallyand abiotically to generate organometallic metabolites cannot be regarded as an unusual process, althoughso far, only methylation appears to beinvolved. Several exo-cellular metabolites capable of methylating metaland metalloid ions have been suggested, but the best known is methylcobalamin (a vitamin B-12 derivative),in which the methylcobalt bond readilymethylates a number of main-groupand transition metal ions, including tin.The ubiquity of such microbiologicalprocesses in the biosphere suggests thatunder some circumstances, even inorganic or metallurgical forms of tin maybe available to a methylation "pool,"for example, through solubilization bybiogenic methylcorrinoids.

It would appear equally likely thatanthropogenic organotins would alsofind entry into this "pool," althoughmany abiotic degradative reactionsmight intervene. More detailed experiments are needed to reveal, convincingly, whether or not biomethylation of tin is an important environmental pathway.

Bri nckman reported on the work of

Experiments at NBS

Brinckman described some of theseactivities at the National Bureau ofStandards (N BS) laboratories. Studiesthere have focused on developing speciation methods (Figure 2) for tracebioactive organometallic molecules inenvironmental media; establishing adescriptive aquatic organometallicchemistry with emphasis on reactionmechanisms; and providing a qualitative survey of the extent and kinds ofmetal transformations occurring inmicrobiota, which involve organometallic species.

Several years ago, these laboratoriesreported on the biomethylation of Sn(IV) by a prevalent marine species ofPseudomonas, which had earlier beenfound to reduce mercuric ion, exclusively, to gaseous Hgo. In separatestudies, this group observed that thehydrated trimethyltin cation was capable of abiotically transferring CH 3to aqueous Hg2+ at a rate competitivewith biomethylation of tin. These observations led to critical experimentsin which it was shown that Pseudomonas sp., metabolizing under dualstress of both SnH and Hg2+, yieldednot only HgO, but CH 3Hg+ as well.This reaction required intermediacy ofthe biogenic CH 3-Sn metabolite.

The prospect of several bioactive

mitting accurate definition of amountsand molecular features of releasedagents

• development of bioassay techniques, in order to provide options forimproved molecular tailoring and increased environmental regulation.

Much progress has been made,lately, by chemically incorporatingselected trialkyltin moieties into bothorganic and inorganic polymers.Controlled release systems are therebyproduced, which can be blended intosurface coatings, to give prolongedresistance to marine fouling or biodeterioration.

These release systems can also act asspecific long-term inhibitors to reproduction of aquatic snails which hostthe dread Schistosomiasis diseasewhich afflicts perhaps 350 millionpeople in the Earth's equatorial belt.The latter application represents a verycheap and simple mode of field application in those areas of the world incapable of the primary science, butgreatly in need of the product. Futureadvances are expected to result fromnew understanding of the coordinationchemistry of di- and trialkyltin functions of biologically critical sites, particularly those protein or enzymecomponents bearing nitrogen or sulfurdonor atoms.


Detection. This apparatus is being used to determine arsenic compounds

ferentiate between planetary andman-made stresses and alterations ofbioactive metals. This is especially trueof tin, because of its wide distributionin nature upon which man's technologyplaces ever-increasing burdens.

ArsenicThe conversion of inorganic and

certain organic arsenic compounds byorganisms, such as Pseudomonasbrevicaule and methanobacterium. toorganic arsines of the general formulaR nAsH3_n (n = 1, 2, 3) is now a wellestablished fact. Although some ofthese conversions have been known foralmost one hundred years, detailedmechanisms for these reactions are stillnot available.

Arsenic has a complicated chemistry. It forms a great variety of organicand inorganic compounds whose effects on living organisms vary greatly.It is, therefore, not surprising that organic arsenic compounds, other thansimple arsines, have been detected invarious organisms. For example,Lunde found organic arsenic derivatives in the lipids of marine and limnetic organisms.

Acid hydrolysis of the arsenic-containing lipid fractions produced watersoluble, organic arsenic compounds.This is documented by the isolation ofarsenobetaine from rock lobsters, asreported in 1977. These findingsclearly demonstrate that transformations, much more complex than simplemethylation, are undergone by arseniccompounds in biological systems.

In order to identify the organic arsenic compounds, which are known tooccur in many marine organisms, the

marine alga Tetraselmis chuii, a greenflagellate (Chlorophyta) was grown ona large scale in "Instant Ocean"@medium, in the presence of I0 ppm As(arsenate). Extraction of the harvestedcells with chloroform/methanol revealed that arsenic occurs both in theextract and in the extraction residue.The arsenic in the extraction residue,together with proteinaceous water, wasdissolved in water. Addition of methanol precipitated an arsenic-proteincomplex. Exchange with 74As-arsenicwith non-radioactive arsenate occurredonly after an excess of arsenate hadbeen added. The nature of the arsenic-protein complex is not known atthis time.

The lipid-containing chloroformlayer was freed from green pigmentsby chromatography. A phospholipidfraction with an arsenic content of0.5%, which contained two arseniccompounds, was isolated.

A new techniqueThe detection, identification, and

quantification of these organic arseniccompounds are being greatly simplified by a new analytical techniquewhich combines high-pressure liquidchromatography (HPLC) with a Hitachi-Graphite Furnace-ZeemanAtomic Absorption Spectrophotometer as an element-specific detector. Thetechnique, being developed at TexasA&M University, does not require achemical modification of the arseniccompounds for detection and quantification. The excellent resolving powerof H PLC, the wide choices in columnmaterials and mobile phases, and thegreat sensitivity of the Zeeman atomic

absorption detector produce a signalonly when an arsenic compound iseluted.

The fractions containing arseniccompounds need not be pure for theirdetection. They may contain other,arsenic-free materials, which in mostcases will not affect the performanceof the arsenic-specific detector. Suchan analysis and detection system isideal for the speciation of arseniccompounds, and other compoundscontaining elements that can be detected by atomic absorption spectrometry.

The HPLC-graphite furnace atomicabsorption spectrophotometer systemhas been automated through the development of an electronic interface.This system has been used to detectorganic arsenic compounds in phospholipids, to effect the separation ofinorganic arsenic, arsenobetaine andarsenocholine, and to detect, simultaneously, arsenate, arsenite, methylarsonic acid and dimethylarsinic acid.

Transition metalsArthur Martell, who has a long and

distinguished career in transition metalchemistry, addressed the subject ofessential transition metals. He pointedout that all living systems require theelements H, C, N, 0, Mg, P, S, Ca,Na, K, CI, Mn, Fe, Cu, Zn, and Mo.The number of species requiring theremainder of the elements thought tobe essential ranges widely; however,barium, for example, has been shownto be required only by one species (therhizopod Zenophyophora). The firsteleven elements referred to are presentin living systems in relatively largequantities, and are designated as majorelements. The remainder come underthe category of trace elements, withiron representing a borderline case.

The recent demonstration of theessentiality of nickel means that all ofthe first-row transition metals, exceptfor Ti, are considered essential. Thelatter has been found to be stimulatory,atld its essential nature may possibly bedemonstrated in the future. The closelyrelated non-transition metals Zn andCd, as well as Mo, a second-row transition metal, are also essential tracemetals.

Since the nutritional requirement ofan essential metal must be based onvital biological functions, demonstration of trace metal requirementsshould be followed up by studies of themolecular basis for biological activity.The functions of many transitionmetals in biological systems have beenknown for some time, and are well established; for example, the activationof various enzymes by Mo, Fe, Co, Cu,


TABLE 1

Biological functions and toxicities of essential trace metals

a Not a transition metal. C =carcinogenic; B =blocking of essential enzymes; I = interference withregulatory mechanism; vital organ or metabolic function; 0 = interaction with DNA, RNA polymerase,and so on; M = interference with membrane function.

element is beneficial or essential forbiological function at low levels andcarcinogenic at higher concentration,is a phenomenon common to manyother (non-metal) carcinogens.

Such behavior strongly supports thethreshold concept of chemical carcinogenic activity, and directly countersthe "single-event" or "one-hit" hypothesis that has been translated intolaw, in the form of the Delaneyamendment to the Food and Drug Act.The Delaney amendment continues tobe greatly controversial.

Nitrilotriacetic acid (NTA) is another example of a compound of extremely low toxicity, which seems tocause tumors when massive doses areadministered to experimental animalsover long periods of time under conditions such that essential physiological functions are extensively altered.One of the earlier concerns about thisligand and its potential large-scale usein detergents was that it would find itsway through sewage efnuents intodrinking water, and rearrange tracemetal levels in the environment and inthe body. Although its use as a detergent builder has been prevented by aFederally-sponsored "voluntary" banin the U.S., it is used extensively forthat purpose in Canada and elsewhere,so that evaluation of its effect on theenvironment is now possible.

As it turns out, the high biodegradability of NTA lowers its level to a fewparts per billion in some drinkingwater, and to undetectable levels inother waters (such as Lake Ontario).

Ralph A. Zingaro is prOfessor ofChemistryof Texas A&M University and remainsactive in all aspects of selenium and arsenic chemistry, an area in which he hasbeen involvedfor 25 years. He is a memberof the subcommittee on arsenic of theCommittee on Medical and Biologic Effects of Environmental Pollutants of theNational Academy ofSciences.

Coordinated by JJ

Additional readingOccurrence and Fate of Organometals andOrganomelalloids in the Environment,American Chemical Society SymposiumSeries 82, Washington, D.C. (1978).Proceedings of the 5th InternationalSymposium on Controlled Release ofBioactive Materials, Nat. Bur. Stand.,Gaithersburg, Md., August, 1978.Trace Element Metabolism in Animals,W. R. Hoekstra, J. W. SUllie, H. E. Ganther, and W. Mertz, Eds., University ParkPress, Baltimore, Md., 1974.Addison, A. W" Cullen, W. R., Dolphin,D., and James, B. R., Biological Aspectsof Inorganic Chemistry, Wiley-Interscience, New York, N.Y., 1977.

Model calculations of NTA speciationin natural waters and in test-animalfeed experiments have been done. Theresults show that NTA is alwayspresent in the environment in the formof its metal chelates..

At normal environmental levels, asin Canadian waters, TA occursmainly as chelates of strongly coordinating transition metals. At abnormally higher (I OOX) levels it is primarily bound to alkaline earth ions. Inanimal feeding experiments, however,competition with phosphates and natural chelating ligands in the feed resultin nearly all the NTA being in the freestate (alkali metal salts). Since theproperties and biological effects of ligands are highly dependent on themetal ions to which they are bound,these results demonstrate the futilityof testing environmental NTA chelatesfor carcinogenicity by the animalfeeding experiments of the type generallyemployed.

AcknowledgmentThe financial assistance in support of

this Symposium furnished by the Magcobar Division; Dresser Industries, Houston,Texas, is gratefully acknowledged.

C,I

I,BC,O,I,B,M

C,O,IC,IO,I,M

I,BC,II,DC,I

Toxic leveleffectsBiological function

(Oxidation-reduction enzyme)(Glucose tolerance factor)Pyruvate oxidaseXanthine oxidaseCy1ochrome cFerridoxinO2 transport and storageVitamin B'2 coenzymeUreasePhenol oxidaseCy1ochrome oxidaseAlkaline phosphatase

. CarboxypeptidaseCarbonic anhydraseAldolaseAlcohol dehydrogenaseXanthine oxidase

CoNiCu

VCrMnFe

Transitionmetal

and Zn, and the role of Fe in oxygentransport and electron transfer.

When it's good or badExamples of the biological functions

of essential transition metals, and indications of their toxic effects are givenin Table I. Specific enzyme systemsare cited in cases in which metalloenzymes and metal-activated enzymesystems have been identified. In thecase of V and Cr, enzyme functionshave been reported, but specific enzymes have yet to be isolated. Cd isfrequently listed as essential, but hasnot yet been assigned an essentialfunction.

Of the metals listed in Table I, Cr,Zn, and Cu display the widest separations between beneficial and toxiclevels. In the case of Mn, there are efficient detoxification mechanismswhich prevent toxic accumulations. Avery low spread between toxic andbeneficial dosages is observed for Cdand V. Ni is extremely toxic and carcinogenic at high levels, but is renderedrelatively harmless in the diet becauseof low absorption through the gut, asthe result of the lack of efficienttransport mechanisms.

Threshold YS. "one-hit"Of the ten essential metals listed in

Table I, six are known carcinogenswhen present in mammalian systemsin sufficiently large amounts. In somecases, such as Cd and Ni, only relatively small doses are carcinogenic.This dual behavior, in which a trace


Samplingand analysis ofsynthetic fuel processes

Obtaining meaningful results is not a routine procedure andcannot be approached casually. It requires a professional

staffcapable ofmaking in-field decisions to adjust toprocess changes and unanticipated problems

P. S. DzierlengaF. G. MesichR. A. MageeRadian Corp.

McLean. Va. 22102

Synthetic fuels based on coal gasification and liquefaction technologyare prime candidates for providingenvironmentally acceptable uses ofcoal. Designing and demonstrating thetechnology, however, does require acomplete understanding of the natureof process and emission streams in thecontext of available environmentalcontrol technology.

For this emerging industry, thispresents both opportunities and problems. Since few commercial plants arein existence, the correction of historicalenvironmental errors is not required.The existence of pilot and small-scaleunits presents the opportunity to buildin environmental factors at the development stage while scaling environmental data from a small unit to acommercial plant.

There are many approaches to acquiring environmental data dependingon the end use of the information. TheEPA uses a staged approach aimedparticularly at emissions. Alternateapproaches concentrate on the processstreams to provide data for design oftreatment processes. The needs of thetoxicologist are different from the design engineers. This feature relates theapproach that Radian Corporationuses to design test plans for any speci fic end use.

Radian Corporation has performeda number of environmental samplingprojects on synthetic fuel processes and

288 Environmental Science & Technology 0013-936X/79/0913-0288$Ol.00/0 © 1979 American Chemical Society

has written sampling guideline documents for both the EnvironmentalProtection Agency and Department ofEnergy. Sampling projects have included the sampling of the CO2 Acceptor Pilot Plant; the Hanna In-SituGasification Project; and Lurgi,Wellman-Galusha, Chapman (Wilputte) and Foster Wheeler/Stoicgasifiers and attendant environmentalcontrols. All experience to date hasshown that sampling a synthetic fuelprocess and obtaining meaningful results is not a routine procedure andcannot be approached casually.

Radian experience has been that themajor requirements for a successfulsampling effort are: careful planningprior to the test effort, including thedevelopment of a good sampling plan,and the use of an experienced, professional staff capable of efficiently executing the test plan and making infield decisions to adjust to processchanges and unanticipated problems.

Planning prior to the test effort involves determining the scope of theproposed sampling effort, analyzingthe process to be sampled, selectingsampling and analytical procedures,and designating the program dataevaluation requirements. This planning culminates with the developmentof a test plan for the environmentalsampling effort.

Project scopeAn environmental sampling pro

gram may be initiated to achieve all orpart of the following objectives:

o to define plant effluentso to verify process compliance with

environmental regulationso to verify control technology per

formanceo to characterize the process or a

segment of the process.Project complexity varies with program objectives.

The first step in determining projectscope is to define the objectives of thespecific sampling effort. With the objectives established, a preliminary estimate is made of the requirements toachieve program goals, plant streamsto be sampled, parameters to be measured, sets of plant conditions to beanalyzed, and manpower and equipment requirements. These requirements are then reconciled with program time and budget constraints.

Since there are inevitable trade-offsthat occur between program goals andbudget, it is recommended that a staffstatistician be a part of the projectteam. A good experimental designshould maximize the useful information resulting from any sampling effortand enhance the overall cost effec-

tiveness of the program. This inputduring the period when project goalsare reassessed is very helpful.

NextA process analysis defines the pro

cess segments (equipment and unitoperations) of interest to the characterization effort. This analysis identifies the streams to sample, componentsof interest, process conditions at whichtests will be conducted, process dataroutinely monitored, and process datawhich must be obtained in conjunctionwith the environmental sampling. Thisstep should include the performance ofheat and mass balances for each process segment of interest, a tabulationof available physical and chemicaldata on effluent and process streams,and a determination of the residencetimes of the major process vessels.

An important part of the processanalysis is an on-site survcy, whichshould be conductcd by members ofthe sampling team in conjunction withthe plant operating supervisor(s). Thepurpose of the survey is to relate theobjectives of the environmental testeffort to the actual equipment in thefield. Such a survey provides the testcrew with a better working understanding of the process and serves tominimize the number of "surprises"that may occur once the crew andequipment begin the environmentaltesting.

Sampling a synthetic fuelprocess is complicated by

these factors:

• The physical and chemicalcharacteristics of synthetic fuelstreams pose difficult samplingproblems. [Gas streams are often athigh temperatures and high pressure, and contain particulates, tarsand oils. Liquid sampling may becomplicated by the presence of twophases, solids in the liquid stream,or dissolved gases under pressure.Solids may be stratified makingrepresentative sampling difficult.]

o The processes are being developed and many opportunities formechanical malfunction and process upset exist, and do occur.-. It is often required to collect

data from a pilot-plant or smallscale operation for application to alarge-size design. In such cases,extra care must be taken in testplant design to allow correlationand scale-up of the pilot-plantdata.

During this survey, partIcular attention should be paid to:

o location and physical layout ofthe process(es)

• types of vessels and equipmento types and location of pipingo location and origin of input

streamso location and destination of prod

uct, by-product, effluent streams andemissions

o types and location of process instrumentation

• location and availability of sampling points.

Sampling and analytical proceduresare based on program objectives(scope) and results of the processanalysis and on-site survey. The basicsample-selection problem is determining how best to obtain a smallfraction of material that is statistically

Steps in the development ofthe test plan include:

o Definition of a processstream-analytical parameter matrixfor each set of operating conditionsat which samples will be taken.Table 2 illustrates a processstream-analytical parameter matrixfor sampling points and analyticalparameters for the C02 Acceptorgas streams.

o Definition of process operatingparameters to be monitored prior toand during execution of the testplant. Key process operating parameters should be monitored priorto test plan execution to establish abaseline for determining steadystate conditions and to ensure thatno prior process upset will innuencetest results. .

• Identification of stream-analytical parameter combinations forwhich data from other sources(plant records and operating personnel) will be adequate.

• Designation of sampling andanalytical techniques.

• Determination of samplingfrequency and timing based onsampling method and data evaluation requirements.

o Designation of a quality control procedures for the sampling testplan.

o Preparation of a test schedulebased on the· plant operatingschedule and the sampling andanalysis manpower/equipment requi rements.


TABLE 1 .. .~

• ComponentS of Interest• Requirements for accuracy

• Limitation of analytical techniques

• Stream physical conditions• Chemical characteristics of streams

• Time sequence sampling to determine variability ofparameters

• Sample stability• Physical arrangement of piping and ducting

• Safety considerations• Time. uil)f!!!!nt. cQstlimitations

• Compatibility wi1h sampling procedures• Expected concentration level and required detection

limit

• Presence of Interfering species• Accuracy and precision requirements

• Requirements of the established quality controlprogram

• Time. equipment. and cost limitations

. .: ......._...-- .-P..• ..- Yr_...... .... -17_ .... co. co No 00 No HCH HoS so" NO, CSo cos H:zO - baM S AI C. P. IIg P K SINon _"

CoaIlJ'1ndlng and x x x x x x x x x xdrying vent

Coal preMater X X X X X X X X X X Xventdo-..amoI~

Coal preMater x x x x x x x x x xvent upslreamoI~

Regenerator -x x x x

gas ventheader~tor_

X X X X X X X X X X X X X X X X X X X X X X X X X Xgasdownstream0' cyclones~or X X X X

oveltleedQuenched X X X X X X X X X X X X X X X X X X

regetWlltorflue gas

Gases dissolved XIn regeneratorquenchwaler

GlISIfier X x x xoveltleed

PI'oducI gas X X X X X X X X X X X X X X X X X X X X X X X X X Xdo-..amof externalcyclone

Quenched X X X X X X X X X X X X X X X X X X X X X X X X X Xproduct gas

PI'oducI gas X X X X X X X X X X X X xdissolved inquenchwaler

Recycle flue gas X

Recycle product Xgas

Gases stripped X X Xfrom gasifierquenchwaler

Gases from X X XlaboratorycIt8ncereactlon

Coal transfer X X X X X X X X X Xcyclone exn

"$b, As, Be. B. CI, Cd. Cr, Cu, F, Pb, LI. Mn, Hg, Mo. Ni, Se, TI, U. V, and Zn.


TABlE 3

v...... orpnIc8 eorIIed on T_ .......8enzeM 500 mg/m3

Tem- TraceE1hytbenzene TraceXylene Trace

representative of the process stream.Of particular importance arc the spatial and temporal variations in streamcomposition and the potential forchanges in composition after removalfrom the stream. Factors which arctaken into account in defining thesetechniques arc summarized in TableI.

Standard sampling procedures areavailable and arc in common usc forcriteria or regulated pollutants in atmospheric or near-atmospheric pressure streams. Other sampling requiresthe adaptation or development of specialized equipment to meet the requirements of a particular process or

5001100225550900

..............,oc

2psig2psig

50 pslgaa

•

..

should typically consist of an in-linefilter. a knock-out pot. an inert filter,a permeation drier, a pump, and a flowmeter. Bags or sample bombs can thenbe used to collect the gases for analysis.Particular problems with gas samplingarc as follows:

High temperatures of gas streamsmay require special construction materials or water, air, or oil-cooledprobes. Materials of construction forsample transport tubes are shown inTable 4. High temperatures also meanthat drastic changes in temperaturesare required for sample handling soreactive species may be quenched.

Temperature of particulate collection defines the split between particulates and condensibles so temperaturemust be carefully chosen if results areto be meaningful. As an example, theEPA Method 5 sampling train collectsentrained particulates with the passageof the gas from the probe to a filtermounted in an oven maintained at 225of. This specification of a collectiontemperature effectively defines whatmaterial is considered to be particulatematter (materials which condenseabove 225 OF).

If the primary test objective is determining the actual stream particulate content rather than verifyingregulatory requirements, then collection at stream conditions is recommended. One approach which inherently requires collection at streamconditions includes mounting theparticulate collection device on the endof the probe extended physically intothe gas stream. This has the addedadvantage of avoiding losses of material to the transport-tube walls. Ifcollection outside the stream is chosen,the sample-transport tube should bedesigned to minimize losses. This isaccomplished primarily by providingsmooth flow contours that avoid protrusions or sharp directional changesin flow and by heating the transporttube to avoid condensation.

Pressurized gas streams pose accessproblems. These streams demand aleak-tight seal. II lubricated packing

Pyrex glassQuartz

TeflonStainless steel (304 or 316 Series)Inconel 600 Series

TABlE 4

Gas samplingSampling of gases is complicated by

high temperatures, high pressures; andtars, oils and condensibles. An exampleof this type of stream is hot product gas(1000-2200 0 F) containing high concentrations of entrained particulates,tars and oils. Table 3 shows the gaseous organic components in the unquenched product gas from the CO2Acceptor pilot plant.

To obtain a representative gassample from a "hot'· stream havinghigh levels of entrained particulates.tars, and oils. a sample pretreatmenttrain must be used. This train shouldremove the particulates, tars, and oilsin a manner such that the concentrations of the gaseous species arc notchanged. Such a pretreatment train

condition. No two plants arc likely tooffer identical problems. By applyingsound judgment. adequate procedurescan be specified in the test plan.

Data evaluation and quality controlThe primary data-evaluation re

quirements to be identified for sampleplan development arc the number ofsamples or tests required to maintainstatistical validity. Based on projectobjectives. time. and budget. an experimental design for the samplingprogram may be defined. Internalquality control checks (routine andrandom) to be made during the dataevaluation procedure can also be defined at this time (Table 2).

Other quality co'ntrol items established prior to sampling and incorporated in the test plan inelude:

" calibration of designated sampling and analytical equipment

• designation of replication duringsampling and analysis

• identification of alternate sampling and analytical methods

• establishment of standard laboratory quality control procedures

• establishment of a chain of responsibility for data generation fromsample collection to evaluation of results.

..12.8%10.8%310 ppm390 ppm

12.7%10.9%

Ethane-e1hyIenea

(aaCaHelTotal hyctOl*1loIl8a

(aseH.1

0rpnIcI eorIIed on XAD-2 .......Tem- 99 ,.gIm

18,.g1m

n»M ~5~/m3

490~/m3

NaphlhaIene 26000 ~/m385OOjlg/m3

2-Me1hy1naphlhalene 14 jlglm387jlg/m3

1~ 14jlg/m363jlg/m3

BIphenyl 7.1 jl9/m381jlglm3

Acenephthene 8.2 jlg/m3

48jl9/m3

Fluor_ 4.6 jl9/m328jlg/m3

PhenantIr_/anthracene 9.2 jlg/m315jlg/m3

Fluoranthene 2.8 ~/m31.4jlglm3

Pyr.- 3.5 jlg/m31.8jlg/m3

DIoctyledlpate 12 ~/m3

"AnalysIs performed using HewtelI-¥ackard5737", uea~a,lh wiIh a IIame lonization det8cIor.eo.- RadIan Corp.

Volume 13. Number 3. March 1979 291

gland similar to valve-steam packingis the most generally applicable option.Figure I illustrates such an interface.The packing gland is mounted on afully opened gate valve or ball valve ofadequate internal diameter (3 inchesis generally adequate) to allow insertion of the probe assembly.

The valve provides closure of the

sampling point when not in use. Pressurized streams also mean that anyparticulates must be collected atstream pressure to avoid losses of material during passage through a pressure-reduction step. Since some probelosses are inevitable, the material mustbe recovered by washing the transporttube with suitable solvent (EPA

Method 5 specifies acetone) followingcompletion of any collection.

Filtration is the most generally applicable technique for collection ofparticulates; however, filters may belimited in synthetic fuel applicationbecause of pluggage from condensibletars and oils, the amount of samplerequired, or the reaction or sorption of

FIGURE 1

Configuration for pressurized gas sampling ...

Mounting flange

/\

... Configurations for liquid sampling

"'Tension adjustmentbo~s

Packinggland

probe+--==~~E-~~--ffi'~g~=dt==~Ball valve Stainless steel

sample bomb

Probe+-=:§~ffi;;~=:lrt~~

Cooling coilsValve

Flow

t High pressure

Flow

t High tempemure,high pressure

Probe-t-...-:===j

Flowmeter

Flow

tPump

Subetmospherlc

Flow

tHigh tempereture,subatmospheric

Pump


gaseous components on the filter medium producing interferences in subsequent analyses. (Studies have shownthat sorption of sulfur dioxide on filtermedia, followed by oxidation is a significant interference in determiningsulfates.) Use of a small electrostaticprecipitator avoids many drawbackspresent in filtration collection.

Sampling of liquidsThe main problems in liquid sample

collection result from pressurizedstreams with dissolved gases, twophase (organics/aqueous) liquids, andslurry or liquid-solid streams. Open tapsampling of high-pressure liquidstreams containing dissolved gases willresult in a loss of dissolved gases afterthe reduction in pressure. If samplescontaining dissolved gases are desired,high-pressure bomb-sampling techniques must be used.

The bomb can either be evacuatedbefore sampling or it may be filledinitially with an inert gas, such as nitrogen or helium. When the lattermethod is used, the initial gas pressuremust be known in order to calculatethe dilution of gases released from thesample on depressurization. The tapsampling of liquids flowing at subatmospheric pressure requires pumpassistance to remove the sample.

The tap sampling of liquid or slurrystreams at high temperature (abovethe liquid boiling point) requires special procedures. The liquid samplemust be cooled to a temperature belowits boiling point before its entry into thesample container or it will flash vaporize. The sample may be cooled bypassage through an air or water jacketsystem before collection. Again, careshould be taken to thoroughly flush allparts of the system before material isretained for analysis.

In most cases, the use of a coolingsystem will cause some loss of sampleintegrity. A loss of material throughdeposition on the cooled wall is unavoidable. In some instances, pluggingof the sample line will result. Theseproblems can be minimized if thesample is cooled just enough to handle,but not below the temperature atwhich sample integrity is lost. Theequipment for sampling liquids atdifferent pressures and temperaturesis shown in Figure 2.

The main problem with two-phaseand slurry streams is stream homogeneity. Liquid streams tend to stratifybecause of different viscosities anddensities. Such liquid streams shouldbe sampled at turbulent locations toensure a well-mixed sample. Downstream from pumps or elbows is apreferred location. [t may be necessary

to have sampling valves installed atpoints where none exist.

Sampling of solidsThe two main problems encountered

in solid sampling are the collection ofa representative sample and the preservation of high-temperature reactivesolids. An inherent problem with solidsampling is that solids do not mix welland tend to separate according to sizeand density. Obtaining a representative sample is further complicated inthat solid handling does not generallycreate points of turbulence from whichsamples can be obtained. Normalsample sources are process storageareas and process conveyors.

Process conveyors are the preferredsources of representative solid materials, because there is less segregationaccording to particle size, and thematerial obtained is often a sample ofsolids actually being used in the process. Generally, the best samples fromconveyors are obtained at the pointwhere the exiting solid material fallsvertically from the conveyor.

Samples from process storage pilesshould be obtained by boring or augering techniques. Boring involves inserting a pipe or thief into the pile fromtop to bottom; the sample in the piperepresents a vertical composite of thepile. This technique cannot be used,however, with wet, coarse-grained, orlump materials. The auger sampler isparticularly suitable for samplingmaterials that are packed too tightlyfor pipe or thief techniques. An augeris like a large drill bit which is turnedinto the pile from the top. When theauger is withdrawn, the sample ispacked in the helical grooves. If necessary to prevent sample spilling, it canbe enclosed in a casing.

High-temperature reactive solidsare another problem. These solids mustbe isolated from air after collection toavoid reaction with moisture or oxygen. Quenching the collected solidsimmediately with an inert gas streamto conditions at which the material canbe handled and analyzed is recommended.

Looking aheadEnvironmentally acceptable syn

thetic fuel technologies may be developed by addressing environmentalfactors through sampling and analysisprograms over the stages of processdevelopment. Although such processcharacterization may be difficult thevalue will be significant.

The acquisition of environmentaldata through a coordinated effortfounded on thorough understanding ofthe process variables and end use of the

data, will result in the most cost effective approach to data collection.

This approach includes making useof the common steps and principlesbriefly described here, whether the endresult is engineering data/health effects data or permit compliance information.These common steps are:

• definition of project objectives• process analysis• selection of sampling and ana

lytical techniques• data evaluation and quality con

trol requirements• test plan development• test plan execution.

Additional readingEnvironmental Characterization PlanDevelopment for a Coal ConversionDemonstration Facility, Radian Corporation, 78-200-151-06-05, DOE ContractEX-76-C-01-2314, May 1978.Environmental Monitoring Handbook forCoal Conversion Facilities, Oak RidgeNational Laboratory, ORN L-5319, May1978.Guidelines for Preparing EnvironmentalTest Plans for Coal Gasification Plants,Radian Corporation, 78-200-143-65, EPAContract 68-02-2147, June 16, 1978.

P. S, Dzierlenga is a senior engineer withRadian and Division Manager of the Radian Washington Regional Office. Mr.Dzierlenga has participated in a variety ofprojects concerning synthetic fuel processing analyses and environmel1lal control technology evaluations includingproviding environmel1lal support servicesto Departmel1l ofEnergy Division ofFossilFuels Processing.

F, G, Mesich (I) is an assistal1l vice president with Radian and is General Managerof the Washington Regional Office. Dr.Mesich is in charge ofall program managemel1l activities on Radian technicalservice contracts.

R, A, Magee (r) is a program manager atRadian. specializing in sampling andanalysis projects. Mr. Magee has had theresponsibility for the sompling and analysis ofa wide variety ofenergy technologies including a number of synthetic fuelprocesses.


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Determination of Heavy-Metal Distribution in Marine Sediments

Edwin S. Pilkington and Leonard J. Warren"

CSIRO Division of Mineral Chemistry, P.O. Box 124, Port Melbourne, Victoria 3207, Australia

• A new method for determining the distribution of heavymetals in near-shore marine sediments has been investigated.The various sediment components were separated into distinct bands in a density gradient formed from the heavy liquidtetrabromoethane. Direct flame and graphite furnace atomicabsorption spectrometry was used to analyze for the low levelsof lead, cadmium, and zinc in the density subfractions. Detailsof the mineralogy and the concentration and distribution ofheavy metals in two selected sediment types are given.

Conventional methods of studying the distribution of traceelements in soils and sediments are based on the selectivedissolution of the sample by a series of reagents of increasingreactivity (J -4). One of the most comprehensive schemes ofthis type (3) involved treating the sediment successively withdistilled water to dissolve soluble and weakly sorbed metal,0.05 M calcium chloride to remove exchangeable metal, 2.5%acetic acid to desorb metal specifically sorbed on organic sites,and so on for a total of nine separate chemical steps.

However, apart from problems of contamination, suchchemical treatments are seldom selective enough to give anunambiguous indication of the metal distribution. Malo (4),for example, found that acetic acid dissolved not only specifically adsorbed metal but also significant amounts of silica andaluminum, presumably from lattice sites. Subramanian (5)observed structural changes in some clay minerals aftertreatment with citrate, bicarbonate, dithionite, and hydrogenperoxide. Agemian and Chau (2) found that about 10% of thetotal aluminum in aquatic sediments was extracted by cold0.5 N hydrochloric acid, a treatment normally presumed todissolve only the complexed, adsorbed, and precipitated heavymetals.

In the present paper another approach is reported in whichthe various sediment components, including the organicmatter, are separated before analysis for heavy metals withoutchemical change. The basis of the method is that the components of a sediment, differing in specific gravity, will separateinto distinct bands in a density gradient in a suitable heavyliquid.

Similar methods have been developed for use in the mineralprocessing industry (6) and for characterizing soil clays (7),but their potential for environmental analysis has only recently been realized (8). Using density-gradient mineralsegregation in a zonal rotor, Francis and Brinkley (8) detectedpreferential adsorption of radioactive cesium on the micaceouscomponent of a freshwater sediment.

We have found that the density-gradient technique can beused to separate the main mineral species in a near-shore

sediment and that the total lead, cadmium, and zinc levels inthe various sediment components can then be determined byapproprir.te chemical analysis. Since the technique physicallyseparates the sediment components it is possible to study notonly the total metal but also the biologically available heavymetal associated with each component. Work along these linesis in progress. In the present paper we describe the methodology of the density-gradient technique and give results fortwo selected sediment types.

Experimental

Collection of Samples. Sediment samples were collectedfrom Spencer Gulf, South Australia, several kilometers offshore from a large lead smelter. Divers working at depths ofapproximately 7 m forced the top 10 cm of sediment intoplastic tubes, which were capped at the top, withdrawn, andthen capped underneath. The samples were transferred toacid-washed polythene bags, cooled to 4°C, and filteredseveral days later. The damp salty sediments were dried in aclean stainless steel oven at 100°C. Oven drying may lead toirreversible changes in some sediment components and effectsof this nature are being investigated by comparing metaldistributions obtained after oven drying with those measuredafter freeze drying the fresh sediment.

Two of the sediment samples were selected for detailedstudy. Sample ES 26 was a grey, gritty near-shore sedimentcollected at 6.7 m depth in an area covered to about 90% bybroad-leafed Posidonia. Sample ES 35 was a brownish, oozysediment collected at 7.6 m depth in a shallow depressiondevoid of seaweed growth.

Separation into Size and Density Fractions. One-gramsamples of the dried sediment were suspended in 500 mL ofAR acetone and dispersed ultrasonically (l min, 20 kHz, 150W). Acetone, rather than water, was chosen as the dispersingmedium to avoid the possibility of the water removing weaklysorbed metals. The suspension was sized by repeated Stokes'law sedimentation in acetone into three size fractions: -1000+ 10 /lm, -10 + l/lm, and -I/lm. No flocculation occurredduring sizing of the freshly dispersed particles. Tests showedthat the concentrations of lead, zinc, and cadmium in samplesbefore and after washing with acetone were the same, indicating negligible removal of heavy metals by the acetone.

The preliminary separation of the sediment samples intosized fractions greatly facilitated the subsequent separationsinto density subfractions. By treating each size fraction separately, problems caused by the differing behavior of the largeand the very fine particles in the density gradient wereavoided.

Tetrabromoethane (TBE) was chosen as a base heavy liquid. Its sp gr of 2.96 is high enough to suspend most of the

0013-936XI79/0913-0295$Ol.00/0 © 1979 American Chemical Society Volume 13, Number 3, March 1979 295

DENSITY BANDS RETRIEVEO

Figure 1. Mineral bands observed after centrifuging sediment samplesin the heavy liquid density gradient

minerals commonly found in near-shore sediments. Laboratory grade TBE was further purified by redistillation at reduced pressure and the colorless distillate of sp gr 2.96 mixedwith acetone to give a series of liquids of sp gr 2.75, 2.66, 2.55,2.40, and 2.20. The liquids, in order of decreasing density, werecarefully layered into the double-walled centrifuge tube shownin Figure 1. About 0.5 g of sample was placed on the surfaceof the topmost density layer and the tube centrifuged at 1500rpm for 5 min (-1000 + 10 /Lm fraction) or 60 min (-10 + 1/Lm fraction). Distinct bands of particles of similar densityformed at the interfaces between the liquid layers (Figure 1).The system was maintained at a constant temperature duringprolonged centrifuging to prevent intermixing of the bands.Sample masses greater than 0.5 g were avoided, as some of thedenser particles were then entrained in the upper low-densitylayers.

The various density bands were removed in order by displacement with pure TBE. (An appropriate apparatus isavailable from T. W. Wingent Ltd., Cambridge, England.) The-1000 + 10-/Lm particles were washed free of TBE on anacid-rinsed and dried Buchner funnel, weighed, and thenanalyzed for heavy metal content.

Particles finer than 10 /Lm tended to flocculate in theTBE/acetone mixtures, but polyvinylpyrrolidone (PVP) wasfound to be an effective dispersant. A 1% solution of PVP inacetone was used as the diluent in preparing the topmostdensity layer. It was also found that bands formed from the-10 + 1 /Lm size fraction were removed more easily with aPasteur pipet. The particles were washed free of TBE by repeated centrifugation in acetone.

The finest particles (-l/Lm) could not be separated intodensity fractions with the conventional centrifuge used in thiswork.

Tests were made to establish whether TBE extracted heavymetals from sediment particles during the density fractionation procedure. The residue of TBE and acetone after afractionation experiment was analyzed by atomic absorptionspectrometry (AAS) using a carbon furnace and standardsprepared from metal salts of cyclohexylbutyric acids. Theconcentration of lead in the residue was <0.01 ppm and thatof cadmium was <0.002 ppm, showing that in this system TBEdoes not solubilize lead or cadmium. Preliminary tests showedthat the level of zinc in the TBE was also very low «0.1ppm).

Analysis for Heavy Metals. The density subfractionsranged in mass from 1 to 200 mg and required careful microanalysis. Suprapur nitric acid was added dropwise to the drysample in a platinum crucible until effervescence ceased (1mL per 200 mg); Suprapur perchloric acid (2 mL) was thenadded and the mixture heated to fumes. After cooling, 5 mL

296 Environmental Science &Technology

of Suprapur hydrofluoric acid was added and the mixturestood for several hours before heating to fumes. A fllrther 2mL of perchloric acid and 2 mL of hydrofluoric acid wereadded if necessary. Occasional black specks remained in somedigests. In others, a fine white crystalline precipitate formedon cooling. This was shown to be potassium perchlorate andappeared when potassium levels in the minerals were high,e.g., muscovite. Tests showed that there was no coprecipitationof lead, cadmium, or zinc with the potassium perchlorate. Thedigests were made up to 10 mL with double distilled water inacid-washed volumetric flasks; the pH of such solutions was<1.

Concentrations of lead and cadmium in the acid digestswere determined by AAS using a graphite furnace. The assembly comprised a Perkin-Elmer Model300SG atomic absorption spectrometer, an HGA-74 furnace, and a 2100 furnace controller. Deuterium source automatic backgroundcorrection was used throughout the analytical program. Withsome of the solutions, the concentrations of lead and cadmiumwere high enough to permit useful confirmatory data alsobeing obtained by conventional flame atomic absorption. Forthe zinc determinations, conventional flame AAS was used,as zinc concentrations in the digest stock solutions were highenough in all cases (0.1-10 /Lg/mL). This approach was preferred to the graphite furnace, in order to avoid the highdilution (300X) which would otherwise have been required.In all cases background correction was made to compensatefor nonatomic absorption produced by the high concentrationsof calcium present (up to 5000/Lg/mL).

The greatly increased sensitivity of the graphite furnaceallowed the original stock solutions to be diluted 10 times forthe determinations of lead and cadmium. Determinations ofcalcium, iron, aluminum, and potassium were also made onthe diluted solutions to ensure that adequate correction formatrix effect was being made. This approach was preferredto separation of lead and cadmium from the matrix, thussimplifying processing and minimizing the risks of contami-nation. '

For the analysis, a 20-/LL aliquot of diluted solution wasused, except in the case of several high lead concentrationswhere 10 /LL was used. Furnace processing conditions were:dry 110 cC, 40 s; ash 400°C, 20 s; and atomize,lead 2300 °c,cadmium 1700 DC, 6 s. Ramping was beneficial on all threecycles. To cover the wide concentration range'with absorbancevalues maintained between 0.05 and 0.5, the lower sensitivitylead line at 283.3 nm was used in addition to the 217.0-nm line.Increases in sensitivity, where required, were obtained byusing the gas-stop facility.

Calibration ranges were, for lead, 0.01-0.5/Lg/mL, and, forcadmium, 0.001-0.02/Lg/mL. Detection limits were lower thanthese limits but were only of interest for evaluating blankvalues.

Mineralogical Analysis. All mineralogical analyses werecarried out on duplicate samples to those prepared for heavymetal analysis. Microscopic observation and X-ray diffraction(XRD) techniques were used to identify the main mineralspresent in the unfractionated sediment and in the variousdensity subfractions. These methods also gave an approximateindication of the proportions of the major minerals.

Where enough sample was available, a semiquantitativemineralogical analysis was made. The sample was completelydissolved in a mixture of nitric, perchloric, and hydrofluoricacids (see the preceding section) and the concentrations of themajor elements Ca, Mg, Na, K, Fe, AI, Si, and Ti were determined by direct flame AAS. The elemental concentrationswere assigned to the various minerals known to be present, andthe proportion by weight of each mineral was calculated. Forthe minerals calcite, magnesian calcite, kaolinite, and goethite,an independent measure of their concentrations was obtained

Table I. Mineralogical Analysis· of UnfractionatedSediments

Table II. Mineral Components of the DensitySubfractions

a The term conglomerate is used here not in the geological sense.

a Near-shore sediment sample ES 26 (-1000 + 10 I'm). b Weight of subfraction too small to collect «0.5 mg).

Table III. Reproducibility of Heavy Liquid DensityGradient Technique

density conen 01 Zn, ppm distribution 01 Zn, %subfractlon oil run 1 run 2 run 1 run 2

<2.55 339 364 49 492.55-2.66 79 74 34 302.66-2.75 85 85 11 152.75-2.95 43 35 6 6

>2.95"

heavy minerals (0.2%wt); translucent brownand green particles oftourmaline, ilmenite;opaque blackparticles ofmagnetite; opaquegolden roundedparticles

sample ES 35(+10 I'm)

clay conglomerates 8

(8 % wt); solt goldenbrown conglomeratesof magnesian calcite.mica, kaolin. quartz,and goethite; a fewblack vitreousparticles

conglomerates (40%wt); solt brown andoff-whiteconglomerates ofmagnesian calcite,mica, some kaolin.quartz, tracesgoethite, feldspar

quartz + calcite shells(42% wt); mostlyquartz; some calciticshell fragments. a fewhexagonal rods

magnesian calcite shells(4% wt); as for ES 26but including someblack particles ofirregular shape

aragonite shells (6 %wt); as for ES 26

quartz + calcite shells(46% wt); quartz andcalcitic corallinestems, hexagonalrods, microshells

magnesian calcite shells(20 % wt); opaquewhite shell fragmentsand wholemicroshells ofmagnesian calcite;some coralline stemsand tubes

aragonite shells (19 %wt); thin shiny shellfragments ofaragonite; sometransparent platelets

heavy minerals «0.1 %wt); as for ES 35

2.75-2.95

2.66-2.75

2.55-2.66

>2.95

in an equivalent weight of unfractionated material. (Thiscomparison tests both the separation technique and the analytical method.) It may be seen from Table IV that the massbalances obtained for lead and cadmium were satisfactory butthat there was apparently some loss of zinc during fractionation. The reason for the poor mass balance for zinc, which wasalso observed in other samples, is being investigated.

Heavy Metal Content of Size Fractions. Results are given

wi %b dens«y sample ES 26sample sample subtraction (+10 I'm)

minerai ES 26 ES 3S<2.40 organics (9 % wt);

calcite + magnesium calcite 55 30 mostly organic debris;aragonite 20 5 a few solt whitequartz 10 30 conglomerates of

kaolinite 15 magnesian calcite

mica (muscovite) 10and quartz

goethite ~1 5feldspar 5 5

2.40-2.55 conglomerates (6 % wt);heavy minerals (ilmenite, tourmaline, <0.1 ~.2 solt white

magnetite, etc.) conglomerates oforganic debris ~5 <1 magnesian calcite,

total 96 100quartz, a littlefeldspar

8 Analysis by XRD, AAS, OTA. and density fractionation. b Values rounded105%.

by differential thermal analysis (DTA). By separating thesample into subfractions of equal density (see section onSeparation into Size and Density Fractions), a further checkon the mineralogical composition was possible. However, notall subfractions consisted of a single mineral species, so thismethod was only approximate.

Results and Discussion

Components of the Sediment Samples. Semiquantitativemineralogical analyses showed that the two sediment samplesES 26 and ES 35 had quite different mineral compositions(Table n. Sample ES 26 was composed mainly of shells andshell fragments with a significant proportion of organic debris.On the other hand, sample ES 35 contained much less shellgrit and organic debris but more quartz, clays, and iron oxides,reflecting the nature of the barren shallow trench from whichES 35 was collected.

Further information about the structure of the sedimentwas obtained by analyzing the density subfractions. The results (Table II) show, for example, that the mica, kaolin, andgoethite occurred almost entirely in the conglomerate particles. Most of the kaolin was present in the lightest densitysubfraction «2.40), whereas the mica was distributed in boththe "clay conglomerate" «2.40) and "conglomerate"(2.40-2.55) subfractions of sample ES 35.

Table II also shows that calcite and magnesian calcite werepresent in whole shells, shell fragments, and conglomerates,but that nearly all the aragonite occurred in shell fragments.Quartz was found both as free particles and in conglomerates.

It is clear that the heavy liquid density gradient techniquehas several advantages for the mineralogical analysis ofsediments: free organic debris floats to the top of the gradientand can be separated from inorganic components; aragoniticand calcitic shells are clearly separated; conglomerate particles, because of their porosity, report in a separate densityband.

Reproducibility and Accuracy of the Density GradientTechnique. The reproducibility of the heavy liquid densitygradient technique was tested by comparing the zinc datafrom duplicate fractionations of sample ES 26. Table III showsthe concentrations of zinc and the distribution of zinc betweendensity subfractions for each of two duplicate runs. It is evident from Table III that the reproducibility was satisfactory.

An assessment of the accuracy of the technique was madeby comparing the sum of the individual amounts of heavymetal present in the density subfractions with the heavy metal


ES 35

ZINC CONCENTRATION

ES 26

I I IOrCJOntC CongkJtntoroln Quartz IoloCjl",.slIln Atoglmlledebt's • cOlcite slwlls

calcite shellsstwtls

~~ 400

za

~ 3000:...z~200zau

~ 100N

500..---------------,

Figure 3. Concentrations of zinc in the density subfractions separatedfrom sediment ES 26 (-1000 + 10 I'm). See Table II for a descriptionof the subfractions. The weight of '"heavy minerals'" in ES 26 was toosmall to collect

."" I°__ 0 ____I100

0l!---'-----'-----'----'

Ff__o~------,O O~Z1_N_C_

CAOtollUM

o-o~o

Size fraction

Figure 2. Variation of heavy metal concentrations with particle size forthree sized fractions of sediment ES 35

• Near-shore sediment sample ES 26 (-1000 + 10 I'm). • Weight of subtraction too small to collect «0.5 mg).

Table IV. Mass Balances for the Density FractionationTechnique

Cd

Pb Zn

~

100"§~

g 80:0

.£c 60.Q

i 40

. 20>-;;..0:

Otlpnic CQn9I_rolP5dltbris;

RELATIVE CONCENTRATIONS OF HEAVY METALSES 26

Figure 4. Relative concentrations of lead, cadmium, and zinc in thedensity subtractions of sediment ES 26 (-1000 + 10 I'm). Absoluteconcentrations in organics subtraction normalized to 100 units

22.017.13

18.129.23

3.58

60.072.4

2.562.36

0.9850.325

0.4700.5850.194

mass of heavy metal present, p.g

Pb Cd Zn

45.544.6

19.745.74

11.046.642.33

densitysubfracllon •

<2.42.4-2.55

2.55-2.662.66-2.752.75-2.95

>2.95 b

totalunfractionated sample

in Figure 2 for the concentrations of heavy metals in each ofthe three size fractions of sample ES 35. The concentrationsof zinc and cadmium decreased with particle size, while theconcentration of lead increased slightly. Since the -i-I'mparticles accounted for only 5% of the total weight of sedimentES 35, their contribution to the total heavy metal content wasrelatively small and they were not studied in detail. However,in freshwater sediments where the proportion of discrete ultrafine particles is likely to be larger, density fractionation ofthe -i-I'm fraction may be necessary.

It had been expected that the finer particles, because oftheir larger surface area, would contain more metal. Thereason that this was not observed may have been that manyof the so-called "particles" in the -1000 + 10 I'm fraction werein fact conglomerates of much finer particles (see Table 11).Some of these conglomerates were soft and broke apart easily;others were quite hard. The conglomerates consisted of amixture of fine magnesian calcite, mica, kaolin, quartz, andgoethite. Similar conglomerate particles were also observedin the original wet sediment, and it appears that they are a realcomponent of the sediment and not an artifact of ovendrying.

Heavy Metal Contents of Density Fractions. The concentrations of lead, cadmium, and zinc were found to varybetween the density bands in each sample and between similarbands in different samples. The results below show the usefulness of the density separation technique rather than theenvironmental significance of the metal concentrations. Figure3, for example, shows the variations that can occur betweendensity bands. Zinc concentrations were highest in the organic

debris, and significantly less zinc was associated with aragonitic than with calcitic shells.

Lead and cadmium were also preferentially concentratedin the organics subfraction (Figure 4), but the ratio Pb:Cd:Znwas similar in each subfraction regardless of mineralogy.

The results in Figures 3 and 4 apply to the size fraction-1000 + 10 I'm, but similar concentration patterns were foundin the -10 + i-I'm fraction. The same patterns probablypersisted in the finest particles (-1 I'm), but this could not beproven because density subfractions could not be separatedwith a conventional centrifuge. However, the -i-I'm particlescontain only a small proportion of the total heavy metal insamples ES 26 and ES 35, and therefore the concentrationpatterns in the -1000 + 1O-l'm particles reflect those of thewhole unsized sediment.

Distribution of Heavy Metals. It could be argued thatthose sediment components with the highest metal contentare the most important to the local ecosystem. Thus, in thecase of sample ES 35 (Figure 5), one might assume that theheavy minerals were the key source of heavy metals in a foodchain that began in the sediment. However, this argumentignores possible variations in the ease with which heavy metalsmay be extracted from different sediment components. Also,no account is taken of the fact that the total amount of metalcontained in, say, the heavy minerals may be less than thetotal amount in another more abundant component with alower concentration of heavy metal.

In sediment ES 35, for example, the heavy minerals subfraction contained 792 ppm of lead but contributed only 1.5%to the total lead content of the sediment (Figure 5). The environmental significance of the heavy mineral lead would be


LEAD CONCENTRATIONES 35

A.ppm) but contained 36% of the total zinc and was the majorreservoir of zinc in the sediment.

LEAD DISTRIBUTION

ES 3S

BOO

i~ 600

c.~;;~ 400

~8

"0

~ 200

IClay Con9lom.

cO"910m.

•Quarll

•s.... lls

I •Aragoniteshells

B.

Conclusion

The heavy liquid density gradient technique has beenshown to be suitable for the separation of the mineral components of near-shore sediments as a basis for the assessmentof the concentration and distribution of heavy metals. Adequate sensitivity for the determination of lead, cadmium, andzinc in the density subfractions was obtained using eitherdirect flame or graphite furnace atomic absorption spectrometry.

The technique avoids the problem of nonselective dissolution encountered with chemical methods of determiningmetal distributions, and, as the present work has shown,provided that the sediments contain only a small proportionof discrete ultrafine particles, accurate and reproducible datacan be obtained. The concentration and distribution patternsrevealed should be useful in evaluating the environmentalsignificance of contaminated sediments.

Figure 5. (A) Lead concentrations in the density subtractions of sedimentES 35 (-1000 + 10 11m). (8) Distribution ot lead between the densitysubtractions of sediment ES 35 (-1000 + 10 11m). See Tabie 1\ for adescription of the subfractions

reduced still further if it could be shown that it was presentas insoluble particulate matter.

A different concentration-distribution relationship wasobserved for zinc in sample ES 26, where the organics subfraction had not only the highest concentration of zinc (490

40 Literature Cited

(1) Piper, C. S., "Soil and Plant Analysis", University of AdelaideAdelaide, S. Australia, 1950. '

(2) Agemian, H., Chau, A. S. Y., Analyst (lAmdon), 101, 761-7(1976).

(3) Schmidt, R L., Garland, T. R, Wildung, R Eo, "Copper in SequimBay Sediments", Battelle Pacific Northwest Laboratory AnnualReport, Part 2, p 136, 1975.

(4) Malo, B. A., Environ. Sci. Techno/., 11,277-82 (1977).(5) Subramanian, V., Experientia, 31 (1),12-3 (1975).(6) Muller, L. D., Burton, C. J., "The Heavy Liquid Density Gradient

and Its Applications in Ore Dressing Mineralogy", Proceedings ofthe EIghth Commonwealth Mining and Metallurgical Congress,Melbourne, AustraIJa, Vol. 6, pp 1151-63, 1965.

(7) Francis, C. W., Bonner, W. P., Tamura, T., Soil Sci. Soc. Am.Proc., 36 (2), 366-76 (1972).

(8) Francis, C. W., Brinkley, F. S., Nature (London), 260,511-13(1976).

Received for review June 2, /978. Accepted September I, /978.

Acknowledgment

The authors thank Dr. K. G. Tiller for collecting the sediment samples and Dr. J. D. G. Hamilton for assisting with themineralogical analyses.

A-rogonitl' Hl'avy5....US mi",.rols

BO

0'60

co~

.c.'0"0o~ 20

CoagUlation and Direct Filtration of Humic Substances with Polyethylenimine

Harold T. Glaser1 and James K. Edzwald'

Department of Civil and Environmental Engineering, Clarkson College of Technoiogy, Potsdam, N.Y. 13676

The National Organics Reconnaissance Survey by EPAindicated that the presence of trihalomethanes in drinkingwater is widespread in the U.S. (J). The presence of theseorganics constitutes a public health problem since the occurrence of chloroform in potable water has been statisticallyassociated as a cancer risk (2, 3); consequently, EPA hasproposed a Primary Drinking Water Standard of 100 I1g/L fortotal trihalomethanes. Several investigators have shown thatthe chlorination of waters containing humic substances resultsin trihalomethane formation (4-7); i.e., humic substances are

1 Present address, James M. Montgomery, Consulting Engineers,Inc., 1990 N. California Blvd., Walnut Creek, Calif. 94596.

precursors in this reaction. Humic materials are also responsible for the natural color imparted to waters and are usuallyremoved by coagulation with alum followed by sedimentationand filtration. Humic substances are amorphous, acidic,predominantly aromatic, hydrophilic, chemically complexpolyelectrolytes or macromolecules. The substances exist ina range of molecular weights, from a few hundred to tens ofthousands (8, 9) with a size estimated in the range of 3.5-10nm (10). Humic substances are negatively cbarged macromolecules for the pH conditions of most natural waters andcan be classified as colloidal matter due to their colloidal dimensions. pH will affect both the charge density and configuration of the humic macromolecules in solution. As the pH

0013-936XI79/0913-0299$01.00/0 © 1979 American Chemical Society Volume 13. Number 3. March 1979 299

• A series of polyethylenimine polymers (cationic) withmolecular weights from 600 to 50000-100000 was used incoagulation and direct filtration studies of humic acid at pH5.5-6. Destabilization of humic acid is achieved where theoptimum polymer dosage is independent of molecular weight;however, solid/liquid separation of floc in the jar tests is poordue to poor particle contact opportunities. The direct filtration of humic acid is an effective treatment process with

continuous polymer feed. The filter aid dosage can be selectedfrom jar tests as coagulation and filtration are analogous.Polymer dosages which produce under- and overdosing in thejar test also produce identical effects in direct filtration.Greater head loss was observed for direct filtration withoutflocculation. A brief flocculation period results in particleaggregation, an increase in the mean size of the particles beingapplied to the filter bed, and lower head loss development.

No Flocculation Provided

Flocculation Periods of 7.3,13, and 30minutes

Figure 1. Schematics of filtration apparatus used for experiments with0-,7.3-, 13-. and 3D-min flocculation time


Destabilization of Humic Acid with PEl. Figure 2 showsresults of jar tests performed on synthetic water with PEI-6and -1000. The optimum dose for PEI-6 is 0.8-1.0 mglL andfor PEI-lOOO it is approximately 3 mg/L. Over- and underdosing are observed in both cases. At the optimum dose, apparent color removal is about 50% for PEI-6 and nonexistentfor PEI-lOOO. Turbidity removal is also poor. Visual inspectionof the jars indicated formation of small unsettleable floc. Theremoval of true color indicates that destabilization of thehumic acid has occurred, but sedimentation is not effective.This can be explained as follows. Initially, peri kinetic flocculation is rapid due to a large number of submicron humicparticles; however, as the particles are aggregated to the micron size range, the particle number decreases and the formation of large aggregates by orthokinetic flocculation islimited due to low rates of particle contacts. Therefore, thejar test is a satisfactory model for determining the optimumpolymer dosage for destabilization but for these colloidalsystems good solid/liquid separation is not achieved.

A stoichiometry between the initial humic acid concentration and the optimum dose is shown by the results in Figure3 for two PEl polymers of widely different molecular weights.These stoichiometric results are summarized in Table I. Inaddition, other jar test experiments involving 5 mglL humicacid showed the optimum polymer dosages to be 0.8-1.0 mglL

lowing molecular weight fractions (number average) wereused: 600 (PEI-6), 1200 (PEI-12), 1800 (PEI-18), 4000060000 (PEI-600), 50000-100000 (PEI-lOOO), and 6000080000 (PEI-1090). Humic acid concentrations were determined by measuring absorbance using a Bausch and LombSpectronic 710 spectrophotometer (420 nm, 5-cm cells) andcomparing with a standard curve. Apparent color measurements were made at pH 6 with no pretreatment; true colormeasurements were made by filtering samples through a glassfiber filter and adjusting the pH to 11 prior to reading absorbance. Residual turbidity was measured with a Hach Model2l00A turbidimeter.

A bench scale laboratory pilot filter was designed andconstructed from 2.54 cm (l in.) i.d. plexiglass columns. Thiswas a conventional downflow rapid sand filter operating at 5m/h (2 gal min-I ft- 2). Sieved and washed Ottawa sand wasused as the filter media with a geometric mean size of 0.6 mm,a bed porosity of 0.4, and a bed depth of 14 cm (5.5 in.). Colorremoval by direct filtration was investigated with and withoutflocculation prior to filtration as shown by the schematic diagrams in Figure 1. Flocculation time was varied using different size reaction vessels which were completely mixed toprevent particulate removal during the flocculation step. Priorto each run, the filter bed was precoated with concentratedpolymer solution (l giL) and rinsed with distilled water toremove excess polymer. During the filter run, polymer was fedcontinuously at the desired dose. The effluent was analyzedfor apparent color, turbidity, and pH. Head loss through thebed was monitored by a mercury manometer from taps on thefilter column. A detailed explanation of these procedures isavailable elsewhere (I J).

ManometerTapSand Bed

MancmeterTap

Sand Bed

Polymer

FlocculationReactor

SyntheticWater

is increased, increasing stability will result due to dissociationof carboxyl and phenolic functional groups. An extendedconfiguration would be expected with increasing pH due torepulsion between charged functional groups.

A reexamination of water treatment technology is neededto improve existing processes and to develop new processesfor the removal of humic substances (trihalomethane precursors) from water supplies. The research reported here isa laboratory scale feasibility study of the direct filtrationprocess for removing humic substances from water includingan examination of the physical and chemical parameterswhich affect it. Specific objectives are: to examine the destabilization of humic acid by polyethylenimine; to determineif the filter aid dosage can be selected by a laboratory jar test;to examine the effect of flocculation on filter efficiency andhead loss; and to examine the effect of polymer molecularweight on filter efficiency and head loss.

Methods

The coagulation process was modeled by the standardlaboratory jar test procedure. A synthetic colored water wasprepared with 5 mglL humic acid (Aldrich Chemical Co.) and2 X 10-3 M NaHCO;l for alkalinity and ionic strength. The pHwas adjusted to 5.5-6 with 1 N HCI which was constant for allexperiments. The PEl (polyethylenimine) series of polymers(Dow Chemical Co.) was used which permitted examinationof the effect of molecular weight. Polyethylenimine is a highlybranched polyamine produced by the acid-catalyzed polymerization of the monomer, ethylenimine (C2NH,,). The fol-


25

PEI-IOODIndiolHumic AcidConC/lnlra/ion• IOmg/1• 5mg/1.2.5mg/1True Color

....'" 8E

""<:;<t

°0~-~2---4~------;----=----"O'

Polymer Do se

Figure 3. Stoichiometry of coagulation of humic acid with PEI-6 andPEI-1000

l0l'==---------~-_____,

g" 2"in

'"a::

~ 8

.f".<:;<tu

~ 4:r:

ro"",=_~-_--~--_---,

::J1.6 I-

Z

12'i5:e::>

0.8 f-

e::>

"0.' .;;;

'"a::

05

50

'.0 =>f-t;

3.0>-

'i5:c

2.0::>f-

g10 ".;;;

'"a::

025

PE/-6o True Color• Apporenl Color

I 2 3

Polymer Dose lmg/Il

,---~-----.t------"""-="'2.0

'"c:~ 0.6

'0 eu E<t '"a:: 0.'u c.~ e

1: g0.2

..::0

0

°0'--~5--~10--~'5---2~0---'

Polymer Dos e (mg/I)

Figure 2. Jar test results for PEI-6 and PEI-l000. Raw water: 5 mg/Lhumic acid. pH 5.5-6

Initial Chemical Interaction

Table I. Stoichiometry of Coagulation of Humic Acidwith PEl

PEI-6 PEI-1000

optimum dose, mg/L

Humic Acid Cationic Polymer Destabilized Particle

1.53.05.5

0.40.8-1.0

1.6

humic acid,mg/L

2.55

10

Figure 4. Schematic representation of humic acid/PEl destabilizationand aggregation

of PEl, but charge neutralization is significant where thenegatively charged carboxyl groups existing on the humic acidare neutralized by the PEl cationic amine groups. This issupported by the stoichiometry observed in Figure 3 and bythe results indicating no effect of PEl molecular weight on theoptimum dosage. A schematic of the destabilization step isillustrated at the top of Figure 4, which shows that as thepositively cbarged PEl is added, a rapid chemical interactionoccurs due to strong electrostatic forces between the oppositely cbarged macromolecules. Other chemical forces suchas hydrogen bonding may also be involved. The mechanismof aggregation is shown at the bottom of Figure 4, where alternating layers of polyelectrolyte and humic matter are interwoven and attached to each other. This cross-linking ishighly cbarged initiated and chemically preferred. Eachgrowing aggregate would attract more polymer or humic

for PEI-12 and PEI-18 and 3 mglL for PEI-600and PEI-l090.Accounting for dilution (the high molecular weight fractions-PEI-SOO, -1000, and -1090-are diluted by one-thirdby the manufacturer for ease of handling (12)), the optimumdosages are approximately the same regardless of molecularweight. Furthermore, since the PEl polymers are a homologous series, the number of positively charged amine groupsper unit weight would be approximately the same (neglectingreduced basicity of specific amine groups due to adjacentcharged groups), indicating charge neutralization is significantin the coagulation of humic acid by polyethylenimine.

The mechanisms of destabilization and aggregation ofhumic acid by PEl cannot be explained by classical coagulation models. Cationic polyelectrolytes are usually depicted asaccomplishing colloidal destabilization by charge neutralization and/or interparticle bridging. These destabilizationmechanisms have been developed for colloids with well-defined solid surfaces such as latex particles, silica sols, clays,algae, and bacteria. Some modification of existing models isneeded and a proposed model for destabilization and aggregation of humic substances by PEl (cationic polymers) follows.

The humic acid is negatively charged at pH 5.5-S due todissociation of the carboxyl groups on the humic acid molecule. Titration of the humic acid with NaOH in 0.1 N NaCIindicated a pK of 4.51 for the carboxyl groups. Classical interparticle bridging is not likely due to the size and structure

Destabilized Particles Cross UnkedFlocPorticle


PEI-IOOOO.5mg/1

3mg/1... IOmg/1

30 min. floc. limtl

PEI-IOOOTrul!I Color

5 to 15 20 25

Polymer Dose (mg/l)

g'O.8c

"cE 0.6·u'"" a::

u g 0.4

~ -uI c

u: 0.2

00

1.0

0'c OBcc_E C 06'" ~0:::::Cw 0.4c';.~

c0.2u:

o L...:.....~.................-+-+-_................~-,-Jo 60 120 180 240 300

Filtrotion Time (min)

Figure 6. Comparison of jar test results with filter performance forPEI-1000. Raw water: 5 mg/L humic acid

u.~

I

300

PEt-6.Olmg/I.'.Omg/IA'Omg/130min.floc./ime

1.0

0.8P£l-6TruB Color

:?·c

0.6" ·cu E" '"a::u c 0.4.~ 0

I uc

0.2Il:

00 I 2 3

POI ymer Dose (mg-1)

:?·c

"U'o 'u E ;

" '" "u~::'E.2 W 0.4, - c

:I: g.-LL 0.2

oL!:=O::::_~~_~~~_~~--J

o 60 120 180 240

Filtration Time Imin)Figure 5. Comparison of jar test results with fi~er performance for PEI-5.Raw water: 5 mg/L humic acid

matter depending on the specific site or overall charge.The ability of PEl to chemically interact with organic

molecules is well documented (13). Nedelcheva and Vladimirov (14) postulated that hydrogen bonds were formed between the polymer amine groups and phenol and carboxylgroups on cellulose molecules. The hypothesis was the cellulose adsorbed the PEl as well as other cellulose fibers whichhad already adsorbed PEL The structure of cellulose has manysimilarities with those postulated for humic acid. Other investigators have described specific chemical interaction between PEl and anionic linear polymers (15) and lignin (16).Kisla and McKelvey (17) have reported on color removal fromsoftwood kraft pulp bleach plant effluent using cationicpolyamines and describe a mechanism of destabilization andaggregation similar to ours.

Analogy between Coagulation and Filtration. Figures5 and 6 show jar test results and filter runs where the optimumdose from the jar test was used for filtration. Filter runs werealso conducted using dosages which were over- and underdosed in the jar tests. Removal is good at the optimum dose(1.0 mg/L) for PEI-6 (Figure 5). The underdosed filter (0.1mglL) exhibits good removal initially, but deteriorates rapidly.This is due to rapid exhaustion of the precoat capacity of thebed. The overdosed filter (10 mglL) removes almost no humicacid. In this filter run, the humic acid is restabilized and willnot attach to the collector. Similar behavior is observed forthe PEI-1000 systems (Figure 6). The removal efficiency atthe optimum dose of PEI-1000 (3 mg/L) is 100%. Again, theremoval efficiency for the underdosed filter (0.5 mglL) is goodinitially and deteriorates rapidly while the overdosed filter(10 mg/L) removes none of the humic acid. These runs weremade with a 30-min flocculation period; similar results werefound for filter runs using other flocculation periods andwithout flocculation prior to filtration.

Filtration and coagulation are analogous as the optimumPEl dose in filtration is the same as the jar test prediction.This phenomenon was portrayed by Yao et al. (18) and Habibian and O'Melia (19), and supported by others (20). Thejar test predicts the optimum filter dose because it can predict

the optimum chemical dosage required for destabilization ofcolloidal particles regardless of whether the colloids are in abeaker or in a filter (21). Filtration is a two-step process involving particle transport and attachment to collectors (22).Billings' observations (23) and the work of Tien, Wang, andBarot (24) and Payatakes and Tien (25) in aerosol filtrationhave shown that particle deposition on collectors may belargely on previously retained particles in a dendrite-likefashion. This type of occurrence would account for the similarities in the particle surface chemistry of destabilization incoagulation and attachment in filtration.

Coagulation is also a two-step process of particle destabilization and transport. In coagulation, the rate-limiting stepis aggregation of the destabilized particles to form settleablefloc. For dilute synthetic colored water systems, particlecontact opportunities in the jar test are very poor. This is reflected in the poor removal of apparent color. Filtration,however, is to a first approximation, independent of particleconcentration. Transport efficiency and consequently removalare very good when effective destabilization has been provided. Filter ripening was observed in several runs at the optimum dose. This is the improvement in removal efficiencyabove that of the clean bed from added particle removalcaused by the retained particles.

Figure 7 shows a typical run with effluent turbidity andhead loss data where, after the ripening period, effluent turbidities are generally less than 0.4 NTU (nephelometric turbidity unit). Head loss data for this and all subsequent runsare expressed in inches of water. Two filter runs were madeto determine the operating range of polymer dosage for goodremoval. Figure 8 shows runs where the polymer dose wasvaried without a flocculation period so that the effect of dosingon the bed was instantaneous. PEI-6 and PEI-1000 showedranges of 0.8-1.5 and 2-3.5 mg/L, respectively, for good removal. This operating range is within the capability of awell-operated water treatment plant.

Effect of Flocculation. A series of eight filter runs wasmade to examine the effect of flocculation on filter efficiency


1.0~-------------~2.0 I.O~--------------,

PEl-6~/m9/1

• Omin floc lime1& 7.3mln f1oc.lifT't!• f 3min. floc. fime.30mi" II oc Nme

40

OB

'""~.~ ~O.6~E~

"0::-u c WOA

"E 0 c~''::' .Iu

oIt

o..J 20

"o"I 10L'::::1:i~~r=*"V"

:::JfZ

".0

1.0 ~

f-

-'" 30

'"o..J 20

"o'"I 10

40

'"c 0,8

"'0 ~

~ ~ ~O.6~n:~

,,-u 0 WO.4

'E :;:.=" u

I 0 0.2

.::

oL~~~_~~~~_~~---Jo 60 120 180 240 300

Filtrotion Time (min.)

Figure 7. Filter performance for PEI-6 at O-min flocculation time. Rawwater: 5 mg/L humic acid

OL~~-~~~-~~~-~--'

o 60 120 180 240 300Filtration Time (min.)

Figure 9. Effect of flocculation time on filter performance for PEI-6 atoptimum dose. Raw water: 5 mg/L humic acid

10~--------------,

PEJ-IOOO=3mq/1• Omin floc lime.. 7 3m/nllac. time• 13min.floc lime+30min floc. lime

'" 30

0.8

I

o..J

0'

"P£l-6

PEI-IOOO

0.8

go'c

-0 '0 C'u E Q)

<t " "a: ;;: 0.4

.~ .~w"- "I g'- 0.2

It

300oL~~-----';~~"'4~~~~-----Jo 60 120 180 240 300

Filtrotion Time (min)

Figure 8. Operating range for PEI-6 and PEI-1000 for humic acid removal. Raw water: 5 mg/L humic acid

60 120 180 240Filtration Time (min,)

Figure 10. Effect of flocculation time on filter performance for PEI-100Dat optimum dose. Raw water: 5 mg/L humic acid

and head loss. Figure 9 shows results for PEI-6 at the optimumdose. With increasing flocculation time, some deteriorationin filter efficiency is noted which will be discussed later. Theeffect of flocculation on head loss development is of interest.A significant decrease in head loss is accomplished by providing some flocculation. Figure 10 shows that filter efticiencyis not a function of flocculation time for PEI- J000 at the optimum dose, indicating good destabilization and sticking ofparticles. Again, a much lower head loss development is observed when flocculation prior to filtration is provided. Dueto the mixing conditions employed in the flocculation vessels,increasing the flocculation period from 7.3 to 30 min did not

result in any additional decrease in head loss. As flocculationbegins, the predominant method of particle contact is perikinetic flocculation, but as the particles are aggregated intothe micron size range, additional particle growth by orthokinetic flocculation was restricted by shear forces at these longerflocculation periods.

What we wish to stress is that providing some flocculationperiod prior to filtration changes the size of the particles beingapplied to the filter bed which, in turn, affects head loss development. With flocculation, particles are aggregated andincrease in size. The bulk of attachment in a bed occurs onretained particles; resistance to flow or head loss depends onthe exposed surface area of the deposit. Flocculation of sub-


Om;n. floc./imeo P£I-6:Q8mg/1I:. PE/·/2=08mg//o PEt-/8=0.8mg/1• PEN090=3mg/1• PEI-600<Jmg/l• PEI"100~3mg/1

0.8

g'~ 0.6'c

'0'0

~=u<t

~ W04u.~ .~ .=

uI c 02

c::

Acknowledgment

The authors acknowledge the laboratory assistance provided during the study by J. Lancto and G. Gilot.

4a

'"'"c..J 2a..,c

"I

Conclusions

• The destabilization of humic acid by PEl at pH 5.5-6 ishighly charge dependent and is based on neutralization of theanionic functional groups by the cationic PEi amine groups.Aggregation may occur as humic and PEl molecules are randomly cross-linked by electrostatic and specific chemicalforces.

• A stoichiometry exists between the raw water humic acidconcentration and the optimum destabilization dosage ofPEL

• The direct filtration of humic acid with PEl is an effectivetreatment method.

• Filtration and coagulation are analogous as the optimumPEl dose in filtration is the same as the optimum destabilization dosage in the jar tests. Over- and underdosing phenomena are observed in filtration. Filtration is more efficientthan coagulation due to increased particle contact opportunity.

• The optimum PEl dosage is independent of the molecularweight of the polymer. For the pilot filters and conditions usedin this study, the removal efficiency of the filters operated atthe optimum dosage increased with increasing molecularweight of the polymer when a flocculation period was provided. Without flocculation, no effect of polymer molecularweight on filter efficiency was observed.

• Head loss development is substantially more rapid forsmaller humic acid floc. Provision of a flocculation periodred uces the head loss.

also observed for Grasse River water systems (27).A comparison of Figures 9 and 10 reveals that with in

creasing flocculation time, filter efficiency deteriorates forPEI-6 but not for PEI-lOoo. With increasing flocculation timefor PEI-6, the larger particles are incapable of remaining attached and are forced to penetrate deeper into the bed andinto the effluent. The PEI-1oo0 floc is stronger and retainedin the top portion of the bed.

a'--+---+-,-~-+-~~-+-~-~-+---'o 60 120 180 240 300

Filtratian Time (min.)

Figure 12. Effect of PEl molecular weight on filter performance at optimum PEl dosages. Raw water: 5 mg/L humic acid

'2a

Gross~ Ri'l~r Wale,

c.

i? a.'r-~~-~~-------,

:~ c 0.2 A. • F'E!/~~~h~~~ ~ r ~·.7-.J...hU..""'fIorC-'ine-J

o c::: 0.1o .2l.JJ pH"7.4<.> ~.~ 2.~alc---+--+-~>--+---+-'--+--+---l

'"-5~ 18

{;:e~ 1.0

~

~ 0.6 1--+---+--=:::=~~'::~::::~w O.2~

6a

30 60 90Filtration Time (min)

Figure 11. Effect of flocculation time on filter performance using Q-asseRiver water with PEI-1000.(A) Caior remaining in 1m", effluent; (8) effluent turbidity; (C) filter head loss data.Raw water: carof,70 Pt-Co units; turbidity, 5.9 NTU

micron particles prior to filtration reduces the surface areaof the retained or deposited particles by forming larger particles, resulting in lower head loss development.

This inverse relationship between particle size and head losswas observed by Habibian and O'Melia (19) for latex particles.O'Melia and Ali (26) have recently developed a quantitativemodel which illustrates the phenomenon. This observationhas significant ramifications in actual water treatment practice. Figure 11 shows filter efficiency for color and turbidityas well as head loss data for the direct filtration of Grasse Riverwater using PEl-WOO. The Grasse River is a highly colorednorthern New York ~ater; the water used in these experiments was collected at the intake to the Canton, N.Y. WaterFiltration Plant. From jar tests the optimum polymer dose wasfound to be 9 mg/L and was used in the filter experiments atpH 7.4. Initial color and turbidity of the raw water were approximately 70 color units and 5.9 NTU, respectively. Notethe substantial decrease in head loss with only a 7.3-minflocculation period. The head loss values obtained were muchhigher than any filter runs involving the synthetic color systems containing 5 mglL humic acid. This is undoubtedly dueto the presence of large quantities of submicron particles.Design of direct filtration processes for the removal of submicron particles should consider the provision of flocculationprior to filtration.

Effect of Polymer Molecular Weight. Six filter runs wereperformed without flocculation using the jar test optimumdosages of the PEl series for 5 mglL humic acid. Figure 12shows the results of these experiments. With no flocculationperiod, little effect was noticed on filter efficiency with changein molecular weight of the polymer. Greater head loss development is noted, however, for PEI-600 and PEl-WOO.

For a given amount of humic acid, destabilization is dependent on a given equivalent of positive charge provided bythe PEL For low molecular weight polymers, this chargeneutralization is provided by a larger number of PEl moleculesand the aggregates are not as strong as the tightly bound highmolecular weight PEl/humic acid floc. Visual inspection ofthe bed indicated that, for PEI-600 and PEl-WOO, removalis in the upper portions of the bed. The low molecular weightPEl/humic acid floc is not as resistant to shear since attachment is not as strong; therefore, it will penetrate the beddeeper and distribute head loss more evenly. This effect was


Literature Cited

(I) Symons, J. M., et aI., J. Am. Water Works Assoc., 67,634-47(1975).

(2) Tardiff, R. G., ibid., 69,658-61 (1977).(3) U.S. Environmental Protection Agency, Fed. Regist., Part III

(July 11, 1977).(4) Rook, J. J., Water Treat. Exam., 23,234-43 (1974).(5) Rook,J. J.,J. Am. Water Works Assoc., 68,168-72 (1976).(6) Stevens, A. A., et aI., ibid, 68,615-20 (1976).(7) Babcock, D. B., Singer, P. C., "Chlorination and Coagulation of

Humic and Fulvic Acids", presented at 97th Annual AmericanWater Works Association Conference, Anaheim, Calif., 1977.

(8) Schnitzer, M., Environ. Biogeochem., Proc. Int. Symp., 2nd, 1975,I (1976).

(9) Schnitzer, M., Kahn, S. U., "Humic Substances in the Environment", Marcel Dekker, New York, N.Y., 1972.

(10) Black, A. P., Christman, R. F., J. Am. Water Works Assoc., 55,753-70 (1963).

(11) Glaser, H. T., M.S. Thesis, Clarkson College of Technology,Potsdam, N.Y., 1978.

(12) "PEl Polymers ... Infinite Modifications, Practical Versatility",Dow Chemical Co., Designed Products Department, Midland,Mich., 1974.

(13) Kindler, W. A., Swanson, J. W., J. Polym. Sci., 9, 853-65(1971).

(14) Nedelcheva, M. P., Vladimirov, G., J. Appl. Polym. Sci., 20,2131-41 (1976).

(15) Parker, C. A., Joyce, T. A., ibid., 18,155-65 (1974).(16) Lautsch, W., et aI., J. Polym. Sci., 8, 191-213 (1970).(17) Kisla, T. C., McKelvey, R. D., Environ. Sci. Techno/., 12,207-11

(1978).(18) Yao, K., Habibian, M. T., O'Melia, C. R., Environ. Sci. Technol.,

5, 1105-12 (1971).(19) Habibian, M. T., O'Melia, C. R., J. Environ. Eng. Div., Am. Svc.

Civ. Eng., 101,567-83 (1975).(20) Ghosh, M. M., ,Jordan, T. A., Porter, R. L., ibid., 101,71-86

(1975).(21) Edzwald, J. K., Glaser, H. T., paper presented at the 175th Na

tional Meeting of the American Chemical Society, Anaheim, Calif.,Abstr. ENVR-081, 1978.

(22) O'Melia, C. R., Stumm, W., J. Am. Water Works Assoc., 59,1393-412 (1967).

(23) Billings, C. E., Ph.D. Dissertation, California Institute ofTechnology, Pasadena, Calif., 1966.

(24) Tien, C., Wang, C., Barot, D. T., Science, 196,983-5 (1977).(25) Payatakes, A. C., Tien, C., J. Aerosol Sci., 7,85-100 (1976).(26) O'Melia, C. R., Ali, W., "The Role of Retained Particles in Deep

Bed Filtration", paper presented at the Ninth InternationalSymposium, International Association of Water Pollution Research, Stockholm, Sweden, June 12-16, 1978.

(27) Glaser, H. T., Edzwald, J. K., "Removal of Naturally OccurringColor from Water Supplies by Coagulation-Direct Filtration",paper presented at the 98th Annual American Water Works Association Conference, Atlantic City, N.,1., 1978.

Received for review April 27, 1978. Accepted September 18, 1978.This paper was presented in part at the 175th Notional Meeting ofthe American Chemical Society, Division of Environmental Chemistry, Anaheim, Calif., March 1978. The financial support providedby Clarkson Collelie of Technology is gratefully acknowledlied.

Competitive Adsorption of 2,4-Dichlorophenol and 2,4,6-Trichlorophenol in theNanomolar to Micromolar Concentration Range

Carol J. Murin1 and Vernon L. Snoeyink*

Department of Civil Engineering, University of Illinois at Urbana-Champaign, Urbana, III. 61801

• This study shows how effectively trace amounts of chlorophenols are adsorbed by activated carbon under the competitive conditions encountered in natural waters. Chlorophenols are odor-producing contaminants which form in watersupplies via the reaction between chlorine and phenol duringdisinfection, and activated carbon is one of the best-availablemethods for removing chlorophenols from water. Strongcompetition was observed between anionic and neutral speciesof dichlorophenol and trichlorophenol even at the Il'gf.L level.Of the competitive adsorption models studied, the Langmuirmodel best fit the observed data. Evaluation of the competitive adsorption between chlorophenols and humic substances,which are present in nearly all municipal water supplies, indicated that the presence of these materials decreased thecapacity of carbon for chlorophenols. The extent of competition was dependent on the source of the humic substancesand pH was found to have a significant effect on the adsorption of both chlorophenol and the humic substances.

The objective of this study was to examine activated carbonadsorption of a mixture of chlorophenols in the nanomolar tomicromolar concentration range. Chlorophenols at this concentration form during municipal water purification via thephenol-chlorine reaction. Phenol is present in water suppliesowing to industrial discharges and to decay processes andchlorine is added as a disinfectant. Chlorophenol removal isnecessary because their presence is the cause of many com-

1 Present address, Sodemann and Associates, Inc., Champaign, 111.6l820.

plaints of odor in finished water. Previous works by Burtschellet al. (I) and Lee (2) give many details about the chlorinephenol reaction and chlorophenolic odors. 2-Chlorophenol,2,4-dichlorophenol, and 2,6-dichlorophenol are the majorodor-causing species altd produce detectable odor at the 2 and3 I'g/L levels. Activated carbon is commonly used to removethese compounds and for this reason it was selected as theadsorbent. Because humic substances are also present innearly all municipal water supplies, their effect on chlorophenol adsorption was also examined.

Experimental

A high-activity bituminous-based activated carbon wasselected. It has aBET-N2 surface area of approximately 1100m2f.g and is marketed for use in water purification. (Twocompanies, Calgon Corporation and Westvaco Corporation,make carbons of this general type.) The carbon was obtainedin 12 X 40 U.S. Standard mesh size and was prepared bygrinding, sieving to yield the 60 X 80 mesh fraction, washing,and then drying to a constant weight at 120-140 °e.

2,4-Dichlorophenol (DCP), pK•.25o C ; 7.85, and 2,4,6-trichlorophenol (TCP), pK.,250C ; 6.00 (Eastman Kodak), wereused for these studies. They were analyzed using a 5750BHewlett-Packard gas chromatograph equipped with a pulsedNi6:1 electron capture detector. A 1-ft coiled glass columnpacked with 10% DEGS on 80f.100 mesh Supelcoport (Supelco,Inc.) was used for the separation of DCP and TCP. The column was conditioned for 3 h at 200°C with a carrier gas flowof 20 mL/min. Operating conditions were: column temperature, 170°C; detector temperature, 230°C; injection porttemperature, 200°C; carrier gas, dried 5% CH4-9S% Ar at 50

O.o13-936XI79/0913-0305$01.00/0 © 1979 American Chemical Society Volume 13, Number 3, March 1979 305

,<1 ,,'

~ !~

~~E

.§ .0 10)

i j

! pH ~.2 ~C pH 9.1 !38

1(;:4

ilC)4

T =2'·CD O.Cll .. po.

T : zeGe.;; 0-01 M po.

1C)~O!r-·-----L.-------,JT---------:T---~lo"

Equilibrium ConcentraTion t Ceq (moles It)

Figure 1. Adsorption isotherms for 2,4-dichlorophenol

mLimin; pulse interval, 150 ",s.2,4-Dibromophenol (DBP) (Aldrich) was selected as the

internal standard. It is eluted close to, but completely separatefrom, DCP and TCP at these operating conditions. At a givenconcentration, the detector response to it is intermediate tothe two chlorophenols and its melting point, boiling point,solubility in water, and pKa (=7.3) are very similar to the twochlorophenols. Retention times were DCP = 0.75 min, TCP= 1.35 min, and DBP = 1.85 min.

Nanograde toluene (Mallinckrodt) was used as the solventfor sample preparation, for GC analysis, and for extraction ofthe chlorophenols from aqueous solution since the solventpeak Joes not overlap with any of the peaks of interest nor arethere any interfering impurities and the partition coefficientsfor extraction of chlorophenols from water are high enoughto give adequate recovery (3).

Stock standard solutions containing 1 ",g of DBP/",L andanother containing 1 ",g of DCP and 1 ",g of TCP/",L wereprepared as outlined by the U.S. EPA (4) for organic pesticides. Working standards were prepared from the stock solution using a microsyringe and then stored at 5 ·C. Ratios ofthe peak heights of the chlorophenols to that of the internalstandard DBP were determined and plotted vs. chlorophenolconcentration to produce a standard curve for quantitativeanalysis. Day-to-day variation in detector response and column performance was significant enough that standard curveshad to be prepared prior to each set of chromatographicanalysis.

Extractions were performed using 100 mL of the adsorbatesolutions adjusted to pH 2.0 to ensure that the less solubleneutral chlorophenol species were present. Prior to extraction,0.375 ",g of DBP in distilled water was added to the solution.Extractions were performed with 5 mL of toluene resultingin a concentrating factor of 20X. The solutions were shakenfor 5 min, and 30 min was allowed for complete separation ofthe two phases. Recoveries of the chlorophenols relative toDBP were found to be loo% lilf DCP and 104% for TCP in theconcentration range studied. Absolute recovery of DBP was97%. For this procedure the estimated sensitivity limits forDCP and TCP were found to be 1 and 0.01 ",giL in water, respectively.

Three types of humic substances were used in this study:commercial humic acid (HA), supplied by Pfaltz and Bauer,fulvic acid (FA) extracted from a Finch soil using deionizedwater, and fulvic acid extracted from leaves using a pyrophosphate solution. Humic acid was separated by acidifyingto pH 1 and centrifuging. Fulvic acid was separated from thesolution by adsorption on XAD-8 macroreticular resin (Rohmand Haas) following the procedure of Leenheer and Huffman


11»)';------'-;-----....':.;-------'-;-----'~ ~

Eql,lIlibflum Concentration, C.q

(moles/J,)

Figure 2. Adsorption isotherms for 2,4,6-trichlorophenol

(5). Detailed preparation procedure and cbaracterization data,including chloroform formation potential, adsorption characteristics, functional group content, and some molecular sizedistribution data for these three materials, are presentedelsewhere (6). Residual humic acid concentration was measured using a Turner Model 110 null-balancing manuallyoperated fluorometer. Standard curves for each material wereprepared for each pH used in the adsorption analyses. A further discussion of the analytical procedures can be found inref 6.

The adsorption test solutions were prepared to tbe desiredinitial concentration of organic material and pH. A 0.01 Mphosphate buffer was used to maintain a constant pHtbroughout the test. A series of 2.5-L bottles were each filledwith 1 L of the test solution and the desired amount of carbon;the bottles were agitated vigorously for at least 12 days at roomtemperature to achieve equilibrium. Analysis of control bottleswhere no carbon was added indicated that adsorption ofchlorophenols by the glass containers was undetectable. Priorto analysis, all solutions were filtered to eliminate any carbonfmes which may have been present. The chlorophenols did notadsorb on the fiberglass filter media.


Single Solute DCP and TCP Isotherms. Single soluteisotherms for DCP and TCP at pH 5.2,7.0, and 9.1 are shownin Figures 1 and 2. At pH 5.2 and 7.0, DCP is primarily undissociated (pK" = 7.85), while at pH 9.1 it is primarily anionic. At pH 5.2, TCP is primarily undissociated (pK. = 6.0),while at pH 7.0 and 9.1 it is primarily anionic. The effect of pHon adsorption capacity for an equilibrium concentration of2 X 10-8 M chlorophenol species is shown in Figure 3. Previousstudies by Zogorski and Faust (7) for DCP near millimolarconcentration and Ward and Getzen (8) for other phenolicspecies showed that adsorption capacity rose to a maximumnear pH = pK" and fell off rapidly at pH values above the pK a.

The curve through the data in Figure 3 was drawn based onthese studies.

The results confirm findings of Gauntlett and Packham (9)in that the more highly substituted with chlorine the moleculeis, the better the adsorption of the undissociated molecule. AtpH 5.2, TCP adsorbs about three times as strongly as DCP.It should be noted that at each pH value studied 10-2 Mphosphate buffer was employed to ensure that the solutionpH would remain constant throughout the time required toreach equilibrium. Zogorski and Faust (10) reported that theadsorption of undissociated DCP is unaffected by the presenceof 5 X 10-2 M phosphates, while the equilibrium capacity ofdissociated DCP was enhanced by about 10 to 20%. Due to the

,d' -t,.K. \

,""rep,\\\\

/_---.\- -'-',,{"':P,r "K. '\,

\\

'- '-<>-

T E 28·C0.01 III PO.

C", DCP : 2 110" ..c... yep: Z 11(1"1 ..

b..-~; .-.!

o.!-----:I!--~I-_+I-_~I_~I~,

,HFigure 3. Influence of pH on chlorophenol adsorption capacity

Ceq,DCp"" 9Ceq,TCp data showed a 4-23% reduction for OCPand a 36-64% reduction for TCP (6). For these latter twoconcentration ratios, the observed surface concentrations forOCP are approximately 20-40% larger than calculated, whilethe observed and calculated values for TCP agree ratherwell.

In general, as Ceq for one species increased relative to thatfor the second species, the surface concentration of the secondspecies decreased. As the equilibrium concentration of eachspecies increases with the ratio of their concentrations remaining nearly constant, the surface concentration of OCP,which has the lower affinity for the carbon, becomes increasingly lower than the single solute surface concentration,suggesting that at the higher surface coverage the competitionis more intense. Specific reasons for the higher than expectedsurface concentrations of OCP when Ceq,DCp 2: Ceq,TCp werenot determined, but it is possible that the difference is relatedto the extent of ionization ofTCP (approximately 15% at pH5.2).

Competitive adsorption data were also measured at pH 7.At this pH, OCP is 12% anionic while TCP is 91% anionic. Thepredominant species are thus neutral OCP and anionic TCP,although significant amounts of the other two species arepresent too. The data in Table II show that when Ceq,DCp ""0.14Ceq,TCp, OCP competes more strongly with TCP than viceversa. This was even more true as Ceq,TCp decreased relativeto Ceq,DCp; the values of Xobsd for OCP were approximatelyequal to X"', whereas Xobsd for TCP was decreased to as lowas 25% of Xss' The single solute OCP isotherm is not as steepas the TCP isotherm (see Figures 1 and 2) and thus it wasexpected that OCP will compete more strongly.

The Langmuir competitive model did not predict the pH7 data very well. The model fits the OCP data fairly well at lowCeq, but not at higher Ceq values. The additional data forCeq,DCp "" 0.45Ceq,TCP and for Ceq,DCp "" 1.4Ceq,TCP show asimilar effect (6). The Langmuir model predicted much morecompetition than was observed for OCP; in some cases whereCeq,DCp> 10-6 M the observed extent of adsorption was asmuch as 200% of that predicted by the model. At high equilibrium concentrations of TCP, the observed extent of adsorption ofTCP was up to 70% less than predicted while at lowequilibrium concentrations the opposite was true (6). Instudies performed by Jain and Snoeyink (13) on neutral pnitrophenol and anionic benzenesulfonate, their model basedon some adsorption occurring without competition fit the datacollected in the concentration range 10-5 to 10-2 M well.Neither species competed with the other to a great extent.Thus, the deviations from the calculated surface concentrations which were observed for OCP can be explained if anionic

(2)

(1)Xi =

1 + t. (biCeq.i)i=l

where Xi = amount of solute adsorbed per unit weight ofadsorbent, moles/gram; X mj = surface coverage corresponding to a monolayer of adsorbate molecules on the adsorbent surface, moles/gram; b = constant related to energyof adsorption, where lib is the adsorbate concentration atwhich adsorption attains one-half of the monolayer coverage;Ceqj = equilibrium solute concentration, moles/liter; and n= number of adsorbate species. The parameters b and Xm canbe determined from the single-solute equilibrium datathrough application of the Langmuir equation (12):

1 1 1-=-+---X X m bXmCeq

As is commonly found (see ref 13, for example), the singlesolute data did not plot as a straight line in accordance withEquation 2. Accordingly, a semiempirical approach was usedto calculate the expected surface concentrations under competitive conditions. Using a computer, separate X m and bvalues were computed for each equilibrium concentrationvalue used in the competitive adsorption calculations. Thiswas done by fitting the single solute data plotted in accordancewith Equation 2 with a polynomial equation, and then determining the X m and b values for the tangent to the curvedescribed by the polynomial at each Ceq of interest. With thesevalues, Equation 1 could be used to calculate the surfaceconcentrations expected for each adsorbate, X c, as a functionof the Ceq of each adsorhate. ;

The competitive adsorption OCP-TCP equilibrium concentrations, Ceq, and Xobsd, the observed surface coverage, areshown in Tables I, II, and III with the single solute values ofX, called X", in the tables (as determined from Figures 1 and2), and X c shown for comparison. Only typical data are shown;Snoeyink et al. (6) give the data for the additional equilibriumconcentration ratios referred to below.

At pH 5.2, both OCP and TCP are primarily undissociated.Table I shows a reduction in capacity for OCP of about 3477% and for TCP of 12-27% when Ceq.TCP "" 3Ceq.DCP. Thegreater reduction in OCP capacity is consistent with thehigher equilibrium concentration ofTCP and the greater affinity ofTCP for the carbon. The calculated surface concentrations are generally very close to the observed values. Otherdata for Ceq.DCP "" Ceq.TCp showed a 6-34% reduction in capacity for OCP and a 39-47% reduction for TCP, and for

sensitivity of adsorption to pH fluctuations in the region nearthe pKa of the chlorophenols, it was felt that use of the bufferto prevent pH change was more important than the shift inadsorption capacity at a given pH because of the buffer'spresence.

Dichlorophenol and Trichlorophenol Competition.Because studies of the chlorine-phenol reaction under conditions which obtain during water treatment have shown thatmixtures of chlorophenols are likely to be present when thereare chlorophenolic odors (I, 2), an examination was made ofthe simultaneous adsorption of OCP and TCP. Three pHvalues, 5.2, 7.0, and 9.1, were used. The single-solute datashown in Figures 1 and 2, together with competitive adsorption models, were used to predict the surface concentrationof each compound when both species were present.

The most common model used to predict equilibriumconcentrations in a multisolute system is the Langmuir modelfor competitive adsorption, first developed by Butler andOckrent (11). The model permits calculation of the amountof species "j" adsorbed per unit weight of adsorbent at equilibrium concentration Ceqj in the presence of other species:

X mjbiCeqj


Table I. Chlorophenol Competition at pH 5.2 8

CeQ.DCP "" 0.35CeQ.TCP, CO•DCP = 2.70 mg/L, CO.TCP = 20.80 mg/L

2,4-Dichlorophenolbottle Ceq,DCP, molll Ceq,yep, moi/L Xobsd. mol/g XobSd' Xss Xc. mol/g XobscYXc

1 5.52 X 10-9 2.28 X 10-6 1.62 X 10-' 0.66 1.51 X 10-' 1.072 2.01 X 10-6 7.09 X 10-6 2.13 X 10-' 0.46 2.38 X 10-' 0.893 3.99 X 10-6 1.47 X 10-7 2.71 X 10-' 0.44 2.82 X 10-' 0.964 1.61 X 10-7 3.92 X 10-7 3.31 X 10-' 0.36 3.94 X 10-' 0.845 6.44 X 10-7 1.54 X 10-6 3.77 X 10-' 0.30 3.60 X 10-' 1.056 3.37 X 10-6 7.34 X 10-6 3.77 X 10-' 0.23 3.99 X 10-' 0.94

2,4,6-Trichlorophenolbotlle Ceq,yep, malll Ceq,DCP, moUl Xobsd. mol/g XobsdlXss Xc. mol/g XobscYXc

1 2.28 X 10-6 5.52 X 10-9 1.03 X 10-3 0.84 7.64 X 10-' 1.352 7.09 X 10-6 2.01 X 10-6 1.36 X 10-3 0.73 1.15 X 10-3 1.18

3 1.47 X 10-7 3.99 X 10-6 1.72 X 10-3 0.78 1.45 X 10-3 1.194 3.92 X 10-7 1.61 X 10-7 2.12 X 10-3 0.85 1.82 X 10-3 1.16

5 1.54 X 10-6 6.44 X 10-7 2.56 X 10-3 0.88 2.48 X 10-3 1.036 7.34 X 10-6 3.37 X 10-6 2.80 X 10-3 0.82 2.63 X 10-3 1.06

8 Ceq = equilibrium concentration, Co = initial concentration, X()/)$d = observed. Xc = X as calculated from Equation 1, Xss = single-solute X.

Table II. Chlorophenol Competition at pH 7.0 8

CeQ.DCP "" 0.14CeQ.TCP, CO.DCP =6.58 mg/L, CO•TCP = 10.76 mg/L

2,4-Dichlorophenolbollle Ceq,DCP, maUL Ceq,yep, mal/l Xobsch mol/g Xobsd' X.s Xc. mol/g XobsctlXc

1 5.37 X 10-9 4.25 X 10-6 4.61 X 10-' 0.85 3.99 X 10-' 1.162 1.17 X 10-6 9.62 X 10-6 5.81 X 10-' 0.84 4.64 X 10-' 1.253 2.58 X 10-6 2.15 X 10-7 7.19 X 10-' 0.82 5.22 X 10-' 1.374 6.87 X 10-6 5.19 X 10-7 8.50 X 10-' 0.77 5.77 X 10-' 1.475 2.58 X 10-7 1.65 X 10-6 1.02 X 10-3 0.74 5.39 X 10-' 1.896 1.27 X 10-6 6.58 X 10-6 1.18 X 10-3 0.69 2.54 X 10-' 4.65

2,4,6-Trichlorophenolbottle Ceq,rep, mollL Ceq,DePt mol/L Xobsd, mol/g Xobsd' X•• Xc. mollg Xobsd/Xc

1 4.25 X 10-6 5.37 X 10-9 6.22 X 10-' 0.65 4.10 X 10-' 1.522 9.62 X 10-6 1.17 X 10-6 7.83 X 10-' 0.63 6.10 X 10-' 1.283 2.15 X 10-7 2.58 X 10-6 9.67 X 10-' 0.71 8.57 X 10-' 1.134 5.19 X 10-7 6.87 X 10-6 1.14 X 10-3 0.53 1.18 X 10-3 0.975 1.65 X 10-6 2.58 X 10-7 1.34 X 10-3 0.96 1.73 X 10-3 0.786 6.58 X 10-6 1.27 X 10-6 1.45 X 10-3 0.85 2.39 X 10-3 0.61

a For definition of terms. see footnote in Table I.

Table III. Chlorophenol Competition at pH 9.1 a

CeQ.DCP "" 0.21 CeQ.TCP, CO.DCP = 7.67 mg/L, CO.TCP = 2.89 mg/L

2,4-Dichlorophenolbottle Ceq,DePt molll Ceq,yep, mol/L XObsd. mol/g XObsd'Xu Xc. mol/g XObsd' Xc

1 2.61 X 10-6 7.50 X 10-6 3.60 X 10-' 0.76 2.62 X 10-' 1.372 5.67 X 10-6 2.58 X 10-7 5.35 X 10-' 078 4.10 X 10-' 1.313 1.29 X 10-7 1.00 X 10-6 7.81 X 10-' 0.89 6.15 X 10-' 1.274 3.60 X 10-7 2.63 X 10-6 9.79 X 10-' 0.89 9,11 X 10-' 1.085 1.23 X 10-6 5.19 X 10-6 1.24 X 10-3 0.94 1.27 X 10-3 0.98

2,4,6-TrichlorophenolboUle Ceq,yep, mol/L CeQ,DCP, mol/L Xobsd, mol/g XobsdlXss Xc. mollg XObsdl Xc

1 7.50 X 10-6 2.61 X 10-6 1.11 X 10-' 0.63 1.16 X 10-' 0.962 2.58 X 10-7 5.67 X 10-6 1.64 X 10-' 0.57 1.66 X 10-' 0.993 1.00 X 10-6 1.29 X 10-7 2.27 X 10-' 0.46 2.44 X 10-' 0.934 2.63 X 10-· 3.60 X 10-7 2.52 X 10-' 0.35 2.76 X 10-' 0.915 5.19 X 10-6 1.23 X 10-6 2.56 X 10-' 0.27 1.93 X 10-' 1.32

II For definition of terms, see footnote in Table I.


Table IV. 2,4,6-Trichlorophenol Competition with Humic Substances at pH 5.2

CO.TCP = 23.80 mg/L, 10-2 Mphosphate buffer

humic substancesinitial conen, % TCP

type mg/L TOC removed 8 Ceq. mol/L Xobsd. mollg XSS' mol/g XObatY X..

commercial 10 83 4.41 X 10-7 1.50 X 10-3 2.63 X 10-3 0.57humic acid 70 5.01 X 10-· 2.32 X 10-3 3.40 X 10-3 0.68

50 66 1.08 X 10-· 1.29 X 10-3 2.68 X 10-3 0.4548 9.18 X 10-· 1.96 X 10-3 3.55 X 10-3 0.55

leaf fulvic acid 10 56 1.99 X 10-· 1.48 X 10-3 3.11 X 10-3 0.4837 1.04 X 10-5 2.21 X 10-3 3.60 X 10-3 0.61

50 28 3.80 X 10-· 1.26 X 10-3 3.31 X 10-3 0.3816 1.73 X 10-5 1.80 X 10-3 3.72 X 10-3 0.48

soil fulvic acid 10 48 8.80 X 10-7 1.50 X 10-3 2.81 X 10-3 0.5323 5.72 X 10-· 2.30 X 10-3 3.43 X 10-3 0.67

50 27 1.47 X 10-· 1.27 X 10-3 3.02 X 10-3 0.420 9.94 X 10-· 1.94 X 10-3 3.58 X 10-3 0.54

a Percent removal as measured by fluorescence at pH 5.2.

102

pH 9.1

QOI M PO,~

..ICj'!

0

i8 ui-

0

.~

IO~O., tO~'0

~

~ 1(;'.§

t TCP ~ 10' "8 11;4

jpH 5.2

0.01 " PO,

l~.

"

lCi2r-----~----~----~----__,

Equilibrium Concentration. C.q lmoles/.tl

Figure 4. Competitive adsorption capacities predicted by the Langmuirmodel for dichlorophenol at pH 5.2

Equilibrium Concenlra'iOfl. c.. (mo""')

Figure 5. Competitive adsorption capacities predicted by the Langmuirmodel for trichlorophenol at pH 9.1

TCP and neutral DCP adsorb at different sites. However, suchan explanation is not consistent with the TCP behavior; further investigation is needed to provide a satisfactory explanation.

The data for pH 9.1 in Table III are typical of those obtained by Snoeyink et al. (6) and show that anionic DCPcauses a significant reduction in surface concentration ofanionic TCP while the reverse is not true. Application of theLangmuir equation resulted in predicted values of Xc for DCPand TCP which on the average agreed rather well wi th theobserved values. Examination of all the data revealed thefollowing trend for TCP adsorption, however: when Ceq,DCI'"" 0.04Ceq,TCP, X ob,d for TCP was about 30-40% greater thanX c, whereas when Ceq,DCI' "" 0.2Ceq,TCI', X "bsd "" Xc, andwhen Ceq,DCP "" 0.45Ceq ,TCP, X obsd was 30-40% less than Xc'A similar effect for competitive adsorption of aromatic anionswas observed by Jain and Snoeyink (13), and it is consistentwith the occurrence of electrostatic repulsive forces greaterthan those which exist during single solute adsorption. As thesurface concentration of anionic DCP increases along withCeq,DCp, less TCP can be adsorbed because of the electrostaticrepulsive forces exerted by the adsorbed DCP on TCP. Examination of Figures 1 and 2 and Table 1II shows that thesurface coverage of anionic species (negative charge) is muchgreater when DCP and TCP are present than when TCP aloneis present and about. the same when DCP and TCP are presentas when DCP alone is present. The same effect on DCP ad-

sorption by TCP would not be observed because the repulsiveforce on the adsorbed DCP anion under competitive conditions is essentially the same as under single solute conditions.

Other models such as the modified Langmuir model of Jainand Snoeyink (6, 13), and the Radke-Prausnitz (14) modelwere used to determine whether any improvement in correspondence between X"hsd and Xc could be obtained. Someimprovement was seen for a few of the data, but in generalneither gave better overall results than the Langmuir competitive adsorption equation.

Using the Langmuir model and the constants obtained fromthe single solute data, families of curves showing the extentof competition at constant Ceq of competing species weregenerated. Typical sets of curves for DCP at pH 5.2 and TCPat pH 9.1 are given in Figures 4 and 5, respectively; othercurves are given elsewhere (6).

Chlorophenol-Humic Substance Competition. Datashowing the adsorption of TCP from solutions containinghumic substances at pH 5,2 and 9.1 are shown in Tables IVand V, respectively. Commercial humic acid, leaf fulvic acid,and soil fulvic acid were used. Tests at each pH were performed with two initial concentrations of humic material, 10and 50 mglL as TOe, and also with two carbon doses to obtaindifferent TCP equilibrium concentrations. Similar behavioris expected from DCP. These tests indicated that the chlorophenols were not sorbed by humic substances as is the case


Table V. 2,4,6-Trichlorophenol Competition with Humic Substances at pH 9.1

CO.TCP = 23.80 mg/L, 10-2 M phosphate buffer

humic substancesinitial conen, % TCP

type mg/L TOC removed a Ceq. mol/L Xobsd. mollg Xss' mol/g Xobsd' Xss

commercial 10 75 1.05 X 10-7 1.32 X 10-4 2.06 X 10-4 0.64humic acid 59 1.32 X 10-6 3.25 X 10-4 5.30 X 10-4 0.61

50 57 2.35 X 10-7 1.08 X 10-4 1.80 X 10-4 0.6039 2.55 X 10-6 2.45 X 10-4 6.90 X 10-4 0.36

leaf fulvic acid 10 61 1.01 X 10-7 1.30 X 10-4 2.04 X 10-4 0.6442 1.53 X 10-6 3.21 X 10-4 5.55 X 10-4 0.58

50 44 1.72 X 10-7 1.09X10-4 2.47 X 10-4 0.4422 2.25 X 10-6 2.50 X 10-4 6.40 X 10-4 0.39

soil lulvic acid 10 30 5.70 X 10-6 1.30 X 10-4 1.65 X 10-4 0.7914 8.61 X 10-7 2.35 X 10-4 4.50 X 10-4 0.74

50 21 6.58 X 10-6 1.10 X 10-4 1.76 X 10-4 0.6211 1.04 X 10-6 2.69 X 10-4 4.81 X 10-4 0.56

8 Percent removal as measured by fluorescence at pH 9.1.

for pesticides such as 2,4,5-T (I5) and other chlorinated hydrocarbons.

At pH 5.2, the presence of humic materials resulted in significant reductions in the capacity of carbon for TCP ascompared with that achieved in distilled water systems. Leaffulvic acid proved to be the most effective competitor of thethree humic substances tested while soil fulvic acid andcommercial humic acids were nearly as effective. As shown inTable IV, 10 mg/L of leaf fulvic acid reduced the carbon'scapacity at Ceq.TcP = 1.99 X 10-6 M by 52%. Increasing thefulvic acid concentration to 50 mg/L resulted in a slightlygreater reduction in capacity. Data for commercial humic andsoil fulvic acids show the same trends. A TCP equilibriumconcentration of nearly an order of magnitude higher resultedin capacity reductions which were not quite as large and alower percent removal of the humic substances.

It was expected that leaf fulvic acid and commercial humicacid would compete better with the chlorophenols than wouldsoil fulvic acid due to the better adsorbability of the former(6). Humic substance removal as measured by fluorescencewas greatest for commercial humic acid and least for soil fulvicacid. However, leaf fulvic acid was the most effective competitor while the other two materials resulted in roughlyequivalent competition. Hence, percent removal as determined by fluorescence apparently is not a good indicator ofthe ability of the humic substances tested to compete withchlorophenols. Further research is required to determine aparameter which better indicates the ability of the humicmaterials to compete with the chlorophenols.

Results for TCP competition with humic substances at pH9.1 are shown in Table V. Commercial humic acid and leaffulvic acid caused the greatest reduction in capacity for TCPwhile soil fulvic acid was not as effective. An initial concentration of 10 mg/L leaf fulvic acid reduced the carbon's capacity at Ceq.TCP = 1.01 X 10-7 M by 36%, while 50 mg/L leaffulvic acid reduced the capacity at Ceq.TCP = 1.72 X 10-7 Mby 56%. At a TCP equilibrium concentration which is higherby an order of magnitude, slightly greater reductions in capacity resulted which were unexpected. At pH 5.2, the opposite occurred, i.e., less competition was observed as the TCPequilibrium capacity was increased. The reasons for this behavior are not clear at present. Percent removal of the humicsubstances as measured by fluorescence at pH 9.1 was lowerthan those at pH 5.2 which is consistent with the higher solubility of the humic materials at high pH.

The effect of pH on the ability of the humic materials tocompete with TCP is noteworthy. At pH ,5.2 leaf fulvic acidwas the strongest competitor, while commercial humic and


soil fulvic acid resulted in nearly equal competition. At pH 9.1,commercial humic and leaf fulvic acids competed morestrongly than did soil fulvic acid. Also, the extent of compe·tition varied with pH. For example, 10 mg/L soil fulvic acidat pH 5.2 reduced the capacity for TCP at Ceq,'rcp = 8.80 X10-7 M by 47%, while at pH 9.1 the capacity at Ceq,TCP = 8.61X 10-7 M was reduced by only 26%. This can be accounted forby considering differences in adsorbabilities of soil fulvic acidat the two pH values; at pH 5.2, 48% of the soil fulvic acid wasadsorbed while at pH 9.1 only 14% was removed. Therefore,at pH 9.1 less material was competing with TCP for adsorption sites than at pH 5.2. Although more complete studies areneeded, it is expected that the different molecular size distributions and functional group makeup of the' humic materials lead to differences in adsorbabilities as a function ofpH.

Gauntlett and Packham (9) investigated the adsorption ofmonochlorophenol at the 0.1 to 1 mg/L level in the presenceof humic acid, fulvic acid, and in Thames River water. Theyshow a significant reduction in adsorption capacity of thechlorophenol (approximately 40% lower for the river water ascompared with that achieved in distilled water systems) owingto the presence of these materials, which is consistent with theresults presented in this section.

Conclusions

Chlorophenols are adsorbed very strongly by activatedcarbon at the Jlg/L level, near the threshold odor limit for thesecompounds. The extent of adsorption of DCP and TCP is animportant function of pH. The neutral species of these compounds predominate at pH below the pKa values and are adsorbed more strongly than the anionic species. As the numberof chlorine atoms substituted on the phenol increases, thesolubility of the neutral species decreases and the adsorbability increases; as substitution increases, the pKa of thespecies is lowered, however. Significant reductions in adsorption capacity (up to 75%) of one chlorophenol were causedby the presence of a second chlorophenol.

The Langmuir model for adsorption was found to be inadequate for fitting single solute adsorption data over a broadconcentration range. To obtain the Langmuir parameters, band X m, for use in the Langmuir competitive adsorptionequation, it was necessary to use the semiempirical approachof calculating them at each equilibrium concentration of interest. Competitive adsorption studies between DCP and TCPresulted in verification of the applicability of the Langmuircompetitive adsorption equation at pH 5.2 and 9.1. At pH 7.0,where neutral and anionic DCP compete with neutral and

anionic TCP, the fit of the data was not completely satisfactory.

According to the Langmuir theory of adsorption, the parameter b (see Equations 1 and 2) should be constant. In thiscase the term (k :'=. biCi) in the denominator of Equation 1should be much less than unity at very low concentration andadsorption should take place without competition. However,this was not the case at pH 5.2, 7.0, and 9.1. In all instances,the term (b,C, +b2C2) was significant relative to unity; as thevalue of Ci decreases, the corresponding value of bi increasescausing the entire denominator in Equation 1 to remaingreater than unity. The parameter b is proportional toexp(-fV{/RT) where!1H is the adsorption energy. Adsorptionenergy varies with surface coverage; high-energy sites areoccupied first with subsequent adsorption occurring at increasingly lower energy sites as the surface coverage increases.The net result is significant competition between sorbateseven at very low concentration.

Evaluation of the competitive effects of commercial HA,soil FA, and leaf FA showed that the presence of these materials decreased the capacity of carbon' for chlorophenol too,and that each of the materials competed somewhat differently.

When the findings on competitive adsorption betweenchlorophenols and humic substances are considered, it is apparent that any testing to determine the best carbon and design criteria for a given application should be done using thespecific water to be treated. Such factors as the nature andconcentration of competing organic materials and the pH,among others, playa major role in determining the removalone can expect of a certain component.

Acknowledgment

The assistance of P. Boening, J. McCreary, and N. Woodwith portions of this study is also acknowledged.

Literature Cited

(1) Burtschell, R. H., Rosen, A. A., Middleton, F. M., Ettinger, M. B.,J. Am. Water Works Assoc.• 51,205-14 (1959).

(2) Lee, G. F., in "Principles and Applications of Water Chemistry",Faust, S. J., and Hunter, .J. V., Eds., Wiley, New York, N.Y.,1967.

(3) Korenman, Y., J. Appt. Chem. USSR (En"l. Transt.), 47,2134-7(1974).

(4) U.S. Environmental Protection Agency, "Methods for OrganicPesticides in Water and Wastewater", National EnvironmentalResearch Center, Cincinnati, Ohio, 1971.

(5) Leenheer, J. A., Huffman, E. W. D.,Jr., J. Res. US. Geol. Suro.,4,737-45 (1976).

(6) Snoeyink, V. L., McCreary, J. ,J., Murin, C..J., "Activated CarbonAdsorption of Trace Organic Compounds", Report EPA-600/277-223, U.S. Environmental Protection Agency, Cincinnati, Ohio,1977.

(7) Zagorski, J. S., Faust, S. D., "Removal of Phenols from PollutedWaters", New Jersey Water Resources Research Institute, RutgersUniversity, 1974.

(8) Ward, T. M., Getzen, F. W., Environ. Sci. Tedmol., 4, 64-7(1970).

(9) Gauntlett, R. B., Packham, R. F., in Proc. Conference on Activated Carbon in Water Treatment, University of Reading, WaterResearch Association, Medmenham. England, 1973.

(10) Zogorski, ,J. S., Faust, S. D., J. Environ. Sci. Hl'<llih. All(S &9),501-15 (1976).

(11) Butler, J. A. V., Ockrent, C., J. Phys. Ch,'m.. 34, 2841-59(1930).

(12) Langmuir, I. J. Am. Chem. Soc., 40, 1:J6l-40:1 (1918).(13) Jain, J. S., Snoeyink, V. L., J. Water Pvllul. Conlrol Fed., 45,

2463-79 (1973).(14) Radke, C. J., Prausnitz, J. M., AfChE J. 18,761-8 (1972).(15) Wershaw, R. L., Burcar, P. ,I., Goldberg, M. C., Environ. Sci.

Technol., 3, 271-:\ (1969).

Received for review April 17. 1978. Accepted October 3. 1978. Thepartial suppvrt of the EPA, Grant No. R803473. for this study isgratefully acknowledged. The contents do not necessarily reflect theviews and policies of the EPA, however, and the mention of tradenames and commercial products doe8 not constitute endorsement.

Growth and Element Uptake of Woody Plants on Fly Ash

David H. Scanlon" and J, Carroll Duggan'

Division of Forestry, Fisheries, and Wildlife Development, Tennessee Valley Authority, Norris, Tenn. 37828

• Pulverized coal ash stored at the John Sevier Power Plant,Rogersville, Tenn., was tested as a substrate for eight woodyplant species. Concentrations of As, B, Cd, Cr, Cu, Hg, K, N,Ni, P, Pb, Se, and Zn were measured in plant foliage in thesecond and third growing seasons on fly ash and a soil control,and were compared with concurrent analyses of the substrates.B, Ni, and Se appeared more available to plants of all specieswhen grown on fly ash, while uptake of As and Hg varied byspecies. Cr and Pb showed no increases in foliar concentrationin plants grown on fly ash as compared with soil. Mean survival of plants on fly ash was 53%, ranging from 12 to 84%depending on species. Application of 10 cm of subsoil over thefly ash resulted in no improvement in plant performance.Nitrogen-fixing species appeared best adapted for use in flyash stabilization.

Difficulties in disposal of fly ash resulting from pulverizedcoal combustion at electric power plants are of increasingconcern. About 62 million tons of fly ash were collected in the

I Present address, Tennessee Valley Authority, Division of EnergyResearch, Chattanooga, Tenn. 37401.

United States in 1976 (J), up from 40 million in 1974 (2), andwith a renewed emphasis on coal utilization, collections mayincrease rapidly during the next decade.

While approximately 20% of the fly ash collected in 1976was utilized (J), mostly in concrete, asphalt products, and roadstabilization, the r6mainder was stored in dewatering pondsor landfills. Ash placed in disposal areas must be stabilizedand covered to prevent wind and water erosion and concomitant environmental problems.

Establishment of vegetation is often an effective means ofstabilizing solid wastes. However, a review of the literaturereveals relatively few studies dealing with establishment ofvegetation directly on fly ash and information on plant growthand chemical relationships on the substrate is limited. Differences in response have been reported for plant speciesgrowing on fly ash as with the plant Atriplex hastata var.deltoidea which was observed to rapidly colonize on bare ashwhere other species failed (3). When Atriplex was comparedin ash pot culture studies with barley (Hordeum vulgare), onlythe barley exhibited numerous element toxicity symptoms (3).Yellow sweet clover (Melilotus officinalis), observed vigorously growing on landfilled fly ash with a pH of 4.5, wascompared with clover grown on an isolated gravel bank andfound to have higher concentrations of most elements ana-

This article nol subject to U.S. Copyright. Published 1979 American Chemical Society Volume 13, Number 3. March 1979 311

Table I. Composition of John Sevier Fly Ash inDisposal Area at Initiation of Test a

major element dry wt. % major element drywt, %

Si02 52.8 Na20 0.3AI203 26.8 K20 2.9Fe203 12.7 Ti02 1.4CaO 1.4 S03 0.9MgO 1.2

a Loss on ignition, 5.2%; pH 5.6 (range 4.0-7.6); fineness, % through 16mesh,82.

Iyzed (4). Tall fescue (Festuca arundinacea cv. Ky. 31) andwhite sweet clover (Melilotus alba) were grown successfullyon fly ash of pH ranging from 6.5 to 7.5 (5). Other herbaceousplant studies have involved the effect of fly ash used as a soilamendment on plant toxicity and element uptake in tests ofagricultural crops including cabbage (Hrassica oleracea) (6),alfalfa (Medicago sativa) and corn (Zea mays) (7), barley,heets (Heta vulgaris), and kale (Brassica oleracea acephala)(8)

Using woody plants, 19 species were tested in pots using twotypes of fly ash and only boxelder (Acer negundo), green ash(Fraxinus pennsylvanica var. lanceolata), and white poplar(Populus alba) resulted in good survival and growth (9). European black alder (Alnus glutinosa) and Virginia pine (Pinusvirginiana) were successfully established on a dewateredsettling pond of pH 6.5 to 7.5 fly ash, although initial pinegrowth was much slower than the alder (4). On 12-year-old,sluiced bottom ashes (pH 8.9-9.2), planted loblolly pine(Pinus taeda), sycamore (Platanus occidentalis), andsweetgum (Liquidambar styraciflua) had good survival, andtissue analyses indicated no element toxicity problems(10)

Although the above work demonstrates the feasibility ofestablishing some species directly on fly ash, information isneeded on species variability in growth and toxic elementuptake on different types of fly ash. Therefore, this study wasundertaken to evaluate the performance of eight species oftrees and shrubs planted in acidic fly ash in a dewatered disposal area. Concurrent analyses of metallic elements and plantnutrients were made on the fly ash and plants growing thereonto determine trends in uptake and possible toxic effects on theplants.

Experimental

TVA's John Sevier Steam Plant is located in eastern Tennessee on the south bank of the Holston River 5 km southeastof Rogersville. Fly ash produced there is sluiced into settlingponds approximately 300 m from the plant. The experimentalsite is located on a north-facing, 20% slope of mounded ash ina completed section of the disposal area. An analysis of themajor elements in the ash as sampled just prior to plot establishment is shown in Table I.

The experimental design included four adjoining 24.4 m X48.8 m blocks on the slope of mounded fly ash, with two blockslocated in upslope positions and two on the lower slope. AlO-cm cover of gravelly clay subsoil was applied on two blocks,one in each of the slope positions. In eacb of the four blocks,16 seedlings from each of 8 woody plant species were randomized in four, four-plant replications using 3 m X 3 mspacing. A fifth block planted as an experimental control waslocated 200 m away on a graded and turfed area developed ona level subsoil fill of gravelly clay loam with a pH of 7.4.

The species tested included European black alder (Alnusglutinosa), sweet birch (Betula lenta), sycamore (Platanusoccidentalis), sawtooth oak (Quercus acutissima), cberry


olive (Elaeagnus multiflora ovata), autumn olive (E. umbellata), silky dogwood (Comus amomum), and gray dogwood(C. racemosa). These were selected for their general abilityto grow under adverse conditions and provide wildlife habitatand aesthetic improvement. One-year-old seedlings weregrown in the TVA Norris nursery and bare rooted plants werehand planted in early April 1975. During the previous fall theexperimental blocks were seeded with tall fescue, ryegrass(Lolium perenne), yellow sweet clover, and sericea lespedeza(Lespedeza sericea), fertilized with 200 kglha of 10-10-10, andmulched with oat (Avena sativa) straw to provide initialerosion control.

Evaluations of the test were made following the second andthird growing seasons. Survival percentages and total heightswere recorded to evaluate establishment success and weretested by analysis of variance. Foliage samples were collectedin 1976 and 1977 during the last week in August. Small sizesof the plants and some low survival made it necessary tocombine samples from the replicates which precluded analysisof variance tests. Samples were taken from the dominantshoots of all surviving plants of a species in a given block usingfully developed leaves. Foliage samples were washed, thoroughly mixed, dried in a forced air oven at 40°C for 13 h, andfinally milled to pass through a 2-mm screen.

Samples of fly ash and also subsoil from the control plotwere collected concurrently with the foliage samples using foursubsampies per test block. On the two blocks with 10 cm ofsubsoil covering the fly ash, the soil was scraped away topermit collection of ash samples below. All collections weremade at a depth of about 15 cm. Samples were dried in aforced air oven at 40°C and then screened through a 16 mesbbefore analysis.

In the third growing season, fruits were produced by onlythe European black alder, cherry olive, and autumn olive, butonly cherry olive in block 4 was in sufficient quantity to provide a sample for chemical analysis. Fruits were prepared foranalysis by removing the seeds before drying and milling.

All samples were analyzed by the Analytical Laboratory inthe Fundamental Research Branch of TVA. Arsenic was distilled as AsCh and determined spectrophotometrically as theheteropoly blue complex. Boron was determined spectrometrically by the azomethine-H procedure as proposed by Wolf(11). Selenium was determined fluorometrically using thereagent 2,:J-diaminonaphthalene and the method proposedby Ihnat (l2). A modified version of tbe vanadomolybdatemethod as described by AOAC (13) was used to determinepbosphate. Flame atomic emission spectrometry was used todetermine potassium. Cadmium, chromium, copper, nickel,lead, and zinc were determined by atomic absorption spectrometry by flame or graphite furnace atomization accordingto the methods described by the instrument manufacturer(l4). Mercury was determined by flameless atomic absorptionspectrometry according to Hatch and Ott (15) after digestionof the samples following the techniques suggested by Barrett(16)

Results

At the end of three growing seasons approximately half theshrub and tree seedlings planted on fly ash were living. TableII presents the survival percentages by species and treatment.Analysis of variance showed highly significant differencesamong species and among treatments. Two Elaeagnus species,cherry olive and autumn olive, had the best survival followedby sawtooth oak and the shrub dogwoods. Survival of sycamore and European alder was moderate to low on the four flyash blocks while most sweet birch failed "to survive on subsoilor fly ash.

Comparison of treatments shows no overall improvement

Table II, Mean Percentage Survival after Three Growing Seasons

plants grown on fly ash disposal areaerrect of soil cover a effect of slope location a

without 10-cm cover upslope downslope

all lest plants a

fly ash area control areafly ash substr. soli substr.

cherry olive 91 78 ns 69 100' 84 100'

autumn olive 84 72 ns 62 94 ns 78 88 nssawtooth oak 62 66 ns 38 91' 64 62 nssilky dogwood 62 53 ns 44 72 ns 58 81'

gray dogwood 62 50 ns 47 66 ns 56 69 nssycamore 28 56 ns 19 66' 42 62 nsEuropean alder 28 38 ns 19 47 ns 33 38 nssweet birch 9 16 ns 6 19 ns 12 12 ns

a "r· test results indicated as: •. significance at 5% level; ns. not significant at 5% level.

Table III. Mean Total Heights in Centimeters after Three Growing Seasons

plants grown on fly ash disposal area all test plants aeflect of soil cover a eflect of slope location a fly ash area control area

without 10-cm cover upslope downslope fly ash substr. soil substr.

European alder 214 197 ns 195 210 ns 206 338 nscherry olive 234 176' 172 238' 205 220 nsautumn olive 185 160 ns 172 176 ns 174 145'

sycamore 55 91 ns 85 68 ns 74 141'

silky dogwood 56 80 ns 61 70 ns 66 135'

gray dogwood 49 54 ns 51 51 ns 51 135'

sawtooth oak 64 62 ns 61 60 ns 60 74 nssweet birch 66 80 ns 51 88 ns 73 77 ns

a ""'test results indicated as: ., significance at 5% level; ns, not significant at 5% level.

in plant survival by the addition of 10 cm of suhsoil over flyash. Upslope and downslope locations had more impact onsurvival than subsoil cover. Initially bigh acidic (pH 4.0)conditions and greater moisture stresses of the upslope blockslikely were responsible for higher mortalities there.

Mean total heights attained by the eight species in 3 yearsare sbown in Table Ill. All species, hut particularly the shrubdogwoods and sycamore, showed stem dieback and sproutingunder the extreme conditions of moisture stress and winterseverity experienced during the test period. Therefore, heightswere measured on the dominant leader or sprout of each plant.Vigorous initial height growth appeared to give some speciesan advant.age in competition with groundcover species, andthus the alder, cherry olive. and autumn olive showed bettergrowth on fly ash than the other species. Analysis of varianceshowed height differences among species to be highly significant while treatment effect., on total heights were not statistically significant.

Results of elemental analysis of fly ash, subsoil, and foliageof seven plant species are presented in Table IV. Althoughanalyses of fly ash and fly ash grown foliage were determinedfor each of four treatment blocks, differences among blockswere relatively small so results shown are means of four blocks.In comparisons of the elements in fly ash and subsoil substrate, it is notable that all elements except zinc analyzedconsistently higher in fly ash. The followup analyses of fly ashshowed decreased contents of As, B, Cu, Hg, Pb, and Se whileCd, Cr, 1<, Ni, P, and Zn increased.

Foliar analyses indicated substantially elevated levels ofB, Ni, and Se for all seven species grown in fly ash. Increasedlevels of As were detected only in sycamore and silky dogwood,while Cr and Pb showed no increases in plants grown on flyash. There appeared to be some accumulation of Hg in planttissue and levels were slightly higher in fly ash grown plants.Levels of Cd, Cu, and Zn generally were comparatively higherin foliage from fly asb tban from subsoil. Most notable in thefoliar comparisons are the higb accumulations of Band Se intissue grown on fly asb.

Results of the one fruit analysis of cberry olive from fly ashblock 4 (Table V) indicate levels of As, B, Hg, Ni, Pb, and Sein fruit to be lower than those in comparable leaf tissue. Levelsof Cd, Cr, and Cu were slightly increased in fruit, while Znlevels were the same.

Di"cu.~sion

Experimental results indicate that two Elaeagnus species,autumn olive and cherry olive, can be successfully establishedon acidic to neutral fly asb disposal areas. These species appeared exceptionally adaptable to adverse site conditions andgenerally showed no visual toxicity or element imbalancesymptoms. European black alder showed rapid growth afterrather poor survival. This species appeared more site selectiveand sensitive to moisture 'stress, since an earlier study (4)showed good survival of alder on a level ash pond site. However, because it is a soil nitrogen-fixer like the Elaeagnusspecies, European black alder should be strongly consideredfor inclusion in shrub and tree mixtures planted on ash disposal sites. Sawtooth oak survived well although, typical ofoak species, early growth has been slow. Further growthevaluations are required, but conditionally the species appearsto have potential on acid to neutral fly ash. Sycamore and theshrub dogwoods showed fair to moderate survival but alsodieback and poor early growth. Although evaluations ofgrowth must be continued, the inclusion of sycamore, whichperformed well on alkaline ash (10), and silky dogwood, themore site-flexible species, appears warranted on a trial basis.Sweet birch, though an invader on coal strip mines, was foundunsuitable for establishment on fly ash.

The application of 10 cm of subsoil to fly ash before revegetation appeared to reduce wind erosion but did not significantly improve survival or growth of woody plants. Growthof herbaceous vegetation on the subsoil-covered blocks showedno improvement over that on fly ash; however, the subsoil usedas cover was relatively heavy and infertile. If a good qualitytopsoil had been available and used, herbaceous and possiblywoody vegetation on the treated blocks might have shown


Table IV. Elements in Foliage of Woody Plants in Second and Third Seasons on Fly Ash and Subsoil(Parts per Million)

subsoil lIy ash II subsoil fly ash IIelement 2nd 3,d 2nd 3rd 2nd 3rd 2nd 3,d

growth media European alder

As 6 6 49 42 4 2 4 2.5B 70 60 98 72 140 120 695 306Cd <1 1.6 1.5 2.0 <0.3 0.1 <0.3 0.1Cr 50 70 128 152 6 0.9 6 0.9Cu 60 50 182 152 20 10 28 14Hg 0.11 0.06 0.28 0.11 <0.01 0.8 <0.01 0.8Ni 30 50 90 145 5 9 19 15Pb 20 40 68 60 4 4 4 4Se 0.9 0.8 1.8 1.6 0.3 0.2 11.6 1.9Zn 80 110 95 102 36 26 56 50N 21700 21600 28075 25100P 1 100 700 1475 1550 1200 1200 1675 1475K 18700 21000 21050 22300 6400 5400 8000 7150

autumn olive cherry oliveAs <1 2 1.2 1.8 1 1 1.5 2B 120 120 472 168 140 170 560 342Cd <03 0.3 <0.3 0.4 <03 02 <0.3 0.4Cr 2 0.8 2.5 1.0 4 0.6 2.8 0.6Cu 18 13 30 32 12 10 16 14Hg <0.01 1.6 <0.01 2.1 <0.01 1.3 <0.01 1.4Ni 5 6 12 15 6 6 12 14Pb 5 5 4 5 4 3 4 4Se <0.1 0.2 3.7 1.1 0.3 0.2 1.6 0.6Zn 32 15 32 60 21 10 22 24N 38700 41800 42200 41350 2600 34800 29250 27850P 2100 2100 2650 2350 1800 1900 1875 1775K 10000 10300 11475 12050 9000 10000 8350 8225

sycamore sawtooth oakAs <1 1 5.8 2.3 1 2 2 2B 100 70 580 190 150 100 605 282Cd <0.3 0.1 <0.3 0.2 <0.3 0.1 <0.3 0.2Cr 1 0.3 2 0.5 4 0.5 2.5 1Cu 18 11 23 16 15 22 16 12Hg <0.01 0.7 <0.01 0.8 <0.01 1.0 <0.01 0.8Ni 3 5 11 12 6 5 9 10Pb 2 3 2 3 4 4 5 4Se 0.3 0.3 9.8 1.9 0.3 0.3 2.0 1.4Zn 22 7 14 7 32 34 28 24N 14000 13900 12800 14775 12900 19200 14075 18400P 1600 2300 1900 2525 1600 2000 1700 2100K 9200 8700 10525 10525 8400 7400 9750 9025

silky dogwood gray dogwoodAs <1 1 1.3 2.3 3 1 3 2B 100 70 483 152 120 110 640 212Cd <0.3 0.1 <0.3 0.2 <0.3 0.3 <0.3 0.2Cr 3 0.6 2.3 0.4 4 0.7 3 0.8Cu 9 8 14 11 11 9 11 16Hg <0.01 0.3 <0.01 1.0 <0.01 0.8 <0.01Ni 8 4 16 9 11 6 21 10Pb 4 5 4 4 5 4 4 4Se 0.4 0.3 2.1 1.3 0.4 0.2 4 1.6Zn 33 13 25 12 36 10 18 18N 10100 10000 10367 15175 12800 12900 12050 17 650P 1900 2800 2100 2950 4100 4500 3050 3425K 7600 7400 7667 10350 10000 10300 10050 11525

a All fly ash values are means of four treatment blocks on ash pond. b Insufficient sample to run analysis.


Table V. Element Content of Fruit of Cherry OliveCompared with Foliage and Fly Ash Substrate

3rd-year cherryfly ash, olive. ppm

element ppm fruit foliage

As 37 1 28 80 30 290Cd 2.1 0.5 0.3Cr 150 1.2 0.7Cu 150 19 17Hg 0.08 <0.1 0.6Ni 140 9 12Pb 50 3 4Se 1.6 0.7 0.8Zn 90 16 16N 22500 33500P 1600 1900 1800K 21400 9700 6900

slight improvement, but it is unlikely that topsoiling wouldbe cost-effective.

Interactions of trace metals in plants and substrates, andespecially industrial products like fly ash, are exceedinglycomplex and difficult to interpret and predict. Though element uptake, particularly toxic metals, in agricultural cropsgrown on waste materials is of primary importance, consideration also must be given to the eventuality of increasedmetals in natural food chains. Analyses in this study weremade primarily to illustrate trends of trace element movementfrom fly ash into woody plant foliage. High accumulations ofselenium found in the seven woody plants are in accord withfindings using yellow sweet clover (3) and cabbage (6) andillustrate a need to study the protective complexing of heavymetals by selenium (I7). Boron accumulation in the woodyplants was very high, but the toxicity symptoms that havebeen noted in agricultural crops on fly ash (7) were not observed. The elevated levels of nickel found in all seven speciesgrown on fly ash were probably influenced by the elementavailability from surface desorption in the low pH ash (I8)although similar consistent responses in arsenic and cadmiumwere not evident. Lead and chromium showed no increase inuptake on fly ash grown woody plants illustrating that theseelements are fixed in fly ash in unavailable forms as in soils(6). Mercury showed low level accumulations in the foliage oftested species '~nd was significantly higher after the third yeargrowth compared to the second year for some unexplainedreason. Analysis of mercury in the single sample of fruit from

cherry olive grown in fly ash showed a much lower concentration than in comparable foliage.

The effect of l1y ash grown fruit or foliage intake on wildlifesuch as songbirds, rabbits, or deer has yet to be investigated.However, one study of this type (3) involving guinea pigs fedl1y ash grown sweet clover exclusively for·90 days showed nodetectable toxicologic effects. Of 35 elements investigated,only selenium and rubidium were consistently higher in allanalyzed tissues of the test animals. Additional similar studieswill be required to follow and evaluate the effect of trace elements from land-disposed wastes, like fly ash, in natural foodchains.

Since fly ash from different locations varies substantiallyin pH and element content, a number of studies likely will beneeded to determine adequate vegetation requirements forstabilization. Through interdisciplinary and interagency cooperative approaches the necessary information on vegetativeneeds and elemental movement might be most efficientlyobtained.

Literature Cited

(1) National Ash Assoc. and Edison Electric [nst., Ash at Work, 9(6),1 (1977).

(2) National Ash Assoc. and Edison Electric lnst., ibid., 7(3), 1(1975).

(3) Rees, W. ,J., Sidrak, G. H., Nature (London), 176,352 (1955).(4) Furr, A. K., Stoewsand, G. S., Bache, C. A., Guttenmann, W. A.,

Arch. Environ. Health, 30,244-8 (1975).(5) Duggan, J. C., Scanlon, D. H., Compost Sci., 150), 26-30

(974).(6) Furr, A. K., Parkinson, T. F., Hinricks, R A., Van Campen, D. R,

Bache, C. A., Gutenmann, W. A., St. John, L. E., Jr., Pakkala, I. S.,Lisk, D. ,J., Environ. Sci. Techno!., 11,1194-1201 (977).

(7) Martens, D. C., Compost Sci., 12(6),15-9 (1971).(8) Holiday, R., Hodgson, D. R, Townsend, W. N., Wood, J. W.,

Nature (London), 181,1079-80 (958),(9) Kluczynski, 8., Folia For. Put., 21,79-103 (1973).(10) Horton, ,J. H., McMinn, J. W., "Ash Basin Reclamation with

Forest Trees", ERDA-DP-1477, 1977.(l I) Wolf, R., Soit Sci. Plant Anat., 2(5),363-74 (1971).(12) Ihnat, M., J. A,,"uc. Off. Ana!. Chern., .>7(2),368-72 (1974).O:l) Assoc. Off. Anal. Chern., "Official Methods of Analysis", 12th

ed., 2.044, p 14. 1975.(4) [nstrumentation Laboratory, [nc., "Procedure Manual for

Atomic Absorption Spectrophotometry", 1971.(15) Hatch, W. R, Ott, W. L., Anal. Chern., 40(14), 2085-7 (1968).(16) Barrett, F. P., Analyst, 81(962),294-8 (956).(17) Ganther, H. E., Wagner, P. A., Sunde, M. L., Hoekstra, W. G.,

Trace Subs!. Environ. Health, 5, Proc.. Uniu. Mo. Annu. Conf., 6th,1972,6,247-52 (197:J)

(L8) Theis, 1'. L., Wirth, J. L., Enuiron. Sci. Technol., LI, 1096-1100(1977).

Received for revicl/' May 15, 197R. Accepted October 4, 1978.

Impingement Sampling Frequency. A Multiple Population Approach

Farouk M. EI-Shamy1

Lawler, Matusky & Skelly Engineers, 415 Route 303, Tappan, N.Y. 10983

Impingement of fish on the intake screens of power plantshas become a problem for regulatory agencies, hiologists, andthe electric utility industry. The goal of impingement programs currently being conducted at power plants is to document the numbers of fish killed at the cooling water intakesregardless of the significance of each species. Although thereare no nationwide guidelines for impingement studies, in May

, Present address, 4624 Old William Penn Highway, Monroeville,Pa. 15L46.

1976, the EPA released the second draft of an impingementand entrainment (316-b) guidance manual (1) which may bepublished soon. The proposed guideline states that if impinged fish cannot be counted daily, then sampling is to bedone once every 4 days for 1 year.

As this paper will show, sampling once every 4 daysthroughout the year is not always appropriate. Sampling fishcommunities at equal Lime intervals means all species aretreated equally. Whether the species is scarce, absent, orabundant, there is no difference in the sampling efforts. All

0013-936X/79/0913-0315$01.00/0 © 1979 American Chemical Society Volume 13, Number 3, March 1979 315

• Two years of impingement data were analyzed to designa sampling program based on the optimum allocation method.The method was applied to all species combined and thenseparately to each species. By sampling most intensivelyduring months of peak fish abundance, a more precise estimate of yearly impingement rate was possible than whensampling was evenly distributed throughout the year. A 25%reduction in the current annual sampling program, whenreallocated, decreased the width of 95% confidence intervals

for the mean number of fish impinged daily. This width decreased from the original ± 15.8% to ±4% for all fish combined,from ±32% to ±7% for alewife, from ±41% to ±17%for whiteperch, and from ±16% to ±11% for rainbow smelt. An improvement in precision of estimation was also predicted forother species. The analyses presented here suggest that, foreach representative species, a different sampling scheme isnecessary unless the "species of interest" concept is ignored.

where ni = the sample size to be taken in month i, n, = thetotal number of samples to be taken from all strata, Ni = thenumber of days in month i, and Si = the standard deviationin month i, obtained from historical data.

randomized sampling efforts in proportion to the historicalvariance in the impingement rate for the monthly stratum.The method is used to predict the sample size needed to estimate mean impingement rate with predetermined confidence limits based on the variability associated with previousdata collections (4). The procedure is performed on severalspecies separately. The method is applied to determine theprecision of the current program based on an average of 16424-h samples taken annually, the precision achievable byreallocating the current sample size using the optimum approach, and the precision achievable with 25% reduction inthe current efforts using the optimum approach.

The impingement data collected at the Nine Mile Pointplant exhibit seasonal cycles in the presence of all species.Stratification of the data results in mean impingement ratesfor each stratum which describe the mean seasonal cycles. Thenumber of samples specified for each stratum by the optimumallocation technique is determined by the size of the stratum(number of days in the month) and the variance within it; alarge stratum and a stratum with a larger variance will bothrequire a larger number of observations than a smaller stratumor one with less variance (3).

The differences in both numbers and species compositionfrom month to month and the conventional monthly form ofdata summaries suggest the use of monthly strata. Thus, asample size is allocated to each stratum separately accordingto the following equation:

species are of interest to the ecosystem; however, certainspecies are more important than others and consequentlyshould be emphasized in the sampling scheme. Further, if asampling program is designed to account for a total numberof fish killed annually, it may be possible to gain more preciseinformation at lower cost by using a sampling scheme differentfrom that suggested by the EPA, particularly if guided by factsalready known about the water body in question.

The primary goal of this paper is to determine a samplingprocedure which increases the precision of estimates of theannual average number of "important" fish species impingedper day and to determine a sampling scheme for estimatingmore precisely the annual fish mortality for all species combined for the same or less effort and cost than that recommended by the EPA and than that currently being practiced.

Experimental

The Data Set. Sampling was conducted at the Nine MilePoint Nuclear Station Unit 1 on the southeastern shore ofLake Ontario in the town of Scriba (near Oswego), N.Y. Theunit has been in operation since December 1969 and uses aonce-through cooling system. Water circulation, intakestructure, and mode of operation are described in ref. 2, whichalso includes a detailed description of sampling locations andcollections procedures.

Impingement collections used for this study were mariefrom January 1974 through December 1975. A 24-h saml-lewas collected three times per week. During periods of heavyimpingement (more than 20000 fish/24 h), the sampling wasdaily. Daily sampling was continued until the number of fishcollected dropped below 20000 fish/day. All fish collectedwere identified to species and counted.

Stratification and Optimum Allocation. To determineappropriate sample size, the stratification and optimum allocation approach (3-5) was used. This approach allocates

NiSini=nt--

12L: NiSi

;=1

(1)

Table I. Estimated Total Number of Fish Collected Monthly in 1974 and 1975 by the Current Program

January February March April May Junespecies 1974 1975 1974 1975 1974 1975 1974 1975 1974 1975 1974 1975

alewife 305 3258 165 748 435 5186 63825 206179 768058 127093 66867 27807rainbow smelt 4324 3276 3523 2746 6716 3438 8424 20444 14698 1985 1333 279three5pine

stickleback 133 332 438 2155 2354 7757 734 41758 1471 1366 514 242white perch 147 126 639 313 2407 186 1 516 642 140 65 10 10smallmouth bass 18 5 26 5 14 3 12 2 61 8 21 9spotlail shiner 48 35 53 58 204 44 199 184 455 40 109 59yellow perch 89 71 125 109 90 58 77 81 59 17 12 16salmon ids a 2 8 0 18 1 11 0 24 0 3 0 1other species 962 772 2089 856 4557 727 1273 1882 2212 637 337 169

total 6028 7883 7058 7008 16778 17 410 76060 271196 787 154 131214 69203 28592

a Represented by seven species combined; see text.


(3)

(2)

The optimum allocation equation assumes that the population being sampled is finite. Occasionally, the number ofsamples ni to be taken in month i exceeds the number of daysin that month. When this occurs, each day in the month mustbe sampled and the remaining number of samples (n, - ni)must be assigned to the remaining months.

The population standard error (Si) is related to themonthly variances from historical data by the equation:

./li-12 s·2S-=V- L N(N-n)-"-

x N2 i=1 I I I nj

where N = all possible days to be sampled in a year, Si 2 = thesample variance in month i, Ni = the number of days in monthi, and Si 2 = ~iJ,1 (Yij - y;J2/(ni - 1).

The monthly standard error is estimated based on the finitepopulation equation:

51. = V(1 _nil Si 2

I N j nj

where 51, = standard error in month i.

Results

Abundance and Species Composition. A total of 48species were identified in the 2 years of collection. Threespecies-alewife (A/osa pseudoharengusJ, rainbow smelt(Osmerus mordax), and threespine stickleback (Gasterosteusacu/eatus)-made up more than 95% of all fish impinged in1974 and 1975 (Table I) on an annual basis. These threespecies, together with smallmouth bass (Micropterus dolomieui), white perch (Morone americana), spottail shiner(Notropis hudsonius), yellow perch (Perca flavescensJ, andtwo species of salmonids (brown trout and coho salmon), wererecognized by the EPA (Region II) as representative important species of the southern region of Lake Ontario. Browntrout and coho salmon were very few in number and thus werecombined with cisco, lake trout, chinook salmon, brook trout,and rainbow trout and included in the analysis of samplingfrequency for all salmonids.

Alewife. The annual mean number of alewife impinged in1974-1975 was estimated to be 4104 fish/day ± 1317 at the95% confidence level assuming independent random sampling(Table II). The precision varied widely between months sincemonths were sampled nearly equally, but the monthly variances were not equaL For example, the precision in May (whenthe vast majority of alewife were impinged) was relatively poordue to the high variances in the impingement rate. Evidentlymore samples were needed in May. Conversely, in October theprecision was much higher; the average number of alewifeimpinged was only 395 fish/day. Based on the current pro-

gram, the precision of the annual mean with 95% confidenceinterval was 32%.

If the 2-year data base accurately describes the variance inthe monthly strata, allocation of the current sampling efforts(164 days) to the 12 monthly strata, using the optimum allocation technique, results in a predicted annual mean impingement (number/day) of 4104 ± 150 fish at 95% confidence(Table 11). The number of samples needed in April, May, andAugust exceeds the number of days in these months, resultingin the theoretical optimum not being realized because Equation 1assumes that samples are independent of each other andno bounds are placed on the sample size. April, May, andAugust are assigned 30, 31, and 31 sampling days, respectively,coinciding with the finding that the majority of alewife (TableI) are impinged in these 3 months. The remaining samplingeffort (72 days) is redistributed to the rest of the months according to their variances.

Rainbow Smelt. An estimate of the precision of the currentprogram, together with the precision based on the use of theallocation approach, is listed in Table III. The annual meannumber (number/day) of rainbow smelt estimated from the1974-1975 program was 213 ± 34 fish/day (Table Ill).

As in the case of alewife, if the optimum allocation methodis used, the number of samples needed in certain months(March, April, and May) exceeds the number of days in eachmonth. Most rainbow smelt were impinged in these months(Table I) and large variance was observed. Thus, larger samples are specified for this period. The optimum allocation,when applied to 164 samples annually, results in a precisionof 5% of the annual mean (number/day) instead of the 16%precision obtained from the current program (Table Ill). Areduction of 25% in the current sampling efforts, when reallocated, produces a precision of 11% of the annual mean.

Threespine Stickleback. This species was impinged in theJanuary-July period (Table I) and was almost absent fromthe collections during the remaining half of both 1974 and1975. From August through December, the average dailynumber of fish impinged did not exceed 2 fish/day; for thisinsignificant impingement rate, 13 or 14 sampling daysmonthly were expended. The annual mean number ofthreespine stickleback impinged during 1974-1975 was estimated to be 170 ± 89 fish/day, a precision that is within 53%of the estimated mean (Table IV). If the sampling days (164days) are reallocated, a 2% precision would be obtained, anincrease in accuracy of 50%. Similarly, a reallocation of 123samples would produce a precision of ±5% of the annual mean(Table IV). These very large improvements in precision withuse of the optimum allocation procedure result from theseasonality of threespine stickleback impingement.

July August September October November December

1974 1975 1974 1975 1974 1975 1974 1975 1974 1975 1974 1975

67446 5385 132613 442 29561 276 10426 241 13164 2143 28284 3552

186 185 142 208 277 110 127 40 187 86 1770 341

1039 79 0 1 2 0 4 0 0 6 25 11

5 13 3 56 1223 5 105 4 20 115 146 36

8 3 7 21 1 6 0 3 1 6 3 3

140 39 37 234 43 106 14 12 7 24 39 19

43 61 49 35 34 3 14 12 7 21 48 38

1 0 1 0 1 1 0 1 6 4 16 0

384 166 64 165 190 42 180 126 132 1415 743 873

69252 5931 132916 1162 31332 549 10870 439 13524 3820 31074 4873


Table II. Comparison of the Current Program, Optimum Allocation, and Reduced Reallocated Sample Size of Alewife(Alosa pseudoharengus) Impinged (Number/Day) in 1974 and 1975

optimum allocation

pooled current program oplimum allocation (25 % reduction In efforts)

month variance sample size mean ± 2SE sample size a mean ± 2SE sample size a mean ± 2 SE

Jan 54434 13 137 ± 98 4 137 ± 218 4 137 ± 218

Feb 10 870 12 38 ± 46 4 38 ± 97 4 38 ± 97

March 93147 13 216 ± 128 4 216 ± 285 4 216 ± 285

April 92446 178 16 8710 ± 3296 30 8710 ± 0.0 28 8710 ± 961

May 2357299702 18 25576 ± 14832 31 25576 ± 0.0 31 25576 ± 0.0

June 5 123587 13 3787 ± 948 14 3787 ± 881 7 3878 ± 1501

July 4498 057 13 2697 ± 896 14 2697 ± 872 6 2697 ± 1559

Aug 51093570 14 4752 ± 2834 31 4752 ± 0.0 22 4752 ± 1641

Sept 3575257 13 1 148 ± 792 12 1 148 ± 846 5 1 148 ± 1541

Oct 48 083 13 395 ± 93 4 395 ± 205 4 395 ± 205

Nov 949 118 13 612 ± 408 6 612 ± 711 4 612 ± 711

Dec 2572739 13 1 179 ± 678 10 1 179 ± 837 4 1 179 ± 837

annual 164 164 123sample size

mean ± 2SE" 4104 ± 1317 4104±150 4104 ± 279

precision 32% 4% 7%

8 Minimum number of samples allocated is four. b Estimated from Equation 2; see text.

Table III. Comparison of the Current Program, Optimum Allocation, and Reduced Reallocated Sample Size of RainbowSmelt (Osmerus mordax) Impinged in 1974 and 1975

optimum allocationpooled current program oplimum allocation (25 % reduction In efforts)

month variance sample size mean ± 2SE sample size a mean ± 2$E sample size a mean ± 2SE

Jan 90 330 13 292 ± 127 21 292 ± 74 9 292 ± 169Feb 65312 12 261±113 20 261 ± 64 7 261 ± 168March 123852 13 391 ± 149 31 391 ± 0.0 18 391 ± 108Aprii 651247 16 931 ± 277 30 931 ± 0.0 30 931 ± 0.0May 433716 18 477 ± 201 31 477 ± 0.0 31 477 ± 0.0June 2843 13 64 ± 22 4 64 ± 50 4 64 ± 50July 1365 13 14 ± 16 4 14 ± 34 4 14 ± 34Aug 1311 14 13 ± 14 4 13 ± 34 4 13 ± 34Sept 1193 13 15 ± 14 4 15 ± 32 4 15 ± 32Oct 22 13 6±2 4 6 ± 4 4 6±4Nov 144 13 11 ± 5 4 11 ± 11 4 11 ± 11Dec 6162 13 78 ± 33 7 78 ± 52 4 78 ± 55


mean ± 2SE" 213 ± 34 213 ± 11 213 ± 23

precision 16% 5% 11%

a Minimum number of samples allocated is four. b Estimated from Equation 2; see text.

Other Fish. Stratification coupled with optimum allocationwas equally applied to the rest of the representative importantspecies (1), namely smallmouth bass, white perch, spottailshiner, yellow perch, and the seven species of salmonidstreated together as a group. The annual number of fish impinged based on the current program, the reallocated samplesizes, and the 95% precision of the estimates are listed in TableV. The use of the optimum allocation method for samplingdesign shows that a 25% reduction in sampling effort, coupledwith use of the allocation procedure, leads to improvementin the precision of the annual impingement estimates for allspecies discussed.

Total Fish. For the purpose of illustrating the cost and


precision effectiveness of the optimum allocation procedurewhen applied to all species combined, the 1975 data wereconsidered as an example. In this case, the species identity wasignored and all fish were treated as numbers.

The precision obtained in 1975 was 15.8% (Table VI). At areduction level of 25 and 30% of the 1975 sampling efforts, thereallocated samples resulted in a precision of 4 and 5%, respectively, a significant improvement at a reduced cost.

Discussion

One objective of impingement sampling is to determine thenumber of fish impinged annually. A year is too long to besampled as a whole since rate of impingement is seasonal.

Table IV. Comparison of the Current Program, Optimum Allocation, and Reduced Reallocated Sample Size ofThreespine Stickleback (Gasterosteus aculeatus) Impinged in 1974 and 1975

opllmum allocationpooled current program optimum allocation (25% reduction In efforts)

month variance sample slz. mean ± 2SE ·sample size II mean ± 2SE sample size II mean ± 2SE

Jan 2197 13 18 ± 20 7 18 ± 31 4 18 ± 44Feb 51684 12 108 ± 101 29 108 ± 0.0 20 108 ± 57March 509066 13 389 ± 256 31 389 ± 0.0 31 389 ± 0.0April 9217 513 16 1371 ± 1041 30 1371 ± 0.0 30 1371 ± 0.0May 5791 18 81 ± 23 23 81 ± 16 7 81 ± 50June 748 13 30 ± 11 5 30 ± 22 4 30 ± 26July 9002 13 41 ± 40 19 41 ± 27 7 41 ± 63Aug 0.04 14 0.04 ± 0.08 4 0.04 ± 0.19 4 0.04 ± 0.19Sept 0.07 13 0.08 ± 0.11 4 0.08 ± 0.25 4 0.08 ± 0.25Oct 0.2 13 0.15 ± 0.19 4 0.15 ± 0.42 4 0.15 ± 0.42Nov 0.69 13 0.24 ± 0.35 4 0.24 ± 0.77 4 0.24 ± 0.77Dec 4.73 13 1.33 ± 0.92 4 1.33 ± 2 4 1.33 ± 2


mean ± 2SE b 170 ± 89 170 ± 4 170±9precision 53% 2% 5%

II Minimum number of samples allocated is four. b Estimated from Equation 2; see text.

Table V. Comparison of the Annual Mean Number of Fish Impinged (Number/Day) a

smallmouth bass white perch spotlall shiner yellow perch salmonlds d

month N, N2 N3 N, N2 N3 N, N2 N3 N, N2 N3 N, N2 N3

Jan 13 11 8 13 5 4 13 4 4 13 24 16 13 18 11Feb 12 29 23 12 25 7 12 9 6 12 29 29 12 22 14March 13 11 8 13 31 29 13 12 8 13 21 14 13 23 15April 16 10 8 16 30 26 16 24 15 16 24 16 16 22 14May 18 22 16 18 5 4 18 31 22 18 6 4 18 10 7June 13 28 21 13 4 4 13 11 7 13 4 4 13 4 4July 13 8 5 13 4 4 13 7 4 13 11 8 13 5 4Aug 14 23 17 14 6 4 14 31 31 14 15 10 14 5 4Sept 13 6 4 13 30 29 13 22 14 13 4 4 13 4 4Oct 13 4 4 13 8 4 13 4 4 13 4 4 13 4 4Nov 13 7 5 13 10 4 13 5 4 13 6 4 13 16 11Dec 13 5 4 13 6 4 13 4 4 13 15 10 13 31 31

annual 164 164 123 164 164 123 164 164 123 164 164 123 164 164 123sample size

precision at 95% level. C 25 16 23 41 17 27 13 19 22 12 17 43 27 34%

8 Based on number of samples taken in the currenl program (N I ), number of samples allocated (N2), b and number of samples reallocated after a 25 % reductionin the current efforts (N3)b of selected fish species from Lake Ontario. b Minimum number of samples allocated is four. C Estimated from Equation 2; see text.d Represented by seven species combined, see text.

Some degree of stratification is appropriate to increase theprecision of the annual estimate. Each species has a uniqueand different cycle. Estimates of the total (or mean) numberof fish impinged in each stratum are then derived to give theestimate for the whole (or mean) population.

After a sample size is assigned to each stratum, samplingdates are chosen at random. The optimum allocation technique (Equation 1) assumes that the population being sampled is a finite population and that samples are independentof each other. In Tables II-Va minimum of four samples werearbitrarily assigned to each month for which the allocatedsample was less than 4. To collect one sample a week, a morecomplicated technique can be used which is not discussed inthis paper.

The analyses presented above provide an insight into theproblems of sampling biological communities. Because of

diversity and the biological rhythm in the aquatic communities, the homogeneous distribution of sampling effortsthroughout the year must be investigated on a species byspecies basis. Some species are abundant at certain times ofthe year in the near-shore zone where they become most vulnerable to impingement and therefore should be sampledaccordingly. Sampling programs should be most intensive attimes when species enter the study areas and should be minimized during the rest of the year. By so doing. additionalinformation is gained without a cost increase. In fact, thiscould be done for any species at less cost than that of thepresent sampling program.

A sampling program designed to sample the most abundantspecies in spring, for instance, is likely to yield sufficientsamples of other species at peak levels at these times. Forexample. the reallocated sampling programs for alewife (Table


Table VI. Comparison of 1975 Program and Reduced Reallocated Sample Size at 25 and 30%Reduction in Sampling Efforts a

optimum allocationno. 01 samples 25% reducl. 30% reduct.

month SOb laken In 1975 In efforts In eflOfts

Jan 261 14 3 3Feb 686 12 8 7March 1153 13 15 13April 14200 17 30 30May 5216 13 26 25June 962 13 12 11July 695 13 9 8Aug 185 13 2 2Sept 20 13 1 1Oct 22 14 1 1Nov 574 12 8 6Dec 458 14 8 5

annual sample 161 121 112size

precision 15.8 4 5(at 95% level), C %

a All species combined. b Standard deviation. C Estimated from Equation 2; see text.

II) and rainbow smelt (Table III) were sufficient to samplethreespine sticklehack, yellow perch, smallmouth bass, andspottail shiner. On the other hand, salmonids, even thoughfew in number, must be sampled between November andMarch.

The data presented here were collected uniformly over the24-month period and were considered to be a coherent andconcurrent data base tbat represented accurately the variancein the impinged fish community. Transformations (6) werenot performed because the purpose of the optimum allocationwas to assign a sample size based on the variance within astratum and not some transformed variance.

Bias may arise from poor analytical methods, from methodsof measurement or counting, and from the method by whichthe samples were obtained (5). The calculations provided hereincluded all regularly scheduled sampling days plus an additional 19 days in 1974 and 4 days in 1975. These additionaldata collected during periods of high impingement are nonrandom and hence they tend to produce underestimates of theprecision achieved by any sampling design.

The current practice of sampling biological communitiesat equal time intervals is challenged hy our findings. A sampling program is needed for each species separately, especiallythose specIes that are abundant and/or significant in theirtrophic level relationships. Uniform distribution of samplingover, for example, 1 year will result in inadequate samplingof species when they are most abundant. Oversampling whenspecies are scarce or absent adds no substantial information.The use of optimum allocation in sampling design must necessarily replace uniform sampling since "the aim of good


sampling is not so much to obtain a given level of precision(small variance) but to do so with the least cost" (5). Moreprecision for any species can be obtained by stratified sampling with a 25% reduction in the number of days sampled anda corresponding decrease in cost. It should be noted that amore sophisticated sampling scheme and analyses could leadto more precise estimates but the benefit would need to beweighed against the cost.

Acknowledgments

I am very grateful to Messrs. S. Weiss, T, Pease, and Dr. R.Wyman for reviewing the manuscript.

Literature Cited

(l) U.S. Environmental Protection Agency, "Guidance for Deter·mining Best Technology Availahle for the Location, Design, Construction, and Capacity of Cooling Water Intake Structures forMinimizing Adverse Envirollmentallmpact", Section 316~b, P.L.92-500, 1976.

(2) Lawler, Matusky and Skelly Engineers, "The 1974 Nine MilePoint Aquatic Ecology Studies", LMS, Tappan, N.Y., 1975.

(:l) Steel, R G., Torrie, J. M., "Principles and Procedures of Statistics", McGraw-Hili, New York, N.Y., 1960.

(4) Cochran, W. G., "Sampling Techniques", 2nd ed., Wiley, NewYork, N.Y., 1963.

(5) Gulland, J. A., "Manual of Sampling and Statistical Methods forFisheries Biology", FAO, United Nations, Rome, Italy, 1966.

(6) Rohlf, F. ,J., Sokal, R R, "Biometry: Principles and Practice ofStatistics in Biological Research", W. H. Freeman, San Francisco,Calif.,1969.

Received for review February 15, /978. Accepted October 6, /978.

Reaction of Sulfur Oxides with Alumina and Platinum/Alumina

Jack C. Summers

Physical Chemistry Department, General Motors Research Laboratories, Warren, Mich. 48090

• At high temperatures (>500 °C) very little S02 is adsorbedon AbO" in the absence of O2and noble metals. However, inthe presence of O2 significant quantities of S02, above thatoccurring independently in the gas phase, are oxidized to SO"and subsequently stored on the AI20". Platinum greatly enhances the rate of S02 storage on AI20'I' In the absence of O2,Pt appears to catalyze the disproportionation of S02. WithO2 present in the feedstream, Pt catalyzes the oxidation ofS02. S02 and SO" adsorb on different AhO'1 sites. The adsorption of SO'I does not affect the rate of S02 adsorption.These findings are not surprising since S02 is a Lewis base andSO" is a Lewis acid. The surface coverage of AI20" by sulfurranged from a few tenths to a few percent of a monolayer depending on the reaction conditions employed.

Gasoline contains small quantities of organosulfur compounds, e.g., thiophene. These compounds are oxidized to S02in the automobile engine. If the automobile is equipped witha catalytic converter, some of the S02 may be converted toSO". The SO'I readily reacts with water vapor in the exhaustto form H2S04, small quantities of which may then be emittedfrom the converter as an aerosol (1,2).

With the discovery that catalyst-equipped vehicles emittraces of H2S04, considerable effort was expended in characterizing the sulfur emission products (3) and in determiningunder what operating conditions they were formed (4-6). Itwas soon realized that the formation and emission of H2S04

from catalyst-equipped vehicles were complicated by thestorage of sulfur species on the catalyst support. The aluminasupport moderates the quantity of H2S04 that is emitted,since large quantities of H2S04 can be stored when the vehicleis running under oxidizing conditions and released as eitherS02 or H2S under certain reducing conditions (7).

In spite of the intensive efforts to understand the mechanisms of S02 oxidation and storage on noble metal catalysts,much still remains obscure. For example, the role of the baresupport in SOz storage has not been fully elucidated, nor hasthe effect of noble metals on S02 storage in the absence of O2.In this study we try to answer these questions by studying thereactions of S02 and SOZ/02 mixtures over a bare Al20'l support and Pt/AhO:l.

Experimental

The experiments described in this report were conductedin a reactor system constructed so that the inlet and effluentgas streams did not come into contact with metal: the gas lineswere all made of polypropylene tubing up to the SOz analyzer,and the reactor was made of quartz.

The flow rates of the component gases were controlled byrotameters and differential flow controllers. The gases weremixed in a gas blending manifold and then passed into thereactor. In those experimenl~ in which water was added to thefeed, a variable speed metering pump was used to control thewater injection rate. The water was pumped through a capillary tube into the reactor, and dripped onto preheated siliconcarbide (SiC) pellets (20 cm'l). The silicon carbide was placedon top of the catalyst sample. It served to vaporize tbe waterand to mix the water vapor with the S02-containing feedgas.

Any HzS04 (SO,]) made during the course of an experiment

00I3-936XI79/0913-0321$OI.00/0 © 1979 American Chemical Society

was condensed in a Goksoyr-Ross coil (8) which was placedafter the reactor. This was done not for the purpose of sulfateanalysis but to protect the analytical train from corrosiveH2S04. The Goksoyr-Ross coil consisted of a helical condensing coil at the end of which was placed a medium pore(10-15ILm) glass frit filter. The condensing coil and the glassfrit filter were enclosed in a water jacket which was maintainedat 68°C, a temperature which is below the dew point of sulfuric acid. Hence, the sulfuric acid condenses in the coil, whilethe other gases pass through.

The S02 content of the inlet and the effluent gases weremeasured by a pulsed fluorescence analyzer. The inlet SOzlevel was monitored periodically while the effluent SOzlevelswere measured continuously. The O2levels were measured bya paramagnetic oxygen analyzer.

Ahead of the analytical train was a permeation dryer thatwas used to remove the water from the effluent stream.

For the SOz adsorption experiments the inlet gas was passedthrough 10 cm" of either AlzO" or a Pt catalyst supported onthe same type of AbOa. The properties of these materials arelisted in Table I.

The reaction time for the experiments was 300 min. The gashourly space velocity was ~32 000 h- I (STP). The temperature was measured and controlled by a thermocouple placedat approximately the center of the catalyst bed.

A prepurified Nz (99.998% Nz) and a 1.07 vol % S02/N2blend were used in the experiments. The SOz blend containedless than 30 ppm (vol) of Oz. The sulfur pickup on the AI20"and on the Pt/AbO" catalyst was measured at the conclusionof each experiment.

The sulfur stored on the catalysts was measured by a combustion method. The samples were heated in O2to convert thestored sulfur to SOz, which was subsequently measured by aLECO Model 32 IR analyzer.

Two SO,] saturation experiments were run in which theAl20'l and the Pt/AhO" were presaturated with SO" prior toadsorbing SOz.

The presaturation by SO" was accomplished by first passinga feed stream containing 200 ppm (vol) of SOz and 5.1 vol %O2at 400°C and a space velocity of~1O 000 h- 1 (STP) overa 1.0 wt %Pt/AbO,] catalyst (20 cm") to convert the S02 to S03(4). The 1.0 wt % Pt/AI20 3 catalyst was separated from theAlzOa and Pt/AI20,] samples (15 cm") by SiC (30 cm3).

After 750 min, the S02 was turned off and the S03 presaturated samples were heated to 630°C for 120 min in orderto desorb any SOz that might have been adsorbed on thesupport during the exposure to SO:]. S02 is desorbed fromAI20:J at 600°C, but SO" is not desorbed at temperatures lessthan 800°C (10).

The effect of O2on the nature of the stored sulfur specieswas studied by passing either a S02/N2 or a S02/air mixture(1:1 volume) over 75 cm'] of Alz0 3 and 0.1 wt% Pt/AI20,] at 500°c. Nitrogen was first passed (1 h) over the materials prior toexposure to the S02 in order to remove adsorbed water andoxygen. The S02 mixture was then passed over the AI20" orthe Pt/AI20,] for 1 h. Finally, the sample was cooled to roomtemperature in flowing nitrogen. The reactor system consistedof two quartz tubes connected in series and heated by tubefurnaces. The first tube served as a preheater (to 500°C) andthe second contained the catalyst.

Some samples were analyzed by ESCA in order to identifythe oxidation staters) of the adsorbed sulfur species. An


°o!-----,!60,----,-12:-:0:---'~80::----::-':,----:':::,-R.,.tt:lIOl"l Tm"" IrnlOul~S.

018

0'4

"i!cE~o 10

;;•M~•g 006~

~v;

Figure 1. Effect of temperature on the adsorption of S02 on AI20 3 in 00'

the absence of O2

T"mp"r,IIUlC r'cl

Figure 2. Effect of temperature on S02 accumulation on A120 3. Theasterisk indicates atoms of sulfur/cm2BET area

Table I. Catalyst PropertiesAI203 pt/AI203

BET surface area, m2/g 96 91

total pore volume, cm3/g 0.595

wt % Pt 0.055

PI distribution, I'm· edge - 62 ± 30

PI dispersion, % b 73.8

wt % Fe 0.05

wt % Na 0.085

wt % Ca 0.012

• Determined by the SnCl, method (9). b Determined by CO chemisorption.

'4

'0

E8CA-3 instrument was employed for all the measurements.Because the intensity of the sulfur peaks was small, it wasnecessary to do signal averaging.

The sulfur 2P peak was used to identify the chemical shiftof the sulfur species. 8ulfur was present as either 84+ (802or8032-) or 86+ (803or 80.2-). The 84+ species were identifiedby a low-energy shoulder (P1/2 state) on the 86+ band (P3/2

state). The average binding energy of the 84+ species was 167.4eV and the average binding energy of the 86+ species was 169.0eV.


S02 Adsorption on Ah03. Hammerle and Truex (5) reported that in automobile exhaust oxidation catalysis, 803 isprimarily responsible for sulfur storage. However, other investigators have found that significant quantities of 802canalso be stored on Ab03 (l0, 11). As a first step toward understanding the role of the support in sulfur storage, westudied the adsorption of 802on the bare A120 3·

The study of 802 adsorption on AI20 3 was performed bypassing a feedstream containing about 22 ppm (vol) of 802and varying quantities of O2 (0.0-5.1 vol %) in N2 over theA120 3. The rate of 802 removal from the inlet stream wasmeasured as a function of reaction time. 802 removal can

occur by either the adsorption of 802on the Ab03, or by theoxidation of 802 and 803. Characteristically, the initial adsorption of802was rapid followed by a more gradual uptake(5,6).

Temperature was the first variable studied. The rate of 802adsorption and the quantity of sulfur stored on the AI20 3arestrong functions of temperature (4, 5, 10): both decreasemarkedly with increasing temperature (Figures 1 and 2). The


O!-O---:':60,----,-':-:'0,-----"80-:-----,-1-.0----3001--rI"". II,,,, I,m,- In'''luh-sl

Figure 3. Effect of O2level on the adsorption of S02 on AI20 3 at 540°c

decline in 802uptake with increasing temperature is probablyassociated with an increase in the rate of desorption with increasing temperature.

Chang (10) has shown by IR that 802adsorbs on Al20 3inthe absence of O2 to give two distinct species. The first ischemisorbed 802. In vacuo this species is almost completelydesorbed from Ab03 at temperatures as low as 200°C. Thesecond is a surface sulfite (80:12-) species that is chemicallystable up to about 600 °C. 8ince all of our experiments weredone at temperatures of 200°C or above, it is presumably thesurface sulfite species that constitutes the bulk of sulfur storedon the AI20:1• E8CA analysis of AI20:l exposed to 802revealedthe presence of 84+ species. When heated in vacuo at 500°C,the 84+ species can be desorbed from the Ab03.

The surface coverage by sulfur decreased from 2.9 X 1013

to 0.20 X 1013 atoms of sulfur/cm2BET area as the temperature was increased from 200 to 560°C. This coverage represents from 2.9 to 0.2% of a monolayer coverage assuming analumina site density of 1 X 1015 sites/cm2 BET area (12).

The effect of O2 level on 802 adsorption was investigatedat 540°C. One-tenth volume percent O2 had little effect oneither the rate of 802 uptake or the quantity of sulfur storedon the AJ20 a (Figures 3 and 4). Hammerle and Truex (5) reported a similar finding. However, while Hammerle and Truexfound no enhancement in sulfur storage at O2 levels less than

0.50 ,.Inlel502

o fresh

• 503 PrclrCdteu

'4

(4.3 It 1013,.

• AI203

•~M

~ 145.1013)'

~ 0.20

¥~

i 040

!

19.8 .. 1013,"

Pt/AllOJ

a010

o ':-0__.L-_~__!-_--L__..I-_-J O..-:':---'----''---'---'--'--'---'---'--'-_'---'---L.---'_'---Jo 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320

Reacllon Time lrrnnulesl

Figure 4. Effect of 0, level on suit...- storage on AI,03 and PtIAI,03 (5400G). The asterisk indicates atoms of sulfur/em' BET area

Figure 6. Adsorption of SO, on fresh and S03 pretreated AI,03 at 540°c

60

70

Lewis Base Lewis Acid

Figure 5. Molecular structures of SO, and S03 60

1 vol %, we found that the level of sulfur stored was nearly alinear function of the inlet O2 level from 0.1 to 5.1 vol % O2(Figure 4). Since the support used in this study contains ironimpurities (see Table I) and since iron oxides are known tocatalyze the oxidation of S02 (J3), it may be that the iron isresponsible for the increased adsorption of sulfur oxides in thepresence of O2.

ESCA analysis of Al20 3 exposed to a S02102 mixture revealed only the presence of S6+ species which could not bedesorbed upon heating to 500°C in vacuo. Presumably theS02 was converted to S6+ over the iron impurities containedin the AI20 a.

It is desirable to calculate the extent of conversion of S02to SOa during the course of the reaction. Such a calculationcan be done if two assumptions are made: (a) The differencein the rate of S02 removal from the feed when O2is not presentand when O2is present is due to S02 oxidation to S03' (b) S02and S03 adsorb on the Al20 3 independently of each other.

The second assumption is based on the difference in thechemical nature of the sulfur oxides (Figure 5). S02 is a Lewisbase with a lone pair of electrons available to bond with aLewis acid site (I2). S03, on the other hand, is a Lewis acidwith an empty p orbital available for bonding with a Lewisbase site. Thus, the electron structure of the adsorbing sulfuroxide should have a major influence on the nature of its adsorption site.

To test the validity of the second assumption, the Al203 andthe Pt/Al20 a catalyst were presaturated with S03 and thenexposed to a feedstream containing 22 ppm (vol) of S02 in N2.The S02 uptake curves and quantities of sulfur adsorbed (asS02) on the Al20 3and Pt/Al20 3catalyst were virtually identical with those obtained for the fresh materials (Figure 6).Thus, the S02 adsorption sites (both for chemisorbed S02 andS032-) were not affected by adsorbed S03. and the assumption that S02 and S03 adsorb independently on the Al20 3 isverified.

Having established the validity of this key assumption, wecan now calculate the conversion of S02 to S03 at a given 02

•;;840

'"oN

g

3 4

Inlet 02 COnlent(vol. %1

Figure 7. EIIect of O2 level on SO, conversion (300 min) at 540°C

level from the following equation:

% SO to SO = ([S02] - [S02]O,) X 100%2 conv. 3 [S02]inlet

where (S02Jiniet is the inlet S02 concentration, [S021 is the S02in the effluent with no O2 in the feed, and [S02]o, is the S02in the effluent at a given O2 level.

The conversion of S02 to S03 at t = 300 min was calculatedfor each O2level studied (Figure 7). As can be seen from Figure7, this conversion can be significant over bare Al20 3 at higherO2 levels. For example, at 5.1 vol % O2, 14.5% of the S02 isconverted to S03.

At 540°C and with 5.1 vol % O2 in the feed the relativequantities of adsorbed S02 and SOa can be calculated sincewe know that these oxides adsorb independently of one another and adsorb on different sites. The ratio of adsorbed S03


• __--t'r-----t'r----£> 540°C

120Reacll0n Time (minutes)

60o '

2' Inlet 502 2. Inlet S02

AI203 • • ,/ . • • •20 200°C

PlIAI 2 0 3 350°C

Figure 8. S02 removal over AI20s and PlIAlsOs in the absence of O2al54.0 DC

Figure 10. Effect of temperature on S02 removal by Pl/AI20s at 5.1 %O2 and 540 DC

~Igure 9. Effect of O2level on the adsorption of S02 on PlIAI20s at 540DC

~OS02 under these conditions as calculated from the data inFigure 4 is approximately 10.

SO:! Adsorption on PtfA120 3. The adsorption of 802onPt/Ah03 was studied at 540°C in the absence of O2. ThegeQeral characteristics of this adsorption experiment weresiIllil~r to those observed for AhOs (Figure 3). However, ther!!;te of 802 disappearance over Pt/AI20 s was significantlygr.eater than that observed for the AI20 s (Figure 8). This observat,ion is consistent with the finding that larger quantitiesof sulfur were stored on Pt/AhOs than were stored on the bare<\120 s (Figure 4): in the absence of O2, Pt/AhOs stores approximately 10 times as much sulfur as the bare AI20s after300 m.in of reaction.

E8CA reveals the presence of both 84+ and 86+ species fora Pt/AhOs catalyst exposed to 802. Like the AI20 s samplethat was exposed to 802, the 84+ species can be removed uponheating at 500 DC in vacuo.

It is apparent that Pt catalyzes 802adsorption. Chang hasstudied the adsorption of 802on AhOs and Pt/AhOs by infrared spectroscopy (I4). He has observed that at 400 DC inthe absence of O2, 802adsorbs on Pt/AhOs but not AI20 s toform surface sulfate species. He has postulated that Pt cata1yzes the disproportionation of 802to yield the surface sulfate~pecies. In a separate experiment, it was shown that Pd alsocatalyzes the rate of adsorption on 802.

The significance of this finding is obvious: by studying just802uptake on the corresponding bare AhOs support, one failsto get a real measure of how much sulfur may be adsorbed onPt/AhOs at elevated temperatures in the absence of O2.

Effect of O2 on S02 Storage on PtfAhOs. Next, the effects of O2level on 802 removal and sulfur storage were investigated. In accord with the kinetics of S02 oxidation (15),802removal is a sensitive function of the O2level. At 540°Cthe rate of 802removal (Figure 9), the rate of 802oxidation(Figure 7), and the quantity of sulfur stored on the catalyst(Figure 4) increase markedly with increasing O2content.

Finally, the effect of temperature on the reaction of802and5.1 vol % O2was studied (Figure 10). At 200 DC, the 802uptake curve over Pt/AI20 3was identical with that obtained forbare AhOs. This indicates that at 200 DC Pt catalyzes neitherthe oxidation nor the disproportionation of 802. At 350 DC twoopposing processes occur that affect 802removal (Figure 10):thermal desorption of 802and 802oxidation. From 200 and350 DC there is a decrease in the quantity of 802adsorbed onthe bare AI20 3 support. The rate of oxidation, however, increases from 200 to 350°C (3). The net result of these processes on sulfur storage after 300 min of reaction is that therate of 802removal at 350 °C is slightly greater than at 200DC (Figure 10). At 540°C, the oxidation of 802clearly dominates and this results in a rate of 802 removal that is muchgreater than that observed at 350 DC.

Effect of H20 on S02 Removal. Because automotive exhaust contains appreciable quantities of H20 (~10 to 13 vol%) and because, up to this point, our experiments were performed with dry feedstreams, a few experiments were doneto determine the effect of water on the sulfur oxide removalreactions. In all the experiments the results were the same:water slightly inhibits sulfur storage. The uptake curves asillustrated in Figure 11 are typical ofthose obtained in thepresence and absence of H20.

Prior to running the 802adsorption and oxidation experiments, it was determined that H20 (10 vol %) had no effecton the gas-phase oxidation of 802at 540 DC and with 5.1 vol% O2in the feedstream.

The removal of 802 from the feedstream by AhO:l andPt/Ah03 was studied at two O2 levels (0 and 5.1 vol %) andwith each of these at two H20 levels (0 and 10% vol). Underall conditions studied, H20 inhibited sulfur storage as wasshown by a decrease in the rate of S02 removal from thefeedstream on both the Al20 3 (16) and the Pt/AI20 s. Theabsolute differences of sulfur stored on the Al20 s and Pt/Al20 3were independent of the reaction conditions.

Conclusions

This study has supported previous work that has found that80s is the primary sulfur species stored on oxidation emissioncontrol catalysts. However, we have shown that the mechanisms of storage are more complicated than previously

••_~_---...., DO'\. 02

_-6-----.!:I1 0'1;, 02

--Sl 5 1°" 02

'.0

•

120RCittl,on T"m' (ll1InultlSI

In\t:t 502

I

60

••20

2'

~ 16D

IrC; 6

'"


A,',ll hOIl 1"11" l"unul"sl

Figure 11. Effect of H20 on S02 by Pt/AI20 3 at 5.1% O2 and 540°c

Literature Cited

Received for review May 17, 1978. Accepted October 6,1978. Thispaper was presented at the 176th National Meeting of the AmericanChemical Society (Division of Colloid and Surface Chemistry),Miami Beach, Fla., Sept 10-15, 1978.

(1) Pierson, W. R., Hammerle, R. H., Kummer, J. T., pre8ented toSociety of Automotive Engineers, Detroit, Mich., Feb 1974, PaperNo. 740287.

(2) Beltzer, M., Campion, R. J., Peterson, W. L., presented to Societyof Automotive Engineers, Detroit, Mich., Feb 1974, Paper No.740286.

(3) Mikkor, M., Hammerle, R. H., Truex, T. J., Ind. Eng. Chern. Prod.Res. Dev., 16,217 (977).

(4) Taylor, K C., Ind. Eng. Chern. Prod. Res. Dev., 15,264 (1976).(5) Hammerle, R. H., Truex, T. J., presented at the Division of Pe

troleum Chemistry, 172nd National Meeting of the AmericanChemical Society, San Francisco, Calif., Aug 1976, PETR-034.

(6) Hammerle, R. H., Mikkor, M., presented to Society ofAutomotiveEngineers, Detroit, Mich., Feb 1975, Paper 750097.

(7) Barnes, G. J., Summers, J. C., presented to Society of AutomotiveEngineers, Detroit, Mich., Feb 1975, Paper 750093.

(8) Goksoyr, H., Ross, K,J. Inst. Fuel, 35,177 (962).(9) Michalko, E., U.S. Patents 3 259 454 and 3 259 589.(0) Chang, C. C., J. Catal., 53,374 (1978).(11) Deo, A. V., Dalla Lana, I. G., Habgood, H. W.,J. Catal., 21,270

(1971).(12) Peri, J. 8., J. Phys. Chern., 69,211 (965).(13) Chun, K C., Quon, J. E., Environ. Sci. Technol., 7, 532

(1973).(14) Chang, C. C., Infrared Studies of S02 on Pt-Alumina, General

Motors Corp., Warren, Mich., 1978, private communications.(15) Olson, R. W., Schuler, R. W., Smith, J. M., Chern. Eng. Prog.,

46,614 (1950).(Ili) Glass, R. W., Ross, R. A., Can. J. Chern., 50,2537 (1972).

••••

_.n-------D----O l~o H20

':::-...-__----c,.-----<r-----V No H20

60 120

thought. Impurities in the AI20 3 support can catalyze S02oxidation, and Pt and Pd apparently can catalyze the disproportionation of S02 to form surface sulfate species.

S02 and S03 adsorb on different AI20 3sites, and they adsorb independently of each other. Consequently, it was possible to determine the relative quantities of sulfur stored onA120 3 as S02 and as S03.

Acknowledgments

The experiments were conducted by J. Ulicny and D.Fournier.

2'

• •20

j 16

D

~S 12

~~

8

Chloroform and Chlorophenol Production by Decarboxylation of Natural Acidsduring Aqueous Chlorination

Richard A. Larson" and Arlene L. Rockwell

Stroud Water Research Center of the Academy of Natural Sciences of Philadelphia, R.D. 1, Box 512, Avondale, Pa. 19311

• Naturally occurring carboxylic acids of several structuraltypes reacted in dilute solution with aqueous hypochlorite toafford decarboxylation products. Incorporation of chlorineinto the residual organic molecule occurred. Citric acid wasefficiently converted to chloroform at pH 7 by a pathwayprobably involving 3-ketoglutaric acid as an intermediate; inacidic or alkaline solution, yields of CHCb were lower. Severalother enolizable keto acids (including <ill three isomers ofresorcylic acid) were likewise precursors of CHCl3 or of substances which could thermally be converted to CHCI3; yieldsvaried widely. Two substituted benzoic acids common tonatural waters, p-hydroxybenzoic acid and vanillic acid, weredecarboxylated by hypochlorite with the production of chlorophenols.

Although the association of chlorophenols with unpleasantodors and tastes in drinking waters was recognized many yearsago, fundamental studies on the kinetics and mechanisms ofaqueous chlorination reactions have been sparse until recentyears. It has now become evident that treatment of drinkingand wastewaters with chlorine leads to the formation of avariety of organochlorine compounds. Chloroform (CHCb),other haloforms, chlorinated phenols and phenolic acids, andchlorinated quinones, benzoic acids, and heterocyclic com-

pounds are only a few of the many structural types which havebeen identified (1-4). Much of the organically bound chlorinehas not been fully characterized; a large fraction is associatedwith macromolecular organics (5).

Chlorine dissolved in water ("aqueous chlorine") existsprincipally as hypochlorous acid (HOC\) between pH 3.4 and7.5, and as the hypochlorite anion OCI- at higher pH values.The reactions of aqueous chlorine with organic molecules fallinto three categories, addition, substitution, and oxidation.Chlorohydrins are produced by the addition of HOCI to olefinic double bonds, and chlorine can also be incorporated bysubstitution reactions into activated aromatic nuclei, amines,and enolizable ketones. Many oxidative reactions of hypochlorite are known, but until recently they have been neglected in discussions of water chlorination since it has beenassumed that chlorine was not incorporated into organicmolecules during their oxidation.

There are a few references to oxidative decarboxylation inchlorination reactions in aqueous solution. The presence ofchlorophenols (4, 6) and chlorinated quinones (7) in pulpbleaching liquors has been demonstrated. These compoundsare largely produced through oxidative cleavage of lignin sidechains (4-substituted guaiacols and catechols) by aqueouschlorine in strongly acid solution. Among the model compounds studied was p-hydroxybenzoic acid, which under theseconditions was rapidly converted to 2,4,6-trichlorophenol

0013·936XI79/0913-0325$01.00/0 © 1979 American Chemical Society Volume 13. Number 3. March 1979 325

.6(11). 4-Chloro-2-methoxyphenol was synthesized from S02Clzand guaiacol (12).

Chloroform Production from Pure Acids. The organicacid, dissolved in 50 mL of 0.05 M phosphate buffer, wastreated at ambient temperature with a tenfold molar excessof hypochlorite solution. At intervals, a 10-mL portion wasremoved and extracted with 5 mL of petroleum ether. Fromthe organic layer, 1.0 ILL was injected onto a Chromosorb-101GC column (stainless steel, 2.4 m X 3 mm i.d.) held isothermallyat 165 ·C. Argon-methane (95:5, 30 mL/min) was usedas a carrier gas. Chloroform, which emerged at 5.8 min, wasdetected using a 63Ni electron capture detector; its identitYwas confirmed by mass spectroscopy. Peak height was measured and compared to standards. A blank, not containing anorganic acid, was always run. In a few experiments, theaqueous reaction mixture was injected directly, without petroleum ether extraction, to measure "potential" CHCl3(13).

Chloroform Production from Microbial Cell Contents.Basal medium (10 g of NaOAc, 3 g of [NH4!zS04, 3 g ofKHzP04, 250 mg of CaClz, 250 mg of MgS04, 10 mg of inositol,2.2 Ilg of biotin, 1 mg of calcium pantothenate, 1 mg of pyridoxine-HCI,l mg of thiamin-HCl, 1 L of distilled water) wasinoculated with 0.2 mL of turbid suspension of fine surfacesediment obtained from White Clay Creek, Chester County,Pa. The mixture was shaken aerobically at 28 ·C for 3 days.Microscopic observation of the culture revealed several microbial forms, principally coccoid bacteria and filamentousfungi. An aliquot of the culture was removed and filteredthrough a tared glass fiber ultrafilter; the filter was dried andweighed to determine total microbial biomass. The remainderof the culture was centrifuged; the pellet was washed threetimes in pH 7 phosphate buffer (to remove medium) anddisrupted ultrasonically in this buffer. The suspension wascentrifuged and filtered (0.45-llm membrane filter); the filtrate was passed over a column of anion exchange resin (BioRad AG-1-X2, formate form, 1 X 6 cm). The column waseluted with two volumes of 0.1 M HCOOH ("weak acid"fraction) and then two volumes of 16 M HCOOH ("strongacid" fraction). These conditions have been shown to separatedicarboxylic from tricarboxylic acids (14). The two fractionswere divided into two equal portions and evaporated at roomtemperature. One portion was esterified for determination ofcarboxylic acids by GC (15), and the other was redissolved in5.0 mL of pH 7 phosphate buffer. A small portion of this solution was reserved for total organic carbon determination(Dohrmann DC-54), and the remainder was chlorinated byadding 50-100 ILL of Clorox and allowed to stand overnight.Finally, a 2.0-mL portion of the reaction mixture was extracted with 2.0 mL of petroleum ether for chloroform determination.

Production of Chlorophenols and Chlorinated Aromatic Acids. Methods for chlorination and analysis of aromatic acids were described previously (16). In brief, anaqueous solution of the sodium salt of tile acid (5 X 10-4 M)was treated with equimolar NaOCI at 20-25 ·C. Products wereextracted from the acidified reaction mixture with EtOAc andanalyzed by GC.

In kinetic experiments, the acid (1.5 X 10-0 M) was treatedwith 5X excess NaOCI in 0.2 M phosphate buffer at 8 ac. Thereaction was quencbed by addition of excess Na2Sz03 to analiquot portion; its UV spectrum was determined after adjustment of pH to 12 ± 0.5. From the intensities of the peaksat 280 and 244 nm (Figure 1), the concentrations of acids(including both chlorinated and unchlorinated species) andchlorophenols were determined.

Hypochlorite concentrations were determined by the FACTSmethod (17).

Mass spectra of chlorinated aromatic acids and chioro-

(1)

(2)

HXHCI2

VOH

pH 8.5 ..5000 ppm

OCI G>

pHI A18000 ppm >CIYCI

CI2 OH

..

200 250 300 350

6'"OH

6"OH

replaced during aqueous chlorination under unspecified"large-scale" conditions, with the formation of chlorinatedstyrene derivatives (Reaction 3) (10). The conditions used in

(Reaction 1) (8). Amino acids have been oxidatively decar-

.~

boxylated to carbonyl compounds; in one instance, a-methylDOPA was converted to a ketone by reaction with NaOCI(Reaction 2) (9). The carboxyl group of p-coumaric acid was

.5

.3

..

these reactions are not typical of those encountered in watertreatment, and it was of interest to determine whether similarreactions might proceed under milder conditions. We reportthat several common natural carboxylic acids are readily attacked by hypochlorite in dilute solution, with loss of CO2andthe incorporation of chlorine into the residual molecule.

Experimental

Materials. Most organic acids and phenols were obtainedcommercially and recrystallized. Hypochlorite solution wasClorox hypochlorite bleach, nominally 5.25% NaOCI (verifiediodometrically). Buffered solutions were made up in deionized,chljrcoal-filtered water using sodium phosphate salts. Petroleum ether was Fisher pesticide grade material, checkedfor electron-capturing contaminants before use. 5-ChINovanillic and p-dimethylaminohenzoic acids were synthesizedby silver oxide oxidation from the corresponding aldehydes

Wavelength (om)

Figure 1. Absorption spectra of p-hydroxybenzoic acid (solid line) andp-chlorophenol (dashed line) at pH 12.0. Concentration, 1 X 10-5 M.Other chlorophenols and chlorinated derivatives of p-hydroxybenzoicacid had virtually identical absorption maxima, but absorbances varied


Table I. Chloroform Production from NaturallyOccurring Carboxylic Acids

yieldacid concn. M pH tlme,h CHCI3, %

2;4-dihydroxybenzoic 7.5 X 10-4 9.6 0.33 92 s

2,6-<lihydroxybenzoic 7.5 X 10-4 8.0 0.75 90 s

3,5-<lihydroxybenzoic 7.5 X 10-4 7.8 0.75 78 s

3-ketoglutaric 7.5 X 10-4 8.1 0.75 94.4 s

citric 1.0 X 10-4 7.0 2 4.4 s

2.0 X 10-4 7.0 2 8.9 s

7.5 X 10-4 7.0 2 77.9 a

7.5 X 10-4 5.5 2 21.2 s

7.5 X 10-4 9.3 2 <1 s

isocitric 7.5 X 10-4 8.0 0.75 <1 s

fumaric 5.0 X 10-4 8.0 18 23 b

maleic 5.0 X 10-4 8.0 4 14b

7.5 X 10-4 8.0 22 <1 s

malic 5.0 X 10-4 8.0 24 30 b

7.5 X 10-4 8.0 120 1.1 s

oxaloacetic 7.5 X 10-4 8.0 20 1.7 S

salicylic 7.5 X 10-4 8.0 20 2.1 s

a By extraction with petroleum ether. b By direct aqueous injection.

phenols were determined by Shrader Laboratories (Detroit,Mich.).


Chloroform Production. Experiments on the productionof CHC1:J from several naturally occurring carboxylic acids aresummarized in Table I. All three carboxylic acids related toresorcinol (2,4-dihydroxybenzoic acid, 2,6-dihydroxybenzoicacid, and 3,5-dihydroxybenzoic acid) gave good yields ofCHCI3. Resorcinol itself and several simple substituted derivatives have already been shown to be efficient precursorsof CHCl3 (18); the active site for chlorination is the carbonatom flanked by phenolic hydroxyl groups. In this context, itis interesting that 2,6-dihydroxybenzoic acid, in which thiscarbon atom bears a carboxyl substituent, is approximatelyas good a precursor of CHCh as are the other two isomers, orresorcinol itself. The conversion of this compound to CHChprobably involves decarboxylation. Both phenolic hydroxylsare required for CHCla production, as shown by the result forsalicylic acid (2-hydroxybenzoic acid).

Several other naturally occurring acids having {j-keto groupsor which could be converted to {j-keto acids by simple reactions with hypochlorite were tested for CHCl3 production. Itwas anticipated that the methylene group between the carbonyl and carboxyl groups would rapidly be enolized andreadily attacked by hypochlorite. Subsequent decarboxylationwould afford a dichloromethyl or trichloromethyl ketonewhich could readily be converted to chloroform by unambiguous.processes.

3-Ketoglutaric acid (acetonedicarboxylic acid) reactedrapidly with hypochlorite at near-neutral pH, giving virtuallyquantitative yields of CHCla within a few minutes. The highreactivity of 3-ketoglutaric acid may be explained by increasedenol stability conferred by the two carboxylate groups available for hydrogen bonding:

~.-~" -00 -- a --0 0

O~OIn nature, 3-ketoglutaric acid is produced by enzymatic

oxidative decarboxylation of citric acid (19). We showed thatthe reaction probahly also occurs in hypochlorite solutions;citric acid gave high yields of CHCla when chlorinated in

Table II. Production of CHCI3 from UltrasonicallyDisrupted Microorganisms (Total Biomass Production,2.7 g)

citric CHCI3fraction lotaIC./-Lg acid, ,Ltg produced, ,Ltg

strong acid 7760 313 20weak acid 2170 N.D.s N.D.

8 N.D.• none detectable.

near-neutral solutions (78% at pH 7). The reduced yieldsnoted in acidic or alkaline media may be explained by a ratedetermining oxidative decarboxylation (Reaction 4) requiring

(\ C000'/Iy CI ~ C000

HO ~O)1~0 ------'> O{ (4)

000C O~ COoe

the presence of the citrate trianion (pK a = 6.40) and hypochlorous acid (pKa = 7.49). The optimum pH for this reactionwould be that at which the concentrations of these two speciesare maximal, namely (6.40 + 7.49)/2, or 6.94. Isocitric acid,which would not afford a highly stabilized enol on decarboxylation, produced little or no CHCl3 when chlorinated. Simple{j-keto or {j-hydroxy acids (oxaloacetic, malic) were also notgood precursors of CHCI3. Fumaric and maleic acids, havingOI,{j unsaturation (which could give chlorinated {j-keto acidsby addition of HOCI to their double bonds and oxidation),afforded compounds which could be converted to CHCh byheating (direct aqueous injection), but little or no free (petroleum ether extractable) CHCla.

Citric acid occurs in tap water, in natural waters, and ineffluents; levels as high as 10.2 mglL (5.3 X 10-5 M) have beenreported (20-22). Although exudates of stems and roots ofhigher plants contain citric acid (23), the principal source inwaters is probably the metabolic activity of the aquatic microflora. To determine whether cellular contents or exudatesof aquatic microorganisms could produce CHCla when chlorinated, we grew a mixed population of microorganisms isolated from a surface sediment in a defined medium containingacetate as the sole carbon source. The harvested cells weresonically disrupted, and the supernatant was partitioned byion exchange chromatography into a strongly acid fraction(containing citric acid and other polycarboxylic acids) and aless acidic fraction. The two fractions were chlorinated separately; CHCla was produced only from the strongly acidfraction (Table Il). Citric acid was presumably the source ofmuch of the CHCla. The yield of CHCh, based on citric acid,was 10%.

The 3-ketoglutaric and citric acid results may also be relevant to the formation of CHCh from natural dissolved organicpolymers ("humic acids", "fulvic acids"). Enzymatic degradation of lignin and related polyphenols, probable precursorsof these materials, affords ring-opened products containing{j-keto acid groups (24). These structures may persist in humicsubstances; a polycarboxylic acid, similar in some respects tohomopolymerized maleic anhydride, has been identified asa major constituent of soil fulvic acid (25).

Chlorophenol Production. In order to react rapidly withhypochlorite, an electrophilic reagent, aromatic compoundsrequire activation by electron-donating substituents (26).Because the carboxyl group withdraws electrons, simple aromatic carboxylic acids would not be expected to react byaddition of hypochlorite to the ring; thus, benzoic acid 0,Table III) did not react appreciably with hypochlorite underour conditions. However, incorporation of a phenolic hydroxylgroup allowed attack of hypochlorite; salicylic acid (2) andp-hydroxybenzoic acid (4) readily formed chlorinated additionproducts. 5-Chlorosalicylic acid was the principal product


Table III. Reactions of Substituted Benzoic Acids with Aqueous Hypochlorite a

COOH

62

5""" 134

substituent addition decarboxylationno. product (8) b % product(s) C

1 H H H H 0 02 OH H H H 1 14 03 H OH H H 0 04 H H OH H 2 22 35 H H OCH3 H 1 71 1d

6 H H NH2 H 2 82 07 H H N(CHa12 H 1 96 1d

8 H OCHa OH H 1 8 29 H OH OH H 1 9 0

10 H CI OH H 1 <1 211 H CI OH CI 0 112 H N02 OH H 0 113 H OCHa OH OCHa 1 16 0

%

78

<1

4

92

9779

36

a Yields derived from GC peak areas, relative to total area of all peaks observed (including any residual starting material). b Number of products retaining thecarboxyl group detected by GC. C Number of products shown by GC-MS to have lost the carboxyl group. d Structure not established by GC-MS; peak had shorterGC retention time than starting material.

2,4,6-trichlorophenol was produced from 3,5-dichloro-4hydroxybenzoic acid (II).

A free phenolic hydroxyl group appeared to be required forefficient decarboxylation (cf. 5), but incorporation of an additional methoxyl group into p-hydroxybenzoic acid (vanillicacid, 8) still allowed chlorophenol production to occur. Theproducts were 4-chloro-2-methoxyphenol and a dichloro-2methoxyphenol. Kinetic studies at lower reactant concentrations, however, showed that the decarboxylation of vanillicacid was much slower than that of p-hydroxybenzoic acid.

If two phenolic hydroxyl groups were present (9), chlorophenols were not detected. A phenolic acid with a nitro substituent (12) afforded only a decarboxylation product; noaddition product retaining the carboxyl group was detected.Apparently, decarboxylation of a phenolic acid is sensitive tothe nature of further ring substitution. Resonance stabilization of the phenolate anion generated by decarboxylation ofa cyclohexadienone would be favored hy electron-withdrawingsubstituents at the ring positions ortho to the phenolic hydroxyl.

At reactant concentrations and conditions more nearlytypical of those encountered in the environment (pH 6.7, 8DC), 10-5 M (1.5 ppm) p-hydroxybenzoic acid consumed 3equiv (1.5 ppm) of hypochlorite in 15 min. Products of thereaction were assessed by UV spectroscopy. About 55% of thestarting material was converted to chlorophenols; another 30%retained the carboxyl group. The rate of decarboxylation wasmaximal at pH 7.9 and was very slow below pH 6. Additioncompounds retaining the carboxyl group were still producedat lower pHs, however.

Substituted benzoic acids are common in the environment;p-hydroxyhenzoic acid has been identified in numerousstudies of soils (28-30) and waters (31-33). It is probable thatsome of the chlorophenols of drinking and wastewaters areproducts of the chlorination of these aromatic acids, particularly at periods of high concentrations of natural dissolvedorganic matter (spring thaw, autumn leaf fall) (34).

Acknowledgment

We thank S. W. Friant for valuable discussion and experimental assistance.

COOH

~0CIYCI

OH

!HOCI-co

2

CI

~OCI::::::"" Cl

j"~,~_H--'O'-C_I .._OC'I

CI

QOH~~~

I~~~126

OH OH OH

Figure 2. Summary of aqueous chlorination reactions of p-hydroxybenzoic acid

from 2, whereas 4 gave a mixture of the 3-chloro and 3,5-dichloro acids 10 and II. m-Hydroxybenzoic acid (3), however,could be recovered practically unchanged from aqueous hypochlorite solutions, even when the reaction temperature wasincreased to 90°C.

In addition to phenolic acids, benzoic acids containing alkoxyl, amino, or alkylamino substituents were sufficientlyactivated for addition reactions with hypochlorite (5-9, 13).

A few phenolic acids also underwent efficient decarboxylation reactions with hypochlorite. A mixture of 4-chlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol was produced when p-hydroxybenzoic acid (4) was chlorinated. Because no phenol, 2-chlorophenol, or 2,6-dichlorophenol wasdetected among the products, it is unlikely that decarboxylation occurred without chlorination of the 4 position. Theproducts of this reaction may be accounted for by a multistepscheme summarized in Figure 2. Decarboxylation probablyoccurs through 2,5-cydohexadienone intermediates bearingCI and COOH on the same carbon atom; similar stable compounds were identified in the chlorination of other parasubstituted phenols (27). The chlorophenols were shown byTLC to be present in the reaction mixture, and were accordingly not artifacts of the workup or derivatization procedures.

Chlorinated phenolic acids were likewise readily decarboxylated; 3-chloro-4-hydroxybenzoic acid (10) gave a mixtureof 2,4-dichlorophenol and 2,4,6-trichlorophenol, whereas only


Literature Cited

(I) Rook, J. J., Water Treatment Exam., 23,234 (1974).(2) Jolley, R. 1.., J. Water Poilu!. Control Fed., 47,601 (1975).(3) Glaze, W. H., Henderson, ,J. E., IV, J. Water Pollut. Contra/. Fed.,

47, 241l (1975).(4) Lindstrom, K., Nordin, J., J. Chromatogr., 128,13 (1976).(5) Rook,.J. J., J. Am. Water Works Assoc., 68, 168 (1976).(6) Dence, C., Sarkanen, 1<., Tappi, 43,87 (1960).(7) Das, B. S., Reid, S. G., Betts, J. I.., Patrick, 1<., J. Fish. Res. Roard

Can., 26,3055 (1969).(8) Sarkanen, I<. V., Dence, C. W., J. Orli. Chem., 25,715 (1960).(9) Slates, H. L., Taub, D., Kuo, C. H., Wendler, N. L., J. Orli. Chem.,

29,1424 (1964).(10) Shimizu, Y., Hsu, R. Y., ('hem. Pharm. Rull., 23,2179 (1975).(Il) Pearl, /. A., J. ()rg. Chem., 12, 8f> (1947).(12) Sohma, T., Konishi, K., Takeda Kenkyu.,ho Nempo, 26, 138

(1967); Chem. Abstr., 68, 95447s (1968),(13) Nicholson, A. A., Meresz, 0., Lemyk; B., Anal. Chem., 49,814

(1977).(14) Aue, W. A., Hastings, C. R., Berhardt, K. 0., Pierce,J. 0., II, Hill,

H. H., Moseman, R. F., J. (,hromatoli'., 72,259 (1972).(I f» Larson, R. A., Weston, J. C., Howell, S. M., J. Chromatogr., Ill,

4:3 (1975).(16) Rockwell, A. I.., Larson, R. A., in "Water Chlorination: Envi

ronmental Impact and Health Effects", Jolley, R. L., Gorchev, H.,Hamilton, D. H., Eds., I> 67, Ann Arbor Science Publishers, AnnArbor, Mich., 1978.

(17) "Standard Methods for the Examination of Water and Wastewater", p 342, American Public Health Association, Washington,D.C., 1976.

(18) Rook, ,J. ./., cnviro/!. Sci. Tee/mol., I I, 478 (1977).(19) Flutterwllrth, J., Walker, T. K., Riochem. J., 23,926 (1929).

(20) Bjork, R. G., Ana/. Biochem., 63,80(1975).(21) Kempf, T., Pribyl, J., Gas- Wasserfach., Wasser-Abwasser, 116,

278 (1975).(22) Afghan, B. K., Leung, R., Ryan, J. F., Water Res., 8, 789

(1974).(23) Tiffin, L. 0., Plant Physio/., 41,510,515 (1966).(24) Christman, R. F., Oglesby, R. T., in "Lignins: Occurrence, For

mation, Structure and Reactions", Sarkanen, K. V., Ludwig, C. H.,Eds., p 769, Wiley-Interscience, New York, N.Y., 1971.

(25) Anderson, H. A., Russell, J. D., Nature (London), 260, 597(1976).

(26) Carlson, R. M., Carlson, R. E., Kopperman, H. I.., Caple, R.,Environ. Sci. Techno/., 9,674 (1975).

(27) Smith, J. G., Lee, S.-F., Netzer, A., Water Res., 10, 985(1976).

(28) Whitehead, D. C., Nature (London), 202,417 (1964).(29) Wang, T. S. C., Yang, T.-K., Chuang, T. T., Soil Sci., 103,239

(1967).(30) Lodhi, M. A. K., Am. J. Rot., 63, 1 (1976).(31) Hunter, J. V., in "Organic Compounds in Aquatic Environ

ments", Faust, S. D., Hunter, J. V., Eds., p 51, Marcel Dekker, NewYork, N.Y., 1971.

(32) Degens, E. T., Reuter, J. H., Shaw, K. N. F., Geochim. Cosmochim. Acta, 28,45 (1964).

(3:1) Matsumoto, G., Ishiwatari, R., Hanya, T., Water Res., 11,693(1977).

(34) Larson, R. A., Freshwater Bioi., 8,91 (1978).

Received for review August 7, 1978. Accepted October 6,1978. Presented in part at the Conference on Water Chlorination (Environmental Impact and Health Effects), Gatlinburg, Tenn., Nov 1977.Supported by the Environmental Associates, Academy of NaturalSciences of Philadelphia.

Determination of Several Industrial Aromatic Amines in Fish

Gregory W. Diachenko

Division of Chemical Technology, Food and Drug Administration, Washington, D.C. 20204

• A procedure is described for tbe determination of selectedindustrial aromatic amines in fish. Ground fish tissue is di~ested with aqueous sodium hydroxide and extracted withbenzene. The extract is washed with dilute acid and cleanedup usin~ gel permeation chromatography. The amines areseparated and quantitated using nitrogen-selective gao;-liquidchromatography. Recoveries of N -ethyl-N -phenyl benzylamine, N -ethyl-N-(m-tolyl)benzylamine, N,N -dibenzylmethylamine, diphenylamine, and N-phenyl-\-naphthylamine from fish tissue fortified at levels of 20-100 ppb (JIg/kg)averaged at least 80%. Recoveries of I-naphthylamine and3,3'-dichlorobenzidine were somewhat lower. Fish samplesobtained from rivers near nine textile and dyestuff manufacturers known to use certain aromatic amines have beenanalyzed. 1-Naphthylamine was detected in fish from theBuffalo and Delaware Rivers downstream from two dyestuffmanufacturers. N -Ethyt-N -phenylbenzylamine and Nethyl-N -(m-tolyl)benzylamine were also detected in theBuffalo River fish.

The carcinogenicity of several industrial aromatic amineshas stimulated interest in investigatin~ possible environmental contamination by this class of compounds. In 1974, theOccupational Safety and Health Administration issued regulations on \4 chemical compounds that were either knownor suspected human carcino~ens (I), including aromaticamines such as 1- and 2-naphthylamine and :l,:l'-dichlorobenzidine. These carcinogenic compounds could create a potentially serious problem should there be widespread con-

tamination of the human food chain.The Food and Drug Administration became concerned with

the possible contamination of human foods by industrial aromatic amines because of their known or suspected carcinogenicity, relatively large production volumes, and potentialfor biomagnification. Quantities produced vary from approximately 584 X \()6 Ib/year for aniline to several millionpoundsfyear for numerous other compounds (2). Many aromatic amines are used as intermediates for dyes and pigments,and as antioxidants and antiozonants in rubber products.These varied applications suggest many possible modes ofentry into the environment, ran~ingfrom direct discharge toconversion of azo dyes to the precursor amines by bacteria_

Many workers have published detection schemes for variousaromatic amines, using gas-liquid, high performance liquid,or thin-layer chromatography, sometimes coupled with ancillary techniques such as ultraviolet or fluorescence spectrometry (3-/2). Most investigations into amines in fish orfoods have centered around naturally derived volatile aminessuch as di- and trimethylamine, or more recently the N -nitrosamines (13-/6). To this author's knowledge, however,there are no published methodologies or findings of unhalogenated industrial aromatic amines in aquatic organisms suchas fish.

This study reports the presence of microgramfkilogram(parts per billion) quantities of selected industrial aromaticamines in fish tissue and an analytical technique for theirdetection and quantitation. The technique is aimed at detectin~ the less water-soluble aromatic amines which are expected to biomagnify or concentrate to higher levels in fishtissue than are found in the aqueous environment. The pres-

This article not subject to U.S. Copyright. Published 1979 American Chemical Society Volume 13, Number 3, March 1979 329

Table I. Retention Time of Industrial Aromatic AminesRelative to Parathion a

a Data were obtained using a 6 ft X 2 mm i.d. 10% OV-101 column at 200°C with 20 mLlmln carrier flow using Hall detector, nitrogen mode. Retentiontime of parathion is about 8 min.

ence of I-naphthylamine, N -ethyl-N-phenylbenzylamine, andN-ethyl-N-(m-tolyl)benzylamine in fish collected near dyemanufacturing plants is reported.

Experimental

Reagents. Burdick and Jackson "Distilled in Glass" solvents were used for all extractions. Inorganic reagents wereACS or analytical grade. Aromatic amine reference materialswere obtained from Aldrich Chemical Co. (Milwaukee, Wis.);purity was usually greater from 95%.

Caution: Benzene is presently considered to be a carcinogen. Use adequate ventilation.

Procedures: Sample Preparation and Storage. Fish neardye or textile manufacturing plants were collected by variousstate agencies either by netting or electroshock techniques,and immediately placed on ice or dry ice. Frozen fish werefilleted, doubly ground, and thoroughly mixed. Fish werestored frozen if immediate analysis was not possible.

Digestion and Extraction. Prepared fish tissue (50 g) wasdigested in a I·L beaker containing 200 mL of 1 N NaOH for2 h on a steam bath with occasional stirring. The cooled digestwas transferred to a l-L separatory funnel containing 15 mLof saturated NaCI solution. One hundred milliliters of benzenewas added and the funnel shaken for 30 s. Four hundredmilliliters of distilled water was then added and the mixtureshaken for an additional 60 s. After allowing the layers toseparate, the water layer was drained into a 1-L beaker andthe benzene layer was transferred to a 500-mL separatoryfunnel and reserved. The extraction of the aqueous layer wasrepeated in the original separatory funnel with a second100-mL portion of benzene, with vigorous shaking for 90 s.After allowing the layers to separate, the aqueous layer wasdiscarded and the benzene extracts were combined in the5OO-mL separatory funnel.

Acid Wash. One hundred fifty milliliters of 2 X 10-4 MH2S04was added to the combined benzene extracts and themixture shaken for 60 s. After allowing the emulsion to partially separate, the separatory funnel was placed in a clean l-Lbeaker and stored in a freezer until both layers were frozen(usually overnight). Centrifugation may also be used to break

compound

N,N-<lielhyl-m-loluidine3,4-<lichloroaniline1-naphlhylamine2-naphlhylaminediphenylamine1-elhyl-1-naphlhylamineN,N-<libenzylmelhylamineN-phenylbenzylamineN-elhyl-N-phenylbenzylamineN-elhyl-N-(m-tolyl)benzylamineN-nilrosodiphenylamine2-nitrodiphenylamine1-nilro-2-naphlhylaminebenzidineN-phenyl-1-naphlhylamineN,N'-bis(dimelhylpenlyl)-p-phenylenediamineN-phenyldibenzylamine3,3'-<lichlorobenzidine

rei retention time

0.130.200.260.280.330.360.420.430.490.660.880.950.951.4

1.62.52.64.1

the emulsion. After the layers were allowed to thaw, theaqueous layer was discarded; the clear benzene extract waspassed through a drying column containing about 40 g of anhydrous Na2S04 and collected in a 5OO-mL Kuderna-Danishconcentrator equipped with a 10-mL collector. The driedbenzene extract was concentrated on a steam bath to about10 mL, using a 3-ball Snyder column (Kontes Glass Co.).

Gel Permeation Chromatographic (GPC) Cleanup. Thebenzene extract was diluted to 12.0 mL and 10.0 mL was injected (via loop) onto a GPC column. The GPC apparatus wasa DuPont 820 liquid chromatograph (or any system capableof pressurizing the column) equipped with a 2.5 in. o.d. X 19in. stainless steel column containing 270 g of Bio-Beads S-X2(Bio-Rad Laboratories, Richmond, Calif.) and a Model COO6sample introduction valve with a lO-mL sample loop (WatersAssociates, Framingham, Mass.). Methylene chloride(CH2CI2) mobile phase at a flow rate of 8 mL/min was usedto elute the sample. The first 500 mL of CH2Ch eluate (containing the bulk of the lipid) was discarded and the next 440mL (containing the aromatic amines) collected in a 5OO-mLKuderna-Danish concentrator with a 10-mL graduated collector. The solution was then concentrated on a steam bathto less than 10 mL in the Kuderna-Danish concentratorequipped with a 3-ball Snyder column. Petroleum ether (150mL) was added and reconcentrated to less than 10 mL to remove the bulk of the CH2CI2. The extract was further concentrated to 0.5 mL or less, using a gentle stream of nitrogenat room temperature.

Gas Chromatographic (GC) Separation and Quantitation. The cleaned up fish extracts were analyzed on aHewlett-Packard Model 5710 gas chromatograph equippedwith a temperature programmer and nitrogen-phosphorusdetector Model 18789A or Model 310 Hall electrolytic conductivity detector in the catalytic reductive nitrogen mode.The nitrogen-phosphorus detector operating conditions were:250°C; 14 V; 3 mL/min hydrogen; 60 mUmin air; 30 mL/minnitrogen carrier gas; 6 ng of 1-naphthylamine gave 50% fullscale deflection (FSD) at 1 X 4 attenuation and a retentiontime of 2.7 min, using the 10% OV-101 column describedbelow.

The Hall detector operating conditions were: 1/4 in. quartzcombustion tube with nickel catalyst operated at 900°C; 50%NaOH on 80/100 mesh Chromosorb W (HP) scrubber; 60 ssolvent vent; 40-60 mL/min hydrogen carrier gas; 0.4 mL/minwater conductivity solvent; 10 ng of 1-naphthylamine gave50% FSD at 2 X 1 attenuation and a retention time of 3.4 min,using the 10% OV-101 column described below.

Three different 6 ft X 2 mm i.d. coiled glass columns wereused for GC analyses. They were packed with 10% OV-101, 6%OV-17, and 5% OV-225, respectively, each on 80/100 meshChromosorb W (HP). The injection port temperature was 250°C for all columns. Temperature programming conditions forthe 10% OV-101 and 6% OV-17 columns were: initial 160 or180°C for 8 min, program to 220 °C at 4 °C/min, hold at 220°C for 16 min. The 5% OV-225 column was operated at 150°Cfor 8 min, programmed to 180 °C at 4 °C/min, and held at 180°C for 16 min. The carrier gas was adjusted to give a retentiontime of 3-4.5 min for )-naphthylamine (about 20-40 mL/min).

A 5-30-ILL sample aliquot (equivalent to about 400-2500mg offish) was injected onto the 10% OV-101 GC column witha 20-mL/min carrier flow and 200°C isothermal columntemperature to det.ermine retention times relative to parathion. Table I lists the values for several industrial aromaticamines.

Identification and quantitation can be accomplished on anyof the three GC columns. Quantitation is accomplished bycomparing sample peak heights to those of standards.Bracketing of sample injections with standards is desirable


Table II. Recovery of Aromatic Amines from Spiked a Ocean Perch Tissue

compound

l-naphthylaminediphenylamineN-ethyl-N-phenylbenzylamineN-ethyl-N-(m-tolyl)benzyiamineN.N-dibenzylmethylamineN-phenyl-l-naphthylamine3,3'-dichlorobenzidine

recovery, %

16, 26, 30, 32, 34, 35, 3998,98, 102, 102, 104, 105, 10785, 85, 86, 92, 9588,97,98,98, 10278,79,80,81,86,86,9180,80,86,88,97,98,9950,54,54,60,61,64,75,80,88

av.recovery, %

301028997839065

av devfrom mean

5.42.64.03.24.07.1

11.9

sIddev

7.53.44.65.24,88.4

13.0

• Spiking levels ranged from 20 to 100 ppb (edible portion basis).

due to occasional sensitivity variations of 10-30% over thecourse of the day. The identity of aromatic amines in fish wasconfirmed by retention times on all three GC columns, andalso by comparison of major sample fragments with those ofstandards by GC-mass spectrometry (MS). A Finnigan 1015C quadrupole mass spectrometer coupled to a Varian 1700 gaschromatograph through an all-glass jet separator was used forGC-MS identification.

Acid Partitioning Cleanup for GC-MS Identification.In some samples excessive background necessitated additionalcleanup to allow positive GC-MS identification of aromaticamines. Additional cleanup was performed by diluting thesample extract to 10 mL with petroleum ether in a 60-mLseparatory funnel and extracting the amines twice with 25-mLportions of 0.2 M H2S04. The aqueous extract was made basicby the addition of 3.0 g of NaOH, and extracted twice with50-mL portions of benzene in a 125-mL separatory funnel.The combined benzene extracts were passed through anNa2S04 drying column and concentrated to <0.5 mL in aKuderna-Danish concentrator as previously described, priorto GC-MS analysis.


The analysis of fish for aromatic amine residues presentedseveral problems which have been overcome to varying degreesby the described methodology. The Food and Drug Administration's multiresidue pesticide procedures for both nonfattyand fatty foods (17) were tried in unsuccessful attempts torecover various aromatic amines from spiked fish tissue. Poorrecoveries of these compounds were traced to sorption by bothtissue and the Florisil column used in these procedures. Theselosses were avoided by the use of an alkaline digestion andGPC. The GPC system was a modification of that used byStalling (I8) and previously reported by the author (19). Thedilute acid wash removed what we suspect are the more basicamines normally present in fish which interfered with thedetection of several industrial aromatic amines below theO.4-ppm spiking level. The use of the Hall or nitrogen-phosphorus detectors made possible selective detection of nitrogen-containing compounds.

The efficiency of the procedure was tested by adding 20-100ppb (edible pohion basis) of several aromatic amines to oceanpercb tissue and allowing the ethyl acetate solvent to air drybefore carrying out the procedure. Table II gives the averagerecovery and standard deviation for each of the tested aromatic amines. Recoveries do not significantly vary as a function of spiking level in the 20 to 100 ppb range and are therefore grouped for statistical purposes. The data indicate thatfairly reproducible recoveries averaging better than 80% wereobtained for the less polar secondary and tertiary aromaticamines tested. The more basic, water-soluble primary aromatic amines such as I-naphthylamine and :1,3'-dichlorobenzidine gave lower and more variable recoveries. One of thecauses of these lower recoveries was the partitioning of these

H 16 2·' MIN

Figure 1. Nitrogen-selective gas chromatograms. (A) Extract from fishtissue spiked at 80 j.tg/kg with each compound. Hall electrolytic conductivity detector at 1 X 10 attenuation; 200 mg of fish equivalent injected; 10% OV-l0l column. Peaks represent: (1) 1-naphthylamine(4 ng), (2) diphenylamine (16 ng), (3) N-ethyl-1-naphthylamine (11 ng),(4) N,N-dibenzylmethylamine (13 ng), (5) N-ethyl-N-phenylbenzylamine(14 ng), (6) N-ethyl-N-(m-tolyl)benzylamine (16 ng). (7) N-phenyl-1naphthylamine (14 ng), (8) 3,3'-dichlorobenzidine (10 ng). (B) Extractfrom unspiked fish tissue (200 mg of fish equivalent injected; 10%OV-l0l column)

more basic compounds into the 2 X 10-4 M H2S04 during theacid wash step.

The use of nitrogen-selective GC detectors eliminates manypotential chromatographic interferences, but compoundsnaturally present in fish or those that are generated by theprocedure may present a problem at low detection levels.~'igure 1 illustrates a nitrogen-selective gas-liquid chromatogram obtained for one of the fish samples spiked at 80ppb with selected aromatic amines. Several nitrogen-con·taining peaks can be observed in the unspiked ocean perchsample, but none interfered with the detection of the aromaticamines tested in this laboratory. These unidentified peakshave been detected in fish collected from many locations andare apparently naturally derived or procedure-generated.Attempts at GC-MS identification were unsuccessful.Quantitation levels ranged between 1 and 20 ppb dependingon the compound and the levels of other gas chromatographable nitrogen compounds present in the sample.

Fish obtained from near nine dye or textile manufacturinglocations in New York, New Jersey, Micpigan, and Georgiawere analyzed for selected aromatic amines. Diphenylamine,N -phenyl-1-naphthylamine, I-naphthylamine, and 3,3'-dichlorobenzidine were specifically analyzed for, because of theirrelatively large production volumes, carcinogenic potential,


I I I8 16 2~ ~lIN

Figure 3. Nitrogen-selective gas chromatogram of extract from Delaware River minnow composite collected about 100 yards downstreamfrom dyestuff manufacturer. Hall electrolytic conductivity detector at1 X 16 attenuation; 200 mg of fish equivalent injected; 6% QV-17column. Aromatic amine identified in fish: (1) 1-naphthylamine (8 ngequivalent)

'"'F.,. ,.

~ ::c.. ..'" '"

n 8 II, 2·' mNFigure 2. Nitrogen-selective gas chromatogram of extract from BuffaloRiver fish composite collected about 100 yards downstream fromdyestuff manufacturer. Hall electrolytic conductivity detector at 1 X10 attenuation; 730 mg of fish equivalent injected; 10% OV-101 column. Aromatic amines identified in fish: (1) l-naphthylamine (7 ngequivalent), (2) N-ethyl-N-phenylbenzylamine (125 ng equivalent), (3)N-ethyl-N-(m-tolyl)benzylamine (7 ng equivalent)

8 N.D. = none detected. b Concentration uncorrected for incomplete recoveries averaging 30 %.

Table III. Aromatic Amines Identified in Fish SamplesCollected Near Dyestuff Manufacturing Plants

and the possibility of discharge near their manufacturing anduse sites. The fish collected near dye manufacturers on theBuffalo River near Buffalo, N.Y., and on the Delaware Rivernear Deepwater Point, N.J., contained I-naphthylamine.None of the previously named aromatic amines were detected{<1-20 pphl in fish collected from the other seven samplingsites. The fish from the Buffalo River also contained Nethyl-N-phenylhenzylamine and N -ethyl-{m-tolyllbenzylamine. These compounds were identified by matching retention times with standards on the three GC columns, andalso hy detection of the major mass fragments of I-naphthylamine and N -ethyl-N -phenylbenzylamine at the correctretention times by GC-MS.

Levels of the aromatic amines found in the Buffalo andDelaware River fish samples are tabulated in Tahle III. Thevalues listed for I-naphthylamine are not corrected for thevariable recoveries, averaging about 30%, from spiked fishtissue. In the Buffalo River samples the highest concentrationsof the aromatic amines were detected in fish collected nearestthe Buffalo dyestuff manufacturing plant, with decreasing orundetectable amounts in fish collected upstream or severalmiles downstream from the plant, The 1974 Directory of

sit.:. sample

Buffalo River, N.Y.carp fillet composites1 mile upstream100 yards downstream4 miles downstream

Delaware River, N.J.minnow composite(whole fish)

concentration, ppbN~ethyl. R-ethyl-

N-phenyl- N-(m-Iolyl)1-naphthylamlne benzylamlne benzylamlne

N.D." 51 5110" 170 10N.D. 45 5

40" N.D. N.D.

Chemical Producers (20) indicates that I-naphthylamine,N -ethyl-N-phenylbenzylamine, and N -ethyl-{m-tolyl)benzylamine were produced by the dyestuff manufacturer. Thesegeneral concentration trends and production informationindicate that these aromatic amines are probably derived fromthe dye manufacturer.

Figures 2 and 3 illustrate nitrogen selective chromatogramsobtained from the Buffalo and Delaware River fish extracts.The major nitrogen-containing compound that was identifiedis N -ethyl-N-phenylbenzylamine, found in the Buffalo Riverfish. Many unidentified nitrogen-containing compounds werepresent in these and other fish samples obtained from nearthe seven other dye or textile manufacturers. Most of thesecompounds were present at very low levels (estimated to bein the 10-100 ppb range). Generally, there were more nitrogencompounds in fish from these locations than in those fromnonindustrial areas. Some of these unidentified nitrogencompounds have also been detected in fish samples from riverand marine environments distant from industrial dischargers,and are probably naturally occurring or generated by theprocedure. The low concentrations encountered, combinedwith the presence of many other compounds, preventedGC-MS identification of many of the nitrogen-containingcontaminants in the fish samples.

In summary, a procedure has been developed for the determination of selected industrial aromatic amines in fish. Itis quantitative for the less polar secondary and tertiary aromatic amines tested at concentrations in the 20-100 ppbrange. This procedure was used to detect and quantify aromatic amines in fish collected downstream of two dyestuffmanufacturers.

Acknowledgment

The author thanks Virgil Warren, Division of ChemicalTechnology, Food and Drug Administration, Washington,D.C., for the GC-MS confirmation of the aromatic amines infish extracts and John Spagnoli, New York State Departmentof Environmental Conservation, Russel Cookingham, NewJersey State Division of Fish, Game and Shellfish, John Hesse,Michigan Department of Natural Resources, and Jim Nix,Georgia Department of Natural Resources, for providing fishsamples and invaluable assistance.


Literature Cited

(1) Stender, J. H., Fed. Regist., 39,3756 (1974).(2) Preliminary Report on U.S. Production of Selected Synthetic

Organic Chemicals, U.S. International Trade Commission,Washington, D.C., March 16, 1978.

(3) Bowen, B., Anal. Chem., 48,1584-7 (1976).(4) Savitsky, A., Siggle, S., Anal. Chem., 46, 153-5 (1974).(5) Bowman, M. C., King, J. R., Holder, C. L., Int. J. Environ. Anal.

Chem., 4,205-23 (1976).(6) EI-Dib, M. A.,J. Assoc. Off. Anal. Chem., 54, 1383-7 (1971).(7) Yasuda, S. K., J. Chromatogr., 104,283-90 (1975).(8) Ivan, G., Aiutacu, R., J. Chrvmatogr., 88,391-7 (1974).(9) Jakovijevic, I. M., Zynger, J., Bishara, R. H., Anol. Chem., 47,

2045-6 (1975).(10) Holder, C. L., King, J. R., Bowman, M. C., J. Toxicol. Environ.

Health, 2,111-29 (1976).(11) Mieure, J. P., Dietrich, M. W., J. Chromatogr. Sci., 11,559-70

(1973).(12) Masuda, Y., Hoffmann, D., Anal. Chem., 41,650-2 (1969).

(13) Fazio, T., Damico,J. N., Howard, J. W., White, R. H., Watts,J.0., J. Agric. Fvod Chem., 19,250-3 (1971).

(14) Fine, D. H., Rounbehler, D. P., Oettinger, P. E., Anal. Chim.Acta, 78,383-9 (1975).

(15) Fine, D. H., Ross, R., Rounbehler, D. P., Silvergleid, A., Son, L.,J Aliric. Food Chem., 24, 1069-71 (1976).

(16) Singer, G. M., Lijinsky, W., J. Agric. Food Chem., 24, 550-5(1975).

(17) "Pesticide Analytical Manual", Vol. I, Sections 211 and 212,Food and Drug Administration, Washington, D.C., 1973.

(18) Stalling, D. L., Tindle, R. C., Johnson, J. L., J. Assoc. Off. Anal.Chem., 55,28-32 (1972).

(19) Diachenko, G. W., Laboratory Information Bulletin No. 1745,Field Sciences Branch, Food and Drug Administration, Rockville,Md., Dec 11, 1974.

(20) "1974 Directory of Chemical Producers, United States ofAmerica", Stanford Research Institute, Menlo Park, Calif., 1974.

Received for review June 26, /978. Accepted October 7, /978.

Determination of Air-Water Henry's Law Constants for Hydrophobic Pollutants

Donald Mackay', Wan Ying Shiu, and Russell P. Sutherland

Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A4

In these equations N is the mass flux (g.mol m-2 h- I), KI. andKG are the liquid- and gas-phase mass transfer coefficients(m h-1j, KOL is the overall liquid phase mass transfer coefficient (m h- I ), H is the Henry's law constant (atm m:1g·mol-1),

C is the solute concentration in the liquid phase (g·mol m-3),

P is the solute partial pressure in the air (atm), T is the absolute temperature (K), and R is the gas constant (m:1 atmK·mol- 1 K-l). The ratio of the resistances in the gas and liquidphases (rc:t.l can be shown to be:

difference and a mass transfer coefficient which is essentiallya mass conductivity and can be regarded as a diffusivity divided by a diffusion pathlength. Calculating the volatilizationrate requires summation of the two phase resistances (whichare essentially the reciprocals of the conductivity) and oftenone phase resistance dominates. This summation requires aknowledge of H, since it is usually assumed that the soluteconcentrations immediately on either side of the interface arein equilibrium and the magnitude of the concentration drivingforce which can be achieved in each phase thus depends onH.

The relevant equations which have been developed elsewhere are summarized as follows (J):

Liss and Slater (2) have suggested that typical environmental values of KI. and K c; are, respectively, 0.2 m h-1 forO2 transfer and 30 m h-1 for H20 transfer. Thus the ratio(KdKI.) is of the order of 150 and should usually lie in therange of 50 to 300. It is recognized that increasing solute molecular weight decreases KG and KI., probably as a result ofa decrease in diffusivity, but the effect on both coefficients isexpected to be similar in magnitude; thus the ratio may berelatively constant. The distribution of resistances rcl. between the two phases is illustrated in Figure 1 at 25°C as afunction of H for various values of this transfer coefficientratio. If the value of H is greater than 5 X 10-:1atm ma g·mol-1

(which implies a compound of relatively high vapor pressure

• A novel system is described for the determination of Henry's law constants (H) for hydrophobic compounds betweenair and water with an accuracy of about 5%. The method involves measurement of the compound concentration in onlythe water phase while being stripped isothermally from solution at a known gas flow rate. Determinations of H weremade for benzene, toluene, ethylbenzene, chlorobenzene,naphthalene, biphenyl, and phenanthrene, and agreementwith available literature data was satisfactory. Since, if anytwo of the three quantities H, vapor pressure, and aqueoussolubility are known, the third may be calculated, it is suggested that the method may be useful for obtaining accuratesolubility and vapor pressure data or for verifying existingdata. The method may be suitable for elucidating the extentof sorption of volatilizing compounds in aqueous environments and quantifying the role of sorption in reducing volatilization rates.

Volatilization from water bodies to the atmosphere is recognized as a significant environmental pathway for solutessuch as gases and some hydrophobic organic pollutants suchas hydrocarbons and chlorinated hydrocarbons. A knowledgeof the Henry's law constant (H) is essential in calculating thedirection and rate of transfer. If the solute concentrations inthe air and water are determined, it immediately gives thedirection of the transfer, and in cases where the solute is closeto equilibrium an accurate value of H is essential. In mostcases, although the direction of transfer is obvious, the distribution of resistance to mass transfer between the air andwater phases and hence the overall rate depends on H.

The volatilization process is generally accepted as consistingof diffusion of the solute from the bulk of the water to theinterface, followed by transfer across the interface, and finallydiffusion from the interface to the bulk of the air phase.Measurements of concentration profiles show that most of thediffusive resistance lies a few millimeters above and below theinterface and it is believed that the interface itself offers littleor no resistance. The diffusive flux in each phase is conventionally expressed as the product of the solute concentration

N = KodC - PIH)

I/KOI. = I/KL + RT/HKG

rC,1. = RTKLlHKc

(1)

(2)

(3)

0013.936XI79/0913·0333$OI.00/0 © 1979 American Chemical Society Volume 13, Number 3, March 1979 333

H. otm mJ/mol.

Figure 1. Effect of Henry's law constant on ratio of gas to liquid phaseresistances 'GL for three KG/ KL ratios

and/or low solubility), then Equations 1 and 2 reduce toEquation 4 below and the resistance lies almost totally in theliquid phase. If the Henry's law constant is below 5 X 10-0 atmm3 g·mol- 1 (which implies a compound of low vapor pressureand/or high solubility) then the equations reduce to Equation5 below and the resistance lies in the vapor. In the intermediate range the resistance of each phase is significant andcalculation of the overall transfer rate depends on the valueof H and thus an accurate value is essential. When H > 5 X10-3 atm m3 g·mol- 1

The conventional method of obtaining H experimentallyis to measure the concentration of the solute in the liquid andthe vapor at equilibrium possibly over a range of concentrations. This method is accurate if the concentrations are high,but for many pollutants this is impossible because the solutesare only sparingly soluble in water and have low vapor pressures. Thus, concentration measurements become necessaryat very low concentrations. Further, to avoid extrapolationfrom high concentrations it may be desirable to measure Hat the actual environmental concentration which may be verylow, as for example with PCBs in water.

There is also a need to obtain H data at environmentalconcentration levels in the presence of impurities such asmineral matter or dissolved or suspended organics.

H can also be calculated if the solute vapor pressure andaqueous solubility are known, but unfortunately many highermolecular weight compounds such as PCBs or PNAs have verylow vapor pressures at environmental temperatures and eithervapor pressure data are not available or they can only be obtained by extrapolating from high temperatures with someattendant loss in accuracy. If the solute is solid then extrapolation of the vapor pressure through the triple point is necessary. This can be quite inaccurate. The relationship betweenaqueous solubility, vapor pressure, and H provides an additional incentive for measuring H since, if data are availablefor any two, the value of the third can be calculated, thusproviding invaluahle verification of experimental data. Itshould be noted that in calculating H as the ratio of solutevapor pressure and aqueous solubility, it is essential that theseproperties both be of the solute in the same (solid or liquid)

P = YP'l' = .qP' = 18 X 10-6C')'ps = HC

where H = 18 X lO-o"'(P' (m'l atm g·mol- I ).

This latter equation is useful since there are some correlations for"'( as a function of molecular properties (4) which canbe used to estimate H. As was discussed earlier in calculatingH as the ratio of pure component vapor pressure to aqueoussolubility, it is essential that both properties refer to the samestate (liquid or solid).

A mathematical description of the stripping process can bereadily assembled if it is assumed (i) that the system is isothermal, (ii) the liquid phase is well mixed, (iii) tbe vaporbehaves ideally, (iv) Henry's law is obeyed over the relevantconcentration range, (v) t.he volume of liquid remains constant, (vi) tbe partial pressure of tbe solute is small comparedto tbe total pressure, and (vii) tbe solute in the exit vapor isin equilibrium with the liquid. A mass balance for the solutegives tbe transfer rate as:

{v = h = x"'(P' = y</>PT

where"'( is the activit.y coefficient in the liquid phase, </> is thefugacity coefficient in the vapor phase, p, is the vapor pressureof the pure liquid solute (atm), and P'l' is the total systempressure (atm). The activity coefficient is defined on aRaoult's law convention basis, i.e., "'( = 1 when x = 1. Since PTis relatively low, </> can be assumed to be unity for nonassociating solutes. If the solute is a solid at the system temperature,p, is tbe vapor pressure of the hypothetical subcooled liquid.This equation can be rearranged to give a definition of Henry'slaw, and it can be shown that in dilute aqueous systems, H(Henry's law constant) is as given below, where C is theaqueous phase solute concentrat.ion (g.mol m-:1) and P is thesolute partial pressure (atm):

Theoretical

Equilibrium between vapor and liquid can be characterizedby equating the fugacities h and {v, which can be related tothe mole fractions x and y in the liquid and vapor phases:

wbere (; is t.he gas now rat.e (m'l h- I ), V is the volume of the

- V dC/dt = PG/RT = HGC/RT (mol h- I )

state. For example, H can be calculated as the ratio of a solidvapor pressure to a solid solubility. It is erroneous to use a solidsolubility and a liquid vapor pressure extrapolated throughthe triple point to the subcooled liquid region. The interpretation of H becomes more complex for liquid mixtures suchas hydrocarbon oils or PCBs in which the pure substances maybe solid at environmental temperatures, but the mixtures maybe liquids.

The aim of this work is to devise a simple method of determining H for hydrophobic organics at environmentalconcentrations and in natural waters. In principle, the systemconsists of a known volume of water through which a knownvolume of air is sparged under conditions such that the soluteconcentration in the exit gas is essentially in equilibrium withthe aqueous concentration. From a plot of the solute aqueousconcentration vs. time, H can be deduced, and any dependence of H on concentration can be elucidated. In principle,the method is similar to that of Dilling et al. (3), who alsomeasured volatilization rates of a number of organohalidesby following the concentration in solution, but the presentsystem is believed to be an improvement in that it gives datafor the fundamental thermodynamic quantity H. Dilling'smethod measures an evaporation rate which is dependent onH and on the diffusion properties of the system which dependon the ambient turbulence levels in the air and water. In thepresent system, diffusive processes are separated from equilibrium properties.

(.5)

(4)

OwOj1o1!

(!l

10 f2a:

51zwitW

10.

,j,-----------------99

••

N= KdC - P/H)

When H < 5 X 10-0 atm m:1 g.mol- 1

N = KdCH - P)/RT


gas exit

'Mlter jack.et

inlet

~- 'MJ.ter jack.et outlet

O~_~5

em.

10° ,.-----,----,----,----,-----,

T~ 296 K

V. 750 em' ,G-: 292.05 em/min.

Biphenyl

.,10 ';-----,,';,----f;c---,--~-----;~--__;;!

o 20 t 40 min. 60 00 \00

Figure 3. Typical plot of absorbance vs. time for volatilization of biphenyl

Figure 2. Diagram of apparatus

liquid (m3), R is the gas constant (m3 atm g.mol- I K-I), Tisthe system temperature (K), and t is time (h). This equationcan be integrated from initial conditions when t = 0 and C =Co to give:

In (CICo) = -(HG/VRT)t

A plot of log concentration against time should be linear witha slope of -(HGIVRT).

For situations where the partial pressure in the exit vaporis not in equilibrium with the liquid, a mass transfer rate expression can be derived if it is assumed that the liquid is wellmixed, i.e., C is constant vertically, and that the solute partialpressure in the gas rises by dP during exposure to an interfacial area increment dA (m2) giving:

G dP/RT = KOL dA(C - P/H)

Rearranging and integrating between limits of P = 0, A = 0,and P = P, A = A give:

P = HC(1 - exp(-KoLARTIGH))

where K 01. is the overall liquid phase mass transfer coefficient(m h-I) and A is the interfacial area in the column (m2). Highvalues of K OL and A and low values of H favor a close approach to equilibrium (ionditions as the exponential termtends to zero. The magnitude of this term can be determinedby changing the liquid depth, and thus the term A, and observing the dependence of the slope of the log C vs. time curveonA.

Experimental

Figure 2 is a diagram of the apparatus. Nitrogen from ahigh-pressure cylinder was passed through a low-pressure lineregulator, Matheson Model-70, and a Brooks Sho-Rate 150,Model 1355-02B-V rotameter, and then bubbled throughwater to saturate it and prevent water evaporation from the

stripping vessel. The gas was then introduced into the bottomof the stripping vessel through a sintered glass disk. The system was maintained at 25 ± 0.01 °C. The exit gas flow rate wasmeasured by a soap bubble flow meter.

The concentration of dissolved hydrocarbon in the waterwas measured by a Beckman Model DK2A UV spectrophotometer containing a l-cm path length flow cell. A Cole Parmer micropump was used to pump a sample from the strippingcolumn through the flow cell. The volume of the flow cellcircuit was about 5 cm3 and the flow rate about 5 cm3 S-I.

The hydrocarbons used were of the purest quality availableand were used as received without further purification. In allcases, the purity was quoted as greater than 99%. Doubledistilled water was used in all experiments.

The general procedure was to form a concentrated solutionof the hydrocarbon in the water and then strip the hydrocarbon using the gas. The initial hydrocarbon solution was obtained either by equilibrating some hydrocarbon with waterin a separate vessel, then transferring it to the column, or byby-passing the nitrogen stream after saturation with waterthrough a vessel containing the hydrocarbon solution. Thehydrocarbon then evaporated into the nitrogen stream anddesorbed into the water, approaching the equilibrium solubility. Both methods were satisfactory.

The procedure was to measure the water volume in thestripping vessel and set the nitrogen flow rate at 50 to 500 cm3

min-I. Flow rates were measured at 5-min intervals. Thepump was turned on only for sampling and was run at 5 cm3

S-I for about 1 min. The sampling frequency varied from onceevery 2 min to once every 20 min, depending on the rate ofvolatilization. At each sampling, the absorbance of the hydrocarbon and time were recorded. A plot of ahsorbance vs.time was then obtained as illustrated in Figure 3.

In order to determine the extent of approach to equilibrium,the column was operated with various liquid volumes, thesupposition being that as liquid depth decreased and contacttime decreased, the approach to equilibrium would be reduced. The approach to equilibrium was calculated using the


Table I. Experimental Results and Comparison with Literature Values

Henry's law constant (H),m 3 atm g-mol- 1

compel (state)

benzene (liquid)toluene (liquid)ethylbenzene (liquid)chlorobenzene (liquid)naphthalene (solid)biphenyl (solid)acenaphthene (solid)phenanthrene (solid)

aq solubilityat 25 OCt

9 m-3

1780 (5)

515 (5)152 (5)472 (6)31.4(4)

7.0 (4)

3.93 (4)1.29 (4)

vapor pressureal 25 OCt

aIm

0.125 (8)

0.0374 (8)

0.0125 (8)0.0156 (7)1.16 X 10-4 (7)

calcd

5.49 X 10-3

6.66 X 10-3

8.73 X 10-3

3.71 X 10-3

4.68 X 10-4

expU

5.55 X 10-3

6.64 X 10-3

8.43 X 10-3

3.77 X 10-3

4.83 X 10-4

4.08 X 10-4

1.46 X 10-4

3.93 X 10-s

100'~-----------------~

o60

o

20

o 4 6 6 10 12 14 16LIQUID DEPTH, em.

Figure 4. Approach to equilibrium as a function of liquid depth forbenzene volatilization

mass transfer model developed earlier.In some later experiments in which the effect of humic acid

on volatilization rate was studied, analysis of the aqueousnaphthalene solutions was by direct fluoresence using anAminco-Bowman spectrofluorometer. The humic acid wasobtained from Aldrich Chemical Co.

Results

The accuracy of the method is primarily dependent on thedegree of approach to equilibrium, i.e., the extent to which thevapor and liquid at the top of the column are in equilibrium.In order to quantify this, the system was operated at Illiquiddepths ranging from 0.9 to 38.5 cm. The data were then fittedto the mass transfer equation derived earlier and values of theapproach to equilibrium were calculated and plotted againstliquid depth as illustrated in Figure 4.

If it is assumed that the bubbles are of constant size and riseindependently, then as the gas rate G increases, tbe numberof bubbles in the column increases and the interfacial areaincreases, all in proportion. There should not, tberefore, bea significant dependence of approach to equilibrium on theratio A/G, which appears in the exponential term. The datain Figure 4, interpreted as an exponential approach to equilibrium (as is suggested by the mass transfer equation fornonequilibrium situations), indicate that for benzene eachIO-cm depth yields an 80% approach to equilibrium. Thus, tbe38.fi cm used here will give >99% approach to equilibrium. Themass transfer equation indicates that systems of lower H willapproacb equilibrium faster. It is relatively simple to test tbeapproach to equilibrium for any system by determining the

336 Environmentat Science & Technology

10''..-------------------.

~ 10z

go

~

'">~'"a:

SORBANT ADDED

' 0 20 40 60 eo 100 120 140TIME. min

Figure S. Effec! of humic acid sorben! addition (22.3 mg L-') onnaphthalene concentration (as indicated by fluorescence intensity)during volatilization

sensitivity of the experimentally determined H to the liquiddepth.

The system was first tested using benzene, toluene, andethylbenzene, substances for which H can be accurately calculated from solubility and vapor pressure data. The experimental and calculated H values given in Table I demonstratethe accuracy of tbe apparatus. The calculated H values wereobtained by dividing the vapor pressure (atm) by the solubility(g.mol m-: l ). Further runs were performed on systems forwhich H was unknown and the results of these experimentsare also given.

For acenaphthene and phenanthrene, the UV absorbancewas close to the lower limit at which accurate measurementis possible, and these results are thus suspect. A more accurateanalytical method is needed for compounds with solubilitiesbelow 5 g m-".

In all cases, the logarithm of the absorbance-time curve waslinear, except during the first few minutes of a run, in whichthere may have been surface effects or heterogeneous waterconcentrations. Once steady evaporation was established, nocurvature was observed. Tbis linearity indicates that H isconstant over the entire concentration range. It should benoted that the theoretical analysis presented earlier assumedthat the volume of the solute vapor formed is negligiblecompared to that of the stripping gas. This is generally valid

except possibly at the beginning of evaporation of high concentrations of volatile solutes in which the solute vapor volumecan be appreciable. This effect results in an initial curvatureto the absorbance-time line, and if desired, the equation forthe curve can be derived.

To investigate if the system is capable of elucidating ifsorption reduces volatilization rate (as is frequently claimedmay occur in natural waters), a series of tests was undertakenin which, during the volatilization of naphthalene, a smallquantity of concentrated aqueous suspension of fulvic orhumic acid was added. A typical result is given in Figure 5. Theconcentrations were measured in this case by fluorescence,since UV determination proved to be impossible due to interference. Tests showed that interference with fluorescencewas negligible.

Tbe fluorescence intensity (which is proportional to concentration) of the aqueous solution, measured directly to givethe dissolved naphthalene concentration, is shown on theupper lines. The dissolved concentration fell by a factor of 1.44on addition of 22 mg L-I of humic acid, implying 30% sorption.Equilibrium was apparently reached in 10 min, but it is possible that continuous concentration measurement could yielddata on the sorption kinetics. The lower lines illustrate thechange in total concentration as measured by liquid extractionof the sample and fluorescence intensity measurement of theextract. The log concentration vs. time curve changes slopeto a new value corresponding to an apparent reduction in Hby a factor of (l + Fl, where F is the ratio of sorbed to dissolved concentration. By measuring the displacement or slopechange of these curves, either for dissolved or total concentration, information can be obtained on the extent to whichsorption reduces volatilization rate.

Discussion

The results demonstrate that the gas stripping procedureis an effective means of measuring H for aromatic hydrocarbon-water systems. The H values were within 3% of valuesreported in the literature. In the other systems studied, anacceptable level of precision corresponding to a standard deviation of less than 6% was achieved. The method is believedto be the best available for measuring H oflow vapor pressurehydrophobic organic compounds. It has several advantagesin that it is fast (five determinations can be made in a 10-hperiod), it is inherently simple, and it requires measuring onlythe relative change in concentration (not the absolute concentration) in only one phase. In other systems, the absoluteconcentrations in hoth liquid and vapor phases must be determined.

The first part of this study was limited to compounds whichcould be analyzed hy UV spectroscopy and only those components with ahsorbances greater than ahout 0.2 could bestudied. As a result, H values for higher molecular weighthydrocarbons and chlorinated hydrocarbons could not bedetermined accurately. In the case of acenaphthene, for example,low absorbance readings gave poorly reproducihle results. It is suggested that for such compounds, more appropriate analytical procedures would be either fluorescenceanalysis or sampling of radiolaheled compounds with measurement of concentration by liquid scintillation counting.

The apparatus can be used to measure soluhilities if vaporpressure data are available. This may he the most accuratemethod of measuring solubility, since tbere are no prohlemsarising from the presence of dispersed or particulate organicsolutes, nor is there any need to prepare a completely saturated solution. The method also permits the determinationof vapor pressure data from solubility and H data. For ex-

ample, it is possible to calculate the vapor pressure of the solidhydrocarbons from the data in Table 1. Only for naphthaleneis solid vapor pressure data available. Although the systemdoes not achieve a complete approach to equilibrium, in mostcases the approach is satisfactory and the degree of approachcan be measured easily and, if desired, taken into account incalculating H.

The humic acid results suggest that the technique may beuseful in elucidating the extent to which sorbents reducevolatilization rates. By injecting a known quantity of organicor mineral sorbent, or an electrolyte, or another organic solute,it is possible to measure the change in volatilization rate.Several experimental techniques could be used, includingmeasurement of dissolved, total, or sorbed concentration, orthe gas-phase composition of one or more solutes, using absorption, spectroscopy, fluorescence, liquid scintillationcounting of radiolabeled solutes, or gas chromatography.Multiple concentration measurement has the advantage ofproviding mass balance verification. In principle, any technique which yields concentration data can be used to determine the effect of sorption on H, and even elucidate thesorption kinetics. In the case of electrolytes, the "salting out"effect will cause a steepening of the total concentration vs.time curve, corresponding to an increase in H and decreasein solubility.

When suspensions of organic or mineral matter are used,it is essential that all parts of the liquid are turbulent toeliminate the possibility of settling in quiescent regions. Lossof a small quantity of the liquid as spray is of little consequence since it does not alter the solute concentration. Ifsamples of the liquid are removed, the liquid volume (VI isreduced and the log concentration-time curve may becomenonlinear. Allowing for this effect in the calculation of H isstraightforward.

Cunclusions

A technique has been devised, tested, and verified for themeasurement of air-water Henry's law constants for hydropbobic solutes. The method is particularly suitable for lowsolubility, low vapor pressure solutes such as higher molecularweight hydrocarbons or halogenated hydrocarbons, for whichaccurate solubility and vapor pressure data may not beavailable or obtainable. It has been shown that the method hasthe potential to quantify the effect of sorbents and electrolyteson air-water equilibrium and possibly give some kinetic information on sorption processes.

Ulerature Cited

(I) Mackay, D., Leinonen, P. •J., Environ. Sci. Techno/.. 9, 1178(1975).

(2) Liss, P. S., Slater, P. G., Nature (D,md,ml. 247, 181 (1974).(3) Dilling, W. 1.., Tefertiller, N. R., Kallos, G. J., Environ. Sci.

Technol., 9,8:1:1 (1975).(4) Mackay, D., Shiu, W. Y., J. Chem. En/!. Data, 22,399 (1977).(5) McAuliffe, C., J. Phy". Chem., 70, 1267 (1966).(6) Aquan-Yuen, M., Mackay, D., Shiu, W. Y.,J. Chem. Eng. Data.

in press.(7) Weast, R. C., "Handbook of Chemistry and Physics", 5:1rd ed,

CRC Press, 1972-7:l.(H) Zwolinski, 1-1. ,J., Wilhoit, R. C., "Handhook of Vapor Pressures

and Heats of Vaporization of Hydrocarbons and Related Compounds'\ API, 44-TRC Puhlications in Science and Eng-ineerin!{,1H71.

Fleceivcd for revil'w May /(i. /978. Accepted Odober /2, /978. Theauthurs are ~ral(lful to Rnvironment Canada. Atmospheric Envi·ronment Service In/aod Woters Directorate. Imperial Oil Dimited,and the U.S. 8nvironmental Protl'ction A/1ency for financial supportof thi... work.


Lead Concentrations: Bats vs. Terrestrial Small Mammals CollectedNear a Major Highway

Donald R. Clark, Jr.

U.S. Fish and Wildlife Service, Patuxent Wildlife Research Center. Laurel, Md. 20811

• Meadow voles, white-footed mice, and short-tailed shrewswere trapped adjacent to the Baltimore-Washington Parkwayand also near Montpelier Barn, 0.61 km NW of the Parkway(Laurel, Prince Georges Co., Md.). Big brown and little brownbats were captured at their roosts in Montpelier Barn. Averagelead concentrations in bats generally exceeded those in terrestrial mammals, but levels in Parkway shrews did not differsignificantly from levels in bats. Concentrations in Parkwayshrews and white-footed mice exceeded those publishedpreviously for these two species. Estimated dosages of leadingested by little brown bats, Parkway shrews, and Parkwayvoles equalled or exceeded dosages that have caused mortalityor reproductive impairment in domestic mammals. Averagelead concentrations in bats and Parkway shrews equalled orexceeded those reported for small rodents that had been collected at abandoned mining sites in Wales with lead-inducedrenal abnormalities.

Numerous investigators have measured lead (Pb) concentrations in terrestrial small mammals collected near highways(1-9), but concentrations in bats from similar habitats havenot been measured. The present study compares lead concentrations of two species of bats and three species of terrestrial small mammals collected near a heavily traveled highway.

Materials and Methods

In 1976 the Baltimore-Washington Parkway carried 35000vehicles per day at its intersection with Maryland Highway197, Laurel, Md. (10). Rodents and shrews were snap-trappedalong the Parkway, within 18 m of the hard surface and within185 m south of Highway 197. Trapped were 20 meadow voles(Microtus pennsylvanicus; 8 females, 12 males), 20 whitefooted mice (Peromyscus leucopus; 9 females, 11 males), andsix short-tailed shrews (Rlarina brevicauda; 2 females, 4males).

Before it burned in December 1976, Montpelier Barn waslocated 0.61 km NW of the Parkway at its nearest point and0.84 km NNW of the Parkway trapping area. Trapped nearthe barn (within 91 m) were six meadow voles (four females,two males), five white-footed mice (two females, three males),and four short-tailed shrews (all females). All trapping at bothlocalities was done between May 21 and June 2,1976. Trapswere checked and reset twice daily. On May 24, 1976, 18 bigbrown bats (Eptesicus fuscus; 10 females, 8 males) and 12little brown bats (Myotis lucifugus, all females) were caughtby hand at their roosts in Montpelier Barn. A guano samplefrom each species was collected in the barn on January 7, 1976.The source of open water nearest the barn was 0.91 km ESEacross the Parkway. Each evening the emerging bats flewtoward this water and, therefore, toward the Parkway. All batsand terresterial mammals appeared to be adults except for sixjuvenile white-footed mice from the Parkway.

Upon collection, all mammals were taken to the PatuxentWildlife Research Center and frozen. Later they were thawedand the gastrointestinal tracts, and embryos of size sufficientfor analysis (= total litter weight> 0.36 g), were removed.Each litter was analyzed as a single sample. Samples ofstomach contents were pooled for analysis by species and 10-

cality. All samples were weighed, refrozen, and shipped to theEnvironmental Trace Substances Research Center, Universityof Missouri, Columbia, Mo., for analysis of lead content. Theocclusal tip width of the upper canine (canine tip width, CTW)of each bat was measured with an ocular micrometer in a 30Xdissecting microscope. This measurement is an indicator ofrelative age (11).

All mammals were analyzed whole except for removal of thegastrointestinal tract and large embryos. Each mammal (orsample of guano or stomach contents) was blended with anequal volume of distilled-deionized water to produce a homogeneous slurry, which was frozen until time for wet ashingwhen samples were thawed and shaken, and a subsample wasremoved. The subsample was digested with hot concentratednitric acid, cooked to near dryness, and then diluted to 25 mL.The solutions were analyzed by furnace atomic absorptionwith a Perkin-Elmer Model 403 atomic absorption spectrophotometer and a Model 2100 graphite furnace. All sampleswere run by the method of standard additions. For sampleswith high lead levels, solutions were analyzed by flame atomicabsorption with an Instrumentation Laboratories Model 453atomic absorption spectrophotometer. Nine percent of thesamples were checked by duplicate or triplicate analyses.Wet/dry ratios were determined by freeze-drying the portionsof slurries remaining after the lead analyses. Because the smallsamples from embryos, stomach contents, and some of themammals were entirely consumed by the lead analysis, dryweights are not available for all samples. Lead concentrationsare given as parts per million (ppm) of wet (= fresh) weightunless stated otherwise.

Geometric means and 95% confidence intervals are givenbecause of positive skewness in the lead data. However, thesame data are given as arithmetic means and standard errorsfor purposes of comparison with other published studies.Statistical separations of means were by Student's t or, whenvariances were unequal, by t' (12). Significance levels are asfollows: one asterisk, 0.05> P> 0.01; two asterisks, 0.01 > P> 0.001; and three asterisks, P < 0.001.

Results

Comparisons among Bats, Voles, Mice, and Shrews.Average lead concentrations in bats exceeded those in terrestrial mammals except for short-tailed shrews from theParkway, which contained more lead than did the little brownbats (Table I). However, the level in Parkway shrews was notsignificantly different from that in any of the t.hree bat groups;statistically this lack of difference resulted from the largevariance in levels among Parkway shrews. Amounts did notdiffer significantly with sex in the two groups of terrestrialmammals where samples were large enough to test (voles andmice from the Parkway), but the mean for females was largerin each instance.

Among the bats, male big browns had significantly morelead than females (t = 2.129*), and both sexes of big brownbats had significantly more lead than female little brown bats(t = 4.390*** for females and 5.42:1*** for males; Table I).Pooled samples of masticated insects from the stomachs of17 big brown bats and 12 little brown bats contained 3.8 and26 ppm of lead, respectively. Single samples of guano from bigand little brown bats contained 61 and 65 ppm of lead (dryweight).

338 Environmental Science & Technology This article not subject to U.S. Copyright. Published 1979 American Chemical Society

Table I. lead Concentrations (ppm Wet Weight) inBats, Rodents, and Shrews

Discussion

By utilizing arithmetic means based on dry weights, Icompared data for the terrestrial species with data from threeother studies (Table II). Concentrations in the short-tailedshrew and white-footed mouse exceeded those publishedpreviously, probably because traffic volume was heaviest inthe present study (Table II).

Quarles et at. (3) pointed out that shrews along highwayscontain greater levels than rodents for two principal reasons.First, because their metabolic rates are higher, shrews consume food, and therefore lead, at higher rates than do rodents.Second, the animal diet of shrews probably contains higherconcentrations of lead than do the plant diets of most rodents.The analyses of stomach contents in the present study supportthis latter contention.

It is not clear why bats roosting 0.61 km from the Parkwaycontained as much or more lead as voles, mice, and shrewscollected within 18 m of the Parkway. Perhaps the simplesthypothesis is that the bats' diets included enough heavilycontaminated insects from the Parkway so that this, coupledwith their high rates of food consumption, caused their totallead intake to equal or exceed that of even the shrews at theParkway. Although the analyses of stomach contents do notclearly support this hypothesis, these analyses are too few torule it out. Another plausible hypothesis is that the longer lifeexpectancies of bats could allow accumulation of more lead,but present data show no such trend. Also, these species ofterrestrial mammals may eliminate lead from their bodiesmore readily than do these bats; unfortunately there are nodata available on this point.

Big brown bats contained significantly more lead than littlebrown bats (Table I), and again several explanations seempossible. Big brown bats tend to be upland feeders (13) and,therefore, may bave caught more of their food near tbeParkway than did little hrown bats, which tend to feed nearwater (13). However, my limited data on stomach contentssuggested greater dietary intake of lead by little brown bats;analyses of guano showed similar levels. Big brown bats arrived at the barn earlier in the summer and left later than didlittle brown bats, and they may have caugbt a greater proportion of their total annual diet in the vicinity of tbe Parkway. Finally, little brown bats may eliminate lead more readily

Lead vs. Age. Six juvenile mice from the Parkway contained less lead (mean, 2.98 ppm; range, 0.99-7.2 ppm) thandid 14 adults (Table I), but the difference was not significant.Among the adult hats there were no significant correlationsbetween lead concentration and age as indicated by CTW.However, ranges for CTW were narrow (0.230-0.506 mm formale big brown bats, 0.230-0.460 mm for female big brownbats, and 0.046-0.253 mm for female little brown bats) andages may have been too similar to allow detection of any relationship.

1.45 (20)

0.99-2.120.22-5.0

4.91 (14)"2.17-11.110.36-41

Baltimore-WashingtonParkway

MontpelierBarn

46.55 (8)a

30.92-70.0620-90

16.97 (12)13.62-21.1411-29

1.16 (5)

0.20-6.78

0.32-13

0.84 (6)

0.55-1.270.46-1.4

31.49 (10)

25.70-38.5720-56

species

big brown bats (males)geom. mean95% conI. int.range

big brown bats (females)geom. mean95% conI. int.range

little brown batsgeom. mean95% conI. int.range

meadow volesgeom. mean95% cant. int.

Among the terrestrial mammals, concentrations weregreater at the Parkway, but the only significant differencebetween locations was for shrews (t = 2.991*; Table I). Differences among species at each site were significant only at theParkway (voles vs. mice, t = ~.191***; voles vs. shrews, t =6.708***; and mice vs. shrews, t = 2.489*; Table I). Pooledsamples of stomach contents from voles, mice, and shrews atMontpelier Barn contained 1.5, 1.0, and 6.8 ppm, whereas atthe Parkway they contained 9.4, 9.~, and 240 ppm of lead.

Lead in Embryos. Lead in bat litters averaged 0.16 ppmfor hi/( brown bats (N = 9 litters) and 2.38 ppm for little brownbats (N = 5 litters); the difference was not significant. Concentrations in litters were not significantly correlated witheither amounts in the female parent or with the weight of thelitter. Of course, the bats were killed about 1.5 to 3 weeks before parturition and embryonic development was incomplete.

Lead in two litters of voles was 0.11 ppm (Montpelier Barn)and 0.17 ppm (Parkway). A litter of mice from the Parkwaycontained 0.11 ppm.

rangewhite-footed mice

geom. mean95% can!. int.range

short-tailed shrewsgeom. mean 1.85 (4) 26.20 (6)

95% can!. int. 0.17-20.60 6.83-100.48range 0.23-8.0 6.2-130

a Sample size given in parentheses. b Six juveniles were excluded so that

this mean would be comparable to that for mice from near the barn.

Table II. Comparisons of lead Concentrations a in Whole Bodies b of Shrews, Mice, and Voles Collected within20 m of Highways with High Traffic Volumes

lead conens, ppm dry witrartie short·falled

ref and location vole shrews mlce d vole5 8

present study, f Laurel, Md. 35000 76.2 ± 48.3 (4)9 22.3 ± 8.2 (11) 6.1 ± 1.1 (20)ref 8, Blackburg, Va. 21040 34.8 ± 9.5 (3) 15.6 ± 1.2 (10)ref 7, Urbana, III. 19600 18.4 ± 1.5 (49) 6.3 ± 1.2 (18) 5.1 ±0.7(13)

ref 3, Charlottesville, Va. 12470 22.7 ± 7.9 (6) 6.8 ± 1.1 (7) 16.3 ± 1.4 (15)

a Arithmetic means and standard errors; standard errors for means in ref 3 and 7 were calculated from the authors' standard deviations. b Stomach contentswere removed in ref 8; the entire gastrointestinal tract was removed in the present study. C Vehicles per day. d The species was Peromyscus leucopus exceptin ref 7. where P. maniculatus was collected. e The species was Microtus pennsylvanicus except in ref 7. where M. ochrogaster was collected. ' Comparable

means lor bals were: male bi9 brown bats. 145.1 ± 29.3 (7): female bi9 brown bats. 105.6 ± 10.6 (10): female Iiltle brown bats. 48.7 ± 6.0 (11).• sample sizegiven in parentheses.


Table III. Minimum Dosages of Various Lead Compounds That Caused Mortality or Reproductive Impairment inSix S~ecies of Domestic Mammals

dosage,$p9c1•• compel of lead mg kg- 1 day-1 effects r.f

horses not indicated 2.4 "minimum chronic fatal dose" 25

cattle not indicated 6-7 "minimum cumulative fatal dose" 25

sheep acetate 1 of 10 pregnant sheep in "low condition", 1 died of illness, 3 aborted (1 of these 18died), 6 lambed normally as did a control group

sheep acetate 9 two pregnant sheep were dosed throughout gestation; they aborted and died on 19the 59th and 106th days

dogs carbonate 3 anorexia and convulsions began on 180th day 26rats nitrate 100,200 two of 16 young produced by 5 females receiving 100 mg kg- 1 died before 27

reaching 3 weeks of age; 8 of 16 young produced by 5 females receiving 200mg kg-' died before reaching 3 weeks of age

mice tetraethyl 1.5, 2.2, frequency of pregnancy was reduced by doses of 2.2 and 3.0 mg kg-' given on 28chloride and 3.0 days 3-5 after mating; frequency of implanted ova was reduced by dose of

1.5 mg kg- 1

than do big brown bats.!VIllle big brown bats contained significantly more lead than

females (Table I); the reason for this is unknown. My data forrodents, as well as other data for rodents (1), and for rodentsalld shrews (3) all show females with larger amounts, but nonepf these differences was significant. However, female Cali·fOfllia sea lions (Zalophus californianus) did contain signifiCilntly more lead than males (14).

Perhaps the principal question raised by the results of mystllqy is "What effect, if any, might the observed lead conce!ltrations have on these mammal populations?" Publishedillformation suggests that effects might include reproductiveimp1\irment, mortality, and renal abnormalities.

. Previous observations in Montpelier Barn showed thatstillborn bats were occasionally produced by both species.When pregnant females were caged shortly before parturition,19 and 11% of big brown bats (15, 16) and 28% of little brownbats (17) produced litters that included dead young. Stillbirths were most common among females of young age;therefore, they may have been natural rather than inducedby a toxic agent. Polychlorinated biphenyl (PCB) was experimentally ruled out as a cause in big brown bats (16). Therole of lead is unknown, but it has induced abQrtions in sheep(Table III; 18, 19).

Numerous studies with domestic mammals provide dataon minimum dosages that caused mortality or reproductiveijripairment (Table III). I calculated dosages to compare withthose in Table III by combining lead concentrations instpmach contents and weights of individuals captured in thisstudy with rates of food consumption as determined or estimated by other investigators.

Anthony and Kunz (20) found that pregnant little brownbats consumed approximately 2.5 g of food per day; this indicated a lead intake of 7.4 mg kg-1 day-I for the presentpopulation. Feeding data for big brown bats (13) led me toestimate a food intake of 5.2 g day-l and a lead intake of 1.0mg kg-I day-I for pregnant females. Buckner (21) determinedthat short-tailed shrews (in captivity) consumed 10.0 g of insects (larch sawflies, Pristiphora erichsonii) day-I; thistranslated to 128 mg kg-1 day-l of lead ingested by theParkway shrews. Meadow voles are thought to eat approximately 24.9 g day-l (22), whereas white-footed mice (in captivity) ate 4.29 g day-l (for 30 days at 20.5 °C) (23). Thesevalues translated to estimated daily intakes of lead of 6.0 and2.1 mg kg-1 for Parkway populations. Comparison of theseqosages with those of Table III suggested that mortality orreproductive effects might be expected, especially in theshort-tailed shrew, little brown bat, and meadow vole.

Lead-induced renal inclusions and renal edema occurredin rodents collected at abandoned metalliferous mine sites in


Wales; field voles (Microtus agrestis) with both abnormalitiescontained body burdens of lead that averaged 42.8 to 45.3ppm; renal edema occurred in field mice (Apodemus sylva.ticus) that averaged 8.60 ppm (24). Bats and shrews analyzedin my study (Table I) contained lead concentrations higherthan one or both of these sets of means from Wales, but thisevidence is only suggestive because no relationship betweentotal body burden and the development of renal inclusions oredema has yet been demonstrated (24).

Acknowledgments

I thank G. Chasko for assistance with trapping and preparation of specimens for analysis, E. H. Dustman and A. StanaFederighi for critical reviews of the manuscript, and T. H.Kunz for providing certain data and observations from his batstudies.

Literature Cited

(1) Jefferies, D. J., French, M. C., Environ. Pollut., 3, 147-56(1972).

(2) Williamson, P., Evans, P. R., Bull. Environ. Contam. Toxicol.,8,280-8 (1972).

(3) Quarles, H. D., III, Hanawalt, R 8., Odum, W. E., J. Appl. Ecol.,11,937-49 (1974).

(4) Mierau, G. W., Favara, B. E., Environ. Pollut., 8,55-64 (1975).(5) Raymond, R 8., Forbes, R 8., Bull. Environ. Contam. Toxicol.,

13,551-3 (1975).(6) Welch, W. R, Dick, D. L., Environ. Pollut., 8, 15-21 (1975).(7) Getz, L. L., Verner, L., Prather, M., Environ. Pollul., 13,151-7

(1977).(8) Goldsmith, C. D., Jr., Scanlon, P. F., Bull. Environ. Con/am.

Toxicol., 17,311-6 (1977).(9) Laerm, J., Carothers, S, W., Am. Midi. Nat., 98,250-4 (1977).(10) Coppage, D., Traffic Engineer, Prince Georges Co. Department

of Public Works and Transportation, personal communication,1977.

(11) Christian, J. J., Am. MidI. Nat., 55,66-95 (1956).(12) Snedecor, G. W., Cochran, W. G., "Statistical Methods", 6th ed.,

pp 104-6 and 114-7, Iowa State University Press, Ames, Iowa,1967.

(13) T. H. Kunz, Associate Professor of Biological Science, BostonUniversity, Boston, Mass.; personal communication, 1978.

(14) Braham, H. W., Enoiron. Pollut., 5,253-8 (1973).(15) Clark, D. R, Jr., Lamont, T. G., J. Wildl. Manage., 40,249-54

(1976).(16) Clark, D. R, Jr., Bull. Environ. Contam. Toxicol., 19,707-14

(1978).(17) Clark, D. R, Jr., Krynitsky, A., Pestic. Monit. J., in press.(18) Allcroft, R, Blaxter, K. L., J. Camp. Pothol., 60, 209-18

(1950).(19) James, L. F., Lazar, V. A., Binns, W., Am. J. Vet. Res., 27,132-5

(1966).(20) Anthony, E. L. P., Kunz, T. H., Ecology, 58,775--86 (1977).(21) Buckner, C. H., Can. J. Zool., 42,259-79 (1964).(22) Golley, F. 8., Ecal. Monogr., 30, 187-206 (1960).(23) Sealander, J. A., Jr., J. Mammal., 33,206-18 (1952).(24) Roherts, R D., Johnson, M. S., Hutton, M., Environ. Pollut.,

15,61-9 (1978).(25) Hammond, P. B., Aronson, A. L., Ann. N. Y. Acad. Sci., Ill,

595-611 (1963).(26) Staples, E. L. J., N. Z. Vet. J., 3,39-46 (1955).(27) Singh, N. P., Thind, I. S., Vitale, L. F., Pawlow, M., J. Lab. Clin.

Med., 87,273-80 (1976).(28) Odenbro, A., Kihlstrom, J. E., Toxicol. Appl. Pharmacol., 39,

359-63 (1977).

Received {or review July II, /978. Accepted October 18, 1978.

Analysis of Adsorption Properties and Adsorbed Species onCommercial Polymeric Carbons

William L. Filch and Dennis H. Smilh*1

Department of Gelletics, Stanford University, Stanford, Calif. 94305

• Research directed toward the analysis of polymeric carbonand materials adsorbed thereon is described. A new, simplemethod for measuring the adsorptivity of polymeric carbons,utilizing tritium-labeled benzo[a]pyrene, has been developedand used to compare the adsorptivities of 12 commercialpolymeric carbons. Benzene/methanol extraction and analysisby combined gas chromatography/mass spectrometry (GC/MS) indicate the presence of a series of oxidized polynucleararomatic hydrocarbons (PAH) as adsorbates on certaincommercial carbon black samples. Small amounts or no PAHwere detected in extracts of active carbons, graphite, andseveral other carbon blacks. The implications of this work forthe study of environmental polymeric carbons are discussed.

Polymeric carbons (also called graphitic or elemental carbons) are defined as those materials which consist structurallyof fused polycyclic ring systems composed predominantly ofcarbon. This definition encompasses a variety of polymersranging in homogeneity from coal and soot to graphite, butexcludes diamond. Polymeric carbons can be of natural origin(coal, graphite, soots from forest fires) or man-made (carbonblacks, fossil fuel derived soots, activated carbons). Polymericcarbons have been detected in all environments where theyhave been sought, including sediments (J, 2), the moon (3),and atmospheric particulates (4). In spite of its widespreadoccurrence, very little is known about the environmentalproperties of polymeric carbon (5).

The physical processes which produce polymeric carbons(6, 7) will also produce the lower homologues, the polynucleararomatic hydrocarbons (PAHs). These materials have knownhealth effects (8) and are routinely monitored in a variety ofenvironmental compartments. Of the commercial polymericcarbons, the soots such as lampblack and the carbon blacksused in rubber tire manufacture have been shown to containadsorbed PAHs which are extractable with benzene. However,the finer particle size channel blacks used for pigments andthe activated carbons used in water purification have not beenshown to contain benzene-extractable PAH in appreciablequantities. The similarities in production methods for thesedifferent carbons have led to the suspicion that the smallparticle size channel blacks and activated carbon will containadsorbed PAH, but that due to stronger adsorption thesePAHs are not extractable by usual methods. This paper willdescribe our methods for measuring the adsorption of PAHby polymeric carbon samples and the analysis of adsorbedspecies on commercial samples of carbon.

, I Present address, Department of Chemistry, Stanford University,Stanford, Calif. 94:105.

Experimental

Equipment. The gas chromatographs, mass spectrometer,and data analysis equipment routinely used in this laboratoryhave been described elsewhere (9, 10). Tritium was measuredwith a Packard Tri-Carb liquid scintillation counter. [3H]_Benzo[a]pyrene (158 /LCi//Lg in benzene) was purchased fromthe Amersham Corp. Samples of polymeric carbons were obtained from commercial sources as indicated in Table 1. Elemental analyses were performed by the Stanford Departmentof Chemistry Microanalytical Laboratory. Authentic samplesof PAH and derivatives were obtained from Aldrich ChemicalCo., Eastman Organic Chemicals, and Analabs Inc. All solvents were Baker "Resi-analyzed" grade.

Measurement of Benzo[a]pyrene Adsorption. [3H]_Benzo[a]pyrene solutions of specific activities 0.00123, 0.0510,1.37, and 158 /LCi//Lg in toluene were prepared from the purchased solution and unlabeled benzo[a]pyrene. These solutions are stable for several months at room temperature ifprotected from light. Aliquots were added to 10.0 mg of thepolymeric carbon sample in a small glass vial along with toluene to a final volume of 2.0 mL. Preliminary experimentsindicated that the adsorption was slow, requiring several hoursto reach equilibrium. For data collection, the adsorption experiments were left overnight prior to analysis. The solutionwas filtered through glass wool, and an aliquot of the filtratewas added to a scintillation vial containing Liquifluor scintillation fluid (New England Nuclear, 15 mL) for counting.The channel ratios method was used to correct the counts perminute for quenching. The equilibrium benzola]pyrene concentration in solution was then calculated from the specificactivity. The concentration of adsorbed benzo[a]pyrene wascalculated by subtraction using the known weights of carbonsample and benzo[a]pyrene added.

Extraction and Analysis of Carbon Samples. A polymeric carbon sample (5 g) was extracted for 20 h in a standardsoxhlet apparatus with benzene/methanol (9:1). The residueafter removal of the solvent was weighed and dissolved in dichloromethane and the internal standard, 1,2,3,4-tetrachloronaphthalene (200 /Lg), was added. An aliquot of this solutionwas injected on a 6 ft X 'Is in. packed column of Dexsil 300along with a mixture of hydrocarbon standards (CIG, C20, C2S,

and C3G, about 1 /Lg each). The column was programmed from120 to 300°C at 4°C/min. A total of 500 mass spectra wererecorded with a mass range of 40-450. For the higher molecular weight PAH present in certain extracts, it was necessaryto record 700 spectra to a final temperature of 325°C.

Data Analysis. The raw data from the GC/MS experimentswere analyzed by the suite of computer programs, CLEANUP,TIMSEK, and SEARCH, which have been described elsewhere(9, 11). The CLEANUP program produces "clean" mass spectraof components after subtracting background and resolvingoverlapping peaks. The TIMSEK program assigns relative re-

0013-936XI79/0913-0341$Ol.00/0 © 1979 American Chemical Society Volume 13, Number 3, March 1979 341

Table I. Polymeric Carbons Investigated

particletrade name size, nm

channel 19 b Colour Black FW200 13channel 18 c Neo Spectra AG 13channel 15 b Colour Black FW2 13channel 13 b Special Black 5 20channel 12 b Special Black 4 25channel 10 c Neo Spectra Mark 111 14channel 4 b Colour Black S160 20active 9 a Darco G60active 8 d NoritAfurnace b Corax L 23lampblack a Lampblack 44graphite a Power Grade 38 <44000

I"·~o."

··~

1Log Benzo(aJpyrene In solution (og mIl

Figure 2. Data of Figure 1 presented as the distribution ratio of benzo[a !pyrene (solution/carbon. see text for details) vs. benzo [a1pyreneadsorbed on carbon

Figure 1. Partition of benzola !pyrene between 10 mg of channel black13 and 2 mL of toluene. expressed as log concentration on carbon vs.log concentration in solution

carbons listed in Tahle I was extracted with benzene/methanolfor 20 h. The percent extractahle material is listed in TableII. The extracts were analyzed by combined gas chromatography/mass spectrometry to determine the chemical natureof the adsorbed species (12). The total ion current traces forthe extracts of the lampblack and three channel blacks areshown in Figures 3-6. The identities of individual componentswere determined by comparison of both mass spectra andrelative retention indices to those of authentic samples, bycomparison to literature spectra (13-/5), or by analysis offragmentation patterns (16, /7). The quantitative results(Table III) are based on the calculation of relative concentrations by the TIMSEK program (9) using tetrachloronaphthalene as internal standard.

Table III lists quantitative data on the extractables fromfive channel hlacks and a lampblack. The data are presentedonly for the most ahundant member of each compound classfor each polymeric carbon. The actual number of compoundsquantitated from each carbon is too large for tabular presentation. A complete listing of all of the compounds which wehave detected in these studies. together with their relativeretention indices on Dexsil300, has been published elsewhere(18). The relative ret.ention indices which we measured arein good agreement with a previously published list of RRIvalues for PAH on Dexsil :.l00 (19). We have not attempted to

I!/

/. ~/.-.-.-...~----

100 10000adsorbed (ng/mg)

0.01 1.0

Benzo(aJ pvrene

2.1.~

·c0

0 1.5<>

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~0

c0.3·"'

II Fisher Scientific Co. 0 Degussa Inc.. Pigments Division. C Cities ServiceCo., Columbian Division. d Matheson Coleman and Bell.

Table II. Analytical Data on Polymeric Carbons

elemental anal. adsorp-name C H N S 0 ash extract a tivity b

channel 18 81.3 0.5 0.0 0.1 18.0 0.1 <0.1 0.030channel 19 79.2 0.7 0.4 0.4 19.4 0.0 1.4 0.056active 8 88.0 0.6 0.1 00 7.6 3.7 <0.1 0.060channel 15 83.9 0.3 0.4 0.3 14.9 0.1 1.1 0.069channel 10 89.5 0.7 0.0 0.0 9.8 0.0 <0.1 0.072active 9 88.7 0.7 0.0 0.0 8.8 1.8 <0.1 0.083graphite 97.0 0.1 0.0 0.0 1.6 1.3 <0.1 0.14channel 13 85.6 0.6 0.3 0.4 13.2 0.0 0.85 0.15furnace 96.9 0.3 0.0 0.7 2.1 0.0 <0.1 0.23channel 12 86.0 0.7 0.4 0.4 12.4 0.0 0.48 0.36channel 4 94.6 0.6 0.1 0.3 4.4 0.0 1.0 3.8lampblack 96.7 0.6 0.0 1.5 0.9 0.3 0.37 40.0

;1 Weight percent of the benzene/methanol extract. b Distribution coefficientfor 10 n9 of benzol alpyrene between toluene (2 mL) and carbon (10 mg). Results

in units of nanograms per mL of toluene per nanograms per mg of carbon.

tention indices (RRI) to each peak by comparison to coinjected hydrocarbon standards. and calculates relative concentrations in comparison to the added internal standard. TheSEARCH program attempts to identify peaks hy comparisonof mass spectra and associated RRI's to a library of previouslyidentified compounds. This library is continuously updatedand now contains over 100 spectra of PAH and derivatives.


Adsorption of Benzo[a]pyrene by Polymeric Carbons.We have measured the adsorption of [:lH!benzo[a!pyrene fromtoluene by the channel hlack sample 13 (Table I; the numbersrefer to oxygen content) over a broad range of concentrations.The resulting adsorption isotherm plotted as the logarithmof the adsorbed concentration vs. the logarithm of the equilibrium toluene concentration is shown in Figure 1. Anotherway oflooking at theRe data is presented in Figure 2. Here theratio of the solution concentration to that adsorbed is plottedagainst the logarithm of the adsorbed concentration. It canbe seen that the distrihution of benzo[a !pyrene is constant upto an adsorbed concentration of about 10 ppm. It was decidedto compare the adsorptivities of variouR carbons at the I-ppmlevel. These results are shown in Tahle II and are discussedbelow. It is felt that this simple method is a reliable way ofmeasuring the adsorptive capacities of various polymericcarbons for PAH.

Identification of Carbon Extractables. Each of the


Table III. Quantitative Analysis of Carbon Black Samples: Concentration (ppm) of Most Abundant Member ofEach Chemical Class

class lampblack channel 4 channel 12 channel 13 channel 15 channel 19

PAH pyrene, 302 phenanthrene, phenanthrene, 12 phenanthrene, 18 phenanthrene, 32 phenanthrene, 12470

heterocycles benzo[defJ. dibenzoluran, dibenzofuran, 11dibenzothio- 190phene,70

nitro-PAH 1-nitronaphtha- a nitrophen- 1-nitronaphtha- 1-nitronaphtha-lene,15 anthrene, 15 lene,46 lene,24

oxy-PAH benzoldef]pyren- 9-lluorenone, 218 9-lluorenone,21 anthraquinone, 9-f1uorenone, 53 anthraquinone,one, 26 23 63

anhydrides naphthalic, 161 naphthalic, 62 naphthalic, 137 naphthalic, 79 naphthalic, 79carboxy-PAH phthalic, 90 phthalic, 306 phthalic, 302 phthalic, 668

determine which among many possible isomeric structuresis present for many of the materials which occur at low concentrations.

Properties of Specific Polymeric Carbons. (a) Graphite.The majority of the graphite in commercial use is preparedsynthetically by high-temperature conversion from less purecarbon black or coke. Small organic molecules will not survivethe high temperatures involved in graphite formation. Extraction of a commercial powdered graphite sample yieldedtrace quantities of naphthalene, but no other extractables. Theabsorbency of graphite for benzo[a jpyrene (Table II) indicatesthat particle size (and thus external surface area) is not theonly factor regulating adsorption. Although the particle sizeof our graphite sample far exceeds that of other carbon samples, its adsorptivity for benzo[a ]pyrene is intermediate tosamples with much smaller particle sizes.

(b) Active Carbon. Activated carbons are prepared bycontrolled pyrolysis and subsequent oxidative activation oforganic substrates, such as wood, coal, or petroleum residues.Their high adsorptive properties are due to the highly porousstructure formed during the oxidation process. A large increase in the production of activated carbons has been predicted for the next several years (20) due to EPA mandateduse in water treatment programs. The large scale use of thesematerials will necessitate a greater understanding of theiradsorptive/desorptive (21, 22) and catalytic (23) properties.As prepared, active carbons have at most trace quantities ofextractable organic adsorbates (24). We extracted two commercial active carbons and were able to detect only tracequantities of low molecular weight PAH in one of the twosamples. Although our experiments with active carbons didnot yield extractable PAH of significance, it should be pointedout that these carbons are not those of primary interest in thearea of wastewater treatment. Rather than take our data asevidence for the lack of readily extractable PAH on activecarbon, we suggest that other workers investigate other activecarbons of greater commercial interest. The variability inextractable materials on other, closely related carbons suggeststhat other active carbons may well possess extractable materials.

Both of these carbons strongly adsorbed benzo[a ]pyreneas expected. Active carbons tend to be irreproducible frombatch to batch in their adsorbency for water pollutants (25),and simple ways of measuring this property are of value. Thismethod utilizing tritiated benzo[a]pyrene can be readilyadapted to study the adsorptive capacity of active carbon forthis PAH in the presence of complex organic matrices suchas humic material (26). This measurement would be difficultby conventional chromatographic or spectroscopic techniques.

Similar techniques utilizing more relevant solvents (e.g.,water) and more environmentally critical pollutants (e.g.,

trihalomethanes) can be envisaged for quality control applications in the water treatment field.

(c) Carbon Blacks. Carbon blacks are a variety of materials,composed of microcrystalline graphite-like particles, whoseproperties vary greatly depending on their method of preparation (27,28). The major forms include the following.

(1) Lampblack. Historically the classic black pigment foruse in printing, lampblack is now largely replaced by furnaceand channel blacks. Lampblack is prepared commercially byincomplete combustion of heavy petroleum fractions. Theproducts have particle sizes ranging from 40 to 200 nm andnormally contain large amounts of adsorbed polynuclear aromatics. On extraction, a commercial lampblack sampleyielded a variety of PAH and sulfur-containing PAH as shownin Figure 3 and Table III. The adsorptivity of lampblack forbenzo[a]pyrene (Table II) is very low, supporting the idea thatany PAH present will be readily extractable.

(2) Furnace Black. This is the black produced in largestvolume at the present time. It is used primarily in rubberproducts including tires. These blacks are prepared in largefurnaces from petroleum fractions and an additional energysource such as natural gas. Their properties vary greatly depending on feedstock and process technology. Particle sizesrange mainly from 20 to 50 nm. Furnace blacks, includingthose of particle size near 30 nm, have been shown to containadsorbed PAH and sulfur and oxygen derivatives (15, 29-32).However, the small particle size furnace black which we extracted yielded only traces of the smaller PAH, pyrene beingthe highest molecular weight derivative detected. A trace ofdibenzofuran was also detected.

(3) Channel Blacks. These fine particle size blacks (10-30nm) are prepared by impinging natural gas or petroleum basedflames on moving metal channels. The channel blacks are themost expensive of the commercial blacks and find their usein fine pigments. To achieve maximum color properties, manychannel products receive a postoxidative treatment. Theoxygen content of a channel black can range up to 20%.

According to the literature, channel blacks do not containextractable PAH (29, 33, 34). Indeed, it was reported thatsmall particle size channel blacks are so strongly adsorptivefor PAH that they would not be readily detected even ifpresent (35). Our results on the adsorption of [:IH]benzo[a]pyrene by channel blacks (Table II) confirm this. The smallparticle size, high oxygen content channel blacks adsorbbenzo[a]pyrene as strongly or more strongly than activatedcarbons. We have, however, detected a series of PAH derivatives upon extraction of these channel black samples.

Figures 4 and 5 show the total ion current traces for theextracts of two oxidized channel black samples, channel 12(Figure 4) and channel 15 (Figure 5). Phenanthrene is seen inthese extracts, but no other PAHs are detectable at this levelof sensitivity. However, a variety of oxidized species common


"

~VI

Ih

~I

";vI

vI

~I

Figure 3. Reconstructed total ion current trace obtained from GC/MS analysis of the benzene/methanol extractable material from lampblack

..~ ~

~ ~ (ng 8

b ¥ ~ <S'

~z

}8 , A

~ON , Az

c]O hrt~~.' cg• A ~.l",,".~n

~1;, g'B ' A

Figure 4. Reconstructed total ion current trace obtained from GC/MS analysis of the benzene/methanol extractable material from channel black12

to both channel blacks have been identified. 'These includeketones such as 9-fluorenone, quinones such as anthraquinone, nitro compounds such as I-nitronaphthalene, anhydrides such as 1,8-naphthalenedicarboxylic anhydride, andmethyl esters such as dimethyl phthalate. 'The methyl esterswere not detected when benzene alone was used for extractionand are presumably formed by acid-catalyzed (these channelblacks are highly acidic) esterification with the methanolsolvent. Channel samples 19 and 13 yielded similar results.In general, the four oxidized channel blacks which WP. obtainedfrom Degussa Inc. showed increasing extractable content withincreasing oxygen content.

Interestingly, the two high oxygen content, high benzo[a 1pyrene adsorption, small particle size channel blacks whichwere obtained from the Cities Service Corp., Columbian Division (channels 18 and 10, 'Tables I and II), had no detectableextract at all. 'The only noticeable difference in these blacksis that they have much lower sulfur and nitrogen contentsindicating differences in petroleum feedstock or postoxidationtechnology or both. 'This discrepancy is typical of commercialproducts for which the quality control and marketability are


based on nonchemical criteria, such as color.'The lowest oxygen content channel (channel 4, also a De

gussa product) yielded an extract (Figure 6) which containedboth PAH and oxidized PAH. However, it did not show eitherthe methyl esters or the nitro-PAH. Among the channels investigated, this sample was the only one which does not receivea postoxidative treatment during its production. Thus, wespeculate that the more highly oxidized PAH acids and nitroderivatives are formed during this high-temperature, air oxidation. Channel 4 is also anomalous in its adsorption ofbenzo[a]pyrene compared to other samples of similar particlesize.

As mentioned, the small particle size channel blacksstrongly adsorb benzo[a jpyrene and presumably other PAHsas well. 'The oxidized PAHs, which appear to be readily extracted from these carbons, generally have molecular weightsin the 170-230 range. Whether higher molecular weight materials are present but not extractable is now known. We havedetected trace quantities of oxy-PAH with molecular weightsup to 270. Approaches to improving the extraction of PAHfrom carbon blacks are described elsewhere (10).

('''''Nlll!;

moo

'"r"';r-COOM.~COOMe

'"

,so

Figure 5. Reconstructed total ion current trace obtained from GC/MS analysis of the benzene/methanol extractable material from channel black15

moo

'"

"

8-~

• A

~~

I -, b

<"

". <S. '"Figure 6. Reconstructed total ion current trace obtained from GC/MS analysis of the benzene/methanol extractable material from channel black4

(d) Soots. Any incomplete combustion process will producea residue of polymeric carbon. The major environmentalconcerns here are soots from motive or electrical energy production and uncontrolled fires. These soots are of undetermined structure and are admixed with a variety of other pollutants. It is likely that the PAH and derivatives, includingketones, quinones, and acids which have been detected inatmospheric particulates (19, 36, 37), are associated with thepolymeric carbon present. We have not investigated any environmental soots at this time.

Conclusions

Polymeric forms of carbon are widespread environmentalcontaminants. Very little is known about their fate in the airor on land. Furthermore, little is known about the adsorptiveand catalytic properties of these carbons with respect to materials with which they are likely to occur, such as PAH orsulfur dioxide. Our results on the extractable components ofchannel blacks indicate that the polar PAH derivatives are

more prevalent and more readily solubilized than PAH forcertain carbons. Whether these oxidized PAHs demonstratethe same cellular toxicities as their parent molecules is unknown. The recent investigations of the mutagenic propertiesof nitro derivatives of benzo(ajpyrene (38) certainly indicatethat more work is needed in this area.

Finally, our work has particular relevance to one area ofhealth concern. In 1976, the FDA removed carbon black fromthe GRAS list for food and cosmetic additives (39). The primary rationale for this delisting revolved around the questionof the presence of extractable PAH. Previously, only channelblacks had been allowed for food uses as these supposedlycontained no PAH. The introduction of channel blacks utilizing varied petrocarbon feedstocks led to worries aboutquality control. Channel black producers were unable to satisfy the FDA as to the consistent nature of their products. Asour results demonstrate, materials of competitive colorproperties can vary tremendously in terms of extractablecontent. Very careful regulation will be required if carbonblacks are to be relisted as food and cosmetics additives.


Literature Cited

(I) Bertine, K. K., Mendeck, M. F., Environ. Sci. Technol., 12,201-7(1978).

(2) Smith, D. M., Griffin, J. J., Goldberg, E. D., Anal. Chem, 47,233-8 (1975).

(3) Chang, S., Smith, J. W., Kaplan, I., Lawless, J., Kvenvolden, K.A., Ponnamperuma, C., Proc. Apollo 11 [Eleven ILunar Sci. Conf.,2,1857 (1970).

(4) Rosen, H., Hansen, A. D. A., Guridel, L., Novakov, T., Proc. Conf.Carbonaceous Particles Atm., in press (March 1978).

(5) Schneour, E. A., Science, 151,991-2 (1966).(6) Lahaye, J., Prado, G., ACS Symp. Ser., No. 21, 333-46 (1976).(7) Abrahamson, J., Nature (London), 266,323-7 (1977).(8) National Academy of Sciences, "Particulate Polycyclic Organic

Matter", Washington, D.C., 1972.(9) Smith, D. H., Achenbach, M., Yeager, W. J., Anderson, P. A., Fitch

W. L., Rindfleisch, T. C., Anal. Chem., 49, 1623-32 (1977).(10) Fitch, W. L., Everhart, E. T., Smith, D. H., Anal. Chem., in

press.(I I) Dromey, R. G., Stefik, M. J., Rindfleisch, T. C., Duffield, A. M.,

ibid., 48,1368-75 (1976).(12) Lao, R. C., Thomas R. S., Monkman, J. L., J. Chromatogr., 112,

681-700 (1975).(13) Eight Peak Index of Mass Spectra, Mass Spectrometry Data

Centre, AWRE, Reading, RG74PR, U.K., 1974.(14) Markey, S. P., Urban, W. G., Levine, S. P., "Mass Spectra of

Compounds of Biological Interest", U.S. Atomic Energy Comm.Rep. No. TID-26553, National Technical Information Service, U.S.Dept. of Commerce, Springfield, Va.

(15) Gold, A., Anal. Chem., 47, 1469-72 (1975).(16) Budzikiewicz, H., Djerassi, C., Williams, D. H., "Mass Spec

trometry of Organic Compounds", Holden-Day, San Francisco,Calif., 1967.

(17) Shapiro, R. H., Serum, J. W., Org. Mass Spectrom., 2,533-9(1969).

(18) Fitch, W. L., Smith, D. H., Proc. Conf. Carbonaceous ParticlesAtom., in press (March, 1978).

(19) Cautreels, W., Van Cauwenberghe, K., J. Chromatogr., 131,253-64 (1977).

(20) Chem. Eng. News, 10-2 (April 3, 1978).

NOTES

Microbial Release of Oil from Soil Columns

(21) Garten, V. A., Weiss, D. E., Rev. Pure Appl. Chem., 7,69-122(1957).

(22) Hassler, J. W., "Purification With Activated Carbon", ChemicalPublishing Co., New York, N.Y., 1974.

(23) Ishizaki, C., Cookson, J. T., J. Water Pollut. Control Fed., 45,515-22 (1973).

(24) Borneff, V. J., Fischer, R., Arch. Hyg., Bakteriol., 145,334-9(1961) (German).

(25) Bishop, D. F., Marshall, L. S., O'Farrell, T. P., Dean, R. B.,O'Conner, 8., Dobbs, R. A., Griggs, S. H., Villiers, R. V., J. WaterPollut. Control Fed., 39,188-203 (1967).

(26) Snoeyink, V. L., McCreary, J. J., Murin, C. J., EPA Rep. 600/2-77-223, Dec 1977.

(27) Mantell, C. A., "Carbon and Graphite Handbook", Interscience,New York, N.Y., 1968.

(28) Ban, L. L., Hess, W. M., ACS Symp. Ser., No. 21, 358-77(1976).

(29) Falk, H. L., Steiner, P. E., Cancer Res., 12,30-9 (1952).(30) Lee, M. L., Hites, R. A., Anal. Chem., 48, 1890-3 (1976).(31) Qazi, A. H., Nau, C. A., Am. Ind. Hyg. As.oc. J., 36, 187-92

(1975).(32) Wallcave, L., Nagel, D. L., Smith, J. W., Waniska, R. D., Environ.

Sci. Techno!., 9, 143-5 (1975).(33) Steiner, P. E., Cancer Res., 14, 103-LO (1954).(34) Neal, J., Thornton, N., Nall, C. A., Arch. Envirvn. Health. 4,

46-54 (1962).(35) Falk, H. L., Steiner, P. E., Cancer Res., 12,40-5 (1952).(36) Pierce, R. C., Katz, M., Environ. Sci. Technol., 9, 347-53

(1975).(37) Pierce, R. C., Katz, M., ibid., 10,45-51 (1976).(38) Pitts, J. N., Van Cauwenberghe, K. A., Grosjean, D., Schmid,

J. P., Fitz, D. R., Proc Conf. Carbonacevus Particles Atmosphere,in press (March 1978).

(39) Food and Drug Administration, Color Additives, Fed. Regist ..41,41852 (Sept 23,1976).

Received for review June 12,1978. Accepted October 23,1978. Theseresults were presented at the Conference on Carbonaceous Particlesin the Atmosphere, Berkeley, Calif., March 1978. This research wassupported by a grant from the Natiollol Aeronautics and SpaceAdministratiun (NGR-05-020-004).

Rudi Vanloocke, Anne-Marie Verlinde, and Willy Verstraete

University of Ghent, Coupure 533, 9000 Gent, Belgium

Raymond De Borger"

Chemical Research Institute, Museumlaan 5, 1980 Tervuren, Belgium

• The possibility of cleaning up subsurface soil horizonspolluted with gas oil by activating microbial processes hasbeen investigated. The results obtained from the laboratorystudies indicate that by irrigating the soil with a nutrient solution containing ammonium nitrate and peptone, 10-20% ofthe oil adsorbed in the soil can be recovered in a period of 3-4months. The release process is biological. The recovered oilis not emulsified and can be recuperated as a phase.

When large quantities of oil are spilled on land, the pollutant penetrates the underlying soil layers and eventually formsan oil lens on top of the groundwater table. Fluctuations of thegroundwater table result in a smearing out of the oil over alarge volume of subsurface soil. In contrast to the oil adsorbedin the A-horizons, the oil thus retained in the underlying horizons only degrades slowly and, furthermore, only partially.However, percolating rainwater and migrating groundwatergradually leach out the oil components and their breakdown


products. Since parts per million levels of oil products sufficeto make water undrinkable, it is clear that a subsurface oil lenscan pollute large volumes of groundwater for years and evendecades.

Several remedies have been proposed: mechanical excavation of the soil horizons, confinement of the oil in a groundwater depression by lowering the groundwater table in thepolluted area, and finally leaching of the soil with detergentsolutions (1, 2).

The bioemulgation of oil components under anaerobicconditions in soil layers has been reported by La Riviere (3).More recently, Reisfield et al. (4) and Zajic et al. (5) haveshown that, in oil-water emulsions, bacteria can enhance thedispersion of the oil into the aqueous phase by the formationof emulsifying agents. Several laboratories have studiedmethods to recover, by means of microbial processes, oilremnants from exhausted fields (6, 7). The purpose of thisresearch was to evaluate the possibility of decontaminatingsubsurface soil horizons by activating microbial desorptionprocesses in these soil layers.

0013-936XI79/0913-0346$01.00/0 © 1979 American Chemical Society

Table I. Characteristics of the Gas Oils Examined 3

Table II, Oil Retention Capacity as a Function of Oiland Soil Type (g Retained/kg Air-Dry Soil)

Table III. Average Composition of the Effluents of theLysimeter over a Period of 15 Weeks and Total GasOil Recovery

physical properties Bachaquero Kuwait

viscosity (cP), 22°C 12.0 4.0density, 22°C 0.888 0.833composition (% by wt)

aliphatics 59.2 62.0

aromatics 32.9 23.0

soluble N, S, °fraction 3.0 2.9

insoluble N, S, °fraction 48 11.8

Fig~re 1. Lysimeter apparatus to study the leaching of oil out of soilcolumns(1) Air scrubbing with water; (2) air scrubbing with methyl bromide; (3) threeway valve; (4) fertilizer solution; (5) sprinkler; (6) Iysimeter column; (7) drainage system; (8) effluent collector; (9) buffering bottle; (10) manometer; (11)vacuum pump

topped gas 011

90.6 84.563.3 41.2

Bachaquero Kuwait

AB

soil horizon

lolal fatty free fatty N02- + total %matter, acids. N03- -N, phosphate, gas oil

treatment mg/l mg/L mg/L mequiv/l recovered

distilled water 43 1.0 7 0.2 0.0LABS 89 2.7 50 0.1 0.1NH4N03 + KH 2P04 1835 6.8 2700 0.2 2NH4N03 + 3578 2000 0.1 3

glycerophosphateNH4N03 + Et3P04 9532 20.0 2005 0.4 10NH4N03 + peptone 14924 34.0 23 <0.1 14

Experimental

Apparatus. Glass columns 1.0 m in height and 0.2 m indiameter were set up as lysimeters according to Cassel et al.(8) (Figure 1).

Procedure. Thirty kilograms of air-dried soil was packedinto a glass column. The column was subsequently irrigatedwith water. After 2.0 L of water had percolated through, 2.0L of gas oil, from which the volatile fraction had been removedby aerating the oil at room temperature for I week, was applied to the top of the column. Then the leaching procedurewas started by applying 0.5 L of an aqueous solution 3 timesa week. The soils and the effluent were analyzed as describedbefore (9).

Materials. The soil used was an acidic black podzol (AquicHaplohumod). The principal characteristics of the topped gasoils used in this study are given in Table I. Triethyl phosphatewas obtained from Aldrich Europe, Beerse, Belgium. Glycerophosphate was synthesized in the laboratory from glyceroland polyphosphorous acid. The latter two chemicals were lIsedin an attempt to enhance the removal of oil from the soil.

Results

An initial investigation to select an appropriate modelsystem revealed that the oil retention capacity varied considerably with the type of oil and soil (Table II). ToppedKuwait gas oil tended to leach out to a larger extent from thesoil columns than the more viscous Bachaquero gas oil. [naddition, the retention of oil in the A-horizon of the podzol wasmore firm than in the B-horizon. Therefore, the variousmethods to activate oil desorption were tried out on the systemwith the highest apparent oil sorption capacity, i.e., soil fromthe A and sub-A horizons saturated with topped Bachaquerogas oil.

kg gasoil leached/m2

7,5

5.0

2,5

.................... 10 weeks ..... ·i's

Figure 2. Oil leached out of soil columns(...)Distilled water; (- - -) NH4N03 + KH2P04;(- -) NH4N03+Et3P04; (-)NH4N03 + peptone

Lysimeters containing soil from the A-horizon treated withBachaquero gas oil steadily released small amounts of hydrocarbons when they were irrigated with distilled water(Table III). The water was not turbid but it had a repugnantodor.

Somers and Drok (10) obtained an optimal oil mobilizationby applying a 1%0 solution of a linear alkylbenzenesulfonate(LABS) detergent. The soil columns which were treated withsuch a detergent solution released only minor amounts of oil(Table III). Furthermore, the effluent obtained had theproperties of a stable oil-in-water emulsion.

A rather intensive release of oil was observed in soil treatedwith a fertilizer solution containing 2100 mg of NO;)- -N, 2100mg ofNH 4+-N, and 42 mequiv ofP04;t- per L After 4 weeks,considerable amounts of oil began to appear in the columneflluent (Figure 2). After 15 weeks, the oil release graduallydecreased. During the whole period, the oil was not emulsifiedand could easily be skimmed off the aqueous effluent. Toverify if the effect was of a biological nature, control experi-


ments were set up in which the soil columns were regularlyfumigated with methyl bromide. In these experiments, no oilwas leached out of the soil column~ after repeated irrigationwith fertilizer solutions. From this it was concluded that themobilization of the oil components out of their physicochemical soil entrapment must be due to microbial activity.

Some additional columns were studied with regard to theinfluence of the suction and of the fertilizer concentration. Theset-up according to Cassel et al. (8) provides a suction of 300mmHg which corresponds with a groundwater table at a depthof ±6.0 m. When this suction was lowered to 200 mmHg, theamount of oil released dropped to one· tenth. In addition, alllevels of Nand P below those reported gave only a negligiblerelease of oil. Finally, it was also observed that considerablyless desorption occurred when the treatment procedure waspostponed a few weeks after the application of the oil to thesoil column.

Since orthophosphate has a low mobility in the soil, threetypes of organic phosphate were tested. A solution containingglycerophosphate (42 mequiv/L) and NH4NO" (4200 mg ofNIL) enhanced the oil release significantly. Even better resultswere obtained with a solution containing triethyl phosphate(42 mequiv/L) and NH 4NO" (4200 mg of NIL). The most interesting finding, however, was that a solution containing 50mg/L peptone in addition to 100 mg/L NH4NO:I-N sufficedto bring about an oil release which surpassed the ones obtainedwith concentrated chemical solutions. It should be noted thatjust as with the inorganic fertilizers, the effluent separated intodistinct oil and aqueous phases. After the 13th week, the effluent was, when analyzed by IR spectroscopy, practically freeof hydrocarbons. At the end of the latter treatment, the soilof the lysimeter column was analyzed. From the 1780 g of oilapplied, 1375 g was found after 15 weeks. Since some 230 g wasrecovered in the effluent, about 175 g or 10% was most probably metabolized by the soil microbiota.

Discussion and Conclusions

In these model experiments, a rather difficult case of pollution was selected, namely a viscous type of oil, spilled at ahigh rate (75 L or 67 kg per m~) on a soil with a high retentioncapacity. The techniques which have been investigatedcomprise two physical components, that is, irrigation with anutrient solution and application of a negative pressure to thesoil aqueous phase. The suction applied to the columns corresponds to a water table at a depth of 6 m. This can beachieved in the field by the use of suction pumps. The irrigation rate applied in the laboratory is also quite achievableunder field conditions since it corresponds to ±2.400 mm m-~

year-I. However, it must be recognized that in tbe field theinternal drainage rate might become tbe limiting factor. Inaddition, tbe soil system studied was much more homogeneousthan the ones one can expect in practice. Hence, the resultsobtained cannot be directly extrapolated to the field, but theyindicate the desorption of oil which potentially can be obtained in soil layers under advantageous physical and biological conditions.

Of the chemicals tested, LABS turns out to be totally ineffective. A limited release of oil was obtained with (NH4NO:1

+ KH~P04) and with (NH4NO:1 + glycerophosphate). Aconsiderable desorption occurred, however, for the treatments(NH4NO" + Et:IP04) and (NH4NO:1 + peptone). From TableIII it is clear that the latter treatment is preferable. Indeed the(NH4NO:1 + Et:Y04) treatment requires large amounts ofchemicals and it gives an effluent which is highly loaded with


NO:I- and furthermore contains traces of residual Et:1P04. Incontrast herewith, the (NH4NO:1 + peptone) treatment requires small amounts of chemicals and it produces an effluentwith low levels of residual nitrate. Triethyl phosphate cannottotally be rejected as a mobile source of phosphorus, however.Indeed, for soil columns with depths surpassing several meters, it might turn out that the latter chemical is more mobileand effective than peptone.

The experiments with fumigated soil clearly establish thebiological nature of the oil desorption phenomena. In thefumigated soil, bacterial counts ranged from 10" to 104/g; inthe non fumigated soils, however, up to 10~-109 bacteria perg was found. It appears that microbial metabolites enhancethe desorption of oil components from the soil complex. Moredetailed investigations are needed to reveal the exact natureof these microbial biotransformations.

In practice, the clean-up procedure will involve, besidesirrigation and pumping of the groundwater, treatment of thepumped oil and water mixture. Therefore, it is of interest tofind that the biological desorption does not give rise to theformation of an oil-in-water emulsion. Indeed, since the oilcan be recuperated as a phase, the remaining effluent becomesmuch more easy to treat before discharge.

The results obtained indicate that the clean-up of subsurface horizons polluted with oil is possible by intensive irrigation of the soil with a nutrient solution. Comhinations of(NH"NO:I + peptone) and of (NH.INO:I + Et:IP04 ) are advisable for shallow and for deep soil horizons, respectively. Thetreatment should be started as soon as possible after the occurrence of the oil spill.

The soil percolate must be pumped up and treated appropriately. Tbe cleanup procedure will require at the least several months and at the best 10-20% of the oil adsorbed in thesoil will be recovered. The remainder is either firmly boundto the soil or biodegraded. Nevertheless, it continues to constitute a threat to the underlying water reserves.

As a whole, the cleaning in situ of subsurface soils saturatedwitb oil appears to be botb difficult and time consuming.Hence, precaution to prevent subsurface pollution must beadvocated as much as possible.

Literature Cited

(I) Concawe Secretariate, "Inland Oil ::ipill Clean-Up Manual",Report No. 4/75, Stichtillg COllcave, the Hague, 1974.

(2) Vallioocke, R, De Borger, R., VoeL".J. 1'., Verstraete, W., Ill/. J.c'nvirvll. Studies. 8,99-111 (1975).

(:l) La Hiviere, .J. W. M., Antunip von Leeuwenhorh. 21, 1-27(1955).

(4) Heisfield, A., Rosenherg, K, Gutnick, D., Appl. M;l'robiol.. 24,:16:1-8 (1972).

(!)) Zajic, ,J. E.. Supplissofl, B., Volesky, B., Environ. Sci. Techno!.,8,664-8 (1974).

(6) Dustalek, M., Spurny, M., ('esl<. Mil<robiol .. 2, :300-6 (1957).(7) Davies, .J. tt. "Petroleum Mitrohiology", Elsevier, Amsterdam,

1967.(8) Cassel, D. K., Krueger, T. H., Schroer, F. W., Nurum, E. H., Svil

Sri. SOl'. Am. Pro(' .. 38, :16-40 (1974).(9) Verstraete, W., Vanloocke, It. De Horger, R., Verlinde, A., Proc.

:lrd lnt. Biodegradation Symposium, pp 99-112, ,J. M. Sharpley andA. M. Kaplan, Eds., Applied Science Publishers Ltd., London,1976.

(10) Somers, J. A., Drok, J., IllS/. Gewlldheid"lel'h. TNO, Rapp. A.f,9 (1971).

Flel'eived [or reoiew November 2, /977. Al'('epled Augusl II, /978.'I'h/.'i work was supp()rled by the He/kian National R&lJ Prolfram unthe .h'nuirunment, Projed "GmundwQ{('r", Ministr," of Science Polie,}'ProJ.:ramminM·

Laser-Induced Fluorescence and Raman Scattering for Real Time Measurementof Suspended Particulate Matter

I. Allegrini'

C.N.R., Laboratorio sull'lnquinamento Atmosferico, Via Montorio Romano 36-00131, Rome, Italy

N.Omenetto

Istituto di Chimica Generale ed Inorganica, Universita di Pavia, Pavia, Italy

• Induced inelastic scattering such as Raman and fluorescence of artificially generated aerosols has been observed forexcitation with either continuous or pulsed lasers. Resultsindicate that fluorescence arising from most aerosols can degrade the signal-to-noise ratio to unpractical values whenmeasuring Raman signals. The analytical feasibility of thetechnique for the real time monitoring of suspended particlesis also discussed.

In Figure la, the line located at 1515 em-I, which appears tobe the most intense in a series of spectra of pure solid PAH,and thereby characteristic of these compounds, is still clearlyvisible, while the less intense lines at other wavenumbers areburied in the fluorescence background, which is due largelyto the aerosol.

Tar aerosols, excited by several lines in the blue-green region, show structure less, very intense fluorescence spectra,whose intensity decreases when irradiating at larger wavelengths.

'). (.m)

Figure 1. Raman spectrum of anthracene (uncorrected for instrumentalresponse)Excitation: argon ion laser, Aexc 488 nm; power, 500 mW; spectral bandwidth.1.5 nm; (a) aerosol; (b) solid

520' 500

J. (.m)

b)

a)

500520

540

540

560

560

580

580

intensity

Experimental Results and Discussiun

A few preliminary experiments were carried out in order todetect both the Raman and fluorescence spectra of artificiallygenerated aerosols. A few representative compounds wereselected, namely, tar, anthracene, and fluoranthene.

Continuous Wave Experiments. The experimental setupconsists of an argon ion laser (Spectra-Physics, Model 165-03),a double monochromator (Jobin-Yvon HDR-I), and a conventional photon counter (SSR, Models 1140A and B). Ahomemade aerosol generator was used to flow the selectedaerosol into a fluorescence cell equipped with Brewster windows. Typical conditions relevant to the measurements were:aerosol concentration in the cell, -10" cm-:l; mean particlesize, 0.4 /Lm; solvent, cyclohexane.

Figure la shows the spectrum obtained for anthraceneaerosols with the excitation set at 488 nm. For the sake ofcomparison, a Raman spectrum of solid anthracen~ is shownin Figure lb. As one can see from these figures, the Ramanlines are superimposed on a large fluorescence background.

The limitations posed by conventional sampling proceduresand subsequent analysis of particulate matter can be overcomeby the so-called in situ samplers, where the significant parameters of the particulate are measured without disturbingthe physicochemical equilibrium of the atmosphere. However,the most attractive approach to in situ measurements is givenby laser-based sensing techniques such as Raman and fluorescence scattering. A great deal of attention has been devotedto this field in recent years and the potential analytical feasibility of the various techniques has been evaluated by manyauthors (I-5).

The signal obtained when a powerful laser beam is directedtoward some polluted area is indeed difficult to evaluate because of the rather complex nature of the sampled region,whose unknown composition can give rise to several interference effects such as spectral overlapping of emissions.

A theoretical analysis of the signal-to-noise ratio which isexpected in a typical experimental setup shows that Ramanmeasurements can be severely limited by background fluorescence due to either gases or aerosols, though the use ofpulsed lasers and gated detection may reduce the relativeinterference according to the fluorescence lifetimes. Modulation of the laser beam and lock-in detection might extractthe delayed fluorescence signal whose attractiveness issomewhat reduced by its broad band distribution. Thischaracteristic would make the simultaneous analysis of severalconstituents rather difficult.

0013-936XI79/0913-0349$Ol.0010 © 1979 American Chemical Society Volume 13, Number 3. March 1979 349

30

celHlts.-.

Received lor review March 211, /978. Accepted September /4, /978.Finan.cial support from the European Communities Com mis.'iitm-Environmental Research Proxram (Rrussels) under Contracts1177-71-10 f;NV.1 and 068-71-1 ENV.I is gratelully acknowledged.

troscopy aerosols or gases mixed with fluorescing species ineither gaseous or particulate form. Such a considerationshould be taken into account in the field of remote sensing bylaser-induced Raman backscattering (6).

Pulsed Experiments. The fluorescence spectrum is excitedby a tunable dye laser pumped by a nitrogen laser at 337.1 nm(Molectron Models UV-400 and DL-200) and provided withfive KDP crystals for frequency doubling. Typical parametersof operation are 50-kW peak power, 5-ns pulse duration, and10-Hz repetition rate. The fluorescence signal is dispersed bya grating monochromator (Jarrel-Ash Model 82-463). Forpulse measurements a photodiode is used to trigger thecounting electronics, whose gate is set at a fixed value. In addition, for lifetime measurements, the counting process ispossible because of a variable gate given by boxcar integrator(PAR Model 162) externally triggered by the photodiode. Tbescanning facilities provided by the boxcar allow this gate tobe slowly swept along the decay curve of the fluorescence untilthe signal completely disappears. The aerosol is generated asin the CW experiments and flowed through an anodized aluminum cell, which is internally baffled to minimize scatteredlight.

The fluorescence spectra of tar and fluoranthene aerosolsare shown in Figure 2. Both spectra extend over a considerablybroad region in the visible spectrum. It is worth noting thattar does not fluoresce when excited at 260 nm, while fluoranthene fluorescence is very intense for UV irradiation. Fluoranthene fluorescence starts at about 400 nm; therefore itwould not be a problem when measuring Raman signals.

It is worth stressing that in a pulsed configuration a dramatic improvement of the signal-to-noise ratio for Ramanmeasurements can be achieved if the fluorescence radiativelifetimes of aerosols are much larger than the laser pulsewidths (7). Accurate measurements of such parameters arenow in progress.

In conclusion, both Raman and fluorescence spectra wereobtained in our experiments with CW and pulsed lasers forartificially generated aerosols. We would like to stress againthat we cannot claim any definitive conclusion yet on theanalytical feasibility of both techniques for in situ measurements of particulates. However, we feel these preliminaryresults are worthy of further investigation.

Literature Cited

(I) Wright, M. L., Krishnan, K. S., SRI Report EPA-R2-73-219,19?:!.

(2) Rosasco, G. ,I., Etz, E. S., Cassat, W. A., Appl. Specl"",c.. 29,396(1975).

(:1) Rosen, H., Novakov, '1'., Nature (London), 266,708 (1977).(4) Leonard, D. A., Technical Report AFAPL-TR-74-100, Oct

1974.(5) Stafford, R. G., Chang, R. K., Int. ConI'. on Environmental Sensing

and Assessment, Vo\. 2, IEEE, New York, N.Y. 1976.(6) Gelbwachs, .J., Birnbaum, M., Appl. Opt., 12,2442 (1973).(7) Van Duyne, R. P., ,Ieanmaire, D. L.. Shriver, D. F., Anal. Chem.,

46, (2), 213 (1974),

b)

.00

.00

1 (,,"')

500

500

000

000

/,I

II,,

I,I

'0

20

a)

The fluorescence intensity of anthracene aerosol is oneorder of magnitude larger than the Raman signal of pure N2at atmospheric pressure. Although the relative SIN ratio canbe increased by choosing a smaller spectral bandwidth, theinterference effect is still very high, thereby degrading the SINratio to unrealistic values when measuring by Raman spec-

').(nM)

Figure 2. Fluorescence spectrum of hydrocarbon aerosols (uncorrectedfor instrumental response)Excitation: N, pumped. frequency doubled. dye laser; spectral bandwith. 3.2 nm;(a) f1uoranthene aerosol, Aexc 260 nm; (b) tar aerosol, Aexc 421 nm

'0


Pressure Change Effects on Hypodermic NeedleCritical Orifice Air Flow Rates

Paul Urone*1 and Richard C. Ross

National Enforcement Investigations Center, Environmental Protection Agency, Federal Center, Denver, Colo. 80225

(5)

(4)

• Hypodermic needles are often used as critical orifices toprovide a known and constant air sampling flow rate. A studyof the effect of ambient air pressure changes on critical flowrates showed that comparative theoretical pressure changecalculations gave excessively low flow rates for large pressure(altitude) changes. As the ambient air pressure drops, thedischarge coefficients change, keeping critical flow rates highrelative to orifice plate theory but lower than ideal mass flowtheory. The discharge coefficient changes are not linear withpressure drop, but a linear approximation can be made withsmall error. Calculated critical flow rates with an average of2.2% and a maximum 5% error off the measured flow rateswere obtained by using the equation: Qa-max = Qc-max - C,~,

and specific adjustment constants (C,) ranging from 1.2 to0.125 mL min- l mmHg-l pressure change (tiP) for needlegage no.'s 18 to 27.

Hypodermic needles are frequently used as critical orificemeters for sampling ambient air. The critical air flow rate fora given needle is relatively easy to determine and remainsconstant provided that a vacuum of more than half of theupstream air pressure is maintained. Lodge et al. (1) studiedthe air flow rates of a wide range of needle gage numbers fromat least two principal manufacturers. They found that the flowrates for some 40 sets of 12 randomly selected Becton-Dickenson (BID) needles of a given gage number and length werereproducible with an average relative standard deviation of4% and an overall range of deviation of 1 to 9%. The length ofthe needles had only minor effect on the magnitude of the flowrates.

Because of the large altitude changes encountered by thefield personnel of the National Enforcement InvestigationsCenter, it was found desirable to measure the effects of relatively large ambient air pressure changes on the air flow rateof hypodermic needles.

Lodge's measurements were made at a mean barometricpressure of 630 Torr. 1'0 convert to air flow rates at 760 Torr,he suggested a 17% increment to be added to the 630 Torrmeasurements. Corn and Bell (2) had previously suggesteda change of 3% per in. (25.4 mm) Hg pressure change in theupstream air (P" Figure O. Corn and Bell also found a repeatability of ±3% among needles of the same gage number.

Equation 1 shows the theoretical relationship generallyaccepted as representing the effect of temperature and pressure on the critical flow rate (3):

= 0 388 C/JA,,P, (1)W max . VT

where W max = maximum mass flow rate of air at a critical orifice pressure ratio of 0.53 (g/s); Cn = discharge coefficient(dimensionless); A" = area of orifice opening (cm1); diameterof orifice should be SO.2 of tube or pipe diameter; P, = upstream pressure (g/cm1); and T = air temperature (K).

The ratio of the downstream pressure (P2) to the upstreampressure (P,) at which the critical flow rate is achieved is called

I Present address, Environmental Engineering Sciences, Universityof Florida, Gainesvilie, Fla. 32611.

the critical pressure ratio. Most studies report a criticalpressure ratio of 0.5 is satisfactory for critical flow. Huygen(4), in studying the use of glass capillaries, showed criticalorifice pressure ratios varying from 0.8 to 0.35 depending onthe shape of the capillary. In this study it was found that amore conservative pressure ratio for hypodermic needles was0.4 (60% vacuum; see Figure 2).

Equation 1 indicates that for a given needle the mass flowrate is proportional to the upstream, or inlet, pressure. Asimple mass to gas volume conversion (PV = nRT) leads oneto erroneously conclude that the ambient volumetric flow rate,Qa-ma" is independent of pressure. Hence, if a constant discharge coefficient is assumed (5):

Qa-max = k'V'i',. (2)

where Qa-max is the critical air flow rate at ambient, a, pressure, and k' is a collection of the constants for conversion ofEquation 1 to 2. However, the discharge coefficient, Cu, doeschange with pressure, so that Equation 1 becomes:

- CD,P"yTc (3)Wa~max - We-max COl'~ T

a

The subscripts "c" indicate the calibration mass flow rate,discharge coefficient, pressure, and temperature, respectively.Converting mass flow rates to volumetric flow rate:

=Q ~,\/T"Qa-max c-rnax C ,v TDc c

where CD: and CD: represent the combined conversion constants and pressure change effects for the discharge coefficients. When T" and T c are the same or within ±10 °C forsmall error:

Q -Q ~a-max - c-max CDc'

Theoretical quantification of Equation 5 is quite difficult.In the great majority of cases the discharge coefficient is determined experimentally. In these studies it was more appropriate to determine the rate of change of the dischargecoefficient with changes in the ambient air pressure.

Experimental

Figure 1 schematically shows the apparatus used to find thevariation of volumetric flow rate with pressure for a series of

Table I. Hypodermic Needle Dimensions, Slopes ofMaximum Critical Flow Rates vs. Pressure (Cs), andDischarge Coefficient Changes per mmHg PressureDrop (~CD)

gage length, J.d., orifice area, cs , .6.Co,no. mm mm mm' mL mmHg-1 mmHg-1

18 38 0.84 0.55 1.1 4.92 X 10-4

20 38 0.58 0.27 0.47 4.53

22 25 0.39 0.12 0.38 4.6924 19 0.29 0.067 0.34 2.42

27a 12.7 0.19 0.028 0.125 2.63

27b 12.7 0.19 0.028 0.125 2.63

27c 12.7 0.19 0.028 0.117 2.63

This article not subject to U.S. Copyright. Published 1979 American Chemical Society Volume 13, Number 3, March 1979 351

Table II. Measured and Calculated Ambient Maximum Critical Air Flow Rates (Oa-max) as Functions of Pressurecalcd L/mln

needle pressure, measured, slope 6cO orilicegauge Torr L/mln corrected a corrected b theory C

18 760 4.67

676 4.55 4.58 4.58 4.40626 4.47 4.52 4.52 4.24

526 4.46 4.41 4.34 3.89376 4.25 4.25 3.71 3.06

20 760 1.94700 1.91 1.92 1.92 1.87627 1.86 1.88 1.87 1.77577 1.84 1.86 1.84 1.70

527 1.82 1.84 179 1.62

477 1.80 1.81 1.74 1.54427 1.79 1.79 1.68 1.46

22 760 1.000

684 0.990 0.971 0.983 0.949633 0.975 0.951 0.967 0.913

533 0.926 0.913 0.926 0.837433 0.892 0.874 0.871 0.755383 0859 0.855 0.836 0.710

24 760 0.630

672 0.615 0.599 0.605 0.592637 0.590 0.587 0594 0.577587 0.581 0.570 0.577 0.554537 0.546 0.552 0.559 0.530487 0.530 0.535 0.537 0.504437 0.525 0.517 0517 0.478387 0.510 0.500 0.419 0.450

27 760 0.202676 0.195 0.192 0.195 0.191626 0.190 0.185 0.189 0.183526 0.180 0.173 0.178 0.168476 0.175 0167 0.172 0.160426 0.165 0.160 0.164 0.151376 0.156 0.154 0.156 0.142326 0.147 0.148 0.147 0.132

8 Oa-max = Qc-mall. - Cs.:lP; Qc-max taken at 760 Torr. bOa_max = Olheory (1 + ..1 Co ..1 p). c; Qtheory = Dc_max~; Qc-max taken at 760 Torr.

Figure 1. Schematic of apparatus used to measure air flow rates throughhypodermic needles used as critical orifices

hypodermic needle critical orifices. Upstream pressures (P"Figure 1) at laboratory (630 Torr) or lower pressures were keptconstant with precision valve 1, and the associated air flowrates were measured at increments of 50 Torr in the downstream pressure, P2• Each setting required careful balance offlow through both precision valves so that PI and P2 could bekept at the desired levels.

For flow rates less than 1 L per min, a soap bubble flow-

Results

Figure 2 illustrates plots of the flow rate data from a no. 27gage needle. The data are plotted as volumetric flow rates, Qa,at the upstream pressure, PI, vs. the downstream to upstreampressure ratio. The maximum, or critical, volumetric flowrates, Qa-max, were obtained from the leveling off portions ofeach curve based on a constant upstream, p" pressure.

Table I gives the needle characteristics and Table II presents maximum flow rate data obtained from plots similar toFigure 2 for the needles studied. The measured Qa-max datashow that the critical flow rates drop as the pressure (P 1, i.e.,P a, Figure 1) drops. Since Qa-max is not independent of thepressure drop, it follows that the discharge coefficient decreases with pressure drop. Plots of Qa-max vs. Pa were ap-

meter followed by a drying tube was used in place of the drytest meter. To obtain data at pressures greater than the laboratory air pressure, clean compressed air was used and controlled by adjusting the auxillary precision valve 3, whileprecision valve 1 was kept completely open. The experimentswere conducted at room temperature, which was relativelyconstant at 25 ± 2°C.

PrecisionValH 2

Precision HypodermicV~he 1 NeedleDry Test

Meter

AUI.PrecisionValve 3

Air ~ --4....--.. ,.-..,


'00".,

/

...P(f'~\ur~. mm Nt

20.

-0- Oltunul

--- QrdoCf 'h~~'J

SI,Of C,lcII,htll

• 6CIIl C,lc.l.hlll

2000

t!lOO

....1100

1600

~?:. 580

! '"

<.

...~ 20.

,,.

10'

,..

I,iterature Cited

(I) Lodge, ,J. 1'., .Jr., Pate, ,I. I:l., Ammons, Fl. K, Swanson, G. A., J.Air I'ollul. Conl",/ Asso('., 16,197 (1966),

(2) Corn, M.. Bell, W.. Ind. HV/i. Assoc J., 24, 502 (I96~).

(:0 Perry H. H.. Chilton, C. H., "Chemical Engineers' Handhook",5th ed, McCraw-Hili, New York, 197:1.

(4) Huygen, C., .J. Air /'o//lIl. Co"lrol As.,"(', , 20,67;; (970).(TI) ll.S. Environment.al Prot.ection A~ency.lnstitute for Air Pollution

Training, "Atmclspheric Sampling-: Calihration of Air Measuring:Instrument...... , U.S. (;overnment Printil1J{ Office, Washington, D.C.,p 4,1\)70.

(1;) Ower, K, Pankhurst, H. C" "The Me3'orement of Air Flow", p1:12, Pergamon Pres!o;. New York, 1966.

(7) Nelson, C. 0., "Controlled Test At.mospheres", p 45, Ann ArborScien<:e, Ann Arhor, Mich., 1972.

Figure 3. Comparison of measured and calculated maximum criticalorifice flow rates as a function of the upstream (i.e., ambient) pressure

/{efl'il.'f'c/ fur rC'uil'w tlum' 26, /97H. Accepted ()flober :ll, /978. TIJi..,wurl.' U'(l .... mad,. possible by an Inler~(Jvernm('nlal Personnel AdFelltm:ship ;.:ranled to P. Urone.

ment of calihrated critical flow rates for pressure differences,becomes, throu!(h Equation 6, a simple matter of (1) selectingthe proper slope correction factor for the size needle beingused (C, from fourth column, Table I); (2) multiplying thecorrection factor hy the pressure difference between thepressure at calihration and the actual pressure expressed inmmH!(; and (3) suhtracting, or adding for higher pressures,the product from the calibrated flow rate.

Flow rates corrected in this manner will not differ siJ(nificantly from actual flow rates. They may be used to obtain anapproximate flow rate or may be used directly with but littleerror.

(9)

(7)

(6)

(8)

'.2'.'...I.,••

C' __(,,,,,I,,,tl,,,l1'-,,,,c.:"__j, I> =

qlllt'n~llrt'd(.1/))

Thus, the ambient maximum air flow rate can be calculatedby the use of Equations 7 and 8 wbere:

Figure 2. Variation of volumetric flow rates through a no. 27 gage needlevs. downstream to upstream pressure ratios for various fixed upstream(P,) pressures

The results of such calculations are sbown in Tahle II and inFigure 3.

The data in Tahle II show that use of the slope correctionfactor (C,) gives pressure adjusted flow rates thai agree moreclosely with measured flow rates. Consequently, the adjust·

A somewhat more cumbersome method for calculatingmaximum flow rates involves determining the change in thedischarge coefficient per mmHg ('::'CI» hy takin!( the ratio ofthe theoretical orifice plate flow rate to tbe measured flow rateand dividing by the pressure chan!(e (j,/') (eq 8).

uo

..'"'"... m

• l6

'l6".,: ,..

where Q".max is the calibrated maximum flow rate, Cx is theslope correction factor per mmHg change in pressure, and '::'1'is the change in pressure hetween the calibrated and actualpressures, mmHg.

For comparison, Table II (final column) gives maximumflow rates calculated according to the theoretical plate orificeequation for pressure change effects (6, 7):

proximately linear (FiKure :n. The slopes diflered for differentKaJ(e numher needles hut were reproducihle for three needlesof the same J(aKe numher.

Table I also Kives the properties and slopes of maximumcritical flow rates vs. pressure of the needles studied. By usingthe slope of the lines it was possible to calculate the maximumflow rates with an average error of 2.2% and a maximum errorof 5% from the measured values (Table II). The equation usedfor these calculations was:


CORRESPONDENCE

SIR: The paper "Venturi Scrubber Performance Model"by Yung, Calvert, Barbarika, and Sparks [ES&T, 12,456-9(1978)1 represents a significant step forward in the on-goingeffort to produce better performance models for Venturiscrubbers. However, all recent models continue to suffer fromcertain fundamental defects.

The distribution of drop sizes in a gas-atomized spray isignored and instead a Sauter mean diameter is used to represent the spray. By means of sample calculations, Licht andRadhakrishnan (l) have shown that a significant differencein grade efficiency and in the overall penetration may be obtained when a drop size distribution is used rather than aSauter mean.

Unfortunately, the only data available for size distributionshave been determined on preformed sprays, that is, forpneumatic nozzles (see, e.g., Nukiyama and Tanasawa (2),Kim and Marshall (3), Licht (4». It is not only unrealistic toapply these to the gas-atomized sprays which are to be foundin Venturi scrubbers, but also it involves a transition to avastly different range of operating conditions than those whichwere used in the experimental work.

The only drop-size measurements on a full-scale prototypeVenturi are those of Boll (5), in which only Sauter mean sizeswere determined. Licht and Radhakrishnan (J) have shownthat these are low by as much as 50% of the values obtainedfrom the widely cited Nukiyama and Tanasawa equation, forcomparable gas velocity and liquid/gas flow ratio.

In fact, the question of which mean drop size to use to represent the spray in the collection performance model has neverbeen fully explored. There is no proof that the Sauter meanwould necessarily be the correct one. Instead, in the relatedcase of an equation to model the pressure drop across a Venturi where the Sauter mean is also usually recommended, thema;s mean drop size would seem to be far more logical, as hasbeen suggested by Yoshida et aJ. (6).

Research into these aspects of the Venturi model is ongoingat the University of Cincinnati.

Literature Cited

(1) Licht, W., Radhakrishnan, E., AlChE Symp. Ser., 74 (No. 175),28 (1978).


(2) Nukiyama, S., Tanasawa, Y., Nippon Kikai Gokkoi Rombunshu,4,86 (438); 5, 63 (1939).

(3) Kim, K. Y., Marshall, W. R, Jr., AIChE J., 17,575 (1971).(4) Licht, W., AlChE J., 20,595 (1974).(5) Boll, R H., et a!., J. Air Pul/ut. Control Assoc., 24,934 (1974).(6) Yoshida, T, et aI., Kagaku Kagalw, 3,232 (1965).

William LichtDepartment of Chemical and Nuclear EngineeringUniversity of CincinnatiCincinnati, Ohio 45221

SIR: Morishima and Yoshida (I) performed a mathematicalanalysis to determine the influence of liquid drop size distribution on the particle impaction and diffusion collection efficiency. The technique is based on calculating the averagecollection efficiency from the following equation:

Ii = J:~ ry f(dd) ddd

where ry is the collection efficiency of a single drop and f(dd)is the drop size distrihution function. Then instead of usingry and dd in the efficiency equations, Ii and dd are used. However, in carrying out this calculation, they concluded that thedifference between using 1/ and Ii is insignificant unless thedrop size distribution is quite wide. This technique is verycomplicated and one must use a numerical technique forsolving the equation. Our feeling is that given: (a) the absenceof reliable data on drop size distribution, (b) the complicatedtechnique for calculating penetration, and (c) an insignificantgain in most cases, the model developed by us is a step forwardand should be used as reported.

Literature Cited

(I) Morishima, N., Yoshida, T., Kagaku KO/iaku, 1114-9 (1967).

Seymour CalvertAir Pollution Technology, Inc.4901 Morena BoulevardSuite 402San Diego, Calif. 92117

00I3-936XI79/0913-0354$Ol.00/0 © 1979 American Chemical Society

INDUSTRY TRENDSVarian Associates (Palo Alto, CAl hasreceived two orders totaling more than$4 million, for analytical instruments,from the People's Republic of China.

Southern California Edison Co. expectsthat conservation programs it hasplanncd will save more than 3 billionkWh of electricity during 1979.

Autotrol Corp., the world's largestmaker of automatic controls for thewater softening industry, and of rotating biological contractors forwastewater treatment. is moving tonew quarters in Glendale, WI.

Radian Corp. (Austin, TX) has a$200000 contract from DOE to assessair pollution regulation impacts onthermal-enhanced oil recovery technology for recovering heavy oil bysteam injection.

Pacific Environmental Services, Inc.(PES, Santa Monica, CA) will be involved in writing and researchingregulations for a number of new sourcecategories, at its new facility in Durham, NC.

National Patent Del't'lopment Corp,( ew York, NY) will provide solarenergy collectors to the U.S. Bureau ofMines for the underground headquarters of the Bureau at Salt LakeCity, UT.

FluiDyne En2ineering Corp. (Minneapolis, MN) will design, construct. andstart up a facility to test candidate steelalloys for Iluidized-bed coal combustors at DOE's facility in Morgantown,WV.

The American Water Works Association will establish, this year, a WaterUtility Council, responsible for policies. programs, and activities affectingwa ter-oriented Iegisla tion / regulation.

Arthur G. McKee & Co. (Cleveland,OH) will provide technical/management services for a demonstrationprogram for using Iluidized-bed combustion to consume anthracite culm, atype of anthracite mining refuse.

A McDonald's restaurant in Kingston,Ont., Canada. is using solar energyfrom Grumman Sunstream collectorsto provide 9.4 million Btu/y for hotwater for the kitchen and rest rooms.

Southern California Edison andChevron Resources Co. have an

agreement by which the utility willpurchase geothermal brine for a commercial geothermal power plant inCalifornia's Imperial Valley.

A subsidiary of Cherne Industries,Inc.(Minneapolis, M ) received an orderfor a sewer inspection unit from AbuDhabi, United Arab Emirates. Theunit is equipped with closed-circuittelevision.

Norton Co. (Worcester, MA) has aDept. of Defense (DOD) order for 2.1million pairs of gloves that protectagainst chemicals. The gloves will bemanufactured in Charleston, Sc.

Solarex Corp. (Rockvillc, MD) wasthc company that provided Typc9200J Unipanel® solar panels and abattery bank for thc solar electric installation of the Indian village ofSchuchuli, AZ (ES& T. February1979, p 140).

United Air Specialists, Inc. (Cincinnati, OH) will providc five Smog HogAir Pollution Control Systems, worthover $80 ODD, to TR W Inc., to controlaluminum forging smoke at TRW'sfacility in Cleveland, OH.

The M02ul Division of the DexterCorp. (Chagrin Falls, OH) has againreceived the John C. Vaaler Award,sponsorcd by Chemical Processingmagazine, for low molybdenumphosphorus inhibitors for cooling watersystems. They comply with government toxic rules.

The National Coal Association toldLS& T that future Coal Conferenceand Expositions, which the associationhas sponsored in the past, will now beunder the auspices of Coal Age magazine. a McGraw-Hili publication established in 1911.

Phillips Petroleum Co. (Bartlesville,OK) has sold a large oil re-refiningprocess (PROP) plant to Mohawk OilCo., Ltd. (Canada). It will reprocess 5million gpy of waste lubricating oil tomore than 4 million gpy of a productcomparable to high-quality "virgin"oil.

General Public Utilities Corp. (Parsippany, NJ) announced that its thirdnuclear generating station has added900 MW to its system-wide nuclearcapability, and brought nuclear powerto 40% of the power GPU produces.The new facility is near Harrisburg,PA.

Lobsenz-Stevens Inc. (New York, NY)has been retained as national publicrelations counsel to the American Society of Civil Engineers.

Apollo Chemical Corp., Whippany, NJ(ES& T, December 1978, p 1362), hasbeen cited in Science Year, The WorldBook Science Manual for its "outstanding contribution to coal utilization," because ofa system which prevents frozen coal problems from occurring.

Stanley Consultants, Inc. (Muscatine,IA) will design a new headquarterscomplex, at Grafton, IL, for a divisionof the U.S. Fish and Wildlife Service.

EIlI'ironmental Elements Corp. (Baltimore, MD) has recently installed apilot baghouse collector at BaltimoreGas and Electric Co.'s Wagner StationUnit No.3. It is to tryout 12-in. diameter bags.

J.T. Baker Chemical Co. (Phillipsburg,NJ) has expanded its line of productsfor chemical spill control in truckingterminals. warehouses, stockrooms,and similar locations.

New England Research, Inc.(Worcester, MA) has a $50 000 contract to prepare a Regulation Informalion Program for shippers andtransferers of hazardous waste materials, under the Resource Conservationand Recovery Act of 1976.

The Heil Co. (Milwaukee, WI) saysthat a Madison, WI solid wasteshredding plant, which Heil is buildingunder contract, represents "vastlyimproved" processing. The shredder'srefuse-derived fuels will be uscd byMadison Gas and Electric Power.


Wyle Laboratories (EI Segundo, CA)will do research on noise associatedwith underground coal mining operations for the U.S. Bureau of Mines.The contract is worth more than$500000.

Flintrol, Inc. (Jonesboro, AR), theworld's largest manufacturer of totalelectric pollution control systems andequipment, will add 22000 ft 2 to itspresent 35 000 ft 2 of manufacturing,engineering, warehouse, and officespace.

Dames & Moore Iberia, S.A. (Madrid,Spain) will design an open-pit mine fora large lignite deposit at La Coruna,for Empresa Nacional de Electricidad,S.A., the Spanish national electriccompany. The lignite will fuel a1400-MW power plant at Puentes deGarcia Rodriguez.

Badger Meter, Inc. (Tulsa, OK) hasappointed Pratt Engineering Co. torepresent Badger's line or environmental-related products in southernTexas, and parts of Louisiana.

Environmental Elements Corp. willsupply air filtration, and silencingequipment, worth $250000, toKvaerner Brug A/S (Oslo, Norway),for the first large gas turbine powergeneration package in that country.

CVI Corp. (Columbus, OH) has a$13.6 million contract from LawrenceLivermore Laboratory to design, fabricate, install, and test a FusionChamber System. The system mustachieve temperatures of -452 0 F.

Engelhard Industries (Iselin, NJ) willsupply Toyota with three-way conversion catalysts for NO" HC, andCO control for the 1979-1981 carmodel years.

,,~ .. ,

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The United States Testing Co., Inc.(Hoboken, NJ) has been certified as awater supply testing laboratory by theState of New Jersey Dept. of Environmental Protection. U.S. Testingwas founded in 1880.

Bahco Systems, Inc. (Atlanta, GA) hasacquired Air Quality Testing and Design Co., engineers for turn-key systems, air pollution, and nuclear testingservice and manufacturing. Bahco is asubsidiary of AB Bahco (Sweden).

Research-Cottrell (Bound Brook, NJ)announced that fiscal 1978 was itsmost profitable in its 66 years of existence, and that it is establishing newproduct positions with use of fabricfilters on utility boilers.

The Energetics Science division ofBecton Dickinson and Co., will supplymultipoint carbon monoxide (CO)monitoring systems for San FranciscoAirport's 7000-car parking garage,and other facilities in the area.

UOP Inc. has a $2.8 million contractfrom Resources Conservation Co., fordesign, construction, and start-up of a2.3 million-gpd reverse osmosis systemfor wastewater reclamation at SanJuan Power Station near Farmington,NM.

Tetra Tech Inc. has been recognized byDOD for superior performance insafeguarding classified information indoing U.S. government work.

Acoustic Technology, Inc., a part ofAcoustic Technology Ltd. of England,has opened an office in Houston, TXto help customers meet noise regulations, and to solve noise/vibrationproblems.

Fibrous aerosol monitorThe manufacturer claims that theinstrument provides real-time monitoring of airborne fibers, in fibers/cc,even in the presence of large concentrations of non fibrous particles. GCAEnvironmental Instruments 101

Gas-phase titration calibratorThe unit offers field and laboratorycalibration of analyzers of oxides ofnitrogen, sulfur dioxide and ozone.Single- and multi-point calibration,and zero and span calibration areprovided. Concentration stability forNO/NOzand SOz is ±0.5%/24 hand± 1.0%/24 h for 0 3. Columbia Scientific Industries 102

HC/CO/COz exhaust gas analyzerThe manufacturer claims that this isthe first commercial, portable standardmonitoring system for hydrocarbons,carbon monoxide and carbon dioxidefrom automobile engines, stationaryturbines, furnaces and incineratoranalyzers. Beckman Instruments 103

Combustible gas/Oz monitorThis personal, portable monitor can behand carried or worn to test the air inmanholes, tanks, tunnels and otherenclosed areas for combustible gas andoxygen deficiency. Methane can bemonitored over a 0-5% range; theoxygen meter scale is 0-25%. Energetics Science 104

Multipoint temperature monitorThe monitor simultaneously displaysup to 60 thermocouple outputs on alarge screen CRT display with 0.2 °Cresolution for type K thermocouples.Kazmierowicz Instrument 105

PRODUCTS

Low level gas detectorThis instrument can detect and identify compounds below 0.001% in seconds. It finds application in ethyleneoxide production, vinyl chloride processing and steel manufacturing, forexample. CVC Products 106

Flow monitorThis ultrasonic flow monitor is·equipped with 32 preprogrammed flowcurves. The unit measures the rate offlow and total flow through any type offlume, pipe, weir or open channel.Environmental Measurement Systems

107Toxic gas alarm systemA portable unit, the system will continuously and simultaneously warnworkers of combustible, oxygen deficient and harmful toxic gases. Dynamat~n 1~

V-notch weirThe device is designed for measuringlow-flow conditions. The weirs areavailable in sizes for 8-in., 10-in., 12in., or 15-in. pipes. A bubbler attachment for remote readout is available.NB Instruments. 109

Sulfide analyzerThe unit permits direct sulfide measurement. The detection limit is lessthan I ppb to 10000 ppm sulfide.Calibration can be performed at anypoint within the measuring range.Orion Research 110

HPLC columnsThe prepackaged columns for highperformance liquid chromatographyhave efficiencies typically greater than50000 plates/m, excellent peak shapesand extended lifetimes, claims themanufacturer. Four column types areavailable; each column is supplied witha test chromatogram and test sample.Altex Scientific III

Combination pH electrodeThe unbreakable flat surface combination pH electrode features a built-insealed, gel-filled reference electrode.Four reference junctions are locatedaround the pH-responsive flat surface.With these junction locations, measurements can be made with minimum-size samples. Sensorex 112

UV disinfection unitsDesigned to treat secondary sewageeffluent, these disinfection units willmeet proposed fecal coliform limits of100 Col/ 100 mL. Pure Water Systems

113

Oscillographic recorderThe multipurpose recorders use athermal, inkless writing system toproduce continuous rectilinear traces.Recorders are available with 2, 4, 6 or8 channels and can be operated at 21different speeds ranging from I mm/hto 100 mm/s. It can be equipped forremote operation. MFE Corp. 114

Oxidant monitorThe amperometric monitor is designedfor use in chemical and metal processing industries and in water purification plants. The instrument is factory calibrated for chlorine measurement, but can be used for measuringozone, bromine, fluorine and iodine inconcentrations up to 5 ppm volume inair. Mast Development 115

Nitric oxide analyzerThe unit is designed to measure accurately and quickly the nitric oxideconcentrations in the tailgases emittedby catalytic converters. ColumbiaScientific Industries 116

Electrodialysis systemThe system, designed for the regeneration of chromium oxidizing solutions,finds application in plastic etches,brass and copper bright dips andpickling solutions, and solutions usedfor oxidizing organic chemicals. It willaccommodate a wide variety of concentrations and temperatures. AMJChemical 117


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Multipoint oxygen monitorThe unit can monitor up to eight individual in situ oxygen analyzers simultaneously. The monitor will displayone selected channel continuously, orit will automatically display the statusof each channel and its average at anadjustable scan rate of 0.5-1 0 s/point.Dynatron 118

AeratorThe aeration equipment finds application in municipal or industrialwastewater treatment systems. Thebasic unit is an aspirator pump thatinjects oxygen below the wastewatersurface to increase the oxygen concentration of the water: and dissipatessurface solids and eliminates noxiousodors. Aeration Industries 119

Condensa tion nucleus counterThis sensitive particle counter incorporates a single-particle countingtechnique to measure the concentration range from 0.01 particle/cm3 to1000 particles/em] Applications include air pollution research and inhalation studies. TSI Inc. 120

Mobile sludge processorThe unit converts municipal and/orindustrial sludges into "ecologicallyacceptable friable earthlike materials,"claims the manufacturer. EcologyProducts 121

Dust collectorThere is easy access to the fabric filterelements in this dust collector. The unitis adaptable for applications with airvolumes from 400 to more than100000 ft 3/min. The basic cell contains about 105 ft 2 of fabric filter.DCE Yokes 122

Conductivity probeThe probe measures total dissolvedsolids in solutions; it can be used directly with a pH/millivolt meter. Theconductivity range is 0-1000 microohms in five full-scale ranges.Lazar Research Laboratories 123

IR spectrometerThe manufacturer claims that the instrument offers the advantages ofFourier transform methods-sensitivity, accuracy and speed-at a pricecomparable to dispersive spectrometers. Nicolet Instrument 124

Insulated containersThese polystyrene foam plastic mailingcontainers, with capacities from 2 ozto 200 Ib, are designed to carry environmental samples, among otherthings. They are light weight and reusable. Polyfoam Packers 125

Activated sludge monitorThe instruments provide two piecesof information: biological-respirationrates or oxygen demand, and physical-settling rates and settled volume.These are useful in determining thereturn sludge rate and aeration, forexample. Tech-Line Instruments

126

Strip-chart recorderThis series model accepts digital datadirectly from a computer or an instrument bus. It converts the datainput into a smooth analog curve at awriting rate of75 cm/s. Paper advanceand pen lift are under digital control.Pedersen Instruments 127

Faucet filterThe compact water filter snaps ontoany faucet; water passes through carbon particles to emerge from the unit"clean" and "good-tasting." KeystoneFilter/Met-Pro 128

Sludge pH electrodeThe flat surface pH electrode is designed for rapid, accurate measurements by touching the electrode to thesemisolid surface of the sludge. Theelectrode may be used with any standard pH meter, and operates reliablyat temperatures of -5 to 80°C. Corning Glass Works 129

CO detectorThis disk of palladium chloride, redtan in color, darkens to shades ofbrown in the presence of carbon monoxide at concentrations greater than 30ppm. The disk gives accurate readingsfor one month. A color-guide card indicates the color changes for variouslevels of the gas. Soiltest 130

Electronic recording balanceFeatures include high-accuracy electronic tare, pushbutton recorder rangesfrom 10 fJ.g to 1000 mg full scale, capacities to 2.5 g, and sensitivities downto 0.1 fJ.g. The instrument consists of aweighing unit and a separate controlunit. Cahn Instruments 131

Sewage pumpThis electric, submersible pump findsapplication in sewage and drainagesituations. The manufacturer claimsthat it offers efficiency and requireslow maintenance. Pumpar 132

Ultrasonic spray nozzleThis model will atomize nows in excessof 7 gpm. The manufacturer claimsthat it delivers the smallest dropletsizes available at present; it can delivermean particle sizes in the 1-5 J1. range.These droplets are suitable for treatment of contaminated gas upstream ofair pollution control equipment. HeatSystems-Ultrasonics 133

Three-stage filter unitHung from the ceiling, this unit cleanshazardous particulates from indoor airin all types of industrial plants. It isespecially effective against asbestosfibers, the manufacturer claims.Airomax 134

Electronic balanceThis top-loading balance offers theuser two readability ranges-a 400 gfine range that is movable along a 4000g coarse range. The fine range isreadable to 0.0 I g; the coarse range to

0.1 g. Typical stabilization time isabout 2 s. Mettler 135

Heated bag cleaning dust collectorThe dust collector uses process-heatedatmospheric air for bag cleaning:which helps to prevent moisture fromblinding and plugging filter bags inprocess-drying applications. W. W. SlyManufacturing 136

Dichotomous impactorClassifies inhalable particles into twosize fractions: coarse, 15-2.5 J1.; fine,2.5 J1. and smaller. Particles are deposited directly on a filter media.Features include a timer, weatherproofenclosures, and separate impactor andcontrol packages. Environmental Research 137

Computing software packageThe program, Modeling and Reporting Software Package, is availablefor a one-time use fee of $2000, andcan be used with the company's desktop computer. It is designed, so thecompany says, "to streamline businessanalysis and graphic reporting in theenvironmental control industry."Tektronix 138

Calcium monitorThis monitor measures calcium overthe concentration range 0.001 ppm to100000 ppm in water systems. Measurement precision is within ± I()O,6 andresponse time to a concentrationchange is within one minute. OrionResearch 139

PID detector for GCThis high temperature photoionizationdetector for gas chromatography hasan operating limit of 2 picograms to 30micrograms. Its high temperature (upto 300°C) analysis permits pesticideanalyses, including the chlorinated,phosphorous and sulfur-based pesticides at lower levels than previoustechniques; it is a nondestructivemethod. HN U Systems 140

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Portable 502analyzerThe light-weight unit is self-calibrating, and responds in seconds to give acompletely integrated answer in 3 minon a direct-reading dual-scale meter.The unit's range is 0.0.5 ppm full scale,with up to 0-20 ppm in 6 steps. CEAInstruments 142

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BiocideThe electrolytic hypochlorinator provides the biocidal action of chlorinationwithout the problems of transportationand storage of hazardous chlorine orliquid sodium hypochlorite. It findsapplication in oil rigs' seawater systems, and sanitary and sewage lines.Engelhard Industries 143

Pocket-size pH meterFeatures include accuracy and readability to 0.06 pH units over a full 0-14pH range. The "transistorized" unit ishoused in nonbreakable, high-impactplastic case. Serfilco 144

CO or H2S monitor/alarmThe instrument's meter displays concentrations over a range 0-500 ppmfor carbon monoxide and 0-250 ppmfor hydrogen sulfide. A visual alarm oroptional audible alarm warns when asafe gas concentration is exceeded.Energetics Science 145

S02/S0J scrubbing systemsThese compact systems arc designedfor process gas streams and smallsteam generators burning coal or oil.The horizontal units are shipped prewired and prepiped. The systems use a

sodium-based absorption solution thatcan usc caustic soda or soda ash asmakeup. The system can be combinedwith particulate matter removal systems. Andersen 2000 146

Hazardous disposal unitThe unit for processing and stabilization of a wide range of hazardous industrial wastes is mobile, and can turnthese toxic materials into environmentally acceptable products at theplant site, the manuf:.lcturer says. IUConversion Systems 147

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Catalysts for the Controlof Automotive Pollutants


LITERATURE

Water softening. Brochure No. 3.137describes packaged units for economical, efficient water softening. Handles8-600 gpm of water. Single, double, ortriple modules, self-contained. CraneCo. 151

Calcium measurements. Informationis available concerning the Model 1250calcium monitor. Range 0.001100000 ppm of calcium. Orion Research 152

S02 analyzer. Brochure with price listtells about Model U2-DS portable S02analyzer for ambient-level measurements. Very sensitive. Weighs Icss than5 lb. Gives direct-reading answer in 3min. CEA Instruments, Inc. 153

Gas chromatography. Manual describes applications of photoionizationdetector in gas chromatographicanalysis. Hydrocarbon, and manyother determinations. HNU Systems,Inc. 154

Oil measurement. "Oil in the Environment" tells how to use fluorometersto measure both emulsified and dissolved oil in water, locate undersea oilleaks and seepage, perform baselinestudies, and the like. Turner Designs

155

Thermal analysis. 990 TA Brochuregives particulars about thermal analysis technology. Du Pont 156

Solids separation. Bulletin describesSOM-A-PRESSoo

, to separate solidsfrom water, and vice versa, at industrial, municipal, and commercial facilities. Will dewater 700-2000 lb/h ofslurry in 20 ft2, maximum, of floorspace. Somat Corp. 157

Laboratory supplies. January 1979catalog of laboratory supplies is nowavailable, and describes how easy it isto order. Interex Corp. 158

Biochemical research. Catalog BR 360lists equipment, such as pH meters,titrators, and other supplies forchemical and biochemical work. Otheraccessories are also listed. BrinkmannInstruments Inc. 159

Filters. Revised Bulletin KF-l detailsline of plumbed water filters and replacement cartridges. Longer' life,higher flow rate, less pressure loss.Keystone Filter Division, Met-ProCorp. 160

Oxygenation. Brochure describes innovative way of injecting oxygen belowwastewater surface. Solids are dissipated, odors are "killed," and energyrequirements are cut by up to 50%.Aeration Industries, Inc. 161

Clarifier design. Bulletin 302 describese1arifier design with no wetted movingparts. Traveling bridge 7-120 ft, andmore. Company tells about hydraulically superior performance, and improved design. Aqua-Aerobic Systems,Inc. 162

Dust collection. Product literaturedescribes dust collection system, usingTorit TD cartridge filtration. Canoperate up to 200 in. H20 vacuum,and prevent violation of EPA/OSHAstandards. Independent EquipmentCorp. 163

Carbon analyzer. Bulletin 4197 describes analyzer for organic carbon inwastewater, potable water, andchemical processes. Total organiccarbon is analyzed. EPA-approvedtechnique. Beckman Instruments,Inc. 164

Digester cleaning. Flyer sheet offerscontracting services for digesters thathave become sluggish or inoperable.Design efficiency is restored. Ace PipeCleaning Inc. 165

Tank/pump stations. Catalog lists tankand pump stations, liquid level controls, control panels, and remote alarmpackages. All plastic, for use withcorrosive materials. The Jobar Corp.

166

Need more information about anyitems? Ifso, just circle the appropriatenumhers on one of the reader servicecards hound into the hack ofthis issueand mail in the card. No stamp isnecessary.

Oxygen monitor. Brochure describesYSI Model 56 Dissolved OxygenMonitor. Fully self-contained andportable. Two-channel recorder; rechargeable power pack; works unattended up to 10 days. Yellow SpringsInstrument Co., Inc. 167

Mixing/aeration. Bulletin 207 givesyou one source for all mixing andaeration needs for water and wastewater treatment, and lists many applications. Kenics Corp. 168

Toxic gas detection. Data Sheet 0801-01 describes Monitaire'· Sampler,Model TD, to detect gases such ashydrogen cyanide, S02, ozone, hydrogen sulfide, mercury vapor, andother toxic gases. Mine Safety Appliances Co. 169

Oil mist removal. Brochure tells how toremove oil mist from air. A number ofremovers are listed. Balston, Inc. 170

Power plant assessment. Brochuredescribes company's capabilities andexpert personnel for complete environmental assessments involvingpower plants, in its new division.WAPORA, Inc. 171

Spray drying. Brochure describes spraydrying technology all the way fromdesign to field service, for any givenneed. Stork-Bowen 172

Gas scrubbing. Bulletin describes systems for particulate and S02 removalfrom fossil fuel burning, S02 manufacture, smelting, acid plants, andother applications. Koch EngineeringCo., Inc. 173

Liquid chromatography. Bulletin No.124 tells about high performance liquid chromatography (HPLC) and itsuses for pesticide, protein, and otheranalyses. Theory is explained. Whatman Inc. 174

FGD operation. Bulletin TB 206 tellshow a flue gas desulfurization (FGD)system operates in Texas at a lignitefuel-powered generating station. Muchdesign data are given. Research-Cottrell 175


Sulfur analyzer. Bulletin No. 475 tellsabout a bench-top unit that determinesavailable sulfur concentrations0.005-100% in all fossil fuels, within2-3 min, with precision. Fisher Scientific Co. 176

Dosimetry. Catalog 791 lists a full lineof radiation dosimeters from the largest producer of such equipment in theworld. Dosimeter Corp. of America

177

Air pollution control. Folder detailscomprehensive air pollution controlsystem now in operation at Springfield(MO) City Utilities. S02/particulateremoval and monitoring are discussed.UOP Inc. 178

Dust control. Basic methods-unitcollectors and central systems-aredescribed and compared in a new literature item. Engineering, flexibility,and other topics are discussed. DCEVokes Inc. 179

Gas detection. Condensed Catalog 101lists all major gas detection products.Lumidor Safety Products 180

Environmental "pubs." "Environmental Publications 1979" lists manybooks on pollution control, solid waste,recycling, and energy. TechnomicPublishing Co. 181

Water treatment. Bulletin No. 4921 Ddescribes latest standard "packagetype" water treatment equipment for10-900 gpm. Ancillary equipment canbe added, as necessary. Permutit 182

CO indicator. Data sheet 08-00-22describes portable carbon monoxide(CO) indicators for workplaces, busterminals, sewers, vaults, garages, andother applications. Rechargeable2.4-V NiCad batteries. Mine SafetyAppliances Co. 183

Flow meter. Bulletin GS describessolid-state now meter useful for 849-in. sewer pipes. Used in openchannels. Tracking accuracy of 0.0 I ft.Installable in less than 15 min. N BInstruments, Inc. 184

Liquid chromatography. Order No.L-567 lists liquid chromatographyapplications, especially with respect toenvironmental analysis. PerkinElmer 185

Sewer cleaning. "810 brochure" tellshow water pump can build up to 2000psi water pressure for storm/sewer linecleanout. Has 9 yd 3 debris tank, but


can be mounted on single-axle truck.Myers-Sherman Co. 186

Sludge collection. Bulletin 316-65Rdescribes non-metallic, non-corrodable, lightweight chains for sewagecollection-a wastewater industry"first" (ES&T. December 1976, p1198). Envirex 187

Vessel lining. "Spotlight Kynar" listsnew forms and uses for this highlycorrosion-resistant plastic. Pennwalt 188

Direct filtration. Brochure tells how adirect filtration system can deliverhigh-clarity water for smaIl-community water supplies, with minimumoperator attention. Culligan USA

189

Water/wastewater analysis. Catalog12A lists portable instruments, processanalyzers, and test kits, as well as newproducts for water/wastewater analysis, cooling waters, and other. HachChemical Co. 190

Radiation doses. Catalog lists wholelines of dosimeters to measure radiation in many different places. Dosimeter Corp. of America 191

Organics monitor. Technical data areavailable concerning the "M-82" Organic Contamination Monitor. It isdesigned for low-level detection of organics breakthrough in high-puritywaters. lonics, Inc. 192

Rotary pumps. Catalog 10.0 lists an allplastic, sealless, rotary pump to handleacids, caustics, corrosives, hydrocarbons, and hazardous or abrasive liquidsand gases. Vanton Pump and Equipment Corp. 193

Geothermal Energy. "Effects of Geothcrmal Energy Development on Fishand Wildlife." FWS/OBS-76/20.6.Fish and Wildlife Scrvicc, NationalPower Plant Tcam, 2929 PlymouthRoad, Room 206, Ann Arbor, M I48105 (write direct).

"OTA Priorities 1979." Lists technological priorities, as drawn up by theOffice of Technology Assessment(OTA). Office of Technology Assessment, Washington, DC 20510 (writedirect).

North Sea Oil. "The Shetland Experience, concerning North Sea Oil," isa free-loan film. Modern TalkingPicture Service, Inc., 2323 ew HydePark Road, ew Hyde Park, Y11042 (write direct).

Land use. "Land Use Issues." CED79-15. The many concerns are discussed. United States General Accounting Office, Washington, DC20548 (write direct).

"Ecology." 1977-78 annual report.Institute of Ecology, University ofGeorgia, Athens, GA 30602 (writedirect).

Pulp/paper industry. Special Reporto. 78-04 surveys pulp/paper pollu

tion control expenditures over 1977.National Council of the Paper Industry for Air and Stream Improvement,Inc., 260 Madison Ave., ew York,NY 10016. (write direct).

GAC. "Black makes white" and "Purification of gases and liquids ..." tellhow granular activated carbon (GAC)can be used to clean many media.Norit N.V., 3800 AC Amersfoort,Postbus 105, Nijverheidsweg-Noord72, Thc Netherlands (write direct).

Asbestos. Assessment of asbestoscontamination put out by SyracuseResearch Corp., under EPA contract.EPA 560/6-78-005. Office of ToxicSubstances, EPA, Washington, DC20460 (write direct).

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BOOKS

Solar Energy in America. William D.Metz, Allen L. Hammond. AmericanAssociation for the Advancement ofScience, Dept. QB, 1515 Massachusetts Ave., N.W., Washington, DC20005. $8.50, paper; $18.50, casebound.

This book looks at the '?arieties oftechnology that are considered solar,and discusses passive heating, wind,biomass, rooftop collectors, and industrial uscs. Electric power applications, such as ocean thermal, photovoltaics, and the "pOwer tower" areaIso covered.

Alternative Energy Sources. T. NejatVeziroglu, Editor-in-Chief. II vols.Hemisphere Publishing Corp., 1025Vcrmont Ave., N.W., Washington,DC 20005. 1978. $495 plus taxes,postage, handling.

This set covers just about all that isknown concerning alternative energysources. These include solar (all aspects), nuclear/breeder, fusion, geothermal, hydrocarbon conversion,hydrogen, economics and policy, anddelivery and conservation. There is agreat deal of "how-to" information.Also, uses worldwide are covered.

Growth & Clean Air. J. C. Turner,Angelo Fosco. 100 pages. NationalEnvironmental Development Association, o. 3 National Press Building,Washington, DC 20045. 1978. $4.

The authors of this book are laborunion presidents. They advocate cleanair and economic growth as twin goalsfor labor, and balance between environmental, economic and energyneeds. Problems of industry locating innonattainment, and prevention of significant deterioration areas are discussed in simple terms.

Environmental Disputes. Cassette.Publications Department, AmericanArbitration Association, 140 West51 st St., New York, NY 10020. 1978.$15 ($12.50 for AAA contributingmembers).

The cassette will cover revolution ofvalue conOicts, selection/training ofthird-party intervenors, environmentalmediation techniques, and politicalrealities. Speakers include RussellTrain, John Busterud, and many otherdistinguished personalities.


Safe Drinking Water: Current andFuture Problems. Clifford S. Russell,Ed. xix + 641 pages. The Johns Hopkins University Press, Baltimore, MD21218.1978. $12, paper.

This Resources for the Future(Washington, DC) book covers asymposium on the subject, held atWashington. It looks into epidemiology, toxics, meeting standards, financing, jurisdictional issues, andother matters related to many aspectsof safe drinking water.

Disinfection of Wastewater and Waterfor Reuse. George Clifford White. 379pages. Van Nostrand Reinhold, 135West 50th St., New York, NY 10020.1978. $24.50.

The most modern methods of disinfecting wastewater and water forreuse are set forth in this handbook. Itprovides up-to-date design and operation techniques for all disinfectants,chemical usage, supply systems, andequipment. Innovations in ozone useare also featured.

Developments in Aerosol Science.David T. Shaw, Ed. 328 pages.Wiley-I nterscience, Box 092, Somerset, NJ 08873. 1978. $24.50, hardcover.

This volume provides a comprehensive coverage of aerosols in theirmany aspects, and goes exhaustivelyinto their physics.

Manual for the Use of SBA's PollutionControl Financing Guarantees. JamesH. McCall, Robert P. Feyer. 80 pages.Council of Pollution Control Financing Agencies, 5820 Wilshire Blvd ..Suite 500, Los Angeles, CA 90036.1979. $15 (quantity discounts available).

This manual tells how a small business might, for example, arrange for a100% guarantee by the U.S. SmallBusiness Administration (SBA) forpollution control financing. This financing can be for up to 30 years, frombanks, investment bankers, state/localagencies, and other sources. Financialassistance is aimed at helping smallbusinesses to comply with environmental regulations. The Council willbe holding workshops in the future; formore information, telephone (213)937-5518.

Energy Utilization and EnvironmentalHealth: Methods for Prediction andEvaluation of Impact on HumanHealth. Richard A. Wadden, Ed. xiv+ 200 pages. John Wiley & Sons, Inc.,605 Third Ave., New York, NY10016. 1978. $23.95, hard cover.

In the past, there has been little attention accorded to health questionswhen site planning for energy production facilities of pollution controlstrategies was done. This book confronts these health issues, and explainsand demonstrates evaluation methodswhich can be used to incorporatepublic health considerations into thisplanning process. Environmental impacts, biological effects, and real-lifeapplications are among the main topicsconsidered.

Scientific Problems of Coal Utilization: Proceedings of a Conference.Bernard R. Cooper, Ed. xi + 409pages. National Technical InformationService, U.S. Dept. of Commerce,Springfield, Va. 22161. 1978. $9,paper.

What are environmental implications of increased coal utilization')What are the ramifications of directcombustion, gasification, and liquefaction? These topics are dealt with byconference papers given at Morgantown, WV (West Virginia University)in May 1977, by 17 invited speakersand four panels.

Environmental Impact Analysis:Emerging Issues in Planning. RavinderK. Jain, Bruce L. Hutchings, Eds. xii+ 241 pages. University of IllinoisPress, 54 E. Gregory Dr., Champaign,IL 61820.1978. $12, hard cover.

This collection of conference paperscovers agency decision processes ofimpact assessment. The conferencewas held in May 1977 at the University of Illinois.

Polycyclic Hydrocarbons and Cancer.Vol. I: Em'ironment, Chemistry, andMetabolism. Harry V. Gelboin. PaulO. P. Ts'o, Eds. xi + 408 pages. Acadcmic Prcss Inc.. III Fifth Ave., NewYork, NY 10003. 1978. $37.50. hardcover.

Many are the sources of polycyclichyd roca rbons- pet roleu m, refuseburning, heat and power generation,and others that are well known. Thepapers in the book consider thesecompounds as representing a seriousthreat to health and quality of life.They discuss such substances as benzopyrene, tobacco, nitrosamines, andothers, and their sources. and explainthe mechanism of harming the body.Many acknowledge experts in the fieldcontributed the book's papers.

Protecting the Golden Shore: Lessonsfrom the California Coastal Commission. Robert G. Healy, Ed. xiii + 257pages. Conservation Foundation, 1717Massachusetts Ave., N.W., Washington, DC 20036. 1978. $7.50,paper.

Back in 1972, California submitteda "Proposition 20" to the voters. Itsapproval culminated in the passage ofthe 1976 Coastal Act. This book considers, in depth, how management ofCalifornia's extensive coast faredunder that Act. An economist, aland-use lawyer, a marine ecologist,and a public policy expert are amongthe contributors.

Advances in Microbial Ecology. Vol. 2.M/ Alexander, Ed. xiv + 297 pages.Plenum Publishing Corp., 227 West17th St., New York, NY 10011. 1978.$25.50, hard cover.

This review series deals with ecologyof microorganisms in natural andman-made ecosystems. It examinesbacteria, fungi, algae, protozoa, andviruses in freshwater, ocean, soil, andother milieux in which microorganisms are present. Many topics 'lf current interest, such as nutrients,biogeochemical cycles, specializedhabitats, biochemical transformations,and the like, are considered.

Footprints on the Planet: ASearch foran Environmental Ethic. Robcrt Cahn.277 pages. Univcrse, 381 Park AvcnucSouth, Ncw York, NY 10016. 1978.$10.95.

Perhaps there is indeed a new senseof responsibility among businessmento improve the quality of life, and totread more lightly on the planet. Perhaps not all agree with this assessment,but one highly placed industrialist isquoted as saying that it is just goodbusiness to solve the environmentalproblems to the best of ability beforea business starts. The author lists theenvironmental doers and non-doers ofbusiness and industry.

Disinfection of Wastewater and Waterfor Reuse. George Clifford Whitc. 379pages. Van Nostrand Reinhold, 135West 50th St., New York, NY 10020.1978. $24.50.

This book presents the most upto-date information of methods ofdisinfecting wastewater and water forreuse. It discusses disinfectants,chemical usage, supply systems, andequipment in conclusive detail. Ozone,hypochlorite, chlorine dioxide, injector/diffuser systems, alarms, leak detectors, and other pertinent topics arccovered.

National Wetlands Newsletter, Periodical. Environmental Law Institute,Suite 600, 1346 Connecticut Avenue,N.W., Washington, DC 20036. $25for 12 issues.

This newsletter is aimed at promoting exchanges of ideas for bettermanagement of wetlands and noodplains. It carries information of government and private activities, development, research, litigation, and manyother topics pertinent to wetlands.

Alternatives for Growth: The Engineering and Economics of NaturalResources Development. HarveyMcMains, Lyle Wilcox, Eds. xiii +256 pages. Ballinger Publishing Co.,17 Dunster St., Harvard Sq., Cambridge, MA 02138. 1978. $16.50, hardcover.

Can ever-increasing consumption ofenergy and natural resources be permitted? Where will greater supplies offood and fiber come from? Can theexponential growth of technologycontinue? These, and many other suchquestions are discussed in this book,which looks at possible new directionsin natural resource economic and engineering policies. Alternative plansare suggested.

Stormwater Management: Quantityand Quality. Martin P. Wanielista. xiii+ 383 pages. Ann Arbor SciencePublishers Inc., P.O. Box 1425, AnnArbor. MI 48106. 1978. $28, hardcover.

A big thrust to come in water pollution control is to be control of nonpoint sources, such as stormwater. Thisbook looks at such control, and discusses quality aspects and hydrologicalprinciples. Solves problems and casehistories cover now routing, hydrographs, watershed data, quality responses owing to nonpoint sources,urban and rural applications, andmany other pertinent topics.

Clean Fuel Supply. 103 pages. OECDPublications and Information Center,Suite 1207, 1750 Pennsylvania Ave.,N.W., Washington, DC 20006.1978.$6.25.

This work examines sulfur cmissionsin the mid-1980's, and the factors thatwill affect them. For example, back in1968, it was predicted that by 1980,S02 cmissions would reach 95 milliontons; this estimate has now been revised downward. Also, necds for S02reduction to stop detcrioration of lakes,forests, and public health are discussed, as well as problcms of transfrontier pollution. Effects on plans tocut oil imports arc also covered.

World Energy: Looking Ahead to2020. Conservation Commission of theWorld Energy Conference. xviii + 274pages. IPC Science and TechnologyPress, 205 E. 42nd St., New York, NY10017.1978. $32.50, hard cover.

This report gives estimates of thequantity ofenergy which could becomeavailable worldwide during 19852020, if appropriate action is takennow. Estimates are based on availabletechnology, and were evolved by acommittee of experts from 12countries. Intelligent conservation isassumed, and advocated for these estimates. The evaluations were critically examined at the 10th WorldEnergy Conference, held at Istanbul,Turkey, in 1977.

The Science Report on Solar Energy inAmerica. William D. Metz. Allen L.Hammond. xiv + 205 pages. American Association for the Advancementof Science, 1515 Massachusetts Ave.,N.W., Washington, DC 20005. 1978.$18.50, casebound; $8.50, paper.

Where does the U.S. stand in developing solar energy sources andsystems? Some answers are providedin this book, which details diversetechnologies, and their potentials andproblems. Short- and long-range solarenergy prospects are discussed.

The Fear Campaign Against WIPP:Let the Truth Deal with CARD. DavidC. Williams. 12 pages. ANSPI,American Nuclear Society, 555 NorthKensington Ave., La Grange Park, IL60525. 1978. $2.

WI PP is the Waste Isolation PilotPlant proposed for construction nearCarlsbad, NM. CARD is Citizens forAlternatives to Radioactive Dumping,opposed to the WIPP Project. Theauthor draws up a bill of particulars inwhich he acuses CARD 01'27 specificinstances of "misleading implications,and innuendoes, misrepresentations,and downright falsehoods" in CARD'sadvertisements. The author is a staffmember of Sandia Laboratories inNew Mexico.

Environmental Economics: AGuide toInformation Sources. 326 pages. GaleResearch Co., Book Tower, Detroit,MI 48226. 1979. $22.

This work is Volume 8 in the Manand the Environment InformationGuide Series. It stresses a growingconcern with the scarcity of naturalresources, and the best way to allocatethem. It covers economic/environmentpolicy, population, water/air/solidwaste, pesticides, and many other related matters.


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Nol only is a large portion of CUtTen I reference material (including all ACS journals) now availahle in microfiche, you can even arrange to have your own materialput in micl'Ofiche lorm~!\nd sllhscriptions to manyjallrnills and other puhlications cost the same in microficheor printed edition.

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ACS Microforms Program, Room 606Ilmerican Chemical Society,

1155 Sixteentl, Street, N. w., W,lshington, D. C. 20036

(202) 872-4554

March 19-21 Pittsburgh, Pa.Energy and Human Health: HumanCosts of Electric Power Generation.The University of Pittsburgh and theOhio River Basin Energy Study

Write: Edward P. Radford, Dept. ofEpidemiology, University of Pittsburgh,Pittsburgh, Pa. 15261

March 20 Washington, D.C.The Water Pollution Control Federation's 13th Annual Government AffairsSeminar. The Water Pollution ControlFederation (WPCF)

Write: WPCF, 2626 Pennsylvania Ave.,N.W., Washington, D.C. 20037

March 20 Miami Beach, Fla.Wastewater Treatment with Iron VIFerrate. Northwestern University,University of Miami, National ScienceFoundation

Write: Thomas Waite, Department ofCivil Engineering, University of Miami,Coral Gables, Fla. 33124

March 22-23 Miami Beach, Fla.1979 Conference on Control of Hazardous and Toxic Materials in theEnvironment. Hazardous MaterialsControl Research Institute

Write: Hazardous Materials ControlResearch Institute, 4843 Broad BrookDrive, Washington, D.C. 20014

March 23 Oakland, Calif.Carcinogens in the Workplace. TheAmerican Industrial Hygiene Association, Northern California Section

Write: Norman Zeiser, Standard OilCo of Calif., Safety and Industrial Hygiene, Room 1327, 225 Bush St., SanFrancisco, Calif. 94104

April 1-4 Philadelphia, Pa.The Second Annual Technical Conference of the Water Pollution ControlAssociation of Pennsylvania. TheWater Pollution Control Associationof Pennsylvania

Write: G. A. Marburger, P.O. Box 20,Locust Grove, Va. 22508

April 1-4 San Francisco, Calif.The Edison Centennial Symposium onScience, Technology and the HumanProspect. The Electric Power Research Institute and the Thomas AlvaEdison Foundation

Write: Conference Managers, Government Institutes, Inc., 4733 Bethesda Ave..N.W., Washington, D.C. 20014

MEETINGSAprill-5 Houston, Tex.The American Institute of ChemicalEngineers 86th National Meeting. TheAmerican Institute of Chemical Engineers (AIChE)

Write: AIChE. 345 East 47th St., NewYork, N.Y. 10017

Aprill-6 Honolulu, HawaiiThe American Chemical Society andthe Chemical Society of Japan, JointChemical Congress and NationalMeetings. The American ChemicalSociety, and the Chemical Society ofJapan (ACSjCSJ)

Write: A. T. Winstead, ACS, 1155 16thSt., N.W., Washington, D.C. 20036

April2-4 Philadelphia, Pa.Pesticide Meeting. The AmericanSociety for Testing and Materials(ASTM)

Write: D. A. Tobias, ASTM, 1916 RaceSt., Philadelphia, Pa. 19103

Apri117-20 Hollywood, Fla.Environmental Aspects of Fuel Conversion Technology. The IndustrialEnvironmental Research Laboratory-RTP of the U.S. EnvironmentalProtection Agency

Write: Franklin Ayer, Conference Coordinator, Research Triangle Institute,P.O. Box 12194, Research Triangle Park,N.C. 27709

Apri117-20 Rochester, N.Y.Phosphorus Management Strategiesfor the Great Lakes. New York StateCollege of Agriculture and Life Sciences at Cornell University

Write: Raymond C. Loehr, Conferencechairman, Environmental Studies Program, 207 Riley-Robb Hall, Cornell University, Ithaca, N.Y. 14853

CoursesMarch 22-23 Washington, D.C.Environmental Laws and Regulations,Introductory Course. Government Institutes, Inc.

Fee: $335. Write: Government Instilutes, Inc., 4733 Bethesda Ave., N.W ..Washington, D.C. 20014

March 29-30 Valley Forge, Pa.Volatile Organic Compound EmissionControl for the Surface Coatings Industry. U.S. EPA, APCA, NationalPaint and Coatings Association

No fcc. Write: Michael R. Taylor,JACA Corp., 550 Pinetown Rd., FortWashington, Pa. IQ034

April2-5 Cincinnati, OhioOccupational Respiratory Protection.National Inst.itute of OccupationalSafety and Health (N IOSH)

Fee: $250. Write: N10SH, Division ofTraining and Manpower Development,4676 Columbia Parkway, Cincinnati, Ohio45226

April 2-6 Corpus Christi, Tex.National Spill Control School. CorpusChristi State University

Fee: $400. Write: National Spill ControlSchool, Corpus Christi State University,6300 Ocean Drive, Corpus Christi, Tex.78412

April3-5 Rochester, N.Y.Handling Hazardous MaterialsTransportation Emergencies. NationalFire Protection Association

Fee: $120 (member); $130 (non-member). Write: Roberta Frye, National FireProtection Association, 470 Atlantic Ave.,Boston, Mass. 02210

April4 Chicago, III.Application of Retention and RefiningTechnology. The Institute of PaperChemistry

Fee: $35. Write: Kathy Stanek, Continuing Education Office, The Institute ofPaper Chemistry, P.O. Box 1039, Applelon, Wis. 54912

April4 Philadelphia, Pa.Practical Applications of Solar Energy.The Engineers' Club

Fcc: $200. Write. The Engineers' Club,1317 Spruce St., Philadelphia, Pa. 19107

April 4-5 Houston, Tex.Pretreatment-Land Application of Industrial Waste. North Carolina StaleUniversity at Raleigh and the American Institute of Chemical Engineers(A IChE)

Fcc: $225 (members of AIChE); $250(non-members). Write: H. Abramson,AIChE, 345 East 47th St., New York,N.Y. 10017

April 5-6 Dallas, Tex.Stack Sampling Seminar. The Research Appliance Company

Fcc: $295. Write.' Wayne Baker, Director of Training, Research ApplianceCompany, Route 8, Gibsonia, Pa. 15044

ApriI9-13 Lake Tahoe, Nev.How to Use and Design AdvancedWastewater Treatment Processes.Desert Research Institute

Fee: $395. Write: P. A. Krenkel, WaterResources Center, Desert Research Institute, P.O. Box 60220, Reno, Nev. 89506

(continued Oil pag(' 368)


Mr. Mario VillarAnaconda Aluminum

P. 0, Box 523477Miami, Florida 33152

All Equal Opportunity Employe' ""F

AIR QUALITYEnVIROnmEnTAL

EnGinEER

ANACONDA

PROCESS ENGINEER ENVIRONMENTAL

Box E5T 3791AC5, 1155 16th 51. N.W., Washington DC 20036

Anaconda, an expanding division of a major Fortune 100 Corporation, currentlyseeks individual for its Technical Services (Laboratory) Department, to assumeimmediate responsibilities within its Miami facilities.

This position requires a self starter, with a degree in Environmental Science,Chemistry or equivalent. gained through a combination of higher learning andexperience at a technical level in Environmental Control for one to two years.Working knowledge of air sampling equipment. atomic absorption, sound levelmeter, and other general laboratory and industrial hygiene equipment desirable.

We offer excellent starting salary and comprehensive benefit package. Forconfidential consideration. submit your resume and salary history to:

We are an industry leader providing for professional growth and offering anattractive compensation/benefits program. You are invited to send your resumein strictest confidence to:

Requirements: Degree in engineering or meteorology with at least 5 years ofrelated experience, Strong communications skills as well as thorough knOWledgeof air quality regulations are essential. Additionally, experience in atmospheredispersion modeling and ambient air studies is highly desirable,

This unique position's responsibilities would include interfacing with regulatoryagencies on permit applications and compliance plans, developing and presenting comments on proposed regulations, assisting in the development andimplementation of air quality programs and coordinating air quality programsbetween the plant and corporate levels.

A Fortune 150 metals producer has an exceptional opportunity at its Virginiaheadquarters location for an Air Quality Environmental Engineer to serve onits Corporate Central Engineering Staff,

CLASSIFIED SECTION • POSITIONS OPEN

Interna tional

May 8-10 l.ondon, EnglandSulfur Emissions and the Environment.The Society of Chemical Industry,Water and Environment Group

Write: Conference Secretariat. Societyof Chemical Industry. 14 Belgrave Square,London SW I X 81'S England

May 8-11 Stockholm, SwedenProtection '77. Stockholm International Fairs

This is an international trade show, withproducts and services for work safety. environmental protection, and fire protection.Write: Stockholm International rairs, S09Madison Ave., New York, N.Y. 10022

April 6-11 Kyoto, JapanThe 6th International Conference andExhibition on Liquefied Natural Gas.The International Gas Union, the Institute of Gas Technology, and theInternational Institute of Refrigeration

Write: Institute of Gas Technology.3424 South Statc St.. Chicago, III.60616

April 9-11 Oxford. EnglandRiver Pollution Control Conference.The Wa ter Resea rch Cen ter

Write: Confcrenee Organi7.er. WaterResearch Centcr. Medmenham Laboratory, P.O. Box 16. Marlow. Bucks 5172HD. England

Apri125-27 Mexico City, MexicoThe First World Conference on Continuing Engineering Education. TheUnited ations Educational, Scientificand Cultural Organization

Write: John Klus, University of Wisconsin-Extcnsion, Dept. of Engineering &Applied Science, 432 N. l.ake St., Madison, Wis. 53706

April 2-7 Cambridge, EnglandThe Second International Conferenceon Fluidization. The EngineeringFoundation

Write: The Engineering Foundation.United Engin~eringCenter, 345 East 47thSt., New York, .Y.IOOI7

April3-6 Bedford Way. LondonBritish Occupatiollal Hygiene SocietyAnnual Conference 1979. The BritishOccupational Hygiene Society

Write: D. Doran, British Airways(BAMS), Heathrow Airport, Hounslow,London TW6 2.1A. England

I\IFETlN(;S (.."Illilll/l'd)

.\llrii III Philadelphia, Pa.1Il'1l'ar Power Engineering- Projectlanagell1ellt and the Concerns of the

Puhlie. The Engineers' Club of Phila- ~!~~~~~~~~~~~~~~~;;;;~;;;;;;;;delphia ~

F~~: $~OO. Wrile: The Engineers' Club1'1. I'hi"'ddphia. Education Commillee,1.117 Spru~~ St.. Philadelphia, Pa. 19107



ENVIRONMENTAL SCIENTISTS AND BIOLOGISTSThe Research Institute of the University of Petroleum & Minerals, Dhahran, Saudi Arabia, has immediate openings for the following positions:

1. WATER QUALITY SCIENTIST:Responsibilities include experience in new analytical technique and thorough background in water chemistry studies, statistical data interpretationand report preparation. Should be able to apply and employ a wide variety of instrumentations used in water pollution. Qualifications shouldinclude an M.S. or equivalent in Environmental Chemistry or related field. At feasl four years or related experience is necessary.

2. AIR QUALITY SCIENTIST·Applicants should have a minimum of a Master Degree in Environmental Science or related field with experience in air quality investigationincluding the application of a wide variety of instrumentations used in air pollution. Must have the ability to interpret data, prepare and reportfindings in good writing skills. At least four years of related experience is necessary.

3. RESEARCH BIOLOGIST:Responsibilities include experience in marine biology and fisheries. Applicant must hold a university degree in this specialty with a thoroughbackground in the chemistry of water and air in addition to his field. Duties will include field sampling, bioassay capabilities, laboratory analyses,data handling and report writing. Experience in this field is a great factor in selecting applicant. M.S. degree or equivalent ;s preferred.

Minimum regular contract for two years, renewable. Competitive salaries and allowances, all earned income without Saudi taxes. Free air conditionedand furnished housing. free transportation to and from Dhahran annually. Attractive educational assistance grants for school-age children. Localtransportation allowance in cash each month. Ten and a half month duty each year with 45 days vacation paid.

Apply with complete resume on academic and professional background, list of references and with copies of degrees/testimonials, including personaldata such as home and office address. telephone numbers. family status (spouse's name. names of children, ages and sex) to:

The Research Institute, University of Petroleum & Mineralsc/o Saudi Arabian Educational Mission

2223 West Loop South, Suite 400, Houston, Texas 77027

ELECTROSTATIC PRECIPITATORSCIENTISTS. ENGINEERS

DENVER RESEARCH INSTITUTE requires Ph.D.or M.S. in Physics. Electrical. or MechanicalEngineering in expanding R&D programssponsored by several government agencies andindus1rial organizations. Activities includetheoretical studies 01 electrostatic fields andHigh Voltage Supply control; charging. collection. and adhesion phenomena: design,fabrication, and installation of bench-scalethrough pilot-scale precipitators: ESP consultation and analysis. Two years experience inone or more of these topics and two more yearsin related R&D engineering are desirable. Fourto six years experience in closely-related activities at a high technical level will be considered. Send resume and salary history to:

Mrs. Phyllis Riggs

DRI/ElectronicsUniversity of Denver

P.O. Box 10127, Denver, Colorado 80210"The University 01 Denver (Colorado Seminary) is an

Allirmative Action Equal Oppotlunity Employer'

University of Pennsylvania has a tenure-trackfaculty position open at the level of AssistantProfessor in the Department of Civil and UrbanEngineering. The candidate should have a Ph.D.and professional experience is desirable. Dutieswill include: teaching undergraduate and graduate courses in environmental systems; participation in team research (e.g., life cycle studiesof resources. environmental management);development of independent research activities.Reply with credentials to: Or. John D. Keenan.Chairman of Search Committee. Department 01Civil and Urban Engineering, Towne Building0/3. University of Pennsylvania. Philadelphia.PA. 19104. The University of Pennsylvania is anequal opportunity/affirmative action em·ployer.

General Motors Environmental Activity Staffhas need for

SENIORENVIRONMENTAL ENGINEER

WASTEWATER MANAGEMENTRequires individual with B.S. in environmental, civil or chemical engineering,

plus experience in wastewater management preferably in joint municipal/industrialsystems and, of course, working knowledge of the Federal Water Pollution ControlAct. M.S. level training and familiarity with aquatic biology would be preferred.The ideal candidate will have experience either with a regulatory agency, consultant or an industrial firm in water pollution control.

Wilt be responsible for technical review of laws and regulation in water pollutioncontrol and assisi our plants and divisions in waste water programs.

Applicants must be able to legalty accept permanent employment under U.S.Laws.

In addition, openings exist for experienced personnel with appropriate professionalbackgrounds in automotive emissions, fuel economy. emission data analysis andautomotive safety engineering.

Applicants can send resume and salary requirements to:

Personnel Administration 26 P-ES

IIGENERAL MOTORSTECHNICAL CENTERWARREN, MICHIGAN 48090

We Are An Equal Opporlumt.- Employer



MarineMicrobiologist

Kuwait Institute forScientific Research

Overseas AssignmentThe Kuwait Institute for Scientific Research, a rapidly expandinginstitute for applied science and technology, is seeking a MarineMicrobiologist who is interested in the opportunity for a careerchallenge.While supervising technicians in the field, you will be maiorlyresponsible for conducting microbiological investigations todetermine biological indicators of oil pollution; expandingsewage pollution studies along Kuwait City; and initiation of teststo screen pollutant compound for carcinogenicity.

We require a PhD in microbiology and previous supervisoryexperience.

Kuwait Institute offers attractive salaries commensurate withqualifications and experience, furnished housing, liberal fringebenefits including round trip air tickets and free medical benefits.Please airmail complete resume by April 1, 1979 10: Mr. HabibAI-Sahhaf, Personnel Manager, Kuwait Institute for ScientificResearch, P.O. Box 24885, Safal, Kuwait, State of Kuwail.

June 8-July I Hamburg, W. GermanyThe International Transport Exposition, IV A '79. Bundesregierung unterFcderfuhrung dcs Bundesministers fUrVerkehr und Senat der Freien undHansestadt Hamburg

Write: Hamburg Messe und CongressGmbH, Jungiusstrasse 13, Postfach 30 2360. D 2000 Hamburg 36, W. Germany

June 11-15 Taipei, TaiwanPollution Controls USA. U.S. Department of Commerce

Write: Dave Horridge, Project Manager, Office of International Marketing/Room 3016. U.S. DOC. Washington, D.C.20230

April 15 deadlineWorkshop on Combined and SeparateTreatment of Domestic and IndustrialWastewater in Large Plants. The International Association on WaterPollution Research (IA WPR)

Conference will be held September 3-7,1979 at Vienna, Austria. Write: Ing. Wilhelm v.d. Emde, Institute fur Wasserversorgung, Abwasserreinigung und Gewasserschultz, T U Wein, Karisplatz 13, A1040 WIEN. Austria

March 31 deadlineForecasting Planning and Programming in the Chemical Industry. TheChemical Industry Committee of theUnited Nations Economic Commission for Europe (ECE)

Conference will be held September10-14.1979 at Warsaw, Poland. Write:Industry Division. U.N. Economic Commission for Europe. Palais des Nations,CH- I2 I I, Geneva, 10, Switzerland

Call for Papers

May 14-16 London, EnglandHuman Health and EnvironmentalToxicants. The Royal Society ofMedicine Foundation and the RoyalSociety of Medicine

Write: Conference Secretary, RoyalSociety of Medicine I Wimpole St., London WI M 8AE, England

June 3-6 Vancouver, British ColumbiaThe 62nd Canadian Chemical Conference of The Chemical Institute ofCanada. The Chemical Institute ofCanada

Write. The Chemical Institute of Canada. lSI Slater St.. Suite 906, Ottawa,Ontario, Canada KIP 5H3

May 9-12 Salzburg, AustriaThe 4th International Trade Fairfor Environmental and MunicipalTechnique and Laboratory Equipment. Osterreichischer Wasserwirtschaftsverband and others

Write: Contact Fachmcssen Salzburg,Ges.m.b.H & Co. KG, Postfach 285, A5021 Salzburg. Austria

-

IMPORTANT NOTICE

Environmental Engineer-Salary 20K to 25K, excellent fringe benefits. Registration desired. Responsible lor aiding in site selection, fuel supply, licensing 01 power projects. Submit confidential resume to Royal B. Newman, Executive Vice President and General Manager. Soyland Power Cooperative, Inc., P. O. Box A1G06, Decatur. Illinois62525. Phone (217) 423-8000.

AIR QUALITY SCIENTISTIENGINEER to conductair quality and meteorological data analyses forenvironmental assessment program. RequiresB.S. or M.S. in environmentally related disciplinewith three years of professional experience;proven capabilities in atmospheric dispersionmodeling and analyses of associated air qualityand meteorological data; and good communication skills. Field experience in air quality monitoring and data processing desirable. Minimumstarling salary $22,000, liberal benefits. Sendapplication, postmarked by March 31. 1979. toMrs. T. Harrison, Desert Research Inslitute,Universily of Nevada Syslem, P.O. Box 60220,Reno, Nevada 89506. Affirmative Action/EqualOpportunity Employer.

Various slate laws against discrimination and the Federal CivilRights Act of 1964 prohibit discrimination in employment because of race. color. religion. nalional origin. age, and sex(unless based on a bona fide occupational qualificalion) Helpwanted and situations wanted advertisements on these pagesare for readers convenience and are not to be construed asinstruments leading to unlawful discrimination.

Classified Advertising Department25 Sylvan Rd. SouthWestport, CT. 06880

(203) 226-7131

Environmental Science& Technology

CLASSIFIEDADVERTISING

RATES

Rate based on number of insertions used within 12 monthsfrom date of first insertion andnot on the number of inchesused. Space in classified advertising cannot be combined forfrequency with ROP advertising.Classified advertising acceptedin inch multiples only.Unil 1·T 3-T 6-T 12-T 24-T1 inch $63 $60 $58 $56 $54

(Check Classified AdvertisingDepartment for rates if advertisement is larger than 10".)SHIPPING INSTRUCTIONS:Send all material to

-


professional consulting services directory

• AIR. WATER. SOLIDS. NOISE. ODOR

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SOURCE & AMBIENT AIR TESTING

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(;on<'uli"I1\'. (n~lfleefs.ConslfllCtorslnVlfonmel1l,11 Svslems Dlvls.on

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LabOr,ltory ,Inc! PIOceSS Development ~tncluslrltll W;:lste Waler ControlLIQUid ilnd SOlid InCineration

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Write for brochure,., r •.• rnFflaOL.LDB~YTICAL

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• Dredge and Fill Permits• Reclamation Programs• Aquatic System Restoration• Environmental Monitoring• Analytical Laboratory• Bioassay• Environmental Licensing• Limnological StUdies• Environmental Impact Statements

I~Breedlove Associates Inc.~ Environmental Consultants

AIR & WATER

STACK &EXHAUST TESTSCONSULTING. LABORATORY

Environmental Systems DIvISionHeadquarters' San FrancIsco. CA

• Site Selection Studies• Impact Assessment

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.NUSCORPORATION

Environmental services.air and water pollutioncontrol engineeringand consulting

4 Research PlaceRockville. Md 20850301/948-7010TWX 710-828-0540

•Orher ol/Ices If) Cili/on NJ • Was!llllgfon 0 C~ Anchorage AK • San Diego. CA .."J

,. Woodward.Clyde ~..""IIIIlConsultants ~

SONICSINTERNATIONAL, INC.

MO~SJ~IO MISfJMCH CORPORJIIO~

AOlA SIArlON8!IUION OHIO 1~IOl

AlIN 0 A /ill SO~ I~IJI 168 l~lI

Over 20 years industrial serviceAll projects designed to meet your

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Stationary/Ambient Air Quality StudiesOSHAlindustrial Hygiene Applications

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Other services availableClass I Liquid Waste Disposal Wells

Oil Field Water Quality Studies

_ Housion, TX (713) 479·6084

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Particulates •.~erosols.Odor. Smoke

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CAMP DRESSER & McKEE INC.Engineering & Tesling Consu'fonh

O!I,( es 1nrougnout the uSCherry Hill, N.J. (609) 424·4440Charlotte. N.C. (704) 333-8411

One Center PI(ll(1Atlanta, GA. (404) 377·4248South Euclid, OH. (216) 382-1719 Boston Ma<:''''i1chllsel1s 07108

lAB SAFEn CDMSend for 1979 Catalog environmental engrneers. SCIentists.

LAB SAFETY SUPPLY CO.planne,s. & management consultants

P.O.Box 1368, Janesville, WI 53545

Voiume 13. Number 3, March 1979 371

WRITE FOR CATALOG

371-372

PAGE NO.

368-370

Advertising Management fo< theAmerican Chemical Society Publications

AHred l. Gregory

PRODUCTION DEPARTMENT

PRODUCTION DIRECTOR

Joseph P. Stenza

PRODUCTION MANAGER

Diane C. McGralh

CENTCOM, LTD.

Thomas N, J. Koerwer, President; James A.Byrne, Vice President; Clay S. Holden, VicePresident; Benjamin W. Jones. Vice President; Robert L. Voepel, Vice President; 25Sylvan Rd, South, Westport, Connecticut06880 (Area Code 203) 226-7131

ADVERTISING SALES MANAGER

SALES REPRESENTATIVESAtlanta. Ga, ... Robert E. Kelchner, CENTCOM,

LTD.. Phone (Area Code 203) 226-7131Boston, Ma.... Anthony J. Eagan, CENTCOM, LTD..

(Area Code 212) 972·9660Chicago, II. ... John McGuire, CENTCOM, LTD., 540

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Cleveland, Oh.... Bruce Poorman, CENTCOM,LTD., 17 Church SI., Berea, OH 44017 (AreaCode 216) 234-1333

Denver, Co, ... Clay S. Holden. CENTCOM, LTD.,(Area Code 213) 325-1903

Houston, Tx, ... Robert E. LaPointe, CENTCOM,LTD., (Area Code 415) 781-3430

Los Angeles, Ca, ... Clay S. Holden, CENTCOM3142 Pacific Coast Highway, Suite 200. Torrance, CA 90505, (Area Code 213) 3251903

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Manchester, Engfand . .. Jill E. Loney, Technomedia Ltd., 216 Longhurst lane, Mellor.Stockport SK6 5PW. Telephone: 061·427-5660

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Tokyo, Japan ... Haruo Moribayashi, InternationalMedia Representatives ltd.. 2-29 Toranomonl-chrome. Minato-Ku, Tokyo 105 Japan.Telephone: 502-0656

CLASSIFIED SECTION

PROFESSIONAL CONSULTINGSERVICES DIRECTORY , • , , • ,

PAGE NO.

294

CIRCLEINQUIRY NO.

1 ." •• , Alpkem CorporationAlpkem AdvertisingCompany

15 "." Yale UniversityPress".,., •• , ••• ", , 359

Carleton H. StevensAdvertising

Campbell-EwaldCompany

275,294

10-11 •• Foxboro Analytical" 260, 356Shepherd, Tibball& Galog

2 ,."" Barringer Researchltd, ".""., ••• "", 359

3 ,.".,The Bendix Corporation IBCD'Arcy, MacManus &Masius, Inc.

6 " ••.. Mast DevelopmentCompany """.",." 294

Warren &Litzenberger

20 "".The CarborundumCompany "",." •• ". 259

Rumrill·Hoyt,Inc.

18, , •• ,. Beckman InstrumentsInc, "., •• " •• ,.".". OBC

N W Ayer ASHInternational

16 ., •• ,Gow-Mae InstrumentCompany , ••.••• ,.",. 276

Kenyon HoagAssociates

8 ."." ERT , •• ".",.", •• ,. 253Impact AdvertisingInc.

19 "., ,ISCO .""",." •• ,.. 258Farneaux Associates,Advertising

17 ."., DuPont •• , , •• , , •• , , , • • 265N W Ayer ABHInternational

S •• , •• , Martek "" •• ,.",' •• , 256Tekmar MarketingServices

22-23 "Rockwell International

12 "".Research ApplianceCompany , •• ,."" •• " IFC

W F Minnick &Associates, Inc.

13 ."., Rohm & Haas 263AI Paul LeftonCompany Inc.

14 ., •. , Sierra-Misco ., ••• "", 294The Agency

7 , •• , •• Tracor AnalyticalInstruments .",.", •• , 273

Aim AdvertisingAgency

INDEX TO THE ADVERTISERS IN THIS ISSUE

Mobile. Ala

1501 N.8'o.dw.yW.lnul C,eek.

CA 94596

(4151 937·9010

r 1,;> I ~ ,Mi 11 ~ l'J; :'·'lJ'." lQ';J.'',... ,:.0., Ut,U!

SCHNEIDERCONSULTINGENGINEERS

BROWNAND CALDWELLCONSULTlNG ENGINEERS

HAVENS ANDEMERSON, INC.Environmental Engineers

Cleveland,OH Saddle Brook, NJ

Atlanta, GA St. Louis, MO

-ENVIRONMENTAL AND FACILITIESPlANNING. DESIGN. AND CONSTRUCTION MANAGEMENT

FOR INDUSTRY AND GOVERNMENT

Bolon Rou e. Lo

;;>22' W 'J'" '" i,' p' '/,1 . C' ("1' L hllti06\;"'" 1000]

· "",".: ;'l;l!U

lin_ J. E. SIRRINE COMPANY

98 VANADIUM ROAD. BRIDGEVillE. PA. 15011(412)563.6100

$~t&.4?1LABORATORIES INC.

545 Comme:fC( Sr Franld'n Ldku, N J 07417201.337.4774 201·891.8787

• Atomic AbIors»tlon • Optfc.l Emlnlon• Ch'mlc.l • X....y *ctfomdry

Compldt Andlytlcal Srrv,crs for[nvuonmrntdl St,Jdles &: Pollution Control

ENVIRONMENTAL ENGINEERINGSource Control _ Waste Treatment • Solids Handling

Reclamation. Energy and Resource RecovervOperations Consultation laboratory Analysesand Training Since 1947 and SurveysATLANTA 'ASAOENA SEAnLE WALNUT CI'lEEI(

EUGENE SACI'lAMENTO TUCSON

CHARLES R VELZYASSOCIATES, INC.

CONSULTING ENGINEERSWATER POLLUTION COtHROL • SOLIDWASTE DISPOSAL. AIR POLLUTIONCONTROL. INDUSTRIAL WASTES.

DRAINAGE. WATER SUPPLY3SS Main StreetArmonk, N.Y. 10504

Mineola New York Babvlon, New York

GREELEY ANO HANSEN

professional. consultingservices directory

'.· ...A:II ' 'l ,1 ....... ·

'''''''','Hlh 11\· ·.~l!v, 1 I til v',! V\1i\ 'I H .. "\;1

Enlilln••r, Sinn 1902 An Employ.. Dwn.ci Compeny

Complete Design ofEnvironmental Facilities

USA Greenvrlle. SC. 29606 • Houston. TEX. 77027Ralergh. NC 276C7 0 Riyadh. Saudi Arabra

W WALK, HAYDEL & ASSoCIATES,INC.Complete Environmental Serviu.

Refineries, Chemical PlantsFertilizer Facilities. Pipelines. Docks.Oil & Gas Offshore Facilities. Terminals

600 Carondelet S1.. New Orleans.la. 70130504·586·8111

•


TO VALIDATE THIS CARD, PLEASE CHECKONE ENTRY FOR EACH CATEGORY BELOW,

ZIP,

ES&T MARCH 1979 vALiD THROUGHJULY 1979

ADVERTISED PRODUCTS, 1 2 3 4 5 67 8 9 10 11 12 13 14 15 16 17

18 19 20 21 22 23 24 25 26 27 2829 30 31 32 33 34 35 36 37 38 3940 41 42 43 44 45 46 47 48 49 5051 52 53 54 55 56 57 58 59 60 6162 63 64 65 66 67 68 69 70 71 7273 74 75 76 77 78 79 80 81 82 8384 85 86 87 88 89 90 91 92 93 94

NEW PRODUCTS, 101 102 103 104 105 106 107108 109 110 III 112 113 114 115 116 117 118119 120 121 122 123 124 125 126 127 128 129130 131 132 133 134 135 136 137 138 139 140141 142 143 144 145 146 147 148 149 150 151152 153 154 155 156 157 158 159 160 161 162163 164 165 166 167 168 169 170 171 172 173174 175 176 177 178 179 180 181 182 183 184185 186 187 188 189 190 191 192 193 194 195

NAML

TITLE,

FIRM,

STREET,

CITY,

STATL

PHONE,

Intensity of product need:o 1. Have salesman callo 2. Need within 6 monthso 3. Future project

Employees atthis location:o 1. Under 25o 2. 25·99o 3. 100·29904.300·499o 5. 500·999o 6. 1000·2999o 7. Over 3000

Areas of yourresponsibility:o A. Air pollution onlyo B. Water pollulion onlyo C. Waste treatment onlyo O. Air & Water pollutionlIE. Air & Waste treatmentis F. Water & Waste treat.o G. Air/Water/wasteo H. other Environmental

ThiS copy of ES&T is .~-l L Personally addressed- to me in my nameo 2. Addressed to other

person or to my firm.

III II I

Princ"ipal product towhich my work relates:o A. Oil/Gas/Petroleumo B. Plasticsl ResinsC C. Rubbero D. Drugs/Cosmeticso E. Food/ Beverageso F. Textile/Fibero G. Pulp/Paper/Woodo H. Soaps/Cleanerso I. Paint/Coating/lnko J. Agrichemicalso K. Stone/Glass/Cemento L. Metals/Miningo M. Machineryo N. Auto/ Aircrafto O. Instrument/Controlso P. Inorganic Chemicalso Q. Organic Chemicalso R. Other Manufacturingo S. Design/Constructiono T. Utilities[J U. Consulting Serviceso V. Federal Governmentn W. State Governmento X. Municipal Governmento Y. Education

Membership status:o 1. 1am an ACS membero 2. Not an ACS member

Circle 94 forSUbscriptionform to ES&T

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UNITED STATES J

BUSINESS REPLY CARDFIRST CLASS Permit #27346 Philadelphia. Pa.

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EnvironmentalScience & Technology

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Circle 94 forSUbscriptionform to ES&T

Membership status:o 1. I am an ACS membero 2. Not an ACS member

Principal product towhich my work relates:o A. Oil/Gas/Petroleumo B. Plastics/ResinsDC. Rubbero D. Drugs/ Cosmeticso E. FoodfBeverageso F. Textile/Fibero G. Pulp/Paper/Woodo H. Soaps/Cle~ners

o l. Paint/Coating/Inko J. Agrichemicalso K. Stone/Glass/Cemento L. Metals/Miningo M. Machineryo N. Auto/ Aircrafto 0, Instrument/Controlso P. Inorganic Chemicalso Q. Organic Chemicalso R. other Manufacturingo S. Design/Constructiono T. Utilitieso U. Consulting Serviceso V. Federal Governmento W. State Governmento X. Municipal Governmento Y. Education

This copy of ES&Tis ..o 1. Personally addressed

to me in my nameo 2. Addressed to other

person or to my firm.

Areas of yourresponsibility:o A. Air pollution onlyo B. Water pollution onlyo C. Waste treatment onlyo D. Air & Water pollution!J E. Air & Waste treatmentOF. Water & Waste treat.o G. Air/water/Wasteo H. Other Environmental

TO VALIDATE THIS CARD, PLEASE CHECKONE ENTRY FOR EACH CATEGORY BELOW,

Employees atthis location:o I. Under 25o 2. 25 - 99o 3. 100" 299o 4. 300 - 499[] 5. 500 - 999o 6. 1000 - 2999o 7. Over 3000

Intensity of product need:o 1. Have salesman callo 2. Need within 6 monthso 3. Future project

61728395061728394

51627384960718293

41526374859708192

VALID THROUGHJULY 1979

31425364758698091

21324354657687990

11223344556677889

------ ------

ES&T MARCH 1979

NEW PRODUCTS, 101 102 103 104 105 106 107108 109 110 III 112 113 114 115 116 117 118119 120 121 122 123 124 125 126 127 128 129130 131 132 133 134 135 136 137 138 139 140141 142 143 144 145 146 147 148 149 150 151152 153 154 155 156 157 158 159 160 161 162163 164 165 166 167 168 169 170 171 172 173174 175 176 177 178 179 180 181 182 183 184185 186 187 188 189 190 191 192 193 194 195

ADVERTISED PRODUCTS,7 8 9 10 11

18 19 20 21 2229 30 31 32 3340 41 42 43 4451 52 53 54 5562 63 64 65 6673 74 75 76 7784 85 86 87 88

STREET,

FIRM,

NAME, ._

TITLE,

CITY, _

STATE, _ _ __. ZIP, __

PHONE, ( ) " _

I

--------------------------------------------------------------------._--~II,I,,I,,III

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You also get optional telemetryelectronics that activate remotealarm indicators through dedicatedtelephone lines.

If you have special needs, we canadapt the system to meet them. Tohelp cranes keep thei r sea legsduring high winds.

For more information, contact:The Bendix Corporation, Environmental & Process InstrumentsDivision, 1400 Taylor Avenue,Baltimore, Maryland 21204.Phone: (301) 321-5200.

We spe~J~.J~~hnolog~

Now look for more than EPA designationLook for the name.

Beckman.Today. all good air monitoring

instrumentation carries an EPA designation-otherwise. who'd buy it'!

But that leaves you with aproblem. How do you choose the bestfrom among the good'! How do you

, cl100se the analyzer that's best for your. p.articular CO. OZONE, N02 and S02

monitoring need'? We say. look for the,riame.;[[ it's'Beckman. you kow thetradition and reputation behind it.You know you're getting the best~Takethese four EPA-designated models ...

Model 953 Fluorescent Ambient502 Analyzer Utilizing the fluoreseent measuring technique. theBeckman 953 requires none of the support gases and reagents typicallyassociated with S02 analyzers usingflame photometry or coulometricmethodologies. As a result. the 953offers outstanding performance atlower operating costs. with easy serviceability. Features include: fastresponse. low operating noise.interference-free measurement.t~mperature controlled case. optional

digital readout. BCD output. Beckmandirect sales and service.

Model 952A NO/NO, N02Anal)'Zllr The Beckman 952A providesanalysis and continuous analogvoltage outputs for all three parameters-NO, NO; and N02-usingthe chemiluminescent method ofanalysis. Features include: self contained system employing ambient airfor ozone generation. interferencefree measurement. unlimited lifeconverter. selectable outputs forrecorders. computers or telemetry.bench or rack mounting.

Model 950A Ozone AnalyzerOperating on the chemiluminescentprinciple. the Model 950A providesa wide selection of full scale rangesfor ambient air monitoring with highprecision and accuracy. Featuresinclude: non-hazardous mixture ofC02 and ethylene, chemical filter forinterference-free zero calibration.automatic safety shutoff valve forreactent gas, selectable outputs forrecorders. computers or telemetry.


and uses bench or rack mounting.Model 866 Ambient CO Moni·

toring System The completely self·contained Model 866 consists of:NDIR Analyzer. Pump/SampleHandling Module. Flow and Reference Panel. Automatic Zero/SpanStandardizer. Features inlcude: longterm unattended operation. betterthan 50.000: I H20 discrimination,automatic zero and Span correction's,field-proven NDIR analyzer. no zerol

gas cylinders. high energy sources toimprove sensitivity.

For more information on theseinstruments or on any air qualitymonitoring requirement you mayhave. contact Process InstrumentsDivision. Beckman Instruments. Inc,2500 N. Harbor Boulevard. FullertonCA 92634.Why settle for good when you can .get the best?

BECKMAN

environmental science & technology 1979 vol.13 no.3

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