sodium isopropyl xanthate

8/10/2019 sodium isopropyl xanthate

1/22

.

UTE TOXI ITY

OF

SODIUM ISOPROPYLX NTH TE TO THE

F THE D

MINNOW

Pimepha1es prome1as ND

Daphnia

pu1icaria

September

197

This document is made available electronically by the Minnesota Legislative Refas part of an ongoing digital archiving project. http://www.leg.state.mn.us/lrl/lrl.a


2/22

UTE TOXI ITY OF

S O I ~

ISOPROPYLX NTll TE

TO

THE

F THE D

MINNOW Pimephales

promelas N

Daphnia pulicaria

Submitted in fulf i l lment

of

Contract 69 9 for

the Minnesota

Pollution

Control Agency

Kevin Alto

University of M

September, 1978


3/22

ge

STR CT


4/22

Page

INTRODUCTION TO mE REGION L COPPER NICKEL STUDY

The

Regional Copper-Nickel Environmental

Impact S tudy

is

a

compr

examination of

the potent ia l cumulative environmental socia l an

impacts

of copper-nickel

mineral development

in

northeastern Min

This

study

is

being

conducted

for

the Minnesota Legislature and s

Rxecutive Branch agencies under the direct ion of the Minnesota

mental

Quality Board ~ [ E Q B

and

with the funding review

and

co

of the

Legislative

Commission on Minnesota Resources.

A reg:i.on along th e

surface

contact

of

th e Duluth Complex in

St.

L

Lake

counties

i n nor thea st er n

Minnesota

contains

a

major domes ti c

of copper-nickel sulf ide

mineralization. This

region

has been

ex

several

mineral resource

development

companies

for

more

than twe

and recently two firms ~ ~

and

Internat ional

Nickel

Company, ha

considered

commercial

operations. These

exploration

and

mine

pla

act iv i t ies indicate the potent ial est ab li shmen t o f

a new

mining

a

cessing

industry in

Minnesota. In addit ion

these act iv i t ies ind

need for

a comprehensive

environmental

socia l and economic ana

the

s ta te

in

order

to consider the

cumulative regional imp li ca ti o

new industry and to provide adequate information fo r future sta te

review

and

development. In

January 1976

the MEQB organized and

the

Regional

Copper-Nickel Study.

The major

objectives

of

the

Regional Copper-Nickel Study are: 1

characterize

the region

in

i t s

pre-capper-nickel development sta t

ident i fy and

describe t he p robabl e t echnolog ie s which

may

be used

the

mineral

resource

and to

convert into

salable

commodities;

identify

and

assess

the

impacts

of

primary

copper-nickel

developm

secondary regional growth; 4

to

conceptual ize al ternat ive degree

regional copper-nickel development; and 5 to

assess

the cumulati

enVironnlental social and economic impacts of such hypothetical

ments. The Regional Study

i s

a sc ient i f ic

information

gathering

analysis

effor t and

wil l not

present subject ive socia l

judgements

whether \. here Hhen

or

hOH copper-nickel development should or

not

proceed. In

addit ion th e Study

\ . il l not

make or propose sta

pertaining

to copper-nickel

development.

The Minnesota Environmental Quality Board i s a sta te agency r es po

the

implementation of

the

ULnnesota

Environmental

Policy

Act

and

cooperation betHeen sta te

agencies

on environmental

matters.

The

Copper-Nickel Study

is an ad hoc

ef for t

of the MEQB and

future

re

and

s i te

specif ic environmental impact studies

wil l

most l ikely b


5/22

ge

T LE OF CONTENTS

R ~

STR CT I

INTRODUCTION TO THE REGION L

COPPER NICKEL

STUDY

T LE OF

CONTENTS

LIST OF

T LES iv

LIST

OF FIGURES

v

INTRODUCTION

} ~ T E R I L S ND

METHODS

3

RESULTS

8

DISCUSSION

LITER TURE CITED 6


6/22

Page iv

LIST OF T BLES

Table 1.

N i n e t y s i x

hour LCsO

v alu es f o r

sodium

i so p r o p y l x a n t h

Table

2.

Chemical charac te r i s t ics of

di lut ion

w ater

Table 3. T es t c on dit io ns fo r

fathead

minnow

b io as s ay s

Table

4. T es t c on dit io ns fo r p h n i ~ b i o a s s a y s

Table

5.

D e g r a d a t i o n

T es t

Table

6. Spearman Karber e st i m a t e s

o f

LCsO s

mg

sodium

i sopropyl /xantha te / l i t e r

Table

7. Spearman Karber e st i m a t e s

o f the

LCsO s

in b i o a s s a y s

u s in g aged

st o c k

s o l u t i o n s

Table 8 . A bs orb an ce o f Sodium

I so p r o p y l x a n t h a t e

solu t ions over

96 hours

Table

9. Xanthate c o n c e n t r a t i o n s o f

s o l u t i o n s

aged

under

d i f fe ren t

c o n d i t i o n s

Table

lO . C o p p er x an th ate

m i x t u r e b io as s ay


7/22

ACUTE

TOXICITY

OF SODIUM ISOPROPYLXANTHATE

TO

THE

FATHEAD

MINNOW Pimephales promelas

AND Daphnia pulicaria

INTRODUCTION

Xanthates

are

dithiocarbonates which

are used

in

the f lo ta t ion

pr

for most

sulf ide

min era ls , th e metal l ic elements such

as

copper,

lead, zinc, s i lver

and

gold, and a number of oxidized m inerals of

and copper. Flotat ion i s a physiochemical

method

of

concentratin

ground

ores.

The

process involves

chemical

tre atmen t o f

an

ore

p

create conditions favorable for the

a tta chment o f certain mineral

to a ir bubbles. The a ir bubbles carry the selected minerals to t

face of the pulp and form a s tabil ized f roth

which i s

skimmed off

other

minerals

remain submerged in the pulp. Xanthates

f i t

into

by funct ioning a s collectors Collectors aid in

t he a tt achmen t

par t ic le

to

an a ir bubble. Sodium isopropylxanthate i s one of th

monly

used

xanthates Dow

Chemical Co., 1976 .

Since

xanthates

may be discharged from t a i l ing ponds into nearby

toxic i ty information is important. Acute toxic i ty values found

i

are summarized

in

Table 1.


8/22

Page 2

trout in

water of 348 ppm hardness found

that

the 96-hr LCSO of

xanthate was 18-20 mg/1.

TABLE Ninety-six

hour

LC5 values for sodium isopropy1x

96-hr LC5

Species

mg/1

Refe

Daphnia

magna

0.1-1.0

Hawl

Natrapis atherinaides 0.01-0.1

Hawl

Pimepha1es

prame1as

0.32-5.6

Hawl

Catfish

>10

Hard

Snails

10-100

Hard

Tadpoles 10-100

Hard

a ma gairdneri

100-180

Webb

Chemical degradation

i s

also of concern in xanthate toxici ty.

X

tions are not stable

in

acid medium Dyer and Phifer ,

1969 .

Ho

a tu re r epor ts indicate that alkal ine

solutions

of xanthate are so

Harris

1970 ,

quoting o th er p apers, re por te d that , in one study

si t ion of a xanthate

solution

took place

over

an e igh t-day period

but only 25 a t pH

10.8.

Other studies showed

that

decompositio

solutions

was

minimal a t pH

10-13.

Fuerstenau

1974 ,

working w

o

solutions

of

ethy1xanthate

and amy1xanthate a t 12 C and pH 8.6,

s ignif icant

decomposi tion . Tro fimovich , e t a1.

1976

reported


9/22

Page

3

The

present

study was

undertaken

to dete rm in e the acute toxici ty

isopropy1xanthate

and

to determine whether

the toxicity

of

sodium

xanthate changes with time.

MATERIALS

N

~ i l l T H O S

Acute

Toxicity

- Fathead minnows

and Daphnia pul ica r ia .

Acute

toxic i ty of sodium isopropy1xanthate

to

the

fathead

minnow

by

48-hr

and 96-hr b ioassays

in

s ta t ic solutions. Dilution water

tes ts came

from

a well a t the Department of Entomology, Fisheries

Universi ty of Minnesota, St.

Paul,

and

from

the South Kawishiwi

R

Minnesota.

Dilution

water

for

the 96-hr

tes ts

was

taken

from Lak

the U.S. EPA Environmental Research Laboratory, Dulu th , Minneso ta

character is t ics of

th e

waters are

given in Table

2.

The fish

used in

the 48-hr tes ts

were f o u r w e e k ~ o l d fathead minno

prome1as,

reared

at

th e

St.

Paul

laboratory.

The f ish

used

in

th

were

eight-week-01d

fathead minnows reared a t the

Duluth

laborato

were

placed in testing chambers 24 hours before

the addition of

Ten f ish were placed in

each

chamber. The

fish

were

not fed duri

ments.

Twen ty - li te r g la s s

t es t

chambers

50 cm

x 25 cm x 16

cm

high

we

St. Paul laboratory and

6 1i ter

cylindrical polyethylene chambe


10/22

Item

TABLE

Chemical characterist ics of

dilution water

Conc en tra t ion mg / 1

Laboratory

South

Kawishiwi

Well River

Date sampled

L ?L@?

Total Hardn ess a s

CaC

3

Calcium

as

CaC

3

Magnesium

as

CaC

3

Iron

Chloride

Sulfate

Fluoride

Total

Phosphates

220

140

76

2


11/22


12/22

age

Th e following

day,

f i v e young d aph nids , 1 2- 12 hours ol d,

were

each

tes t

chamber. The

temperature

in each chamber was recorde

The pH and t oxi cant l e v e l in each

chamber,

an d the lk l ini ty

conductance in

c o n t r o l s

w er e m ea su re d

t

th e

end

of each exper

c on ditio ns a re summarized in Table 4.

TABLE

4.

T es t c on d it io n s

for

Daphnia bioassays

Fa c tor Hean

Range

Temperature

18.1

17.5-18.5

pH

7.8

7. 6-8. 0

T ot al

A l k a l i n i t y

39

Hardness

46

S p e c i f i c

Conductance

9

The trimmed

Spearman-Karber

method

described by

Hamilton,

e t

used

to estimate LC50 s.

pegradat i on Tests

Two experiments were ru n with

s o l u t i o n s

of sodium i so p ro p y lx a n

determine

th e

degree

of

xa ntha te

breakdown over tim e. Two bioa

also ru n

to

determine whether t o x i c i t y

changes as

a

xanthate

s


13/22

Page 7

of lO mg/l and

50 mg/l. Another se t of solut ions was

prepared

ionized water t a

xantha te concentra tion

of 5g/ l .

In the second ser ies of exper iment s, six test

chambers

were se

determine the

effects of pR

aeration and

xanthate concentrat i

breakdown r te of xanthates. Lake Superior water was

used

as

t

water. The

design

is summarized

in Table

5. Absorbance readin

t

the

beginning,

f te r 24

hr,

and

fter

96

hr.

TABLE

5.

Degradation

Test

Chamber

Xanthate Cone

Factor

mg/l)

1

Aerated

with

irs

tone

2

75

Rel added

,.

3 75

NaOR

added

4

5

150

6

0

Two series

of 48-hr

s t t i bioassays were

ru n

to

determine

whet

toxi,city

changes with time. These bioassays

were

conducted in


14/22

Page 8

The third used 48 hr

old

stock

and

th e

fourth used

9 day old

Well

water

was used for

the dilut ion water .

Daphnia pulic r i

were

used

in the sec and series of 48 hr s t

assays.

Lake Superior

water was used as the

dilut ion

water .

solution of

xanthate

which had been allowed to stand uncovere

was used. The stock was

mixed

t a nominal concentration of

After

72 hours the stock

solution

was cloudy and the analyzed

256

mg

xanthate/I .

Hixture Bioassay Daphnia

The t e s t solutions

were

prepared

with

an

attem pt to keep

the

r tio

constant . The

low

treatment

level contained about

37

value of each toxicant . The

high

treatment level

contained a

the LC5

value of

each treatment. f the toxic interact ion

o


15/22

Page 9

Results

of the

degradation

experiments

are

given in

Tables

8 an

Results

of the

copper-xanthate mixture bioassay are given in T

LC5 was

calculated

by exp re ss in g t he

level

of toxicant in

each

the

sum of

the f ract ions of xanthate and copper LC50 s present

Thus an LC5 of l:toxic uni t would indicate a st r ic t ly

addit i

would indicate more than

addit ive

effects and >1, less

than

effects


16/22

Page

10

TABLE 6. Spearman-Karber estimates of LCSO s

mg sodium

isopropyl/xanthate/l i ter

Fathead JIlinnow Tests

Water Duration LC50 95

confid

Well

water

48

hr

31.11 26.24, 36

River water 48 hr

32.52

27.32, 38

River

water

48 hr 35.65

29.63,

42

River water

48

hr

46.45

41. 77

50

L.Superior

96

hr

47.079 41. 24, 53

L.

Superior

96

hr

39.33

25.52,

60

L.

Superior

96

hr

31.34 24.43, 40

L.

Superior

96

hr

37.98 31. 67, 45

L.

Superior

96

hr

28.35

26.55,

30

L.

Superior

96

hr 39.177

33.95,

45

Weighted mean

of

96 hr

LC50 37.72

Daphnia

Tests

L.

Superior

48

hr

21.

74

20,00,

23

L.

Superior 48

hr

21. 72 19.49,

24

L.

Superior

48

hr

22;

76

19.46,

26

Weighted mean

of

96 hr

LC50

21.

97


17/22

Page 11

TABLE 7. Spearman-Karber estimates of

the

LC50 s

in bioassays

using aged

stock solutions

Fathead minnow t t

Age

of Stock

Solution

Fresh

1-day-01d

2--day-01d

9-day-01d

Daphnia Test

48 hr

LC5

mg/1

95

Con

24.86

2 1. 7 4

39.81

35.25

25.14

20.00

30.49

27.33

72-hour-01d

13.42

10.62-1


18/22

Page

T LE

bsorbance of Sodium

sopropyl-

xanthate

solutions

over

96

hours


19/22

Page 13

TABLE 9. Xanthate concentrations of solutions

aged

under

different conditions

Xanthate Concentration (m

Chamber

Factor

a

hrs

f

hrs

96

aerat ed 81. 6 82.5

85

2

acidic 0.0

0.0

0

3

basic

80.4 80.0 79

80.0

79.9

79

5

doubled concentration

157.1

155.7

158

6

0.0

0.0 0

TABLE

10 .

Copper-xanthate mixture bioassay.

[eu]

(jlg l)

Xanthate

(jlg l)

Chamber

fraction

of LC5

fraction

of

3.40

.37

5.82

.26

2 3.85

.41

8.05

.37

3

5.25

.57

10.87

.49

4

5.95

.64

19.82

.90

5 7.55

.81

19.01 .87


20/22

DISCUSSION

ACuLe Tests

The LC5 v l ~ s reported

in the l i te ra ture a re gener all y

low

LC values found in the present study.

The

course of

toxic

action

of

sodium

isopropylxanthate

appea

inconsistent. Mortali ty of

fathead minnows

would

occur eith

f i r s t

24-hr period or

af ter

the

second

day.

In some of th

t re atment s, t he solution

would turn

cloudy overnight. No f i

in a cloudy solution. This cloudiness appeared with no app

Fo r

example, in

one case

the

second

highest

treatment level

in

24 hours

and

the highest treatment level

turned

cloudy

af

f

the

high treatment did not turn cloudy the

fish

would s t i

although at a slower ra te

Toxicity

was indicated by

er ra t i

loss

of

orientat ion,

followed

by

lethargy

and

gaspingll

on

t

the

tank,

and

f inally death. The type of dilut ion

water

did

to be a

factor in the toxic i ty of

xanthates :

Daphnids

would

occasionally

get caught

in the

surface

film o

solut ion,

but

th is

was

never observed

in

a

control

chamber,

became caught i t usually would

survive even i f the

other

dap

Degradation Tests


21/22

Page 15

which led

to

rapid xanthate breakdown. Cloudiness was obse

the stream

from

the

pipet te

which

was

used

to in tro du ce the

solution. This cloudiness disappeared af te r a few seconds.

solutions turned cloudy

during

the

experiment.

In the bioassays conducted

with

fathead minnows

using

an ag

t ion,

toxici ty appeared

to

be lower af te r the

f i r s t

day, bu

no differences from

the

i n i t i a l toxici ty af te r 2 and 9 days

cloudy solutions were

observed.

The 48-hour LC5 value for the

Daphnia

bioassay using 72-ho

solution was

6

of the weighted mean LC5

value found

usin

The stock solution used in this

t es t

was cloudy. The lower

that

toxici ty i nc re as ed with

degradation.

Copper-Xanthate Ivlixture Bioassay

The survival of daphnids in higher

treatments

in

the

mixtur

Table

10) was the resul t

of

these daphnids becoming

trappe

surface f i lm. One organism

in

chamber 4 was trapped in

the

as were a l l

the

survivors observed in chamber 5. f these

counted as

mortal i t ies

the

Spearman-Karber estimate

of

the

is 1. 22 t ox ic u ni ts with

95

confidence l imits of

1.13-1.

Page

16


22/22

Literature

Cited

American Water

Works Association and

Water

Pollution Control Federation.

Dmv Chemical

Co

1976. Flotation Fundamentals and Mining Chemicals.

78 pp .

Dyer

J.

a nd L.H. Phifer. 1969. Cellulose Xanthic Acid. T Studies of

Hodel Systems. Macromolecules 2;111=117.

Fuerstenau

M.C. 1974. The Toxicity

of

Se lec ted Su lfhydra l

Collectors

to

Rainbow

Trout.

Bureau

of Mines

Open

Fi le

Report

11-75.

28 pp.

Hamilton

M.A. R.C.

Russo

and R.V.

Thurston.

1977. Trimmed Spearman

Karber Method fo r Es timating ~ l e i n Lethal Concentrations

in

Toxicity

Bioas sa ys . Env ir on .

Sci.

Technol.

11:714-719.

Harris G.H. 1970. Xanthates. Pages 419-429 in Encyclopedia of Chemical

Technology Vol.

22 2nd ed . John Wiley and Sons Inc.

Hawley J.R. 1972. The Use

Characterist ics

and Tox ic it y o f Mine-mill

Reagents in th e Provi nc e o f Onte ri o. M in is tr y

of

th e Environment

Ontario 244 pp.

Joedodibroto R 1963.

of model

compounds.

The mechanism

of th e decomposition of Xanthates

PhD. Thesis Syracuse University New York.

Trofimovich E.M.

skaya. 1976.

Kaliya

C

2

-C v

lated

by Raiph

S.H. Rykova M.A. Molchanova and L.B. Aleksandrov

Materialy

po Gigienicheskomv Normalirovahiyv

Ksantogenator

Vode Vodoemor. Gigienina i Sanitariya 6:95-97.

Trans

McElroy Co. Custom

Division

Texas.

Webb }1. H Ruber and G Leduc. 1976. The Tox ic it y o f

Various

Mining

Flotation Reagents to Rainbow Trout Sa1mo

gairdner i .

Water Res.

10:303-306.

Wixson B.

and

N

Gale.

Related to Mining.

1974.

Pages

109-122

in

Water

Resources

Problems

Proc. No. 18 .

American

Water Resources Association.

sodium isopropyl xanthate

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