i 3

do

~

} ~

,~

`,;

~ ~~

V }

f~~ i F\N[~ PC 1R1.1SHERS

DEiJ~CATI(ON

For ~

•9xr

ie P

a~'islt

3i;li-r

ai.~

etli;

ti:niily, and r~n

nil:

a

Acquiring F:dixor:

i<~e

l :;

~eir

t

5'rojecY fdikit':

;111?en

1\-".

tii:

~rl:

~r•.

atl'

ier.

Ir..

- [.ibtsrn of !.k»agrtiss f.,at~.loging-in-Nublicatlon Dana

- Uc ;ca

d„ U~i

;lis

rn ~.

C,',:uundv:; ti.~

c;

co~:

he•i

iu,t

iq i~

uncl

:imd

rtt;

:l5

pf3CI }~

>gI1

C Rfi(L I.

V 1~'>

:.C

)Q[t

ti71

1118

t1Ui

1 %

1~~IIllilii7 T

. Di`U(5CI1

s)

C47).

~ I;

.~iu

d t u~

lic,;

,~ pli -al rcl

is n rs :uxl

ind~cs.

.1}l

i,h q

ti ~

;?I.

.3U`

,?-7

Cull. piga~r)

`.. 1.

\~

~ A

rhr~

:tis

tiy

(lrc ur.ci~*,.iics~. z GrruncE~yaic:--1'oGntiara.

f.. 'tiilr.

551oi9- 1C

"31

..4.~

i'.€ 3!>

I.

-3

(.II

'_:-

..i

'I~Iris

6~.<

Ic r~

,ni.

nn.

i..~orru:icin' r

.ix:4iuei Erma :iu

rfn-

n;i,- .u;ti h

i~iyi•,- re~

.vde

:l sui

irco

. l

ii:j

xint

c~l

ii it

:;ri

~i{ i,

yu. irc(

~,vith

~)..I I

ti L: i<'il~ ,

I:;CI

.i(}

L~Ei

i.r

61e.

' IA7(IICIIItY I.

r'\ ~

+i_le

vari

etz et m

~l~c~erut~v

are.

listed

~<e xs

c>:.

.d~l

e e(

frxn

hne i;ecr~ riauc

io ut ~.~

li;6

re

;idb

~ data ;!

rid

ir~l

~~r~

nnti

on, but

t1~

ainl

ira'

line? t

l'ie't~ui'zh ~;

lier i u'

ii>>i

,t5.,(ime

~~ .~

8=i;

.ir.

I: ti

tine ~

:+1x

(it~

ut

:i

l m ~ c

iials e, r

fli

t the ctm.equencis of

tktC

ir usr.

--~

ticid~cr ~

i;r; ~~

~,x~1: n

c~r any p:in

ntir,' be tepre dr:

.ed of t

~i

ivn.

ii.C

ed .

r~.:

tr~t

<-I`

brn

,i t

n~ ciiy i9

~utn

s, eic

ctro

n c' or

:n-.€f.ir.ics

inrluJin.uPh,; ncuF

roi.

~. iticr,>i'itnun~;. ~utd

re~oidi.'ri.~'~r lr

v,ut

y,.i

nfc»

~~~n

aiio

n sturtgr or rctti~~.~<t(sytueau

~v thout n

ri:,r

~~

r~i ~;ssins~ in ;

~~i~itim~ Fran? the

pub':i;;}ier.

"1'hr ccn ,rt

e ni t~

l<C

1irs5

d~x~s, not

esfetw

L•+ a~E~y

~, "„r gent ~d

~li

trifa,:tii~+a..fc~r ~r

cimU

tir,

>n.

felt a

r~tpi[ing

c~,

~ . . < x s

+>r +;~+plc

a~~t

..iti

~.. r

. u:~us"un n

.ust be n

l.~~aii icd i

n-u rit

i~z~

frr>ni (.

.RC;

7 ri~ss 1

it.

suc'ti cr,

pyin

};.

)F~.a:t :I

I mc

~~.~

i•~i

ct4 :u ::It(. 1'rc : ~7C. 7

~.~Q

U Cr

>'(~

Vraf

o.

~ vd

., ~:\

Y', ;3

c>ca

Jia

tun

f'lori<3a

S~i.

}3'1

.

-T

188

GCtQ

UIVT

~t+V

ATE}

ZGEO

CI-(

EM[S

TftY

imrn

cibi

lira

Cro~

~ of g

rcru

nci~

~~~~

ter

c;c~n4irnix~anCs c

axz

alsc

a occur under r

educifig c

ondi

tion

s.The fol

lo~~

in~

c~~'

e:ra

El r

eact

ion ha

s been shown to .o

ccur

in lake yed

imei

~t ~vid~ r

e~tc

five

C)C~T:371tC It1a CI

C.]":~~'~y

4Pe~t)3~{~~ + ~~C

) ~- +c)C3~._C3 --~

4FeS k SIiC:O'y,-t ].

7.FIL(~ + G(7,

(13-

1>)

[,ii t

his ~•eacricm 9r

i~u an

ct-s

ulfa

te are rc'

citi

ced le

y ~l

~t: o

a~g:~c~ir. msa

l:te

r CH~~S and precipitate;cl

as C

I1C.

It071

i11Q

110S

l1IF

ICIC

' Fc

S. The r

eac~

cion

is ca

taly

zed by s

ulfate-redzaein~ M

aeCe

ria.

The

gune

:ral

r(ot

7 air bicarbonate pr

ovid

es a

cid-

.neu

tral

izrn

capacsty to

tEie sys

tem.

'll

~is

nect

ttai

-iz

atic

~n r

occh:~r~isrri will cml

~-• k~

e per~xianent if the

I~e

$ is riot al

lowe

d is oxidise in

t.11

e future,

such

.:.i

s E~}~ bu

rial

. ia

~ It3ke

sedi:inenrs. Thi

Gaeu

tea:

lira

ti<.

~n nay a

lso

~cc~

ir u

t an a

c~ul

l'er

e:nv

imnm

ent

Allf

;l'e

clley acidic ~

ilun

7e con

tact

s a zone of rea

ctiv

e or

gani

c mater that f3as

sLd~

fici

es~i

t rc~ctucing c

apacity [o low

er t

l~e ~h t

t~ t

he s

tability f

ic(cl of the

sul

fide

m ncr

aJs

Iri ~ufrimary, t~~e most common reactiee ne

utra

lizi

n agentS'in su

rfac

e ~va[ex~

oa~ g~

ciu~

~cl-

u-ater sys

cean

s are

dissUlvetl tiicarbonace ai3d rar

iiae

aate

; k?

~cwe

cer,

the

~i.

eu~r

alix

ing c~

paci

ry<:~

f t1~is so

urce

is

c~er

;r li~

ni[e

tl. GarbUnaee minerals present in the system p

ro~i

cle the ne

xtm<>sc reactive ~I~ase, and eheir neuer<aizing capacity is a fi~nc>tic~n of the

ir coi

~cen

tra[

ion and

~ava

ilal

~il:

it~~

ua the

ac it

tic so

lutP

c>n.

Rap

id p

Gett

iy>i

tati

on c

~F feitTiliydsir~

can

nEut

rail

izaY

idn

big

raruc>n~iee. n

uner

~ils

m~a

y~ c~~

ai the

rar

b~na

te solids, red

ucin

g their

reactivia~, ar n

iat-

ce~at

the

sulf

ides

sninexais, i

~aakinn

thea

n le

ss s

iesc

c:p[

il~l

e to

cvntinucci uxii.k~icic~n.' If

zieitt~ec

cli,soE~•ed nr sol

icE i»or};anic cari~on is }~

iese

nt in tI

~e se=stem, then ~rgani<; a<;cls ma}>

prc~

cici

eBorne

Ili,'~itecl ri

eutr

alir

;rid

; c:i~,a<:iCy ~rUpurt:iottal to

tlic

ir dis

solu

c:cl

concenirat4~n. As ehe pH

~>f' t:

li~ syscem c

[ecr

c~a.

~c:s

, ration exelian~e,

~s wel

l as

the

cli

ss<~

luti

c7a~

c>f cla

y ~~

~ine

a'al

s, inay

cons

urrf

e ac

idit

y. i rid

er rectucin~ ccznditions, t~a

cter

ial su(fac

e, tedxicut.~n c

oin provide

~tlk

a-li

izit

}~ to

ttie system

b}~

tkie. ;generation of t7icarbt~nate. Residual neu

n~al

izin

g ca

paci

ty will he

pi~c

>cid

ect by the p

ri.in<trn si

lica

te and a

ltim

ir~c

~sil

icat

e rninea•als; but these

re:~

ctio

ns are slew

can

t]ie rime Yr

a~x~

e o(' cy~7ical g

r<>unc~~~•at<:r ,r

esid

ence

ana

l ar

e nc~t e~~

~ect

ed to Ue r

aprd

n~:u

u<il

rzc;

rs of

~u~icii<: sakuti<>ns.

Ttic

:,5e

~;c

:ner

a[ aci

t3-n

ei.n

rali

zing

reacti<rns are: not

]imiteci tv

the ea

anip

le of pgrlte

oxid

atic

~i~.

.;1a

~y acidic sc

xrrc

e ~ti

~ill tend r

c~ be tie

iitr

aliz

ed l

ey on€ or

mare of

chc.~e~ mech:in'ssms.

~z.z.

,~~~

luic

; ~~v

ir,.

c~N!

,nr~

~~rs

Sirl

tici

e mi

nera

l ox

idat

icrn

.:an

d tl

~e X~rc~clucti~n ~~f

~ICICSIC CpT

1CI1

IlUC

LS; ~w ~lcscribed

al~o

ti-e

, occ

urin

si vst

ric:

n- of man-~7~acie eneircinments .a

rt( in

cer

tain

ui~peiturbed Sy

sCem

s::'

~cic

lic cc

incl

itio

nsc~eau~cl 1

:>v irucsran a

ctivities

rncl

iide

~c

ic u

rine

. c3

rain

a~e;

sto

t~ge

piles aE ore, u~astc; rick,

and tailii7s,s; and l

akes

ass

~>ci

ated

t~~

itli

~~Ycac•<~ti<rn

cif orc~ c

lePc

~sit

s. ?31e rhat~rterisdes c

ifma

n-rr

ia.c

3e and n

u~urtlly a

.cic3i~ environrr~cnts arc cieseribed

in t

his section.

ilia

tura

lly Acidic Con

c~it

sans

Tl~e

~ r,a~ural r

~cc:i.~rrenre

<it hi

gt~I

y a<•i~lic con

riit

ions

cii

~e ro, for esazn~ile, pyrite i~~idation

isse7nie~kha[

rare

l~r

caus

e the

rate of a

cid

n~en

erat

ian

clan bc:

hai~

ince

ii by

' ne~7llalizat can

r~~acrionti

tiv'<iEer se

nd <

~~~-geii in

tlse.

~.tn

s<tn

~nr~

>ci zone ~

=ill

axic3ize

~~yr

ite,

bLi

t tt

~e s~lutiorz

~n;:

~y in turn be

ncut

~ il

izec

l a:~

it flo

4vs

t}irc>ti;,h th

e un

,sat

urat

e~l and sat

urat

ed zcmes t>n i

t5

rEC~CI- i6M

IS7'

li`!

OF ACiD 113tVE bV

ASTE

1.

89

nactrrall~~ sv

eaeh

ers ai

ic3 s1o

~~~q

e,~

c~ps

es new sulfide minerals

tee r~

xidi

zing

conaitioiis; ~lecixan-

ical

weathering su

ch as mass ~4a

stin

~, which i

s pr

imar

ily .iinpQrt~tnt in areas of lii~h r

elie

f,.may r

apid

ly expose acid-proctuz~ing mi

nera

ls to

eaitih s

urface e

t>nc

.liC

ians

. Iii dt

ese casHs

1oc11ized zones cif aci

dity

ntay he cre

<ate

cT z~n

ci sur

face

cca

cc~~

s mp

g= be acidic Ex~aeise of` the

relatively lin

lite

ci a~pUitun.ities

Ec~r nc.

utra

liza

tinn

bq rvaeer;'rc>cf: i

nerracti~ns. T'h

e Sttmmit~~ille

fCc~lWractca)

arezt co

nCai

ns a r

iuml

ier

i'~f

dra

in~i

gcs

ellat a~

ipea

r co

haee h

e~.n

iru

pact

eci.

lit

•ac

id e

cinc

liti

ont;

produced'bp the nataral pcc

>ces

s cif sulfir.[e mineral

w~ei

ithc

rmg.

'•>~

~"

Acid .Mine Drainage

cJne

of tl~e in

gst coni.mon occ

urre

nces

~f acidic cc

mcli

tion

s is

:tss<~ciated

w•iCh

thc~

mining

of coal

anti

vase

or p

reci

ous

metal,.

P~ry•ite occGiis

with th

e: are material be

caus

e di

een

viro

nmen

C in

whicil~ the

eaal or r

i~etais were ete~ositcci i

s, reducing

~inc

3 as cpnckiicive to

the

!'c'

~rn~

.ati

gn c

>f ~

y~ri

te and ether sut6de

rni:ner~ls ai~n~ ~

ciit

t c[ie r

n~e, i~linin{; ci~

~era

tinn

sexpose ~ut~cle ,ni

iner

ais in

like Ix

~st :

rock to a[mnsphcric oxygen eit

her in

the. tr

nde.

r~;r

r~uc

~ei

tiru

rkin

gs or in sur

fare

s~~i

is. Tn the

cas

e of rea

l depcasi[s, pyrite

i a miner cc~mporienc of

€tie

<7r~anic a

re. material;

[7ocvever•,

foi~

meal d~pcnits, p

grite ma}° be pt

csen

t ac

h.igli

eonc

entr

at ins rel

ativ

e. tc

~ th

e me

tal being; es

tr~~

c[c:

ci. In eiC

her ca

se it does nt~t

a~e quire large

amounts ref pyrite to

create

l~ig

hlt~

aci

dic conditions.

T'!ie oc

+~ua

encc

cif

aci

d ar

sine

cii

<iin

age in the copper zin

c ~c:st Sh

asta

D-Siriin~; Di

stri

ctc>f no

rthe

rn. Calif~mia I~xs been ea~tensively st

udie

d he

clus

e c>f it

s impact an nearby surface.

c~~a

tcr.

`lo

rci~

sti~

<:>a

~ et. a

l.'> chxalctr.ri:zed .mi

ne e

ffluc:nc and i

ts effect on Iii

x~tc

]er Cr

eek and

cia~mstream Si

ring

C:r

ec:k

. Trey m

easua~cd ~,7H ~~a

lues

<Es l

c~~s

as

't, t

in

the

arsine effluent

~xitla t

h.e

p1-i

in

tl~e creeks

incrc;asing co

2) aver a d

ista

nce.

o~ 7

:-~ k

~r~ Frc>m

tfxc po

int

c}f

effl

uent

cttise:har~e. I

roai <

knd

sulfate

cocrc:eritra'aons

exre

ecle

cl 10, 00 ~

u7d

6Q,C

le~C

) a7

glT„

resg

ecti

kely

; in

th

e ef

~1'u

enc and ~

i~.c

re~s

ed .downstream to Irs

s tl

~ag~

100 mg; I, dcGc

tc>

dilu

tioz

l and ~ro1>a}~te pr

eciP

irat

on of i~

•on ri

nd s~itfate mi

nera

ls, su

r.Jz

sis f

erii

llyd

~~it

e (t~e[(~f-11.,~

ant[ jarosite (K~ e,[:iO,~I,(UH7„}, :~l

c~n~

the

surface +cats c (t

owpa

th, al

umii

uzm c~ncenzr.~tions

clet

~rca

s~ from 1

4~E~ t~ 47 rn~;'L, p;~

rt at

iy~ Ni

ue . perhaps t

<> t

Eie

~rt.

cipi

catz

on c

>E aluminum

stx{

f3rC

zra

inei

~als

such as

jurt~attitc: (AI

ISO~

I[(~

Hj•5

i~2(~1.

The eftecC Uk

aci

d mine tia

.~in

age qr~ Vest Sc~

utw~

Cree l.

, w.

hic}

i is

noa

t~~ of Bou

lder

lncf

Sp~~

ing Cr

eeks

and e

lrains int

o Sliast~i Lak

e, ila

s been scuc(ied 17

q I~

ilip

c~k ec a

l ~~ lhey also

founel law pH an~i hi

gh txletal

anti

sulfa[e conrantratians in t

}ie cr

eek

s~~r

cral

miles

d<~w

ngra

ciie

nt of mine sites ,~7

r~ng

~esc 3cl

uaw•

Cre

ek; li~wever, th

e ~I

-I n:a

s generally

t~i~

;her

t;2.

j ccs S;>) tha

n. at }3

ould

er and

. S~

~rin

g Creeks and the d

is,5

alt~

eci cc~neentratzcan~ c

vc:r

e a1

1.~;

ener

alle

Ies

s than ]600 mg~L. 'f

'~iey ~>

bsc:

rved

. ~n attapr~hous orange

prec

ipit

ate a~

,scc

iaie

d.~~

~ith

alg

ae. in r

.iz~

scr

eam be

ds,

c?.~

hick

~ [hey believed ~>as ferric

E~ydros:ide

car a mixture of

ferric hy~

clrc

'~ai

cle and j

ar•oSiee. L•lEvated arsenic eoncentraricrris <>7:0 µ

g,'1

,) wer

e; redr~ced

ec~

l~eka~v ciete~eican level (1 µ;1.l,) a slx<ast clisrcence frnm the

sou

rce as tli

e: ai;~enic«

- ~is removed

Eroc

n so

iuti

bn pr~halily by adsorptitzn a

nti'

s tl~e ~reci}~itatin~; ire

>n m

inerals. '[

9~cs

e tti~~o s9~cs

i.n tl~e Wiest ~h.

asta

til

inin

g l~

istr

icc iI

lust

rate

t(~e (

~i~;

k~ inability of so

n ac

idic

, me

tal -ri

ch sol

utic

m.in

an ezz

i~i~

~onm

ent

wieI

i lour-neutralizing

at~i

Iiry

.St

rip

mi.n

ii~h

of coa

l al

sci

1'ias th

e potc;ruial f

c~r Produung acidic

ci~n

diti

c>ns

rf di

e cc~sil

cont

ains

sulfide mincrils and has a l~~~v-neutriliring ca

pai,

icy.

Kai

~itl

xan:

~si,

et

a1,=' sam~lecE

soil

c~hrr.iuns and sUrf~~:e z~•aCcr froFn ~mmclaimed and p

lrti

atEy

rec

laim

ed cta

cers

heds

tti.

i.t]~

ac~

t.~e

c;n

stri

p-a»

ir7e

d .in K~ntu~k~~. '.['liep found that

a£~cer als

nosc

2C)

vean since mininh

Ct'_

~iSe

c{. I

Jl~ nE

I cif th

t~ Siirfa~r

~.>.

,r4z

r :,.,.a ~

.;:r .,, ~z

~.;E~ ,

y ....

....

....

... ~~ - .~

>,

, .,

~9~

URC7UND~NATER.GEOCiiEA~tiJ'TRY

acidic as

ai•e. su

rfac

e ~•

ater

s. Sto

llen

werk

'~ 3

nvestl~±atcd the

cot

rGac

t of

aeiciic Fva.ter with

alluvisa.E a

quif

er s

r~at

eria

] in

the

Ulo

Y~e-

t~fi

2mi capper mining

district aF Arizona. The mosC

conc

aA~v

nat~

;d gi•ouudwater near t}s

e s<

~itr

e~ J

~sic~l

~~ pH ~

f' 33 and His

s<}l

v~d cc

~nee

ntra

tie~

nsof 9604 n~g

;'L SO ~ ~; '24

10 i

nfi>

'L f

~e, 3t

)0 mg~ L Al, and. 20

t) mglI. copper, Unc

cigr

tarn

inat

ecl

parts of the

~illi~v uni cantainecl about, t~.3

~~ei~;l7f

~~u

calc

:ite

, which pro

vide

s the. pri

mary

neutralizing ca

paci

Cp i

n tFie aquite~r sys

tem.

Year t

he s

ource;. th

e calcite

kLaci

disscih~eci

sili

cn~~

inb a lo~

~-pI

{ flume to farm. iz

i i(i

e aq

uife

r, Over a distance

t~f 20 km ftt

7m the

s<~

urce

,t.t

~c. pH c>£ the grot~ndc, ;

ater~ increased, slowly Crozsa 3.

3 tt> abaue ~.

3 at

which ~<ii.nt 3t

increased

re(ati~~ely rapidly oven the .ne

at t~v

o ki

lcmi

eter

s to

7. Thy neutralized gro

unci

~vat

er has vein

low Fe,

ril, <intl Gu concentratiorts (<1 m~;

'l),

while the sulfate Icvel (?OQO rng

r`L)

remains

~~e11 abc.~ve the

back

grc.

~und

concentration (?~ mg/I,). T7~

e c[

ecre

ase in

Fe cc~

ncen

crat

ion is

ater

ibut

c~ to zl

~e loc

i= solubilittr of ~'

e(QH

)3 at ne

utr<

~l p3i

..Di

ssul

cecC

aluminum.levels ap~cared.

t~ b<~

lin

~ite

;d 1>y d

i.e p3

rci~

itat

ion of :im

c~rp

l~o~

as AI(

(~H); ae

pH > 4.7 anc

i A1C)FISd~ at

. pH;

< •

~}.J

. T~I1C

C4>17Cf:;Iltl.ition ~f sta

fate

. is cci

niro

lled

: fe

y t~se rei

aciv

e[p sr~ltlble mi

nera

l ~~sum,

ti+~l~ich e~xplaias the high i

c~r~l ev

en.

i.n th

e ne

u[ca

lize

cl ~~•

;~te

r..A

tten

mati

on c

if the metals Cu,

La, ~1n

, Ii

i, ant

i Zn aloi~5 r]

ie grc

>und

~~at

er fIo

tupa

tlr appeared T.o lx;

c~nt

rc~l

led Icy ad5or~tic>n

c~rt

to f

erri

.}t}

tir~

irc,

."Plie

least li

kely

set

ting

for t

:he oc

curr

ence

<>f aci

d mine dra

inag

e is a mine s

ite in

earbc>nate, terrain; hoc

~~ev

er, siclficle

r>>Kiclati<>n ~;an s

till produce grc

~und

u~at

erc~

ntan

iiza

at.i

nn:

The zi.uc-lead. mines nea

r Sliutfsl~u7'g>

~Ylisc:<>nsin, ar

c Ine~teet ui a ca

rh~n

a[e

aqu~

'er.

Tlvs

aqui

fer was cic~vater«I during; cni

n.in

g ~t

llc.

~u~i

ng con

ta.c

t of the suEfi~ie mi

neta

:ts (~pritc, ga

lena

fYbS], anc

f sF~halerite (LnS]) ~~

ith at

nu>s

Pi~e

ric

air. 'I

'orut'~ fannd .th

at the

car~onc~ce mi

nera

ls'.

c]olomite ant[ eal

cit~

~flecticel~ n

eutr<.i:lized ac

id p

rcadt.ic~Scm and that

sicle7•ite fFrCO) an~

9ferriincirite limited iron con

cent

rari

o~i to

an acceptable level. H~~=ct=er, the sulfate: ]c

del

in

s re

~und

t~-a

cer .alloc~red t

o rc:c:ntea• the

mine since

li[z

tcig

rvn

u1' t:

he main i

tiizae ~~g

cki[

ag i

ii11

"'9 is ele

cace

ci ()C co 3~

0{) ni

gtl;

) cc

~ith

in. a hal

f mile nF the mu~

c. Cal

cula

tion

ref t12e ~pPscim

s~ie

uraC

ic.>

n indices

ft.~r

~;ro

uzid

~vat

er stt

nipl

es sho~'eci

it to ue tii

nder

satr

irac

e~i in most cas

esdespite

Ilis;h d

isso

lved

levels of

calcium a

x1c~

sul

fate

. If

gypsum is p~

- ese

azt as

a k~yprociure

o€ st

.ilf

icle

mi~t~ra}

c~xicl~~ti.orl ir

i the

mine ~~•arkings, Ll

ien

tlie: c

iiss

r~Iv

e~i 5~ilfate.fix~m cll

ssol

ut3u

ncif th

is ~y~~sum u

~t~ the

~~o'

~~rt

cisv

aCer

is cl

ttut

ec] kn

r mixing wit

h freshwater a short dis

tanc

ePram the

ruorkin~s. 1"Oran c

t~nc

luc~

e<I .hat the sulfate can

t~in

ia~a

tia»

is Igcalizeci and. ki

llde

crea

se wiCh

ti~n~ Ic

y cc'>ntinued

ciissc~ltitiun grid removal c>E the

sou

rce and ci tiiuon of tYze

<ontarrtmaceit ~;roYinctwatec.

Ore Storage,. Mu%e Waste anti Ta

ilin

gs Pil

esT'.tie presence of s ilfide-c;c~ntaining <

~re,

inr

nc ~vasrc>, or

.mill.. tai

ling

s on the surface of the

earth

crc-

ekes

a loc

alsz

eJ environzn~:ne wiel7 a high

3~ot

en[i

al for aci

d pr

~duc

tirm

. O~

idxr

ixxg

~~~a

ter ~a

erco

lati

ng thr

c,ug

h tl

~e m~tcri~l di

sc~

ic~e

s the

tiu1(xde min

eral

s, treating acidic eon-

diri

o.r~

s i~aila~ss

ttrt

m~accrial al

so contains neutralising solids, fn th

e long term

rlie overall

raCe~ of

oxi

clau

on ~k

itl

tie

ccin

tr<.

~llc

ct ley tht

cfelieery cif oxygen [6 t

.hE su

lfid

e mi

nera

ls.

(7xyg~n can I

've cr

ansp

oGCe

cl i

.~y cl

ifhi

sion

in

CIYe has

phase k

oa' tt

ras~

Curc

ite~

[ conc~iticros anc

~ci

i~s<

~Ic•

ec( in the

sali.~t.icm phase. Eor

sa.tur~~ced co

nzl

tic~

i~,s

.-° '

i"he

pro5ressi~n of acidic ccm-

ciit

ions

in the s~.ibsurface l.~enear.h

tl~e p

ile

~:vilt he a fua

:cti

ian of fhc

flr~c of aci

cli[

y fmm ehe

pik and t

:1ie n

eutr<ilr..rng caPaciry•

c~F t(~e naC

ive

n~at

erla

l.F3

1ow~

c~s an

t( Jaznbc>r~f ev

zlua

ted

t}ie

Ro

r~:w

a[c~

a~ g

eocheii~istrq ~f su3

ftde

cailin~s a

t ~

(;F.

t?CF

I E,'vl(S"CkZY QF ACl p MINE WASTE

lye

acid

gen

erai

ing

abil

ity•

Shan neurr~lizin~ cap

acit

y. Geo

rhea

uica

l: processes other t

han disso-

lution <

.~f c

arU~e~are minera.ts th

a[ can neu

ti~l

ize

ttie aci

d are

disso.tuti<~n of aluminositicate

In3n

ex~a

ls,.

di~,solutian of I

'e-

anc~

A,1-t~gdre~xide minez-a

ls, and I-

I~ adsorptinn on mi

nera

lsu

rfac

es.

Tt is calculated c

(tac the: ac

id ;enerateci in

oti

dizi

n~ i :m c

i£ tailin€s requires a 2~-

in tlo~vpath t

ai tx neutratiu;d try these rea

ctio

ns. Po

r- e~~

is reason the acid ~il

tAme

can moti~e

sue of the

zone of act

ive.

aci

d generation into dY

e to

wer

ceil

ings

anc

i. the

natitie m

aterial

tael

ow the p

ile.

'T`h

e calculati~.~n ~f mu~eraf saturation inc&ccs

~+1l

owec

l Bowes and ,Jaxnbor to ide

ntif

ygo

ssil

ile

mine

ral-

phases lim

itin

g sgluticin

cc~mpositi~~Y in t

ktis

r.~

aili

ngs pi

le.

C;gethite {a-

FeOQI~), lepidc}crocite (y-FeOQH), feccihydriCe

<Fe(OIiIx), j~

rnsi

te CKFe3[SQ; J,(~I-I] {;)

, and

gypsum {GaS0.5 ZT-i

~O) Is

mit dZe so

luti

on cancentratians of the mzjar ion

s, Pe'

", 5C)

j-,

C:az

`,Na

`, anc

t K- in the pon

e: wat

er. Lead may 17e Jimitcd by ang

le ite

(}~bSn~; and Cr n~~

y be

Limited by the p

reei

pita

tie~

n ~i' anu7z~lioti~ C

r(OI

-I)~

, while Cu i

s pret~ipiiated as cov

clli

te(C

tiS:

) }~e

lon=

the

znne of active ox- i

clat

ion.

There d~~ not appear TW ti

e any mineral solut>ility

limits can Co; ~4

fai, Ni;

or Zn'caticentrations; therefore

iE is li

kely

[3~t th

e mi

gr{t

on of the

semccals thr

oagl

i ch

c ta

ilin

gs is primarily s£fccted by aEisUrixinn/ctes<~rptiois pivicesscs. Giverx

the current ra

te oi'

c>xiciatian of thi

s ta

ilin

gs pil

e and the

amount r~F su

ffi,

de min

eral

s pi~esec~t,

it. .i

s calculated that these tailings Rill canCinue to gc:nerafe ac

id f

ear 5cwet.il centtvies unl

ess

the o~cp~en source

is cur

off

<>r

add

itio

nal

neutralizing ~3~

ents

are

. added.

Tl~e

precipi[aci~in

cif secondary ini

neea

l;s at

dif

fere

nt "fr

onks

" i.n a Czl

iiin

~s fil

e ca

ai aff

ect

t17~

sno

ve~n

ei;t

~f ~orewater

t:>}s fo

rnai

nb hor

izon

tal

E~~.

rzic

rs to

vert

ical

floe>, Bla~vcs e[ al..'z

discuss [l

ie ncciu•rencc of a i~ sc

onti

nvou

s, cemented layer (hardpacX7 at the

: Qu~hec tai

liri

~;s

pile

des

criU

ed above. '['h

is leper is

'1 eo ~ cm thick anc

t occurs at the de

pth.

of act

i~~e

sul

fide

rsii

nera

l o~

dati

en. Cunenration

is ~ec

~d2t

cect

t.~q Fe(III) mi

nera

ls; principal(}r ~<>edzlre.; lepi-

clr~

crc>

cite

r feirihpdrste, and j

arosice. g

ilt a sep

arat

e, ina

ctiv

e, sul

fide

c~

xiti

ngs

site i

n 'dew

F3ru

nsti

vick

, they des

crib

e: ano

ther

. type of har

dpan

that is 1Q c~ 15 cm thick and c~>ntinur>us

anal

occurs 2Q t

q' 3p cm belgw t

he. de~tt~ of ac

tive

r>x

icla

tio[

i of

Che f

iitir ap

Pc~z

i.~a

nce

<~f

ca]cit~. Pn

thi~

4 ease cen

~ent

atic

an ii ea

user

I Tay th

e pr

ecip

itat

ion of gupstun and Fe(

II) sr

ilid

~;ha

ses,

pri

nci}

~all

y, nie

iant

erit

e (F

c;50

> 7H.(~). 1'

lie I<icl; of precipitaYi~n of th

e Fe(III) cr

ct~i

e;a

nd sulfate minerals at

thzs

s`ie

e is aurit~uted to a l~i~lier sCiIficie cc

~nte

iat in the

tailings ag

cta.:la~>er pI-T; wt

ixc h incrca:es th

e so

lubi

lity

of the l~

a(I[I) minerals, minimizing their fcirinatian.

Cc~n

ccnt

rati

ons ~f Pe(Ii} and siiIfate in

crea

se u

ntil

melanterite

i>ecoiries s

upecsatursatc;d.

Gypsum a

lso

t7re

cipi

tate

s ~v

l~en

calcite i

s en

coun

Ce:c

ed 1~ecause dr

e dissolution

off' calcite

releases calcium t

hat cdn coTnUine «ith s

ulfate to form ~~psuzn. 'I`tie presence

cif these

liardnan lay

ers_

in:t

he tai

ling

s piles are vi

ec~r

ed as a ben

efit

because the

y lima the

movement

cif s<

~Iut

ion anti gas

es r

l souglx tki

e ceactiYe tailin„s naaeerial.

Pyri

te is a t

xkiic~uitcs~is eon

stit

ueau

in caaI..in :t revietiv c7f

wat

er-g

aali

Cy issues aasociaCect

euit

h ce

~al scUrage, Ila

~•is

-an

d f3oegly=;

cozza~i.is c

4~tFi

ern le

acha

te fr<~m c

oal st

orag

e pi

les.

They Fou

ncl pF3

vsrlues as

low as

2; 1, iron

cancentrrticins as h

i;~l~ as

)3,UQ~

mg:'1.., and

sull

aCe:

.lev

els to 12,00 in;

;lL:

Con

cent

rati

ons

bi' Zn, YID

, As

, Cu, C

r, and. AI zxeeedeci 1

m~;CL in

the maioritt- of t17e 'tat>t~latecl le

acha

te compns3ti~ns. Hetz et

al.z

" identified the

ininerAis melancerite (xe50;

•7E~

:~C7

) end feci7hydrite as eoi~cencration-li~tutin~ n~

sner

als in a

.leacE :ing sniciy oE

.~pp

alac

hian

coa

ls. TE

iesc

: nuneraLs art

. fairly sc~luhie re

nder

khe

can

di[i

p~1s

cif tk

te coal

pile

and c

to not

limit soluzi~n cG

ncen

traa

~ns

tc~ lc.~~ le

vels

. Th

eS~ recommend

r;.ua~iiatinn rR.. .~.{A:r..~„ ..F i:.,,

.,,.

....

... ........ ..

t _.

i .. ..

e...

,.

..

192

C;R.

C)t1

NCYG

VATE

R GE

OCHE

M.IS

"I'k

lY

rnari~~

vi' these

sites

it has Y

~eea

~ found t

hat

tEie ~

.7H

<.>f the

leacitate is

rai

sed.

. from <

f valtic

~>f Ee

s~ than 2 in th

e tail.ir~~;5

tc:a ne

ar iic

°utr

al Icy

` contact wit

h le

ss than ont meter of su

l~sc

irta

cerk

itiv

e ix

is~e

eria

l. ~1c

.~st

of the

se sites are ir.

die

ax~iel to

se:miaa~itl ~re

ster

n Lnited Sea

tes ~~

here

calcite

~s a con

isno

n: ~~r

irna

n ~r

tic

cond

ary mineiat in

the soil. Cal

cite

neu

tr.A

lizc

s th

e acid,

leadi.Gac; to th

e pr

ecip

itst

cicm

a1~ oth

er i~i

incr

als such as

1`errihydrite, gypsum, AI(UI~}~, anti

AtOHSO„ (ac I

oY~•

pI3

). C

Jther

tnet

.tl cc>ntaminanrs and rAc~ic~nucli~l<s a

ssc~

~.ia

e~d'

c~id

~ [f

xele

aci~

cate

~ appear t~ he ads~rt>ed i

a.r coP

rc.c

ipit

acec

l wicti these se

caiz

dar}

~ mi

nera

ls. 7"

he mast

mobi

le contaminant at diesr

sitc

4 is usu

ally

sul

i'at

e, ~~~

h:ic

h is pre

seni

at elew•atecl. c«ncen-

tractions in gro

unci

~vu[

er bec

ause

of

tl7e~ re

l~~~

ip~l

y hi

gYi ,tiolubiliry of KS~psueir.

nC~a

i.ax

~.5

Lakes and c

7~kier suc

fare

cirater b

acii

es .may l:~zcome

~icidre~ I

~eiaiise. of tPi

e itiflp~t~ Uf

aci

d~ti

este

rs fi~

on~ mule ti~

-ork

ings

, as

in th

e ca

re of mine fit lak

es, or bec

ause

of aci

d ~rerip ta[ip~x

i~f regions

cif elrvate<t

aun~sE~ll~ric content. c

if 4tr

ici-

pmci

cici

ng g ise

s, csp

ecia

tty 50K anti

\C7x. The ge~chen~istry~ of these t

cv<.

~ envirc>ni~ze»ts wi

th res

pect

ro .a

cid ge

nera

tion

ant

isteiitralizat.ian is

discussed in th

is sec

cic~

Fi.

bTir

ce I'iC Lakes

C3pc:n-pit, tx

ard-

rr_~

ck i~unin~; f

'or m

etals cc

r~,i

3non

ly extends bel

c~~v

the «pa

ter takile and req

ui~'

esde

c~~a

ceri

nr; ciiirin~ t

tic n~

irnn

~; prcx~css, At tF~e e

,z:~ssati~n

c7f n5

zzii

ng; the

pit nt

fs R~ith v

~~aC

er'

to ¢

i~~

IevE:l ~

~f the cvatcr ta

ble cr

eati

ng z tal

e [hat.

ri~aFr b

c: tireiy

laz~

ge. (

ct~n

t~in

in~ >1

~;gQ

0atcre-[eee «

~~ ~

,~-a

tc~r

). ~~%

ate -duality issic:; assoriatecl t

i;pi

th these lak

es k

iati

>e l:~eerx a~e

uiew

eci

1}y

hillier ct al."' 13

rcaiuse of iht pr4sex~ce ;~f sul

fide

n~incrals ~xs

s<~c

ate

d ~~

titl

7 the

tyre iz~

ater

ial

anti d1e rxaxis~.ire ceF

rE~ese.~ min

~~ia

ls i<7 aLn

u~sp

heri

c cc

mdre

iean

s <I

r,Ui

ng iat

inin

g, wae

ur draining

inu.

~ rl

~e p

ir. f

~as the. ~o[enLiai to be <<cidic. 7'I~c ii

ec:p

:rth

e fit, tt~e more lik

ely th

at reducing

ccmd

ieio

n, ~t

i~i11

Ile enc.<>ur7terect and ~}'

~'~c

e.pi

•e~s

ent in tE7e }s

c>st

rac

k: t)

atsx

con

Tpil

e;cl

lly ~1iIler

car. a

I. for tlae fleekeIE~y 1

''it CEitsttc, 1.lcizitana) and the Lib

erty

Pit C\Y

-.hi

tc: Pine Co

unty

, NeYatla)

shon

~ pF

~ vitues of 2.8'anci 3.?

1, r(;

s~ec

tive

ly lie, Gu, and 7

..n cc

~nce

nrra

deu~

.s greater l3ian

5(1

Fr~~

,`L;

azx

i s~

tlta

t~ t

ireatc;r than 3jU0 x

~~~~

'L. S.-uurazion

inci

c;x cale:ul<rCir~ns for cater

in. the

~3cr

1.E.

tcy I'

it sllowc:d t3zat t

h.e m3rze~als I~c.rrtx~drite, gypsum, ju

i•banite (_

AIt~H`i4): 7, :end

j.~'osite

C~'~

,[S(

:1.j

17 1.C

~i11

,,) prcaviile

srilut~i.(i[q li

mits

(~>r th

e ci;ssolveci coa~.stitu~nts unclear {colic

etxn-.

diti~ms.;~

In c

.~as

e5 w

tze[

c~ r

llr

capac:iry

crl th

e sy

stem

is 4

u1'f

cie

~it to neu

tral

ize

aci~

t geiterttion,

else pH values are »a

r dej~res cd.

1~<~r ~sainpte;, in

ttLe Ial<es at

the

I in

l~er

ly Pic (W

hite: f

ine.

t;ou

nty,

l~c

.vad

a) and the 5

cru[I~ P

it;

G~~t

eiel

l ~l

itie

(nc~rtliern 'veva<la), the

p~-[

~~a

lues

are

?,67.

a~ld 5.1&

; respectively.z' Elevated s

i.il

.£at

e: c

c3nc~ntratii'ms (>7.~t~0 m~Il:) surest t

Yi t

sulf

ide

mirier:i!

ttxidtttic'~n

is o

cc~:

in-i

.ng at Chese~ si

tes,

}:7ut, in aen

esai

, tn

eCal

s c~ncen[rati~iis

art; nc~t sigrti$cantls

~I~:

v~zt

e~ l

~eca

i.is

c: al

tlae i

c'~~v

sc>lak>il.it}~ of the

ir m

iiter~is and

;'e~

r ll

i~li

-ac

is<r

;~~t

ion

a[~finity at

t(iese near-~zeYatsal pt~

~-a

hies

. He

:»~-

e~~c

r, a~~~enic i of

}~at

enti

al concern

i~r the more ~

~e:urral l

:tl.e

ei~vircmrs~E~nts l~c

•~au

se i

t is

less

str~

ngl}

r ad

sori

.~er

l ac

Ili~;li ~

I-I

(>l.j) tki

ar~

i.En

rier

aciciir. <:crnclitions. At ehe

L:ieec~licil

~1in

e. -the

arscr~ie co

ncen

Crdt

ion

is I.Q

tirn

~~, gr

eate

r in

tl~e

hi~;lic;r

~~I.

t ('.

(i'}

~;i

nth

Per.

lak

e than in the

a~~u

cli Pi[ la

ke (}7

t'~ = >.9

G}.

~icl

d-ln

zpa

terl

.Ncr

larr

a`.7

.rtk

cas

Lzrk

es slc

>w~~

c~~i

ru3

c>F coal,flrc~d power i

.~ls

tnt~

aaxl indt[ tri

es that bum stclf~tr-contain.in~ cc

ial

<an became a

tidi

iied

by die

int

rodu

c€i.

<5n

c.>f acid-~:ia~tucinh ~

,ase:; ~

pa~i

ilri

halt

y SQL)' r

ota

C LC~

CH[M

IS"f

RY OF ACID MINE Wr~

CI'L

~r

y3

In areas wP~

eze zhe nci~tr~lizing caF

~aci

ty cif cl~

c s~

rste

m is

suf

Fici

ent,

the

pii

aP

tl~e lak

e.gi

ll n<

at he de

~rre

sse~

i. I

ioc~

-cve

a•,

iz~ 'the no

ntic

aste

rn LniCect

SCat

es where th

e na

tura

l.nc

utra

lar~

tioi

i ca

~ac;

ity is

I<~sv hec

acis

e of the lack

caf'

earbon~ite .initieral and r~laTivcly hg

i~na.tua~ai or

gani

c ae

ici

ccante~nc of iunoff, thi

s additional ~

tic:ic

l fi

~om

aano

spii

erie

elcpt~sition

msiy

ciegress Che I~H of the t

ake.

Por

exxn~p(~, ac ~%~c~ds Ike (ti

ew Yt

~ek:

? th

e .a

cidi

cpreci~itatiW~~ I

z:~.s

~l m~~n F

AH c

if 3:96 and the-pH of the. .

lake

. eiur t

c~ this anthropc.>genic

{ciciic ci

epoS

iCic

m is ~

:U.j

'The face

cif sui[ate in sua

•fac

c v.

ater

mar-also have <in

impact on lake ac

idit

y. ~ul:fate

n3av

lie

tred u~ in th

e seciimeziGs as org

anic

5 cc>n~pciuntis ~cr

red

uced

inorganic S, In :z

study of ci

~l7t

atilt lak

es in ~?ucuec~, Ga.rign~n end Tessier'? Faiipci tha

t the: majarit}~ of t}~

eantkirc~p<~gen a31

1c deri~•ecl e;~cesS y w•as tied ~i~ in the sedimeaits as re

duce

d in

carg

anic

rzo

nmi

ne~:

ats :

sutai as

FeS ant

i ~~

yzit

e. As sho~~n by Rea<:t[on 12-15; tlae r

eciitetinn c

.~f Fe(IIT) ~aml

SOS in c[ieseclimeiits by as a

ntic

matt: r; asf

acal

itat

ed bys

iafa

te-r

educ

ing la

ac-~

e~ia

, pr

oduc

esno

t ont}- the, ircu~ sul

fide

. ni

inei

als lout t~ic~sk~onate i

ts solueic~~Y. ~~iciit c>n

al sLt

lfat

e-re

dtxc

in~

reac

cic}

ns p<>stut~tecl

L~}° Carz~nan anti Tessier are

as fw

llow

~:

$CHz t~ + 4S0?- +ZO z ~ ~iS

~~s~

+ 3I I

C;t) i + 4~i ~C~

(12-

1')

9'GH,O+RSd-~-

4Fe{

t)I-T

~,i~s

~+2(

3~--

>4Fe

a~~s

~+1G

HC:U;+'1~HZ t~+CC~~ (12-.18}

Iz~ each ~a~t

zt~e reciu

cdon

aP one- mots csf st~]fetc; ~~i

oclu

ces:

twt~ m

crfr

„y of al

kali

nity

~s

represented by HC

.C~ ,The bic

a:rb

aaia

ce ~ar

aluc

er! sn the

tie

dini

ex~t

s ca

n pa

rtic

ipat

e in acirl

i~4u

tral

izat

c~n

t~~--the

fgll

r>~ting retctibn:

FiCd~ L H" -~ H;C;O~

C12-

1))

Herlihy et al.'R ac

1sc> She

~~~e

<I tl~~t fcn a lak

e in

Vtr

ginu

t t6aC receicecl a~i

ct iniate dr

aina

ge;,

the; major sin

k .tcaA• :i

ron acid sirIf'ate zuas

J~acterial sialPate re

duct

ion and t

[~e Precipitaur>n

cif

FeS in

seclinients. As lon

g .~,

5 tY

ie.s

ulfd

e minerals are

stable in tl~e

reclucect condition of

tli~

sed

imen

t ar

c! sore no

t rei>xi<lize~'3, th

is crtechanism Ut c:ic;ating neucrali-ri~~g caF

~aci

ty w

ill

.tie

effective.

Iz1 soSrlc, 4

~ctinients Carignan and Tessier Fou

nd tl~

ac die' P

e{TITj ~;eserve a~~ailat~le

fc.> f

<.~r

n7ir

on sul

fide

miner.+ls «ga

s .nearly ar com

plet

ely ex

haus

ted.

'These lak

es will le

ave a Inwcr

ca~a

ciiy

r.~ tie

utr~

z~ x

ei~t inp

ut throu};h the ~i

roee

ss of su

lfat

e re

duci

ic>n

and. t>

ir..

ubon

ate

prociu t

ion.

Ire

takes with

less

a~•ail~ible i

r~3n

ir: is mare I

ikc;

Iv t

hese

the si.dFur in

sediiitents

mill he con

tain

ed in

orgs~nic 5 cgnipaunds.

T'he

pre

scne

:e <

~f leidic co

ndit

iein

s in. s

urfacY; lu

ster

sho

uld no

t alb-ays b~ ate

ribi

ited

to

anth

rop<

~~en

ic p

nllirtants. In

a stu

dy- <tP th

e fa

ctor

s eantralling

acidity in t

he. Rz

ver

Lil4

an;

nort

her~

i Sweden C

pii = 5

.18)

,. Janson anti Tv

aix~

~n3~

found tha

t the

acidity in

_'>

$ sm

all

trib

utar

y st

ream

s to

the

: river

~~c{~ ca

tise

ii p

rincia~ally

b~~ naturally occurruig

c.>r

~ani

c acCcls.

The c

liss~>tr-ed

or~;

anir

car~an

ih nu~st

i.~f tl~e s

f:re

:~~m

s ~~

acie

d between 1Q and 3~ m

gfI.:

During periods of ~~instcirms the pre

cipi

tati

on flushed cx~an c acl

<ls From f

lee Br

est

~c>i

lsaid 1puerc:d tYie.

p~-I i

n th

e st

ream

s fi

~om

G.5-?.0

era /.

>->.

0. T

'hc~

mov

eixi

ent of h

~ianic

I.,i

p arvof Cpn

Arca

s 6l

ntuW

ging

•imP

u6li

caUo

n Da

ta

l.:meiiIDir,'AaDaliL.

...l

queo

us rnvironment

ai gea:hemir¢y ! by Don

nid.

Langnmir.

p. <nt.

(ncluArs indcz.

ISBN 4~C1^_-3b741.-1

I. WaG

^.r chemistry. 2. tin

cimr

menc

aT~e

ikhe

mist

ry.

]. 7i

lle.

SS i.

43~ a'k

2t

9(i37GC4

CIP

E.ee

<uti

ve ed

ii.e

r. RoM;r~. McCy

naai

n

Pnxluciiun: t

3TP!iarrison

Ccgr

y editor. [iT

P Harcisnn

Cnvc

r dircc~nr: J

ayne

CGn

ir

39amiC~cmrin; managcr:'P~udy Yisciovi

Cs li)97 by Fmni

icc~

Haii

,.(n

c.~i

mau k Sc6

asie

r? A Viarnm Company

... l;

'ppe

r5nd

dle Rietr. Nco•lrncp Oi45&-

Af 7 righir irx

r~vr

rL N'd

port <+f t/is D

ank muy by

~our

odua

vd,

it

rv,j

r~m or Cvmy mrr

ois.

~vir

l~uu

t per

auis

.crb

rr inw

ri;.

n~,g

,,~i

anrt

he puG

lish

er.

Printed in

the Uni

~ed States of A:nrric;~

IU

±3 $ ? 6 5 A 7

ISBN D-02-367452-1

Prem:icc-Halt In

tern

atio

nal tUK) Li

mitrnl, Iz%

nrkm

Pren

iice

~~Ha

ll of Australia Ay. I.

iinited; Sydncti

Prcn

!ico

-Hal

4 Cunmda.inr.., T inrzrn

Yren!ice-}Iall Hispan~azneri<aim, S

:A.,

Mexico

Vrentice-Ha!4af Indic Private Li

mito

~k, New UeU

~i

Yr;n

ticm

-Hal

l vi

l:~xn, tn

c, te

tyu

Simon dt 3c

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er Asia Pte Ltd.. Singn~om.

-

k:di

mra Pr

cmic

o-Fl

aU du Btaeil, L:d

u. Xio Jr

Juariro

Contents

Preface

v~~

1 Thermochemical Principles

1i:

l Some BasirDe6nitions and

Cen

cepc

s t

i? Enthalpy artd Entropy 4

1.3

Gibb

s Free Ene

rgy.

Che

mica

l Po

hant

iai.

.und

c}ic

Equilibrium Constant

71.~1 Equi66rium Cal

cnle

tinn

s 1O

L41. Pur

e Solids end Liy

uidx

aad

'fie

irlN

i~iu

rts 10

1.4.

?'Ga

ses 15

1.4,

3 So

{utz

s t7

1.4.

A Soirem Wacer 1S

CS Summa ion

of Reaction-Theanodynariuc

Properties

18l.

6 The Etf

ecto

fCha

nges

SnT

empe

ratu

re and

Preasure onihe:Egnilibrium Constant

19

f:6.1

Intr

oduc

tion

19

1.43. E

tfa~Y of

Temp

eret

urc :0

1.6,3 £ffsct of

Pnssure 2&

Stud

y Questions 32

7'robtems

33

Chap

ter

1 Appendix 38

2 Cfiemicaf Kinetics.

50

2.1

GhemiculEquili6riumand

.Che

micx

ilKi

netS

aGon

cept

s 50

..2

Elem

enta

ry and

Overall Reactions 56

2:3

Data saws 57

2,4

tiff

ect o

f Temperatare on Rcaotian

Rate

w 60

2S.

:~Sincra] PrecipitatinnlDiswlotion Reaction

Kinetics

6~1

2.6

Absolute Rut

s (Tr

ansi

tion

Stare] T

peor

y~an

d the Ac

tiva

ted Complex

6'

29

Some Kinetic Examples of Genchemicai

Interzs6 63

2:7.

1 The Fe50q Camplez CH

2:7,

2 Ra

dioa

ctiv

e Uecay: The fix

ampt

e oC "C (i8

'?'3 Oxi

dati

on of Or

gani

c ~l

atre

r and Sulfate

Rednc~ion 70

2.7.

4 fypsum Dis

solu

tion

'71

2,'. S Qxi

dati

on of Pe

rtqu

s Ir

on ?

2.7.

6 Yy

ri~e

and Mar

casi

te Oxi

dati

on by Fe

rric

Iron

73

2.7.

7 Ca

lcit

e Di

Ssol

uRor

t and P:ecipicuGon i3

2:7.8. Si

lica

Polgmorphs; Uissuln:ion, and.

Precipitaci~n

7+1

'2.7.9 5iiicata In

cSud

ing fe

ldsp

sr .Di

ssol

utio

n,and Precipitation 75

2:8

Summary Observations

78

S`tu

dyQu

esti

ons

7y

Problems 79

3Aqueous Complexes

82

1.1

[ntr

oduc

[ion

and

Overview

E2

3.I,

1 Z)

pter

v'an

dYnn

ervS

phef

e Complexes 84

3.1.2 General Ob

serv

ufio

naon

Com

plex

aeio

n HN

3.2

Metal Ca

tion

-Lig

and.

Reln

ti~n

~ in

Comp

lexe

s E3

8

g Thermochemical PrinciplesChap. T.

Se

c. 1.3

. Gib

bs.F

rae:

Ene[gy,.Chemical Pot

enti

al, and the Equilibrium Con

stan

t 7

SOU

a~ tiw UU

i.b

3.5-

3.4

33

32.

'fempeaaWrc. (K?

Figure 1

..1

I..ow tempera:vrc heat ap

acit

ic< of mus

coJi

tc ~KA

IZ(A

ISi3

O~o)(OHh] a

ndpprophylfite{AtzSi3O~~

(OH)

.7. The

hear c

spuc

iry in

.}Da

les p

er moledegree (

7/mo

l K) di-

viiluJ,hy d

, t R4 e

qual

s the

heat ca

paci

ty in

calgries pe

r mol

e de

gree

(cullmoi K).

FrumRobie

et. ai

. f 19

7ti).

The

tlti

rcl-

taw e

ntropy of s

ubstances usually eq

uals

zez

o at'l'(K) = 0. A p1o

F of ih

e.me

asur

ed hea

t cx-

pacity ofthe min

eral

s mu

scov

ite an

d pyropfiyllite is sht

iwn in Fi

g. I.

I. To determine dS~ for

etid

ier

minerlt, we in

te„m

~ate

the

ab~vefugctiun bel

ow-t

he emp

iric

al'c

urve

from 17

[o TtKy (S

ee Wood and

.

Fras

er 1)76; Nor

dstr

om and

Munaz (99

4.)

7'I~

e entropy <i

E dis

sole

•eas

peci

es.i

s approached qu

ite diffen.nBy: W

ecannoi know` (an

d do vo

t.

need

to know') th

eir a

bsolute enV~pies. I

nste

ad; we

cons

ider

the di

ffer

ence

s in,S (

rn• ~S)betwezn

aia

aque

ous sp

ecie

s and .h

f* iw

i, as

suming ST far z

he H"'

(aq)

= 0:

Trea

tmen

t of th

e thermodynamic pr

op-

cities cr

l' aqueous s~cies.is addtestied in more det

ail l

afeb

:Entropy is a mea

sure

of t

he de

grr.~ of ran

domn

ess ai

disorder of a pha e (t

betr

nai,

.seat s

ticat,

or the geo

meai

.c ar

cang

enie

nf of the at

oms,

far e

xample}. The mpst or

der e

xists a

C0 (K), wh

ere S.

= ti

for iiiost substances. nth changes of

. state fro

m so

lidt

n fiquid togas; th

e ent

ro~y

.inc

reas

es dis

con-

cinuausty wi

th inc

reas

ing disorder of th

e ph

ase:

Thus

, for H2O ac 2$°C

S° (ice

/) {t

hetascabfej, <S' (water) c5° (steam)

Cl.~

i

10.68

< 16:72

< 45J7 ca

lfmo

l K

(Fur fur

Q~er

useful eniropy re

fere

nces

see

. Krausk~~~f t967; Lewis an

d Ra

ndal

l 1961:. 1No

ua :md

Feas

ex• t9?6: Sta

mru an

d Mr

~rga

n 1981.Hendcrscsn f9&2; Mas

on ana

Mi>

ore 19

$2:3

'

L3 GIBBS FREE ENERGY CHEMICAL POTENTIAL,

AND THE EQUILIBRIUM CONSTANT

The Gibbs fr

ee energy (G;

y of as

ubst

¢nce

i is

def

ined

as G, = H; — TS;.

Fre

e energy canna he

tt;e

a-sareddirectly. As wit

h eflthalpy, we consider th

e di

ffer

ence

(DG) be

tween [l

ie tree ene lie

s of

sutr

-stancee in

are

acti

on. TGe dG for

a re

acti

t~n is the maximmn ene

rgy ch

ange

firr c6n

t rc

acti

un as us

e-tu

lwor

k, mes

ksur

edat

cnnstanctemperature and pre

ssur

e. For a re

~cti

oo. we can

wri

te

"This i

s a mos

t im

~+ci

rtan

c. fun

dame

ntal

rel

ati<

insf

iip.

Next

. wa wil

l show hok• ~1G ° is

. rel

ated

to th

e. eq

uiti

brim

n coustan[ f K

~.,{) Cor 2 rc

acti

eii.

Con-

side

rthe

general re

acti

on

wher

e th

e Ip

werc

ase Ie

tYer

s denote th

e nu

mber

of mo

tes of

reac

tant

s r1 a

nd B an

el pr<x€ucts C an

d D.

11ie

USbhs fr

ee ene

rgy of

a mo(e vF.

9 at. som

e pt

essn

te and

temperature is

L,,.

"Chi

c is als

o the de

li-

niti

on of'

tfie

.che

mica

t potential o

f'A, qr

GA =µ~. w'

e can al

so write

wher

e T is

in de

gree

s K, an

d aCn is t

he standard mo

lar Gi

bbs fr

ee energg

<~f 1. ~G;, is the ~;i

hbs

free

~en~

rg} of

A at uni

t ac

tiv [yoYA (when (A~ = i)

. The

activity of

,4 cap borough y cho

ughr

ot'as

the fraction of its t

otal

con

cenl

rati

cm [f

iat participates in re

acti

ons.

Pur fun

s the activiey o4'

A is

iisu~

aEly les

s tha

n its c

o»ce

nu-a

tion

. (Sz

e Ch

op. 3)

.Fo

r u moles of

A, uG,q = c+

,~G;$ + RT In

[.9J°: Now ~r~ fo

r the genertd re

acti

ur eyualc th

e di

~-ference in the

sum of va

lues

for

the

pro

duct

s mi

nus that feu

the n:

ac[a

ii[s

DG, = cG

~•: t dGn

-- aG;

~ .... bC

,~

(7 J 9;

Cnao

duai

ng exp

ress

ions

frmUte ether re

acti

ng.s

u6st

ance

s similar ro th

at for

A, svc <ibt~iin

.~Cr=[c.9G~+ilc~ro—uaG~—b~GNJt-RTIn(C~`+RTin(,13j''

~I?0

— RT

In(A

]~~ —RT In

~6p'

Coll

eeCt

ng and

comhining terms

~A~~~a

~,,

(t._

whue aG

,°, which eq

uals

,tBe

bmcke[ed di

~'fe

renc

e in te

rms iAi the pre

viou

s eq

uati

on, i

s the

stamdard

Ciit

ibs f

ree e

nergy of

the reaction. The ra

tin of

conc

entr

atio

ns nn th

e right maytse called the

reactioir

quot

ient

: ~J.

At e

quilibriwn ~G, _ ~ an

d Q = K~ or

or si

mply

0G° _ —RT li

p «~ ~t

~~,;

(1.2?)

[A 1"

tB3°

QG,9 =—XT' In Key

(1:? i)

.Activity Co

effi

cien

ts of Di

ssol

ved Species.

Chap. 4

Sec. 43

.Act

ivit

y Co

affi

cien

ts of Io

ns129

128

etectdc co

nsta

nt is d

etermined b

mwsurin~ the

ca a

cita

nce o€water, ~;

; ~e

rsu,

tlia

f crf a v2cuuni..

3 a 56,E~i

~ 1

.1 67C9~.~,V

d 56

89i1

),.

P'

H:U'

.S

G Ei t

--._—.----I

~~. M E _ ~H nl~ .

~ -- ~ — ~ ~^

Toe term n

is tl

x, zf

fe t

~ve size <~

E the

hydrated ron in an~stronrs (i A - I nm = IO 5 cm) an

d~ ~

~ I

~ "

j

is a fun

ctiu

i~ of the de

rta i~t hydr~non of th

e ip

n, whi

ch is rnnghly propaniunai ro

ns ;onic po

ten-

-~---'-

~.r.~

=~~

--.J~~f

~ 1t

ali~

tsch

:rcg

e. ovacradiusr(seebeLgwJ.GiveninTa5le4.tureaoncizepa~maetzrsf2mmanyfn~r-

~ ~

~ ~

- -

4 4

~ camc and orgtroic t

ipec

ies based ch

iefl

y qn Kie

llun

A (1

9271

. lccording to Ki

ella

nd (19

3 <j a;

val

ues

` I

~ ~

~ Fe

r m<~r,anic imis ran

ge tzo

m ''

.~ to 45 fir mrn

iova

icnt

ions, (excapt

i~~r

Li

Ind H"

): 4 to K for ci

i-

__.:. _

. _

._j.

._'--~~~ -- '~

~-al

enC i

ons;

4 to

9 fu

r tr

ii~x

lent

~~n

s. xqd

~. to I

I: for qu

adri

~~al

enr i

nn ~..Thranomai~ms size qi

the pr

o-,.

o ~ ~ ,? --

' 1

~ y~•

I. tun (~ = 9) reHe

e.ts

rts o

ccurrence i

n th

e lame hy

drpn

ium io

n (I~T~U) and

in ~mular hyd

rate

dape

cies

.~

, ~

~ Some ion

actn it

y eoe

the~

nts at ?S`C compiued

wifh the

Deb

ye-H

iick

ei equ

~tic

m vs

a fun

c-~

~ ____

~ tion vG io

nic st

rzn

th i

on size

and. cih:;rge. am sho

wn"i

n Tu

b1e 4.2. Detiye-f l

ucke

l im

p achy i~

q c~zi-

~ - ~

'. fiezentc up to ~ 1

moVl~~ ~nmc st

reng

th, a

re plotted in Fi

. ~.3 fvcsomemonnvalent and

di~ale«t io

ns.

~~K ~-'-"

~~

..

~ Tt~e Debje Hu~kel eq

uati

on can

Uc used tc~

com

pute

icc

urat

e:tc

li~~

ity co

effi

cien

ts k'or mcmovalznt

..

~ ~ ~

~. I ~

`.

~'~

~

na up to

abo

ut 1= 0.

1 ~tiollkg, f

or drv

aien

t ion

s to

abo

ut / = Q.

01 mol

;'kg

, anti for tr

ivad

eiv.

ions uF

>io o

eAlSaps 1

- 0 (?p1 mot

/kk

u., ~ ~ _.

;.~,~.

~-~-

'

. , k

1t tun

ic stn

.n t

l s ixrHcen{).401 and

(i.(H)Ol xno

I/kg

the sep

arat

e cu

rves

fur mdi~~Adn~l a ns of

~ :~

:~ iteo

:: ~

tiic carne valence c,o

nvei

~gz on

i s

ih~l

e curve: At th

ese low

ibmc.:;tEengths. the

[zr

m !3 rr;'~~! aP

-j

'

;

p c,

nd

the

D y

Hu~h

e1

;uon is reduced to

~ _

----

--~.

~ .,

~~.

roac

h ~c

zero-. ;t

eb .

. -

eyu:

..

.i

(4.3

(7)

a~ ~.._.._

~ :I

',

log Y•

- -A-mil

~ -

~ ~: ~

~ ~

! ~~., i

~ n

~ Th

ro as

. c,tll~d t

lxe DcU}c Hu~kcl lm

imn~

, la

w ~t

hig

i~er

ion

ic str

engt

hs, di

ffer

ence

s in

ion

. size, ia

,i

~ -~

oa:ues} Ee

coir

~c tmportanc ui~d c

ause thv

y, c

urve

s. fo

r individual wns io di

verg

a.~

- ---~-'- -"'-

'Ihe efF

ect of

temperature un io

n a

acity co

ethu

e-,f

c is

largely ~necli. f~

d be ch

.tnn

es in

lice

... .~-

_

~', ~'...'-"'-.`

-~

~~ I

~ ~! ~

S~

~ ~.

value af~{.. whi

eh.i

s proportional to-lu y: in

the

Deb

~e 13iink~l ey

uxti

on. The v i{ue of

.A inc

reas

es~T.

~

~ ~,~

_: S

~~

__~_

fmm.0.49? t

o 05

34:b

etwe

en.~

and 50`C '16

us,a

ctiv

m co

e.tl

icie

ntrb

ecom

e im itI

ery itlYAnoreaeing

1 __---~~-._"==---

temp

erat

ure.

Bcc

ause

2 is

mul

tipl

ied icy z- ~n

the'Uef>ye-Hiickc! e

yuaiioii. t

he c(fecr;~f tem~>erauire

~t'_

—~_~...-. --.:----. - -t"~--"-~~-

ra.

en ac

tivity cue

ffia

ents

l.>~

reat

est f

ori3

mlti

vale

ntro

ns.

h

.-_~

10 "

4

t .;

itng

ih lmo

l:il

i

~ 42

:3 Intermediate Ionic Strengths: The Davies and

~ ~

TruesdelWones Equations, Specific ton

-hKe

ract

ion

i~. figure 4.2 So

me individuel.lon

acti

~i~y

~thcient~ co

mENt

eJ fivm mran

salt

data asiuna~ng. er

e m8~ry

':i

~ '.

4ifu

:)ti

nCy Coni'C11ti4?~1.

t ~

~min

ati~

in of Fi

gs. 4

.1 aGsd ~:

2 sh

ows th

at ind

ivid

ual.

and

nte

an in activity cc

~f(z

cien

ts ~eA

~ern

lly

~;,,

use

~?f t

t;c t

heor

etsc

af 1)e

hvc ~~

t io

n, ~

tUtn

.,~u

ons ar

e P ~ ely~Cnuln ili c:

, icin size

vic

es not

~.~ry~~:`' '

~ -.ease rominimal values between

I an

d 10 mol

/kg,

and the

n increase at hzgher ion

ic uiz

ngtn

s~n~

vy ibi

s eq

u RS

yn incla~3~ th

'~:

. ~we

v~er

, the form of

the De

by~-

Hiic

kei egaatinii is

such th

at it

Uredicts y vah

ies th

at dec

tine

con-

iomc

sc:

~ngt

h, an

ct ions n[ th

a sa

me sig

n do

n9c

inte1a Zt v~i

~ in

chvi

Au.i

l ions the

ecNa

tiio

n Ati

`

~~cl

) tv

iA~ ~om~ stxeog2h. Sev

eral

aas

uix~

ptro

ns nc

gr~x

~rar

ed in th

e 1)

eby~

Huc

kel equwon be-

1oE.

y; _ ~. } ~; u y%r

- invalid za

d lead to.its Paiitve at~hi h io

nic strengths wh

ere io

n ac

tivi

ty coe

ffic

ient

mc

ie~s

e

`? ~

28 x l

l)` ~~

;2. ~e7

~'~'-.13 = SU

.3.(

el")

~r w

itb p, the density of wat

er E the

~'

wuz 1

83). Thew sss

sump

tion

ti ~nc

iude

: in

n interactions are pur

ely coulumbic. i

on ci~z

nor }

;u} with I, a

rid. io

nti of dte same sil

o tlo not ii

~ter

acC Ch

emic

al equiliHria ca

lcul

a[ia

as im

a whereA=~S~)

P~,=

f ater(1.U.7mo1/k~)ancliuhigherionicstm~tgthbrinesrequiiea..tivii±•coetticicntrrodels~~ith-

niC constant of water

and T m kEivi~i At 5'

C,

69yi07 E - 78:

4.52

5> A = O1509 , ~•

p ??$3 (Het

oa end

Krr

l ham 147

4)

The in

crea

tie in

'iti

n acu

~ ty u~ffTcientsat el

evated iod

ic str

engt

hs re

sulh from se

vera

l - ef

fects,

:1t other te

snSr

cr uuie

s th

e c:wleetnc ~~nsrant of wntet'can lx: o

btained from the

cqudtic

~ -'-

~h li

mita

ewra

+.

~'ng tha Fac

t th

at an.

iner

easm

gfra

cdon

ofw

atex

molecules are involved in

hyctrn[ion spheres

_- 272t.58(i + 0.

(}2241,Q

i T - 46

6.9151 In T - SZO(~•K7~T

~ ians.7'his causes a proportionite decre~asa in

the

u>nc

etit

riti

on o~ Y'

ree wa

ter molecules in

the

i 'il. fi

~u' £sample, assuming then5 a

te si

x tvxter vn

olec

ules

nssociater7 wi

th eac

h pa

ir of di

ssiy

lvec

l~

`~

ncl CI ions in a p.Ql mo

lar tT

3C1 so

fuda

n (s

ze Bockiis and

-Red

d 13

73

!fie r

c~ic:s f "

stto

m ~ ~1

1~11)9~) T~ ~~a~

elc a is taln

rant c

if water is

a mea rc,

of he et cue otswa~e (~r u

t

lium) ~

n deueasing th

e force f F) of

. the

elecvicel fi

eld becwe~n ionic spc+c.ies «s

solu

tion

~h'

y ),

n

tree

j ,.; :.

er' and

s~ ~n~

: , 3~ the

cti~rges on inns 1.

and 2. ~n

~ ~ ~s she

ili

stun

ce 6et

w~:~

~ tih~~n.

r ..

..

~ ~ ino

leru

tes in

a Iite~ of s~lupon rr

e 55.5'- (x-f

O.Ol

j= SS

.~t4: On fhe~other h.

ind.. f th

e sa

tuti

on

~."

~ ~

AcidaandBasas

Chap.5

156

_.__.._,_--~-g

i

i~. r

~.~t~}(

CU~~

C(

7=..

_~_.

5 I 4"6 7 ~

...._

t

045-

~)

~ ~

I

~@ ~

'I

~~

i~ _L--

—

K to

i2

0~y

r

~:~.

2 DistriUueion din

gram

for

carb

onat

e pe~ies usatuncuuaof pH:

acsxuming C:r=

of Cr+

are sh

own ~~ d:~

.hn«

'Fi

~urc

wh

ich

ire mdep~indenc

IIY*

:M. C

oncensrations of H* and

nH. ,

_ ..

....r

+.:

straight li

nes.

mtc+

ns are consumed in reactions [

hak produce ca

rbon

dio~ , ,~

1

the pH w

ill

rise, and cnnver5ely. Amnn~ the rea

chor

~~l pH, Remember that when fru

: p

3it~Vor carbonic aci

d (a weak d

cia)

, rate in bo

th sudaec~warcr an

d gxoundµ'a~er systems w6, -~-

prcitesses kilted in the

iabla..son~.2 ope

x:

otli

ers t+re lar

gely

tim

ifec

l to

one oc ~}

ie oche[:

~

'S'tie carbon liu

xide

content of surface ~+'ate~ t

o°ds

toward a lim

itm~

val

ua defined by N

~

d iiie CO_ pressure in tt}e atmosphere t~.(K~;C ibesses, iO

clud

rg (1

)~hrov=ft {9} n T. ~

r.

law .m

Ln

7 pr

essu

re reklect rel

ativ

e rates cif r

eacr

ions

~ and P

with SitUe sunlightpenetratia

$ume xuc

S~uc

e wa

ters

(dee

p, st

ratified, and

pgorly ml

xad,

aunt COZ P ""

}~•

ollu

ted}

arep

hys~

cail

yiso

late

Af'r

omt!

~eµm

uP"a

t~X~ee~ ~e ntm Sphe

n ~~~~ ~"

~`

wi~i

ch is de

fined by Pca

, -'

~ x

s

equi

libr

ium partly reftocts th

e {ac

t th

at the

rat

e of CO,, d+

%~ds

Sing

from Wat

zG is siowec ~~

~f gaseous cptake from the

acmosphese

tcf.

S~hmiermund 199

1'.~

fore

l an

d He

[ing

19

~

~-

et al.

t994).

ressures from about 10"

x'' t~ i~ ~ b~' So

urce

s of CO

'iin ~ t

s~ucly of Isskes worldwide L46

65 sam

ples

fmm 1839 lakes) Cole et aL (1994) four

~

c f

ront

aU9~

't 4 to

10 andCO_ p

. ~d r~spiraHon an

d de

coy i'elat~d to

- ; ~

rang-d

indu~ie it

s in

ftvw

in surface waters and ~co

un wa en

3 vx

}ya

rinl

ake~

~v~

raluction-aod a~cumuIanon ~

imen

tsan

dbio

ta,T

lteo

~era

llme

anCO

2pre

a5ur

~of1

.09x

10" ~~

o-"

~ tothsai

u ~.

greater than the ~tm

osph

exic

vaS

ue. Tiiis•. reflects a COz R

ceec

lsi~sr

aieso

fcon~umptioninthegrn

wtha

faqu

atic

plan

tsAn

drat

eofd

egAs

sing

P c.

~. «~

~ 3:3

~,,.

Sec.

~5.3

Carbon Dio

xide

and Carbonic. Ac

id Spec

157

TABLE 5:3'Some im

port

ant processesand rea

ctio

ns th

atcontrol tha-CO; content of

surf

ace -and groundwaters and, t

herefore, t

heir pN

Rrocesse5 an

d. rcac

tinn

sp1~I up or down

I..C

O y)dis~ol~xion

). C'

U3(~G

1 ~ti50IUllOR<—

—3C~OWIt/(—Li~3

CU t ) + M20 <-

a CC

> (aq) t tl

O H H

zCO

,°2.

I'hr

Nosv

ntUr

sis`

-~

re~pirntiur @ acrnUic di

cay F

-iii

p/mo

d<>w

nco

y ~~

~:oH

i,ec,,rz~.~nt~.~,

~a,w+

c~,

3. Met

h me.-terntentahon fan

,~er

ob~c

dec

a}~}

~-atlawn

CFH _ n (eluc~s ) -> iCH; ~F I

I O+Cn~

d. 7V

ivar~ up(.~kc.~nd i~

ducn

o».-

a.-pup

No +~tt~+2crr:c~-anti,°+zco,+a3,o

5. De

rntrificution ~

-auk

5(.'

ll n+dNU~+4H'` -r SCU

2ND+-13;0

6. Su

iF.~ie rcd

ucti

nn -~

yuE

~?C

ki O r

SO

-r H ->

2CO.+HS +

Id.;

O7,

Cap

1 une

tc mme

r.~l

dis i 4 non

-~ m ~ re

•ipitaric+ii i-

--iupJf-down

NaF3

C0 (na

hcoh

t~7

kT

~~i1

+FL G1k C0:

S. Common iun drnen ak

itcp

rcu{

+Gta

t~on

~~->ci,wn

Ca50 ~H,q ~~

2.H

CQ, -a

C.a

C(7 + SO;' .

'_E l~U+~O:

gypsum

calc

ite

9. Ch •i

rn~aiweatliesmg of

AI-s

iEic

att niinerat>

>up

2KAiS~,O

r+2C0 ~-I

IH_O

~>AI

,Si:

05 (OY

ti: ~i~'_K'+2NC;.Q,

K-feldspar

kaol

init

e

Vote

: CH U n.

~+re

scm

ores

i c

inac

rcx

'Uthxr r acnans ihatle~J in

c.iiixm fi

xd

iri rn

uy.~m<dse cp

enes

of S and

N (v

l' \1

orel

& H

i c~ 1943;

S~mn

m a.i

~S ~t

arga

n t9Nh).

Some ~F

ti7e

loti

~est

app

aren

t CO: pres

sure

s (an

d re

Fa1;

d Bi

~h~>

t pH

's)T

uund

in iak

c.s anS ot4

zr-~

:e

ti4alers result fro

m th

e ph

otos

ynth

etic

act

ivit

y of 5t

~uti

i~ ~z

geta

tion

(reaction 2->) aro

und

`~-,

rem

ovin

g C(7. fa

P ~r

iore

ragi~l~ than

Lean

He n~p]znished fr6

m-th

e. ~tE

mysp

here

G'cactioii

fi'o

m re

spir

atio

n an

d tl

ecay

(rea

ctig

ns 2t- and

3-j

), or from gcound«~ater inflow to th

e sur['ace

-~ (Gr

ound

wa[e

r5 u;u

ull}

• enntaiAi mire COQ than sur

face

a este

rs, j The highest pH's du

e. fo pho-

°~he

tiis

aze

found in streams, la

kes, and

resarvoirsrl~~Cecl vrithgceen algae (waters tha

[,ha

ve a

biot

aias

s/wa

ter ra

[iti

j:he hig

hest

app

aren

t CUZ pr

essu

res i

n sudacc waters may occ

ur at nigfit,-when the

dom

inan

ts ar

e re

spir

atio

n end aembic dec

ay (re

acti

on 2t-

), and

perhaps ~roundtcater inflow. $urh

~ '

is re

fleo

ted in the

dat

a ft

om a stady of ,Slab Cab

in Run, ncu

r Sta!tc Cpl

lege, PennayivZnia,

Cable 5.4 (3a

cobs

on ec al

. 19

71 j.

Sia

b Ca

bin Run is a sm

all stream Fed

by carbonate sp

ring

s^-logged wit

h phorosunthetic ayuaticwegetation.Tbe app

aren

t COi pr

essures for t

he stream

~ ~ '.

4 bare bee

n co

mput

ed from

the

to[at analysis usi

ng M7NTfiQA2. Ivt

etis

urem

ents

at

n n summer du}

~ showed a minimum stream pH of 7:

76 az

id maXimum app

aren

t COZ pres-

v e

~ , a

,ex yaz ~m6a51y re$

eeti

ng chiefly tha

che

mist

ry of groundwater inflow. At 2 a.

n~. th

utac

dre ph

~ros

ynth

esis

by uyuaiic veg

etat

ion produced a maximum stream pH of 9.42 and

" >i

kng reduction in die ap

pare

nt CUr pressure to 10"`" baz.

166

Acids artd Bases

'Chap

,,

Notathat the eyu

i¢al

ents

af ac

idit

y dae to eactx ca

tionic. s

gecias, n

t the

number of pr6tons it can

c;

Hate, e

quals th

e charge of

ttia

l species;

5.7 ALKALINITY

Alkxtiniey isthe cap

ucit

}• <>F

a Wat

er t~ ac

cept

protons and

is the sum effect o[ ~tCb

ases

. present.

most pot

alif

e wt

8ets

the a#k

alin

ity is due chi

efly

to 6i

carb

anat

e iaa an

d, ro

a man

or extent, ;a

rb~

ate,

ipri

. Cm l~

~n;Gre nik

alii

:ii~

~ is def

ined

as HCO~+2C0.'• Hy

d~vxyl.x-lien present (

usua

lly un

i~,

porta~~t bel

ow atiout pH L

OI, i

s. cu

lled

cau

stic

alkalinih~. The coritrentional detinilian of tok~(alkal~.:;.

ity (Gy) in eqA

., or mcg

lL. is

.

CS=HCC~+2CO3 +OH"-H'

(5.~

.t

ur, i

n oF

lier

wor

ds, C~ equals the

rotpPequivalents of bas

es min

us fh~

se oFu:ids..Other bases th

at ~:

: ~:

comribute to

total alk

alin

ity are th

e li

gand

s of fu

lvic

aci

d; or

ganic ac

id anions such as formate, F

pinnate, and

ace

tate

(cf. Lundergard an

d Kharaka 1990) and

bis

ulfi

de, or

thop

hosp

hate

s, am

mrn,

.<.

bpra

ti, a

nd sil

ieut

es, l

ikal

init

y is usu

ally

cap

arce

d :u

1 mglL CaCQ, ur meglL CaCO~. A its

aful

e.:-

vcrs

ion is t"a (o

r Ca) as nig

/L CaCO; - CR (or C,,) as mey/1, x 5.04.

Cn potahle wat

ers be

low ab

out pH $3. bi

carb

onat

e is osu

a]ty

the

onl

y si

gtii

fica

nt base. Si

g :-

bonatealkalinity in wa

terd

eriv

es. fro

m two suucces: (t) tlie

wea[

heri

Fig of

sili

cate

and

zar

bona

te m

-

aralx by

carbonic ac

id, S

oc exa

mple

2KAISi~Q8+2H~CO.a+9H~0=AIZSiyUy(UH}a+2K*+4HjSi0$+2}[CO3

(~.-

.:

K•fs

ldsp

ar

carb

onic

ka

olin

ite

silicic

acid

clay

acid

and (2) the dissolution of ca

rbonate minerals, whi

ch, i

f dissolved by car

Uoni

c ac

id, c

ontr

ibut

es tv

. ,

as much bi

carb

onat

e al

kali

nity

rel

ativ

e to

HZCO consumed a

s fines

silicate w

eatfiexin~

.`.~

exam

ple,

Cab~g(CO3),+2H,G0~=CaZ'+Mg?'+~6HC0.;

(~

dolo

miie

BSeart+onate ion

is us

uall

y th

e ch

ief-anon in ft

eshw

sier

s. In an

d on silicate ro

cks,

[he HCO~ c~

~,

canr

rati

on is usaally SU to 2U

(l m~t

C., to•hereas in grourid~raten dia

l contact a few percem cn~uq: >-

mlte

rial

s up to Foie lim

e sto

ne and

dolomite,. b

icub

onat

s levels aze usu

alty

~in ihe~ ra

nge ~f

?0~

~-'

40d ppm. Se

awat

er cnn

tain

s 1q0 mg(L HCO ;Ca

rbon

ate al

kali

nity

(G0

3")v

arel

y ex

ceed

s 10

m

!-

~Nliy?Tl~e presenca of cnustic al

kuli

nitg

(fr@e OA') at pH's above 10 usu

xliy

ind

icat

es ait

ific

ialc

taotiiiaitieii of a wa

ter by, fa

r ex

uny

le, Cn

(~E3

Yi fpo

rtla

ndit

e7 Pro

m the sexcina of'conc[eCe at

nc~

',~

comp

lete

d wells. C~, concentrationscan re

ach

1 WQ ppm as HCQj in swl

iiim

car

bona

te-b

icar

bo*

'=

brin

e.; f

ound in evaporarive, cl

osed basin lakes.

Foe naWml waters in whi

ch the

. onl

y ac

ids an

d bases are sp

ecie

s of carbonic ncid and

stn ~

~-.

acids or bas

es, thane is a simple relationship between G'a, C~

i, and

the torsi cai

twna

te. CT. Remz.

bc;r that the si

mpte

deGnitiuns otthese pa

rame

ters

are

.and

6'

n = F3C0~ + 2Gd' + OH" - H'

(-`' ''

$eC

5,g

Acitl•Base Pro

pert

ieso

f Minerals anA Rocks

167

gjge

brai

c rr

iani

puta

[ion

show

s th

at.t

hese

expressions arr related in th

e equation

Z~r=Cep '~

GAR

~5.~

{G1

5.8 A~~d'gASE PROPERTIES OF MINERALS AND ROCKS

\4os

t mi

nera

ls are sa

lts o

f w~

~1c ac

ids.

and s[

rong

b~.

ees,

'['h

e we

ak a~

;iiis i

nclude si

licic a

nd cartsooic

suds. Th

z st

rong

bases <i

re, far

ex2mple, Nu01~~, K

()f~

i, an

i~i C

.~(O

J~i}

_. F3e

cuus

e.of

thei

r weak aci

d-.

trong base cha

racE

ex, most mi

nera

ls ~re

sta

ble un

der al

kali

ne conditi~~ns. but l

end ru

dis

soiv

z ci

nder

a~yd con

diti

ons.

Con

sist

cnCw

i[h this he8uviur:.~e'hen ground-up ti

lica

tc and uluminosilicate min

er-

;ilt

i;ve

plac

ed in

pure wa

ter,

tke pH ~et

tera

ll}~

ris

es to al

kali

ne values. Su

chbeFiavior civ~,s mos

t ii

n-nctttant rn

c[cs and rninei~als (bu

t nut yu

urt2

, Sit7Z) n sultstantial alk

alin

ity that can neuri if

ize gntur~l

xcon

tnmi

nant

acid

ity.

The

rate

of s

uch.

nenrralizatinn is r

elac

ivel

y fa

st lo

x earU~nate ro

cks.

but slmy

,-~rmost si

lica

tera

:ks,

exce

pt the

clflys. The

neu

tral

izat

ionp

resc

ess is ca1

1u1c

fiec

nica

i we

athe

ring

ud ix d

ealt

with in tti

ore de

tail

in Cha

p. 7.

Typi

cal ee

athe

ring

rea

ctio

ns are she dissolu[ion c

~k ca

l:i

ce~a

nd the tv

¢ath

~rin

g of

pot:

isti

ium fel

dsPa

c ro.F<~r,'m kablinite cla

y (§e

e'fa

ble 5.3).

A fe

w mi

nera

ls produ:x ac

id when th

ey con

tact

water. These min

eral

s ca~~ be des

crih

ed as sa

lts

~f weak bases an

d st

rong

aci

ds. They chiefly to u

lt fro

m we

athe

ring

and

oa~

dauo

At of eh

e py

rite

or

+~ur

casi

cz (FeS;) exposed in tt

te mSning i

~f mineral dep

osit

s and cool. Suc

h aaQ mirterais, w

hich are

~.om

inan

tly F~'` su

lfates ~nd

To a'

min

or extent AI

D`' s

ul(':rks, t

y~iically I'

unrr

frUm the ev

up~r

xtit

in of

-Pol

ed aci

d-mine waters qr of

t3~e

m~ismre in

mt~arurnt~c! min

e wa

gCes

or s

poils t

iia~ eoi~iuin Qr

e st

d--.

Jes.

Acid

ity i

s pradnced when they are dis

solv

ed by kresh runoff'or rzcl~arge.. Fnr ex

aitrple

F~,t,SO.~I!t • AH,O = 2Fe

}'

-t- 3SOy'•"+~tH_O

(S.d

7i

+her

e n - 5 in

lausenite. 7 in

kom

elit

e, 9 in

pvacognimbite.and-. cogn

imbi

te, a

nd lt) in

que

iist

edti

lc?a

lucf

ie et

al. 19

5.1'

): Tci

dity

is produced by hy

drol

ysis

o£ the ferric ir~m,

Fe"+3H;0 = Fe

(OH)a(PPt)+3Fi''

{S.~

R1

'~Qore common niinerats in

such a sating ar

e jar

osit

e and alu

nite

. which of

ten.

diss

olve

inc

on;r

uene

lyIo

nn Cheir ozyhydroxides; re

leas

ing prorons. 'f

he ja

rosi

te eeaction pr

oduc

es sig

nrfi

canr

acidity,

nere

fas a

[unite is a

very weak ac

id. For

the.

reac

xign

KPe3(SQ3)z,{OH),;+3Hz0=K

*+3F

t;(V

II);(pp

t)+2

50,'-'+3H'

(5.4

9)

jarosite

icy'- ~h

~.~~.SQn-~~~.}{+~3 _ jQ-19.i

(~.JU)

.s'ummg that X,p

= 1D-'

0 far the ferric oxyhydroxide and K,~

(azo

site

) = 10-~' . and

green ~K

~ moi ;

g, aa

ci [SOq']= 10'2

~s moUk~; and

.ign

orin

g ac

tivi

ty coe

Tfic

ient

s, thepH f'o

r eq

uili

briu

mt jar

osit

e is

3.8

.The pH at eq

uili

hriu

rn with the aJumimm~ t~~

!f~t

e salts nn. t

he ether Band, is Pea; ne

utra

l 1~'

cir

unit

e9n ec

iuil

ibri

um wit

h amorphous ~luminwn hyd

roxi

de, t

he rea

ctio

n is

KAI~(.Sf),~)Zi01I)~+31I;n=K*+3Ai(OH),(ppt}a-2S0;-+_~I3*

f551}

alunite

which. K~

I(Y' R-', ass

umin

g K,n

~= I~

-}5 fo

r th

e alucnimrm oxyhydrnxide and

K ~{a

luni

te) -=

cs.z

. Ag

ain

give

n IK"] - i(Y

' m~

illk

g, and

(SO

<-f -:1CY"as m~Ukg, and

ignoring ac

Uvtt

x-coe

ffi-

nts. th

e eq

uili

briu

m pH i, B.

R.

3

4

3 i i

352

Adso

~pti

on-D

eso~

ptio

nRea

dion

s Ch

ap,~

~

TABLE 10.5 Me

asur

etl ca

tion

ezcfiange capacities; in

situ ~oik pH values and

porc

enta

c~es

of ma

jor ex

chan

flea

bte.

ions

of some so

ils at

pH - 7

Soli

pkI

CEC

F,yi

uval

ent Percent

1~{

K

Na.

Ca

of GF.

G.

'v1g

Mn

Mot1

'iso

n s.

tndy

-S

3 4

ill

3

33--

.`~4

1:8'

Iciam wb

soil

~5 ftdeptfi)

i.nnnusoil

3:6

1~7:

~3~

7 2

148

16

—

(;alifomia so

ils

7?0

.?—

6

366

'6

—

I{olllnd soi

ls7

3:2.

3—

a 6

?9

13

—

vlerecd c

lav loam

i(1

13:9

D i

95.

0it

—

Note: U

ashe

s indicate nn available d

ata.

$<tw~r,: Pr

nm:G

rim N9

(Ri.

l4'i

k!un

der (

.I9G4). anU Ap

v nd.I.ang!ruir~i9 i1)

Give

n in

Tab

le 10.

9 ar

e me

asur

ed. to

tal CEG ~atnes fo

r some s<»Is, s

lung with th

e eq

i ,.,

,,,.

}xrc

zn[s

of diffen;nc ad

sorb

ed cations mai

;ing

up the ezchan~cable GEC and

comespondin~

i ~ ,

17ie

CIF:(: v

n.tues rep

oA't

ed in the s

oils li

tera

ture

have usual ly hcen mea

sute

d ut

pH 7, Fi

gure

s I t, ' ,::~

10.5 show eh~

e GEG values fo

r rhex~xides and kaoliniteare a sCron~ Functiorra#'pT3, so that

ulcerated at

}~I~I 7 for these phases is an se

riou

s er

ror if

assurnud for ~tUer pH'

s.. Fot:ttte be

ntc~

.~~

,

smectiteclxy)and tUe

itl

ite,

sur

face

cCi

argc

Ss relatively independznt of pH, wthat t5e

CEl

i.::~

stu~

ed at pH 7 h1i Tr

toc~

e general value..

Nuts the

rel

aiiv

c ca

rc~n

[r3t

ions

oEH'

ion an

c~of

hero

nfio

n6 aap

~rd~

aU of rhe.c'ait C

P,C.

._~,

in Table f

U.:i. l

axi~

~ort

ant ions ad

soib

ed on sails, l~

ucrarely mea

suru

i, may inc

lude

'3H;

, an

d

ter(uageii soi

ls nuly al

snin

clud

e Fe

=" and

Mn='. The da[a'in Tab

le'1

4.5 show cha

c'.h

etow

sbou

V I ?,

pAnt

ons a:cupy x lar

ge fr.

icti

im bf

lap surface

sites': Below pH ~ [a 4, pro

tons

occ

upy

all t! _

...

and te

nd to de

stro

y clay tiveturds. This, of co

~xrs

e, makzs t[ d

iffieulCro study the

surface a~.

~ .: c

tint kiropesties of -l

ays in aci

d solutions. T'he p

i4ta

n competes eft

ecti

yety

w.i

di oth

er c.¢

iunt

_,-

chan~e si

teti

, even ~~hen iti co

ncen

n'at

ipn is lQ to

1.(1

~ tim

es 3e

ss than th

at of Use

clfion,

The knt

al CEG ~aliies of so

ils re

flec

t th

e va

riab

le: cun

trih

ut ons of oE

ganic mlgei; cl

a;

als, and

fxrcic acct 4Ie

oxp

hydr

oXid

zv. The h[~h CGC 9f naeural organic m3ttet (

,fiu

mic s

ubs.

whic

h is

typ

ical

ly between.I SQ

~to 3Q

(7 tne

g110

0e; el

enve

s fr

0an

its ~

:arb

oxyl

(CO

OH),

gt~u

ps.

• _.

.

depro[on:i~exitliepHofmostnatural-~yaters(T'fkuc~nan198~),~'het~ighCECveluesforwatu ;; d

soil

s. flip

to 15

meq/t(H3 ~ forNew Jersey pa

ils,

acc

ordi

ng toTuth an

d Qtr 7 y7D) ptvb

~ lily rest

is ~:

~ '.

it~eir hig

h organic colifents. Tlie CF

.0 of sa

ils is tenerelly 5ishe,¢t in the

A t

~~ad

B hnr

szon

-_

humlc suU

stan

c~s an

d clays ate mist abt

rnda

nY (7'

i~um

aan

1985}. Apgar and

L:angrnuit

- .

meas

ured

CEC values of 0nf

y t~

,few

rne

yAll

X) g it

t G-loo„xizdn soi

ls in

' centtal PennSylvama

--

soilsorganic mat

ter v.

-asa

bsen

k .md clays such as kaolini[e and

ilJ

ice made np abom ' eo

-

~

l~:C

.5U1

1. rticcording to Toth an

d Ott (19

70),

aboa

c 8U n pf the C,6C:: pf:modem riv

et and eSr

~a~

-

_ -~,•

anenis is

due

to Crash' or

gani

c matter. These ant

hois

f6u

nd that sc~iments from the

Deluw.0 ' ~~” ~'

Chesapeake I

3ay,

Gmd: $amegaE Bay were 2 to ?4`m o

t~,a

nic matter and

had

a mean ~

. ~-i. -

~t

$7 mey

/10K

) g. 0£ th

is mean C;TC; prg

atuc

soi~bentc con

trib

uted

~1 meq/lOq ~.

;. an

d in

arga

'~-.: ~-

'.-

bents

t b meq

/1(7

t7 ~.

1n s~ilsand in

bonomsedimenls ass

ocia

ted

~,~i[i

~ streams andothersurtace-waters

tt~a

~ - ''

liioh~

at fqr

tine-g

rain

ed maieti;ils, and

dec

r~~.

~es r

apidly wit

hine

reas

ing pa

Rici

c, site

s. F3oc

~-

(t98R} reP

oa tine fg

po~v

in; CE

C'va

h~et

i in mi;g; lOb g [or di9Yerent soil-si

ze ranges: san

d.

Sec:

10.2

Sorption Iso

ther

ms and the Distribution £oefficient

353

TABLE.10.6 Cat

ion exchange cap

acit

y an

dtim

e for 50% exohange of K- ont

oMa

ttoi

e-Ri

ver sediments of

increasing siz

e fro

m cl

ay to~

fine

gra

vel

CHC uiginic

Tcnai CEC

fraction

'lime

for,

<.0°

:r.

SAze

t'ragioR

(melllW g)

(mcyllUO _y

}ex<hm~ue

CIaY lam

? F<~

~)53 to

3R

q7 to 3~

5i G~

.:3 c

Silt (3 to

6? fim

)lf

3 to (

i~ffi

tip (i

? to 5 s

Sand

(U.(X tc~2mm)

8u7

7S w6

$to 3A00s

Ffn~ gra

vel (

2'tn 9:i

mm)`

Sao 5.4.

'?.4

~n 6

R.IG

.(NX

) 5 (?

' hY

Snun

Uutn5~nnrpfairnlm an

d Kr

n~xa

ly ('

:97Q1

undc locun,.2_i tn, ]7..l;Joan~ ?.S tci

.(5:

9; sil

Floa

m. 9.4 to 263; and

cla

y a ndday-loam, 4 to 57

.5.

~'~i~ h~ntto

le Rner sediments, Kennedy and

Mal

ceim

Q977) observed

that

cla

y -sired

mate

rial

s-2 um) ha

d n CF

,C' of i8 !v 53 meq/1(70 ~.

The CF,

C of f}n

e gravel ('

_ eo 9.i mm) rznged fro

m 6.4

$ meq/1G10 g.

In x surrey

crf U.S, st

rear

m sc

dime

nts,

:~Ke

nn~d

y ('I9fi5)cuncluded. th

at fhe

m:~

keup

and

prnp-

:-ti

es of tf

ie ttreatn sediments essentially equaled that ci

f la

ce[ soils. [n

8i~.easlerr sinter (SD to

50 cm precipitation), dc~

mina

rr clays in th

e <d µin (O,

Ofkl

mfn

) Pi

ncii

cin we

re it

lite

, kuo

lini

re, ve

r-

-~ic

ulit

e, and

inteciayered cl

ays,

with a CCC. of 14 tq 28 rt

iegT

t p0 ~.

'Tncentrnl and

west-cenvaP ~t

,ues

to iQ0 em precipicution) Kenpe¢y~ tnu

nd ¢om

inan

t.sm

ecti

te,v

enni

cali

te, mixzd-la}•er il

li[e

, ka-

15;r

a, au

arV.

,. and

I`eldtpar in th

e <4 fun.frtction. wi

th a CEC' range of 2z ro 65 ine

q/1 ~

JO g. In Cal

-nw and

Oregon, bec

ause

of the wid

e range of ~i

~et and

diy

ccmditibns {<?j to ~ 2(KJ

cm pi~

acip

i-ion). c

l:~y

were highly v;

~iab

le,.

and halo range ot'

CL•C

's Pram

f $ to

65 meq

/lOf

~ g f'

or tlx

e.4 ~c

m.f

icti

on.

The rat

e uf

.ztt

ainm

en[ of ~uilihkiam in exc

hang

e, ceai

;tin

ns is f

astest wizen clay -sized materi-

are in

vo]v

ed and

~;urbate in

ns c<

in die

ecti

y cn

ntac

c surface si

tes. in

lamer

-sired mac

zria

ls, i

nclu

d-v roc

k fragments an

d in rack ma[rix, ho

wera

r, th

e areainment of acisorpubn equ

ilib

rium

is l

imit

edthe mu

ch. slower ra

te cif di

k'fusion of sorbing sp

ecie

s in

[u and

oar aP nic

k po

res (cf: Jenue 199

5),

's point is

illusUated by

the mevurements ofMalcolm and

Ken

nedv

(I)7

U1, wh

o,tu

dred

the

.rat

eca

.h&n

ganf

K' tun by di

ffer

ent size~fractions of:4taCinle.Riverrediments using a pate slum-spe-

~~c S

on ete

ctra

de. T

heirresuttc ar

e summarized: in T~bie

L0,(. C'

ompl

etc exchange ;uok

f ti

t 2 Mays.

fie £negavel. Su

c1~ effeMs aze als

o impariant i

n ft

aeWr

ed rt

>ek where most groundwater H ew an

dat

e lransp<~rt o

ccur

s. in fra

ctur

es;.

but diffusion ci

f sor

bine

'sol

utes

fi~om the frac

ture

s iiita ad

jace

nt- ~.:kmatrie takes pla

ce (cf Skagius;ind ;Veretiiieks-19

$R: Sc

hw;i

rzen

bach

eh.il,.1993).

~~~'

- ~~)RPTIQN ISOTHERMS AND THE DISTRIBUTION

COEFFICIENT

~~~ 2

.1 The Freundlich Adsarpxion Isotherm and the

Distribution Coe

ffic

ient

Kd

generally observed that as the conczn~ratio~ of a spe

cie in sol

ario

n in

crea

ses,

the amount of

itred (at

tach

ed in same wny) to

cen

[acd

rtg so

lid (sertxnt) s

urfaces

alsri increases. A pla

t that dp-

.ces the amoant of a sp

ecie

s sorbed tthe sorbau~) as a fw~ction of it

s cuncentr~ti~n in sul

urio

n,°'gored at e instant temperx[ure, i

s cal

led a soc

p[io

n isbthetm, i

1 simple so

rpti

on isoihenn Is Shawn

i

3

r,

356

Adsorption-~esorptionReactions

Chap

..10

-cV

sediment ci

r may be solids tha

t have p

reci

pita

ted,

such as m

etal

. carbonates. and AI

, Fe

(,CI

I), and

..

Cain

{IY)

oxyhydi~oxides. The tra

ce elements may pr

ecip

itat

e. in

their own puresolids, but

most of

ten

are co

prec

ipi[

ated

as tr

ace specifies i

ii the

maj

or element so

lids

: The K~ app

roac

h ha

s been use

d to de-

u;ribe t

1ie ren~ovat of trace ~L

eme~

ts from sohnion by ail

~f these me

chan

isms

com

bine

d. Suc

h a

Jumped process app

roac

h is sti

ron~

ly das

cuu~

aped

in th

at resulYant.K~i vu3

ues only describe Th

e be

-.

havior of th

e system in wh

ich they wer

e me

asar

ed..

Ass

umi~

~E a si

ngle

K~ val

ue 4qr

predicting th

e ta-

tnov

2l of a dissolo'ed spe

cies

from

strean~:s, so

ils, and groundwateis,usuatly lea

dsto

serious e

rrnr

for:

specizs th

at form swag com

plet

es, p

recipitate in insoluble solids oc aresubject to oxirlatiim oz re-

duct

ion.

Lumped-

proc

ess K,~ v

alues (

apparznt Ka s) for s

uch speci~:s can

vary nonlineady by many

oi~d

eiso

f magniwde between. p

H. 2 and 6. (See Fig. LQ.

B.)

When K,

~ value, dominantiy;aRect a sc

~rpr

ion process, iE li

as been found th

at tog A~ gY

'ten e~

aric

~c

tine

arly

with pH for at le

ast se

vera

l pH units. Far

example, mea.4un:ments. bztween pH 31 and 4.6

reported by

o'an dei

Weijden and ~-an. Leeuwen (1985) lead to Io

g Kd (m Vg

) =-1

.073

+0,$

27$.

pH.

(r = 0,

993)

for man}•1 acisorptipn by pe

at. P;n

decs

son et

al.

C1982} have tep

oxte

d lin

ear l

eg Kd ver

sus

p}[ plots f

oe Gs* and Sr'* a

dsorption

try~

ea num

ber c

if ig

neous tacks an

d minerals bet

Weeq

pH 5 [0 11.

When a con

tami

nant

spec

ies of interest is

alrw

dy present in

[hes

oil or

groundwater, i

t is h

ighl

y

ircoinmended that th

e w:fifer a

nd suit be sarctpled and ana

lyze

d:ft

u th

e cantuoiinant to de

terr

nine

an

in srt~r X,

~ val

ue, Thi

s is. a

fter

ntl,

the KR e

ve :¢

e in

tere

s[ed

in.

Its v

:il~

e ofteixAififers sUb

stan

iial

iy from

a K,

~ mea

sure

d in

the

labarat~ry. For

ezam

pie,

£ruc

htex

et al

. (1985) r

epor

e res

pect

ive Ia

bora

tnry

K's

of 356

0, 4Ob,

and 19 mU~ fa ~'

~Co.

~~Ru and

~-SS

b. Res

pect

ive in .s

itu K,

~'s'

.for

these radionuclides

u~uated 9;

(i, and 4; indi

cati

ng [h

at,rn fa

ct c

tiey wer

e reta~ivaly mob

ile in the. groundwater T'he au-

thore point ou

t th

at the

laboratory

K,~ s were measured in noncomplexin~ el

ectr

olyt

e solufions,.

whereas in the

fret

d the

;adi

oiiu

clid

es wer

e co

mple

ted,

proba6lyb~~ organicsubstances, maki

ngth

em

less lik

ely to

be ad

sorb

ed.

The best ns

e.of

K,~ i

s probabiy w rnodel the sorption of tr

ace molecular or

gani

c sp

ecie

s such

as pes

tici

des,

or ofher weakly sorbed no

nian

izet

3 or

gani

c sp

ecie

s, The adsorption of dis

solv

ed ma

lecul3r or

gani

c su

bsta

nces

by so7

s and sediments ha

s been found to ba proportional to

the amount

of'satid org

anic

matter present and

elatively in

depe

nden

t of th

e we

ight

of as

soci

ated

ino

rgan

ic ma-

teiials. "C

hic ob

serv

atio

n, whi

ch is pa

tt cululy tme r

c soi

ls tha

t co

ntai

n Q.

1 to

2070 or

gani

c ca

zbon

(cr". Lyman et at. 1982: Thurman 19$$1 Sch

wazz

enfi

ach et

a1.1993),has ]ed

Co th

e concept of

the ad

-

sorp

~ion

or di

stri

huti

on coe

ffic

ient

for

org

anic

caz

bon or Kx def

ined

as

;ccg

ads

otbe

dlg or

gani

c C

(10:4

K«-..----

--

pglm

t in

sol

utio

n

The weight ratio o

f total organic matter to organic ca

rbon

ranges from utw

ut 2.O

in so

il. fulvicaei

ro 2.9 in fimnin (,Schwaraenbach et al

. 19

93).

Assuming av

erag

e: or

ganic ma

tter

`is ap

proz

imnt

eiy

CH~Q, the weigh[ ra

tio is

2:5. T

hadzs[ribution coe

ffic

ient

for or

gutic su

bsta

nces

sorbed.6y to

talo

r-.

gznic ma

tter

(K~m) is the

n re

late

d to Kx by K~ = 2.5 x K m. Val

ues of

Kam. rang

e from 1 "t

~ 10' ml

/€

of nxganic carbon. Example K~ val

ues (in

mil

g) Tor some common org

anic

con

tami

nanu

, including

pesticides, are: benzene, 8

3; at

razine, 1

6~; Ii

nJan

e, 1080: in

alac

hion

, I80(I; pua

thio

n, 1.66 x 10'

.

DDT. 2.

43 x 705; an

ti muex, 2.4 x 1Q~

(Lyman et al

, 1982}.

for n;

gani

c so

rba[

es, t

he dis

uibu

eiva

cozf

fici

ent Ka is

relatzd to K,~ through the ex

pres

siu .

X,~=Kok x.f

(1

_

wher

e f,,; is

the

weight fraction of t>

rgan

irca

rbon

in th

e se

dime

nt. F

requently K,~ values hav

o ~'

"

peen

measured. K~x is,

hnu~eeer, n3at

ed ro other im

port

antp

rope

rtie

s of

u;g

anic

substances. in

s. ~

'~-

a~t

5 K

i ~ ~

o:l

`

~ _ 6

Arx

Nigu

reld

.8

Lumped•pmcessilisiribuiiortcciefficients(K,~'s)forsomeniemenesmeasured

duri

ng ]ub

prat

ory neutraiiz56an of

aiid solutions with ca

lciu

m cs

dx>n

atc (T

aylo

r 19

79).

Thes

e K~

val

ues re

pres

enot

he com

bine

eief

fect

sof e

lement rem

oval

s by adsorption, a~

pre-

oipitation, and

/or pr

ecip

itat

ion o

neo a

nd in

fre

shly

precipitated Fe(lll), p1, and Mn(I~'j oxy

hydr

oxid

es and

Byd

roxy

sulf

ates

..gs

suc

h they are system specific and cannot be assumed

[o ap

pfj~ to ot

her s

yste

ms undef di

ffer

ent c

onditions or

having d

ifl'erent c

ompositions.

t ~

r c

~ 1

-- z.

t '

'. ~

357

~, ~

~ ~

r'. .:,

~ -

. ,,

.~ 1 i~.~

;

.~•- c ,

~

--..__

T.

;;'~;;

~~ 458

Iran

and Sul

fur Geochemistry

Chap. 12

ferrous ir

on is releasul to solniinn.'i'he sro

ichi

omet

ry of The ox

id;~

ticn

.Gal

P re

ac[i

~n (I q.

[123

3j)

su~,e~sts th

at a mole of pyr

ite shcwid prc

~dnu

c If

i prntons. However only th

e campIcte oxidatirn~

reac

tion

, which mu

tt inc

lude

an nxidaz~n

j ent, cs

sn pro

vide

Us with a valid rea

ctio

n st

oich

iome

Uy.

Two pos

sibl

e over ~!

I rectos reactions are

I'eS2+zO,TH:O-Fez'+2SOa.+'LH"

(t23)a)

r-~s

,+ra

N =-+~H n

> i5~

E +z

so, +iex

(iz~

yb~

'lli

us i

f Oq is the

oxi

disi

ng want ~ moles of H are pr

aiuc

c,d by 1

mole

cif p}rrie Lrc

onne

st bxi-

~da

~tr n 6y Fe;*releases 16 moles of pr

otons for e

ach mu

ic of py

nte. Obi ia

usly, ~

[ is e

sse~

Ual ro

k~iuw

whic

h re

ucSi

on dominatzs in a~

~y att

empt

to predictttie ac

id-g

ener

aRng

.cap

ac.i

ty of a sy

st~hn.

,..

°tThe nzzt st

ep is t

he c~x

icla

tioi

inf f

'emons to tu

nic ir

on. The rate of

ikie

Fe'

*(py

ri[e

oxi

dati

on rc

.~

.,ac

tion

is,

in fau, l

imited by fh

e availability of Fe3

'-, which itself dep

ends

.00:

[he Fe

(II)

cixi

dati

onta

te:

^~ k,Bc

lo~v

abo

ut pli 3 the

overali:Fe(II} o

xid2tion reacfion is

~'Fe='+'-~0.,+41`-a Fe

' +~H2O

{12.40j

'

~.,

1'he

ikrot c ra

ts of th

is rea

cuon

is slo

w. Thy pH of st

ream

s and groundwater th

at have move away

fm~n t~urce py

rite

suda

ces m r

e.~s

es tx.cause. of pa

nill

neutialiratioaby cac

bona

tean

d silicate mia

-

er11s. Above rouahiy p1

13 ke

~~idatiun is

the

n iievcribedby the

ove

rall

reaction

~}e r;.,-~p+:H,n->Fe(4H).;+2H'

(12.41

-"H•

hic6

has

a me tha

t in

crea

ses rapuily wnh inc

reas

inn pH. (See

.kin

etic

s Chap. 2.)

Ab~o

tie oxittatian kinetics of

sul

fur and Fe(

11?.

The ah~

on~ oxie3arionsates of pyri,,

and l~

uous

iro

n hlve`becn sa

idie

d eztenuvely kor mor

e tL

~aix

30 years (4F Car

rels

-rai

d Th

omps

oc~

i

#1960; McKibben and Bab

ies 1986; Ni

chol

son e[ al

19fS8; Mos

es: and Herman 19)I )

. The ti

vork

r .~

ctpyrite-c~zidari~n kinetics has

been up

date

d and crinyued by Williamson and Rim

stid

e (199A), Nhi

VF'e

hrli

(19J

0} ry

as syn

thes

ized

the' published data u

ia Fe=

oxi

dati

on. (See al

so King et

al, t995.)

~B~.se~1 on

sta

tise

ical

ana

iy~i

s of

published FcS. oxidation-

rare

:da

ta and -th

eir own w

oe'•

..

~ k

.-rt

e`~`~'iltiamsnnan~'2imstidt(I)94)derived[hreeempiri~alratelawexpressions,w•hece_r=d(FeS

2p,r

,I~.

..f

~ >

~ss the

rat

e gf

pvri

te destnaction in mnl/m- s.

From pN 2 ro

10 when ozy

~en is the

only ox

idan

t

t h ;

.,pe

rhap

. ab

ove th

e ~Y

uter

table in sp

ciil

materials or co

ar,e

€ra

ined

tai

ling

s] th

e ra

te la

~ti i

s~

I

}~

4+(m0

.

T.=(~D~R.

I t:~t

7Y1}

~+}t

l.11

ti^•j'

~

t Y ~ '~~

Be[w

een pEi 0.5-t~ 3,0, when F~,

." is

the

oxidant and.oxygen is

abs

enC (

conditions tha

Lmig

tri be

e ~-

`~" "~ "`

}pe

cied

rn an wcid groun~iwtuer or in flcx~dea-mine po

ols), t

he. rat

e ~ua[ion is

(mFe° jn:

w+.=(lS1 °s

ad_

(,i2.A:

..,r~~.

(mi'ia

+boa. ~mH?)u;3>

:

H ~':.,

[n the

sam

e ac

id pH ran

ge, when O2(ay

) is. pr

esent al

ong.

with 1

'e'*

, the ra

te is given by

(mFe,

)u.v~.

~rw

.(IQ

...n

.m~

._

_.~

GnPa` : }iron

The latter conditions mi

ght he fou

nd nea

r c (t

uctuating water [ab

le ~r wi

thin

the

capi

llar

y zon

she ~a

~ate

nabl

e.'I

'he yu

cca s of

WilViamson and Ri

msti

df's

model ti

ts to.puhli$hi;J axp

enme

^ J`

. '~ _~

;;'

~.;is

evi

dent

from Fig. 12.20. Re

gard

less

~.if th

e oxidant, th

e.py

rite

6cea

kd4w

n rate iS

see

n to

b.

~ ~-

Sec.

12:3

Iron-S

ulfu

r Redox Che

mist

ryi ~

-SA

_s5

~ _~.o

~ ~).S

~ ~-ie.o

-I~5

-I1D

`~,

c

~~

`p

L.

'-.I

I.O

-1

0.5

-Iq.(I.

-9.5

-9.0

-tl.5

-~k.

q -6 -5 -a -3 -2 -i

-ip _g

._g _y _2

~.l

Jos r.

ttu~ui

Limp,

Iq¢m

Fi

Y' _~

. *

i

°t

i~.~

_.

~G

_~.

m~

7

_~' -~~ ._~

._6 _4 -2. ~ -(

4

-'<

0. -..

-2

-I

itu~r,-innlet

6~,n

Knuu

~'n

hKui

itx

~. xy~.

459

-~~ ~ii -6 7 8

yeen iw

nrn~lxr ~ ~ —~ ~---~ I—.___~

iGPure nav~m tm

aphc

re

'p

i~

I . ~

[L

~,

~

`

*~

i

-

3 ..3 -2 -3.R

-'i.

4 -3.f1

..'§<m,

In~m

p,

Rigu

re 12.26 The rate o(

nxid

utio

n of pyrite (r = d(FeS:

)IAI in.

mul

lin=

s7 nev ?5'C and

7. Ii

ii pre

ssur

e. Nhole mnAe! and lev

erab

a pl

ots far

mu1~

i~,I

e li

ner ragreision nnulvsis of

pubh

shet

l and meawured is{e d.

itn fur ~hr uyuwus oxi

dati

on of py

rite:. (s) Oxid

atio

n of pyrne

by dissolved ox; gen: (h) Oxidation oP pyr

ite 6r tcr

ric ircn and t nn ~, am~n

sphc

re. un

d.(tl O~

idnt

ion.

ni p~n

re by Ter

ris imn in th

e presenec of di

sscil ul~oxygen. Reprinted 2

'rar

nGe

tirh

iin,

e7 Cn

srnr

thin,. Acm Sb M. A. Adliamsan and I, U, Riintindr 1n~. iinciics

and el

cetr

oche

mica

i ra

te-d

eier

m nm ue

p of

aqu

eous

pynte oxi

daii

an, 5

4x4

~ <~

79g

4.with G>e

rmis

si~~

nfro

m El

sevi

er Su~

nce Ll

d.,.

2tic

Baulev;u~d, I-

amgford L,

vic,

Kitilingtan

(1X.

i IG

B, U:K.