availability of toxic heavy elements

8/3/2019 Availability of Toxic Heavy Elements

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S T U D I E S O F T H E A V A I L A B IL I T Y O F T O X I C H E A V Y E L E M E N T S I NS O I L S A N D S E D I M E N T S I N T H E V I C I N I T Y O F A L E A D S M E L T I N G

S I T E (G E R M A N Y )

D . W . Z A C H M A N N a nd R . B L O C KDe pa rtm ent of Geosciences, Technical U niversity o f Braunschweig, Pockelsstr . 4 , 381 06Braunschweig, FRG(Rec e ived 19 No vem ber , 1992; accep ted in f ina l fo rm 26 No vem ber , 1993)

A b s t r a c t . T h e l e ad sm e l t i n g s i te n ea r C l au s t h a l -Z e l le r f e l d ( Ha rz Mo u n t a in s , Ge rm an y ) w as i n o p e ra -t ion for 700 years . A s a resu l t o f t h i s l ong opera t ing t ime, the so i l and s t ream sed iment s in the v i c in i tyo f t h e s i t e a r e h i g h l y co n t am i n a t ed d u e t o a i rb o rn e p o l lu t i o n an d d u m p i n g o f s lag s . Th e k n o w l ed g e o fb u l k c o n cen t r a t io n s d o es n o t g i v e su f f ic i en t i n fo rm a t io n fo r an e s t im a t e o f t h e h aza rd p o t en t i a l s to r edin the con tamin a ted m ater i a l s . Therefo re , as a f i r s t s t ep , t he e l eme nt spec ia t ion in the th ree sam plepop ula t ions w as de te rmined . A s the ex t rac t ab i l i t y ( ava i l ab i l i t y ) o f t he spe c ia t ions var i es s ign i f i can t lyfor t he d i f fe ren t e l ement s , a secon d s t ep w as used to t es t fo r t he ava i l ab i li t y . Th e inve s t iga t ions ont h e av a i l ab i l it i e s y i e l d a v e ry h i g h h aza rd p o t en t i a l f o r l e ad , f o ll o w ed b y Cu an d Z n .

1. I n t r oduc t i o nD u e t o i n d u s t r i a l a c t i v i ti e s s i n c e a n c i e n t t im e s , m a n y s o il s a n d s e d i m e n t s i n M i d d l eE u r o p e a r e h i g l y p o l l u t e d b y h e a v y e l e m e n t s . E x t r e m e l y h i g h c o n t a m i n a t io n s o c c u ri n t h e v i c i n i t y o f m i n i n g a n d s m e l t i n g si te s . T h e m i n i n g i n d u s t r y h a s b e e n a c t i v e int h e H a r z M o u n t a i n s ( G e r m a n y ) f o r m o r e t h an 1 0 0 0 y ea r s. D u e t o t h is l o n g p e r i o d o fm i n i n g a n d s m e l t i n g , v a s t a re a s o f t h e H a r z M o u n t a i n s a re h i g h l y p o l lu t e d a n d s h o wc o n c e n t r a t i o n s , e s p e c i a l l y o f le a d ( N O W A K a n d P r e u l , 1 9 7 1 ), wh i c h s i g n if i c a n tl ye x c e e d t h e t o l e r a b l e l i m i t s a s d e f i n e d b y r e c e n t j u r i s d i c t i o n i n W e s t e r n E u r o p e( H e i n a n d S c h w e d t , 1 9 9 1 ; Bu n d e s g e s e t z b l a t t , 1 99 2). T h e s e l i m i t s a r e ( m g / k g d r yso i l subs tan ce) : Pb - 100 ; C u - 60 ; Z n - 200 ; As - 20 .

T h e d e f i n i t i o n o f t o l e r a b l e l im i t s c o n c e r n s e x t r a c ta b l e b u l k c o n c e n t r a t i o n s o fh e a v y e l e m e n t s i n s oi ls . T w o b a s i c p r o c e d u r e s e x i st f o r d e t e r m i n i n g t h e s e c o n c e n -t r a ti o n s . O n e p r o c e d u r e a n a l y z e s b u l k c o n c e n t r a t i o n s a ft e r d i g e s t i o n o f t h e s o il sa n d s e d i m e n t s w i t h s t r o n g a c i d s ( e. g . a q u a r e g ia ; p r o c e d u r e s ta n d a r d i z e d b y D I N3 8 4 1 4 - 7 ; c f. A p p e n d i x : A n a l y t i c a l p r o c e d u r e s ). G e n e r a ll y , t h is p r o c e d u r e le a c h e sh e a v y e l e m e n t a m o u n t s f r o m t h e s o il s a n d s e d i m e n t s , i n p e r c e n ta g e s w h i c h s ig n if -i c a n t l y e x c e e d t h e i r a v a i la b i l it y i n t h e i r n a tu r a l e n v i r o n m e n t . H o we v e r , o n l y t h ea v a i l a b l e c o n c e n t r a t i o n s a r e i m p o r t a n t fo r a p o l l u t i o n h a z a r d p r o g n o s i s .

A s e c o n d p r o c e d u r e m e a s u r e s t h e c o n c e n t r a ti o n s i n a n e l u t io n o f w a t e r ( D I N 3 84 1 4 - 4 ; c f . A p p e n d i x ) . T h e c o n c e n t r a t i o n s r e s u l ti n g f r o m t h i s p r o c e d u r e a re t o os m a l l t o b e u s e f u l i n h a z a r d p r o g n o s e s .

A n e s t i m a t e o f t h e a v a i l a b l e a m o u n t s ( e as il y e x t ra c t a b l e b y n a t u r a l p r o c e s s e s) o fh e a v y e l e m e n t s i n s o i l s a n d s e d i m e n t s c a n b e o b t a i n e d f i rs t b y a d e t a i le d d e f i n i ti o n o ft h e i r b o n d i n g f o r m s . I n t h e l a s t s e v e r a l y e a r s, p r o c e d u r e s h a v e b e e n p r o p o s e d , wh i c hWater , A ir and So i l Pol lu t ion 7 8 : 3 1 7 - 3 3 4 , 1 9 9 4 .@ 1994 K luw er Ac ade m ic Publishers . Printed in the Netherlands.


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31 8 D.W. ZACHMANN AND R. BLOCKs h o u l d a l l o w t h e b u l k o f e l e m e n t c o n c e n t r a ti o n s t o b e d i s c r i m i n a t e d i n t o d i f fe r e n tb o n d i n g f o r m s . T h e s e p r o c e d u r e s c a n b e s u m m a r i z e d a s ' s e q u e n t i a l e l u t io n ' ( e. g.Tess i e r e t a l . , 1 9 7 9 ; F 6 r s t n e r a n d Ca l m a n o , 1 9 8 2 ; F 6 r s t n e r , 1 9 8 7 ; G u n n e t a l . ,1 9 8 8 ). T h e p r o c e d u r e s a re b a s e d o n t h e s u b s e q u e n t e l u t io n b y a s e ri es o f s o l u ti o n s ,e a c h o f w h i c h d i g e s ts a s p e c if ic b o n d i n g f o r m , t h u s l ib e r a ti n g t h e p e r c e n t a g e o fe l e m e n t s f ix e d in t h i s b o n d i n g f o r m .

O f s p e c i a l i n t e r e s t a r e b o n d i n g f o r m s o f l o w s t a b i l i t y , w h i c h s h o w a h i g hp o l l u t i o n p o t e n t i a l fo r t h e e n v i r o n m e n t . S u c h b o n d i n g f o r m s a re :

a ) adsorp t i on ,b ) m ine ra l i za t i ons o f l ow o r i n t e rmedia t e s tab i li ty i n na tu ra l env i ron m ent s , e .g .

l i m o n i t e ( F e O O H ) .A s n a t u r a l s u b s t a n c e m a y b e c o m p o s e d p a r ti a ll y f r o m p o o r l y d e f i n e d s u b s t a n c e s(am orp ho us , tr ans i t iona l , m e ta s t ab le ) , t he re su lt s o f t he sepa ra t i on p roced ure s a res tr ic tl y o p e r a t i o n a l ( L o r i n g a n d Ra n t a l a, 1 9 9 2 ) a n d s h o u l d b e c o n s i d e r e d a t th em o s t a s a n a p p r o x i m a t i o n o f t h e ' tr u e ' m i n e r a l o g i c a l c o m p o s i t i o n o f th e s a m p l e s .A p p l i e d t o m i x t u r e s o f p u r e s u b s t a n c e s (i .e . c a r b o n a t e s, F e - M n - o x i d e s , s u l f id e s ,e tc . ) t h e s e p a r a t i o n p r o c e d u r e d e s c r i b e d b y J a k o b e t a l . (1990) a l l ows d i f fe ren t i -a t io n s i n t o r e a s o n a b l e m i n e r a l o g i c a l p h a s e s . A s d e m o n s t r a t e d f o r t h e e x a m p l e o ft h e F e - M n - o x i d e s ( F ig . 1 ) t h is J a k o b ' s m e t h o d al s o h o l d s fo r t h e s o il s a n d s t r e a ms e d i m e n t s i n v e s t i g a t e d i n t h is s tu d y . Co u p l e d w i th c a r e f u l o b s e r v a t i o n a n d c o n -s ide ra t i on o f i t s l im i t a ti ons , t he seq uen t i a l e l u t i on p roce dur e is a va luab l e t oo l fo rt h e d i s c r i m i n a t i o n o f b o n d i n g f o r m s , a n d c a n g i v e a b e t t e r u n d e r s t a n d i n g o f t h eava i l ab i li t y o f t ox i c e l em ent s .

H o w e v e r , i t s h o u l d b e k e p t i n m i n d , th a t d i ff e r e n t e l e m e n t s in t h e v e r y s a m eb o n d i n g f o r m s h o w d i f f e re n t s o lu b i li ti es . T h e r e f o r e , th e d e f in i ti o n o f b o n d i n g f o r m sb y t h e s e q u e n t i a l e lu t i o n p r o c e d u r e a l o n e d o e s n o t g i v e s u f f ic i en t i n f o r m a t i o n o nthe ava i l ab i li ty o f e l em ent s .T h e e s t i m a t e o f a d i r e c t a n d s h o r t - te r m h a z a r d b y h e a v y e l e m e n t s h a s t o t a k e i n t oc o n s i d e r a t i o n t h e p r o p o r t i o n s o f e a s il y e x t r a c ta b l e c h e m i c a l fo r m s ( s p e c ia t io n s ) i nt h e s o i l s . I n o r d e r t o q u a n t i f y t h e s e p r o p o r t i o n s , a b u l k e l u t i o n p r o c e d u r e w a sa p p l ie d . T h e m e t h o d w a s o r i g in a l ly d e v e l o p e d to d e f i n e t h e c o n c e n t r a t i o n s o f p l a n tava i l ab l e ca t i ons i n so i ls (DIN 19 684 -8 ; c f . App endix ) , i .e . t he gene ra l l y ea s i l ya v a i la b l e c a t io n s i n s o i ls . T h e m e t h o d is b a s e d o n t h e p e r c o l a ti o n w i t h a Ba - c h l o r i d eso lu t i on (pH = 7) . I t mea sure s t he ava i l ab i l it y o f t he e l eme nt s wi thou t de f in ing t hes p e c if i c b o n d i n g f o r m s . T h e c o m b i n a t i o n o f t h e re s u lt s o f b o t h e l u t i o n p r o c e d u r e sw i l l g i v e a m o r e r e a l is ti c e s t i m a t e o f th e h a z a r d p o t e n t i a l o f s o m e h e a v y e l e m e n t si n d i f f e r e n t s a m p l e p o p u l a t io n s .T h i s s t u d y t a k e s i n t o a c c o u n t o n l y l o n g - t e r m ' n o r m a l ' e n v i r o n m e n t a l p r o c e s s e s ,i .e . l e a c h i n g o f t o x i c e l e m e n t s b y p o r e s o l u t i o n s f r o m r o c k s a n d s o i ls . T h e c o n -s e q u e n c e s o f c h a n g e s o f s o i l p H d u e t o a c i d p r e c ip i t a ti o n ar e n o t c o n s i d e r e d (e .g .c o r r o s i o n a n d d i s s o l u t i o n o f t r a n s it io n e l e m e n t c a rb o n a t es ) .


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S T U D I E S O F T H E A V A I L A B I L I T Y O F T O X I C H E A V Y E L E M E N T S 319

E:._mt -O

r -0J0t-"0O

1 0 09 0 -8 0 -7 0 -6 0 -

4 0 43 0 -2 0 -1 0 -

0

A I

/ ' & ' " - , i . , . " F e

1 2o Fe ( forest soi ls )

- ~ - - F e ( s tr e am s e d .)Fig. 1.

3 4 5 6steps o f seq uen tial elutionM n ( forest so i ls ) ~ AI ( forest soi ls )

- -~k-- M n (stream sed.)Percentages of Fe- , M n-, and Al-concentrations eleasedduring seq. el.

2 . A na ly t i ca l procedu resT h e e l u t io n p ro c e d u re u s e d h e r e fo l lo w s t h e m e t h o d a s d e s c r ib e d b y J a k o b e t a l .(1 99 0 ). T h e m e t h o d i s b a s e d o n t h e e v a l u a ti o n o f d i ff e r e n t e l u t io n me t h o d s (T e s si e re t a l . , 1979 ; F6 rs tn e r and Ca lm ano , 1982 ; F6 rs tne r , 1987 ; G unn e t a l . , 1988). Theapp l i ed e lu t ion p roce du re was ve r i f ied in d i f fe ren t l abo ra to r ie s on indus t r ia l andn a t u r a ll y o c c u r r i n g s u b s t a n c e s w i t h g o o d c o i n c i d e n c e o f t h e r e s ul ts .

T h e a p p l i e d e l u ti o n p ro c e d u re d e f i n e s t h e fo l lo w i n g b o n d i n g fo rm s o f e l e me n t s(1. - 6 . : elu t io n steps):

1. Ex cha nge ab le ca t ions : adso rp t ion to so i l m ine ra l s (e .g . c l ay mine ra l s , ca rbon-ates, etc.) .

2 . Ca rbona te hos t ed ca t ions : i som orph ica l subs t it u t ion o f ca rbona te hos t ed ca t ionsby t race ca t ions o r so l id so lu t ion o f ca rbona te fo rming ca t ions (e .g . Zn ind o l o mi t e ) .

3 . E as i ly reduc ib l e phase : ca t ions subs t i t u t ed in to am orph ous ox ide -hydro x ide -p h a s e s (M n , Fe , A I ).4 . M ode ra t e ly redu c ib l e phase : ca t ions subs t i tu t ed in to c rys t a l li ne ox ide -hydro x ides

(Fe , A1, M n).5 . Su l f id i c and o rgan ic phase : su l fide fo rm ing e l emen t s and e l emen t s w i th a h igh

aff in i ty to organic so i l substances .


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320 D . W . Z A C H M A N N A N D R . B L O C K

TABLE IProcedure o f sequential elution (abbreviations: amrn.ac. - amm o-nium acetate; Na-ac. - sodium acetate; am m . cl. - amm oniumchloride; sample weight: 1 g)

elution solution/ pH q u a n - time ofstep co nc en tr , t ity extract.(ph as e) (mol/1) (n'd) (h)

remarks

1 a m m . a c . / ( 1 ) 7 2 0 2 12 Na-ac./(1) 5 20 5 13 hydroxyl-

am m.cl./(0.1) 2 100 12 14 amm.oxalate-

ox. acid/(0.2) 3 100 24 15 a) H202 2 30 2 2

b) am m .ac./(1) 7 100 12 26 aqua regia


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STUDIES OF THE AVAILABILITY OF TOXIC HEAVY ELEMENTS 321BaC12-so lu tion . Th e p roced ure wa s therefore mo di f i ed by r e duc in g the perco la t ionra te to 0 .2 mL/m in . (Gol l , 1990; M eiw es e t a l . , 1984).

T he ques t i on i s how f a r concen tr a ti ons o f P b , Z n , C u , an d C d e l u t ed by t heBaC12-solution (def ined here as eas i ly avai lable) f it con cen trat ions eluted by s ing lee lu t ion s t eps o r sum s o f e lu t ion s t eps o f the sequ ent ia l ex t r ac tion , o r wh ethe r theyfit at all.

3. Pre l imina ry inves t igat ionsIn add i t ion to the e lements bound by adsorp t ion (phase 1) , some of the heavye l emen t s bound by t he r educ i b l e phas es ( 3 and 4 ) mi gh t be ea s i l y ava i l ab l e .T he bu l k compos i t i on o f t he r educ i b l e phas es i s p r edomi na t ed by F e - and M n-oxideh ydrox ides . Therefore , the r e lease (i.e . deco m pos i t ion of the ox ides ) o f Feand M n dur ing the sequent ia l e lu t ion was sc ru t in ized (Fig . 1 ).

As dem ons t r a t ed by t he r mo dyna mi c ca lcu l a ti ons in t he s y st em: E h , pH , F e , M n ,02 , O H - ( e .g . B a l l e t a l . , 1987), und er r edu c ing condi t ions the r eac t ion beg ins w i ththe deco m pos i t ion of the Mn -phase . Inves t iga tions on 10 st r eam sed iments (B lockand Za chm ann , 1991) , and 17 so i l s amples (Lotze , 1992) dem ons t ra te tha t M nis ex t rac ted m ain ly dur ing e lu t ion s t ep 3 , whe reas Fe fo l low s in s t ep 4 (F ig . 1 ).The refore , fo r s impl i fi ca t ion , the eas i ly r educ ib le phase ( s t ep 3) wi l l be def inedin th i s t ex t as Mn-oxide phase , and the modera te ly r educ ib le phase ( s t ep 4) asF e - ox i de phas e .

T he m i ne r a l og i ca l phas e ana l y se s wh i ch we r e pe r f o r med by B l ock and Z ac h -m ann (op . c i t. ) d i sp lay a l ack of Mn-m inera l i za tions desp i te r e la tive ly h igh am ountsin so m e o f the sam ples ( c f. T ab le I I) . Th is ind ica tes tha t the eas i ly r educ ib le phasei s p r edom i na t ed by ( X- r ay ) amo r phous M n phas es . Howeve r , t he phas e ana l y se sd i sp lay o x id ic -hy drox id ic Fe m inera l iza t ions ( e .g . hem at i te , l imoni te ). Th i s ind i -ca t e s t he decom pos i t i on o f co m poun ds o f h i ghe r c r y st a ll in i ty du r i ng e l u t ion s tep4 . In add i t ion , the ana lyses o f the so i l s amples a l so show a s ign i fi can t r e lease o f A1du r ing elut ion s tep 4 (Fig. 1).

4 . C om p ar i s on o f i n ve st iga t ion s o f t h e b on d i n g f or ms o f h e avy e l e me n t s i ndi f ferent sample po pulat ions

T he s equen t ia l e l u t ion p r ocedu r e was app l ied f o r t he de t e r mi na t ion o f t he bon d i ngforms of hea vy e lem ents in fo res t so il s (para-brown ear th , so il pH 3 .8-4 .6) , s t reamsedim ents , and s lags . Al l s am ples w ere t aken in the v ic in i ty o f the B le ih ti tt e ( lead)smel t ing s i t e near C laus tha l -Ze l l e r fe ld (Harz Mounta ins , Germany; F ig . 2 ) . Thesm el t ing s i te w as in opera t ion for 700 year s . Therefore , a ll a reas and m ater ia l s int he v i c i n it y a r e h i gh l y po l lu t ed by heavy e l emen t s . T h i s i s s hown by t he map o flead d is t r ibut ion in fores t soi ls in the Bleiht i tte area (Fig. 3) .

T he mi ne r a l og i ca l com pos i t ion and t he bu l k concen t r a t ions o f heavy e l emen t sand m ain e le m ents o f the an a lyzed m ater ia l s a re li s ted in Tables 2 , 3 , and 4 . The


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322 D.W. ZACHMANNAND R. BLOCK

TABLE IIMean concentrations of some main elements in forest soils, highlycontaminated stream sediments, and slags (weight-%)

materialsforest forest stream slags

element soils (lc) soils (hc) sediments (n = 2)Fe 1.36 -t- 0.28 2.94 4- 0.42 3.30 4- 1.10 12 .9Mn 0.04 4- 0.03 0.02 4- 0.01 0.40 4- 0.24 0.83Ca 0.02 4- 0. 01 0.02 4- 0.01 1.31 4- 0.87 0.59Mg 0.114-0.04 0.124-0.05 0.344-0.08 0.41A1 1.08 4- 0.01 1.20 4- 0.27 0.72 4- 0.33 0.47

forest soils:- lc: background forest soils; low concentrations of toxic elements- hc: contaminated forest soils; high concentrations of toxic elements

TABLE IIIMineralogical and chemical composition (bulk analyses) of the investigat-ed forest soils in comparison to tolerable values

sample mineral, heavy elementsNr. compos. Zn Pb Cu Cd Ni As Se1100/12 H, Q, M 100 1530 17 7 15 7 1.1

/20 Q, H, M 90 248 12 6 21 3 0.9/55 Q, M, Fs 51 92 13 5 32 5 0.5

1200/9 H, Q, M 110 31160 135 7 22 26 2.5/17 H, Q, M 57 5690 27 8 33 8 0.9/25 Q, M, H 72 3400 24 6 21 3 0.7/55 Q, M, Fs 44 628 6 6 14 3 0.4

1400/8 H, Q, M 95 1970 60 7 20 6 0.3/15 H, Q, M 92 1730 53 7 19 6 0.2/25 Q, M, H 71 1070 39 6 20 4 0.1/40 Q, M, Fs 47 463 10 4 20 4 0.5

tolerable values inculture soils 300 100 100 3 50 20 10Kloke, 1980

Abbreviations: H - humic substances, Q - quartz, M - muscovite, Fs -feldspar;Concentrations in ppm (#g/g), rounded values; .../12: sampling from depthof 12 cm


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STU DIES OF TI - IE AVAILABILITY OF TOX IC HEAVY ELEMENTS 3 2 3

B a d

, , ~ 8 0 1 " J 1 ~_ ~ J ,=' } " 7" ~ L s n g e l e - L _,I' :. ' . . $ / i n v e s t g a t o n

I = ~ 1 7 6 q l l.::.: ~ = _ o , . . . , . , .i = l g o

F i g . 2 . S i t u a t i o n o f i n v e s t i g a t i o n a r e a

s o i ls w e r e s a m p l e d a t d i f f e r e n t d e p t h s . T h e d i s t r i b u t io n o f e l e m e n t s i n r e l a ti o nt o t h e c o r r e s p o n d i n g b u l k c o n c e n t r a t i o n s is d i s p la y e d f o r s o m e o f t h e e l e m e n t si n F i g . 4 a a n d F i g . 4 b . A s s h o w n b y F i g . 4 a, b t h e d if f e re n t s a m p l e p o p u l a t i o n sa re c h a r a c t e r iz e d b y d i f fe r e n t p r e d o m i n a n c e s o f e l e m e n t s p e c ia t io n . F o r i n s ta n c e ,i n t h e f o r e s t s o i l s Z n i s b o u n d t o p h a s e 4 ( F e - o x . - h y d r o x . ) a n d p h a s e 6 ( r e s i d u a lp h a s e ) . I n t h e s l a g s , Z n i s f i x e d p r e d o m i n a n t l y t o t h e s u l f id i c (5 ) a n d s i li c at e p h a s e s( 6) . T h e Z n c o n c e n t r a t io n s i n t h e s t r e a m s e d i m e n t s a r e c o n t r o l le d b y t h e c a r b o n a t e( 2 ) a n d e a s i l y r e d u c i b l e ( 3 ) p h a s e s .

T h e s e f i n d i n g s i n d i c a t e v e r y d i f f e r e n t a v a i la b i li ti e s o f t h e h e a v y e l e m e n t s w i t ha s o m e t i m e s i n c r e a s e d h a z a r d p o t e n t i a l f o r s u b s t a n c e s w i t h c o m p a r a b l e l o w c o n -c e n t r a t i o n s .


8/18

324 O . W . Z A C H M A N N A N D R . B L O C K

3 5 8 9. 20 0 3 5 8 9 .4 0 0 3 ~1 1.0 00 ~ l m J l C O 3 5 1 1 0 . 0 0 0 ~ 9 0 2 0 0

< 1 0 0 0 E ~ ". 2 0 0 0 ~ ~

3000 c .oo N4 0 0 0 , ~s 00o ~ .~ '

6 0 0 0 " ~ 3 :7 0 0 0 ~ P800O o9000 cO> 9 0 0 0 o

2 6 7 s a m p l e s1 1 0 0 , 1 2 0 0 , 1 4 0 0 :f o r e s t s o i ls a m p l i n g p o i n t ss a m p l i n g d e p t h :

A - B - h o r i z o nh v0 5 0 0 m

F i g . 3 . P b - d i s t r i b u t i o n i n f o r e s t s o i ls n e a r t h e l e a d s m e l t i n g s i t e


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ST UD IE S OF T H E AVAIL ABILIT Y OF T OXIC HE AVY E L E ME NT S 325

10090-: 80-

70-60-

~ 5 0 -4 0 -

[ 30 -2 ( 1 *1 0 -

0 + - - - -s a m p l e n u m b e r

f o r e s t s o i l s

! I

111= 9

IGO 116

s l a g s s t r e a m s e d i m e n t s

ilO 11 )9o 14 3 / o 11122o I M o 8 0 1 8 0 ~1 1 2 1I m O 8 1 7 0 ( buk rPm"l1 ^

3

s a t n pt e n u m b e r

f o r e s t s o i l s s l a p s

1 1 0 0 1 2 0 0 1 4 G 0 ~ 1 ~ t : ] ~ ~a, l12 I tO 11) 151530 31 l eo 1730 5710 ~eO 10300 10380

adsorptive ph ase ~ carbonatic ph.Fe-ox.-hydm x. ph. ~ sulfidic phase

s t r e a m s e d i m e n t s

; ~ ( = , ~m p~ epm - e ra )14130 ( bu l k r

Mn -ox.-hydrox. ph.residual ph.

F i g . 4 . ( a ) S e q u e n t i a l e l u t i o n - d i s t r ib u t i o n o f e l e m e n t sp e c i a t i o n ( Z n , P b )


10/18

326 13. W. ZACHMA NN AN D R. BLOC K

I ( 9 09 0 -

t-O 70-60-

i~ 40"

2 0 "10"

f o r e s t s o i l s s l a g s

umberi ; l I 1 0

s t r e a m s e d i m e n t s

; 2 5 1 2I f3 2 8 2 1 4 6 7 4

S O lt s am (=mmam ~=m~.l eo ~ ( b U k 9

IO 09 0 ~8 0 -

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~= 4o-

10-

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i i i i i i i i i ! i

1 2 I ) 1 07 21 e 1 1 1 7

adsorptive ph as e i carbo nattc ph.Fe-ox.-hydrox. ph. 1 7 ~ sul f ldic pha se

1 0 1 11 n a4 4 ~ ' 4 7

Mn -ox.-hydrox . ph.residual ph.

( la J k c m e m n d Q n

F i g . 4. ( b ) S e q u e n t i a l e l u t i o n - d i s t ri b u t io n o f e le m e n t s p e c ia t i o n (C u , A s )


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STUDIES OF THE AVAILABILITYOF TOXIC HEAVYELEMENTS 327

TABLE IVM ineralogical com position and concentrations of h eavy elemen ts (bulk analy-ses; #g/g) of the investigated stream sediments and slags

sam ple mineral, heavy elementsNr. co m p o s. Zn Pb Cu Cd Ni As Sea) stream sedimentsIT 600 Q, Fs, M, K1 125 1310 51 5 17 5 0.7IT 512 Q, S, C,K, I 9850 10300 574 58 46 43 3.5IT 801 Q, O, C, K,I 9330 10380 680 37 35 37 0.5IT 805 Q, O, C,G,I 5167 14130 550 22 27 47 0.7b) slagsS1 Olivine 16 37 0 57 10 330 11 55 15 2.1$2 Olivine 1222 0 60 90 285 8 48 17 2.2

Abbreviations: Q - quartz, M - muscovite, O - olivine, C - cerussite, K -calcite, S - sphalerite, I - illite, Fs - feldspar, K1 - kao linite, G - galena.

5 . Resul t s

I n T a b l e V t h e P b c o n c e n t r a t i o n s e l u t e d b y B a C 1 2 a r e c o m p a r e d t o t h o s e e l u t e db y t h e s i n g l e s t e p s o f t h e s e q u e n t i a l e lu t i o n a n d t h e s u m s o f e l u t io n s t e p s ( 1 +3) , and (1 + 3 + 4 ). Th e Pb c onc en t r a t i on s e l u t ed by t he BaCI 2 so l u t i on f i t t hea m o u n t s r e l e a s e d f r o m t h e a d s o r p t i v e p h a s e ( 1 ) , a n d t h e t w o o x i d i c p h a s e s ( 3 , 4 ) .A c c o r d i n g l y , t h e l e a d c o n c e n t r a t i o n s b o u n d t o p h a s e s 1 , 3 , a n d 4 a r e c o n s i d e r e de a s i l y a v a i l a b le .

T h e m e a n o f P b r e l e a s e d f r o m p h a s e s 1, 3 , a n d 4 i s a b o u t 4 5 % o f th e to t a l P bc o n c e n t r a t i o n o f th e f o r e s t s o il s . A l l o w i n g f o r t h e v e r y h ig h t o t a l c o n c e n t r a t i o n o fP b i n th e f o r e s t s o i ls ( u p t o 5 % ; B l o c k , 1 9 9 2 ) , th e a r e a o f t h e f o r e s t so i ls h a s t o b ec o n s i d e r e d a s e n v i r o n m e n t a l ly h a z a r d o u s w i th a h ig h c o n t a m i n a ti o n p o t e n t ia l f o rp l a n t s a n d w a t e r ( o f. T a b l e 5 , la s t c o l u m n ) .

A c c o r d i n g t o D r ie s ( 1 9 8 7 ) , th e s u b s t i tu t io n o f F e a n d M n b y P b is r e s p o n s i b l ef o r l e a d c o n c e n t r a t i o n s i n M n - a n d F e - o x i d e s a n d - h y d r o x i d e s . H o w e v e r , d u e t ot h e v e r y d i f f e r e n t c r y s t a l r a d i i o f P b 2 + ( 1 3 3 p m ; T a b l e V I I ) a n d F e z + ( 7 5 p m ) a n dM n 2 + (8 1 p m ) , P b w i l l n o t s u b s t i t u t e F e a n d M n i n th e i r o x i d e s a n d h y d r o x i d e s . T h eg e n e r a l l y e a s y a v a i l a b i li t y i n d i c a te s t h e p r e d o m i n a n c e o f t h e a d s o r p t i v e b o n d i n go f le a d t o F e - M n - o x i d e - h y d r o x i d e ( cf . T a b l e V ) . T h e p e r c e n t a g e o f th e M n - o x i d ep h a s e ( e lu t io n p h a s e 3 ) re a c h e s o n l y 1 % o f t h e F e - o x i d e p h a s e . H o w e v e r , th ea m o u n t s o f le a d b o u n d t o th e M n - o x i d e p h a s e s o m e t i m e s e x c e e d t h os e b o u n d tot h e F e - o x i d e p h a s e . T h i s d e m o n s t r a te s t h e e x tr e m e i m p o r t a n c e o f t h e M n - o x i d ep h a s e ( X - r a y a m o r p h o u s ) f o r th e b o n d i n g o f h e a v y e l e m e n t s a s c o m p a r e d t o th eF e - o x i d e p h a s e.


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328 D.W. ZACHMANN AND R. BLOCK

TABLE VComparison between Pb elution by BaC12 and sequential elution from forest soils (in% of total concentration; relativestandard deviation of all elution procedures in therange of 2.1 - 4.4%; n = 3)

Spl. Nr. BaClz sequentialdution(%) steps(%) steps steps 1+3+4

1 2 3 4 5 6 1+3 1+3+4 in(%) (%) ~g/g1100/12 43 11 51 11 23 1 3 22 45 6901200/9 58 39 40 3 10 4 4 42 52 16200

/25 48 21 43 5 24 1 6 26 50 1700/55 45 21 53 - 13 3 10 21 34 210

1400/8 43 15 58 15 8 1 3 30 38 750/15 43 16 46 12 12 - 5 28 50 870/40 56 25 41 14 14 1 5 39 53 250

Because lead shows a high tendency to form chloride complexes (Ball e t a I . ,op cit.; Parkhurst e t a I . , 1980; Salomons and F6rstner, 1980), the BaC12 solutionmay extract higher amounts than the easily available concentrations (e.g. in elutionstep 4). However, even i f the amount of available lead considered is restricted tothe amounts obtained in phases 1 and 3 (20--40% of total lead), there are still veryhigh amounts of available lead stored in the contaminated area.

In Table VI the concentrations of Zn, Cu, and As eluted by the BaCI2 solution(easily available) are compared with those eluted in steps 1, 3, and 4 by thesequential elution. The comparison of the different elution procedures shows adistinct difference of the availability of Pb on the one hand, and Zn, Cu and As onthe other hand.

The bulk concentrations of Zn in the forest soils are small and the amountsbound to the adsorptive (1) and the easily reducible (3) phases are near ly negligible.As demonstrated by the BaC12 elution, the amounts of Zn eluted are also nearlynegligible. Therefore, they fit best the amounts bound in phases 1 and 3 (TableVI). Probably, the prevailing soil pH of about 4 in the investigated area severelylimits the fixation of Zn. The Zn amounts bound to the Fe-oxidic phase (4) werenot released by the BaCI2 solution. Due to the small amount of the total Zn andthe extremely small amounts of easily available Zn, under present conditions thecontaminated area is not considered as an environmental hazard with regard to Zn.

The radius of Zn2+ (88 pro) allows the i somorphous substitution of Fe as well asof Mn in crystal structures. Whereas Pb is easily available from both oxide phases(Mn, Fe), Zn is bound with a high stability only to the Fe-oxide phase. The stablefixation of Zn by the Fe-oxidic phase during the BaCI2 elution fits the observations


13/18

STUDIES OF THE AVAILABILITY OF TOXIC HEAVY ELEMENTS 329

TABLE VICom pari son o f elution of heavy metals from forest soils by BaC12and sequential elution (in % of total concentrations; relative stan-dard deviation of all elution procedures in the range of 2.1-4.4%;n = 3)

Ele m. Spl.N r./ BaC12 sequ. eluti on (%) availabl e ~de pt h (%) steps (#g/g)

1 1 ,3 1 , 3 , 4Zn

Cu

1100/12 4 - - 24 -1200/9 19 - 10 50 1 l

/25 3 - - 28 -/55 2 - - 34 -1400/8 3 - 1 24 1

/15 5 - 1 30 l/40 3 - 4 28 2

1100/1 2 7 - - 76 -1200/9 7 1 3 79 4

/55 20 2 13 73 11400/8 32 - 26 60 15

/15 7 - 2 61 1/40 4 - - 70 -

As

stepsl 1 , 3

1100/12 - 1 10 0.071200/9 . . . .1200/25 1 - 42 -1400/8 - - 18 -

/15 4 - - -/40 - 5 24 0.20

Calculated from bulk concentrations (c.f. Table IV) and percent-ages elu ted by steps: - Zn, Cu: ste ps 1 + 3; - As: step 1.

TABLE VIICrystal radii of cations considered in this study; data according to Shannon (1976); radiiin pm (10 -12 m); the ionic radii are given for sixfold coordination

cat ion Fe 3+ Fe 2+ Mn 3+ Mn 2+ Pb 2+ Zn 2+ Cu z+ As 3+ As 5+rad iu 69 75 72 81 133 88 87 72 60


14/18

330 D . W . Z A C H M A N N A N D R . B L O C Kr e p o r te d b y B r t im m e r e t a I . (1986) , acco rd ing to wh ich Z n i s re l eased on ly a f t e rd iges t ion o f t he ox ides . H owe ver , cons ide r ing the c rys t al rad i i it is no t qu i t e ev id en tw h y Z n s h o u l d n o t b e f i x e d in t h e M n -o x i d e p h a s e ( cf . C u ) . T h e v e ry s m a l l b u l kconc en t ra t ions o f Zn in t he so i ls o f t he i nves t iga t ed a rea do no t a l l ow a con c lus ivea n s w e r f o r t h e m o m e n t .

T h e r a d i u s o f C u i s s i m i la r t o th a t o f Fe a n d M n a n d m a y r e p l a ce b o t h i s o mo r -ph ica l ly i n l at t ices . S im i l a r t o Zn , t he adso rp t ive ly bo un d Cu pe rcen tag es (phaset ) a r e r el a ti v e ly s ma l l. H o w e v e r , t h e a mo u n t s o f C u b o u n d to t h e M n o x i d e p h a s ea re no t neg l ig ib l e (c f . Tab le VI) . A s dem ons t ra t ed by the B aC12-e lu t ion , th i s Cuperc en tag e is eas i ly ava i l ab le w i thou t d iges t ion o f t he M n-ox id i c phase . S im i l a r t oZ n a n d i n c o n t r a s t to t Pb , C u w a s fo u n d t o b e n o t e a s il y a v a il a bl e f r o m t h e Fe -o x i d ep h a s e .A c c o r d i n g to M c L a r e a n e t a l . (1983) , Cu i s no t eas i ly ava i lab l e f rom the ox idephases . H ow ever , t h i s s t a t em en t shou ld be re s t ri c t ed to t he Fe -o x ide phase .

D ue to t he ease o f vo la t il i za tion du r ing sme l t i ng p rocesses , h igh (bu lk ) amo un t so f A s s h o u l d b e e x p e c t e d i n t h e e n v i ro n m e n t o f t h e B l e i ht it te s me l t i n g s it e. T h eo c c u r r e n c e o f h i g h a m o u n t s o f A s i n th e B l e ih t it te a r e a a r e d o c u m e n t e d in t h es t ream sed im en t s . Ho wev er , t he vo la ti li za t ion o f As f ro m so i ls by m e thy la t ion is aw e l l k n o w n p ro c e s s (A n d re a e , 1 98 6 ; M c B r i d e e t a l . , 1978 ; Vah te r and M ara fan te ,1 9 8 8) a n d t h e r e fo r e, t h e p o t e n t ia l ly h i g h a m o u n t o f A s c a n n o l o n g e r b e fo u n d i nthe fore s t so i ls .Th e co ncen t ra t ions o f eas i ly ava i l ab le As (e lu t ion phase 1 ) a re neg l ig ib l e . Thec ry s ta l r a d ii o f A s 3 + a n d A s 5 + a l lo w t h e i s o m o rp h i c a l r e p la c e m e n t o f F e a n dM n i n t h e o x i d e p h a s e s . A c c o rd i n g to t h e s e c o n d i t io n s , A s i s b o u n d w i t h a h i g hs ta b il it y i n t h e M n -o x i d e p h a s e a n d e s p e c i a l l y 'i n th e F e -o x i d e p h a s e o f t h e s t r e a msed im en t s and s l ags (c f. F ig . 4a and 4b ) . F rom bo th phases i t i s no t ex t rac t ed by theB a C I2 s o l u ti o n . T h i s f i n d in g fi ts t h e w e l l k n o w n f a c t th a t Fe -A s c o m p o u n d s ma yshow a ve ry h igh s t ab il it y . Fo r i n s t ance , Fe (AsO 4) 9 2H 20 ( sko rod i te ) i s ex t rem elys t a b le a n d t h e r e fo r e p ro p o s e d a s a p o s s i b l e f o rm o f d e t o x ic a t i o n o f h a z a rd o u s A sc o m p o u n d s (H e i n is c h e t a l . , 1985).

6 . S u m m a ry a n d co n c lu s io n sT h e c o m p a r i s o n o f b o t h e l u ti o n m e t h o d s s h o w s a g o o d c o i n c i d e n c e o f t h e b u l kconc en t ra t ions (e spec i a l ly Pb ) e lu t ed by the BaCI2 so lu t ion and the conce n t ra t ionso f so m e bo nd ing fo rm s ex t rac t ed by the sequen t i a l e lu t ion (c f. Tab le V and V I) .

T h e c o mp a r i s o n o f t h e r e s u l t s o f b o t h p ro c e d u re s a l l o w s fo r a mo re p r e c i s ede f in i t i on o f t he e as i ly ava i lab l e bon d ing fo rm s in po l lu t e d so il s. Base d on th i ss tudy , t he re su l t s o f the se quen t i a l e lu t ion ma y be u sed w i th m ore s ign i f i cance fo rt h e p ro g n o s i s o f h a z a rd s i n t h e e n v i ro n me n t .H e a v y me t a l s f r o m t h e fo l l o w i n g b o n d i n g fo rms m a y b e g e n e ra ll y a v a il a b le i nn a t u r a l e n v i ro n m e n t s w i t h o u t c h a n g e o f t h e s o i l p H :

- a d s o rp t i v e b o n d i n g


15/18

STUDIES OF THE AVAILABILITYOF TOXIC HEAVY ELEMENTS 3 3 1

TABLE VIIIAvailability of Pb, Cu, Zn, and As from the single bondingforms (X = easily available)

elutionphase bonding form Pb Zn Cu As1 adsorptive X X X X2 Mn-ox.-hydrox. X X X3 Fe-ox.-hydrox. X

- b o n d i n g b y M n - a n d F e -o x i d e - h y d r o x i d e sH o w e v e r , t h e a v a i l a b il it y o f d i ff e r e n t e l e m e n t s in th e v e r y s a m e b o n d i n g f o r mv a r i e s s i g n i f ic a n t ly . G e n e r a l ly , a l l e l e m e n t s b o u n d t o t h e a d s o r p t i v e p h a s e ( 1 ) a ree a s i l y a v a i l a b l e . T h e p r o p o r t i o n s b o u n d t o t h e M n - ( 3 ) a n d F e - o x i d e ( 4 ) p h a s e ss h o w d i f f e r e n t s t a b i li ti e s . P b i s e a s il y a v a i l a b l e f r o m a ll th r e e p h a s e s ( 1 , 3 , 4 ) . Z na n d C u a r e f i x e d b y t h e F e - o x i d e p h a s e b u t n o t b y t h e M n - o x i d e p h a s e , w h e r e a s A si s f i x e d b y b o t h o x i d e p h a s e s . T h e r e f o r e , A s s h o w s t h e s m a l l e s t a v a i l a b i l i t y . T h ef i n d i n g s a r e s u m m a r i z e d i n T a b le V I I I .T h e t a b l e s h o w s t h a t t h e p o t e n t i a l o f t h e f o r e s t s o i l e l e m e n t s t o p o l l u t e th ee n v i r o n m e n t i n d o w n s t r e a m a r e a s is a s f o ll o w s : P b > C u = Z n > A s . T h e r e a s o n sf o r t h e d i f f e r e n t r e a c t i o n s t o l e a c h i n g p r o c e s s e s c a n g e n e r a l l y b e f o u n d i n t h es i m i la r i ty o f t h e c ry s t a l ra d ii o f h e a v y e l e m e n t s a s c o m p a r e d to F e a n d M n .

B a s e d o n t h e f i n d i n g s in t h e c o n t a m i n a t e d s o ils , th e h a z a r d o u s p o t e n t i al o f th es t r e a m s e d i m e n t s a n d s l a g s i n th e B l e ih t i tt e a r e a ( C l a u s t h a l - Z e l l e r fe l d , U p p e r H a r zM o u n t a i n s ) i s g i v e n i n T a b le I X .

A s d e m o n s t r a t e d b y T a b l e s V a n d I X , t h e c o n t a m i n a t e d fo r e s t so i ls a n d s l a g si n t h e B l e i h ~ i t t e a r e a , a n d t h e I n n e r s t e s e d i m e n t s m u s t b e c o n s i d e r e d a s a n e n v i -r o n m e n t a l r i s k f o r th e d o w n s t r e a m a re a s. T h e h a z a r d o u s p o t e n t i a l is c h a r a c te r i z e db y

- h i g h a m o u n t s o f e a s i l y a v a i l a b l e P b c o n c e n t r a t i o n s i n t h e f o r e st s o il s ;- h i g h a m o u n t s o f e a s il y a v a i la b l e P b , Z n a n d C u ( p a rt ia l l y ) in s t r e a m s e d i m e n t s

a n d s l a g s .T h e a p p l i c a t i o n o f c o m p a r i n g e lu t i o n p r o c e d u r e s a ll o w s a m o r e p r e c i s e d ia g n o -

s is o f t h e h a z a r d o u s p o t e n t i a l o f h e a v y e l e m e n t s i n f o re s t so il s. T h e r e l e as e o f M na n d F e f r o m s t r e a m s e d i m e n t s s h o w s t h e s a m e c h a r a c te r is t ic s a s f r o m f o r e s t s o il s( F i g . 4) . T h e r e f o r e , t h e r e s u l t s o f t h i s s t u d y a r e b e l i e v e d t o b e tr a n s f e r a b l e t o o t h e rs u b s t a n c e s .

T h e e s t i m a t e o f th e a v a i la b i li ty o f h e a v y e l e m e n t s f r o m o t h e r s u b s t a n c e s , e .g .m i n e r a l w a s t e s o f t h e i n d u s t r y ( f il te r d u s t s , w a s t e s o f t h e d e s u l f u r i c a t i o n o f f u m e s ,e t c .) r e q u i r e s s i m i l a r i n v e s t i g a t i o n s a s d e s c r i b e d i n th i s s tu d y .


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332 D. W, ZACHMANN AND R. BLOCK

TABLE IXEasily av ailable amounts of heavy elements in stream sedi-men ts and slag s (ppm; in brackets: percentage of total amoun t- cf. Tab le III and IV )

Sample Pb Zn Cu Asa) straem sed iments (Innerste river)IT 600 58 0(4 4) 5(4) i0(5) 0.07 (1.5)IT 512 294 0( 29 ) 142 0( 14 ) . 4 (1 ) < .01 ( - )IT 801 4 9 1 0 ( 4 7 ) 3 2 0 0 ( 3 4 ) 8 8 ( 1 3 ) < . 0 1 ( - )IT 805 4 6 9 0 ( 3 3 ) 2 0 7 0 ( 4 0 ) 1 8 0 ( 3 2 ) < . 0 1 ( -)b) Slags (B leihlitte smelting site)S1 2 3 4 0 ( 4 1 ) 1060(7) 5(.1.5) 0.86(5.5)$2 2 5 1 0 ( 4 1 ) 970( 8 ) 5 ( 1 .8 ) 0 .41 (2 .5 )

M a n y o f th e i n v e s t i g a te d m a t er ia l s s h o w v e r y h ig h a m o u n t s o f t o x i c e le m e n t sb o u n d a s c a r b o n a t e s , e s p e c i a l ly l ea d . U n d e r t h e a s p e c t o f d e c r e a s i n g s o i l p H ,t h i s e l e m e n t s p e c i a t i o n m u s t b e c o n s i d e r e d a s a n o t h e r h a z a r d o u s p o t e n t i a l f o r t h ec o n t a m i n a t i o n o f d o w n s t r e a m a re a s.

A c k n o w l e d g e m e n t sP a r ts o f th is s t u d y w e r e s u p p o r t e d b y a g r a n t o f th e V o l k s w a g e n F o u n d a t i o n ( Z .) .W e w o u l d l ik e t o t h a n k t h e s t a f f o f th e G e o c h e m i c a l L a b o r a t o r y f o r th e i r a n a ly t ic a lh e l p ( S . S c h e f l e r , R . L 6 h r , O . E w a l d ) . W e a r e g r a t e f u l t o J . J o h a n n s e n f o r h e ra s s i s t a n c e i n c o r r e c t i n g t h e m a n u s c r i p t.

A p p e n d i x : A n a l y t i c a l p r o c e d u r e sT h e a n a l y t i c a l p r o c e d u r e s u s e d f o l l o w t h e m e t h o d s a s d e s c r i b e d b y t h e G e r m a nI n d u s t r i a l N o r m s ( D I N )D I N 1 9 6 8 4 - 8 : D e t e r m i n a t i o n o f th e c a t io n e x c h a n g e c a p a c i ty o f s o il s a n d o f

e x c h a n g e a b l e c a t io n s .5 g o f a ir - d r ie d f in e s o i l is f il le d in a f u n n e l b e t w e e n t w o l a y e r s o f q u a r tz s a n d .4 0 m l o f a s o l u t i o n w i t h 2 5 g B a C I 2 9 6 H 2 0 / 1 0 0 0 m l ( p H = 7 ) i s p o u r e d t h re et i me s i n t o t he f unn e l a t i n t e r va l s o f a t l e a s t I hour . A f t e r ab ou t 15 hou r s , 100m l o f d is t il le d w a t e r i s p o u r e d i n t o t h e fu n n e l . T h e c a t i o n s a r e a n a l y z e d i n t h ec o m b i n e d e l u t i o n s .

D I N 38 4 1 4 - 4 : D e t e r m i n a ti o n o f s u b s t a n c e s e l u t e d b y w a t e r f ro m s lu r ri es a n ds e d i m e n t s .


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STUDIES OF THE AVAILABILITYOF TOXICHEAVYELEMENTS 3 3 3A s a m p l e a m o u n t e q u i v a l e n t t o 1 0 0 g o f a i r -d r i e d m a t e r i a l is p l a c e d i n a f la s kw i t h a v o l u m e o f 2 , 0 0 0 m l . 1 1 o f d i st i l le d w a t e r is a d d e d . T h e f l a sk is c a r e f u l l ys h a k e n f o r 2 4 h o u r s . T h e s o l u t io n i s fi lt ra t re d ( 4 5 # m ) b e f o r e t h e a n a l y t i c a ld e t e r m i n a t i o n .

D I N 3 8 4 1 4 - 7 : D i g e s t i o n o f s l ur r ie s a n d s e d i m e n t s b y a q u a r e gi a .3 g o f d r i e d a n d g r o u n d s a m p l e m a t e r i a l is p l a c e d i n t o a r e a c t i o n v e s s e l . 21 m lH C 1 ( 3 7 % ) a n d 7 m l H N O 3 ( 6 7 % ) a r e a d d e d . A r e f lu x c o o l e r a n d a n a d s o r p t i o nv e s s e l ( 1 0 m l H N O 3 ) a r e m o u n t e d o n t o t he r e a c t i o n v e s se l . A f te r s o m e h o u r so f p r e d i g e s t i o n a t r o o m t e m p e r a t u r e t h e m i x t u r e i s h e a t e d f o r t w o h o u r s . T h es o l u t io n o f th e a d s o r p t i o n v e s s e l is p o u r e d t h r o u g h t h e c o o l e r in t o th e r e a c t i o nv e s s e l . T h e a d s o r p t io n v e s s e l a n d c o o l e r a re r in s e d s e v e r a l t im e s w i th H N O 3a n d w a te r . T h e c o m b i n e d s o lu t io n s a r e a n a l y z e d f o r h e a v y e l e m e n t s .

Re f e r en c e s

Andreae, M . O.: 1986, Organoarsenic com pounds in the environment. In: Craig, R (ed.): Organometal-lic Com pounds in the Environment; Long mans, 1986; 198-228.Ball, J. W., Nordstrom, K. D., and Zachmann, D .: 1987, W AT EQ 4F - a personal computer Fortrantranslation of the geochemical model W ATE Q2 with revised data base. USG S open file report87-50, 108 pages.Block, R.: 199 2, Zu r Ermittlung der Schw ermetallbelastung im U mfeld der ehemaligen BleihiitteClausthal und der Innerste (H arz, Harzvorland) unter besonderer Berticksichtigung der ElementeArsen, Selen und Antimon sowie der Erfassung der Schwermetall-Bindungsforrnen in BOdenund FlufAsedimenten. - Ph.D .-thesis (in preparation); Tec hnical University Braunsch we ig, De pt.of Geosciences.Block, R . and Z achmann, D.: 1991, Soil pollution in the H arz Mountains (Oberharz) at the Bleihtittesme lting site; conce ntrations and availability of toxic heavy me tals, including arsen ic. Investiga-tion report, VW -Foundation, Techn. U niv. Braunschweig, Dept. of Geosciences, 79 p., (internalreport).Brtimmer, G . W., Gerth, J., and H erms, U .: 198 6, He avy Metal Species, M obility and A vailability inSoils. Zeitschr. Pflanzenernahrung und Bodenkunde 149, 382-398.Bundesgesetzblatt: 1992, Klarschlammverordnung (AbfKl~irV).Bundesgesetzblatt21, 912-935.D IN 19 684-8 - Deutsche N ormen: 197 7, Bodenuntersuchungsverfahren im LandwirtschaftlichenW asserbau; chemische Laboruntersuchungen; Bestimmung der Austauschkapazit~it des Bodensund de r austauschbaren Kationen. Beuth V erlag, Berlin.D IN 38 414-4 - Deutsche N ormen: 1984, Deutsche Einheitsveffahren zur W asser-, Abw asser- undSchlamm untersuchung; Schlamm und Sedimente (Gruppe S); Bestimmung der Eluierbarkeit mitW asser (S 4). Beuth Verlag, Berlin.D IN 38 414-7 - Deutsche N ormen: 1983, Deutsche Einheitsverfahren zur W asser-, Abw asser- undSchlamm untersuchung; Schlamm und Sedimente (Gruppe S); Aufschlug m it KO ningswasser zurnachfolge nden Bestim mu ng des s~iurelOslichen Anteils vo n Metallen (S 7). Beuth V erlag, Berlin.

DU es, G.: 198 7, Untersuchungen zu den Bindungsformen und 6kologisch w irksamen Fraktionenausgew~ihlter toxischer Schwerm etalle in ihrer Tiefenverteilung in H amburger B Oden. Thesis,Univ. Hamburg, Hamburger Bodenkundliche Arbeiten 9, 265 p.FO rstner, U.: 19 87 , M etal spec iation in solid wastes - factors affecting mob ility. In: Land ner, L.(ed.): Speciation of m etals in water, sediment and soil systems. Proceedings o f an InternationalWorkshop, Sunne, October 15-16, 1986; 13-41; New York.FOrstner, U. and Calmano, W.: 1 982 , Bindungsformen von Schw ermetallen in Baggerschl~tmm en.Vom W asser, 59, 83-92.


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334 D.W . ZACHM ANN AND R. BLOCKG o l l , M . : 1 99 0 , U n te r s u c h u n g e n z u r S c h w e rme ta l l b e l a s tu n g v o n W a ld b O de n d e s O b e rh a rz e s imB e re i c h d e s F o r s t a m te s v o n B a rd H a rz b u rg . T h e s i s , Te ch n . U n iv. B ra u n s c h w e ig , D e p t . o f G e o -

sc iences , 105 p . , (unpubl . ).G u n n , A . M . , W in n a rd , D . A . , a n d H u n t , D . T . E .: 1 9 8 8 , T ra c e m e ta l s p e c i a ti o n i n s e d ime n t s a n dso i l s . In : Kram er , J. R . and Al len , H . E . (eds .) : M eta l spec ia t ion . Theory , ana lys is and app l ica t ion .L e w is P u b l i s h e r s , C h e l se a .H a n u s c h , K . , G ro s s ma n n , H . , H e rb s t , K . -A . , R o s e , G . , a n d W o l f , H . U . : 1 98 5 , A r s e n i c a n d A r s e n i cc o mp o u n d s . I n : G e rh a r t z , W . ( e d .) : U l lm a n n ' s E n c y c lo p e d ia o f I n d u s t r i a l C h e mis t ry , V ol . A 3 ,1 1 3 -1 4 1 ; V C H V e r l a g s g e s e l ls c h a f t , W e in h e im.Hein , H . and Schw edt , G . : 1991 , R ich t l in ie n und Gren zwer te , Luf t - W asser - Bod en - Ab fa l l . 2 .Auf l . ; Voge l Ver lag ; Wti rzburg .Jakob , G . , Dunemann , L . , Zachmann , D . , and Brasser , T . : 1990 , Unte rsuchungen zur B indungsformvon S chw erm eta l len in ausgew~thl ten Abfa l len . AbfaUwirt . Jour. 2 , 7 /8 , 451-45 7 .L o r in g , D . H . a n d R a n ta l a , R . T . T. : 1 9 9 2, M a n u a l f o r t h e g e o c h e m ic a l a n a ly s i s o f m a r in e s e d ime n t sa n d s u s p e n d e d p a r t i c u l a t e ma t t e r. Ea rth Sc. Rev. 3 2 , 2 3 5 -2 8 3 .

L o tz e , T h .: 1 9 92 , U n te r s u c h u n g e n d e r B in d u n g s fo rme n v o n S c h w e rm e ta l l e n i n K u p fe r s c h i e f e r-h a ld e n d e s R a u m e s S a n g e rh a u s e n , u n t e r b e s o n d e re r B e ru c k s ic h t ig u n g ih r e s S c h a d s to f fe in t ra g e sin B idden. The s is , Techn . Univ. B raunschw eig , Dept . o f Geosc ien ces , 172 p . , (unpubl . ).M cBrid e , B . C . , Mer i lees , H . , Cu l len , W. R . , and P icke t t , W. : 1978 , An aerob ic and aerob ic a lky la t iono f a r s e n ic . I n : B r in k ma n , E E . a n d B e l l a ma , J. M . ( e d s .) : O rg a n o m e ta l s an d O rg a n im e ta l l o id s :O c c u r r e n c e a n d F a t e i n t h e E n v i ro n me n t ; A C S S y m p o s iu m; A m e r . C h e m. S o c . ; 9 4 --11 5 .M c L a re n , R . G . , W i l l i a ms , J . G . , a n d S w i f t , R . S . : 1 9 8 3, S o me O b s e rv a t io n s o n t h e D e s o rp t io n a n dD is t r i b u t io n B e h a v io u r o f C o p p e r w i th S o i l C o mp o n e n t s . J . Soi l Sc i ence 3 4 , 3 2 5 -3 3 1 .Meiwes , K . J . , K0nig , N . , Khnana , P . K . , P renze l , J . , and Ulr ich , B . : 1984 , Chemi-s c h e U n te r s u c h u n g s v e r f a h re n f t i r M in e ra lb o d e n , A u f l a g eh u mu s u n d W u rz e ln z u r C h a ra k -t e r i s i e ru n g u n d B e w e r tu n g d e r V e r s a u e ru n g in W a ld b 0 d e n . B e t . F o r s c h u n g s z e n t ru mW ald t~kosys teme /Walds te rben , G0t t ingen , 7 ; 1 -67 .N o w a k , H . a n d P re u l , E : 1 9 71 , U n te r s u c h u n g e n a b e r B le i - u n d Z in k g e h a l t e i n G e w ~i ss em d e sW e s th a rz e s . Beih. Geol. Jb. 105, Hannover.P a rk h u r s t , D . L ., T h o r s t e n so n , D . C . , a n d P lu mm e r , L . N . : 1 9 80 , P h re e q e - A c o m p u te r p ro g ra m fo rg e o c h e m ic a l c a l c u l a ti o n s . U .S .G .S . W a te r -R e s o u rc e s In v e s t i g a t io n s 8 0 -9 6 , 1 93 p .S a lom ons , W . and F t~rs tner, U . : 1980, Trac e Me ta l An a lys is on Po l lu ted Se d ime nts . I I . Eva lua t ion o fE n v i ro n me n ta l Imp a c t . Environmental and Technological Let ters 1 , 5 0 6 - 5 1 7 .Shannon , R . D . : 1976, Re v ise d e f fec t ive rad i i and sys tema t ic s tud ies o f in te ra tom ic d is tance s inh a l id e s a n d c h a l c o g e n id e s . Acta Cryst . 3 2 , 7 5 1 -7 6 7 .Tess ie r , A . , Cam pbe l l , P. G . C , and B isson , M. : 1979, Sequ en t ia l ex t rac t ion p roced ure fo r the sepa-r a t i o n o f p a r t i c u l a t e tr a c e m e ta l s . A n a l C h e m . 51, 7 , 844-851.

Vahte r , M. and M arafan te , E . : 1988 , In v ivo m ethy la t ion and de tox i f ica t ion o f a rsen ic . In : Cra ig , P. J .a n d G lo c k l in g , E ( e d s .) : T h e B io lo g i c a l A lc y l a t i o n o f H e a v y M e ta l s; R oy . S o c . C h e m. ; 5 -1 9 .

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