I R Y BOARD

ECOLOGICAL EFFECTS OF NON PHOSPHATE DETERGENT BUILDERS

REPORT TO THE

OF 'THE INTERNATIONAL JOINT COMMISSION

ON THE

ECOLOGICAL EFFECTS OF NONmPHOSPHATE DETERGENT BUILDERS

FINAL REPORT ON ORGANIC BUILDERS OTHER THAN NTA

FROM THE

TASKFORCEON

The Research Advisory Board effective November 22, 1978

ECOLOGICAL EFFECTS OF NON-PHOSPHATE

became the Science Advisory Board. DETERGENT BUILDERS

JULY 1980

NOTICE

Statements and views presented in t h i s report a re those of the Task Force members and do not necessari ly r e f l e c t the views and policies of t he International Joint Commission or the Great Lakes Science Advisory Board.

INTERNATIONAL JOINT COMMISSION GREAT LAKES SCIENCE ADVISORY BOARD

100 OUELLETTE AVENUE, 8TH FLOOR, WINDSOR, ONTARIO N9A 6T3

J u l y 21 , 1980

Great Lakes Science Advisory Board I n t e r n a t i o n a l Jo i r i t Commission Canada and the Un i ted States

Members o f t h e Board:

The Task Force on Ecological E f fec ts o f Non-Phosphate Detergent Bu i l de rs i n p a r t i a l f u l f i l l m e n t of i t s r e s p o n s i b i l i t i e s f o r meeting i t s Terms o f Reference, hereby submits i t s f i n a l r e p o r t on organic b u i l d e r s other than NTA.

Respectful l y submitted,

I L Y

( Jfseph Shapl'ro (Chairman)

&zxs- Richard Dick

& R Q O W ~ Charles R. O'Mel ia

ahsa& Anne Spacie

ACKNOWLEDGEMENTS

The Task Force i s indebted t o the Soap and Detergent Associat ions o f Canada and t h e Un i ted States f o r t h e i r assistance i n p rov id ing a mechanism through which cowanies i n te res ted i n organic detergent b u i l d e r s could coordinate t h e i r e f f o r t s t o provide in format ion t o t h e Task Force; and t o t h e governments o f Canada and the Uni ted States f o r t h e assistance o f t h e i r research personnel.

P a r t i c u l a r thanks are due t o D.R. Rosenberger o f t he I n t e r n a t i o n a l J o i n t Commission's Great Lakes Regional O f f ice; F.A. Brownridge o f Proc ter and Gamble Inc.; F. Kennedy o f CONOCO; K. Kaiser Environment Canada; and J. Welch and W. F a i r l e s s o f t h e U.S. Environmental P ro tec t i on Agency.

Appreciat ion i s expressed t o Proc ter and Gamble, Monsanto, Lever, M i les and P f i z e r Conlpanies f o r t h e i r major assistance i n prepar ing techn ica l reviews and responding t o the many queries o f t he Task Force; a l so t o those members o f t h e industry, government and academic community 1 i s t e d i n t h e appendices who con t r i bu ted through presentat ions and discussions o f re levan t in format ion.

Thanks i s a lso extended t o those persons who provided c r i t i c a l t echn ica l rev iew o f t he d r a f t repor t . E. Mones, V. Lamberti, A.W. Maki, G.T. B l a i r , K.C. Plunkert.

TABLE OF CONTENTS

P a g e N o .

INTRODUCTION . . : . . . . . . . . . . . . . . . . . . . . . . . . . . 1

. . . . . . . . . . . . . . . . . . . CONCLUSIONS AND RECOMMENDATIONS 3

. . . . . . . . . . . . . . . . . . . . . . . . . . AQUATIC CHEMISTRY 7

. . . . . . . . . . . . . MICROBIOLOGY AND BIOCHEMISTRY OF DEGRADATION 1 5

EFFECTS ON MANAGEMENT CIF MUNICIPAL WASTEWA'TERS . . . . . . . . . . . . 2 7

. . . . . . . . . . . . . . . . . . . . DEGRADATION I N THE ENVIRONMENT 4 1

BIOLOGICAL EFFECTS . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1

. . . . . . . . . . . . . . . . . . . . . . . . EUTROPHICATION EFFECTS 6 1

APPENDIX

. . . . . . . . . . . . . . . . . . . . . . . M e e t i n g P a r t i c i p a n t s 7 4

'Terms o f R e f e r e n c e . . . . . . . . . . . . . . . . . . . . . . . . 8 1

M e m b e r s h i p L i s t . . . . . . . . . . . . . . . . . . . . . . . . . . 83

INTRODUCTION

This r e p o r t o f t h e Science Advisory Board's Task Force on Eco log ica l

E f f e c t s o f Non-Phosphate Detergent Bu i l de rs i s t h e second i n a ser ies . The

f i r s t repor t , publ ished December 1978, deals i n i t s e n t i r e t y w i t h t h e organic

b u i l d e r n i t r i l o t r i a c e t i c ac id (NTA). Th is second r e p o r t deals w i t h t h r e e

o the r important organic a l t e r n a t i v e s t o phosphate -- c i t r a t e , carboxymethyloxy-

succ inate (CMOS), and carboxymethyl t a r t r o n a t e (CMT) .

The Task Force was c rea ted because r e s t r i c t i o n s on detergent phosphates

have been used i n c r e a s i n g l y and r e s u l t i n re leases t o t h e environment of

a l t e r n a t i v e m a t e r i a l s used by the detergent manufacturers. The Task Force was

d i r e c t e d t o examine t h e a v a i l a b l e i n fo rma t i on on t h e eco log i ca l e f f e c t s of

these a l t e r n a t i v e s and t o r e p o r t on t h e i r eco log i ca l s u i t a b i l i t y . The terms

o f re fe rence g iven t o t h e Task Force by t h e Board are appended. The Task

Force was c o n s t i t u t e d o f s c i e n t i s t s and engineers se lec ted f rom those

techn i ca l areas t h a t address known and p o t e n t i a l environmental e f f e c t s . These

areas inc lude aquat ic chemistry, m i c r o b i a l degradation, wastewater management,

b i o l o g i c a l e f fec ts , and eu t roph ica t ion . To f a c i 1 i t a t e improved awareness o f

unpubl ished data and ongoing research being conducted by i n d u s t r y and

government, l i a i s o n members were s o l i c i t e d f rom t h e Un i ted States and Canadian

Soap and Detergent Associat ions, and appropr ia te f ede ra l agencies w i t h i n

Canada and t h e Un i ted States. These 1 i a i s o n n~err~bers are 1 i s t e d i n t h e

appendix.

The procedure fo l l owed by the Task Force i n i t s eva lua t i on was t o request

the' 1 i a i son members t o arrange present a t i ons by i n d u s t r y and government

representa t i ves . I n addi t ion, t h e a v a i l a b l e l i t e r a t u r e was examined by t h e

Task Force and i t s members were assigned sec t ions t o w r i t e based on t h e i r

areas o f exper t ise. Sect ions o f t he r e p o r t i n d r a f t form were c i r c u l a t e d

among t h e Task Force members f o r rev iew and comment, and ou ts ide techn i ca l

rev iew was obta ined f rom government and indus t ry , and i n some cases f rom

se lec ted exper ts . Those who p a r t i c i p a t e d are 1 i s t e d i n t h e Appendix. The

f i nd ings of t he Task Force on the th ree organic b u i l d e r s are presented i n t h e

f o l l o w i n g chapters, f o l l ow ing t h e Conclusions and Recommendations.

Throughout t h i s r e p o r t t he assumption has been made t h a t t he b u i l d e r s w i l l

represent a maximum of twenty- f ive percent o f a detergent product, and t h a t

average i n f l u e n t wastewater concentrat ion f o r a b u i l d e r w i 11 thus be 12 mg/L.

C I TRATE

C i t r a t e i s a na tu ra l product which i s biodegraded r e a d i l y by many

organisms under aerobic and anaerobic wastewater treatment condi t ions, and i n

t h e natura l environment. High concentrat ions o f Hg(I1) and C r ( I I 1 ) i n h i b i t

i t s biodegradation. No in format ion i s avai 1 ab le on removal i n physicochemical

treatment. When c i t r a t e i s present i t can i n t e r f e r e w i t h p r e c i p i t a t i o n o f

phosphate by f e r r i c ch lor ide , alum, o r 1 ime. C i t r a t e concentrat ions expected

i n t h e environment are safe ly below those known t o be t o x i c , e i t h e r

c h r o n i c a l l y o r acutely. Use o f c i t r a t e as a b u i l d e r i s l i k e l y t o have no

d i s c e r n i b l e effects on a l g a l populat ions except i n s i t u a t i o n s where heavy

metal i n h i b i t i o n o f the algae i s occurr ing.

Based on t h e above and on t h e evidence presented i n t h e Report, t h e Task

Force be1 ieves t h a t the use o f c i t r a t e as a detergent b u i l d e r w i l l no t be

det r imenta l t o the environment. Indeed, o f t h e th ree b u i l d e r s considered i n

t h i s report , c i t r a t e i s the most acceptable. The group recommends, however, .,

t h a t t he f o l l o w i n g aspects o f t h e behaviour o f c i t r a t e be inves t iga ted more - .

f u l l y :

1. i t s a b i l i t y t o s t imu la te a lga l g r o ~ t h o r t o change a lga l compet i t ion

by che la t i ng heavy metals i n c e r t a i n na tu ra l waters. This should be

s tud ied i n systems l a r g e and complex enough so t h a t t he r e s u l t s o f

a lga l compet i t ion and a v a i l a b i l i t y t o herbivores can become evident;

2. i t s in ter fe rence w i t h the chemical p r e c i p i t a t i o n o f phosphate;

p a r t i c u l a r l y when chemicals are added e a r l y i n treatment; and

3. i t s removal dur ing physi cochemical treatment.

CMOS

CMOS, which does no t occur i n nature, i s biodegraded by severa l

microorganisms prov ided s u f f i c i e n t t ime has elapsed f o r acc l imat ion.

Degradation r a t e s are slowed s i g n i f i c a n t l y by impairments o f wastewater

t reatment operat ions, 1 ow temperatures, or low concent ra t ions o f d i sso l ved

oxygen. Such c o n d i t i o n s might cause l o s s o f acc l imat ion. A number o f meta ls

a l so i n h i b i t o r prevent degradation. No i n fo rma t i on i s a v a i l a b l e on i t s

removal du r i ng physicochemical t reatment. No i n fo rma t i on i s a v a i l a b l e on t h e

e f f e c t o f CMOS on p t e c i p i t a t i o n o f phosphate. CMOS concent ra t ions i n t h e

environment would be below chron ic or acute t o x i c i t y l e v e l s and CMOS does no t

bidaccumulate t o an important degree. CMOS i s u n l i k e l y t o increase a l g a l

abundance except through i t s poss ib le a b i l ity t o form long-1 a s t i n g che la tes

w i t h i n h i b i t o r y metal s. Under such circumstances a lga l species composit ion

migh t be a f fec ted .

The Task Force be l i eves t h a t t h e use o f CMOS as a detergent b u i l d e r i s n o t

l i k e l y t o be de t r imenta l t o t h e environment. However, be fore i t i s used

broad ly on a l a r g e scale, severa l issues should be i nves t i ga ted :

1. ' t he degradat ion o f meta l chelates o f CMOS and t h e acc l ima t i on p e r i o d .. .

necessary f d r t h e degradat ion t o proceed i n a wide v a r i e t y o f

environments;

2. t h e e f f e c t o f CMOS on dosages of chemicals used t o p r e c i p i t a t e

phosphate;

3 . t he removal of CMOS du r ing physicocheini c a l t reatment o f wastewater;

and

4. t h e a b i l i t y of CMOS t o s t imu la te a l g a l growth o r t o change a l g a l

compet i t ion by c h e l a t i n g heavy meta ls i n n a t u r a l waters. Th is should

be s tud ied i n systems l a r g e and complex enough so t h a t t h e r e s u l t s o f

a l g a l compet i t ion and a v a i l a b i l i t y t o herb ivores can become evident.

CMT

CMT, which does no t occur i n nature, r e q u i r e s extended acc l ima t i on per iods

be fore b iodegradat ion occurs du r i ng aerobic wastewater treatment. The

acc l ima t i on pe r i od i s prolonged by lower temperatures and, i n t h e n a t u r a l

environment, i n es tua r i ne cond i t ions . The microorganisms i nvo l ved are

f a s t i d i o u s and r i q u i r e b i o t i n . There i s no evidence t h a t b iodegradat ion

occurs under anaerobic cond i t ions . D i t a r t r o n i c acid, present as 7% i m p u r i t y

o f t h e bu i l de r , biodegrades i n an e r r a t i c and incomplete manner. Removal o f

t h e b u i l d e r dur ing physicochemical t reatment i s l i k e l y t o be poor.

Concentrat ions poss ib le i n t h e environment are n o t l i k e l y t o be t o x i c t o

organisms, nor i s CMT l i k e l y t o increase abundance o f algae. However, it

might a f f e c t a l g a l species composit ion.

P r i m a r i l y because o f t h e d i f f i c u l t y o f biodegradat ion, and t h e u n c e r t a i n t y

o f t h e f a t e and e f f e c t s o f i t s impur i t i es , t h e Task 'Force cannot endorse t h e

use o f CMT as a detergent b u i l d e r a t t h i s time.

AQUATIC CHEMISTRY - . - . - - . -- -- - - -. . - . . -. - -. . - - -. -- . . -. . - - .

INTRODUCTION

The dominant ~hemical, characteristic of organic detergent bui 1 ders, and the principal reason for their use in detergents, is their ability t o form soluble complexes with polyvalent metal ions. Re1 ease of these substances t o the aquatic environment can alter the forms and amounts of trace metals in natural waters. 'These effects on metal speciation may in turn influence the growth rates and forms of phytoplankton. The extent t o which environmental quality may be affected i s expected t o depend on many factors including, for example, the biodegradability of the organic chelator. Observed effects, b o t h

in laboratory and field experiments, are diverse and in many cases apparently in conflict.

EQUILIBRIUM CHEMISTRY

Some representative thermodynamic data for the three organic builders, c i t r ic acid (C6H80,), CMOS (carboxynethyloxysuccinate, C6H807), and CMT

(76% carb~xymeth~ltartronate, C,H607), are presented in Table 1. Based on .,

these data, the proton transfer and metal complex forming capabilities of these substances are similar. All can donate three protons. All are weaker complex formers than NTA and EDTA. All exist predominantly as unprotonated species at neutral and a'l kal ine pH. Because these substances are unprotonated i n the pH range of use with detergents (pH 9 t o l l), they can be expected t o require a second builder t o provide buffer capacity in most washing . .

appl ications.

CMT contains about 7 percent ditartronate, which has four carboxyl groups

that can interact with protons and metals. This substance thus has different proton chemistry and hence different buffering capabilities than carboxymethyl- tartronate. I t should also have stronger metal binding capabi 1 i t ies than the other organic builders considered in Table 1.

TABLE 1. EQUILIBRIUM CONSTANTS ( - logK) OF ORGANIC BUILDERS*

*These da ta a re f rom severa l sources. For most cases, i o n i c s t r e n g t h i s about

0.1 and T i s 20 t o 25OC. itr rate da ta p r i m a r i l y f r om Lerman and C h i l d s

(1973), CMOS and CMT da ta supp l i ed ,by manufacturers. React ions f o r p ro tons

a re H3Y+H,0 = H,Y+H,o+, pK,, e tc . React ions w i t h meta ls a re

+ Y 3 - = M ~ Y ~ - ~ , ~ K M .

METAL

H+, pK1

PK2

PK3 M~~~

ca2+

~ n "

~ e "

cd2+

cu2+

pb2+

zn2+

H~~~

**These da ta a re f o r 100% a c t i v e carboxymethyltartronate. CMT i s about 76%

a c t i v e by weight.

CMOS

2.5

3.8

5.0

2.7

3.9

3.1 - -

5.0

6.4

5.5 -

5.5 -

C I TRATE

3.1

4.8

6.4

3.4

3.6

3.7

3.1

5.0

5.4

5.9

6.5

5.0 .

10.9

11.4

CMT **

1.7

3.3

4.4

2.8

4.6

3.8

3.7

3.9

3.8

5.2

6.0

- 4.9 - -

The e q u i l i b r i u m composit ion o f a s o l u t i o n c o n s i s t i n g o f a m i x t u r e o f

meta ls (e.g., C a ( I I ) , M g ( I I ) , C u ( I I ) , P b ( I I ) , H(1) ) and l i gands (e.g.,

c i t r a t e , humic substances, C03-2, OH-) i s es tab l i shed by compe t i t i on among

many reac t i ons i n c l u d i n g pro ton t rans fe r , complex format ion, p r e c i p i t a t i o n ,

redox, and adsorp t ion e q u i l i b r i a . The mathematical complex i ty o f t h e

r e s u l t i n g c a l c u l a t i o n s has been reso lved by t h e use of computers t o so l ve t h e

e q u i l i b r i u m equat ions involved. The chemical complex i t ies o f - t h e problem can

i nc lude a l ack o f r e l i a b l e thermodynamic da ta f o r t h e r e a c t i o n s i nvo l ved and

t h e ex ten t t o which r e a c t i o n k i n e t i c s negate an e q u i l i b r i u m approach.

A good example o f t h e a p p l i c a t i o n o f thermodynamics and k i n e t i c s t o

p r e d i c t t h e e f f e c t o f organic detergent b u i l d e r s i s prov ided by Lerman and .

Ch i l ds (1973). For c i t r a t e , these authors p r e d i c t t h a t t h e complexes o f

c i t r a t e w i t h F e ( I I 1 ) and C u ( I I 1 ) w i 11 predominate i n waters w i t h a major i o n

composit ion s i m i l a r t o t he Great Lakes and a pH o f 8. Corr~plexes o f c i t r a t e

w i t h P b ( I I ) , N i ( I I ) , and Zn( I1 ) may a l so be formed. Since t h e thermodynamic

da ta f o r CMOS and CMT are s i m i l a r t o those f o r c i t r a t e (Tab le I ) , t h e r e s u l t s

of t h e analyses by Lerman and Ch i l ds f o r c i t r a t e may be app l i ed q u a l i t a t i v e l y

t o CMOS and CMT. A

TRACE.METAL-CHELATOR INTERACTIONS AND EFFECTS

An important e f f e c t o f organic detergent b u i l d e r s on t h e environment may

be expected t o r e s u l t f rom t h e i n t e r a c t i o n s o f these che la to rs w i t h t r a c e

metals, and t h e subsequent e f f e c t s o f changes i n metal spec ia t i on on

phytoplankton growth (see sec t i on on Eu t roph i ca t i on ) . I n t h i s summary, t h e

poss.ible e f f e c t s o f organic che la to rs are examined i n two simp1 i f i e d (model)

systems, and poss ib le b i o l o g i c a l e f f e c t s are suggested.

CASE I: Consider a l a k e i n t o which a metal o f i n t e r e s t has been con t i nuous l y

introduced. Assume t h a t none o f t h i s metal i s deposi ted i n t h e sediments,

t h a t , t h e l ake can be descr ibed as a complete ly mixed box o r r e a c t o r and.- that

t h e system has reached a steady s ta te . L e t t h e t o t a l metal concen t ra t i on

i n t h e i n f l o w t o t h e l a k e be [Me?] i t h e t o t a l meta l concen t ra t i on i n t h e :'.

out f low be [ M ~ T ] ,, and t h e t o t a l metal concen t ra t i on i n t h e l a k e be -[MeT]1l*:.:

Since t h e l a k e i s corrlpletely mixed, [ M ~ T ] = [ M ~ T ] 1. Since no metal i s removed

by deposi t ion, [ M ~ T ] i' [M~T],; assume t h a t these are 1 0 - 6 ~ , a concent ra t ion

app l i cab le t o t he Great Lakes. A t o t a l metal concent ra t ion i s comprised o f

t he sum o f t he concentrat ions o f t h e so lub le species, such as [ M ~ T ] = [MeZ] + [M~OHZ-'1 + [ ~ e C 0 3 ~ - ~ ] + e tc . Here z i s t he charge o f t h e f r e e metal species

(e.g., f o r , Cu2+, z = 2) .

Next, add an -organic che la to r t o the system, a l s o a t t o t a l concent ra t ion

[CHELT] of 1 0 - 6 ~ . Here, [CHELT] = [CHEL-Y] + [HCHELI-Y + [H~CHEL*-Y +

[MeCHELZ-Y] + etc . The symbol y i s the charge o f the uncomplexed l i g a n d

(e.g. f o r c i t r a t e , y = 3 ) . Suppose t h a t t h i s che ' la tor forms s t rong complexes

w i t h the metal, so t h a t [CHELT] "= [MeCHELz-Y] -7 [MeTl0 = 1 o e 6 ~ . The t o t a l concent ra t ion o f metal i n t h e lake w i l l remain unchanged a t - ' '

1 0 - 6 ~ . However, t h e .concentrat ion o f f r e e metal wi31 -be reduced

subs$ant ia l ly, by severa l orders o f magnitude. The concent ra t ion o f f r e e

chel a t o r [CHEL-Y] w i 1 1 a1 so be smal l .

These changes can have b i o l o g i c a l e f f e c t s . For example, Sunda and

Gui.1 l a r d ( 1976) and Anderson and Morel (1978) have demonstrated t h a t t h e

a c t i v i t y o f f r e e cup r i c ion un ique ly determines the copper t o x i c i t y f o r

severa l a l g a l species. S im i l a r r e s u l t s have been c a l c u l a t e d by Jackson and

Morgan (1978). These r e s u l t s i n d i c a t e t h a t t he format ion o f meta l -che la te

complexes can s t imu la te phytoplankton a c t i v i t y t h a t has otherwise been

repressed by t o x i c metal i on a c t i v i t y , and can a l so lead t o s h i f t s i n a l g a l

spec ia t ion f rom t o l e r a n t t o s e n s i t i v e species; For t he example discussed

here, i n which the a d d i t i o n o f the organic che la to r does n o t a f f e c t [ M ~ T ] 1,

the t o t a l concent ra t ion i n the lake b u t s u b s t a n t i a l l y reduces [MeZ] , e f f e c t s

such as these are p laus ib le .

The b i o d e g r a d a b i l i t y o f the che la to r i s an important f a c t o r i n t h i s

analys is . I f t h e organic detergent b u i l d e r i s biodegradable, then the e f f e c t s

o f the che la to r on metal i o n spec ia t ion and on phytoplankton w i l l d isappear as

i t i s degraded. Rap id ly degradable b u i l d e r s w i l l produce n e g l i g i b l e e f f e c t s .

An important associated quest ion i s the e f f e c t o f meta ls on the

b i o d e g r a d a b i l i t y o f t he organic bu i l de r . Many experiments g i ve c o n f l i c t i n g

r e s u l t s . One f a c t o r t h a t may a f f e c t t h e b iodegradab i l i t y o f a meta l -o rgan ic

complex i s i t s r a t e o f d i s s o c i a t i o n . The f o l l o w i n g example i s taken ' f rom

Jackson and Morgan (1978). Consider t h e Fe(II1)-EDTA i n t e r a c t i o n a t pH 8.

The e f f e c t i v e e q u i l i b r i u m cons tan t (K) f o r t h i s r e a c t i o n i s about 10". If

t h e a s s o c i a t i o n r e a c t i o n i s r ap id , so t h a t kl i s i n t h e o rder o f l ~ ~ ~ o l e s / s ,

then t h e d i s s o c i a t i o n r a t e constant , kz , i s k1/K=(106/101'+) o r about 10'8s'1.

Th is i n d i c a t e s a ha l f t ime f o r t h e d i s s o c i a t i o n r e a c t i o n o f about 2 years. I n

t h i s ana lys is , t h e d i s s o c i a t i o n i s r e l a t e d t o t h e e q u i l i b r i u m cons tan t f o r t h e

f o rma t i on o f t h e complex. Large e q u i l i b r i u m cons tan ts suggest s low

d i s s o c i a t i o n ra tes .

Th is s imp le ana l ys i s i n d i c a t e s t h a t s t r o n g meta l c h e l a t o r s such as EDTA

can fo rm meta l complexes t h a t d i s s o c i a t e s l o w l y . I f unqomplexed EDTA ( i .e., ; EDTA t h a t has no t formed r i n g s t r u c t u r e s w i t h meta l i o n s ) i s b iodegrddable

w h i l e metal-EDTA c h e l a t e complexes a re no1 degradable, t hen t h e k i n e t i c s o f

b iodegrada t ion may be r e l a t e d t o t h e k i n e t i c s o f d i s s o c i a t i o n o f t h e

m e t a l - l i g a n d complex.

Th is ana l ys i s suggests t h a t c i t r a t e , CMOS, and CMT s h o l l d be b iodegradable

f o r a l l meta l -o rgan ic i n t e r a c t i o n s presented i n Table 1 w i t h t h e p o s s i b l e

excep t ion o f H g ( I 1 ) - c i t r a t e and F e ( I I 1 ) C i t r a t e , s i n c e K / k l i s a second o r

l e s s f o r kl = l o 6 Moles/s. Other c a l c u l a t i o n s i n d i c a t e t h a t such a

H g - c i t r a t e complex w i l l e x i s t o n l y i n ve ry low concen t ra t i ons s i nce Hg w i l l

f o rm hydroxomercur i c complexes a t n e u t r a l pH.

CASE 11: Consider a l a k e s i m i l a r t o t h a t i n Case 1, save t h a t t h e metal o f

i n t e r e s t i s removed i n s u b s t a n t i a l q u a n t i t i e s by d e p o s i t i o n i n t h e sediments.

L e t [ M ~ T ] i = 10-6M as before. I f i t i s assumed t h a t 90 pe rcen t o f t h e meta l '

i s r e t a i n e d i n t h e l a k e sediments, t hen a t a s teady s ta te , [MET] ' = [METIo=

10-7M. Many p o s s i b l e pathways e x i s t f o r i n c o r p o r a t i n g Me i n t o a s o l i d

phase and d e p o s i t i n g i t i n t h e sediments; assume t h a t a p r e c i p i t a t e , MeA(S),

i s formed.

The f o l l o w i ~ g r e a c t i o n f o r t h e s o l i d can be w r i t t e n :

I f the concent ra t i o n of t h e an ion [A-Y] >> [ M ~ T ] ,

Th is would descr ibe, f o r example, t h e Cd2+ concen t ra t i on i n a water

con ta in i ng s u f f i c i e n t C0;2to p r e c i p i t a t e CdCOa(s) and i n which [ c 0 i 2 ] >>

[cd2+]. Under these c o n d i t i o n s t h e a c t i v i t y o f t h e f r e e metal i o n i s

c o n t r o l l e d by t h e presence o f t h e s o l i d phase.

Next, add an o rgan ic c h e l a t o r i n t o t h e system, i n t h i s case a t [CHELT] =

IO'~M. Consider t h a t t h i s c h e l a t o r forms s t rong complexes w i t h t h e meta l .

A t equ i l i b r i um, (1) t h e t o t a l concen t ra t i on o f metal , [MET] w i l l double

t o 2 x 10'7M, as some o f t he Me A (s ) d isso lves , ( 2 ) t h e d e p o s i t i o n o f Me

i n t h e l a k e w i 11 be reduced f rom 90 percen t t o 80 percent , ( 3 ) t h e a c t i v i t y of

t he f r e e metal , [MEZ] , w i l l remain unchanged, and (4 ) t h e che l a t o r w i 11 be

complexed w i t h t h e meta l so t h a t [CHELT~ - [MeCHELz-Y]. Under these

circumstances, t h e o rgan ic c h e l a t o r would have no e f f e c t s on phy top lank ton

growth r a t e s o r s p e c i a t i o n by mechanisms assoc ia ted w i t h t h e metals.

These e f f e c t s are a l s o r e l a t e d t o t h e b i o d e g r a d a b i l i t y o f t h e c h e l a t o r

and, as before, may be a f f e c t e d by t h e k i n e t i c s o f d i s s o c i a t i o n o f t h e

ME-CHEL~'Y compl ex.

SUMMARY

The f o l l o w i n g p o i n t s are emphasized:

1. The aquat ic chemist ry o f organic detergent b u i l d e r s i s dominated by

t h e i r a b i l i t y t o form meta l -che la te complexes.

. 2. I t i s a reasonable ex t rapo l a t i o n o f avai 1 ab le evidence t o . . cons ide r

t h a t organic che la to rs can c o n t r o l t he a c t i v i t y o f t o x i c f r e e metal

i ons i n some n a t u r a l waters, and hence a f f e c t phytoplankton growth

r a t e s and speci a t i on.

3. B i o d e g r a d a b i l i t y may be r e l a t e d t o t h e k i n e t i c s o f d i s s o c i a t i o n o f

meta l -chel a te complexes. Th i s i s suggest ive and p r e l iminary.

4. E f f e c t s o f organic b u i l d e r s on the aquat ic environment can be

expected t o be s i t e - s p e c i f i c , and r e l a t e d t o such f a c t o r s as t h e t ype

and ex ten t o f metal depos i t i on t h a t occurs p r i o r t o a d d i t i o n o f t h e

che la to r . For example, meta l depos i t i on i s expected t o reduce t h e

i n f l u e n c e o f a che la to r by b u f f e r i n g s o l u b l e f r e e metal

concentrat ions.

5. Major problems o f these types are no t a n t i c i p a t e d f o r c i t r a t e , CMOS,

and carboxymethyl t a r t r o n a t e , because of t h e r e 1 a t i v e l y weak

meta l -b inding a f f i n i t y o f these substances. Some quest ions a r i s e

w i t h d i t a r t r o n a t e , a minor component o f CMT, b u t i n f o r m a t i o n i s no t

a v a i l ab le t o assess them.

REFERENCES

Anderson, D.M., and F.M.M. Morel, 1978. Copper s e n s i t i v i t y of Gonyaul ax

tamarensis, Limnology and Oceanography, - 23:283-295.

Jackson, G.A. and J.J. Morgan, 1978. Trace meta l -che la to r i n t e r a c t i o n s and

phytoplankton growth i n seawater media: Theo re t i ca l ana l ys i s and comparison

w i t h repo r ted observat ion, Limnology and Oceanography, - 23:268-282.

Lerman A., and C.W. Chi1 ds, 1973. Metal-Organic complexes i n n a t u r a l waters:

Cont ro l o f d i s t r i b u t i o n by thermodynamic, k i n e t i c , and phys ica l f ac to rs , i n

Trace Meta ls and Metal-Organic I n t e r a c t i o n s i n Natura l Waters, e d i t e d by P.C.

Singer, Ann Arbor Science, 201-235.

Sunda, W.G. and R.R. Gui 1 la rd , 1976. Re1 a t i onsh ip between c u p r i c i o n a c t i v i t y

and t h e t o x i c i t y of copper t o phytoplankton, Journal o f Marine Research,

34:511-529. -

- - . MICROBIOLOGY AND BIOCHEMISTRY OF DEGRADATION -

The chemist ry o f t h e th ree organic compounds and t h e i m p u r i t i e s present i n

b u i l d e r s w i t h them has been-discussed i n t h e prev ious sect ion. O f note i s t h e

f a c t t h a t CMOS and CMT and i t s at tendant impur i t i es , d i g l y c o l a t e and

d i t a r t r o n a t e , do no t occur n a t u r a l l y . A l l are a l i p h a t i c ethers. C i t r a t e , on

t h e o ther hand, con ta ins no e ther l i nkage and i t s s ta tus as a nat.ural product

i s w e l l establ ished.

MICROBIOLOGY OF DEGRADING ORGANISMS

To attempt t o l i s t a l l microorganisms capable o f u t i l i z i n g c i t r a t e f o r . growth, o r ab le t o o x i d i z e c i t r a t e , would be a major task because c i t r a t e i s

such a c e n t r a l me tabo l i t e i n metabo l i c processes. The bas i s f o r t h i s

widespread d i s t r i b u t i o n - i s t h e occurrence o f t h e c i t r i c ac id o r t r i c a r b o x y l i c

a c i d c y c l e e i t h e r i n an i n t a c t form o r i n i t s var ious m o d i f i c a t i o n s :in most

aerobic organisms. Furthermore a number o f b i o l o g i c a l systems such as c i t r u s , .

f r u i t s are producers o f c i t r i c acid. C i t r a t e , there fo re , i s a n a t u r a l p roduc t

f o r which the re are a l a rge number o f m i c r o b i a l agents a v a i l a b l e f o r i t s

degradation. The controversy many years ago as t o whether b a c t e r i a d i d i n

f a c t possess t h e t r i c a r b o x y l i c ac id (TCA) c y c l e was reso lved when i t was

demonstrated t h a t a number o f organisms possessed f u n c t i o n i n g TCA c y c l e

enzymes b u t lacked t h e a b i l i t y t o o x i d i z e c i t r a t e when i t was prov ided

exogenously because they possessed no t r a n s p o r t mechanism f o r c i t r a t e uptake

(Swim and Krampitz, 1954). Even though some organisms are impermeable t o

c i t r a t e a v a r i e t y o f species have been shown t o e labora te c i t r a t e - s p e c i f i c

t r a n s p o r t mechanisms. O f note t o o i s t h e f i n d i n g t h a t c i t r a t e readiiy

supports anaerobic growth as w e l l as growth o f aerobic organisms (Cody and

Tisher, 1963; Brewer and Werkman,. 1939; Dagley, 1954; Dagley and Dawes, 1953;

O'Br ien and Stern, 1969) showing t h a t t he a v a i l a b i l i t y o f d isso lved oxygen

need no t be a f a c t o r l i m i t i n g c i t r a t e degradation.

Degradation o f CMOS by a pure c u l t u r e o f what i s apparent ly a species of

Zooglea, an aerobic organism frequently found in the flocs of treatment

plants, has been described (Peterson and Llaneza, 1974). This organism was

isolated from semi-continuous acti,vated sludge units degrading CMOS, a process

which required 3-5 days for acclimation (Lever, 1977). Other microorganisms

such as species of Pseudomonas that grow in pure culture at the expense of

CMOS have a1 so been isolated by research workers at Lever and by Dr. Cain,

University of Canterbury, England (in a research program supported by Lever;

Weaver, personal communication, about Cai n's progress .reports). Recent work

in-Cain's laboratory has also led to the isolation of CMOS-degrading bacteria

from saline environments. The organisms isolated include yeasts, gram-

positive cocci and gram-negative rods. Certain of these are also capable of

growth with compounds structurally re1 ated to CMOS such as methyl -substituted -

and carboxymethyl substituted derivatives (where the substitution is on the

methylene adjacent to the ether oxygen). These results give no indication

that is01 ation of such organisms was a difficult problem suggesting,

therefore, that'they are isolated readily." When a variety of bacteria able to

grow 'with a given organic compound can be readily isolated it is (general ly a

re1 iable indication that the compound in question is readily biodegradable.

While-there are no reports of isolation of pure cultures of anaerobic organisms - uti'l iiing CMOS; ttie .prompt degradat'ion 'of this 'materi a1 i.n anaer'obic

digestors (Viccaro and Ambye, 1977) suggests either that such organisms may be

isolated readily or that suitable microbial communities are established

readily.

The impurities in CMOS-maleic, fumaric and glycolic acids-are all

compounds that support the growth of numerous microorganisms in soil and

water. For example numerous strains from the genus Pseudomonas possess the

ability to grow with these compounds as sole sources of carbon (Stanier -- et al.

1966).

By contrast, organisms isolated for ability to grow with CMT as sole

carbon source were obtained less readily from continuous-feed activated sludge

units, which required up to eight weeks before acclimation (Monsanto, 1978).

Their isolation was accomplished when it was realized that the organisms

responsible for CMT degradation were fastidious and possessed a requirement

f o r - d-b io t i n . P rov i s i on o f t h i s co- fac to r al lowed i s o l a t i o n o f organisms

i d e n t i f i e d as species o f Mycobacterium ( G l e d h i l l , personal communication).

Organisms able t o u t i l i z e e i t h e r d i g l y c o l a t e o r d i t a r t r o n a t e appear t o have

been i s o l a t e d bu t no t charac ter ized f u r t h e r ( G l e d h i l l , personal communication).

The rou tes by which c i t r a t e , CMOS, and CMT are degraded are based on

s tud ies w i t h pure c u l t u r e s o f organisms which degrade these compounds. Since

t h e pathway descr ibed f o r CMT i s t h a t found i n i s o l a t e s f rom o n l y one genus i t

may no t be t h e o n l y degradat ive , r o u t e a v a l l a b l e f o r m i c r o b i a l d i s s i m i l a t i o n o f

t h i s ma te r i a l . On t h e o ther hand s tud ies w i t h d i f f e r e n t c i t r a t e - and

CMOS-degrading organisms have been conducted and suggest t h a t t h e pathways

e luc ida ted are those which serve gene ra l l y i n t he m i c r o b i a l d i s s i m i l a t i o n .. o f .

these compounds.

BIOCHEMISTRY OF DEGRADATION

. .

i ) LIPTAKE BY MICROORGANISMS . .

The t ranspo r t o f low molecular weight cornpounds across the membrane o f

b a c t e r i a l c e l l s f r e q u e n t l y i nvo l ves s p e c i f i c t r a n s p o r t mechanisms which can

concentrate these m a t e r i a l s aga ins t a p r e v a i l i n g concent ra t ion gradient . For

c i t r a t e uptake i t i s known t h a t c e r t a i n organisms such as B a c i l l u s s u b t i l i s

(Wi 1 1 ecke and Pardee, 1971), Azotobacter v i ne l andi i (Postma and Van Dam,

1971), Aerobacter (Enterobacter) c loacae and Aerobacter (Enterobacter)

aerogenes synthesize s p e c i f i c c i t r a t e - t r a n s p o r t components o n l y when c i t r a t e

i s present (Ar ima -- e t a l . 1972; V i l l a r r e a l and Ruiz-Herrera, 1969). Those

organisms unable t o e labora te these t r a n s p o r t systems are, as a consequence,

unab1.e t o degrade c i t r a t e . The number and v a r i e t y o f organisms which can

produce these systems, however, as evidenced by t h e i r a b i l i t y t o grow w i t h

c i t r a t e as so le carbon source, i s g rea t and would p lace no l i m i t a t i o n on

c i t r a t e d i ss im i 1 a t i o n i n v i r t u a l l y any environment where m i c r o b i a l 1 i f e can

e x i s t . The uptake o f compounds such as CMOS and CMT by b a c t e r i a i s l i k e l y t o

i n v o l v e s i m i l a r types o f t r a n s l o c a t i o n mechanisms. I n view o f t h e i r

s t r ,uctura l s i rn i l a r i t i e s t o c i t r a t e t hey ni ight even "borrow" t h e c i t r a t e

t r a n s p o r t mechanism i f they are capable -of e l i c i t i n g t h e syn thes is o f t h e

necessary membrane pro te ins . A recent communication f rom Ca in 's l a b o r a t o r y

(Cain and King, 1979) suggests t h a t uptake o f a range o f de tergent -bu i lders

may occur v i a t h e c i t r a t e - t r a n s p o r t system. I n fo rma t i on on t h i s p o i n t i s

meagre and must await t h e r e p o r t o f a d d i t i o n a l experimental work.

: , * . . . . . . . . As mentidned &rfi e? c i t r a t e me t i bo l ism i s r & d i li accompl ished 'by

.. f . . . . - , . . . . . . . . . . . .

microorganisms wh ich~~possess ,. . t he enzymes o f t h e ' t r i c i r b ~ x ~ l ' i c a c i d cycle;. . . . - ,

s ince many a e i b b i c organisms t h i s s y s t e m t h e o n l y f ac to r which bight o t h e i w i i e l s i m i t i i t r a t e . degradat ion i s t he read iness w i t h which c i t r a t e - c & '

. . . . ; ; . .

ente; sukh c e l ' l s ' a n d redch the 'enzymes o f t h i s systeim. T h e p r e v i o " i s e c t i o n

r e f e r r e d t o mechanisms f o r c i t r a t e uptake. Desc r i p t i on o f t he events o f t h e

t r i c a r b o x y l i c a c i d c y c l e w i l l no t be attempted here s ince t h i s r e a c t i o n

sequence can be found i n most modern b i o l o g y tex t s . It i s s u f f i c i e n t t o s t a t e

t h a t i n one t u r n of t h i s cyc le c i t r a t e can be ox id i zed t o another i n te rmed ia ry

metabol i te , oxaloacetate, v i a a sequence i n v o l v i n g ha l f a dozen o r so

in termediates. Under some circumstances t h i s pathway may be modi f ied. I n t h e

presence of acetate, o r o f compounds which are degraded l a r g e l y t o acetate,

microorganisms can a1 so form a n c i l 1 ary enzymes which c o n s t i t u t e a

supplementary sequence c a l l e d the ' g l yoxy l a te by-pass' (Kornberg and Krebs,

1957). Th i s sequence i n no way d imin ishes t h e capac i t y of c e l l s t o

d i s s i m i 1 a t e c i t r a t e . Other microorganisms are known t o have an incomplete

t r i c a r b o x y l i c ac id cycle; such organisms, which i nc lude a v a r i e t y o f

chemol i tho t roph ic and p h o t o l i t h o t r o p h i c b a c t e r i a and blue-green algae, are no t

g e n e r a l l y impor tant agents i n t h e degradat ion of organic compounds.

CMOS degradat ion has been s tud ied i n a species o f Zooglea a t t he enzymic

l e v e l by ~ e t e r s o n and ~ l a n e G (1974) and a1 so by c i i n and' h i s assoc ia tes w i t h

o ther organisms ( p e r s o n a l l y communicated by D r . Weaver). The r e s u l t s of bo th

groups i n d i c a t e t h a t CMOS i s cleaved by a - 8-el iminase-type enzyme t o g i v e

g l y c o l i c and fumar ic acids. The t r a n s na ture of t h e l a t t e r product i s a

f u r t h e r i n d i c a t i o n t h a t t he reac t i on ,ca ta l yzed may i n f a c t be a t r a n s

8-e I iminat ion.

COOH COOH

HOCH

I

COOH

CMOS

I COOH

Fumaric ac id

. . .

G l y c o l i c ac id

The c loses t known analogies t o reac t i ons of t h i s type are cata lyzed by

b a c t e r i a l eliminase-enzymes which ac t on uron ic a c i d polymers such as

hya luron ic and p e c t i c acids t o g i ve aB-unsaturated carboxyl i c ac ids . . .

(Ludeweig -- e t a l . 1961; S t a r r and Moran, 1962). Other reac t i ons having s i m i l a r

mechanisms are those which ca ta lyze the t rans e l i m i n a t i o n o f water, r a t h e r

than of organic hydroxy compounds, as f o r example t h e dehydrat ion o f L-mal ic

a c i d t o fumaric acid. O f specia l note i s the f a c t t h a t cleavage o f t he

a l i p h a t i c e ther bond i s accomplished w i thou t a requirement f o r oxygen ( a

requirement which i s known t o apply i n an a1 t e r n a t i v e e ther -c leav ing mechanism

found i n b a c t e r i a a c t i n g on a l k y l e thers o f phenols). Such an e l im inase

r e a c t i o n there fore can f u n c t i o n equa l l y we1 1 a e r o b i c a l l y o r anaerobical ly.

This cont ras ts w i t h t h e aerobic degradat ion o f NTA by b a c t e r i a where oxygen i s

requ i red as cosubstrate i n e a r l y reac t i ons (F i res tone and Tiedje, 1978). The

products o f t h e r e a c t i o n (which a lso happen t o be t h e impur i t i es , fumaric and

g l y c o l i c ac ids) are both na tu ra l products and r e a d i l y metabol i z a b l e compounds

known t o support t h e growth o f d i f f e r e n t microorganisms.

D e t a i l s o f t he reac t i ons employed by the Mycobacterium species t o degrade

CMT are no t y e t f u l l y e luc idated. P re l im ina ry i n fo rma t ion suggests t h a t

malonic a c i d i s one r e a c t i o n product w i t h g l y c o l i c a c i d suspected as the o ther

fragment ( G l e d h i l l , 1976). If these are i n f a c t t h e irrmediate products o f CMT

at tack, then a novel reduc t i ve r e a c t i o n f o r e ther cleavage occurs i n t he

organism s tud ied and warrants f u r t h e r s tudy f rom both a chemical and a

biochemical standpoint. Th is i s so because the apparent r e a c t i o n cannot be

described as a 0 -e l im ina t ion , does no t q u a l i f y as a r e a c t i o n i n i t i a t e d by

oxygen i nco rpo ra t i on and i s not a simple hydro lys is . Any f u r t h e r specu la t ion

about t h e p rec i se mechanisms i nvo l ved must awai t a more complete d e s c r i p t i o n

o f t h e enzyme-catalyzed r e a c t i o n which i n i t i a t e s a t t ack on CMT.

No i n fo rma t i on i s a v a i l a b l e t o show how the s i g n i f i c a n t i m p u r i t i e s present

i n CMT, d i g l y c o l a te and d i t a r t r o n a t e , undergo degradat ion s ince t h e r e do n o t

appear t o b e any r e p o r t s desc r i b ing microorganisms, capable o f growth a t t h e

expense o f these compounds.

Apart f rom the p u r i f i c a t i o n o f t he enzymes, aconitase, c i t r a t e lyase, and

i s o c i t r a t e l yase f rom d i f f e r e n t b a c t e r i a f o r s tud ies o f t h e i r biochemical

p roper t ies , t h e r e are no repor ted p u r i f i c a t i o n s o f enzymes which a c t on t h e

o ther n i t r ogen - f ree organic bu i lders .

i i i ) STRUCTURALLY RELATED COMPOUNDS AND THEIR REACTIONS

The re levance o f t h i s area o f d iscuss ion t o t h e present and f u t u r e

p o t e n t i a l o f b a c t e r i a t o evolve new degradat ive a b i l i t i e s was discussed i n t h e

corresponding chapter on Biochemist ry and Mic rob io logy o f NTA Degradat ion ( I JC

F i n a l Report on NTA, 1978). The r e a c t ions which c i t r a t e undergoes i n

b i o l o g i c a l systems are a1 1 examples o f c lasses o f biochemical r e a c t i o n s

encountered w i t h s t r u c t u r a l l y re1 ated compounds. Thus the dehydrat ion and

rehyd ra t i on e f f e c t e d by aconitase, and t h e a ldo lase type cleavages brought

about by i s o c i t r a t e l yase and c i t r a t e l yase have t h e i r enzymic counterpar ts

a c t i n g on s t r u c t u r a l l y s i m i l a r b i o l o g i c a l metabol i tes. Simi 1 a r l y t h e enzyme,

i s o c i t r a t e dehydrogenase, ca ta lyzes a r e a c t i o n o f o x i d a t i v e decarboxy la t ion o f

a type known t o occur i n o ther systems.

CMOS and CMT - b o t h possess a s t r u c t u r a l feature, t h e oxygen-containing

e ther 1 inkage, which requ i res biochemical cleavage be fore ex tens ive

de,gradation can occur. W h i l e a number. o f s imi 1 ar 0 -d i a1 k y l e thers are

recognized as n a t u r a l products l i t t l e i s known o f t h e b i o l o g i c a l mechanism o f

ether-bond cleavage f o r t h i s c l ass o f compounds. I n t e r e s t i n t h e b i o l o g i c a l

r eac t i ons o f t h i s f u n c t i o n a l - group der ives .a1 so f rom t h e f a c t t h a t i t i s . found

i n t he po lye thy lene g l y c o l s and other s y n t h e t i c ethers. I t i s i n f a c t

accurate t o s t a t e t h a t o f t he var ious d i a l k y l e thers s tud ied the work o n CMOS

provides one o f t he more complete p i c t u r e s o f how these compounds are

degraded. It should no t be fo rgo t ten , however, t h a t CMOS does possess i t s

e ther f u n c t i o n on a carbon i n a p o s i t i o n B- t o one o f i t s carboxyl groups

and t h i s places t h i s compound i n a r a t h e r spec ia l category o f a l i p h a t i c e thers

w i t h c lose counterpar ts found among the uron ic ac id polymers.

CMT has i t s ether f u n c t i o n i n a p o s i t i o n a- t o e i t h e r carboxyl and has .

t he re fo re t o be considered as a member of a somewhat d i f f e ren t c lass o f ether.s

from that' which inc ludes -CMOS, w i t h p r e d i c t a b l y d i f f e r e n t chemical suscept-

i b i l i t y o r r e a c t i v i t y . As mentioned above a v a i l a b l e evidence suggests - tha t .a

novel r e a c t i o n may be invo lved bu t lack o f in fo rmat ion about t he biochem,ical- .

r e a c t i o n accomplishing i t s cleavage l i m i t s d iscuss ion o f r e l a t e d systems and

react ions.

Wi th the except ion of c i t r a t e the re are no r e p o r t s o f s tud ies o f the

anaerobic degradat ion o f organic b u i l d e r s which revea l whether t h e i r degra;

da t i on i s accomplished by reac t i ons d i f f e ren t f rom those o u t l i n e d above. For

CMT t h i s would appear t o be a d i f f i c u l t problem t o address s ince i t s degra-

da t i on d i d no t take p lace i n anaerobic d iges tors (Monsanto, 1978). CMOS, on

the other hand, was completely degraded i n anaerobic d iges ters a f te r a l a g o f

about one week as assessed by disappearance o f 14C- l a b e l l e d CMOS and by

i t s conversion t o 14C02 and 14CH4 (V iccaro and Ambye, 1977). While no

i n fo rma t ion i s a v a i l a b l e t o show the biochemical reac t i ons involved, i t was

shown e a r l i e r i n t h i s account t h a t t he cleavage r e a c t i o n f o r CMOS i n aerobic

organisms had no oxygen requirement and could, there fore , p rov ide a r o u t e by

which CMOS i s degraded w i t h equal f a c i l i t y under aerobic and anaerobic

conditons. I n t e r e s t i n g l y one o f t h e products, fumarate, can serve as an

e l e c t r o n acceptor i n anaerobic r e s p i r a t i o n and can i t s e l f be degraded by the

same general process i f a l t e r n a t i v e e l e c t r o n acceptors are ava i lab le .

G lyco la te can undergo many reac t i ons i n b i o l o g i c a l systems f o r which oxygen i s

n o t an o b l i g a t o r y cosubstrate. It can, f o r example, be converted t o py ruv i c

acid, by reac t i ons which f u n c t i o n as r e a d i l y anaerob ica l l y as a e r o b i c a l l y

(Kornberg and Gotto, 1961).

The most complete ly descr ibed mechanism f o r c i t r a t e degradation, under

anaerobic cond i t ions , i s t h a t found i n e n t e r i c b a c t e r i a such as Enterobacter

aerogenes, Escher ich ia c o l i and r e l a t e d organisms which degrade c i t r a t e as a

fermentable subs t ra te i n t he absence of exogenous e l e c t r o n acceptors (Dagley,

1954). The same mechanism i s invo lved i n c i t r a t e u t i l i z a t i o n by t h e

photosynthe t ic bacterium, Rhodopseudomonas g e l a t i nosa (Beuscher -- e t a1 . 1974).

An enzyme i s induced i n a s p e c i f i c f ash ion by anaerobic growth w i t h c i t r a t e

which cata lyzes t h e cleavage o f c i t r a t e t o oxa lace ta te and acetate; these

simple compounds can be degraded f u r t h e r by anaerobic processes. I n t h e

presence o f ex te rna l e l e c t r o n acceptors such as n i t r a t e o r fumarate many

organisms can -swi tch t h e i r fe rmenta t i ve metabolism ,over t o anaerobic

r e s p i r a t i o n . and accompl i s h cons iderab ly more m-ineral i z a t i o n as a r e s u l t .

i ) C i t r a t e i s r e a d i l y biodegradable under most cond i t i ons where m i c r o b i a l

l i f e can e x i s t p r i n c i p a l l y because i t i s a n a t u r a l product and a c e n t r a l

in te rmed iary me tabo l i t e i n most b i o l o g i c a l systems. A wide v a r i e t y o f

bac ter ia , both aerobic and anaerobic, are known which possess t h e necessary

systems f o r c i t r a t e uptake and metabol ism.

i i ) CMOS i s somewhat, less r e a d i l y biodegraded than i s c i t r a t e as i n d i c a t e d

by the longer t imes r e q u i r e d be fore i t s disappearance can be shown.

Nonetheless a v a r i e t y of b a c t e r i a l s t r a i n s have been i s o l a t e d which can

u t i l i z e i t as so le carbon source. I t s degradat ion t o simple biochemical

fragments i s .brought about by a s i n g l e enzyme system which does no t r e q u i r e

molecular oxygen. Consequently t h i s aspect o f i t s b iodegradat ion p laces no

c o n s t r a i n t upon t h e a b i l i t y o f b a c t e r i a t o d i s s i m i l a t e t h e compound under

anaerobic .as w e l l as aerobic condi t ions.

i i i ) Of t h e t h r e e b u i l d e r s CMT appears t o be t h e l e a s t biodegradable.

Extended per iods o f time, up t o e i g h t weeks, are requ i red be fore m i c r o b i a l

communities are es tab l i shed t o e f f e c t i t s degradation. From such communities

o n l y one type o f b a c t e r i a l i s o l a t e , i d e n t i f i e d as a species o f Mycobacterium,

cou ld be i so la ted . These organisms are c h a r a c t e r i s t i c a l l y s l ow-growing and

t h e s t r a i n s s tud ied here a l so r e q u i r e d a co fac to r i n order t o grow.

Consequently degradat ion o f CMT may depend on a l i m i t e d and f a s t i d i o u s

m i c r o f l o r a . Anaerobic degradat ion o f CMT has no t been observed. D e t a i l s o f

t h e enzymology of i t s degradat ion a re no t y?t a v a i l a b l e and t h e r e f o r e do n o t

pe rm i t specu la t ion about t h e func t i on ing o f such a system under anaerobic

cond i t ions .

REFERENCES

Arima, K., K. Watanabe and T. Beppu, 1972. C i t r a t e t ranspor t -enhancing f 'ac to rs

i n bac te r i a . I . I s01 a t i o n of t h e c i t r a t e t ranspor t -enhancing f a c t o r s f rom

Aerobacter cloacae. Ag r i c. B i o l . Chem. - 36:2105-2112.

Beuscher, N., F. Mayer and G. Gottschalk, 1974. C i t r a t e l yase f rom Rhodop-

seudomonas ge! a t inosa: p u r i f i c a t i o n , e l e c t r o n microscopy and subun i t

s t ruc tu re . Arch. M i k r o b i o l . 100:307-328.

Brewer, C.R. and C.H. Werkman, 1939. The anerobic d i s s i , m i l a t i o n o f c i t r i c

ac id by Aerobacter i ndologenes. Enzymologi a - 6:273-281.

Cain., R.B. and S.M. King, 1979. L i k e l y rec ru i tmen t o f t h e c i t r a t e - t r a n s p o r t

system f o r t h e uptake of a range o f detergent bu i l de rs . 618 Proc. Soc. Gen.

M i c r o b i o l . Mtg. Cambridge, Ap r i 1, 1979.

Cody, R.M. and R.G. Tischer, 1963. O x i d a t i v e metabolism o f c i t r a t e and

1 ac ta te by Pseudomonas aeruginosa and S e r r a t i a ind ica . Develop. Ind.

Microbial. - 5:312-315.

Dagley, S., 1954. D i s s i m i l a t i o n o f c i t r i c a c i d by A. aerogenes and E. c o l i .

J. Gen. M i c r o b i o l . - 11:218-227.

Dagley, S. and E.A. Dawes, 1953. D i s s i m i l a t i o n o f c i t r i c a c i d by b a c t e r i a l

ex t rac t s . Nature - 172:345-346.

F i res tone, M.K. and J.M. Tiedje, 1978. Pathway o f degradat ion o f N i t r i l o -

tri acetate by a Pseudomonas species. Appl . Environ. M i c r o b i o l . . - 35:955-961.

G l edhi 11, W. E., 1976. Mic rob i a1 degradat ion o f carboxymethyl t a r t rona te .

Abstract Q65. . ~ n n . Mtg. Amer. Soc. Mic rob io l . P. 201.

IJC Report on Eco log ica l E f f e c t s o f Non-Phosphate Detergent Bui 1 ders, F i n a l

Report on NTA, 1978. I n t e r n a t i o n a l J o i n t Commission, Great Lakes Science

~ d v i s o r ~ Board.

Kornberg, H.L. and A.M. Gotto, 1961. The Metabolism of C2 compounds i n

microorganisms. Synthesis o f c e l l cons t i t uen ts f rom g l y c o l l a t e by pseudomonas

sp. Biochem. J. 78:69-82. -

Kornberg, H.L. and H.A. Krebs, 1957. Synthesis o f c e l l cons t i t uen ts f rom C 2

u n i t s by a mod i f i ed t r i c a r b o x y l i c ac id cycle. Nature - 179:988-991.

Lever Brothers Coinpany, 1977. CMOS - An Empi r ica l Isomer o f c i t r i c a c i d f o r

use as a detergent b u i l d e r - r e p o r t on i t s s a f e t y and environmental impact,

presented t o t h e IJC Task Force on the Eco log ica l E f f e c t s o f Non-Phosphate

Detergent Bu i lders .

Ludeweig, J., B. Verlnesland and A. Dorfman, 1961. The mechanism o f ac t i on o f

hyaluronidases. J. B i o l . Chem. - 236:333-339.

Monsanto I n d u s t r i a l Chemicals Company, 1978. Bu i l de r M, environmental and

human safety, presented t o t h e IJC Task Force on t h e Eco log ica l E f f e c t s o f

Non-Phosphate Detergent Bui 1 ders.

Mi les Laborator ies, Inc., P f i ze r , Inc., and Proc ter and Gamble Co. 1977. The

environmental s a f e t y o f c i t r a t e . Presenta t ion t o t h e IJC Task Force on t h e

Ecological E f f e c t s of Non-Phosphate Detergent Bui lders .

O'Brien, R.W. and J.R. Stern, 1969. Requirement f o r sodium i n t h e anaerobic

growth o f aerobacter aerogenes on c i t r a t e . J. Bact. - 98:388-393.

Peterson, D. and J. Llaneza, 1974. I d e n t i f i c a t i o n o f a carbon-oxygen lyase

a c t i v i t y c leav ing the e ther 1 inkage i n carboxymethyloxysuccinic Acid. Arch.

Biochem. Biophys. =:135-146.

Smith, A.J., J. London and R.Y. Stanier , 1967. Biochemical bas i s o f o b l i g a t e

autot rophy i n b l ue-green algae and t h i o b a c i 11 i. J. B a c t e r i o l . - 94:972-983.

S tan ie r , R.Y., N. P a l l e r o n i and M. Doudoroff, 1966. The aerobic

pseudomonads: a taxonomic study. J. Gen. M ic rob io l . - 43:159-271.

S ta r r , M.P. and F. Moran, 1962. E l - i ~ n i n a t i v e s p l i t o f p e c t i c substances by .' phytopathogenic s o f t - r o t bac te r i a . Science 135:920-921.

Swim, H.E. and L.O. Krampitz, 1954. Ace t i c a c i d o x i d a t i o n by Escher ich ia

c o l i: Evidence f o r t h e occurrence o f a t r i c a r b o x y l i c a c i d cyc le. J.

B a c t e r i o l . - 67:419-425.

Viccaro, J.P. and E.L. Ambye, 1977. Anaerobic b i o d e g r a d a b i l i t y o f

carboxynethyloxysuccinate, a detergent bu i l de r . J. Am. O i 1 Chem. Soc.

54:41-46. -

V i l 1 arreal-Moguel , E. I. and J. Ruiz-Herrera, 1969. I n d u c t i o n and p r o p e r t i e s

o f t h e c i t r a t e t r a n s p o r t system i n Aerobacter aerogenes. J. Bact. - 98:522-558.

Wil lecke, K. and A. Pardee, 1971. I n d u c i b l e t r a n s p o r t o f c i t r a t e i n a

gram-posi t ive bacter ium b a c i l l u s s u b t i l i s . J. B i o l . Chem. - 246:1032-1040.

EFFECTS ON MANAGEMENT OF MUNICIPAL WASTEWATERS

I NTRODUCTI ON

Eva lua t i on o f t he p o s s i b l e environmental e f f e c t s o f o rgan ic de te rgen t

b u i l d e r s r e q u i r e s c o n s i d e r a t i o n o f bo th t h e e f f e c t o f wastewater t r ea tmen t

processes on o rgan ic b u i l d e r s and t he i n f l u e n c e o f t h e o rgan ic b u i l d e r s on t h ?

performance o f wastewater t rea tment f a c i l i t i e s . The e v a l u a t i o n i s compl i ca ted

by t h e f a c t t h a t a l a r g e v a r i e t y o f phys i ca l , chemical, and b i o l o g i c a l

wastewater t rea tment processes are c u r r e n t l y i n use and may be a n t i c i p a t e d t o

be used i n t h e f u t u r e . Futhermore, household wastewater management systems

(as opposed t o mun ic ipa l systems) a re used i n many r u r a l and suburban areas o f

t h e N o r t h American con t i nen t . A n t i c i p a t e d e f f e c t s o f these mun ic ipa l and

household systems on o rgan ic b u i l d e r s and o f t h e b u i l d e r s on t h e t r ea tmen t

systems are cons idered i n t h i s Chapter.

REMOVAL DURING TREATMENT

PRIMARY TREATMENT . .

No i n f o r m a t i o n on removal o f c i t r a t e , CMOS, o r CMT i n p r ima ry wastewater

t rea tment i s known t o e x i s t and t h e i r l o s s by a s s o c i a t i o n w i t h sediment ing

s o l i d p a r t i c l e s would n o t be expected t o be p reva len t . For example, because

v e r y l i t t l e CMOS removal occur red i n s e p t i c tanks, K l e i n and Jenk ins (1972)

i n f e r r e d t h a t CMOS was p o o r l y sorbed on sewage p a r t i c l e s . Furthermore, i n

s tud ies of anaerobic d i g e s t i o n o f p r ima ry sludge, V iccaro and Ambye (1977)

found t h a t o n l y 1.9 percen t o f added CMOS was assoc ia ted w i t h t h? s l u d g s

s o l i d s , and t h e y a t t r i b u t e d t h i s t o b i o l o g i c a l a s s i m i l a t i o n . F i n a l l y ~ o n s a n t o

(1978) r e p o r t e d t h a t o n l y smal l amounts o f CMT adsorbed on p r ima ry s ludge

s o l i ds .

I f removal o f t h e o rgan ic b u i l d e r s does n o t occur, e f f l u e n t from p r ima ry

t rea tment f a c i l i t i e s w i l l c o n t a i n them a t t h e i n f l u e n t concen t ra t ion . . .

Furthermore, t h e l i q u i d phase o f s ludge withdrawn f r om p r ima ry sed imenta t ion

bas ins w i l l c o n t a i n t h e o rgan i c b u i l d e r s a t about t h e same c o n c e n t r a t i o n as

e x i s t e d i n t h e raw wastewater. Thus, t h e o rgan ic b u i l d e r s would reach s ludge

t rea tment processes and, un less b u i 1 ders were removed by those processes, t h e y

would be conveyed, to u l t i m a t e s ludge u t i l i z a t i o n o r d i sposa l s i t e s .

AEROBIC BIOLOGICAL TREATMENT

Aerobic b i o l o g i c a l processes represen t by f a r t h e most p r e v a l e n t c u r r e n t

and a n t i c i p a t e d f u t u r e means f o r secondary mun ic ipa l wastewater t rea tment

(U.S. Environmental P r o t e c t i o n Agency, 1977) and may be expected t o have t h e

g r e a t e s t i n f l u e n c e on t h e amount o f o rgan i c de te rgen t b u i l d e r s re l eased t o t h e

environment.

Less concern e x i s t s about t h e b i o d e g r a d a b i l i t y o f c i t r a t e than o f t h e

o the r two o rgan ic b u i 1 ders cons idered i n t h i s r e p o r t (see p rev ious s e c t i o n ) .

C i t r i c a c i d i s a c o n s t i t u e n t o f human u r i n e (Thunberg, 1953) and i s found i n

raw sewage ( P a i n t e r and Viney, 1959). I t i s a l s o a common me tabo l i c

in te rmed ia te . C i t r a t e degradat ion occurs i n aerob ic b i o l o g i c a l wastewater

t rea tment p l a n t s whether o r n o t c i t r a t e i s used as a de te rgen t b u i l d e r .

E f f e c t i v e removal o f c i t r a t e i n aerobic b i o l o g i c a l processes would be expected

w i t h o u t t h e need f o r p r i o r acc l imat ion , and, indeed, exper ience has con f i rmed

this(Shannon and Kamp, 1973).

On t h e o t h e r hand, whi 1 e V iccaro and Ambye (1977) have genera l i z e d t h a t

"CMOS i s r e a d i l y and comple te ly b iodegradable i n aerob ic environments", p r i o r

acc l ima t i on o f b i o l o g i c a l popu la t ions t o CMOS i s necessary (see p rev ious

sec t i on ) . I n a s tudy r e p o r t e d t o t h e Task Force by Lever (1977), r esp i rome te r

da ta i n d i c a t e d no degradat ion o f CMOS by an unacc l imated a c t i v a t e d sludge, b u t

i n p a r a l l e l s t ud ies w i t h adapted sludges s i g n i f i c a n t removals occurred. I n

1 abora to ry a c t i v a t e d s ludge systems descr ibed by Lever, acc l imat i o n ( g r e a t e r

than 95 percen t CMOS degradat ion) was achieved i n 5 days a t 15OC and 7 days

a t 5OC. The need f o r adap ta t ion o f b i o l o g i c a l popu la t i ons t o CMOS i n

wastewater t rea tment i s i 11 u s t r a t e d by p l an t -sca le da ta presented by Lever

(1977). A t a New Jersey a c t i v a t e d s ludge wastewater t rea tment p l an t , a

maximum o f 30 percen t CMOS was removed d u r i n g a 7-day s tudy per iod . K l e i n and

Jenkins (1972) r e p o r t e d t h a t 140 days were r e q u i r e d be fo re removal o f CMOS

occurred i n an o x i d a t i o n pond r e c e i v i n g 15 mg/L of CMOS. Removals approaching

90 percent were no t r e a l i z e d i n a pond r e c e i v i n g 30 mg/L o f CMOS u n t i l a f t e r

185 days. K l e i n and Jenkins a t t r i b u t e d the long pe r i od o f acc l ima t i on

requ i red t o low temperatures a t t h e beginning of t h e experiment, and concluded

t h a t CMOS degradat ion was v i r t u a l l y complete i n w e l l operated o x i d a t i o n ponds

a t temperatures o f about 6OC o r more. It must be noted, however, t h a t

because o f t h e i r l a r g e sur face area, shal low depth, and long r e t e n t i o n t ime,

o x i d a t i o n ponds l oca ted i n h igh l a t i t u d e s c h a r a c t e r i s t i c a l l y operate a t low

temperatures dur ing extended per iods o f t h e year.

Acc l imat ion t o CMOS was found i n t h e Lever (1977) s tud ies t o be in f luenced

adversely by 1 ow d isso lved oxygen concentrat ions. When semi-cont i nuous

a c t i v a t e d sludge u n i t s were operated i n t h e l a b o r a t o r y a t d isso lved oxygen

concent ra t ions o f 0.8 mg/L, 11 days were requ i red f o r CMOS adaptat ion, w h i l e

t h e same degree o f degradat ion was achieved w i t h i n 2 t o 3 days when t h e

d isso lved oxygen concent ra t ion approached s a t u r a t i o n (about 8 mg/L). Th i s

e f f e c t o f d isso lved oxygen on acc l ima t i on cou ld be s i g n i f i c a n t i n many

b i o l o g i c a l wastewater t reatment processes. Indeed, t h e . l a c k o f success i n

achiev ing acc l ima t i on t o CMOS a t t h e New Jersey a c t i v a t e d sludge t reatment

p l a n t was suspected t o have been caused by low d isso lved oxygen concent ra t ions

(Lever, 1977). Low d isso lved oxygen concent ra t ions are common i n mun ic ipa l

a c t i v a t e d sludge wastewater t reatment p l a n t s e i t h e r because o f l i m i t e d

oxygenat ion capac i t y o r because p l a n t managers recognize t h a t maximum gas

t r a n s f e r e f f i c i e n c y (and minimum energy consumption) i s achieved by ope ra t i ng

a t low d isso lved oxygen concentrat ions. Aside from t h e recen t suggest ion

(Sezgin -- e t a l . 1978) t h a t low d isso lved oxygen concent ra t ions might cause

adverse a c t i v a t e d sludge s e t t l e a b i l i t y , maintenance of r e l a t i v e l y low

d isso lved oxygen concent ra t ions i n ae ra t i on tanks a t a c t i v a t e d sludge p l ants

has no t been considered t o be undes i rab le - indeed, i t i s an ope ra t i ona l goal

a t many p lan ts .

Whi le a v a i l a b l e i n fo rma t i on i n d i c a t e s t h a t p r o p e r l y c o n t r o l l e d acc l imated

aerobic wastewater t reatment systems can be operated under steady s t a t e

cond i t i ons w i t h h igh degrees o f CMOS removal, r e a l wastewater t reatment p l a n t s

operate w i t h s i g n i f i c a n t v a r i a t i o n i n parameters which cou ld i n f l u e n c e t h e

maintenance o f a popu la t i on o f organisms acc l imated t o CMOS. Thus, i f CMOS i s

used as a detergent builder it should be with the realization that CMOS would, at times, be discharged from aerobic biological wastewater treatment plants at essentially the same concentration as contained in the raw sewage. Because of

the influences of .variables such as wastewater flow rate, temperature, and dissolved oxygen concentration, difficulties in achieving and continuously maintaining an accl imated population of organisms capable of degrading CMOS would seem inevitable at some locations.

As indicated in the previous section, essentially complete removal of CMT

in 1 aboratory biological treatment units has been demonstrated - but only after substanti a1 periods of accl imati on (Monsanto, 1978). In control led,

semi-continuous laboratory activated sludge units, acclimation times on the order of 4 to 9 weeks were reported. Seven to ten weeks of acclimation were reported to be necessary in controlled continuous flow units receiving raw sewage with 25 mg/L of added CMT. Temperature influenced accl imation time - in activated slude units in which acclimation was achieved in 5 weeks at 18 to 20°C, 17 weeks was required to achieve acclimation at 6OC. Similarly, Barth, -- et al. (1979) found that an acclimation period of 14 weeks was required before effluent degradation of carboxymethyltartronate (the major constituent of CMT) occurred.

1 An impurity in CMT, diglycolate, is reported by Monsanto (1978) to be 1 biodegradable. Monsanto also has reported that a second impurity,

1 d i tartronate, which comprises 7 percent of the total polycarboxyl ate content

( of CMT, is not biologically degraded under aerobic conditions.

Available information on CMT indicates that the. same cautions contained in

the discussion of CMOS concerning the inevitable discharge of the organic builder from aerobic biological wastewater treatment plants apply to the

carboxymet hyl t artronate and di glycol ate contents of CMT. Furthermore, additional caution should be noted because of the apparently longer periods of

time required to achieve acclimation to carboxymethyltartronate, and because - no removal of ditartronate apparently can be expected in aerobic biological

treatment facilities.

1 It should be noted that the biodegradability of the three builders might

be a l t e r e d by complexat ion w i t h heavy meta ls . Th is s u b j e c t i s d iscussed i n

t h e n e x t sec t ion . . . .

PHYSICOCHEMICAL TREATMENT

A t some mun ic ipa l t rea tment p l an t s , physicochemical processes a re used i n

p l ace of more conyent iona l b i o l o g i c a l processes. Such a p l a n t , m igh t make use

o f such processes as chemical coagu la t i on f o r removal o f c o l l o i d a l and

suspended p a r t i c l e s , chemical p r e c i p i t a t i o n f o r phosphorus removal, adso rp t i on

on a c t i v a t e d carbon, e tc . Whi le some b i o l o g i c a l removal o f b iodegradable

b u i l d e r s m igh t occur a t such p l a n t s by acc l imated popu la t i ons e s t a b l i s h e d

w i t h i n t h e a c t i v a t e d carbon adsorp t ion system, i t i s o f i n t e r e s t t o cons ider

removal of t h e b u i l d e r s by t h e phys i ca l and chemical mechanisms.

Monsanto (1978) r e p o r t e d t h a t a c t i v a t e d carbon was capable o f removing

l e s s than 20 percen t o f CIYT. N i n e t y percen t removal o f carboxymethyl-

t a r t r o n a t e ( t h e major c o n s t i t u e n t o f CMT) was r e p o r t e d by Barth, -- e t a l . (1978)

when t h e pH was 3, b u t much lower degrees o f removal were achieved a t pH

va lues more t y p i c a l l y found i n wastewater t r ea tmen t p l an t s . Data on removal

of o the r o rgan ic b u i l d e r s by a c t i v a t e d carbon a re n o t known t o e x i s t . Based

on s t r u c t u r a l s i m i l a r i t S e s c f c i t r a t e and ClYOS t o CMT, s i g n i f i c a n t removal o f

them by a c t i v a t e d carbon adso rp t i on would n o t be expected t o occur.

SLUDGE MANAGEMENT PROCESSES

The t rea tment processes cons idered i n t h e p rev ious t h r e e s e c t i o n s a l l ' .

produce res idues c o n s i s t i n g o f suspensions o f s o l i d s i n 1 i q u i d (s ludges) . As

descr ibed i n p rev ious sect ions, t h e e x t e n t t o which t h e t h r e e o rgan ic b u i l d e r s

would be i nc l uded p r e f e r e n t i a l l y i n t h e s o l i d phase o f s ludges i s unknown, b u t

i s l i k e l y t o be s l i g h t . However, t h e l i q u i d phase o f t h e s ludges would

c o n t a i n t h e b u i l d e r s a t t h e concen t ra t i ons a t which t h e y e x i s t e d i n t h e

t r ea tmen t process f rom which t h e s ludge was produced. I n t h e case o f p r ima ry

t reatment , physicochemical processes, o r unacc l imated b i o l o g i c a l processes f o r

CMOS o r CMT t h i s concen t ra t i on would be assumed t o be e s s e n t i a l l y t h a t of t h e

raw wastewater.

Sludge management processes which migh t be expected t o have some e f f e c t on

t h e b u i l d e r s i n c l u d e b i o l o g i c a l s t a b i l i z a t i o n and combustion. I t i s assumed

t h a t t h e b u i l d e r s would be dest royed i n combustion, and t h a t t h e i r f a t e i n

aerobic b i o . l og i ca1 s t a b i 1 i z a t i o n would be t h e same as descr ibed e a r l i e r f o r

aerob ic b i o l o g i c a ' l t reatment . The f a t e o f t h e t h r e e b u i l d e r s i n anaerobic

d i ges t i on , a common means f o r b i o l o g i c a l s t a b i l i z a t i o n of s ludges, remains t o

be cons i dered.

D i f f i c u l t i e s w i t h b i o l o g i c a l degradat ion o f c i t r a t e under anaerobic

c o n d i t i o n s would no t be expected (p rev ious s e c t i o n ) and a re n o t known t o have

been experienced. V iccaro and Ambye (1977) i n v e s t i g a t e d t h e b i odegradabi 1 i ty

of CMOS i n l a b o r a t o r y anaerobic d i g e s t e r s and r e p o r t e d t h a t CMOS degrada t ion

began a f t e r an a c c l i m a t i o n p e r i o d of 6 days and t h a t a f t e r 14 days o f

ope ra t i on essen t i a1 l y complete d e s t r u c t i o n o f CMOS was be ing achieved.

Monsanto (1978) r e p o r t e d t h a t no degradat ion o f carboxymethyl t a r t r o n a t e ( t h e

major c o n s t i t u e n t of CMT) occur red under anaerobic cond i t i ons .

Fo l l ow ing t rea tment by t h e above processes sludges a re t y p i c a l l y

1 andf il led, appl i e d t o a g r i c u l t u r a l land, o r d ischarged a t sea. P o t e n t i a l

environmental e f f e c t s f rom l a n d f i l l i n g i n c l u d e l e a c h i n g o f o rgan ic b u i l d e r s t o

ground o r s u r f ace waters.

The f a t e of o rgan ic b u i l d e r s i n mar ine environments i s cons idered i n t h e

next sect ion.. Discharges o f s ludge a t sea f r e q u e n t l y would be from tankers o r

barges and thus i n t o unacc l imated waters. The f a t e o f b u i l d e r s i n t h e sludges

a p p l i e d t o 1 and would be expected t o be s i m i l a r t o t h a t o f b u i l d e r s i n

wastewaters a p p l i e d t o land, as cons idered i n t h e f o l l o w i n g sec t i on . I t .

should be noted, however, t h a t s ludge a p p l i c a t i o n t o a g iven p l o t of l a n d

t y p i c a l l y occurs a t l e s s f r equen t i n t e r v a l s (annual ly , o r even l e s s f r equen t )

than wastewater a p p l i c a t i o n and thus t h e development o f a p o p u l a t i o n o f

a c c l i m a t e d ' s o i l b a c t e r i a a t a s ludge a p p l i c a t i o n s i t e seems doub t f u l .

LAND A P P L I C A T I O N SYSTEMS

B i o l o g i c a l mechanisms p l a y an impor tan t r o l e i n d e s t r u c t i o n o f o rgan i c

compounds i n s o i l . Accord ing ly , cons ide ra t i ons o f b i o d e g r a d a b i l i t y under

aerobic and anaerobic cond i t i ons as descr ibed i n t h e prev ious sec t i on and i n

preceding sec t ions of t h i s chapter are a p p l i c a b l e t o cons ide ra t i on o f t h e

performance o f land a p p l i c a t i o n systems.

C i t r a t e i s a normal c o n s t i t u e n t o f s o i l s and would be degraded. K l e i n and

Jenkins, (1972) repo r ted t h a t acc l imat ion o f aerobic s o i l organisms t o CMOS

occurred a f t e r two weeks o f exposure i n s e p t i c tank t i l e f i e l d s . Monsanto

(1978) demonstrated b iodegradat ion o f CMT i n aerob ic s o i l s - a1 b e i t over a

s u b s t a n t i a l t ime period. Based on p r e v i o u s l y discussed data, i t would be

a n t i c i p a t e d t h a t i n anaerobic s o i 1 environments (produced, f o r example, by

f l ood ing ) c i t r a t e would be b i o l o g i c a l l y degraded, CMOS would be degraded i f

acc l imat ion had occurred, and CMT would n o t be degraded.

HOUSEHOLD WASTEWATER TREATMENT SYSTEMS

Typ i ca l l y , i n d i v i d u a l household systems are comprised o f an anaerobic tank

( " s e p t i c tank" ) f o l l owed by a s o i l p e r c o l a t i o n f i e l d which i s in tended t o be

aerobic. The anaerobic stage i s p r i m a r i l y f o r s o l i d s separa t ion and

s o l u b i l i z a t i o n and i t would be expected t h a t so lub le organic b u i l d e r s would

reach t h e s o i l system a t e s s e n t i a l l y t h e same concent ra t ion as they e x i s t e d i n

t h e raw waste, Indeed, K l e i n and Jenkins (1972) found t h a t t h e concen t ra t i on

o f CMOS d i d no t change i n s e p t i c tanks w i t h a 2 day nominai r e t e n t i o n t ime.

I n t h e p e r c o l a t i o n f i e l d , t h e same cons idera t ions as descr ibed i n t h e prev ious

sec t i on on land a p p l i c a t i o n would apply except t h a t two d i f f e rences migh t be

an t i c i pa ted : (1 ) e s t a b l ishment o f an acc l imated b i o l o g i c a l popu la t i on should

occur because t h e p e r c o l a t i o n f i e l d i s a permanent i n s t a l l a t i o n , and ( 2 )

anaerobic cond i t i ons (under which degradat ion o f CMT would n o t be expected)

would probably 52 more common than du r i ng l and a p p l i c a t i o n because o f c l ogg ing

problems i n household p e r c o l a t i o n systems.

EFFECTS O F B U I L D E R S ON WASTEWATER TREATMENT

INTRODUCTION

None o f t he th ree b u i l d e r s considered i n t h i s r e p o r t are known t o have 'an

adverse e f f e c t on biochemical oxygen demand o r suspended s o l i d s removal

e f f i c i e n c i e s o f wastewater t rea tment p l an t s . Shannon (1975) s p e c i f i c a l l y

noted t h a t c i t r i c a c i d had no adverse e f f e c t s on removal o f b iochemica l oxygen

demand, and i n s p e c t i o n o f a v a i l a b l e r e s u l t s o f s t u d i e s w i t h CMOS and CMT does

no t r evea l a de t r imen ta l i n f l u e n c e on t rea tment p l a n t performance. However,

increases i n s o l u b l e o rgan i c carbon i n t r e a t e d e f f l u e n t would be expected f r om

t h e presence o f CMOS o r CMT du r i ng pe r i ods when an acc l imated p o p u l a t i o n o f

microorganisms cou ld n o t be ma in ta i ned . I t i s t o be a n t i c i p a t e d t h a t these

per iods o f CMOS o r CMT d ischarge would occur n o t o n l y because o f absence o f

acc l ima t i on immediate ly f o l l o w i n g i n t r o d u c t i o n o f CMOS o r CMT, b u t a1 so as a

r e s u l t o f l o s s o f acc l ima t i on due t o f a c t o r s such as low temperatures, h i gh

h y d r a u l i c loadings, o r o the r adverse ope ra t i ona l cond i t i ons . Also, a l l t h r e e

of t h e b u i l d e r s cons idered i n t h i s r e p o r t would c o n t r i b u t e t o t h e o rgan i c

con ten t o f t h e e f f 1 uents o f phys i cochemical wastewater t rea tment p l a n t s . I n

t h e case o f c i t r a t e , t h i s o rgan ic carbon would be de tec ted as b iochemica l

oxygen demand. CMT and CMOS would escape d e t e c t i o n as b iochemica l oxygen

demand unless an acc l imated popu la t i on o f organisms were a v a i l a b l e f o r t h e

bioassay.

K l e i n and Jenk ins (1972) noted t h a t CMOS caused a chang; i n a l g a l spec ies

i n an o x i d a t i o n pond, b u t t h e e f f e c t on waste t rea tment i s unknown.

CMOS was r e p o r t e d by Viccaro and Ambye (1977) t o have no e f f e c t on t h e

performance o f a l a b o r a t o r y anaerobic d i g e s t i o n u n i t .

TRANSPORT OF HEAVY METALS

Because o f t h e a b i l i t y o f o rgan ic b u i l d e r s t o complex metals, (see s e c t i o n

on chem is t r y ) i t i s reasonable t o cons ider whether t h e y cou ld i nc rease t h e

heavy meta l con ten t o f t r e a t e d e f f luen ts . Shannon (1975) r e p o r t e d t h a t use o f

c i t r a t e as a b u i l d e r d i d no t cause t r a n s p o r t o f heavy meta ls th rough an

a c t i v a t e d s ludge t rea tment system even under w i n t e r c o n d i t i o n s i n Canada.

E f f e c t s o f CMOS and CMT on meta l t r a n s p o r t a re n o t known.

Metal t r a n s p o r t would be expected t o be maximized when removal o f t h e

b u i l d e r was i n e f f e c t i v e . Th i s would occur w i t h a l l t h r e e b u i l d e r s i n

physicochemical t reatment p l a n t s and w i t h CMOS and ClYT d u r i n g pe r i ods when

accl imat ion was not maintained a t b i o l o g i c a l treatment p lants. S i m i 1 a r l y ,

m o b i l i z a t i o n o f heavy metals i s poss ib le i n s o l i d systems r e c e i v i n g wastewater

o r sludges conta in ing CMOS o r CMT.

PHOSPHORUS REMOVAL

I n j a r t e s t s .with raw sewage, Shannon -- e t a1 . (1977) found t h a t t he

presence o f c i t r a t e reduced the a b i l i t y o f f e r r i c ch lor ide , alum, and l ime t o

p r e c i p i t a t e phosphorus. They concluded t h a t i f detergents were b u i l t w i t h

c i t r a t e , t he amount o f f e r r i c ch lor ide , lime, o r alum requ i red t o achieve a

given degree o f phosphorus removal would increase. For example, s tud ies

reported by Shannon and h i s coworkers i nd i ca ted t h a t t h e amount o f alum

requ i red t o achieve an e f f l u e n t l eve l o f 1 mg/L o f phosphorus would increase

by 67 percent i n t h e presence o f 10 mg/L o f c i t r a t e . Shannon -- e t al . reported,

however, t h a t when phosphorus removal was c a r r i e d out dur ing secondary

treatment no in te r fe rence f rom c i t r a t e occurred. This was because t h e c i t r a t e

was degraded dur ing the course o f secondary treatment.

Studies o f t he e f f e c t o f CMOS and CMT on phosphorus p r e c i p i t a t i o n are not

known. If the e f f e c t o f t he l a t t e r two b u i l d e r s i s assumed t o be comparable

t o t h a t o f c i t r a t e , they might a1 so cause in te r fe rence w i t h phosphate

removal. Under any o f t he f o l l o w i n g condi t ions, then, i n te r fe rence o f organic

b u i l d e r s w i t h phosphorus removal could occur: (1) p r e c i p i t a t i o n o f phosphorus

i n pr imary treatment, (2 ) p r e c i p i t a t i o n i n physicochemical treatment, and ( 3 )

p r e c i p i t a t i o n o f phosphorus i n secondary treatment when accl imat ion of

organisms t o CMOS o r CMT was not being maintained.

COSTS

Although the exact amounts are not known, increased treatment costs are

l i k e l y t o r e s u l t from use o f t h e organic bu i l de rs . A l l t h ree w i l l r e q u i r e use

o f more oxygen and r e s u l t i n product ion o f more sludge i n b i o l o g i c a l

treatment. I n the case o f CMOS more oxygen may be requ i red t o achieve o r t o

main ta in acc l imat ion i n aera t ion tanks. The presence o f undegraded b u i l d e r i s

a lso l i k e l y t o r e s u l t i n increased costs f o r chemicals t o p r e c i p i t a t e

phosphate. Increased costs f o r moni tor ing are possible.

SUMMARY .

C I TRATE

1. C i t r a t e i s a n a t u r a l l y o c c u r r i n g o r g a n i c compound a l r e a d y f o u n d i n

m u n i c i p a l wastewaters. I t would be expected t o be removed i n c o n v e n t i o n a l

secondary wastewater t r e a t m e n t f a c i l i t i e s w i t h o u t t h e need f o r

a c c l i m a t i o n .

2. No i n f o r ~ n a t i o n i s a v a i l a b l e on t h e removal o f c i t r a t e i n phys icochemica l

wastewater t r e a t m e n t systems. It i s l i k e l y t h a t t h e e f f l u e n t b iochemica l

oxygen demand o f phys icochemica l wastewater t r e a t m e n t systems would be

increased. - ,

3. I nc reased q u a n t i t i e s of chemica ls would be - r e q u i r e d t o p r e c i p i t a t e

,phosphorus, , if . such p r e c i p i t a t i o n were .a t tempted p r i o r t o b i o l o g i c a l

removal o f c i t r a t e .

4.. Use, of c i t r a t e as, a s u b s t i t u t e , f o r phosphorus may r e s u l t i n i n c r e a s e d

t r e a t m e n t . c o s t s ., ., .

CMOS. . .

1. CMOS can be removed by ae rob ic b i o l o g i c a l t r e a t m e n t processes, b u t

a c c l i m a t i o n i s r e q u i r e d . If a c c l i m a t i o n i s l o s t as a r e s u l t of such

f a c t o r s as n o t e d i n ( 2 ) , d i s c h a r g e of CMOS wi 11 occur.

2. Even i f a c c l i m a t i o n i s r e t a i n e d , CMOS removal i s l e s s e f f e c t i v e a t l o w

d i s s o l v e d oxygen c o n c e n t r a t i o n s , l o w temperatures , h i g h h y d r a u l i c l oad ing ,

and d u r i n g o p e r a t i o n a l upsets .

3. Removal o f ClYOS i n phys icochemica l t r e a t m e n t f a c i l i t i e s i s n o t known t o

occur .

4. E f f e c t s o f CMOS on phosphorus removal a r e n o t known.

CMT

1.

CMOS may mobi 1 i z e metal s i n unaccl imated b i o l og i ca l wastewater treatment

p l a n t s and s o i l systems r e c e i v i n g wastewaters o r sludges.

.. . . .

Use o f CMOS a s a s u b s t i t u t e f o r phosphorus may r e s u l t i n i.ncreased < . . . . , . . . . . .

t reatment costs.

The major cons t i t uen t o f CMT, carboxymethyl t a r t rona te , can be degraded i'n

aerobic b i o l o g i c a l wastewater t reatment p lan ts . However, long acc l ima t ion

per iods are requi red. Acc l imat ion might be l o s t due t o p l a n t opera t ing - cond i t ions w i t h t h e r e s u l t t h a t t h e organic b u i l d e r would be discharged i n

t r e a t e d eff 1 uent.

An i m p u r i t y i n CMT, d i t a r t r o n a t e , i s apparent ly no t biodegradable; nor i s

i t known t o be removed by o ther wastewater t reatment processes. A v a i l a b l e

data i n d i c a t e t h a t i t would be contained i n e f f l u e n t s .

Carboxynethyl t a r t r o n a t e i s no t known t o be biodegradable under anaerobic

condi t ions. It cou ld f i n d i t s way t o unaccl imated s o i l s f o l l o w i n g

anaerobic d iges t i on o f sludges from wastewater treatment p lan ts .

CMT i s not removed by ac t i va ted carbon adsorpt ion and would remain i n t h e

e f f l u e n t f rom physicochemical wastewater t reatment f a c i l i t i e s .

Metal m o b i l i z a t i o n i n unaccl imated wastewater treatment p lan ts an,d s o i l s

systems might occur.

E f f e c t s o f CMT.on phosphorus p r e c i p i t a t i o n are unknown. Presumably i t

could increase , chemical , requirements.

Use o f CMT as, a s u b s t i t u t e f o r phosphorus may r e s u l t i n increased

treatment costs.

REFERENCES

Barth, E.F., H.H.. Tabak, and C. I. Mashi. B iodegradat ion s tud ies o f

carboxymethyl t a r t rona te , U. S. Environmental P r o t e c t i o n Agency Report,

EPA-600/2-78-115, 35 pp.

K le in , S.A., and D. Jenkins, 1972. The f a t e o f carboxymethyloxysuccinate i n

s e p t i c tank and o x i d a t i o n pond systems, San i ta ry Engineering Research

Laboratory, Report No. 72-10, u n i v e r s i t y o f C a l i f o r n i a , Berkeley, 55 pp.

Lever Brothers Company, 1977. CMOS - An Empi r i ca l Isomer o f c i t r i c a c i d f o r

use as a detergent b u i l d e r - r e p o r t on i t s s a f e t y and environmental impact,

presented t o t h e IJC Task Force on t h e Eco log ica l E f f e c t s o f Non-Phosphate

Detergent Bu i lders .

Monsanto I n d u s t r i a l Chemicals Company, 1978. B u i l d e r M, environmental and

human safety , presented t o t h e IJC Task Force on t h e ~ c o l o ~ i c a l ' E f f e c t s o f

Non-Phosphate Detergent Bu i lders .

~ a i n t e r , ' ~ . ~ . , and M. Viney.' C m ~ p o s i t i o n o f a domestic sewage, Jour. Biochem,

M ic rob io l . Tech. Eng., - 1 : 143-162.

Sezgin, M, D. Jenkins, and D. S. Parker, 1978. A u n i f i e d theo ry o f f i l amen-

tous a c t i v a t e d sludge bulk ing, Jour. Water P o l l . Cont. Fed., - 50:362-381

Shannon, E. E., and L. J. Kamp, 1973.. Detergent subst i t 'u ion s tud ies a t ,C:F.S.

Gloucester, Environmental P r o t e c t i o n Service, Report No. EPS4-WP-73-3, 139 pp. n

Shannon, E.E, 1975. E f fec ts o f detergent f o rmu la t i on on wastewater

c h a r a c t e r i s t i c s and treatment, Jour. Water Pol 1. Cont. Fed., - 47:2371-2383

Shannon, E.E., N. W. Schmidtke, and P. J.A. Fowlie, 1977. E f f e c t o f c i t r a t e

and carbonate based detergents on wastewater c h a r a c t e r i s t i c s and treatment.

Wastewater Techno1 ogy Centre, Environmental P r o t e c t i o n Service, Environment

Canada, 35 pp.'

Thunberg, T, 1953. Occurrence and s i g n i f i c a n c e o f c i t r i c a c i d i n t h e animal

organism. Physio l . Rev., %:I-12.

U.S. Environmental P r o t e c t i o n Agency, 1977. Cost est imates f o r c o n s t r u c t i o n

o f publ ic ly-owned wastewater t reatment f a c i l i t i e s , 1976 Needs Survey,

Summaries o f Technical Data.

Viccaro, J. P., and E. L. Ambye, 1977. Anaerobic b i o d e g r a d a b i l i t y o f

carboxymethyloxysuccinate, a detergent bu i l de r , - Jour. --- o f t h e Amer. - O i l

Chemists B., %:I, 41-46.

DEGRADATION IN THE ENVIRONMENT

Whi le s t u d i e s o f t h e environmental b iodegrada t ion o f t h e t h r e e b u i l d e r s ,

c i t r a t e , CMOS, and CMT, have been conducted under somewhat d i f f e r e n t

exper imenta l c o n d i t i o n s and by t he use o f d i f f e r e n t a n a l y t i c a l procedures, i t

i s ev i den t f rom a comparison o f t h e a v a i l a b l e r e s u l t s (Tab le 2 ) t h a t these

compounds are biodegraded w i t h d i f f e r e n t degrees o f readiness i n aerpbic

environments.

(i 1 FRESHWATER

C i t r a t e , as measured by a chem9cal ana lys is , d isappears r e a d i l y . . i n

f reshwater f r om ponds and f i s h tanks w i t h ve ry s h o r t l a g times^ and s h o r t

h a l f -1 ives. Such analyses must take i n t o cons ide ra t i on t he f a c t t h a t c i t r a t e

i s a w i d e l y d i s t r i b u t e d n a t u r a l product t h a t may a l ready be present i n amounts

up t o 0.2 mg/L ( M i l e s -- e t a l . 1977). B iodegrada t ion o f CMOS occurs somewhat

l e s s r e a d i l y and r e q u i r e s a s u i t a b l e p e r i o d f o r t h e es tab l i shment o f

acc l imated m i c r o b i a l popu la t ions . I n r i v e r die-away t e s t s i n which unadapted

u n s e t t l e d a c t i v a t e d sludge was a1 so present, acc l ima t i on occur red w i t h i n one

week and CMOS ( b y t h e c o l o r i m e t r i c procedure o f V iccaro and Ambye, 1973) was

undetec tab le a f t e r two weeks a t 24°C. Using "COL-formation f rom

14C- label l e d CMOS ( 1 abel l e d except f o r t he g l y c o l a t e methylene group) as a

measure .of degradat ion conf i rmed t h a t more than 90% re lease occur red i n 10

days (Lever, 1977). I n c o n t r a s t CMT r e q u i r e d s i g n i f i c a n t l y l onge r pe r i ods o f

t ime f o r t h e es tab l i shment o f s u i t a b l e b iodegrad ing m i c r o b i a1 populat ions. . i n

unsupplemented r i v e r waters. Whether measured by a f l u o r o m e t r i c procedure

(which i s based on c h e l a t i o n p r o p e r t i e s and p robab ly measures a l l t h e o rgan ic

components o f CMT), o r by 14C02 r e l e a s e f rom 14C-label- led carboxymethy- .%

l o x y t a r t r o n a t e (CMT) , slow disappearance o f CMT occur red over extended p e r i o d s

of 6-13 weeks. The presence o f raw sewage had a n e g l i g i b l e e f f e c t on

shor ten ing t h i s acc l imat t o n per iod. Once acc l imat i o n was achieved, however,

TABLE 2. BIODEGRADATION OF DETERGENT BUILDERS I N DIFFERENT AEROBIC ENVIRONMENTS

BUILDER

C i t r a t e

CMOS

CMT

ENVIRONMENT

Freshwater

E s t u a r i n e ' w a t e r

Mar i ne water

Soi 1

Freshwater

Es tua r ine water

Mar i ne water

S o i l

Freshwater

Es tua r ine water

Mar ine wa te r

. S o i l

Unadapted s 1 udge added, 20-100 mg/L

Perco la ted columns, 20-100 mg/L

Raw sewage . (5%) added weekly

Six d i f f e r e n t samples ( 50 ppm)

BIODEGRADATION

Up t o 5 hour lag. Rapid disappear- ance, h a l f - l i f e - o f 3-4 hours.

Rapid disappearance, h a l f - l i f e (0.6-3.0 hours) .

Disappearance repor ted.

Lag l e s s than 1 week, d isappear- ance e s s e n t i a l l y complete a t 2 weeks.

Ev ident a t 2-3 weeks, e s s e n t i a l l y complete a t 4-6 weeks.

Slow a c c l i m a t i o n over 5-12 weeks, then complete degradat ion o f a d d i t i o n s i n 1 week.

' ~ c c l imat ion r e q u i r e s 6-10 weeks.

A c c l i m i n a t i o n r e q u i r e s more than 15 weeks.

Acc l ima t ion r e q u i r e s 6-7 weeks.

Two day lag, v a r i a b l e r a t e s . From 50-100% complete a t 20 days.

REFERENCE

M i l e s e t al., 1977 --

Lever, 1977

K l e i n & Jenkins, 1972 Lever, 1977

Monsanto, 1978

fluorometric assay showed that subsequent additions of CMT were degraded in

one week. In lake water, periods as long as 6 weeks were again necessary for

the acclimation process. Since bacteria able to utilize CMT are not as

readily isolated as those utilizing citrate or CMOS, it appears that organisms

able to degrade carboxymethyltartronate are less widely distributed and may be

derived from a relatively small number of bacteria with the appropriate

enzymatic functions. Organisms able to degrade diglycol ate can be isolated

readily; aerobic begradation of this minor component of CMT (3%) is,

therefore, 1 i kely to occur readily. Studies with the ditartronate component,

on the other hand, showed that its biodegradation occurred with difficulty.

( i i ) ESTUARINE WATER '1

A similar pattern of biodegradation for two of the three builders is found

in these environments. Citrate degradation is rapid and complete whereas CMT

requires an acclimation period of at least 15 weeks before any degradation is

observed. No direct studies of CMOS degradation in estuary waters are

avail able for comparison, a1 though Cain has is01 ated microorganisms from

sal ine environments which possess the CMOS-cleaving enzyme (Weaver, J., personal communication).

( i i i ) SALT WATER

The only data available show that CMT is degraded but, as in other

environments, extended periods of 6-7 weeks are necessary before significant

degradation occurs.

(iv) SOILS

As for earlier-mentioned aerobic environments, the most extensive

documentation is on the behavior of CMT. Measurements of "TO2 release

(from '"C-label led CMOT) with six different soils showed different rates of

release after a lag time of about two days, with values suggesting from

50-100% degradation after 20 days. Substantial disappearance of citrate from

soil is reported to occur in seven days (Miles -- et al. 1977). The only reports

of CMOS degradation in soil are those carried out in percolation columns of

s o i l where anaerobic cond i t i ons are l i k e l y t o obta in. Under these cond i t i ons

2-3 weeks are necessary before onset of b iodegradat ion w i t h complete removal

a t 4-6 weeks (Lever, 1977). I n , short , a l l t h ree b u i l d e r s are degraded i n

s o i l , but t he experimental cond i t ions which have been employed are

s u f f i c i e n t l y va r i ed t h a t meaningful comparisons about t imes of acc l imat ion and

r a t e s o f disappearance cannot be made.

FACTORS AFFECTING BIODEGRADATION

I n Table 3 a re summarized the r e s u l t s o f var ious s tud ies on the e f f e c t s o f

anaerobic cond i t ions , lowered temperatures and var ious metal ions on b u i l d e r

degradation.

(4 ) ANAEROBIC CONDITIONS

While anaerobic cond i t i ons are no t an t i c i pa ted t o have any s i g n i f i c a n t

e f f e c t on c i t r a t e degradation, in fo rmat ion on i t s ac tua l environmental f a t e

under these cond i t i ons i s not ava i lab le . For CMOS, however, s tud ies made w i t h

pe rco la t i on columns o f s o i l by K l e i n and Jenkins (1972) and by s c i e n t i s t s a t

Lever (1977), show degradat ion i s i n i t i a t e d a f t e r 2-3 weeks and i s complete a t

4-6 weeks. I t s degradat ion i n anaerobic d iges tors was i n i t i a t e d w i t h s h o r t e r

l a g t imes and was complete a t two weeks. That anaerobic cond i t i ons were

achieved was ev ident from the demonstrated fo rmat ion o f methane f rom CMOS.

Lack o f s t r i c t l y anaerobic cond i t ions i n a sep t i c tank t o which CMT was

added may have accounted f o r i t s disappearance f rom t h i s system when, by

cont ras t , t h i s b u i l d e r was shown not t o undergo b iodegradat ion i n anaerobic

d igestors. A l t e r n a t i v e l y , i t s disappearance may have occurred i n t h e l a t e r

aerobic stages o f the s o i l p e r c o l a t i o n system which was p a r t of t he sep t i c

tank operat ion.

( i i ) TEMPERATURE

The p r i n c i p a l e f f e c t o f lowered temperatures on the b iodegradat ion o f

these b u i l d e r s i s on t h e t ime requ i red f o r t h e establ ishment o f accl imated

m ic rob ia l populat ions. Thus f o r CMOS a t 4OC i t s b iodegradat ion i n r i v e r

TABLE 3. EFFECTS OF PHYSICAL ANDCHEMICAL FACTORS ON BIODEGRADATION OF BUILDERS

FACTOR

Oxygen Limitation

Temperature

Metal Ions

CMOS ( ( i ) Anaerobic Digestors

BUILDER

Citrate

( i i ) Soil Percolation Columns

CONDITIONS'

-

CMT

CMT 1 6°-120C CFAS Units

( i ) Anaerobic Digestors ( i i ) Septic Tank

Ci trat:e

CMOS

-

4OC River Die-Away

( i i ) Fe ( I I I ) , Pb(I I ) , Cu(11) Hg(II), Zn(II ) , Cd(I1)

( i i i ) Cu(II), Hg(II), Zn(II), Cd( 11)

Ci t r a t e

CMT

( i ) Equimolar Cr(II1) and Hg( 11)

( i i ) Cu(II) , Ni(I1); Zn(II) , V( 1111, Mg( 111, Pb(II ) , Al ( I I I ) , F e ( I I I ) , Na(1)

( i ) Hg(II), C r ( I I I ) , Cu(11) ( i i ) Na(I), Ca(II) , Mg(II),

Fe ( I I ) , N i ( I I ) , Pb(I I ) , Zn(II ) , A l ( I I I ) , Cd(II1

No reports. Degradation Pre- sumed from Microbiology and Biochemistry.

EFFECT ON BIODEGRADATION

REFERENCE

Acclimation in 6 days; complete removal i ~ t 2 weeks. Biodegradation evident a t 2-3 weeks, essent ia l ly complete a t 4-6 week !; .

No inforraat ion. I i

Lever, 1977 . Klein & Jenkins, 1972 i

No demon:;trable hiodegradation. Degradat ion occurs, at tr ibuted to aerobic environment in so i l f ie ld .

Extended acclimation periods, Lever, 1977 10 weeks or more. I

Monsanto, 1978

Significdnt impairment of degradat ion. No signiU2icant ef fec t .

Extender1 acclimation from 5 wks. t o periods as long as 14 and 17 weeks respectively.

Signific,mt impairment of Lever, 1977 biodegradation in r iver water with added sludge. Affect r.ite of CMOS removal in fresh water. No degradation in estuarine water.

Inhibitory. Monsanto, 1978 No effect .

Monsanto, 1978

water r e q u i r e d an acc l ima t i on p e r i o d o f 10 o r more weeks, as cornpared t o a

p e r i o d o f approx imate ly one week a t 24OC. A somewhat sho r te r acc l ima t i on

p e r i o d was observed when popu la t ions were incubated a t 4OC a f t e r a p rev ious

adapta t ion a t 24OC (Lever, 1977). A s i m i l a r e f f e c t on acc l ima t i on o f

microorganisms f o r CMT degradat ion was found w i t h decreasing temperature, so

t h a t t h e extended per iods o f f i v e weeks o r more observed a t 20°C were

prolonged t o as l ong as 14 weeks a t 6OC (Monsanto, 1978). I n fo rma t i on on

t h e b iodegradat ion o f c i t r a t e a t 1 owered ten~peratures i s no t ava i l ab le . Such

da ta would p rov ide a use fu l comparison o f t h e behavior o f a n a t u r a l l y -

occu r r i ng ma te r i a1 a t low temperatures.

( i i i ) METAL IONS

As w i t h NTA, one o f t he concerns about t h e b iodegradat ion o f t h e

non-ni trogenous b u i l d e r s i s whether var ious o f t h e che la tes o f t h e d i f f e r e n t

b u i l d e r s are as r e a d i l y degradable as are t h e i r sodium o r potassium s a l t s . I n

view o f t h e slow environmental b iodegradat ion o f CMT a l ready r e f e r r e d to ,

f u r t h e r impairment o f b iodegradat ion o f i t s che la tes cou ld lead t o a s i g n i -

f i c a n t l e v e l of t h i s m a t e r i a l i n wastewater e f f l u e n t s and i n aqu i fe rs , a t

l e a s t du r i ng t h e i n i t i a l p e r i o d o f i t s widespread use. A l though n o t t e s t e d

d i r e c t l y as t h e che la ted species, CMT b iodegradat ion has been s t u d i e d i n

a c t i v a t e d sludge systems i n t h e presence o f a v a r i e t y o f c a t i o n i c species

added a t t h e same molar concent ra t ions as t h e b u i l d e r . Mercury ( H g ( I 1 ) ) i ons

and t o a l esse r ex ten t C r ( I I 1 ) and Cu( I1) i n h i b i t e d i t s b iodegradat ion. Thus

CMT a t 10-20 mg/L ( 6 x 10-'M) was t e s t e d w i t h metal s a l t s added a t 6

x 10-'M and 3 x 10-'M. A t bo th concent ra t ions mercury was comple te ly i n h i b i t o r y

whereas Cu( I1) and C r ( I I 1 ) were o n l y s l i g h t l y i n h i b i t o r y . No e f f e c t s were

observed w i t h s i m i l a r concent ra t ions o f s a l t s o f Na( I ) , C a ( I I ) , Mg( 11),

F e ( I I ) , N i ( I I ) , P b ( I I ) , Z n ( I I ) , A l ( I I 1 ) o r Cd( I1 ) (Monsanto, 1978).

S i m i l a r experiments t o t e s t t h e e f f e c t s o f meta l ions on CMOS b i o -

degradat ion were performed by adding d i f f e r e n t metal s a l t s t o a concen t ra t i on

equimolar w i t h t h a t o f CMOS (10 mg/L = 5 x 10-'M) and determin ing r a t e s o f

CMOS disappearance f rom f r e s h and es tua r i ne water. I n (Hg(1 I ) ) prevented

. . . .

degradat ion and degradat ion, was i n h i b i t e d t o d i f f e r e n t f r e s h water having 100

mg/L CaC03 water hardness, copper (Cu(L1)) and mercury degrees by C d ( I I ) ,

Z n ( I I ) , Pb( I1 ) and F e ( I I 1 ) . I n es tua r i ne waters (CaCo3 = 5,000 mg/L)

s im i I ar f i nd ings were repo r ted i n t h a t b iodegradat ion was prevented by % t h e

presence o f Hg( I1 ) and Cu(I1) ; Zn( I1 ) and Cd(I1) were a l so complete ly

i n h i b i t o r y under these cond i t i ons whereas t h e r e appeared t o be no i n h i b i t o r y

e f f e c t o f F e ( I I I ) . o r Pb( I1 ) .

When CMOS disappearance f rom r i v e r water con ta in ing added sludge was

examined f o r t h e e f f e c t s o f metal ' i ons a t iower concent rd t ions (10 m b / ~ - ' . , CMOS,

meta ls up t o 1.0 mg/L), t h e i n h i b i t o r y e f f e c t s o f t h e h ighes t concent ra t ions

o f Cu( I1) and Pb( I1 ) were l ess ev ident , Cd( I1) was w i thou t e f f e c t and Hg( I1 )

prevented biodegradat ion. Whether t he added sludge inoculum was respons ib le

f o r t h i s lower degree of i n h i b i t i o n i s impossib le t o assess because o f t h e

lower l e v e l s o f ca t i ons added i n these experiments as compared t o t h e e a r l i e r

assessments o f b iodegradat ion Lever (1977).

M ix tu res o f c i t r a t e w i t h approximately equimolar con,centrat ions o f

d i f f e r e n t meta ls were prepared t o assess t h e e f f e c t o f meta ls on c i t r a t e

b iodegradat ion a t 10 mg/L i n semi-continuous a c t i v a t e d sludge columns. Of t h e

\!aric!s met?! S. tested, ~ n ! y tri \!alent chromiu~il and mercury as Hg (NO,),

caused major a l t e r a t i o n s i n t he r a t e a t which c i t r a t e disappearea, and t h e i r

e f fec ts may have been due t o t h e t o x i c i t y o f these meta ls t o sewage organisms

a t t h e concentrat ions employed (21 mg/L CrCl3*6H20 and 25 mg/L Hg (N03)2),

r a t h e r than t o an i nhe ren t pers is tence o f the c i t r a t e - c h e l a t e s w i t h these

ions. A t lower concent ra t ions of C r ( I I I ) , f rom 0.05-5 mg/L, c i t r a t e was

degraded much more r e a d i l y . Chromium concent ra t ions t o be expected i n sewage

are no t l i k e l y t o be g rea te r than 0.5 mg/L unless s i g n i f i c a n t d ischarge f rom

l o c a l p l a t i n g p l a n t s occurs. Other metal ions t e s t e d which were w i thou t

e f f e c t on c i t r a t e b iodegradat ion were Cu, Ni, Zn, V, Mg and Na. Aluminum a t

19 mg/L aluminum c i t r a t e and i r o n as 27 mg/L f e r r i c c i t r a t e had i n h i b i t o r y

e f fec ts which were t r a n s i t o r y , and s l i g h t i n h i b i t i o n was noted w i t h lead (29

mg/L lead acetate) and cadmium (25 ppm CdC1,).

S UMMARY

C i t r a t e appears r e a d i l y biodegradable under a v a r i e t y o f environmental

c o n d i t i o n s and i t s b iodegradat ion i s apparen t l y a f f e c t e d i n p r e d i c t a b l e

f ash ion by var ious f a c t o r s . CMOS i s a l s o r e a d i l y biodegradable a l though i t

r e q u i r e s longer pe r i ods f o r t h e establ ishment o f s u i t a b l e m i c r o b i a l

popu la t ions and i s consequent ly more suscep t i b l e t o v a r i a t i o n s i n

environmental c o n d i t i o n s than i s c i t r a t e . CMT, on t h e o the r hand, i s a much

l ess r e a d i l y degradable b u i l d e r and r e q u i r e s ex tens ive per iods be fo re i t s

b iodegradat ion i s f i r m l y es tab l i shed. I t s d i t a r t r o n a t e i m p u r i t y appears t o be

degradable w i t h d i f f i c u l t y even under i d e a l c i rcumstances. Under anaerobic

cond i t i ons CMT appears no t t o degrade.

The e f f e c t s o f meta l ions on t h e degradat ion o f a l l t h ree b u i l d e r s have . .

been s tud ied bu t no i n fo rma t i on i s a v a i l a b l e t o show how va r i ous o f t h e

che la ted forms may be degradable and what environmental f a c t o r s can f a c i l i t a t e

o r r e t a r d t h e i r removal f rom the environment.

REFERENCES

Kle in , S. A. and D. Jenkins, 1972. The f a t e o f carboxymethyloxysuccinate i n

sept i c - tank and ox ida t i on pond systems. SERL Report No. 72-10. U n i v e r s i t y o f

C a l i f o r n i a , ~ e r k e 1 . e ~ .

Lever Bro thers Company, 1977. CMOS - An Empi r i ca l Isomer o f c i t r i c a c i d f o r

use as a detergent b u i l d e r - r e p o r t on i t s s a f e t y and environmental impact,

presented t o t he IJC Task Force on t he Eco log i ca l E f f e c t s o f Non-Phosphate

Detergent Bu i l de rs .

Monsanto Report I n d u s t r i a l Chemicals Company, 1978. B u i l d e r M, env i ronmenta l

and human sa fe ty , presented t o t he IJC Task Force on t h e Eco log i ca l E f f e c t s o f

Non-Phosphate Detergent Bu i lders .

M i l e s Laborator ies, Inc., P f i z e r , Inc., and P roc te r and Gamble Co. 1977. The

environmental s a f e t y of c i t r a t e . Presenta t ion t o t he IJC Task Force on t he

Eco log ica l E f f e c t s o f Non-Phosphate Detergent Bu i lders .

.., . y.'. L;*...I'. "'" ,.. &, ., , *- !.. .. '>:;:.7'7'w74,.q >*: ... + . . . :.. ,

. ..

Viccaro, J. P. and E. L. Arnbye, 1973. , Colorimetric assay for carboxymethyl-

oxysuccinate, a new detergent builder. Jour. her. Oil Chem. Soc. - 50:213-217 t '4

I

Viccaro, J. P. and E. L. hbye, 1977. Anaerobic biodegradability of carboxy-

methyl~x~succinate, a detergent bui lder. Jour. h e r . Oi 1 Chem. Soc. - 54:41-46. I

BIIOLOGICAL EFFECTS

I n cons ider ing t h e r e s u l t s o f t he experiments t o be discussed, i t i s

important t o bear i n mind t h e concent ra t ions of t h e b u i l d e r s 1 i k e l y t o be

present i n t h e environment. Under "worst case" cond i t ions , t h a t i s , assuming

no waste treatment, degradation, o r d i l u t i o n , aquat ic organisms migh t be

exposed t o 12 mg/L. Th i s cou ld occur du r i ng low temperatures, t reatment p l a n t

upsets, o r per iods o f acc l imat ion t o a new bu i l de r . O r d i n a r i l y considerable -

degradat ion and d i 1 u t i o n should occur, exposing aquat ic communities t o l ess

than 0.1 mg/L.

ACUTE TOXICITY > - . -

C i t r a t e , CMOS and CMT show a low order o f t o x i c i t y i n t e s t s us ing a

v a r i e t y o f aquat ic organisms. C i t r a t e i s t h e l e a s t t o x i c o f t h e t h r e e i n

acute exposures, a1 though d i f f e rences between t h e bu i l d e r s are smal l .

Anderson (1946) f i r s t repor ted a 48-hr EC501 of 825 mg/L f o r immobi l izat . ion

o f Daphnia magna exposed t o sodium c i t r a t e i n Lake E r i e water. Th i s i s .- . .- s i m i l a r t o e f f e c t l e v e l s f o r o the r i nve r teb ra tes and f i s h . For example t h e

96-hr LC502 f o r sodium c i t r a t e i n s o f t water was 833 mg/L f o r rainbow trout, . .

Salmo g a i r d n e r i (M i l es -- e t al . 1977); 1516 mg/L f o r b l u e g i l l , Lepomis

macrochirus (M i l es -- e t a l . 1977); 1710 f o r b l u e g i l l and 1415 mg/L f o r t h e s n a i l

Arnnicola l imosa (Schwartz and Davis, 1973). Schwartz and Davis found sodium

c i t r a t e t o be t h e second l e a s t t o x i c m a t e r i a l ( a f t e r glucoheptonic ac id ) among

a wide v a r i e t y o f p o t e n t i a l organic bu i l de rs . Tables 4 and 5 present t h e

acute t o x i c i t y o f c i t r a t e i n r e l a t i o n t o CMOS, CMT and several o ther detergent

components. Note t h a t c i t r a t e appears t o be more t o x i c t o f i s h than CMOS

(Table 5) c h i e f l y because t h e c i t r a t e was t e s t e d i n so f te r water.

'EC50 i s a concent ra t ion t h a t produces a g iven e f f e c t i n 50% of t h e t e s t organisms. I n t h i s case t h e response i s immobi 1 i z a t i o n .

2LC.50 i s a concent ra t ion l e t h a l t o 50% o f t h e t e s t organisms.

TABLE 4. TOXICITY OF DETERGENT COMPONENTS TO

*From Lever, 1977-.

M a t e r i a l

LAS

Soap

Sodium CMOS

Sodium C i t r a t e

Sodium Tr ipo lyphosphate

TABLE 5. ACLITE TOXICITY OF ORGANIC BUILDERS AND LAS TO FRESHWATER FISH

72-hr LC50, mg/L 25 ppm Hardness

19

8 5

308

1044

1842

250 ppm Hardness

10

171

11 23

1750

2624

Treatment

NaCi t r a t e

NaC i t r a te

N aCMOS

CMT

CMT

CMT

N aNTA

LAS

LAS

LAS + CMT ( 1 :2)

96-hr LC50, mq/L

833

1710

2300

309

371

1110

98

3.5

5.7

5.6

Species

Rainbow t r o u t

B l u e g i l l

Rainbow t r o u t

Rainbow t r o u t

Fathead minnow

Fathead m i nnow

Rainbow t r o u t

Fathead minnow

Fathead minnow

Fathead minnow

Hardness, mq/L

s o f t

s o f t

300

35

3 5

250

35

-

3 5

35

Reference

M i l e s e t al., 1977 -- Schwartz & Davis, 1973

Newsome & Howe, 1976

Monsanto, 1978

Monsanto, 1978

Monsanto, 1978

Macek & Sturm, 1973

Solon -- e t a1 . 1969

Monsanto, 1978

Monsanto,. 1978

There i s an a d d i t i o n a l problem i n i n t e r p r e t i n g LC50 r e s u l t s f o r r a p i d l y

degradable organics such as c i t r a t e . Test r e s u l t s vary depending on whether

nominal o r measured t o x i c a n t concentrat ions are used i n t h e LC50 ca l cu la t i on .

I n d u s t r y data show t h a t as l i t t l e as 0.2 t o 11% o f t h e nominal c i t r a t e

concent ra t ion may be recovered from cont inuous f low f i s h tanks ( rep1 acement a t

2.4 volumes/day) (M i l es -- e t al . 1977). Many o f t h e c i t r a t e bioassays were

performed i n s t a t i c aquar ia w i thout f requent water exchange. It i s unclear

f rom t h e repo r ted r e s u l t s whether degradat ion was considered. If not, t h e

ac tua l LC50 values might be lower than reported.

Sodium CMOS and CMT are somewhat more t o x i c than c i t r a t e bu t l ess t o x i c

than NTA (Tables 4 and 5). The 48-hr LC50 f o r - D. magna exposed t o sodium CMOS

was 300 mg/L i n sof t water and 2026 mg/L i n hard water (Lever, 1977). This i s

c lose t o the 96-hr LC50 f o r rainbow t rou t , which i s 2300 mg/L i n hard water.

Although no CMOS bioassay f o r f i s h i n s o f t water has been reported, i t would

be expected t o be approximately 300 mg/L as we l l . CMT f a l l s i n about t h e same

range f o r f i s h and i nve r teb ra tes (Table 5). CMT was found t o have a 24-hr

LC50 of 1012 mg/L f o r - D. magna and 899 mg/L f o r Gammarus pulex, presumably

a lso i n s o f t water (Monsanto, 1978). Note t h a t a l l CMT bioassays were

performed w i t h t h e commercial grade mater ia l . Separate t o x i c i t i e s fo r t h e

d i t a r t r o n a t e and d i g l y c o l a te i m p u r i t i e s have not been reported.

The acute t o x i c i t y l e v e l s o f a l l t h ree organic b u i l d e r s (Tables 4 and 5 )

l i e w e l l above t h e "worst case" concent ra t ion o f 12 mg/L discussed e a r l i e r . A

s a f e t y fac to r o f a t l e a s t 25 (300/12) e x i s t s even if no treatment, degradat ion

o r d i l u t i o n are assumed.

EFFECTS OF WATER c i i E P i i S ~ i ? Y . Organic b u i l d e r s are selected f o r t h e i r a b i l i t y t o form complexes w i t h

po l yva len t cat ions, i n c l u d i n g calc ium and magnesium. T o x i c i t y appears t o be a

f u n c t i o n o f the f r e e anion o r acid, r a t h e r than the meta l -bu i lder complex.

Thus Bies inger -- e t a l . (1974) found a d i r e c t c o r r e l a t i o n between t h e LC50 f o r

NTA and t h e hardness o f t he d i l u t i o n water i n t e s t s w i t h Daphnia. T o x i c i t i e s

o f c i t r a t e , CMOS and CMT also decrease w i t h g reater hardness (Tables 4 and 5).

Ac id i c , s o f t waters pose spec i a1 problems t o t h e s u r v i v a l o f aqua t i c

organisms. For example, metal t o x i c i t y o f t e n increases a t low pH. By t h e

same token, t h e p ro tona ted forms o f t h e o rgan ic b u i l d e r s have g r e a t e r t o x i c i t y

t han t h e corresponding Ca-Mg complexes. Anderson (1944) found c i t r i c a c i d t o

be more - . t ox i c t o Daphnia than sodium c i t r a t e (48-hr EC50=153 and 825 mg/L

r e s p e c t i v e l y ) . . The 96-hr LC50 f o r CMT w i t h . fa thead minnows (Pimephales

promel as) dropped from 371 t o 60 mg/L as pH was -reduced f rom 7.1 t o 6.0

(Monsanto, 1978). -The est-imated n o - e f f e c t le -ve l a t a pH o f 6.0 was 37 mg/L,

g i v i n g t h e sma l l es t marg in o f s a f e t y o f -any c o n d i t i o n s tes ted . Very 1 i k e l y

CMOS would show s i m i l a r t rends. As i n t h e case o f NTA, t h e p o t e n t i a l f o r

b i o l o g i c a l e f f e c t s w i t h c i t r a t e , CMOS, and CMT appears t o be g r e a t e s t i n a c i d

waters.

By t h e same reasoning t h e expected t o x i c i t i e s o f t h e b u i l d e r s ought t o be

lowest i n mar ine systems. Monsanto (1978) r e p o r t e d t h a t t h e 96-hr LC50 and

no -e f f ec t l e v e l s f o r CMT exceed 1000 mg/L f o r bo th t h e sheepshead minnow and

p ink shrimp. S i m i l a r i n f o r m a t i o n on c i t r a t e and CMOS i n seawater i n

unavai 1 able.

One concern cou ld be t h a t t he o rgan ic b u i l d e r s m igh t i n t e r f e r e w i t h s h e l l

f o r m a t i o n i n mo l lusks because o f ca lc ium che l a t i on . Monsanto (1978) has found

t h a t CMT produced a 96-hr EC50 o f 201 mg/L f o r she1 1 growth i n oys te rs .

S i m i l a r s t ud ies w i t h NTA, a s t r onge r che la to r , have produced no measurable

e f f e c t on mo l lusk growth i n e i t h e r f r e s h o r s a l t water.

CHRONIC TOXICITY

Chronic bioassays on aqua t i c organisms appa ren t l y have n o t been done w i t h

sodium c i t r a t e o r c i t r i c a c i d ( M i l e s -- e t a l . 1977). I n view o f i t s low acute

t o x i c i t y and r a p i d b iodegrada t ion such s t u d i e s are p robab ly unwarranted a t

t h i s t ime. There i s more j u s t i f i c a t i o n f o r ch ron i c t e s t s w i t h CMOS and CMT

because o f s lower i n i t i a l r a t e s o f degradat ion. Furthermore CMT has t h e

p o t e n t i a l f o r pe rs i s t ence i n anaerobic waters o r hydroso i l s , making i t

a v a i l a b l e t o ben th i c organisms over a longer p e r i o d o f t ime.

Chronic exposures o f Daphnia and fathead minnows t o CMT have shown no

t o x i c i t y a t expected environmental concentrat ions (Monsanto, 1978). No-ef fect

and th resho ld -e f fec t l e v e l s f o r a d u l t s u r v i v a l o f - D. magna were 100 mg/L and

150 mg/L r e s p e c t i v e l y ( t h i s i s about one-tenth t h e 24-hr LC50). Reproduction

was enhanced a t CMT concentrat ions o f 50, 100, and 150 mg/L. Such a r e s u l t i s

n o t unusual as t h e food requirements f o r Daphnia i n bioassays are no t w e l l

def ined. Add i t i ona l organic substrates i n t he t e s t medium may s t imu la te the

m i c r o f l o r a consun'ed by young daphnids. Fathead minnows were a1 so exposed t o

CMT over one generation. Growth, a d u l t s u r v i v a l and egg hatchab i l i t y were

unaf fec ted a t 100 mg/L, t h e h ighest concent ra t ion tested. Spawning a c t i v i t y

may have been reduced a t 50 and 100 mg/L b u t t he e f f e c t was not s t a t i s t i c a l l y

s i g n i f i c a n t . F r y su rv i va l , however, was s i g n i f i c a n t l y reduced a t 100 mg/L. ,

No modes o f ac t i on o r metabol ic pathways i n . f i s h have been proposed f o r t h i s

bu i l de r .

CMOS has been tes ted i n th ree chronic exposures w i t h f reshwater

inver tebra tes . Daphnia showed no ill e f f e c t s a t 50 mg/L i n a f u l l l i f e c y c l e

exposure (Lever, 1977). As w i t h CMT, j u v e n i l e p roduct ion was greater i n

treatments than i n con t ro l s . Gammarus p u l e x showed no e f f e c t s a f t e r 27 weeks

a t 100 mg/L CMOS i n s o f t water (Lever, 1977). S i m i l a r t e s t s w i t h t h e midge

Chironomus r i p a r i u s suggested t h a t a d u l t p roduct ion may dec l i ne a t 100 mg/L

( ~ e e -- e t a l . 1977). However the t rend was no t c lear . Taken as a whole, t h e

r e s u l t s o f CMT and CMOS chronic t e s t s i n d i c a t e t h a t maximum expected

concentrat ions o f these b u i l d e r s i n t he aquat ic environment (< 12 mg/L) w i l l

be harmless t o f i s h and inver tebra tes . Although a the r taxa have no t been

tes ted there i s no reason a t t h i s t ime t o expect o ther t o x i c i t y problems

a r i s i n g from these bu i lders .

BIOCONCENTRATION

Studies on b ioconcent ra t ion p o t e n t i a l i n aquat ic animals have been done

f o r bo th CMOS and CMT. Because o f t h e i r an ion ic form, bo th b u i l d e r s have low

octanol/water p a r t i t i o n c o e f f i c i e n t s ( l o g P- -3) (Lever, 1977 and Monsanto,

1978). This p a r t i t i o n p r e d i c t s a n e g l i g i b l e b ioconcent ra t ion f a c t o r by t h e

method o f Neely -- e t a l . (1974). By comparison LAS has a l o g P o f 1-2,

i n d i c a t i n g greater uptake p o t e n t i a l . The b ioconcent ra t ion o f 14C-1 abel l e d

sodium CMOS f rom water has been measured over a 24-hour p e r i o d us ing go1 d f i s h

(Newsome and Howe, 1977). No de tec tab le uptake occurred a t 1 mg/L o f NaCMOS

w h i l e t r a c e amounts were found i n t h e f i s h a t 100 mg/L. Th is uptake

represented a b ioconcent ra t ion f a c t o r of approx imate ly 0.1. Uptake and

depurat ion k i n e t i c s should, however, be f o l l o w e d over a longer p e r i o d o f t ime,

and p r i n c i p a l me tabo l i t es should be character ized.

Uptake by fa thead minnows o f 14C-label l e d carboxymethyl t a r t r o n a t e i n CMT

was fo l lowed f o r 50 days. B ioconcent ra t ion f a c t o r s (wet weight) were 10-20

f o r whole f i s h , 5-10 i n muscle, and 100-200 i n d i g e s t i v e t r a c t . Add i t i ona l

gavage experiments w i t h minnows showed more than 95% c learance f rom t h e gu t i n

96 hours. Exposure o f - D. magna t o l a b e l l e d CMT i n CMT produced a very r a p i d

i n i t i a l uptake, f o l l owed by a g radua l l y decl i n i n g body burden. Th is suggests

an i n i t i a l adsorpt ion onto the exoskeleton. I n any case, t h e t o t a l

b ioconcent ra t ion f a c t o r f o r Daphnia was 40-140, depending on t h e CMT

concentrat ion.

EFFECT ON LAS AND METAL TOXICITY

Aquat ic organisms exposed t o sewage e f f l u e n t s encounter a wide v a r i e t y o f

tox ican ts , as reviewed by Tsai (1975). Among these are t h e su r fac tan ts

i n c l u d i n g 1 i nea r a1 k y l ated sul fonates (LAS) commonly used i n detergents. To

p lace t h e d iscuss ion of b u i l d e r e f f e c t s i n b e t t e r perspect ive, da ta on LAS

t o x i c i t y a re inc luded i n Tables 4 and 5. As shown, t h e acute t o x i c i t y o f LAS

i s s i g n i f i c a n t l y g rea ter than i t i s f o r t h e organic bu i l de rs . One study us ing

a combinat ion o f LAS and CMT suggests t h a t t he b u i l d e r has l i t t l e e f f e c t on

t h e pr imary t o x i c i t y of t he s u r f a c t a n t (Table 5) .

T o x i c i t y and bioaccumul a t i o n o f meta ls may be a1 t e r e d by o rgan ic c h e l a t i n g

agents. Thus t h e t o x i c i t y o f copper i s r e l a t e d t o t h e a c t i v i t y o f t h e f r e e Cu

(11) i o n (Andrew, 1976). Ligands such as carbonate o r NTA which b i n d t o t h e

copper i o n can ac t t o reduce i t s aquat ic t o x i c i t y . Several authors have

i nves t i ga ted the e f f e c t s o f organic b u i l d e r s on metal t o x i c i t y (Table 6) .

Chynoweth e t a l . (1976) found t h a t NTA reduced Cu t o x i c i t y t o a g rea te r ex ten t

than d i d e i t h e r EDTA o r c i t r i c acid. I n f a c t c i t r i c ac id had e s s e n t i a l l y no

e f f e c t on Cu t o x i c i t y t o guppies. Nishikawa and Tabata (1959) repo r ted t h a t

TABLE 6. ACUTE TOXICITY OF METALS WITH CHELATING AGENTS.

' / (3-6) x l o e 6 M c h e l a t o r added.

2/1:1 mol a r r a t i o o f meta l /chel a tor .

Treatment

C u

C u

cu + NTA'

cu + E D T A ~ I

C u + C i t r i c ac i d l

Cu

cu + C M T ~

P b

~b + N T A ~

~b + E D T A ~

P ~ + C M T ~

96-hr LC50, mg/L, metal

0.112

0.138

0.224

0.184

0.136

0.22

0.36

29.2

>625

36

33.4

Speci es

GUPPY

GUPPY

GUPPY

GUPPY

Guppy

Fathead Minnow

Fathead minnow

Fat head minnow

Fathead m i nnow

Fathead minnow

Fat head m i nnow

Hardness, mg/L

87.5

67.2

92.8

72.5

70.0

3 5

3 5

3 5

3 5

35

35

Reference

Chynoweth -- e t a1 . 1976

Chynoweth -- e t a1 . 1976

Chynoweth -- e t a1 . 1976

Chynoweth -- e t a l . 1976

Chynoweth -- e t a l . 1976

Monsanto, 1978

Monsanto, 1978

Monsanto,' 1978

Monsanto, 1978

Monsanto, 1978

Monsanto, 1978

c i t r a t e did.'reduce. t h e t o x i c i t y o f Cu , t o go1 d f i sh . A1 though EDTA prevented

copper b ioconcen t ra t i on, c i t r a t e d i d no t (Tabata and Nishikawa, 1969).

An extensive s tudy on the i n t e r a c t i o n s o f CMT and meta ls has a l so been

repo r ted (Monsanto, 1978). Copper, cadmi um, 1 ead and z i n c were t e s t e d a1 one

and i n combinat ion w i t h LAS and CMT. The b u i l d e r was found t o reduce metal

t o x i c i t y , bu t t h e e f f e c t was s l i g h t i n comparison t o t h e s t rong de tox i f y i ng

a c t i o n o f NTA (Table 6 ) . The presence o f LAS d i d no t a l t e r t he general

t rend. Minnows exposed f o r 35 days t o 0.63 mg/L lead accumulated e s s e n t i a l l y

the,same l e v e l s w i t h o r w i t hou t CMT. I n con t ras t , NTA e f f e c t i v e l y prevented

lead uptake. CMOS has no t been tes ted w i t h metals, bu t judg ing f rom i t s weak

c h e l a t i n g a b i l i t y , t h e r e s u l t s should be s i m i l a r t o those o f CMT.

Thus no s y n e r g i s t i c e f f e c t s are p red i c ted between meta ls and c i t r a t e , CMOS

o r CMT. On t h e o the r hand, these b u i l d e r s cannot be expected t o of fer any

p r o t e c t i o n f rom meta l poisoning, as proposed f o r NTA (Sprague, 1968).

E F F E C T S ON T E R R E S T R I A L ORGANISMS

No data are ava i lab le .

SUMMARY

1. I n most waters acute t o x i c i t y l e v e l s o f a l l t h ree b u i l d e r s a l l ow a s a f e t y

f ac to r of a t l e a s t 300 over t h e h ighes t poss ib le environmental

concentrat ion. However, t h e p o t e n t i a l f o r t o x i c e f f e c t s increases sharp ly

i n ac id waters.

2. Chronic t o x i c i t y t e s t s i n d i c a t e l i t t l e p o t e n t i a l f o r harm i n most waters.

3. None o f t h e b u i l d e r s show s i g n i f i c a n t b ioconcent ra t ion . However, t h e

degradat ive pathways f o r CMOS and CMT i n aquat ic organisms have no t been

studied.

4. None o f t he b u i l d e r s seem t o p o t e n t i a t e t h e ef fects of metals, n e i t h e r do

they p r o t e c t aga ins t metal t o x i c i t y .

REFERENCES

Anderson, B.G., 1944. The t o x i c i t y thresh01 ds o f var ious substances found i n

i n d u s t r i a l wastes as determined by t h e use of Daphnia magna. Sewage Works J.

16:1156-1165. -

Anderson, B.G., L946. The t o x i c i t y th resho lds o f var ious sodium s a l t s

determined by t h e use o f Daphnia magna. Sewage Works J. - 18:82-87.

Andrew, R.W., 1976. T o x i c i t y r e l a t i o n s h i p s t o copper forms i n n a t u r a l waters,

i n : T o x i c i t y t o b i o t a of metal i ons i n n a t u r a l water, R.W. Andrew, P.V.

Hodson, and D. E. Konasewich, eds. I n t e r n a t i o n a l J o i n t Comm., pp. 127-144.

Chynoweth, D.P., J. A. Black, and K. H. Mancy, 1976. E f f e c t s o f organic

p o l l u t a n t s on copper t o x i c i t y t o f ish, i n : T o x i c i t y t o b i o t a o f meta ls i ons i n

n a t u r a l water, R.W. Andrew, P.V. Hodson, and D.E. Konasewich, Eds.

I n t e r n a t i o n a l J o i n t Comm., pp. 145-157.

Lee, C.M., J.F. Fu l l a rd , and E. Huntington, 1977. The sub le tha l e f f e c t s o f

t r i s o d i urn carboxymethyl oxysucci na te on the midge Chi ronomus r i p a r i us (Meigen) :

t h e development of a ch ron i c t o x i c i t y t e s t . Proc. 2nd Symposium on Aquat ic

Toxicol., Nov. 2-3, 1977, American Soc ie t y f o r Tes t i ng and Ma te r i a l s .

Lever Bro thers Col.npany, 1977. CMOS - An Empi r i ca l Isomer o f c i t r i c a c i d ' f o r

use as a detergent b u i l d e r - r e p o r t on i t s sa fe ty 'and environmental impact,

presented t o t h e IJC Task Force on t h e Eco log i ca l E f f e c t s o f Non-Phosphate

Detergent Bu i lders .

Macek, K.J., and R.N. Sturm, 1973. Su rv i va l and g i l l h i s t o l o g y o f f i s h

cont inuous ly exposed t o sodium n i tri l o t r i a c e t a t e (NTA) f o r 28 days. J. ~ i s h .

Res. Board Can. - 30:323-325.

Monsanto I n d u s t r i a l Chemicals Company, 1978. Bui 1 der M, environmental and . . ,

human safety , presented t o t h e IJC Task Force on t h e Eco log i ca l E f f e c t s o f ' ' '

Non-Phosphate Detergent Bui 1 ders.

Neely, W.B., D.R. Branson, and G.E. Blau, 1974. P a r t i t i o n c o e f f i c i e n t t o

measure b i oconcen t ra t i on p o t e n t i a1 of o rgan i c chemica1.s i n f i s h . Env i ron.

Sc i . . Technol,., - 8: 1113-15.

Newsome, C.S., and M.J. How, 1977. Acute f i s h t o x i c i t y and abso rp t i on t e s t s

o f exper imenta l de te rgen t b u i l d e r , t r i s o d i u m carboxymethyloxysuccinate. Proc.

2nd Symp. on Aquat i c Toxic01 . , Nov. 2-3, 1977, Anierican Soc ie t y f o r T e s t i n g

and M a t e r i a1 s.

Nishikawa, K., and K. Tabata, 1959. T o x i c i t y o f heavy meta ls t o aqua t i c

animals and f a c t o r s which decrease t h e t o x i c i t y . 111. Low t o x i c i t y o f some

heavy . meta l . complexes t o aqua t i c animal s. Tokai ku Sui san Kenkyusho. Kenkyu

Hokoku - 58:223-241. As r e p o r t e d i n ~hbm. Abst r . - 76: # 30969 j (1972).

M i l e s Labora to r ies , Inc., P f i z e r , Inc., and P roc te r and Gamble Co. 1977. The

environmental s a f e t y o f c i t r a t e . P resen ta t i on t o t h e IJC Task Force on t h e

Eco log i ca l E f f e c t s o f Non-Phosphate Detergent Bu i l de rs .

Schwartz, A.M., and A.W. Davis, 1973. The development o f phosphate- f ree heavy

du t y detergents . EPA-600/2-74-003, U. S. Environmental P r o t e c t i o n Agency,

Washington, D.C.

Solon, J.M., J.L. L incer , and J.H. N a i r 111, 1969. The e f f e c t o f sub le tha l

concen t ra t i on o f LAS on t h e acute t o x i c i t y o f va r ious i n s e c t i c i d e s t o t h e

f a thead minnow (Pimephal es promel as). Water Research - 3:767-775.

Sprague, J. B., 1968. Promis ing a n t i - p o l 1 u t a n t : che l a t i n g agent NTA p r o t e c t s

f i s h f r om copper and z inc . Nature 220:1345-6.

Tabata, K., and K. Nishikawa, 1969. T o x i c i t y o f heavy meta ls t o aqua t i c

animals and f a c t o r s which decrease t h e t o x i c i t y . V. T r i a l t o decrease t h e

t o x i c i t y o f heavy meta l ions by a d d i t i o n of complexing agents. Tokaiku Suisan

Kenkyusho Kenkyu Hokoku, 1969:255-64, as r e p o r t e d i n Chem. Abs t r . 76, 95361 z

Tsai , C., 1975. E f f e c t s o f sewage t rea tment p l a n t e f f l u e n t s on f i s h : A rev iew

o f t h e 1 i t e r a t u r e . Chesapeake Research Consortium, Inc. Pub. No. 36, pp. 229.

EUTROPHICATION EFFECTS -- -- * -- -

, . . .

SOD . I UM . ,. C I TRATE : . - . , . . . \ ..- .).

- . . . . ., . .

Sodium ci trat,e contributions to natural waters may affect a1 gae' in several

ways :

1 -- by increasing the inorganic carbon pool A .

2 -- by providing an organic substrate for heterotrophic growth 3 -- by chelation of various cations

. . .

4 -- by affecting ... - . organisms that-feed on algae. . . .. . -.

. . . . : . . . . .,

If sodium citrate were to be used in all detergents, and at a concentration of

25% of the product, its average concentration in influent wastewater would be

about 12 mg/L or 8.5 mg/L as citrate ion (4.5 x 10-'M) (Miles -- et al. 1977).

1. It is now clear that carbon-limited systems a r e rare and generally result

from extremely high inputs of nitrogen and phosphorus (Schindler 1974).

Accordingly the increased concentrations of inorganic carbon in wastewater

effluent, resulting from degradation of citrate, are unlikely to have a

significant stimulatory effect on algal growth. If anything they would

tend to favor green algae in their competition with blue-green algae as

the former are less efficient at very low concentrations of carbon dioxide

(Shapiro, 1973).

2. It is estimated that about 10% of the citrate entering treatment plants

will be found in the effluent and that in 90% of the cases, subsequent

dilution will exceed 10-fold (Miles -- et al. 1977). Thus environmental

concentrations from detergent use, neglecting further degradation, could

be in order of 0.1 mg/L (4 x 10-'M). In fact, somewhat similar

concentrations have been found in "natural" systems (Khomenko -- et al.

. 1969). There is no question that such concentrations of citrate are of

significance to aquatic bacteria as a carbon source. Indeed, the rapid

degradat ion o f c i t r a t e i n n a t u r a l waters i s evidence o f t h i s . There i s

some ques t i on rega rd ing t h e e x t e n t t o which algae can u t i l i z e c i t r a t e

h e t e r o t r o p h i c a l l y . Table 7 summarizes s e v e r a l i n v e s t i g a t i o n s i n which

at tempts were made t o grow algae w i t h c i t r a t e . It i s ev iden t t h a t i n no

case d i d c i t r a t e s t i m u l a t e s u b s t a n t i a l growth, and f o r a m a j o r i t y o f a lgae

t e s t e d i t was n o t used a t a l l . Furthermore, t h e concen t ra t i ons t h a t d i d

a l l o w h e t e r o t r o p h i c use were r a t h e r h igh -- about 10-2M. T h i s i s i n

agreement w i t h t h e f i n d i n g t h a t , i n general , a lgae do n o t have a c t i v e

uptake mechanisms f o r most o rgan ic compounds. Thus t h e concen t ra t i ons o f

c i t r a t e expected t o be added . t o r e c e i v i n g waters are u n l i k e l y t o be a

s i g n i f i c a n t . . . s t imu lus -. t o . he te ro t roph i c . . a l g a l growth. . -

. . . . . . -

3. The most l i k e l y mechanism by which c i t r a t e m igh t a f f e c t a l g a l popu la t i ons

i s through i t s c a p a b i l i t y t o c h e l a t e metals. I t has been c a l c u l a t e d

(Morel, McDuff, and Morgan, 1973; Lerman and Chi lds, 1973) t h a t a t

concen t ra t ions o f c i t r a t e o f about 10-6M, (0.2 mg/L) t h e most

impor tan t complexes would be those of copper and i r o n . The s i g n i f i c a n c e

o f t h i s i s no t so e a s i l y s t a t e d however. For example, Schelske (1962) was

ab le t o s t i m u l a t e p r imary p roduc t i on i n l a k e waters by adding che la ted

i r o n (Fe( I I I )EDTA), and Rodhe (1948) b e l i e v e d t h a t i r o n as i r o n c i t r a t e i s

more a v a i l a b l e t o algae than uncomplexed i r o n . However, Goldberg (1952)

work ing w i t h mar ine algae, and Shapi ro (1967) w i t h f reshwater algae,

demonstrated t h a t i r o n was more a v a i l a b l e t o t h e a lgae when added as

FeC13 than as i r o n c i t r a t e . Subsequent work by Shapiro (1969) tended

t o suppor t t h e conc lus ion t h a t t h e l e s s s t r o n g l y che la ted t h e more

a v a i l a b l e was t h e i ron . Th is would i n d i c a t e t h a t a d d i t i o n o f c i t r a t e t o . .

l a k e water i s u n l i k e l y t o s t i m u l a t e a l g a l growth by making i r o n more

avai 1 able.

I n a s i m i l a r fash ion, b u t w i t h oppos i t e e f f e c t , a d d i t i o n o f c i t r a t e t o a

system c o n t a i n i n g copper i s l i k e l y t o make t h e copper unava i lab le . However,

as Cu( I1 ) i s a t o x i c ion, making i t "unava i l ab le " i n e f f e c t may r e l i e v e t h e

growth o f t h e algae f rom i t s c o n s t r a i n t s . For example, ~ o r n e ' and Goldman

(1974) have shown t h a t small concen t ra t i ons o f copper a re harmful t o n i t r o g e n

f i x a t i o n by blue-green algae. I f c i t r a t e were added t o a system i n which t h i s

i n h i b i t i o n were occurr ing, n i t r o g e n f i x a t i o n and subsequent dominance by

TABLE 7. EFFECTS OF CITRATE ON ALGAL GROWTH

ALGA TESTED Tr i bonema aequale

RESULT

Sl i g h t growth

CONCENTRATION USED

?

REFERENCE

Belcher and Fogg, 1958

Belcher and M i l l e r , 1960

Belcher and M i l l e r , 1960

~ e l c h e r and M i 1 l e r , 1960

Belcher and M i l l e r , 1960

Belcher and M i l l e r , 1960

Belcher and M i l l e r , 1960

Belcher and M i l l e r , 1960

Cramer and Myers, 1952

1 Wolfe, 1954

Barker, 1935

Lewin, 1953

Bunt, 1969

Carefoot, 1968

Eny, 1950

Eny, 1951

Glooschenko and Moore, 1973

B u m i l l e r i o p s i s b r e v i s

C h l o r e l l i d i u m t e t r a b o t r y s

Tribonema aequale

Bo t r yd iops i s i n te r i edens

Monodes subterranens

P o l y d r i e l l a h e l v e t i c a

Tribonema minus

Euglena g r a c i l i s

Anabena c y l i n d r i c a

Prototheca z o p f i j

Navicula p e l l i c u l o s a

Cocconeis sp.

Pe r id in ium c inctum

C h l o r e l l a sp.

C h l o r e l l a sp.

Lake m i x t u r e

M I

M

M

M

M

M

M

?

?

?

?

?

2.5 x m

2 x M

?

Up t o 4 x M

S l i g h t growth

S l i g h t growth

S l i g h t growth

No growth

No growth

No growth

No growth

No growth

Increased r e s p i r a t i o n

No growth

No growth

Growth

Decreased growth

S l i g h t growth

S l i g h t growth, reduced r e s p i r a t i o n

No growth

blue-green algae cou ld r e s u l t -- an undesi rable occurrence. The requirement

f o r c i t r a t e by Oxyr rh is marina,a non-photosynthet ic d ino f l a g e l 1 ate, has been

shown by Droop (1959) t o depend on the che la t i ng p rope r t i es o f c i t r a t e , as the

c i t r a t e requirement could be replaced by EDTA, o r by g lyc ine , o r by a m ix tu re

of the three. As the medium i n which the a lga was grown conta ined 20 pg/L

o f CuSo4 .5 H20, t h e r o l e o f the che la tors niight have been t o render

t h e Cu(I1) i o n non-toxic.

Thus the r e s u l t s o f adding c i t r a t e t o var ious lake waters probably w i l l

depend on t h e i r contents o f heavy metals, e s p e c i a l l y meta ls such as copper and

i ron ; on the presence o f o ther che la t i ng compounds such as humic substances;

and on the a l g a l species and t h e i r p a r t i c u l a r s e n s i t i v i t i e s t o e.g. copper.

Indeed, Glooschenko and Moore (1973) found a v a r i e t y o f responses t o

experiments i n which they added sodium c i t r a t e t o Hamil ton Harbour and Lake

Ontar io water. I n general, add i t i ons o f 10 pg/L - 1 vg/L ( 4 x 10" - 4

x ~ o - ~ M ) t o Hamil ton Harbour water were somewhat s t imu l atory, and those t o

Lake Ontar io water were i n h i b i t o r y . The d i f f e r e n c e may r e s u l t from t h e

d i f f e rence between the waters, Hamilton Harbour being h i g h l y eu t roph ic w i t h a

h igh trace-element content, and Lake Ontar io being s l i g h t l y eu t roph ic w i t h a

low trace-element content. The p i c t u r e i s no t e n t i r e l y c l e a r however.

Glooschenko and Moore showed t h a t copper by i t s e l f was t o x i c t o Lake On ta r i o

algae a t 10 pg/L, bu t whereas EDTA could reverse the t o x i c i t y , c i t r a t e cou ld

no t -- even a t a concent ra t ion o f 4 x 10-6M. I n f a c t i n an experiment

w i t h Hamilton Harbour water, i t appeared as though added copper was more t o x i c

i n the presence o f c i t r a t e than i n i t s absence. I n t e r p r e t a t i o n o f the da ta i s

made more d i f f i c u l t by the f a c t t h a t c i t r a t e degradat ion must have occurred

dur ing these experiments as we l l as those described below.

I n other experiments, Payne (1973) added c i t r a t e t o 39 t e s t waters f rom 17

loca t ions , i n c l u d i n g lakes Superior and Michigan, w i t h and w i thout wastewater

ef f luent . He found no s i g n i f i c a n t add i t i ona l e f f e c t o f c i t r a t e w i t h the

e f f l u e n t , and no s i g n i f i c a n t s t i m u l a t i o n by c i t r a t e alone. Payne used the

t e s t algae Selenastrum capricornutum and M ic rocys t i s .aeruginosa i n d i v i d u a l l y ,

and so could not t e s t f o r the e f f e c t s o f c i t r a t e on compet i t ion between a lga l

species. ~ looschenko and Moore noted t h a t p r e l im inary examination o f t h e i r

samples showed no systematic changes i n species composit ion.

4. One way i n which c i t r a t e cou ld have a great e f f e c t on a lga l popu la t ions

would be i f i t had an e f f e c t on the herbivores, such as Daphnia, tha t .

graze on the phytoplankton (Shapiro, 1978, 1979). There are no data on

chronic e f f e c t s of c i t r a t e on Daphnia, bu t what e x i s t s on acute e f f e c t s

suggests 1 i tt l e i f any e f f e c t a t expected concent ra t ions (see prev ious

sec t ion) .

I n summary, it' i s l i k e l y t h a t addit io,ns o f c i t r a t e t o most waters, a t t he

concentrat ions expected, w i l l have no d i s c e r n i b l e e f f e c t on t h e i r a l g a l

populat ions, d i r e c t l y o r i n d i r e c t l y . On the o ther hand, t he re i s inc reas ing

evidence t h a t i n some types o f s i t ua t i ons , such as Hamil ton Harbour, algae are

growing under r e s t r i c t i o n by heavy metals. Such types o f s i t ua t i ons , namely

h i g h l y eu t roph ic high-metal systems, should be i nves t i ga ted more thorough ly

than t o date, and on a l a r g e r scale than h i t h e r t o .

CMOS

As i n the case of c i t r a t e , t he re are f o u r ways i n which CMOS cou ld a f f e c t

a l g a l populat ions. Assuming so le use o f CMOS as a bu i l de r , an a d d i t i o n a l

amount o f inorgan ic carbon would be added t o domestic e f f l u e n t , and l e v e l s o f

CMOS, f o l l o w i n g treatment and d i l u t i o n , cou ld be i n t he area o f 0.2 mg/L

( 1 0 - ' ~ ) (Lever, 1977). The increase i n carbon, as w i t h c i t r a t e , i s n o t

l i k e l y t o be o f consequence. No d i r e c t t e s t i n g o f t h e a b i l i t y o f t h e expected

concentrat ions t o support he tero t roph ic growth o f algae i s ava i lab le , b u t i t

appears t h a t a t l e a s t one alga, Selenastrum capricornutum, does n o t u t i l i z e

CMOS i n t h i s way even a t concentrat ions o f 30 mg/L (10-"M). That i s ,

add i t i ons o f t h i s concent ra t ion o f CMOS t o t h r e e lake waters d i d no t increase

the growth o f t he a lga over c o n t r o l s w i t h no CMOS (Ye is ley and Wil l iams,

1972). On t h e other hand, i n a s tudy o f model o x i d a t i o n ponds by K l e i n and

Jenkins (1972), du r ing pers is tence o f CMOS a t 15 mg/L ( 6 x 10-'M) t h e

a1 ga l popul a t i on was comprised predominant ly o f Cryptomonas. Fo l 1 owing t h e

commencement of degradation, t h e r e was a change t o Ch lore l l a . Because o ther

f a c t o r s such as temperature changed co inc iden ta l l y , i t i s no t c l e a r what

caused the s h i f t i n t h e algae. It might mean t h a t Cryptomonas was growing

p a r t i a l l y he te ro t roph ica l ly.

Probably more important i s t he fac,t t h a t CMOS acts as a che la to r -- a l b e i t

a weak one -1 .and t h a t some o f t h e complexes may no t be as r e a d i l y degraded.

Thus, CMOS-Cu(I1) was no t degraded a t a1 1 a f t e r 37 days (Lever, 1977). Th is

cou ld be important i n a small lake having a long res idence time. Even tua l l y

most o f t he copper could become chelated, lead ing t o s h i f t s i n t h e popu la t i on

toward blue-green a l g a l dominance, as blue-greens are more s e n s i t i v e t o copper

t o x i c i t y than are green algae and diatoms. I n add i t ion , t h e process of

n i t r ogen - f i x a t i o n - is s e n s i t i v e t o i o n i c copper (Horne and Goldman, 1974). The

f a c t t h a t ' Ye is ley and W i 11 ians (1972) found no s t i m u l a t i o n ( t o "eu t roph i c

l e v e l s " ) by CMOS of Selenastrum i n t h ree lake waters, and t h a t Schwartz and

Davis (1973) found no s t i m u l a t i o n by CMOS o f t he growth o f Anabaena,

Mic rocys t is , Selenastrum and Navicula, i s no t conclus ive. It i s t h e e f f e c t o f

CMOS i n such waters as Hamil ton Harbour t h a t needs t e s t i n g -- i.e., eu t roph i c

systems r e l a t i v e l y h igh i n metals.

F i n a l l y , CMOS a t concentrat ions up t o 50 mg/L ( 2 x 10-jM) seems no t t o .

be de t r imenta l t o Daphnia, even over per iods of 3 weeks (Lever, 1977). Thus,

an . e f f e c t 'on algae through d imin ished graz ing i s u n l i k e l y t o be evi'dent. . .

. .

: In ' :summary, a1 though ' laboratory experience w i t h CMOS suggests l i t t l e

potent i -a1 f o r eu t roph ica t ion , t h e poss ib le fo rmat ion o f long-1 ast'fng chel a tes

i n d i c a t e s t h e need f o r s tud ies under more n a t u r a l cond i t i ons where meta l

i n t e r a c t i o n s may be of g rea te r importance.

CMT

CMT i s s i m i l a r t o c i t r a t e and CMOS i n t h e way i n which i t might a f f e c t

a1 gal popul a t ions. Wastewater concentrat ions, a t maximum would be about 12

mg/L ( 5 x 10-'M) (Monsanto, 1978). The a d d i t i o n o f inorgan ic carbon t o

na tu ra l waters f rom i t s use would probably be unimportant. The expected

concent ra t ion o f t h e b u i l d e r i n r e c e i v i n g waters, assuming 90% degradat ion

dur ing treatment, and 10- fo ld d i l u t i o n , cou ld be i n t h e order of 0.1 - 0.2

mg/L (4-8 x 10-'M). Th i s concent ra t ion could be s u f f i c i e n t f o r

s t i m u l a t i o n o f he te ro t roph i c a l g a l growth bu t no d i r e c t i n fo rma t i on i s

ava i lab le . The f a c t t h a t as l i t t l e as 0.3 mg/L (10-6M) s t i r r lu la ted

Selenastrum capricornutum i n t he absence and presence of EDTA (Monsanto,

1978), would i n d i c a t e poss ib le he te ro t roph i c uptake by t h i s a l g a . As i n t h e ' "

case o f c i t r a t e , a t t h e low l e v e l s expected, copper i s l i k e l y t o be t h e meta l

che la ted predominantly, and the e f f e c t o f CMT thus i s l i k e l y t o mimic t h a t o f

c i t r a t e i n t h i s regard. The complexes formed are no t s t rong and CMT does n o t

have as g rea t a " p r o t e c t i v e " capac i t y as have .NTA and EDTA,. Th i s makes i t . .. , . , , . .

even more l i k e l y t h a t t h e s t i m u l a t i o n o f Selenastrum growth i n AAP medium

(U.S. EPA, 1971) may have r e s u l t e d f rom i t s he te ro t roph i c uptake r a t h e r than

f rom i t s r e l i e v i n g Selenastrum o f copper o r o the r metal i n h i b i t i o n . On t h e

o ther hand, add i t i ons o f up t o 16 mg/L (10e4M) o f c a r b ~ x h e t h ~ l t a r t r o n a t e

t o l a r g e (1135 L) po lye thy lene enclosures f i l l e d w i t h l ake water r e s u l t e d i n

no s i g n i f i c a n t increases i n a lga l abundance (Grisamore and Jones, 1978).

The e f f e c t o f CMT on Daphnia i s unusual. The LC i s h igh -- about

1000 mg/L ( 4 x 10-'M) -- b u t a t lower concent ra t ions o f 50-150 m g / ~ (2-6 x '

10-4M) the re seems t o be an enhancement o f rep roduc t i on (Monsanto, 1978).

Th i s may o r may no t be d i r e c t i.e., i t i s poss ib le t h a t CMT tends t o inc rease

the food resources o f t he adu l t s o r o f t he young by s t i m u l a t i n g b a c t e r i a l

growth. I n any event t h e e f f e c t i v e concent ra t ions are very f a r above those

l i k e l y i n t h e environment.

I n summary, t h e l i m i t e d evidence a v a i l a b l e suggest t h a t use o f CMT i s

u n l i k e l y t o r e s u l t i n increases i n abundance o f algae.

SUMMARY

1. Use o f CMT i s u n l i k e l y t o r e s u l t i n increased abundance o f algae i n ,

r e c e i v i n g waters.

2. Ne i the r CMOS nor c i t r a t e i s l i k e l y t o cause increased abundance i n algae

except i n s i t u a t i o n s where t h e algae are i n h i b i t e d i n heavy metals. Under

some circumstances complexat ion o f t he meta ls by t h e b u i l d e r s cou ld

r e l i e v e t h e algae f rom t h e i n h i b i t i o n . Th i s i s t r u e e s p e c i a l l y f o r CMOS.

REFERENCES ?..

Barker, H.A. 1935. The metabol ism o f t h e c o l o r l e s s a l ga Prototheca z o p f i j

Kruger. J. C e l l . Comp. Phys io l . - 7:73-93.

Belcher, J.H. and G.E. Fogg. 1958. S tud ies on t h e growth o f Xanthophyceae i n

pure c u l t u r e . 111. Tribonema aequale Paschev. Arch. f. M i k r o b i o l . - 30:517-22.

. . - . .

Belcher, J.H. and J.D.A. M i l l e r . 1960. , S tud ies on t h e growth o f Xanthophyceae. . .

. . . ,

i n pure c u l t u r e . IV. h t r i t i o n a l types among' t h e Xanthophyceae. Arch. f.. .. - . . . .

~ i k r o b i o l . . - 36:219-228.

Burt , J. 1969.' Observat ions on pho tohe te ro t rophy i n a marine .. , . diatom. J.

Carefoot, J.R. 1968. Cu l t u re and Heterot rophy o f t he f reshwater

d i n o f l a g e l l a t e Pe r i d i n i um c inctum fa . ovoplanum. J. Phycol. - 4:129-131.

Cramer, M. and J. Myers. 1952. Growth and pho tosyn the t i c c h a r a c t e r i s t i c s o f

Euglena g r a c i l i s . Arch. f. M i k r o b i o l . - 17:384-402.

Droop, M.R. 1959. Water-so lub le f a c t o r s i n t h e n u t r i t i o n o f Oxy r rh i s

marina. J. Mar. B i o l . Assoc. U.K. - 38:605-620.

Eny, D.M. 1951. Resp i ra t i on s tud ies on C h l o r e l l a . I. Growth s tud ies w i t h

a c i d in te rmed ia tes . P lan t . ,Phys io l . - 25:478-495.

Eny, D.M. 1951. Resp i ra t i on s tud ies on C h l o r e l l a . 11. I n f l u e n c e o f vapious

o rgan ic ac ids on gas exchange. P lan t . Phys io l . - 26:268-289.

Glooschenko, W.A. and J.E. Moore. 1973. The e f f e c t o f c i t r a t e on

phytop lankton i n Lake Ontar io . In, G.A. Glass, ed. "Bioassay techniques and

env i ronmenta l chemist ry" . Ann Arbor Science.

Goldberg, E.D. 1952. I r o n a s s i m i l a t i o n by marine diatoms. B i o l . B u l l . Woods

Hole - 102: 243-248.

Grisamore, S.B. and J.R. Jones. 1978. An evaluation of a phosphorus-free detergent builder in polyethylene enclosures. A report on

carboxymethyl tartronate ( CMT) to Monsanto Company. Mimeo 130 pp.

Horne', A. J. and C.R. Goldman. 1974. Suppression of nitrogen fixation by

blue-green algae in a eutrophic lake with trace additions of copper. Science

183~409-411.

Khomenko, A. N., I.A. Goncharova, A.G. Stradomskaya. 1969. Chromatographic

determinations of nonvolatile organic acids dissolved in natural waters. -

Gidrokhim. Mater. - 50:96-101.

Klein, S.A. and D. Jenkins. 1972. The fate of carboxymethyloxysuccinate in

septic-tank and oxidation pond systems. SERL Report No. 72-10. Sanitary

Engineering Research laboratory, University of California, Berkeley.

Lerman A. and C.W. Childs. 1973. Metal-organic complexes in natural waters:

control and distribution of thermodynamic, kinetic and physical factors. In,

P.C. Singer, ed. "Trace metals and metal-organic interactions in natural - -

waters.' Ann Arbor Science.

Lever Brothers Company, 1977. CMOS - An Empirical Isomer of citric acid for

use as a detergent builder - report on its safety and environmental impact,

presented to the IJC Task Force on the Ecological Effects of Non-Phosphate

Detergent Bu i 1 ders.

Lewin, J.C. 1953. Heterotrophy in diatoms. J. Gen. Microbiol . - 9:305-313.

Miles Laboratories, Inc., Pfizer, Inc., and Procter and Gamble Co. 1977.- The

environmental safety of citrate. Presentation to the IJC Task Force on the

Ecological Effects of Non-Phosphate Detergent Builders.

Monsanto Industrial Chemicals Company, 1978. Builder M, environmental and

human safety, presented to the IJC Task Force on the Ecological Effects of

on-phosphate Detergent Bui lders.

Morel, F., R.E. McDuff and J. J. Morgan. 1973. I n t e r a c t i o n s ' and chemostasis

i n aquat ic chemical systems: ' r o l e . o f p ~ , pE, s o l u b i l i t y , and complexation.

In, P.C. Singer, Ed . "Trace metals and meta l -organic i n t e r a c t i o n s i n n a t u r a l

waters". Ann Arbor Science.

Payne, A.G. 1973. Environmental t e s t i n g o f c i t r a t e : bioassays f o r algae

s t imu la t i on . Proc. 16th Conf. Great Lakes Res. : 100-115.

Rodhe, W. 1948. Environmental requirements ' o f f reshwater algae. Symb. Bot. . .

Upsal . - 10:l-149.'

Schelske, C.L. 1962. I ron, organic matter, and o ther f a c t o r s l i m i t i n g

pr imary p r o d u c t i v i t y i n a marl lake. Science - 136:45-46.

Schindler, D.W. 1974. Eut roph ica t ion and recovery i n experimental lakes:

imp l i ca t i ons f o r lake management. Science - 184:897-899.

Schwartz, A.M. and A. E. Davis. 1973. The development o f phosphate-free heavy

du ty detergents. EPA Report EPA-R2, Dec. 1973.

Shapiro, J. 1967. The a v a i l a b i l i t y o f i r o n t o algae: p r e l i m i n a r y s tudies.

In, Golterman and Clymo, Eds. "Chemical Environment i n t h e Aquat ic Hab i ta t " .

Shapiro, J. 1969. I r o n i n na tu ra l ' -wa te rs -- i t s c h a r a c t e r i s t i c s and

b i o l o g i c a l a v a i l a b i l i t y as determined w i t h t he fe r r ig ram. Verh. I n t e r n a t .

Verein. Limnol. - 17:456-466.

Shapiro, J. 1978. The need f o r more b i o l o g y i n lake r e s t o r a t i o n . I n "Lake

Restorat ion: Proceedings o f a Nat iona l Conference". EPA 440/5-79-001.

Shapiro, J. 1979. The importance .of t r o p h i c - l e v e l i n t e r a c t i o n s t o t he

abundance and species composit ion o f algae i n lakes. Presented a t SIL

Workshop on Hyper t rophic Ecosystem, vaxjo, Sweden', Sept. 1979.

U.S.EPA. 1971. A lga l assay procedure b o t t l e t e s t . Nat iona l Eut roph ica t ion

Research Program, USEPA, Corval 1 i s , Oregon.

Wetzel, R.G. 1975. Limnology. W.B. Saunders Co. 743 pp.

Wolfe, M. 1954. 'The e f f e c t o f molydenum upon t h e n i t r o g e n metabolism o f

Anabaena c y l i n d r i c a . 11. A more d e t a i l e d s tudy o f the ac t i on o f molybdenum

i n n i t r a t e ass im i l a t i on . Ann. Bot. (Lond.). - 18:309-325.

Yeisley, W.G. and I.M. Wi l l iams. 1972. 'The e f f e c t o f . carboxymethyloxysuccin i c a c i d (CMOS) on eu t roph i ca t i on as determined by t h e

a l g a l assay procedure: b o t t l e t e s t . I n t e r n a l r e p o r t #72-0026, Lever Bro thers

Research Center, Edgewater.

APPENDIX >. .

... . .

. . I * . . . . . . 6 '

,-. .

. . . . . . . .

. . . I.! . : . .

SEVENTH MEETING

OF :THE

GREAT LAKES RESEARCH ADVISORY BOARD

TASK FORCE ON

ECOLOGICAL EFFECTS ON NON-PHOSPHATE DETERGENT BUILDERS

Held a t the Ramada 0 'Hare Inn Chicago, I l l i n o i s January 11, 1978

Members

J. Shapiro A. Spacie C.R. O'Melia P. J. Chapman B. F a i r l e s s

U n i v e r s i t y o f Minnesota :Purdue U n i v e r s i t y U n i v e r s i t y o f Nor th Caro l ina U n i v e r s i t y o f Minnesota U.S. EPA, Region V

Representing Soap & Detergent Assoc.

F. Kennedy Cont inenta l O i 1 Company

I n v i tees

C. Schelske R.L. Lowe F.T. Mackenzie W. Glooschenko A.E.P. Watson P. Kilham T. Johnson

Secretary

U n i v e r s i t y o f Michigan Bowling Green State U n i v e r s i t y Northwestern U n i v e r s i t y Canada Centre f o r I n land Waters IJC Great Lakes Regional O f f i c e U n i v e r s i t y o f Michigan U n i v e r s i t y o f Minnesota

D.R. Rosenberger IJC Great Lakes Regional O f f i c e

EIGHTH MEETING

OF THE

GREAT LAKES RESEARCH ADVISORY BOARD'S

TASK FORCE ON

ECOLOGICAL EFFECTS OF NON-PHOSPHATE DETERGENT BUILDERS

Held a t t h e IJC Regional O f f i c e Windsor, .Ontar io

March 10, 1978 7. ..... . . . . . . . . . . . . Members ... - . . . . . . .

. . . . . . . . , . . :. ? . . . . . . . . . . . J. Shapiro . . ~ n - i vers i ty. o f Minnesota . : . . . . . . . . . C.R. O 'Mel ia . . . . .

. . U h i v e r s i t y : o f Nor th Ca ro l i na . : ,

R. Dick ' Cornel 1 Unj vers i t y <. . . . . . . . . P.J. Chapman

'

. U n i v e r s i t y ' of Minnesota ,. ~ .. . .. . .

K.L.E. Ka iser . . , ; : . C a n a d a c e i t r e f o r I n l a n d Waters . ' . " . " . : . . . . . . . . . .

A. Spacie . . ' .Purdue U n i v e r s i t y .. . . . . . . . . .

B. F a i r l e s s U.S. .EPA, Region V ; . . .; ; i

. . . . . . . . . . . . . . . . . . . . . . . Represent ing Soap & Detergent Assoc. . . . . . . . . . . .

- F. A. Brownr idge Proc ter & Gamble Inc. F. Kennedy Cont inenta l O i l Company

I n v i tees -. .

J.M. Weaver Lever Bro thers Company E. Mones Lever Bro thers Company M.H. Ku r t z Lever Bro thers Company V. Lambert i Lever Bro thers Company W. G l e d h i l l Monsanto Company, J. Welch U.S. EPA

Observers

F. Conrad A. E. P. Watson T.H. Dexter L. Centofani

Secre ta ry

E thy l Corporat ion Corr~pany IJC Great Lakes Regional O f f i c e Hooker Chemical s Monsanto

D.R. Rosenberger IJC Regional Of f ice

NINTH MEETING

OF THE

GREAT LAKES RESEARCH ADVISORY BOARD'S

E,COLOGICAL EFFECTS OF NON-PHOSPHATE DETERGENT BUILDERS

Held a t t h e Ramada OIHare I n n Chicago, I 1 1 i n o i s

A p r i l 27, 1978

Members

J. Shapiro U n i v e r s i t y o f Minnesota P.J. Chapman U n i v e r s i t y of Minnesota R. D ick Co rne l l U n i v e r s i t y A. Spacie Purdue U n i v e r s i t y C.R. O 'Me l i a U n i v e r s i t y o f No r th C a r o l i n a K.L. E. Ka iser Canada Centre f o r I n l a n d Waters B. F a i r l e s s U.S. EPA, Region V

Represent ing Soap & Detergent Assoc.

F. Kennedy Cont inen ta l O i l Company F. A. Brownridge P roc te r & Gamble Inc.

Sec re ta r y

D.R. Rosenberger IJC Great Lakes Regional Of f ice

TENTH MEETING

O F THE . .

, . .

GRE'AT LAKES RESEARCH ADVISORY BOARD 'S

TASK FORCE ON . . . . . . . . . . . ' . . < . . . . , . . . . . . . . . ,

ECOLOGICAL EFFECTS OF NON-PHOSPHATE DETERGENT BUILDERS . . . . . . > . I . ' .

- . . -

He1 d., ,at the- ,Ramad.a 1nn- Sharonvi 1 le,; Ohio

September 26-28, 1978 . .

. . . . . -. . . . . . .

Members ., . , - . ,

, . . , ? . . . . . j .. i . I

. . . . . : . . . . . . . .

, , . . . J. Shapiro ' ~ n i ~ v e r s i t y o f Minnesota ! . . , . < . . . C.R. O'Mel ia ' U n i v e r s i t y o f Nor th .Carol i :na . . . . . . . . , .

. . . . . . . A. Spacie Purdue Uni.vers i ty . : . . ..- < . - . . . . . K.L.E. Ka iser Canada Centre f o r I n l a n d Waters . ..

P.J. Chapman ~ n i v e r s i ty o f Minnesota . - . . . . . . . . . . . . . . . . . . R. D ick Cornel 1 U n i v e r s i t y . : - . . . ,. . . . . . . . . . . . I .

. . .

B. F a i r l e s s U.S. EPA, Region V . , . . . . . . . . . . . . - .

. . Representing Soap & ~ e t e r ~ e n t ' : A s s o c . : ' , . ' ; - . . , . . .., . . . . , ... . z

F. Kennedy F. A. Brownridge

I n v i tees

R.K. Lehne W.D. Hopping R.N. Sturm K. Sav i tsky L.W. Beck A.M. Maki

Observers

Cont inenta l O i l Company Proc ter & Gamble Inc.

G. Wei denhammer A.G. Payne M.E. Tuve l l H. W. Rees W.D. Hopping B.H. Wiers T.E. Cook R.C. Bunch J.M. Weaver L.W.' Beck

Secretary

Church & Dwight Proc ter & Gamble Company Proc ter & Gamble Company Proc ter & Gamble Company Proc ter & Gamble 'Company Proc ter & Gamble Company

Union Carbide Corpora t ion Proc ter & Gamble Company E thy l Corporat ion E t h y l Corporat ion Proc ter & Gamble Proc ter & Gamble Company Proc ter & Gamble Company U. S. EPA, Ohio Lever Brothers Proc ter & Gamble Company

D. R. Rosenberger IJC Great Lakes Regional O f f i c e

ELEVENTH MEETING

OF THE

GREAT LAKES SCIENCE ADVISORY BOARD'S

TASK FORCE ON

ECOLOGICAL EFFECTS OF NOIV-PHOSPHATE DETERGENT BUILDERS . . . . ,

. .

Held a t the Ramada O'Hare Inn Chicago, I l l i n o i s December 1, 1978

Members

C.R. O'Mel ia U n i v e r s i t y o f Nor th Caro l ina P.J. Chapman U n i v e r s i t y o f Minnesota A. Spacie Purdue U n i v e r s i t y G.H. Adams, Jr. f o r

B. F a i r l e s s U.S. EPA, Region V R. Dick Corne l l U n i v e r s i t y

Representing Soap & Detergent- Assoc.

F.A. Brownridge F. Kennedy

Proc ter & Garr~ble Company Cont inenta l O i l Company

Secretary

D. R. Rosenberger IJC Great Lakes Regional Of f i ce

OF THE

GREAT LAKES SCIENCE ADVISORY BOARD'S . .

TASK FORCE ON THE

. .

Hei b a t t h e U . S . EPA O f f i c e Washington, .D.C. March 6-7, 1979

. . . . . . . . . . . . . . . . . Members

. . . . . , . . .

J. Shapiro . U n i v e r s i t y o f Minnesota ? . . :

. . . . . P.J. Chapman U n i v e r s i t y o f Minnesota . , . . . ,

C.R. OIMelia : - - , U n i v e r s i t y o f Nor th Carol i n a . .

K. L. E. Ka iser Canada Centre f o r I h l a n d Waters R. Dick Cornel 1 U n i v e r s i t y . . . . . . . - . . . . . . .

. . . . Represent ing Soap & Detergent Assoc. . . ... . . -. . .. , .

F. Kennedy Cont inent a1 O i 1 Company F.A. Brownridge Proc ter & Gamble Company

. . . . . . . - . . . . . . . .

I n v i t e e . - . . , .. , . . . .

S. F reder icks U.S. EPA

Observers

J. Bar r

Secretary

D.R. Rosenberger

U.S. EPA

IJC Great Lakes Regional O f f i c e

THIRTEENTH MEETING

OF THE

GREAT LAKES SCIENCE ADVISORY BOARD ' S

TASK FORCE ON

ECOLOGICAL EFFECTS OF. NON-PHOSPHATE DETERGENT BUILDERS

Held a t t he Ramada OIHare Inn Chicago, I l l i n o i s

A p r i l 24, 1979

Members

J. Shapiro U n i v e r s i t y o f Minnesota P. J. Chapman U n i v e r s i t y o f Minnesota K.L.E. Ka iser - Canada Centre f o r I n l and Waters A. Spacie Purdue U n i v e r s i t y

Representing Soap & Detergent Assoc.

F. Kennedy F.A. Brownridge

Cont inenta l O i l Company - P roc te r & Gamble Company

Secretary

D. R. Rosen berger IJC Great Lakes Regional O f f i c e

TERMS OF REFERENCE

INTERNATIONAL JOINT COMMISSION - GREAT LAKES SCIENCE ADVISORY BOARD

TASK FORCE ON ECOLOGICAL EFFECTS OF NON-PHOSPHATE DETERGENT BUILDERS

E u t r o p h i c a t i o n o f t h e Great Lakes remains one o f t h e se r i ous problems t o which t he Great Lakes Water Q u a l i t y Agreement i s addressed. Phosphorus has been acknowledged t o be t h e n u t r i e n t l i m i t i n g a l g a l growth and, f o r t h i s reason, programs t o c o n t r o l t h e i n p u t o f phosphorus a re presented i n Annex 2 o f t h e Agreement.

A s i g n i f i c a n t p r o p o r t i o n o f t h e phosphorus e n t e r i n g t h e Great Lakes i s due' t o phosphates d ischarged f rom mun ic ipa l sewage t rea tment p l an t s . Therefore; t h e Agreement s p e c i f i e s t h a t waste t rea tment f a c i l i t i e s s h a l l be cons t ruc ted and operated t o remove phosphorus f r om mun ic ipa l sewage.

The Annual Report o f t h e Water Qua1 i t y Board and t h e F i n a l Repor t o f t h e Upper Lakes Reference Group bo th presented a t t h e J u l y 1976 meet ing o f t h e I n t e r n a t i o n a l J o i n t Commission addressed t h e ques t ions o f phosphorus d ischarge f rom mun ic ipa l wastewater t rea tment p l an t s . As a s i g n i f i c a n t p r o p o r t i o n o f t h e phosphorus i n sewage a r i s e s f r om de te rgen t usage bo th r e p o r t s recommend l i m i t a t i o n s on t h e phosphorus con ten t o f detergents .

As such a ban o r l i m i t a t i o n on phosphates i n de te rgen ts w i l l r e q u i r e a1 t e r n a t i v e b u i l d e r compounds and/or l e v e l s t o be u t i 1 ized, r e l e v a n t e c o l o g i c a l i n f o r m a t i o n rega rd ing t h e e f f e c t s o f such m a t e r i a1 s must be gathered and i n t e r p r e t e d t o pe rm i t t h e Commission t o eva lua te t h e p o t e n t i a l consequences o f such detergent r e f o r m u l a t i o n based upon t h e bes t a v a i l a b l e s c i e n t i f i c i n f o rma t i on . To p rov ide t h i s i n f o r m a t i o n t h e Science Adv i so ry Board should rev iew t h e i n f o r m a t i o n on e c o l o g i c a l e f f e c t s o f non-phosphate de te rgen t b u i l d e r s i n p resen t use.

To p rov ide t h i s i n f o r m a t i o n t h e Task Force w i l l :

1. Review and s u m a r i z e t h e research f i n d i r l g s on de te rgen t b u i l d e r a l t e r n a t i v e s t o phosphate.

2. I d e n t i f y areas o f research i n which t h e r e a re gaps i n our knowledge r e l a t i v e t o t h e e f f e c t s o f p o t e n t i a l a l t e r n a t e b u i l d e r m a t e r i a l s .

3. Report t o t h e Science Adv isory Board on t h e adequacy o f s t ud ies p e r t a i n i n g t o these m a t e r i a l s and i d e n t i f y bo th these m a t e r i a1 s which, based on p resen t in fo rmat ion , a re judged t o be e c o l o g i c a l l y acceptable and those which a re not .

The Task Force w i 11 consider:

1. Expected discharge l e v e l s and t h e ex ten t t o which ambient concentrat ions w i 11 be increased.

2. E f f e c t s on t h e sewage t reatment process.

3. B iodegradat ion and physicochemical t rans format ion .

4. Expected o r known degradat ion products w i t h spec ia l re fe rence t o t h e more s t a b l e ones.

5. T o x i c i t y t o b io ta .

6. Che la t ion o f t r a c e metals and m o b i l i z a t i o n o f metals.

When used i n apprec iable quan t i t i es , a l l types o f detergent b u i l d e r s can p o t e n t i a l l y e f f e c t t h e ecosystem o f t he Great Lakes. Upon complet ion o f i t s rev iew o f t h e eco log i ca l e f f e c t s o f non-phosphate detergent bu i l de rs , t h e Task Force w i l l compare the types and ex ten t o f impacts expected w i t h t h e use o f non-phosphate bu i 1 ders t o t h a t o f phosphorus.

MEMBERSHIP

Task Force members should i nc lude an aquat ic b i o l o g i s t , an aquat ic t o x i c o l o g i s t , an environmental chemist, a modeler, and a waste t reatment engineer. To prov ide necessary l i a i s o n w i t h t h e i n d u s t r y a non-vot ing member should represent t h e U.S. and t h e Canadian Soap and Detergent Associat ions. Persons se lec ted t o serve on t h e Task Force should be knowledgeable rega rd ing bo th t h e open l i t e r a t u r e and t h e r e p o r t l i t e r a t u r e . To p rov ide t h e most adequate eva lua t i on and repo r t , s c i e n t i f i c i n fo rma t i on i n p u t shoul d be s o l i c i t e d f rom both government and i ndus t r y .

TASK FORCE MEMBERS LIAISON MEMBERS

Professor Joseph Shapiro (Chairmnan) L imnologica l Research Center U n i v e r s i t y o f Minnesota Minneapolis, Minnesota

D r . Peter J. Chapman Department o f B iochemist ry U n i v e r s i t y o f Minnesota St. Paul, Minnesota

D r . R ichard Dick J.P. R i p l e y Pro f . o f Engineering Corne l l U n i v e r s i t y I thaca, New York

D r . Charles R. OIMel ia Professor o f Environmental Sciences

and Eqgineering U n i v e r s i t y of Nor th Ca ro l i na Chapel H i 11, Nor th Carol i n a

D r . Ann Spacie Department o f Fo res t r y and

Natura l Resources Purdue U n i v e r s i t y West Lafayette, Ind iana

M r . David R. Rosenberger (Secre ta ry ) I n t e r n a t i o n a l J o i n t Commission Great Lakes Regional O f f i c e Windsor, On ta r i o

Represent inq Soap and Deterqent . ~ s s o c i a t i o n o f Canada

-

M r . F.A. Brownridge Manager Pro fess iona l and Regulatory Serv ices Proc ter and Gamble Inc. Hamilton, On ta r i o

Represent ing Soap and Detergent Associat ion, New York

D r . F l y n t Kennedy . Manager, Chemical Research

Research and Development Department Conoco Inc. Ponca City, Ok 1 ahoma

Represent ing Environment Canada D r . K.L.E. Ka iser Environmental Contaminants D i v i s i o n Canada Centre f o r I n l a n d Waters Bur l ing ton , On ta r i o

Represent ing U.S. Environmental P r o t e c t i o n Agency

Ms. Jus t i ne Welch Hazard Assessment Group O f f i c e o f Toxic Substances U. S. Environmental P r o t e c t i o n Agency Washington, D.C.

Represent ing U.S. EPA, Region V D r . W i l l i a m F a i r l e s s Centra l Regional Labora tory U.S. Environmental P r o t e c t i o n Agency Chicago, I l l i n o i s

International Joint Commission Great Lakes Regional Off ice

100 Ouel lette Avenue Eighth Floor

indsor, Ontario N9A 6T3