tekran ® automated mercury speciation f.h. schaedlich 1, robert k. stevens 2, d.r. schneeberger 2,...

TekranTekran®® Automated Mercury Automated Mercury SpeciationSpeciation

F.H. Schaedlich1 , Robert K. Stevens2,

D.R. Schneeberger2 , Eric Prestbo3,

Steve Lindberg4 , Gerald Keeler5

F.H. Schaedlich1 , Robert K. Stevens2,

D.R. Schneeberger2 , Eric Prestbo3,

Steve Lindberg4 , Gerald Keeler5 1 Tekran Inc., 1-132 Railside Rd. Toronto, Canada M3A 1A3, 1 Tekran Inc., 1-132 Railside Rd. Toronto, Canada M3A 1A3, 2 Florida Dept. Environmental Protection at USEPA, Res Triangle Park, NC 27711,2 Florida Dept. Environmental Protection at USEPA, Res Triangle Park, NC 27711,3 Frontier Geosciences Inc., 414 Pontius Ave. N., Suite B, Seattle, WA 981093 Frontier Geosciences Inc., 414 Pontius Ave. N., Suite B, Seattle, WA 981094 Oak Ridge National Lab. PO Box 2008, Oak Ridge, TN 37831-60384 Oak Ridge National Lab. PO Box 2008, Oak Ridge, TN 37831-60385 University of Michigan, School of Public Health, 109 Observatory Street, MI 48109.5 University of Michigan, School of Public Health, 109 Observatory Street, MI 48109.

Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation

ObjectivesObjectives

Development of Development of automated methodsautomated methods to to measure and differentiate between:measure and differentiate between: Reactive Gaseous Mercury (Reactive Gaseous Mercury (RGMRGM) in ambient ) in ambient

airair Total Particulate Mercury (Total Particulate Mercury (TPMTPM) in ambient air ) in ambient air Elemental mercury (Elemental mercury (HgHg00) in ambient air) in ambient air


Ambient Air Mercury SpeciationAmbient Air Mercury Speciation

Different forms of gaseous Hg have very Different forms of gaseous Hg have very different behaviors.different behaviors.

Forms can interconvert in the atmosphere Forms can interconvert in the atmosphere and in various reservoirs.and in various reservoirs.

Classes of mercury in ambient air:Classes of mercury in ambient air: Elemental mercury: Elemental mercury: HgHg00.. Reactive mercury: Reactive mercury: HgHgIIII, , RGMRGM, , HgHg2+2+.. Particulate mercury: Particulate mercury: HgHgPP, , TPMTPM..


Model 2537A Mercury AnalyzerModel 2537A Mercury AnalyzerProvides continuous total gaseous (Provides continuous total gaseous (TGMTGM) )

readings with update rate as low as readings with update rate as low as 2.52.5 minutes.minutes.

Detection limit Detection limit < 0.1 ng/m< 0.1 ng/m33 (5 min. samples).(5 min. samples).

Automatic recalibration with internal HgAutomatic recalibration with internal Hg00 permeation source.permeation source.

Capable of unattended operation for extended Capable of unattended operation for extended periods.periods.


Model 2537A AnalyzerModel 2537A Analyzer


Flow Diagram of Model 2537A Flow Diagram of Model 2537A Mercury AnalyzerMercury Analyzer


Elemental Mercury: HgElemental Mercury: Hg00

Typically 90+% of atmospheric Hg Typically 90+% of atmospheric Hg loadings.loadings.

Relatively inert. Long residence time.Relatively inert. Long residence time.

HgHg00 sources impact large areas. sources impact large areas.

Sources: chlor-alkali plants, gold and Hg Sources: chlor-alkali plants, gold and Hg mining, thermal power plants.mining, thermal power plants.

Part 1Part 1Reactive Gaseous Reactive Gaseous

Mercury MonitoringMercury Monitoring


Why Bother Measuring RGM ?Why Bother Measuring RGM ?

RGMRGM (as (as HgClHgCl22) is emitted from power ) is emitted from power

plants and incinerators.plants and incinerators.

RGMRGM is removed rapidly via wet and dry is removed rapidly via wet and dry deposition.deposition.

Often responsible for contamination of Often responsible for contamination of sensitive nearby ecosystems. sensitive nearby ecosystems. (Florida (Florida Everglades, Arctic).Everglades, Arctic).


Reactive Mercury: Hg(II) or RGMReactive Mercury: Hg(II) or RGMConsists of reactive, water soluble forms, Consists of reactive, water soluble forms,

primarily HgClprimarily HgCl22..

Usually only a few percent of total gaseous Usually only a few percent of total gaseous mercury present in the atmosphere.mercury present in the atmosphere.

Short range: deposits relatively close to the Short range: deposits relatively close to the source of emission.source of emission.

Primary sources: Coal burning power plants, Primary sources: Coal burning power plants, waste incinerators. waste incinerators. ((Chlor-alkali plantsChlor-alkali plants??))


Difficulties Measuring RGMDifficulties Measuring RGMMethod must be 1-2 orders of magnitude Method must be 1-2 orders of magnitude

more sensitive than total mercury more sensitive than total mercury methods.methods.

Reject much larger Reject much larger elementalelemental component. component.

Exclude Exclude particulateparticulate bound mercury, bound mercury, however, particulate filters have problems however, particulate filters have problems passing passing RGMRGM..

Apparatus must pass Apparatus must pass RGMRGM to the collector to the collector quantitatively.quantitatively.


Model 1130 - Principles of OperationModel 1130 - Principles of Operation

Quartz, specially coated annular denuder is Quartz, specially coated annular denuder is thermally desorbed and regenerated.thermally desorbed and regenerated.

Sampling Phase.Sampling Phase. Absorbs RGM while passing all elemental Hg.Absorbs RGM while passing all elemental Hg. Model 2537A reads Model 2537A reads HgHg00 during this phase. during this phase.

Desorption/Analysis Phase.Desorption/Analysis Phase. Zero air used as carrier.Zero air used as carrier. RGM released as RGM released as elementalelemental mercury. mercury.


RGM Sampling PhaseRGM Sampling PhaseDenuder is slightly warm.Denuder is slightly warm.

Inlet slightly warm.Inlet slightly warm.

Denuder captures all Denuder captures all RGM while passing HgRGM while passing Hg00..

Total sample flow is Total sample flow is 10 10 lpm.lpm.

Analyzer measures HgAnalyzer measures Hg00 during this time.during this time.

ZeroAir

SamplePump

MERCURY VAPOUR ANALYZER 2537A

AnnularDenuder

InletHeater

9 lpm 1 lpm

off

DenuderHeater

Ambient Air

OptionalModel 1135

Particulate Unit

Sampling Phase

Warm 50 ºC


Analysis PhaseAnalysis PhaseDenuder is heated to Denuder is heated to

500500C.C. Inlet heated to clean Inlet heated to clean

upstream glassware.upstream glassware.Denuder releases captured Denuder releases captured

RGM as HgRGM as Hg00..Excess zero air flow cleans Excess zero air flow cleans

upstream components.upstream components. Instrument measures Instrument measures

accumulated RGM as Hgaccumulated RGM as Hg00..

ZeroAir

SamplePump

MERCURY VAPOUR ANALYZER 2537A

AnnularDenuder

InletHeater

off 1 lpm

6 lpm

DenuderHeater

ExcessZero Air

Heated 500 ºC

Desorption Phase


Lab RGM ApparatusLab RGM Apparatus


Quartz Denuder AssemblyQuartz Denuder Assembly


Model 1130Model 1130Denuder & Denuder & Pump ModulePump Module


Preliminary Results - TorontoPreliminary Results - Toronto RGM Comparison: SN:001, SN:002

May-23 12:00 May-24 00:00 May-24 12:00 May-25 00:00 May-25 12:00 May-26 00:00 May-26 12:00

1998

0

10

20

30

40

50

60

RG

M (

pg

/m3

)

RGM SN:001 (y)

RGM SN:002 (x)

SuccessiveDesorption (Blank Test)

Denuder Clean

Operation

Outdoor Air(Sampling through long inlet manifold)

Indoor Airy = 1.0595x - 0.5374

R2 = 0.9959


Preliminary Results - TorontoPreliminary Results - TorontoElemental Mercury: SN:001 & SN:002

0

2

4

6

8

10

12

14

16

18

May-23 12:00 May-24 00:00 May-24 12:00 May-25 00:00 May-25 12:00 May-26 00:00 May-26 12:00

Date

Hg0 (

ng

/m3 )

Hg0 SN:001Hg0 SN:002

Outdoor Air

Indoor Air


Lab Testing: Frontier GeosciencesLab Testing: Frontier Geosciences


Seattle RGM DataSeattle RGM DataAmbient Air - Downtown SeattleAmbient Air - Downtown SeattleAmbient Air Hg(0) and RGM in Downtown Seattle

0

2

4

6

8

10

12

:30

00

:30

12

:30

00

:30

12

:30

00

:30

12

:30

00

:30

12

:30

00

:30

12

:30

00

:30

12

:30

00

:30

12

:30

00

:30

12

:30

00

:30

12

:30

August 22-31, 1998

Hg

(0)

(ng

/m3)

0

50

100

150

200

250

300

350

RG

M (

pg

/m3)

Hg(0) Tek-043 RGM Tek-043

Courtesy: Frontier GeosciencesCourtesy: Frontier Geosciences


Mercury Levels - Rural MichiganMercury Levels - Rural Michigan

0

5

10

15

20

25

30

35

21:1

0

23:1

0

01:1

0

03:1

0

05:1

0

07:1

0

09:1

0

11:1

0

13:1

0

15:1

0

17:1

0

19:1

0

21:1

0

23:1

0

02:4

0

04:4

0

06:4

0

08:4

0

10:4

0

12:4

0

14:4

0

16:4

0

18:4

0

Time of Day (EDT)

RG

M (

pg

/m 3 )

.

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Hg

(0)

(ng

/m 3 )

.

Hg(II)Hg(0)

Dew Rain

27-Aug-98 29-Aug-9828-Aug-98

Courtesy: UMAQLCourtesy: UMAQL


Summary - RGMSummary - RGM A quartz annular denuder coated with KCl A quartz annular denuder coated with KCl

quantitatively collects HgClquantitatively collects HgCl22 but does not retain but does not retain

HgHg0.0.

HgClHgCl22 collected on a denuder is thermally collected on a denuder is thermally

desorbed as Hgdesorbed as Hg0.0.

The automated instrument that uses this denuder The automated instrument that uses this denuder technology measures RGM concentrations down technology measures RGM concentrations down to 1 pg/mto 1 pg/m33..

Denuder lasts 1 - 2 weeks between recoatings.Denuder lasts 1 - 2 weeks between recoatings.

Part 2: Part 2: Particulate Mercury Particulate Mercury

MonitoringMonitoring


Why Bother Measuring TPM ?Why Bother Measuring TPM ?

Particulate bound mercury (Particulate bound mercury (TPMTPM / / HgHgPP) is ) is created directly by some industrial created directly by some industrial processes and also formed downwind of processes and also formed downwind of sources by the combination of mercury sources by the combination of mercury with existing particulates.with existing particulates.

TPMTPM is removed rapidly via wet and dry is removed rapidly via wet and dry deposition.deposition.


Particulate Mercury: TPMParticulate Mercury: TPMConsists of various compounds of mercury Consists of various compounds of mercury

bound onto particles.bound onto particles.Size range: Generally < 3 um.Size range: Generally < 3 um.Usually only a few percent of total mercury Usually only a few percent of total mercury

present in the atmosphere.present in the atmosphere.Short range: deposits relatively close to the Short range: deposits relatively close to the

source of emission.source of emission.


Difficulties Measuring TPMDifficulties Measuring TPMMethod must be 1-2 orders of magnitude Method must be 1-2 orders of magnitude

more sensitive than total mercury more sensitive than total mercury methods.methods.

Must reject much larger Must reject much larger elementalelemental component.component.

Method must exclude Method must exclude reactive gaseous reactive gaseous mercury, however, normal particulate mercury, however, normal particulate filters have problems in that they retain filters have problems in that they retain RGMRGM..


Model 1135 - Principles of OperationModel 1135 - Principles of Operation

Sampling PhaseSampling Phase Quartz, regenerable particulate filter (Quartz, regenerable particulate filter (RPFRPF) )

captures fine fraction (captures fine fraction (< 2.5 um< 2.5 um) particulates ) particulates after air has passed through impactor and after air has passed through impactor and denuderdenuder

Desorption/Analysis PhaseDesorption/Analysis Phase Zero air used as carrierZero air used as carrier Downstream Downstream pyrolyserpyrolyser is activated first is activated first RPF is heated to desorb captured particulatesRPF is heated to desorb captured particulates


Model 1135 – Particulate Mercury MonitorModel 1135 – Particulate Mercury Monitor

Unit stacks on top of Model Unit stacks on top of Model 11301130

Allows simultaneous deter-Allows simultaneous deter-mination of Hgmination of Hg00, RGM and , RGM and HgPHgP

Detection limit ~ 1 pg/mDetection limit ~ 1 pg/m33


Restrictor(100 ml/min)

MFM-1

CNCNO

ParticulateFilterPacks

Back PressureRegulator

BufferTank

ZeroScrubber

V2

500

75 35

Fan

CaseHeater

Zero Air (to Denuder Module)

Control & StatusSignals

ZeroScrubber(1st stage)

INLET

AirInlet

Vent

Heater &Temperature

SensorLeads

ZeroInlet

SampleInlet

PUMP MODULE

DENUDERMODULE

Model 2537AANALYZER

SamplePump

Control Cable

(Heated)

HEATED LINE

Interchangeable inlets: Impactor for ambient air or'Tee' piece for manifold

V1

50

MFM

CONTROLLER

ZeroOut

SampleIn

DenuderModuleControl

cable

NC C

NO

ZEROAIR

SAMPLE

600 40600

OvenCooling Fan

FritFilter

Wool

Dimples

QuartzChips

Pyrolyzer

ParticulateFilter

Teflon Union (90º)Tail

QuartzWool

OvenExhaust

CaseExhaust

Fan

SampleLine

CaseHeater

PARTICULATEMODULE

OvenExhaust

CaseExhaust

ControlConnector

ControlCable

GL14-GL18 Union

Thermal Safety Switch

Model 1135

Model 1130

Model 1130

Model 1130

Model 1130Model 1130& Model 1135 & Model 1135

Flow PathFlow Path


Ambient Air SpeciationAmbient Air Speciation

Mercury Species: Hg°, TPM & RGM St.Anicet (Quebec)

0.0

1.0

2.0

Jan-26 Jan-27 Jan-28 Jan-29 Jan-30 Jan-31 Feb-01 Feb-02

Ele

me

nta

l Me

rcu

ry -

ng

/m³

.

0

100

200

300

400

RG

M &

TP

M -

pg

/m³

.

Elemental Mercury - Hg°

Total Particulate Mercury - TPM

Reactive Gaseous Mercury - RGM

Model 1130 & Model 1135Model 1130 & Model 1135

Model 1130 - Reactive Gaseous Mercury (RGM)

Model 1135 - Total Particulate Mercury (TPM)

Model 2537A - Elemental Mercury (Hg0)

Model 1130 - Reactive Gaseous Mercury (RGM)

Model 1135 - Total Particulate Mercury (TPM)

Model 2537A - Elemental Mercury (Hg0)


Conclusions - HgPConclusions - HgP

A quartz RPF quantitatively collects particulate A quartz RPF quantitatively collects particulate mercury but does not retain Hgmercury but does not retain Hg00

HgP collected on a denuder is thermally HgP collected on a denuder is thermally desorbed and converted to Hgdesorbed and converted to Hg00 in the pyrolyzer in the pyrolyzer

Carbon based particulate matter on the filter is Carbon based particulate matter on the filter is oxidized to COoxidized to CO22 during desorption cycle during desorption cycle

Filter is usable for 1 – 2 weeks before requiring Filter is usable for 1 – 2 weeks before requiring restuffingrestuffing

tekran ® automated mercury speciation f.h. schaedlich 1, robert k. stevens 2, d.r. schneeberger 2,...

Documents

reactive mercury

classes of mercury

mercury analyzer slide

hg mining

internal hg

ambient air slide

atmospheric hg loadings

thermal power plants