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VOLUME I
APPENDIX D
STEEL INDUSTRY WASTEWATER POLLUTANTS
Acrylonitrile (3). Acrylonitrile (CH,«CHCN) is an explosive flammable
liquid having a normal boiling point of 77»C and a vapor pressure of
80 mmHg at 20°C. It is miscible with most organic solvents. It is
manufactured by the reaction of propylene with ammonia and oxygen in
the presence of a catalyst. Annual U.S. production is eight hundred
thousand tons.
The major use of acrylonitrile is in the manufacture of copolymers for
the production of acrylic and modacrylic fibers. It is also used in
the plastics, surface coatings, and adhesives industries.
The acute toxicity of acrylonitrile is well known. The compound
appears to exert part of its toxic effect through the release of
inorganic cyanide. Inhalation has been reported to be the major route
of exposure in lethal cases of acrylonitrile poisoning. Toxic
'manifestations of acrylonitrile inhalation include disorders of the
central nervous system and chronic upper respiratory tract irritation.
The next most likely route of exposure is dermal. Dermatologic
conditions include contact allergic dermatitis, occupational eczema
and t.oxoclermia. The least likely route of exposure of acrylonitrile
is through ingestion. Ingestion usually occurs through exposure to
water or aquatic life containing acrylonitrile or exposure to food
products packaged in materials which leach acrylonitrile to the food.
There is suggestive evidence that acrylonitrile is carcinogenic to
humans and animals. NIOSH 1978 states, "...acrylonitrile must be
handled in the workplace as a suspect human carcinogen." Laboratory
rats which had acrylonitrile administered to them through inhalation
and drinking water developed central nervous system tumors and zymbal
gland carcinomas not evident in the control animals. Numerous reports
have been made of the embryotoxicity, mutagenicity, and teratogenicity
of acrylonitrile in laboratory animals.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to acrylonitrile through ingestion of
water and contaminated aquatic organisms, the ambient water
concentration is zero. Concentrations of acrylonitrile estimated to
result in additional lifetime cancer risk at levels of 10~7, 10~* and
10-* are 5.79 x 10~* mg/1, 5.79 x 1C-* mg/1 and 5.79 x 10-* mg/1,
resepctively. If contaminated aquatic organisms alone are consumed
excluding the consumption of water, the water concentration should be
less than 6.52 x 10~J mg/1 to keep tne lifetime cancer risk below
10~5. Limited acute and chronic toxicity data for fresh water aquatic
Preceding page blank
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life show that adverse effects occur at concentrations higher than
those cited for huiran health risks.
Some studies have been reported regarding the behavior of
acrylonitrile in POTW. Biochemical oxidation of acrylonitrile under
laboratory conditions at concentrations of 86-162 mg/1, produced 0, 2,
and 56 percent degradation in 5, 10, and 20 days, respectively, using
ur.acclimated seed cultures. Degradation of 72 percent was produced in
10 days using acclimated seed cultures. Based on these data and
general conclusions relating molecular structure to biochemical
oxidation, it is expected that acrylonitrile will be biochemically
oxidized to a lesser extent than domestic sewage by biological
treatment in POTW. Other reports suggest that acrylonitrile entering
an activated sludge process in concentrations of 50 ppm or greater,
may inhibit certain bacterial processes such as nitrification.
Benzene (4). Benzene (C4H«) is a clear, colorless, liquid obtained
mainly from petroleum feedstocks by several different processes. Some
is recovered from .light oil obtained from coal carbonization gases.
It boils at 80°C and has a vapor pressure of 100 mm Hg at 26°C. It is
slightly soluble in water (1.8 g/1 at 25°C) and it disolves in
hydrocarbon solvents. Annual U.S. production is three to four million
tons.
Most of the benzene used in the U.S. goes into chemical manufacture.
About half of that is converted to ethylbenzene which is used to make
styrene. Some benzene is used in motor fuels.
Benzene is harmful to human health according to numerous published
studies. Most studies relate effects of inhaled benzene vapors.
These effects include nausea, loss of muscle coordination, and
excitement, followed by depression and coma. Death is usually the
result of respiratory or cardiac failure. Two specific blood
disorders are related to benzene exposure. One of these, acute
myelogenous leukemia, represents a carcinogenic effect of benzene.
However, most human exposure data are based on exposure in
occupationed settings and benzene carcinogenisis is not considered to
be firmly established.
Oral administration of benzene to laboratory animals produced
leukopenia, a reduction in number of leukocytes in the blood.
Subcutaneous injection of benzene-oil solutions has produced
suggestive, but not conclusive, evidence of benzene carcinogenisis.
Benzene demonstrated teratogenic effects in laboratory animals, and
mutagenic effects in humans and other animals.
For maximum protection of human health from the potential carcinogenic
effects of exposure to benzene through ingestion of water and
contaminated aquatic organisms, the ambient water concentration is
zero. Concentrations of benzene estimated to result in additional
lifetime cancer risk at levels of 10~7, 10-*, and 10~» are 8 x 10~s
mg/1, 8 x 10~* mg/1, and 8 x 1C-J mg/1, respectively. If contaminated
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aquatic organisms alone are consumed, excluding the consumption of
water, the water concentration should be less than 0.478 mg/1 to keep
the lifetime cancer risk below 10~5. Available data show that adverse
effects on aquatic life occur at concentrations higher than those
cited for human health risks.
Some studies have been reported regarding the behavior of benzene in
POTW. Biochemical oxidation of benzene under laboratory conditions,
at concentrations of 3 to 10 mg/1, produced 24, 27, 24, and 29 percent
degradation in 5, 10, 15, and 20 days, respectively, using
unacclimated seed cultures in fresh water. Degradation of 58, 67, 76,
and 80 percent was produced in the same time periods using acclimated
seed cultures. Other studies produced similar results. Based on
these data and general conclusions relating molecular structure to
biochemical oxidation, it is expected that benzene will be
biochemically oxidized to a lesser extent than domestic sewage by
biological treatment in POTW. Other reports indicate that most
benzene entering a POTW is removed to the sludge and that influent
concentrations of 1 g/1 inhibit sludge digestion. An EPA study of the
fate of toxic pollutants in POTW reveals removal efficiencies of 70 to
98 percent for three POTW where influent benzene levels were 5 x 10~J
to 143 x 10-J mg/1. Four other POTW samples had influent benzene
concentrations of 1 or 2 x 10-* mg/1 and removals appeared
indeterminate because of the limits of quantification for analyses.
There is no information about possible effects of benzene on crops
grown in soils amended with sludge containing benzene.
Hexachlorobenzene (9). Hexachlorobenzene (C,C1*) is a nonflammable
crystalline substance which is virtually insoluble in water. However,
it is soluble in benzene, chloroform, and ether. Hexachlorobenzene
(HCB) has a density of 2.044 g/ml. It melts at 231°C and boils at
323-326°C. Commercial production of HCB in the U.S. was discontinued
in 1976, though it is still generated as a by-product of other
chemical operations. In 1972, an estimated 2425 tons of HCB were
produced in this way.
HexachJorobenzene is used as a fungicide to control fungal diseases in
cereal grains. The main agricultural use of HCB is on wheat seed
intended soley for planting. HCB has been used as an impurity in
other pesticides. It is used in industry as a plasticizer for
polyvinyl chloride as well as a flame retardant. HCB is also used as
a starting material for the production of pentachlorophenol which is
marketed as a wood preservative.
Hexachlorobenzene car. be harmful to human health as was seen in Turkey
from 1955-1959. Wheat that had been treated with HCB in preparation
for planting was consumed as food. Those people affected by HCB
developed cutanea tarda porphyria, the symptoms of which included
blistering and epidermolysis of the exposed parts of the body,
particularly the face and the hands. These syir.ptoms disappeared after
consumption of HCB contaminated bread was discontinued. However, the
HCB which was stored in body fat contaminated maternal r.ilk. As a
result of this, at least 95 percent of the infants feeding on this
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milk died. The fact that HCB remains stored in body fat after
exposure has ended presents an additional problem. Weight loss may
result in a dramatic redistribution of HCB contained in fatty tissue.
If the stored levels of HCB are high, adverse effects might ensue.
Limited testing suggests that hexachlorobenzene is not teratogenic or
mutagenic. However, two animal studies have been conducted which
indicate that HCB is a carcinogen. HCB appears to have multipotential
carcinogenic activity; the incidence of hepatomas,
haemangioendotheliomas and thyroid adenomas was significantly
increased in animals exposed to HCB by comparison to control animals.
For maximum protection of human health from the potential carcinogenic
effects of exposure to hexachlorobenzene through ingestion of water
and contaminated aquatic organisms, the ambient water concentration is
zero. Concentrations of HCB estimated to result in additional
lifetime cancer risk at levels of 10~7, 10~*, and 10~s are 7.2 x 10~»
mg/1, 7.2 x 10-*mg/l, and 7.2 x 10-* mg/1, respectively. If
contaminated aquatic organisms alone are consumed, excluding the
consumption of water, the water concentration should be less than 7.4
x 10~* mg/1 keep the increased lifetime cancer risk below 10"5.
Available data show that adverse effects on aquatic life occur at
concentrations higher than those cited for human health risks.
No detailed study of hexachlorobenzene behavior in POTW is available.
However, general observations relating molecular structure to ease of
degradation have been developed for all of the organic toxic
pollutants. The conclusion reached by study of the limited data is
that biological treatment produces little or no degradation of
hexachlorobenzene. No evidence is available for drawing conclusions
regarding its possible toxic or inhibitory effect on POTW operations.
1,1,1 -Trichloroethane( in. 1 , 1 , 1-Trichloroethane is one of the two
possible trichlorethanes. It is manufactured by hydrochlorinating
vinyl chloride to 1,1-dichloroethane which is then chlorinated to the
desired product. 1, 1,1-Tnchloroethane is a liquid at room
temperature with a vapor pressure of 96 mm Hg at 20°C and a boiling
point of 74°C. Its formula is CCljCHj. It is slightly soluble in
water (0.48 g/1) and is very soluble in organic solvents. U.S.
annual production is greater than one-third of a million tons.
1,1,1-Trichloroethane is used as an industrial solvent and degreasing
agent.
Most human toxicity data for 1,1,1-trichloroethane relates to
inhalation and dermal exposure routes. Limited data are available for
determining toxicity of ingested 1,1,1-trichloroethane, and those data
are all for the compound itself not solutions in water. No data are
available regarding its toxicity to fish and aquatic organisms. For
the protection of hux.an health from the toxic properties of
1,1,1-trichloroethane ingested through the consumption of water and
fish, the ambient water criterion is 18.4 mg/1. If aquatic organisms
alone are consumed, the water concentration should be less than 1030
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mg/1. Available data show that adverse effects in aquatic species can
occur at 18 mg/1.
No detailed study of 1,1,1-trichloroethane behavior in POTW is
available. However, it has been demonstrated that none of the organic
priority pollutants of this type can be broken down by biological
treatment processes as readily as fatty acids/ carbohydrates, 01
proteins.
Biochemical oxidation of many of the organic priority pollutants has
been investigated, at least in laboratory scale studies, at
concentrations higher than commonly expected in municipal wastewater.
General observations relating molecular structure to ease of
degradation have been developed for all of these pollutants. From
study of the limited data, it is expected that I,1,1-trichloroethane
will be biochemically oxidized to a lesser extent than domestic sewage
by biological treatment in POTW. No evidence is available for drawj-.^
conclusions about its possible toxic or inhibitory effect on POTW
operation. However, for degradation to occur a fairly constant input
of the compound would be necessary.
Its water solubility would allow 1,1,1-trichloroethane, present in the
influent and not biodegradable, to pass through a POTW into the
effluent. One factor which has received some attention, but no
detailed study, is the volatilization of the lower molecular weight
organics from POTW. If 1,1,1-trichloroethane is not biodegraded, it
will volatilize during aeration processes in the POTW.
2,4,6-Tri ch1orophenol(21). 2,4,6-Trichlorophenol (C1,C4H,OH,
abbreviated here to 2,4,6 TCP) is a colorless crystalline solid at
room temperature. It is prepared by the direct chlorination of
phenol. 2,4,6-TCP melts at 68°C and is slightly soluble in water (0.8
gm/1 at 25°C). This phenol does not produce a color with
4-aminoantipyrene, therefore does not contribute to the
nonconventional pollutant parameter "Total Phenols." No data were
found on production volumes.
2,4,6-TCP is used as a fungicide, bactericide, glue and wood
preservative, and for antimildew treatment. It is also used for the
manufacture of 2,3,4,6-tetrachlorophenol and pentachlorophenol.
No data were found on human toxicity effects of 2,4,6-TCP. Reports of
studies with laboratory animals indicate that 2,4,6-TCP produced
convulsions when injected interperitoneally. Body temperature was
also elevated. The compound also produced inhibition of ATP
production in isolated rat liver mitochondria, increased mutation rate
in one strain of bacteria, and produced a genetic change in rats. No
studies on teraf.ogenicity were found.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to 2,4,6-trichlorophenol through
ingestion of water and contaminated aquatic organisms, the ambient
water concentration should be zero. The estimated levels which would
i 1
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result in increased lifetime cancer risks of 10~7, 10-*, and 10-» are
1.18 x 10-* mg/1, 1.18 x 1Q-* mg/1, and 1.18 x 10-' mg/1,
respectively. If contaminated aquatic organisms alone are consumed,
excluding the consumption of water, the water concentration should be
less than 3.6 x 10~J mg/1 to keep the increased lifetime cancer risk
below 10-*. Available data show that adverse effects in aquatic
species can occur at 9.7 x. 10-* mg/1.
Although no data were found regarding the behavior of 2,4,6-TCP in
POTW, studies of the biochemical oxidation of the compound have been
made in a laboratory scale at concentrations higher than those
normally expected in municipal wastewaters. Biochemical oxidation of
2,4,6-TCP at 100 mg/1 produced 23 percent degradation using a
phenol-adapted acclimated seed culture. Based on these results, it is
expected that 2,4,6-TCP will be biochemically oxidized to a lesser
extent than domestic sewage by biological treatment in POTW. Another
study indicates that 2,4,6-TCP may be produced in POTW by chlorination
of phenol during normal chlorination treatment.
Para-chloro-meta-cresol(22). Para-chloro-meta-cresol (C1C7H4OH) is
thought to be 4-chloro-3-methyl-phenol \4-chloro-meta-cresol, or 2 ,
chloro-5-hydroxy-toluene), but is also used by some authorities to I
refer to 6-chioro-3-methyl-phenol (6-chloro-meta-cresol, or
4-chloro-3-hydroxy-toluene/, depending on whether the chlorine is
considered to be para to the methyl or to the hydroxy group. It is
assumed for the purposes of this document that the subject compound is
2-chloro-5-hydroxy-toluene. This compound is a colorless crystalline
solid melting at 66-68°C. It is slightly soluble in water (3.8 gm/1)
and soluble in organic solvents. This phenol reacts with
4-aminoantipyrene to give a colored product and therefore contributes
to the nonconventional pollurant parameter designated "Total Phenols."
No information on manufacturing methods or volumes produced was found.
Para-chloro-meta cresol (abbreviated here as PCMC) is marketed as a
microbicide, and was proposed as an antiseptic and disinfectant, more
than forty years ago. It is used in glues, gums, paints, inks,
textiles, and leather goods. PCMC was found in raw wastewaters from
the die casting quench operation from one subcategory of foundry
operations.
Although no hur.an toxicity data are available for PCMC, studies on
laboratory animals have demonstrated that this compound is toxic when
administered subcutaneously and intravenously. Death was preceeded by
severe muscle tremors. At high dosaoes kidney damage occurred. On
the other hand, an unspecified isomer of chlorocresol, presumed to be
PCMC, is used at a concentration of 0.15 percent to preserve mucous
heparin, a natural product administered intervenously as an
anticoagulant. The report does not indicate the total amount of PCMC
typically received. No information was found regarding possible
teratogenicity, or carcinogenic!ty of PCMC. Based on available
organoleptic data, for controlling undesirable taste and odor quality
of ambient water, the est-.-.ated level is 3 mg/1. Available data show
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that adverse effects on aquatic life occur at concentrations as low as
0.03 mg/1.
Two reports indicate that PCMC undergoes degradation in biochemical
oxidation treatments carried out at concentrations higher than are
expected to be encountered in POTW influents. One study showed 59
percent degradation in 3.5 hours when a phenol-adapted acclimated seed
culture was used with a solution of 60 mg/1 PCMC. The other study
showed 100 percent degradation of a 20 mg/1 solution of PCMC in two
weeks in an aerobic activated sludge test system. No degradation of
PCMC occurred under anaerobic conditions. From a review ot limited
data, it is expected that PCMC will be biochemically oxidized to a
lesser extent than domestic sewage by biological treatment in POTWs.
Chloroform(23). Chloroform is a colorless liquid manufactured
commercially by chlorination of methane. Careful control of
conditions maximizes chloroform production, but other products must be
separated. Chloroform boils at 61°C and has a vapor pressure of
200 mm Hg at 25°C. It is slightly soluble in water (8.22 g/1 at 20°C)
and readily soluble in organic solvents.
Chloroform is used as a solvent and to manufacture refrigerent3,
Pharmaceuticals, plastics, and anesthetics. It is seldom used as an
anesthetic.
Toxic effects of chloroform on humans include central nervous system
depression, gastrointestinal irritation, liver and kidney damage and
possible cardiac sensitization to adrenalin. Carcinogenicity has been
demonstrated for chloroform on laboratory animals.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to chloroform through ingest ion of
water and contaminated aquatic organisms, the ambient water
concentration is zero. Concentrations of chloroform estimated to
result in additional lifetime cancer risks at the levels of 10~7,
10-*, and 10-* were 1.89 x 10~» mg/1, 1.89 x 10-* mg/1, and 1.89 x
10"* mg/1, respectively. If contaminated aquatic organisms alone are
consumed, excluding the consumption of water, the water concentration
should be less than 0.157 mg/1 to keep the increased lifetime cancer
risk below 10~5. Available data show that adverse effects on aquatic
life occur at concentrations higher than those cited for human health
risks.
Few data are available regarding the behavior of chloroform in a POTW.
However, the biochemical oxidation of this compound was studied in one
laboratory scale study at concentrations higher than those expected to
be contained by most municipal wastewaters. After 5, 10, and 20 days
no degradation of chloroform was observed. The conclusion reached is
that biological treatment produces little or no removal by degradation
of chloroform in POTW. An EPA study of the fate of toxic pollutants
in POTW reveals removal efficiencies of 0 to 80 percent for influent
concentrations ranging from 5 to 46 x 10~J mg/1 at seven POTW.
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The high vapor pressure of chloroform is expected to result in
volatilization of the compound from aerobic treatment steps in POTW.
Remaining chloroform is expected to pass through into the POTW
effluent.
2-Chlorophenol(24). 2-Chlorophenol (C1C»H4OH), also called
ortho-chlorophenol, is a colorless liquid at room temperature,
manufactured by direct chlorination of phenol followed by distillation
to separate it from the other principal product, 4-chlorophenol.
2-Chlorophenol solidifies below 7°C and boils at 176°C. It is soluble
in water (28.5 gm/1 at 20°C) and soluble in several types of organic
solvents. This phenol gives a strong color with 4-aninoantipyrene and
therefore contributes to the nonconventional pollutant parameter
"Total Phenols." Production statistics could not be found.
2-Chlorophenol is used almost exclusively as a chemical intermediate
in the production of pesticdes and dyes. Production of some phenolic
resins uses 2-chlorophenol.
Very few data are available on which to determine the toxic effects of
2-chlorophenol on humans. The compound is more toxic to laboratory
mammals when administered orally than when administered subcataneously
or intravenously. This affect is attributed to the fact that the
compound is almost completely in the un-ionized state at the low ph of
the stomach and hence is more readily absorbed into the body. Initial
symptoms are restlessness and increased respiration rate, followed by
motor weakness and convulsions induced by noise or touch. Co.ta
kidney, liver, and intestinal damar,?
were found which addressed the
of 2-chlorophenol. Studies of
of carcinogenic activity of other
carcinogens were conducted by dermal application. Results do not bear
a deterir.inable relationship to results of oral administration studies.
follows. Following lethal doses
were observed. No studies
teratogenicity or mutagenicity
2-chlorophenol as a promoter
For controlling undesirable taste and odor quality of ambient water
due to the organoleptic properties of 2-chlorophenol in water, the
estimated level is 1 x 10~* mg/1. Available data show that adverse
effects on aquatic life occur at concentrations higher than that cited
for organaleptic effects.
Data on the behavior of 2-chlorophenol in POTW are not available.
However, laboratory scale studies have been conducted at
concentrations higner than those expected to be found in municipal
wastewaters. At 1 mg/1 of 2-chlorophenol, an acclimated culture
produced 100 percent degradation by biochemical oxidation after 15
days. Another study showed 45, 70, and 79 percent degradation by
biochemical oxidation after 5, 10, and 20 days, respectively. Froz
study of these liirited data, and general observations on all organic
priority pollutants relating molecular structure to ease of
biochemical oxidation, it is expected that 2-chlorophenol will be
biochemically oxidized to a lesser extent than domestic sewage by
biological treatment in POTW. Undegraded 2-chlorophenol is expected
to pass through POTW into, the effluent because of the water
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solubility. Some 2~chlorophenol is also expected to be generated by
chlorination treatments of POTW effluents containing phenol.
2,4- Dimethylphenol(34). 2,4-Dimethylphenol (2,4-DMP), also called
2,4-xylenol, is a colorless, crystalline solid at room temperature
(25°C), but melts at 27 to 28<>C. 2,4-DMP is slightly soluble in water
and, as a weak acid, is soluble in alkaline solutions. Its vapor
pressure is less than 1 mm Hg at room temperature.
2,4-DMP is a natural product, occurring in coal and petro'eum sources.
It is used commercially as a intermediate for manufacture of
pestic;des, dystuffs, plastics and resins, and surfactants. It is
found in the water runoff from asphalt surfaces. It can find its way
into the wastewater of a manufacfuring plant from any of several
adventitious sources.
Analytical procedures specific to this compound are used for its
identification and quantification in wastewaters. This compound does
not contribute to "Total Phenol" determined by the 4-aminoantipyrene
method.
Three methylphenol isomers (cresols) and six dimethylphenol isomers
(xylenols) generally occur together in natural products, industrial
processes, commercial products, and phenolic wastes. Therefore, data
are not available for human exposure to 2,4-DMP alone. In addition to
this, most mammalian tests for toxicity of individual dimethylphenol
isomers have been conducted with isomers other than 2,4-DMP.
In general, the mixtures of phenol, methylphenols, and dimethylphenols
contain compounds which produced acute poisoning in laboratory
animals. Symptoms were difficult breathing, rapid muscular spasms,
disturbance of motor coordination, and assymetrical body position. In
a 1977 National Academy of Science publication the conclusion was
reached that, "In view of the relative paucity of data on the
mutagenicity, carcinogenicity, teratogenicity, and long term oral
toxicity of 2,4 dimethylphenol, estimates of the effects of chronic
oral exposure at low levels cannot be made with any confidence." No
ambient water quality criterion can be set at this time. In order to
protect public health, exposure to this compound should be minimized
as soon as possible.
Toxicity data for fish and freshwater aquatic life are limited. Acute
toxicity to freshwater aquatic life occurs at 2,4-dimethylphenol
concentrations of 2.12 ng/1. For controlling undesirable taste and
odor quality of ambient water due to the organoleptic effects of
2,4-dimethylphenol in water the estimated level is 0,4 mg/1.
The behavior of 2,4-DMP in POTW has not been studied. As a weak acid
its behavior may be somewhat dependent on the pH of the influent to
the TOTW. However, over the normal limited range of POTW pH, little
effect of pH would be expected.
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m
Biological degradability of 2,4-DMP as determined in one study, showed
94.5 percent biochemical oxidation after 110 hours using an adapted
culture. Thus, it is expected that 2,4-DMP will be biochemically
oxidized to about the sane extent as domestic sewage by biological
treatment in POTW. Another study determined that persistance of
2,4-DMP in the environment is low, thus any of the compound which
remained in the sludge or passed through the POTW into the effluent
would be degraded within moderate length of time (estimated as 2
months in the report).
2J4-Dinitrotoluene(35). 2,4-Dinitrotoluene ((NO,)ZC«H3CH3), a yellow
crystalline compound, is icanufactured as a coproduct with the 2,6
isomer by nitraLion of nitrotoluene. It melts at 7i°C.
2,4-Dinitrotoluene is insoluble in water (0.27 g/1 at 22°C) and
soluble in a number of organic solvents. Production data for the
2,4-isomer alone are not available. The 2,4-and 2,6-isomers are
manufactured in an 80:20 or 65:35 ratio, depending on the process
used. Annual U.S. commercial production is about 150 thousand tons of
the two isomers. Unspecified amounts are produced by the U.S.
government and further nitrated to trinitrotoluene (TNT) for military
use.
The major use of the dinitrotoluer-2 mixture is for production of
toluene diisocyanate used to make polyurethanes. Another use is in
production of dyestuffs.
The toxic effect of 2,4-dinitrotoluene in humans is primarily
methemoglobinemia (a blood condition hindering oxygen transport by t'.e
blood). Symptoms depend on severity of the disease, but incli.de
cyanosis, dizziness, pain in joints, headache, and loss of appetite in
workers inhaling the compound. Laboratory animals fed oral doses of
2,4-dinitrotoluene exhibited many of the same symptoms. Aside froT,
the effects in red blood cells, effects are observed in the nervous
system and testes.
Chronic exposure to 2,4-dinitrotoluene may produce liver damage and
reversible anemia. No data wer*? found on teratogenicity of this
compound. Mutagenic data are limited and are regarded as confusing."
Data resulting from studies of carcinogenici ty of 2, 4-dini trotoluer.e
point to a need for further testing for this property.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to 2,4-dinitrotoluene throuuh
ingestion of water and contaminated aquatic organisms, the ambient
water concentration is zero. Concentrations of 2,4-dinitrotoluene
estimated to result in additional lifetime cancer risk at risk levels
of 10~7, 10-*, and 10-* are 1.11 x 1C-* mg/1, 1.11 x 10~4 ing/1, and
1.11 x 10~3 rrg/1, respectively. If aquatic organises alone are
consumed, the water concentration should be less than 0.091 mg/1 to
keep the increased lifetime cancer risk below 10~5. Available data
show that adverse effects in aquatic life occur at concentrations
higher than those cited for human health risks.
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V
Data on the behavior of 2,4-dinitrotoluene in POTW are not available.
However, biochemical oxidation of 2,4-dinitrotoluene was investigated
on a laboratory scale. At 100 mg/I of 2,4-dinitrotoluene, a
concentration considerably higher than that expected in municipal
wastewaters, biochemical oxidation by an acclimated, phenol-adapted
seed culture produced 52 percent degradation in three hours. Based on
this limited information and general observations relating molecular
structure to ease of degradation for all the organic toxic pollutants,
it is expected that 2,4-dinitrotoluene will be biochemically oxidized
to about the sane extent as domestic sewage by biological treatment
in POTW. No information is available regarding possible interference
by 2,4-dinitrotoluene in POTW treatasnt processes, or on the possible
detrimental effect on sludge -:sed to amend soils in which food crops
are grown.
2,6-Dinitrotoluene(36). 2,6-Dinitrotoluene [(NO,),C«H,CH3) is a
crystallinesolidproduced as a coproduct with 2,4-dinitrotoluene by
nitration of nitrotoluene. !t pelts at 66C. No solubility or vapor
pressure data are given in the literature, but this compound is
expected to be insoluble just as the 2,4-dinitrotoluene isomer is
(0.27 g/1 at 22C). Production data for the 2,6-isomer are not
available. The 2,4- and 2,6- isosers are manufactured in an 80:20 or
65:35 ratio depending on the process used. Annual U.S. commercial
production is about 150 thousand tons of the two isomers. Unspecified
ar-ounts are produced by the U.S. government and further nitrated to
trinitrotoluene (TNT) for military use.
The major use of the dinitrotoluene mixture is for production of
toluene diisocyanate used to make polyurethanes. Another use is in
production of dyestuffs.
No toxicity data are available in the literature for
2,6-dinitrotoluene. The 2,4-isoser is toxic and is classed as a
potential carcinogen on the basis of tumerogenic effects and other
considerations. No ambient water criterion has been established for
2,6-dinitrotoluene.
Data on the behavior of 2,6-dinitrotoluene in POTW are not available.
Biochemical oxidation of many of the organic priority pollutants have
been investigated, at least in laboratory srale studies, at
concentrations higner than those expected to be contained by most
municipal wastewaters. General observations have been developed
relating molecular structure to ease of degradation for all the
organic toxic pollutants. Based upon study of the limited data, it is
expected that 2,6-dinitrotoiuene will be biochemically oxidizeJ to a
lesser extent than domestic sewage by biological treatment in POTW.
No information is available .regarding possible interferance by
2,6-dinitrotoluene in POTW processes, or the possible detrimental
effect on sludge used to arend soils in which crops are grown.
Ethvlhenzene' 35•. Ethylbenzene is a colorless, flammable liquid
manufactured corTercial iy frcr benzene and ethylene. Approximately
half of the benzene used in the U.S. goes into the manufacture of more
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than three million tons of ethylbenzene annually. Ethylbenzene boils
at 136°C and has a vapor pressure of 7 mm Hg at 20°C. It is slightly
soluble in water (O.U g/1 at 15°C) and is very soluble in organic
solvents.
About 98 percent of the ethylbenzene produced in the U.S. goes into
the production of styrene, much of which is used in the plastics and
synthetic rubber industries. Ethylbenzene is a constituent of xylene
mixtures used as diluents in the paint industry, agricultural
insecticide sprays, and gasoline blends.
Although humans are exposed to ethylbenzene from a variety of sources
in the environment, little information on effects of ethylbenzene in
man or animals is available. Inhalation can irritate eyes, affect the
respiratory tract, or cause vertigo. In laboratory animals
ethylbenzene exhibited low toxicity. There are nc data available on
teratogenicity, mutagenicity, or carcinogenicity of ethylbenzene.
Criteria are based on data derived from inhalation exposure limits.
For the protection of human health from the toxic properties of
ethylbenzene ingested through water and contaminated aquatic
organisms, the ambient water criterion is 1.4 mg/1. If contaminated
aquatic organisms alone are consumed, excluding the consumption of
water, the ambient water criterion is 3.28 mg/1. Available data show
that at concentrations of 0.43 mg/1, adverse effects on aquatic life
occur.
The behavior of ethylbenzene in POTW has not been studied in detail.
Laboratory scale studies of the biochemical oxidation of ethylbenzene
at concentrations greater than would normally be found in municipal
wastewaters have demonstrated varying degrees of degradation. In one
study with phenol-acclimated seed cultures 27 percent degradation was
observed in a half day at 250 mg/1 ethyl- bezene. Another study at
unspecified conditions showed 32, 38, and 45 percent degradation after
5, 10, and 20 days, respectively. Based on these results and general
observations relating molecular structure to ease of degradation, it
is expected that ethylbenzene will be biochemically oxidized to a
lesser extent than domestic sewage by biological treatment in POTW.
An EPA study of seven POTW showed removals of 77 to 100 percent in
five POTW having influent ethylbenzene concentrations of 10 to 44 x
10-3 mg/1. The other two POTW had influent concentrations of 2 x 10~J
mg/1 or less. Other studies suggest that most of the ethylbenzene
entering a POTW is removed from the aqueous stream to the sludge. The
ethylbenzene contained in the sludge removed from the POTW may
volatilize.
Fluoranthene(39). Fluoranthene (1,2-benzacenaphthene) is one of the
coxpounds called polynuclear aromatic hydrocarbons (PAH). A pale
yellow solid at room temperature, it melts at 11 1 °C and has <*
negligible vapor pressure at 25°C. Water solubility is low (0.2
mg/1). Its molecular formula is C,6H,0.
\
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Fluoranthene, along with many other PAH's, is found throughout the
environment. It is produced by pyrolytic processing of organic raw
materials, such as coal and petroleum, at high temperature (coking
processes). It occurs naturally as a product of plant biosyntheses.
Cigarette smoke contains fluoranthene. Although it is not used as the
pure compound in industry, it has been found at relatively higher
concentrations (0.002 mg/1) than most other PAH's in at least one
industrial effluent. Furthermore, in a 1977 EPA survey to determine
levels of PAH in U.S. drinking water supplies, none of the 110 samples
analyzed showed any PAH other than fluoranthene.
Experiments with laboratory animals indicate that fluoranthene
presents a relatively low degree of toxic potential from acute
exposure, including oral administration. Where death occured, no
information was reported concerning target organs or specific cause of
death.
There is no epidemiological evidence to prove that PAH in general, and
fluoranthene, in particular, present in drinking water are related to
the development of cancer. The only studies directed toward
determining carcinogenicity of fluoranthene have been skin tests on
laboratory animals. Results of these tests show that fluoranthene has
no activity as a complete carcinogen (i.e., an agent which produces
cancer when applied by itself, but exhibits significant
cocarcinogenicity (i.e., in combination with a carcinogen, it
increases the carcinogenic activity).
Based on the limited animal study data, and following an establishing
procedure, the ambient water criterion for fluoranthene through water
and contaminated aquatic organisms is determined to be 0.042 mg/1 for
the protection of human health from its toxic properties. If
contaminated aquatic organisms alone are consumed, excluding the
consumption of water, the ambient water criterion is 0.054 mg/1.
Available data show that adverse effects on aquatic life occur at
concentrations of 0.016 mg/1.
Results of studies of the behavior of fluoranthene in conventional
sewage treatment processes found in POTW have been published. Removal
of fluoranthene during primary sedimentation was found to be 62 to 66
percent (from an initial value of 0.00323 to 0.0435 mg/1 to a final
value of 0.00122 to 0.0146 mg/1), and the removal was 91 to 99 percent
(final values of 0.00028 to O.OC026 mg/1) after biological
purification with activated sludge processes.
A review was made of data on biochemical oxidation of many of the
organic priority pollutants investigated in laboratory scale studies
at concentrations higher than would normally be expected in municipal
wastewater. General observations relating molecular structure to ease
of degradation have been developed for all of these pollutants. The
conclusion reached by study of the limited data is that biological
treatment produces little or no degradation of fluoranthene. The same
study however concludes that fluoranthene would be readily removed by
filtration and oil water separation and other methods which rely on
x
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•\
water insolubility, or adsorption on other particulate surfaces. This
latter conclusion is supported by the previously cited study showing
significant removal by primary sedimentation.
No studies were found to give data on either the possible interference
of fluoranthene with POTW operation, or the persistence of
fluoranthene in sludges on POTW effluent waters. Several studies have
documented the ubiquity of fluoranthene in the environment and it
cannot be readily determined if this results from persistence of
anthropogenic fluoranthene or the replacement of degraded fluoranthene
by natural processes such as biosynthesis in plants.
Isophoronei 54 *. Isophorone is an industrial chemical produced at a
level of tens of millions of pounds annually in the U.S. The chemical
name for isophcrone is 3,5,5-trimethyl-2-cyclohexen-l-one and it is
also known as trimethyl cyclohexanone and isoacetcphorone. The
formula is C4H5(CHj),0. Normally, it is produced as the gamma isomer;
technical grades contain about 3 percent of the beta isomer
(3,5-5-trimethyl-3-cyclohexen-l-one). The pure gamma isomer is a
water-white liquid, with vapor pressure less than 1 mm Hg at room
temperature, and a boiling point of 215.2°C. It has a camphor- or
peppermint-1ike odor and yellows upon standing. It is slightly
soluble (12 mg/1) in water and dissolves in fats and oils.
Isophorone is synthesized from acetone and is used commercially as a
solvent or cosolvent for finishes, lacquers, polyvinyl and
nitrocellulose resins, pesticides, herbicides, fats, oils, and gums.
It is also used as a chemical feedstock.
Because isophorone is an industrially used solvent, most toxicity data
are for inhalation exposure. Oral administration to laboratory
animals in two different studies revealed no acute or chronic effects
during 90 days, and no hematological or pathological abnormalities
were reported. Apparently, no studies have been completed on the
carcinogenicity of isophorone.
Isophorone does undergo bioconcentration in the lipids of aquatic
organisms and fish.
The ambient water criterion for isophorone ingested through
consumption of water and fish is determined to be 5.2 mg/1 foe the
protection of human health from its toxic properties. If contaminated
aquatic organisms alone are consumed, excluding the consumption of
water, the asr.b\ent water criteria is 520 mg/i. Available data show
that adverse effects in aquatic life occur at concentrations as low as
12.9 mg-1.
The behavior of isophorone in POTW has not been studied. However, the
biochemical oxidation of many of the organic priority pollutants has
been investigated in laboratory-scale studies at concentrations higher
than would normally be expected in municipal wastewater. General
observations relating molecular structure to ease of deqradation have
been developed tor all of these pollutants. Based on the study of the
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limited data, it is expected that isophorone will be biochemically
oxidized to a lesser extent than domestic sewage by biological
treatment in POTW. This conclusion is consistent with the findings of
an experimental study of microbiological degradation of isophcrone
which showed about 45 percent biooxidation in 15 to 20 days in
domestic wastewater, but only 9 percent in salt water. No data were
found on the persistence of isophorone in sewage sludge.
Naphthalene(55). Naphthalene is an aromatic hydrocarbon with two
orthocondensed benzene rings and a molecular formula of C,0Ha. As
such it is properly classed as a polynuclear aromatic hydrocarbon
(PAH). Pure naphthalene is a white crystalline solid melting at 80°C.
For a solid, it has a relatively high vapor pressure (0.05 mm Hg at
20°C), and moderate water solubility (19 mg/1 it 20°C). Naphthalene
is the most abundant single component of coal tar. Production is more
than a third of a million tons annually in the U.S. About three
fourths of the production is used as feedstock for phthalic anhydride
manufacture. Most of the remaining production goes into manufacture
of insecticide, dystuffs, pigments, and Pharmaceuticals. Chlorinated
and partially hydrogenated naphthalenes are used in some solvent
mixtures. Naphthalene is also used as a moth repellent.
Naphthalene, ingested by humans, has reportedly caused vision loss
(cataracts), hemolytic anemia, and occasionally, renal disease. These
effects of naphthalene ingestion are confirmed by studies on
laboratory animals. No carcinogenicity studies are available which
can be used to demonstrate carcinogenic activity for naphthalene.
Naphthalene does bioconcentrate in aquatic organisms.
The available data base is insufficient to establish an ambient water
criterion for the protection of human health from the toxic properties
of naphthalene. Available data show that adverse effects on aquatic
life occur at concentrations as low as 0.62 mg/1.
Only a limited number of studies have been conducted to determine the
effects of naphthalene on aquatic organisms. The data from those
studies show only moderate toxicity.
Naphthalene has been detected in sewage plant effluents at
concentrations up to 22 ••g/'l in studies carried out by the U.S. EPA.
Influent levels were not reported. The behavior of naphthalene in
POTW has not been studied. However, recent studies have determined
that naphthalene will accumulate in sediments at 100 times the
concentration in overlying water. These results suggest that
naphthalene will be readily removed by primary and secondary settling
in POTW, if it is not biologically degraded.
Biochemical oxidation of many of the organic priority pollutants has
been investigated in laboratory-scale studies at concentrations higher
than would normally be expected in municipal wastewater. General
observations relating molecular structure to ease of degradation have
been developed for all of these pollutants. Based on the study of the
limited data, it is expected that naphthalene will be biochemically
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oxidized to about the same extent as domestic sewage by biological
treatment in POTW. One recent study has shown that microorganisms can
degrade naphthalene, first to a dihydro compound, and ultimately to
carbon dioxide and water.
2-Nitrophenol(57) . 2-Nitrophenol (NO,C«H4OH), also called
ortho-nitrophenol, is a light yellow crystalline solid, manufactured
commercially by hydrolysis of 2-chloro-nitrobenzene with aqueous
sodium hydroxide. 2-Nitrophenol melts at 45°C and has a vapor
pressure of 1 mm Hg at 49°C. 2-Nitrophenol is slightly soluble in
water (2.1 g/1 at 20°C) and soluble in organic solvents. This phenol
does not react to give a color with 4-aminoantipyrene, and therefore
does not contribute to the nonconventional pollutant parameter "Total
Phenols. U.S. annual production is five thousand to eight thousand
tons.
The principal use of ortho-nitrophenol is to synthesize
ortho-aminophenol, ortho-nitroanisole, and other dyestuff
intermediates.
The toxic effects of 2-nitrophenol on humans have not been extensively
studied. Data from experiments with laboratory animals indicate that
exposure to this compound causes kidney and liver damage. Other
studies indicate that the compound acts directly on cell membranes,
and inhibits certain enzyme systems i_n vitro. No information
regarding potential teratogencity was found. Available data indicate
that this compound does not pose a mutagenic hazard to humans. Very
limited data for 2-nitrophenol do not reveal potential carcinogenic
effects.
The available data base is insufficient to establish an ambient water
criterion for protection of human health from exposure to
2-nitrophenoi. No data are available on which to evaluate the
adverse effects of 2-nitrophenol on aquatic life.
Data on the behavior of 2-nitrophenol in POTW were not available.
However, laboratory-scale studies have been conducted at
concentrations higher than those expected to be found in municipal
wastewater. Biochemical oxidation using adapted cultures from various
sources produced 95 percent degradation in three to six days in one
study. Similar results were reported for other studies. Based on
these data, and general observations relating molecular structure to
ease of biological oxidation, it is expected that 2-nitrophenol will
be biochemically oxidized to a lesser extent than domestic sewage by
biological treatment in POTWs.
4,6-dinitro-o-cresol(6O. 4,6-dinitro-o-cresol (DNOC) is a yellow
crystalline solid derived from o-cresol. DNOC melts at 85.8°C and has
a vapor pressure of 0.000052 mm Hg at 20°C. DNOC is sparingly soluble
in water (ICO mg/1 at 20°C), while it is readily soluble in alkaline
aqueous solutions, ether, acetone, and alcohol. DNOC is produced by
sulfonation of o-cresol followed by treatment with nitric acid.
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DNOC is used primarily as a blossom thinning agent on fruit trees and
as a fungicide, insecticide and miticide on fruit trees during the
dormant season. It is highly toxic to plants in the growing stage.
DNOC is not manufactured in the U.S. as an agricultural chemical.
Imports of DNOC have been decreasing recently with only 30,000 Ibs
being imported in 1976.
While DNOC is highly toxic to plants, it is also very toxic to humans
and is considered to be one of the more dangerous agricultural
pesticides. The available literature concerning humans indicates that
DNOC may be absorbed in acutely toxic amounts through the respiratory
and gastrointestinal tracts and through the skin, and that it
accumulates in the blood. Symptoms of poisoning inlude profuse
sweating, thirst, loss of weight, headache, malaise, and yellow
staining to the skn, hair, sclera, and conjunctiva.
There is no evidence to suggest that DNOC is teratogenic, mutagenic,
or carcinogenic. The effects of DNOC in the human due to chronic
exposure are basically the same as those effects resulting from acute
exposure. Although DNOC is considered a cumulative poison in humans,
cataract formation is the only chronic effect noted in any human or
experimental animal study. It is believed that DNOC accumulates in
the human body and that toxic symptoms may develop when blood levels
exceed 20 mg/kg.
For the protection of human health from the toxic properties of
dinitro-o-cresol ingested through water and contaminanted aquatic
organisms, the ambient water criterion is determined to be 0.0134
mg/1. If contaminated aquatic organisms alone are consumed, excluding \
the consumption of water, the ambient water criterion is determined to
be 0.765 mg/1. No data are available on which to evaluate the adverse
effects of 4,6-dinitro-o-cresol on aquatic life.
Some studies have been reported regarding the behavior of DNOC in
POTW. Biochemical oxidation of DNOC under laboratory conditions at a
concentration of 100 mg/1 produced 22 percent degradation in 3.5
hours, using acclimated phenol adapted seed cultures. In addition,
the nitro group in the number 4 (para) position seems to impart a
destabilizing effect on the molecule. Based on these data and general
conclusions relating molecular structure to biochemical oxidation, it
is expected that 4,6-dinitro-o-cresol will be biochemically oxidized
to a lesser extent than domestic sewage by biological treatment in
POTW.
Pentachlorophenol(64) . Pentachlorophenol (C.CljOH) is a white
crystalline solid produced coT.mercial ly by chlonnation of phenol or
polychlorophenols. U.S. annual production is in excess of 20,000
tons. Pentachlorophenol melts at 190°C and is slightly soluble in
water (14 mg/1). Pentachlorophenol is not detected by the 4-amino
antipyrene method.
Pentachlorophenol is a bactericide and fungacide and is used for
preservation of wood and wood products. It is competative with
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creosote in that application. It is also used as a preservative in
glues, starches, and photographic papers. It is an effective algicide
and herbicide.
Although data are available on the human toxicity effects of penta-
chlorophenol, interpretation of data is frequently uncertain.
Occupcitional exposure observations must be examined carefully because ]
exposure to pentachlorophenol is frequently accompained by exposure to 1
other wood preservatives. Additionally, experimental results and f
occupational exposure observations must be examined carefully to make |
sure that observed effects are produced by the pentachlorophenol |
itself and not by the by-products which usually contaminate
pentachlorophenol.
Acute and chronic toxic effects of pentachlorophenol in humans are
similar; muscle weakness, headache, loss of appetite, abdominal pain, j
weight loss, and irritation of skin, eyes, and respiratory tract. j -
Available literature indicates that pentachlorophenol does not I.
accumulate in body tissues to any significant extent. Studies on j
laboratory animals of distribution of the compound in body tissues <
showed the highest levels of pentachlorophenol in liver, kidney, and !
intestine, while the lowest levels were in brain, fat, muscle, and ]
bone. \ r
I ,•
Toxic effects of pentachlorophenol in aquatic organisms are much ;.
greater at pH of 6 where this weak acid is predominantly in the
undissociated form than at pH of 9 where the ionic form predominates. •
Similar results were observed in mammals; where oral lethal doses of !
pentachlorophenol were lower when the compound was administered in f-
hydrocarbon solvents (un-ionized form) than when it was administered ]
as the sodium salt (ionized form) in water !
There appear to be no significant teratogenic, mutagenic, or 1
carcinogenic effects of pentachlorophenol. I
i
For the protection of human health from the toxic properties of penta- •
chlorophenol ingested through water and through contaminated aquatic i
organisms, the ambient water quality criterion is determined to be j
1.01 mg/1. If contaminated aquatic organisms alone are consumed,
excluding the consumption of water, the ambient water criterion is
determined to be 29.4 mg/1. Available data show that adverse effects
on aquatic life occur at concentration as low as 0.0032 mg/1.
Only limited data are available for reaching conclusions about the '
behavior of pentachlorophenol in POTW. Pentachlorophenol has been
found in the influent to POTW. In a study of one POTW the mean
removal was 59 percent over a 7 day period. Trickling filters removed
44 percent of the influent pentachlorophenol suggesting that
biological degradation occurs. The same report compared removal of \
pentachlorophenol of the same plant and two additional POTW on a later
date and obtained values of 4.4, 19.5 and 28.6 percent removal, the
last value being for the plant which was 59 percent removal in the
original study. Influent concentrations of pentachloropehnol ranged /
1
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^ \
,*
from 0.0014 to 0.0046 mg/1. Other studies, including the general
review of data relating molecular structure to biological oxidation,
indicate that pentachlorophenol is not biochemically oxidized by
biological treatment processes in POTW. Anaerobic digestion processes
are inhibited by 0.4 mg/1 pentachlorophenol.
The low water solubility and low volatility of pentachloro- phenol
lead to the expectation that most of the compound will remain in the
sludge in a POTW. The effect on plants grown on land treated with
sludge containing pentachlorophenol is unpredicatable. Laboratory
studies show that this compound affects crop germination at 5.4 mg/1.
However, photodecomposition of pentachlorophenol occurs in sunlight.
The effects of the various breakdown products which may remain in the
soil was not found in the literature.
Phenol(65). Phenol, also called hydroxybenzene and carbolic acid, is
a clear, colorless, hygroscopic, deliquescent, crystalline solid at
room temperature. Its melting point is 43°C and its vapor pressure at
room temperature is 0.35 mm Hg. It is very soluble in water (67 gm/.l
at 16°C) and can be dissolved in benzene, oils, and petroleum solids.
Its formula is C4H5OH.
Although a small percent of the annual production of phenol is derived
from coal tar as a naturally occuring product, most of the phenol is
synthesized. Two of the methods are fusion of benzene sulfonate with
sodium hydroxide, and oxidation of cumene followed by clevage with a
catalyst. Annual production in the U.S. is in excess of one million
tons. Phenol is generated during distillation of wood and the
microbiological decomposition of organic matter in the mammalian
intestinal tract.
Phenol is used as a disinfectant, in the manufacture of resins,
dyestuffs, and Pharmaceuticals, and in the photo processing industry.
Phenol was detected on only one day in one coil coating raw waste
stream out of 14 days of sampling and analysis at II coil coating
plants. In this discussion, phenol is the specific compound which is
separated by methylene chloride extraction of an acidified sample and
identified and quantified by GC/MS. Phenol also contributes to the
"Total Phenols", discussed elsewhere which are determined by the 4-AAP
colorimetric method.
Phenol exhibits acute and sub-acute toxicity in humans and laboratory
animals. Acute oral doses of phenol in humans cause sudden collapse j
and un- consciousness by its action on the central nervous system. I
Death occurs by respiratory arrest. Sub-acute oral doses in mammals \
are rapidly absorbed then quickly distributed to various organs, then j
cleared from the body by urinary excretion and metabolism. Long term !•
exposure by drinking phenol contaminated water has resulted in j
statistically significant increase in reported cases of diarrhea, !
mouth sores, and burning of the mouth. In laboratory animals long !
term oral administration at low levels produced slight liver and !
kidney damage. No reports were found regarding carcinogenicity of I
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phenol administered orally - ell carcinogenicity studies were skin
tests.
For the protection of human health from phenol ingested through water
and through contaminated aquatic organisms the ambient water criterion
is determined to be 3.5 mg/1. If contaminated aquatic organisms alone
are consumed, excluding the consumption of water, the ambient water
criterion is 769 mg/1. Available data show that adverse effects in
aquatic life occur at concentrations as low as 2.56 mg/1.
Data have been developed on the behavior of phenol in POTW. Phenol is
biodegradable by biota present in POTW. The ability of a POTW to
treat phenol-bearing influents depends upon acclimation of the biota
and the constancy of the phenol concentration. It appears that an
induction period is required to build up the population of organisms
which can degrade phenol. Too large a concentration will result in
upset or pass through in the POTW, but the specific level causing
upset depends on the immediate past history of phenol concentrations
in the influent. Phenol levels as high as 200 mg/1 have been treated
with 95 percent removal in POTW, but more or less continuous presence
of phenol is necessary to maintain the population of microorganisms
that degrade phenol. An EPA study of seven POTWs revealed that only
three POTW showed a decrease in phenol concentration between influent
(14, 1, and 1 x 10~» mg/1) and effluent (1 x 10-J mg/1, and 0,
respectively).
Phenol which is not degraded is expected to pass through the POTW
because of its very high water solubility. However, in POTW where
chlorination is practiced for disinfection of the POTW effluent,
chlorination of phenol may occur. Tne products of that reaction may
be priority pollutants.
The EPA has developed data on influent and effluent concentrations of
total phenols in a study of 103 POTW. However, the analytical
procedure was the 4-AAP method mentioned earlier and not the GC/MS
method specifically for phenol. Discussion of the study, which of
course includes phenol, is presented under the pollutant heading
"Total Phenols."
Phthalate Ester.- ( 66-71) . Phthalic acid, or 1, 2-benzenedicarboxyl ic
acid, is one of three isomeric benzenedicarboxylic acids produced by
the chemical industry. The other two isomer^c forms are called
isophthalic and terephathalic acias. The formula for all three acids
is C4H4(COOH;a. Some esters of phthalic acid are designated as toxic
pollutants. They will be discussed as a group here, and specific
properties of individual phthalate esters will be discussed
afterwards.
Phthalic acid esters are manufactured in the U.S. at an annual rate in
excess of 1 billion pounds. They are used as plasticizers - primarily
in the production of polyvinyl chloride (PVC) resins. The most widely
used phthalate plasticizer is bis (2-ethylhexyli phthalate (66) which
accounts for nearly one third of the phthalate esters produced. This
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7
particular ester is commonly referred to as dioctyi ahthalate (OOP)
and should not be confused with one of the less used esters,
di-n-octyl phthalate (69), which is also used as a plastcizer. In
addition to these two isomeric dioctyi phthalates, four other esters,
also used primarily as plasticizers, are designated as priority
pollutants. They are: butyl benzyl phthalate (67), di-n-butyl
phthaiate (68), diethyl phthalate (70), and dimethyl phthalate (71).
Industrially, phthalate esters are prepared from phthalic anhydride
and the specific alcohol to form the ester. Some evidence is
available suggesting that phthalic acid esters also may be synthesized
by certain plant and animal tissues. The extent to which this occurs
in nature is not known.
Phthalate esters used as plasticizers can be present in concentrations
up to 60 percent of the total weight of the PVC plastic. The
plasticizer is not linked by primary chemical bonds to the PVC resin.
Rather, it is locked into the structure of intermeshing polymer
molecules and held by van der Waals forces. The result is that the
plasticizer is easily extracted. Plasticizers are responsible for the
odor associated with new plastic toys or flexible sheet that has been
contained in a sealed package.
Although the phthalate esters are not soluble or are only very
slightly soluble in water, they do migrate into aqueous solutions
placed in contact with the plastic. Thus industrial facilities with
tank linings, wire and cable coverings, tubing, and sheet flooring of
PVC are expected to discharge some phthalate esters in their raw
waste. In addition to their use as plasticizers, phthalate esters are
used in Ijbricating oils and pesticide carriers. These also can
contribute to industrial discharge of phthalate esters.
From the accumulated data on acute toxicity in animals, phthalate
esters may be considered as having a rather low order of toxicity.
Human toxicity data are limited. It is thought that the toxic effects
of the esters is most likely due to one of the metabolic products, in
particular the monoester. Oral acute toxicity in animals is greater
for the lower molecular weight esters than for the higher molecular
weight esters.
Orally administered phthalate esters generally produced enlarging of
liver and kidney, and atrophy of testes in laboratory animals.
Specific esters produced enlargement of heart and brain, spleenitis,
and degeneration of central nervous system tissue.
Subacute doses administered orally to laboratory animals produced some
decrease in growth and degeneration of the testes. Chronic studies in
animals showed similar effects to those found in acute and subacute
studies, but to a much lower degree. The same organs were enlarged,
but pathological changes were not usually detected.
A recent study of several phthalic esters produced suggestive but not
conclusive evidence that dimethyl and diethyl phthalates have a cancer
-------
liability. Only four of the six priority pollutant esters were
included in the study. Phthalate esters do biconcentrate in fish.
The factors, weighted for relative consumption oi various aquatic and
marine food groups, are used to calculate ambient water quality
criteria for four phthalate esters. The values are included in the
discussion of the specific esters.
Studies of toxicity of phthalate esters in freshwater and salt water
organisms are scarce. Available data show that adverse effects on
aquatic life occur at phthalate ester concentrations as low as 0.003
mg/1.
The behavior of phthalate esters in POTW has not been studied.
However, tfe biochemical oxidation of many of the organic priority
pollutants has been investigated in laboratory-scale studies at
concentrations higher than would normally be expected in municipal
wastewater. Three of the phthalate esters were studied.
Bis(2-ethylhexyl) phthalate was found to be degraded slightly or not
at all and its removal by biological treatment in a POTW is expected
to be slight or zero. Di-n-butyl phthalate and diethyl phthalate were
degraded to a moderate degree and it is expected that they will be
biochemically oxidized to a lesser extent than domestic sewage by
biological treatment in POTW. Based on these data and other
observations relating molecular structure to ease of biochemical
degradation of other organic pollutants, it is expected that butyl
benzyl phthalate and dimethyl phthalate will be biochemically oxidized
to a lesser extent than domestic sewage by biological treatment in
POTW. On the same basis, it is expected that di-n-octyl phthalate
will not be biochemically oxidized to a significant extent by
biological treatment in POTW. An EPA study of seven POTW revealed
that for all but di-n-octyl phthalate, which was not studied, removals
ranged frox 62 to 87 percent.
No information was found on possible interference with POTW operation
or the possible effects on sludge by the phthalate esters. The water
insoluble phthalate esters - butylbenzyl and di-n-octyl phthalate
would tend to remain in sludge, whereas the other four toxic pollutant
phthalate esters with water solubilities ranging from 50 mg/1 to 4.5
mg/1 would probably pass through into the POTW effluent.
Bis (2-ethylhexyl) phthalate'66). In addition to the general remarks
and discussion on phthalate esters, specific information on
bis<2-ethylhexyl> phthalate is provided. Little information is
available about the physical properties of bis(2-ethylhexyl)
phthalate. It is a liquid boiling at 387°C at 5mm Hg and is insoluble
in water. Its formula is C4H« ''COOCBH, 7) ?. This priority pollutant
constitutes about one third of the phthalate ester production in the
U.S. It is coxTionly referred to as dioctyl phthalate, or OOP, in the
plastics industry where it is the most extensively used compound for
the plasticization of polyvinyl chloride (PVC}. Bis(2-ethylhexyl)
phthalate has been approved by the FDA for use in plastics in contact
with food. Therefore, it ray be found in wastewaters coming in
contact with discarded plastic food wrappers as well as the PVC films
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and shapes normally found in industrial plants. This priority
pollutant is also a commonly used organic diffusion pump oil where its
low vapor pressure is an advantage.
For the protection of human health from the toxic properties of
bis(2-ethylhexyl) phthalate ingested through water and through
contaminated aquatic organisms, the ambient water criterion is
determined to be 15 mg/1. If contaminated aquatic organisms alone are
consumed, excluding the consumption of water, the ambient water
criteria is determined to be 50 mg/1.
Although the behavior of bis(2-ethylhexyl) phthalate in POTW has not
been studied, biochemical oxidation of this priority pollutant has
been studied on a laboratory scale at concentrations higher than would
normally be expected in municipal wastewater. In fresh water with a
nonacclimated seed culture no biochemical oxidation was observed after
5, 10, and 20 days. However, with an acclimated seed culture,
biological oxidation occurred to the extents of 13, 0, 6, and 23 of
theoretical after 5, 10, 15 and 20 days, respectively.
Eis(2-ethylhexyl) phthalate concentrations were 3 to 10 mg/1. Little
or no removal of bis(2-ethylhexyl) phthalate by biological treatment
in POTW is expected.
Butyl benzyl phthalate(67). In addition to the general remarks and
discussion on phthalate esters, specific informc«-ion on butyl benzyl
phthalate is provided. No information was found on the physical
properties of this compound.
Butyl benzyl phthalate is used as a plasticizer for PVC. Two special
applications differentiate it from other phthalate esters. It is
approved by the U.S. FDA for food contact in wrappers and containers;
and it is the industry standard for plasticization of vinyl flooring
because it provides stain resistance.
No ambient water criterion is proposed for butyl benzyl phthalate.
Butyl benzyl phthalate removal in POTWs is discussed
discussion of phthalate esters.
in the general
Di-n-butyl phthalate (68). In addition to the general remarks and
discussion on phthalate esters, specific information on di-n-butyl
phthalate (DBF) is provided. DBP is a colorless, oily liquid, boiling
at 34C°C. Its water solubility at room temperature is reported to be
0.4 g/J and 4.5g/l in two different chemistry handbooks. The formula
for DBP, C«H4(CnoC4H»), is the same as for its isomer, di-isobutyl
phthalate. DCP production is one to two percent of total U.S.
phthalate ester production.
Dibutyl phthalate is used to a limited extent as a plasticizer for
polyvinyichloride (PVC). It is not approved for contact with fc-)d.
It is used in liquid lipsticks and as a diluent for polysulfide dental
impression materials. DBP is used as a plasticizer for nitrocellulose
in making gun powder, and as a fuel in sol'd propellants for rockets.
I •'?:
•5
i
j
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Further uses are insecticides, safety glass manufacture, textile
lubricating aoents, printing inks, adhesives, paper coatings and resin
solvents.
For protection of human health from the toxic properties of dibutyl
phthalate ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determined to be 34 mg/1.
If contaminated aquatic organisms alone are consumed, excluding the
consumption of water, the ambient water criterion is 154 mg/1.
Although the behavior of di-n-butyl phthalate in POTW has not been
studied, biochemical oxidation of this toxic pollutant has been
studied on a laboratory scale at concentrations higher than would
normally be expected in municipal wastewater. Biochcn.ical oxidation
of 35, 43, and 45 percent of theoretical oxidation were obtained after
*jt 10, and 20 days, respectively, using sewage microorganisms as an
unacclimated seed culture. Based on these data, it is expected that
di-n-butyl phthalate will be biochemically oxidized to a lesser extent
than domestic sewage by biological treatment in POTWs.
Biological treatment in POTW
phthalate to a moderate degree.
is expected to remove di-n-butyl
Di-n-octyl phthalate(69). In addition to the general remarks and
discussion on phthalate esters, specific information on di-n-octyl
phthalate is provided. Di-n-octyl phthalate is not to be confused
with the isomeric bis(2-ethylhexyl) phthalate which is commonly
referred to in the plastics industry as OOP. Di-n-octyl phthalate is
a liquid which boils at 220°C at 5 mn, Hg. It is insoluble in water.
Its molecular formula is C«H4(COOCeH,7),. Its production constitutes
about one percent of all phthalate ester production in the U.S.
Industrially, di-n-octyl
chloride (PVC) resins.
phthalate is used to plasticize polyvinyl
No ambient water criterion is proposed for di-n-octyl phthalate.
Biological treatment in POTW is expected to lead to little cr no
removal of di-n-octyl phthala.e.
Diethyl phthalate (70). In addition to
discussion on phthalate esters, specific
phthalate ib provided. Diethyl phthalate,
liquid boiling at 296°C, and is insoluble in
tor-nula is C«H4 (COOC,HS),. Production
constitutes
U.S.
the general remarks and
information on diethyl
or DEP, is a colorless
water. Its molecular
of diethyl phthalate
about 1.5 percent of phthalate ester production in the
Diethyl phthalate is approved for use in plastic food containers by
the U.S. FDA. In addition to its use as a polyvinylchloride (PVC)
plasticizer, DEP is used to plasticize cellulose nitrate for qun
powder, to dilute polysulfide dental impression T.aterials, and as an
accelerator for dying triacetate fibers. An additional use which
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would contribute to its wide distribution in the environment is as an
approved special denaturant for ethyl alcohol. The alcohol-containing
products for which DEP is an approved denaturant include a wide range
of personal care items such as bath preparations, bay rum, colognes,
hair preparations, face and hand creams, perfumes and toilet soaps.
Additionally, this denaturant is approved for use in biocides,
cleaning solutions, disinfectants, insecticides, fungicides, and room
deodorants which have ethyl alcohol as part of the formulation. It is
expected, therefore, that people and buildings would have some surface
loading of this priority pollutant which would find its way into raw
wastewaters.
For the protection of human health from the toxic properties of
diethyl phthalate ingested through water and through contaminated
aquatic organisms, the ambient water criterion is determined to be
350 mg/1. If contaminated aquatic organisms alone are consumed,
excluding the consumption of water, the ambient water criterion'is
1800 mg/1.
Although the behavior of diethylphthalate in. POTW has not been
studied, biochemical oxidation of this toxic pollutant has been
studied on a laboratory scale at concentrations higher than would
normally be expected in municipal wastewater. Biochemical oxidation
of 79, 84, and 89 percent of theoretical was observed after 5, 5, and
20 clays, respectively. Based on these data it is expected that
diethyl phthalate will be biochemically oxidized to a lesser extent
than domestic sewage by biological treatment in POTWs.
Dimethyl phthalate (71). In addition to the general remarks and dis-
cussion on phthalate esters, specific information on dimethyl
phthalate (DMP) is provided. DMP has the lowest molecular weight of
the phthalate esters - M.W. « 194 compared to M.W. of 391 for
bis-'2-et.hylhexyl jphthalate. DMP has a boiling point of 282°C. It is
a colorless liquid, soluble in water to the extent of 5 mg/1. Its
molecular formula is C4H4(COCCH,),.
Dimethyl phthalate production in the U.S. is just under one percent of
total phthalate ester production. DMP is used to some extent as a
plasticizer in cellulosics. However, its principle specific use is
for dispersion of polyvinylidene fluoride (PVDF). PVDF is resistant
to most chemicals and finds use as electrical insulation, chemical
process equipment (particularly pipe), and as a base for long-life
finishes for exterior metal siding. Coil coating techniques are used
to apply PVDF dispersions to aluminum or galvanized steel siding.
For the protection of human health from the toxic properties of
dimethyl phthalate ingested through water and through contaminated
aquaLic organisms, the ambient water criterion is determined to be 313
mg/1. If contaminated aquatic organises alone are consumed, excluding
the consumption of water, the ambient water criterion is 280C ir.g/1.
Based on limited data and observations relating molecular structure to
ease of biochemical degradation of other organic pollutants, it is
-------
expected that dimethyl phthalate will be biochemically oxidized to a
lesser extent than domestic sewage of biological treatment in POTWs.
Polynuclear Aromatic Hydrocarbons(72-84). The polynuclear aromatic
hydrocarbons (PAH) selected as toxic pollutants are a group of 13
compounds consisting of substituted and unsubstituted polycyclic
aromatic rings. The general class of PAH includes hetrocyclics, but
none of those were selected as toxic pollutants. PAH are formed as
the result of incomplete combustion when organic compounds are burned
with insufficient oxygen. PAH are found in coke oven emissions,
vehicular emissions, and volatile products of oil and gas burning.
The compounds chosen as priority pollutants are listed with the
structural formula and melting point (m.p.) for each. All are
insoluble in water.
72 Benzo(a)anthrancene (1,2-benzanthracene)
m.p. 162°C
73 3enzo(a)pyrene (3,4-benzopyrene)
m.p. 176°C
74 3,4-Benzofluoranthene
m.p. 168°C
75 Benzo(k)fluoranthene {11,12-benzofluoranthene)
m.p. 217<>C
76 Chrysene (1,2-benzphenanthrene)
m.p. 2550C
77 Acenaphthylene
HC-CH
m.p. 92°C
78 Anthracene
m.p. 216°C
79 Benzo(ghi)perylene (1,12-benzoperylene)
m.p. not reported
80 Fluorene (alpha-diphenylenemethane)
m.p. 116°C
-------
81 Phenanthrene
m.p. 101«C
82 Dibenzo(a,h)anthracene (1,2.5,6-dibenzoanthracene)
m.p. 269<>C
83 Indenod,2,3-cd)pyrene (2,3-o-phenyleneperylene)
84 Pyrene
m.p. not available
m.p. 156°C
Some of these priority pollutants have commercial or industrial uses.
Benzo(a)anthracene, benzo(a)pyrene, chrysene, anthracene,
dtbenzo(a,h)anthracene, and pyrene are all used as antioxidants.
Chrysene, acenaphthylene, anthracene, fluorene, phenanthrene, and
pyrene are all used for synthesis of dyestuffs or other organic
chemicals. 3,4-Benzofluoranthrene, benzo'k)fluoranthene,
benzo(ghi )perylene, and indeno (1,2,3-cd)pyrene have no known
industrial uses, according to the results of a recent literature
search.
Several of the PAH toxic pollutants are found in smoked meats, in
smoke flavoring mixtures, in vegetable oils, and in coffee. They are
found in soils and sediments in river beds. Consequently, they are
also found in many drinking water supplies. The wide distribution of
these pollutants in complex mixtures with the many other PAHs which
have not been designated as toxic pollutants results in exposures by
humans that cannot be associated with specific individual compounds.
The screening and verification analysis procedures used for the
organic toxic pollutants are based on gas chromatography (GO. Three
pairs of the PAH have identical elution times on the column specified
in the protocol, which means that the pollutants of the pair are not
differentiated. For these three pairs [anthracene !78) - phenanthrene
(81); 3,4-benzofluoranthene (74' - benzolk}fluoranthene (75); and
benzofa(anthracene (72) - chrysene (760 results are obtained and
reported as "either-or." Either both are present in the combined
concentration reported, or one is present in the concentration
reported. When detections below reportable limits are recorded no
further analysis is required. For samples where the concentrations of
coeluting pairs have a significant value, additional analyses are
conducted, using different procedures that resolve the particular
pair.
-------
There are no studies to document the possible carcinogenic risks to
humans by direct ingestion. Air pollution studies indicate an excess
of lung cancer mortality among workers exposed to large amounts of PAH
containing materials such as coal gas, tars, and coke-oven emissions.
However, no definite proof exists that the PAH present in these
materials are responsible for the cancers observed.
Animal studies have demonstrated the toxicity of PAH by oral and
deriral administration. The carcinogenicity of PAH has been traced to
formation of PAH metabolites which, in turn, lead to tumor formation.
Because the levels of PAH which induce cancer are very low, little
work has been done on other health hazards resulting from exposure.
It has been established in animal studies that tissue damage and
systemic toxicity can result from exposure to noncarcinogenic PAH
compounds.
Because there were no studies available regarding chronic oral
exposures to PAH mixtures, proposed water quality criteria were
derived using d?,ta on exposure to a single compound. Two studies were
selected, one involving benzofa)pyrene ingestion and one involving
dibenzo(a,hJantnracene ingestion. Both are known animal carcinogens.
For the maximum protection of human health from the potential car-
cinogenic effects of exposure to polynuclear aromatic hydro- carbons
(PAH; through ingestion of water and contaminated aquatic organisms,
the ambient water concentration is zero. Concentrations of PAH
estimated to result in additional lifetime cancer risk of 10~7, JO-*,
and 10-* are 2.8 x 10~7 mg/1, 2.8 x aO~* mg/1 and 2.8 x 10-» mg/1,
respectively. If contaminated aquatic organisms alone are consumed,
excluding the consumption of water, the water concentration should be
less than 3.11 x 10~« mg/1 to keep the increased lifetime cancer risk
below 10-*. Available data show the adverse effects on aquatic life
occur at concentrations higher than those cited for human health r~.sk.
The behavior of PAH in POTW has received only a limited amount of
study. It is reported that up to 90 percent of PAH entering a POTW
will be retained in the sludge generated by conventional sewage
treatment processes. Some of the PAH can inhibit bacterial growth
when they are present at concentrations as low as 0.018 mg/1.
Biological treatment in activated sludge units has been shown to
reduce the concentration of phenanthrene and anthracene to some
extent. However, a study of biochemcial oxidation of fluorene on a
laboratory scale showed no degradation after 5, 10, and 20 days. On
the basis of that study and studies of other organic priority
pollutants, some general observations were made relating molecular
structure to ease of degradation. Those observations lead to the
conclusion that the 13 PAH selected to represent that group as toxic
pollutants will be removed only slightly or not at ail by biological
treatment methods in POTW. Based on their water insolubility and
tendency to attach to sediment particles very little pass through of
PAH to POTW effluent is expected.
-------
No data are available at this time to support any conclusions about
contamination of land by PAH on which sewage sludge containing PAH is
spread.
Tetrachlcroethylenef85). Tetrachloroethylene (CC1,CC1,), also called
perchloroethylene and PCE, is a colorless nonflammable liquid produced
mainly by two methods - chlorination and pyrolysis of ethane and
propane, and oxychlorination of dichloroethane. U.S. annual
production exceeds 300,000 tons. PCE boils at 121°C and has a vapor
pressure of 19 mm Hg at 2C°C. It is insoluble in water but soluble in
organic solvents.
Approximately two-thirds of the U.S. production of PCE is used for dry
cleaning. Textile processing and metal degreasing, in equal amounts
consume about one-quarter of the U.S. production.
The principal toxic effect of PCE on humans is central nervous system
depression when the compound is inhaled. Headache, fatigue,
sleepiness, dizziness and sensations of intoxication are reported.
Severity of effects increases with vapor concentration. High
integrated exposure (concentration times duration) produces kidney and
liver damage. Very limited data on PCE ingested by laboratory animals
indicate liver damage occurs when PCE is administered by that route.
PCE tends to distribute to fat in mammalian bodies.
One report found in the literature
that PCE is teratogenic. PCE
carcinogen in B6C3-FI mice.
suggests, but does rot conclude,
has been demonstrated to be a liver
For the maximum protection of human health from the potential
carcinogenic effects of exposure to tetrachloroethylene through
ingestion of water and contaminated aquatic organisms, the ambient
water concentration is zero. Concentrations of tetrachloroethylene
estimated to result in additional lifetime cancer risk levels of 10~7,
1C-*, and iC-s are 8 x 10-* ma/], 8 x 10-* mg/1, and 8 x 10-* mg/1
respectively. If contaminated aquatic organisms alone are consumed,
excluding the consumption of water, the water concentration should be
less than 0.088 mg/1 to keep the increased lifetime cancer risk below
10~5. Available data show that adverse effects on aquatic life occur
at concentrations higher than those cited for human health risks.
Few data were found regarding the behavior of PCE in POTW. Many of
the oraanic toxic pollutants have been investigated, at least in
laboratory scale studies, at concentrations higher than those expected
to be contained by most municipal wastewaters. General observations
have been developed relating molecular structure to ease of
degradation for all of the organic toxic pollutants. Based on study
of the limited data, it is expected that PCE will be biochemically
oxidized to a lesser extent than domestic sewage
treatment in POTW. An EPA study of seven POTW revealed
by biological
removals of 40
to 100 percent
from 1 x 10-J
Sludge concentrations of tetrachloroethylene ranged
to 1 .6 mg/1
>ome PCE is expected to be volatilized in
-------
aerobic treatment processes and little, if any, is expected to pass
through into the effluent from the POTW.
Toluene(86). Toluene is a clear, colorless liquid with a benzene like
odor. It is a naturally occuring compound derived primarily from
petroleum or petrochemical processes. Some toluene is obtained from
the manufacture of metallurgical coke. Toluene is also referred to as
totuol, methylbenzene, methacide, and phenymethane. It is an aromatic
hydrocarbon with the formula C«H5CH,. It boils at 111°C and has a
vapor pressure of 30 mm Hg at room temperature. The water solubility
of toluene is 535 mg/1, and it is miscible with a variety of organic
solvents. Annual production of toluene in the U.S. is greater than 2
million metric tens. Approximately two-thirds of the toluene is
converted to benzene and the remaining 30 percent is divided
approximately equally into chemical manufacture, and use as a paint
solvent and aviation gasoline additive. An estimated 5,000 metric
tons is discharged to the environment annually as a constituent in
wastewater.
Most data on the effects of toluene in human and other mammals have
been based on inhalation exposure or dermal contact studies. There
appear to be no reports of oral administration of toluene to human
subjects. A long term toxicity study on female rats revealed no
adverse effects on growth, mortality, appearance and behavior, organ
to body weight ratios, blood-urea nitrogen levels, bone marrow counts,
peripheral blood counts, or morphology of major organs. The effects
of inhaled tcluene on the central nervous system, both at high and low
concentrators, have been studied in humans and animals. However,
ingested toluene is expected to be handled differently by the body
because it is aosorbed more slowly and must first pass through the
liver before reaching the nervous system. Toluene is extensively and
rapidly metabolized in the liver. One of the principal metabolic
products of toluene is benzoic acid, which itself seems to have little
potential to proJuce tissue injury.
Toluene does not appear to be teratogenic in laboratory animals or
man. Nor is there any conclusive evidence that toluene is mutagenic.
Toluene has .>ot been demonstrated to be positive in any in vitro
mutagenicity or c<*rcinogenicity bioassay system, nor to be
carcinogenic in animals or man.
Toluene has been found in fish caught in harbor waters in the vicinity
of petroleum and petrochemical plants. Bioconcentration studies have
not been conducted, but bioconcentration factors have been calculated
on the basis of the octanol-water partition coefficient.
For the protection of human health from the toxic properties of
toluene ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determined to be 14.3 mg/1.
If contaminated aquatic organisms alone are consumed, excluding the
consumption of water, the axbient water quality criterion is 424 mg/1.
Available data show that adverse effects on aquatic life occur at
concentrations as low as 5 mg/1.
-V
-------
Acute toxicity tests have been conducted with toluene and a variety of
freshwater fish and Daphnla magna. The latter appears to be
significantly more resistant than fish. No test results have been
reported for the chronic effects of toluene on freshwater fish or
invertebrate species.
Only one study of toluene behavior in POTW is available. However, the
biochemical oxidation of many of the toxic pollutants has been
investigated in laboratory scale studies at con- centrations greater
than those expected to be contained by most municipal wastewaters. At
toluene concentrations ranging from 3 to' 250 mg/1 biochemical
oxidation proceeded to fifty percent of theroetical or greater. The
time period varied from a few hours to 20 days depending on whether or
not the seed culture was acclimated. Phenol adapted acclimated seed
cultures gave the most rapid and extensive biochemical oxidation.
Based on study of the limited data, it is expected that toluene will
be biochemically oxidized to a lesser extent than domestic sewage by
biological treatment in POTW. The volatility and relatively low water
solubility of toluene lead to the expectation that aeration processes
will remove significant quantities of toluene from the POTW. The EPA
studied toluene removal in seven POTW. The removals ranged from 40 to
100 percent. Sludge concentrations of toluene ranged from 54 x 10~J
to 1.85 mg/1.
«
Antimonyt114). Antimony (chemical name - stibium, symbol Sb)
classified as a nonmetal or metalloid, is a silvery white , brittle,
crystalline solid. Antimony is found in small ore bodies throughout
the world. Principal ores are oxides of mixed antimony valences, and
an oxysulfide ore. Complex ores with metals are important because the
antimony is recovered as a by-product. Antimony melts at 631°C, and
is a poor conductor of electricity and heat.
Annual U.S. consumption of primary antimony ranges from 10,000 to
20,000 tons. About half is consumed in metal products - mostly
antimonial lead for lead acid storage batteries, and about half in non
- metal products. A principal compound is antimony trioxide which is
used as a flame retardant in fabrics, and as an opacifier in glass,
ceramincs, and enamels. Several antimony compounds are used as
catalysts in organic chemicals synthesis, as fluorinating agents (the
antimony fluoride), as pigments, and in fireworks. Semiconductor
applications are economically significant.
Essentially no information on antimony - induced human health effects
has been derived from community epidemiolocy studies. The available
data are in literature relating effects observed with therapeutic or
medicinal uses of antimony compounds and industrial exposure studies.
Large therapeutic doses of antimonial compounds, usually used to treat
schistisoxiasis have caused severe nausea, vomiting, convulsions,
irregular heart action, liver damage, and skin rashes. Studies of
acute industrial antimony poisoning have revealed loss of appetite,
diarrhea, headache, and dizziness in addition to '.he symptoms found in
studies of therapeutic doses of antimony.
-------
For the protection of human health from the toxic properties of
antimony ingested through water and through contaminated aquatic
organisms the ambient water criterion is determined to be 0.146 mg/1.
If contaminated aquatic organisms alone are consumed, excluding the
consumption of water, the ambient water criterion is determined to be
45 mg/1. Available data show that adverse effects on aquatic life
occur at concentrations higher than those cited for human health
risks.
Very little information is available regarding the behavior of
antimony in POTW. The limited soluoility of most antimony compounds
expected in POTW, i.e. the oxides and sulfides, suggests that at least
part of the antimony entering a POTW will be precipitated and
incorporated into the sludge. However, some antimony is expected to
remain dissolved and pass through the POTW into >:he effluent.
Antimony compounds remaining in the sludge under anaerobic conditions
may be connected to stibine (SbH,), a very soluble and very toxic
compound. There are no data to show antimony inhibits any POTW
processes. Antimony is not known to be essential to the growth of
plants, and has been reported to be moderately toxic. Therefore,
sludge containing large amounts of antimony could be detrimental to
plants if it is applied in large amounts to cropland.
Arsenic(\\5). Arsenic (chemical symbol As), is classified as a
nonmetal or metalloid. Elemental arsenic normally exists in the
alpha-crystalline metallic form which is Jteel gray and brittle, and
in the beta form which is dark gray and amorphous. Arsenic sublimes
at 615°C. Arsenic is widely distributed throughout the world in a
large number of minerals. The most important commercial source of
arsenic is as a by-product from treatment of copper, lead, cobalt, and
?;c.-ld ores. Arsenic is usually marketed as the trioxide (As,0s).
Annual U.S. production of the trioxide approaches 40,000 tons.
The principal use of arsenic is in agricultural chemicals (herbicides)
for controlling weeds in cotton fields. Arsenicals have various
applications in medicinal and veterinary use, as wood preservatives,
and in semiconductors.
The effects of arsenic in humans were known by the ancient Greeks and
Romans. The principal toxic effects are gastro.r.testinal
disturbances. Breakdown of red blood cells occurs. Symptoms of acute
poisoning include vomiting, diarrhea, abdominal pain, lassitude,
dizziness, and headache. Lonqer exposure produced dry, falling hair,
brittle. loose nails, eczema; and exfoliation. Arsenicals also
exhibit teratoqenic and mutagenic effects in humans. Oral
adr.imstration of arsenic coxpounds has been associated clinically
with skin cancer for nearly a hundred years. Since 1888 numerous
studies have linked occupational exposure to, and therapeutic
admmstration of arsenic compounds to increased incidence of
respiratory and skin cancer.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to arsenic through ingestion of water
-------
and contaminated aquatic organisms, the ambient water concentration is
zero. Concentrations of arsenic estimated to result in additional
lifetime cancer risk levels of 10-', 10-*, and 10-* are 2.2 x 10~r
mg/1, 2.2 x 10-* mg/1, and 2.2 x 10"» mg/1, respectively. If
contaminated aquatic organisms alone are consumed, excluding the
consumption of water, the water concentration should be less than 2.7
x 10"* mg/1 to keep the increased lifetime cancer risk below J0~9.
Available data show that adverse effects on aquatic life occur at
concentrations higher than those cited for human health risks.
A few studies have been made regarding the behavior of arsenic in
POTW. One EPA survey of 9 POTW reported influent concentrations
ranging from 0.0005 to 0.693 mg/1; effluents from 3 POTW having
biological treatment contained 0.0004 - 0.01 mg/1; 2 POTW showed
arsenic removal efficiencies of 50 and 71 percent in biological
treatment. Inhibition of treatment processes by sodium arsenate is
reported to occur at 0.1 mg/1 in activated sludge, and 1.6 mg/1 in
anaerobic digestion processes. In another study based on data from 60
POTW, arsenic in sludge ranged from 1.6 to 65.6 mg/kg and the median
value was 7.8 mg/kg. Arsenic in sludge spread on cropland may be
taken up by plants grown on that land. Edible paints can take up
arsenic, but normally their growth is inhibited before the paints are
ready for harvest.
Cadmium(118). Cadmium is a relatively rare metallic element that is
seldom found in sufficient quantities in a pure state to warrant
mining or extraction from the earth's surface. It is found in trace
amounts of about 1 ppm throughout the earth's crust. Cadmium is,
however, a valuable by-product of zinc production.
Cadmium is used primarily as an electroplated metal, and is foun^ as
an impurity in the secondary refining of zinc, lead, and copper.
Cadmium is an extremely dangerous cumulative toxicant, causing
progressive chronic poisoning in mammals, fish, and probably other
organisms. The metal is not excreted.
Toxic effects of cadmium on man have been reported from throughout the
world. Cadmium may be a factor in the development of such human
pathological conditions as kidney disease, testicular tumors,
hypertension, arteriosclerosis, growth inhibition, chronic disease of
old age, and cancer. Cadmium ii. normally ingested by humans through
food and water as well as by breathing air containinaced by cadmium
dust. Cadmium is cumulative in the liver, kidney, pancreas, and
thyroid of humans and other animals. A severe bone and kidney
syndrome known as itai-itai disease has been documented in Japan as
caused by cadmium ingestion via drinking water and contarinattd
irrigation water. Ingestion of as little as 0.6 mg/day has produced
the disease. Cadmium acts synergistically with other metals. Copper
and zinc substantially increase its toxicity.
Cadmium is concentrated by marine organisms, particularly irollusks,
which accumulate cadmium in calcareous tissues and in the viscera. A
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concentration factor of 1000 for cadmium in fish muscle has been
reported, as have concentration factors of 3000 in marine plants and
up to 29,600 in certain marine animals. The eggs and larvae of fish
are apparently more sensitive than adult fish to poisoning by cadmium,
and crustaceans appear to be more sensitive than fish eggs and larvae.
For the protection of human health from the toxic properties of
cadmium ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determined to be 0.010 sg/1.
Available data show that adverse effects on aquatic life occur at
concentrations in the same range as those cited for human health, and
they are highly dependent on water hardness.
Cadmium is not destroyed when it is introduced into a POTW, and will
either pass through to the POTW effluent or be incorporated into the
POTW sludge. In addition, it can interfere with the POTW treatment
process.
In a study of 18? POTW, 75 percent of the primary plants, 57 percent
of the trickling filter plants, 66 percent of the activated sludge
plants and 62 percent o* the biological plants allowed over 90 percent
of the influent cadmium to pass thorugh to the POTW effluent. Only 2
of the 189 POTW allowed less than ?0 percent pass-through, and none
less than 10 percent pass-through. POTW effluent concentrations
ranged from 0.001 to 1.97 mg/1 (mean 0.028 mg/1, standard deviation
0.167 mg/1).
Cadmium not passed through the POTW will be retained in the sludge
where it is likely to build up in concentration. Cadmium
contamination of sewage sludge limits its use on land since it
increases the level of cadmium in the soil. Data show that cadxium
can be incorporated into crops, including vegetables and grains, from
contaminated soils. Since the crops themselves show no adverse
effects from soils with levels up to 100 mg/kg cadmium, these
contaminated crops could have a significant impact on human health.
Two Federal agencies have already recognized the potential adverse
human health effects posed by the use of sludge on cropland. The FDA
recommends that sludge containing over 30 mg/kg of cadmium should not
be used on agricultural land. Sewage sludge contains 3 to 3CC ir.g/kg
(dry basis) of cadmium mean - 10 mg/kg; median • 16 mg/kg. The L'SDA
also recommends placing limits on the total cadmium from sludge that
may be applied to land.
ChroT.tunr' 1 19) . Chromium is an elemental metal usually found as a v-
chrorr.ite iFeO»Cr,03). The metal is normally produced by reducing the (
oxidt with aluminum. A significant proportion of the chromium used is
in the form of compounds such as sodium dichromate (Na,CrC«-, and
chromic acid (CrO,) - both are hexavalent chromium compounds.
Chromium is found as an alloying component of many steels and its
coTpounds are used in electroplating baths, and as corrosion
inhibitors for closed water circulation systems.
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The two chromium forms most frequently found in industry wastewaters
are hexavalent and trivalent chromium. Hexavalaent chromium is the
form used for metal treatments. Some of it is reduced to trivalent
chromium as part of the process reaction. The raw wastewater
containing both valence states is usually treated first to reduce
remaining hexavalent to trivalent chromium, and second to precipitate
the trivalent form as the hydroxide. The hexavalent form is not
removed by lime treatment.
Chromium, in its various valence states, is hazardous to man. It can
produce lung tumors when inhaled, and induces skin sensitizations.
Large doses of chromates have corrosive effects on the intestinal
tract and can cause inflammation of the kidneys. Hexavalent chromium
is a known human carcinogen. Levels of chromate ions that show no
effect in man appear to be so low as to prohibit determination, to
date.
The toxicity of chromium salts to fxsh and other aquatic life varies
widely with the species, temperature, pH, valence of the chromium, and
synergistic or antagonistic effects, especially the effect of water
hardness. Studies have shown that trivalent chromium is more toxic fc
fish of some types than is hexavalent chromium. Hexavalent chromium
retards growth of one fish species at 0.0002 mg/1. Fish food
organisms and other lower forms of aquatic life are extremely
sensitive to chromium. Therefore, both hexavalent an^ trivalent
chromium must be considered harmful to particular fish or organisms.
For the protection of human health from the toxic properties of
chromium (except hexavalent chromium) ingested through water and
contaminated aquatic organisms, the ambient water criterion is 0.050
mg/1. For the maximum protection of hurran health from the potential
carcinogenic effects of exposure to hexavalent chromium through
ingestion of water and contaminated aquatic organisms, the ambient
water concentration is zero. The estimated levels which would result
in increased lifetime cancer risks of 10-*, 10-*, and 10~» are 7.4 x
10-» ng/1, 7.4 x 10~7 mg/1, and 7.4 x 10-* mg/1 respectively. If
contaminated aquatic organisms alone are consumed, excluding the
consumption of water, the water concentration should be less than 1.5
x 10-» mg/1 to keet the increased lifetime cancer risk below 10~».
Chromium is not destroyed when treated by POTW (although the oxidation
state may channe), and will either pass through to the POTW effluent
or be incorporated into the POTW sludoe. Both oxidation states can
cause POTW treatment inhibition and can also limit the usefuleness of
municipal sludge.
Influent, concentrations cf chromium to POTW facilities have been
observed by EPA to range froir 0.005 to 14.0 mg/1, with a median
concentration of 0.1 mg/1. The efficiencies for removal of chror.iuT,
by Vne activated sludge process can vary greatly, depending on
chromum concentration in the influent, and other operating conditions
at tne POTW. Chelation of chroTii-m by organic matter and dissolution
.-a
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\
due to the presence of carbonates can
predicted behavior in treatment systems.
cause deviations from the
The systematic presence of chromium compounds will halt nitrification
in a POTW for short periods, and most of the chromium will be retained
in the sludge solids. Hexavalent chromium has been reported to
severely affect the nitrification process, but trivalent chromium has
litte or no toxicity to activated sludge, except at high
concentrations. The presence of iron, copper, and low pH will
increase the toxicity of chromium in a POTW by releasing the chromium
into solution to be ingested by microorganirms in the POTW.
The amount of chromium which passes through to the POTW effluent
depends on the type of treatment processes used by the POTW. In a
study of 240 POTWs 56 percent of the primary plants allowed more than
80 percent pass through to POTW effluent. More advanced treatment
results in less pass-through. POTK effluent concentrations ranged
from 0.003 to 3.2 mg/1 total chromium (mean • 0.197, standard
deviation » 0.48), and from 0.002 to 0.1 mg/1 hexavalent chromium
(mean » 0.017, standard deviation » 0.020).
Chromium not passed through the POTW will be retained in the sludge,
where it is likely to build up in concentration. Sludge
concentrations of total chromium of over 20,000 mg/kg (dry basis) have
been observed. Disposal of sludges containing very high
concentrations of trivalent chromium can potentially cause problems in
uncontrollable landfills. Incineration, or similar destructive
oxidation processes can produce hexavalent chromium from lower valance
states. Hexavalent chromium is potentially more toxic than trivalent
chromium. In cases where high rates of chrome sludge application on
land are used, distinct growth inhibition and plant tissue uptake have
been noted.
Pretreatment of discharges substantially reduces the concentration of
chromium in sludge. In Buffalo, New York, pretreatment of
electroplating waste resulted in a decrease in chroTaum concentrations
in POTW sludge from 2,510 to 1,040 mg/kg. A similar reduction
occurred in in Grand Rapids, Michigan POTW where the chromium
concentration in sludge decreased from 11,000 to 2,700 mg/kg when
pretreatment was made a requirement.
Copper M 20). Copper is a metallic element that sometimes is found
tree, as the native metal, and is also found in minerals such as
cuprite
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gastroenteritis, with nausea and intestinal irritations, at relatively
low dosages. The limiting factor in domestic water supplies is taste.
To prevent this adverse organoleptic effect of copper in water, a
criterion of 1 mg/1 has been established.
The toxicity of copper to aquatic organisms varies significantly, not
only with the species, but also with the physical and chemical
characteristics of the water, including temperature, hardness,
turbidity, and carbon dioxide content. In hard water, the touicity of
copper salts may be reduced by the precipitation of copper carbonate
or other insoluble compounds. The sulfates of copper and zinc, and of
copper and calcium are synergistic in their toxic effect on fish.
Relatively high concentrations of copper may be tolerated by adult
fish for short periods of time; the critical effect of copper appears
to be its higher toxicity to young or juvenile fish. Concentrations
of 0.02 to 0.031 mg/1 have proven fatal to some common fish species.
In general the salmonoids are very sensitive and the sunfishes are
less sensitive to copper.
The recommended criterion to protect saltwater aquatic life is
0.00097 mg/1 as a 24-hour average, and 0.016 mg/1 maximum
concentration.
Copper salts cause undesirable color reactions in the food industry
and cause pitting when deposited or. -erne other metals such as aluminum
and galvanized steel. To control undesirable taste and odor quality
of ambient water due to the organoleptic properties of copper, the
estimated level is 1.0 mg/1. For total recoverable copper the
criterion to protect freshwater aquatic life is 5 6 x 10-* mg/1 as a
24 hour average.
Irrigation water containing more than minute quantities of copper can
be detrimental to certain crops. Copper appears in all soils, and its
concentration ranges from 10 to 80 ppir. In soils, copper occurs in
association with hydrous oxides of manganese and iron, and also as
soluble and insoluble complexes with organic matter. Copper is
essential to the life of plants, and the normal range of concentration
in plant tissue is from 5 to 20 ppm. Copper concentrations in plants
normally do not build up to high levels when toxicity occurs. For
example, the concentrations of copper in snapbean leaves and pods was
less than 50 and 20 mg/kg, respectively, under conditions of severe
copper toxicity. Even under conditions of copper toxicity, most of
the excess copper accumulates in the roots; very little is moved to
the aerial part of the plant.
Copper is not destroyed when treated by a POTW, and will either pass
through to the POTW effluent or be retained in the POTW sludge. It
can interfere with the POTW treatment processes and can limit the
usefulness of municipal sludge.
The influent concentration of copper to POTW facilities has been
observed oy the EPA to range from 0.01 to 1.97 mg/1, with a median
*%
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concentration of 0.12 mg/1. The copper that is removed from the
influent stream of a POTW is adsorbed on the sludge or appears in the
sludge ac the hydroxide of the metal. Bench scale pilot studies have
shown that from about 25 percent to 75 percent of the copper passing
through the activated sludge process remains in solution in the final
effluent. Four-hour slug dosages of copper sulfate in concentrations
exceeding 50 mg/1 were reported u.o have severe effects on the removal
efficiency of an unacclimated systt-n, with the system returning to
normal in about 100 hours. Slug dosages of copper in the form of
copper cyanide were observed to have much more severe effects on the
activated sludge system, but the total system returned to normal in 24
hours.
In a recent study of 268 POTW, the median pass-through was over 80
percent for primary plants and 40 to 50 percent for trickling filter,
activated sludge, and biological treatment plants. POTW effluent
concentrations of copper ranged from 0.003 to 1.8 mg/1 (mean 0.126,
standard deviation 0."!42).
Copper which doe-5 not pass through the POTW will be retained in the
sludge where it wiil build up in concentration. The presence of
excessive levels of copper in sludge may limit its use on cropland.
Sewage sludge contains up to 16,000 mg/kg of copper, with 730 -ag/kg as
the mean value. These concentrations are significantly greater than
those normally found in soil, which usually range from 18 to 80 mg/kg.
Experimental data indicate that when dried sludge is spread over
tillable land, the copper tends to remain in place down to the depth
of tillage, except for copper which is taken up by plants grown in the
soil. Recent investigation has shown that the extractable copper
content of rludge-treated soil decreased with time, which suggests a
reversion of copper to less soluble forms was occurring.
Cyanidet121^. Cyanides are among the most toxic of pollutants
commonly observed in industrial wastewaters. Introduction of cyanide
into industrial processes is usually by dissolution of potassium
cyanide (KCN) or sodium cyanide »NaCN) in process waters. However,
hydrogen cyanide (HCN) formed when the above salts are dissolved in
water, is probably the most acutely lethal compound.
The relationship of pH to hydrogen cyanide formation is very
important. As pH is lowered to below 7, more than 99 percent of the
cyanide is present as HCN and less than 1 percent as cyanide ions.
Thus, at neutral pH, that of most living organisms, the mor» toxic
form of cyanide prevails.
Cyanide ions combine with numerous heavy .T.etal ior.s to form complexes.
The complexes are in equilibrium with HCN. Thus, the stability of the
metal-cyanide complex and the pH determine the concentration of HCN.
Stability of the metal-cyanide anion complexes is extremely variable.
Those forx.ed with zinc, copper, and cadmium are not stable - they
rapidly dissociate, with production of HCN, in near neutril or acid
waters. Some of the complexes are extremely stable. C^baltocyanide
is very resistant to acid distillation in the laboratory. Iron
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cyanide complexes are also stable, but undergo photodecomposition to
give HCN upon exposure to sunlight. Synergistic effects have been
demonstrated for the metal cyanide complexes making zinc, copper, and
cadmiun, cyanides more toxic than an equal concentration of sodium
cyanide.
The toxic mechanism of cyanide is essentially an inhibition of oxygen
metabolism, i.e., rendering the tissues incapable of exchanging
oxygen. The cyanogen compounds are true noncummulative protoplasmic
poisons. They arrest the activity of all forms of animal life.
Cyanide shows a very specific type of toxic action. It inhibits the
cytochrome oxidase system. This system is the one which facilitates
electron transfer from reduced metabolites to molecular oxygen. The
human body can convert cyanide to a nontoxic thiocyanate and elminiate
it. However, if the quantity of cyanide ingested is too great at one
time, the inhibition of oxygen utilization proves fatal before the
detoxifying reaction reduces the cyanide con- centration to a safe
level.
Cyanides are more toxic to fish than to lower forms of aquatic
organisms such as midge larvae, crustaceans, and mussels. Toxicity to
fish is a function of chemical torm and concentration, and is
influenced by the rate of metabolism (temperature), the level of
dissolved oxygen, and pH. In laboratory studies free cyanide
concentrations ranging from 0.05 to 0.15 mg/1 have been proven to be
fatal to sensitive fish species including trout, bluegill, and fathead
minnows. Levels above 0.2 mg/1 are rapidly fatal to most fish
species. Long term sublethal concentrations of cyanide as low as
0.01 mg/1 have been shown to affect the ability of fish to function
normally, e.g., reproduce, grow, and swim.
For the protection of human health from the toxic properties of
cyanide ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determined to be 0.200 mg/1.
Available data show taht adverse effects on aquatic life occur at
concentrations as low as 3.5 x 10~3 mg/1.
Persistance of cyanide in water is highly variable and depends upon
the chemical form of cyanide in the water, the concentration of
cyanide, and the nature of other constituents. Cyanide may be
destroyed by strong oxidizing agents such as permanganate and
chlorine. Chlorine is commonly used to oxidize strong cyanide
solutions. Carbon dioxide and nitrogen are the products of complete
oxidation. But if the reaction is not complete, the very toxic
compound, cyanogen chloride, may remain in the treatment system and
subsequently be released to the environment. Partial chlorination iray
occur as part of a POTW treatment, or during the disinfection
treatment of surface water for drinking water preparation.
Cyanides can interfere with treatment processes in POTW, or pass
through to ambient waters. At low concentrations and with acclimated
microflora, cyanide may be decomposed by microorganisms in anaerobic
and aerobic environments or waste treatment systems. However, data
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l!
indicate that much of the cyanide introduced passes through to the
POTW effluent. The mean pass-through of 14 biological plants was 71
percent. In a recent study of 41 POTW the effluent concentrations
ranged from 0.002 to 100 mg/1 (mean » 2.518, standard
deviation = 15.6). Cyanide also enhances the toxicity of metals
commonly found in POTW effluents, including the toxic pollutants
cadmium, zinc, and copper.
Data for Grand Rapids, Michigan, showed a significant decline in
cyanide concentrations downstream from the POTW after pretreat- ment
regulations were put in force. Concentrations fell from 0.66 mg/1
before, to 0.01 mg/1 after pretreatment was required.
Lead (122). Lead is a soft, malleable, ductible, blueish-gray,
metallic element, usually obtained from the mineral galena (lead
sulfide, PbS), anglesite (lead sulfate, PbS04), or cerussite (lead
carbonate, PbCO,). Because it is usually rissociated with minerals of
zinc, silver, copper, gold, cadmium, antimony, and arsenic, special
purification methods are frequently used before and after extraction
of the metal from the ore concentrate by smelting.
Lead is widely used for its corrosion resistance, sound and vibration
absorption, low melting point (solders), and relatively high
imperviousness to various forms of radiation. Small amounts of
copper, antimony and other metals can be alloyed with lead to achieve
greater hardness, stiffness, or corrosion resistance than is afforded
by the pure metal. Lead compounds are used in glazes and paints.
About one third of U.S. lead consumption goes into storage batteries.
About half of U.S. lead consumption is from secondary lead recovery.
U.S. consumption of lead is in the range of one million tons annually.
Lead ingested by humans produces a variety of toxic effects including
impaired reproductive ability, disturbances in blood chemistry,
neurological disorders, kidney damage, and adverse cardiovascular
effects. Exposure to lead in the diet results in permanent increase
in lead levels in the body. Most of the lead entering the body
eventually becomes localized in the bones where it accumulates. Lead
is a carcinogen or cocarcinogen in some species of experimental
animals. Lead is terratogenic in experimental animals. Mutangenicity
data are not available for lead.
For the protection of human health from the toxic properties of lead
ingested through water and through contaminated aquatic organisms, the
ambient water criterion is 0.050 mg/1. Available data show that
adverse effects on aquatic life occur at concentrations as low as 7.5
x 10-* mg/1.
Lead is not destroyed in POTW, but is passed through to the effluent
or retained in the POTW sludge; it can interfere with POTW treatment
processes and can limit the usefulness of POTW sludge for application
to agricultural croplands. Threshold concentration for inhibition of
the activated sludge process is 0.1 mg/1, and for the nitrification
process is 0.5 mg/1. In a study of 214 POTW, median pass through
336
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values were over 80 percent for primary plants and over 60 percent for
trickling filter, activated sludge, and biological process plants.
Lead concentration in POTW effluents ranged from 0.003 to 1.8 mg/1
(means - 0.106 mg/1, standard deviation = 0.222).
Application of lead-containing sludge to cropland should not affect
the uptake by crops under most conditions because normally lead is
strongly bound by soil. However, under the unusual conditions of low
pH (less than 5.5) and low concentrations of labile phosphorus, lead
solubility is increased and plants can accumulate lead.
Nickel(124). Nickel is seldom found in nature as the pure elemental
metal. It is a reltively plentiful element and is widely distributed
throughout the earth's crust. It occurs in marine organisms and is
found in the oceans. The chief commercial ores for nickel are
pentlandite [(Fe,Ni)9SB], and a lateritic ore consisting of hydrated
nickel-iron-magnesium silicate.
Nickel has many and varied uses. It is used in alloys and as the pure
metal. Nickel salts are used for electroplating baths.
The toxicity cf nickel to man is thought to be very low, and systemic
poisoning of human beings by nickel or nickel salts is almost unknown.
In nonhuman mammals nickel acts to inhibit insulin release, depress
growth, and reduce cholesterol. A high incidence of cancer of the
lung and nose has been reported in humans engaged in the refining of
nickel.
Nickel salts can kill fish at very low concentrations. However,
nickel has been found to be less toxic to some fish than copper, zinc,
and iron. Nickel :.s present in coastal and open ocean water at con-
centrations in the range of 0.0001 to 0.006 mg/1 although the most
common values are 0.002 - 0.003 mg/1. Marine animals contain up to
0.4 mg/1 and marine plants contain up to 3 mg/1. Higher nickel
concentrations have been reported to cause reduction in photosynthetic
activity of the giant kelp. A low concentration was found to kill
oyster eggs.
For the protection of human health based on the toxic properties of
nickel ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determined to be 0.134 mg/1.
If contaminated aquatic organisms are consumed, excluding consumption
of water, the ambient water criterion is determined to be 1.01 mg/1.
Available data show that adverse effects on aquatic life occur for
total recoverable nickel concentrations as low as 0.032 mg/1.
Nickel is not destroyed when treated in a POTW, but will either pass
through to the POTW effluent or be retained in the POTW sludge. It
can interfere with POTW treatment processes and can also limit the
usefulness of municipal sludge.
Nickel salts have caused inhibition of the biochemical oxidation of
sewage in a POTW. In a pilot plant, slug doses of nickel
587
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significantly reduced normal treatment efficiencies for a few hours,
but the plant acclimated itself somewhat to the slug dosage and
appeared to achieve normal treatment efficiencies within 40 hours. It
has been reported that the anaerobic digestion process is inhibited
only by high concentrations of nickel, while a low concentration of
nickel inhibits the nitrification process.
The influent concentration of nickel to POTW facilities has been
observed by the EPA to range from 0.01 to 3.19 mg/1, with a median of
0.33 mg/1. In a study of 190 POTW, nickel pass-through was greater
than 90 percent for 82 percent of the primary plants. Median
pass-through for trickling filter, activated sludge, and biological
process plants was greater than 80 percent. POTW effuent
concentrations ranged from 0.002 to 40 mg/1 (mean = 0.410, standard
deviation = 3.279).
Nickel not passed through the POTW will be incorporated into the
sludge. In a recent two-year study of eight cities, four of the
cities had median nickel concentrations of over 350 mg/kg, and two
were over 1,000 mg/kg. The maximum nickel concentration observed was
4,010 mg/kg.
Nickel is found in nearly all soils, plants, and waters. Nickel has
no known essential function in plants. In soils, nickel typically is
found in the range from 10 to 100 mg/kg. Various environmental
exposures to -lickel appear to correlate with increased incidence of
tumors in man. For example, cancer in the maxillary antrum of snuff
users may result from using plant material grown on soil high in
nickel.
Nickel toxicity may develop in plants from application of sewage
sludge on acid soils. Nickel has caused reduction of yields for a
variety of crops including oats, mustard, turnips, and cabbage. In
one study nickel decreased the yields of oats significantly at 100
mg/kg.
Whether nickel exerts a toxic effect on plants depends on several soil
factors, the amount of nickel applied, and the contents of other
metals in the sludge. Unlike copper and zinc, which are more
available from inorganic sources than from sludge, nickel uptake by
plants seems to be promoted by the presence of the organic matter in
sludge. Soil treatments, such as liming reduce the solubility of
nickel. Toxicity of nickel to plants is enhanced in acidic soils.
Selenium^125). Selenium (chemical symbol Se) is a nonmetallic element
existing in several allotropic forms. Gray selenium, which has a
metallic appearance, is the stable form at ordinary temperatures and
melts at 220°C. Selenium is a major component of 38 minerals and a
minor component of 37 others found in various parts of the world.
Most selenium is obtained as a by-product of precious metals recovery
from electrolytic copper refinery slimes. U.S. annual production at
one time reached one million pounds.
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Principal uses of selenium are in semi-conductors, pigments,
decoloring of glass, zerography, and metallurgy. It also is used to
produce ruby glass used in signal lights. Several selenium compounds
are important oxidizing agents in the synthesis of organic chemicals
and drug products.
While results of some studies suggest that selenium may be an
essential element in human nutrition, the toxic effects of selenium in
humans are well established. Lassitude, loss of, hair, discoloration
and loss of fingernails are symptoms of selenium poisoning. In a
fatal case of ingestion of a larger dose of selenium acid, peripheral
vascular collapse, pulumonary edema, and coma occurred. Selenium
produces mutagenic and teratogenic effects, but it has not been
established as exhibiting carcinogenic activity.
For the protection of human health from the toxic properties of
selenium ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determind to be 0.010 mg/1.
Available data show that adverse effects on aquatic life occur at
concentrations higher than that cited for human toxicity.
Very few data are available regarding the behavior of selenium in
POTW. One EPA survey of 103 POTW revealed one "POTW using biological
treatment and having selenium in the influent. Influent concentration
was 0.0025 mg/1, effluent concentration was 0.0016 mg/1 giving a
removal of 37 percent. It is not known to be inhibitory to POTW
processes. In another study, sludge from POTW in 16 cities was found
to contain from 1.8 to 8.7 mg/kg selenium, compared to 0.01 to 2 mg/kg
in untreated soil. These concentrations of selenium in sludge present
a potential hazard for humans or other mammuals eating crops grown on
soil treated with selenium containing sludge.
Silver(126). Silver is a soft, lustrous, white metal that is
insoluble in water and alkali. In nature, silver is found in the
elemental state (native silver) and combined in ores such as argentite
(AgzS), horn silver (AgCl), proustite (Ag3AsS3), and pyrargyrite
(Ag3SbS3). Silver is used extensively in several industries, among
them electroplating.
Metallic silver is not considered to be toxic, but most of its salts
are toxic to a large number of organisms. Upon ingestion by humans,
many silver salts are absorbed in the circulatory system and deposited
in various body tissues, resulting in generalized or sometimes
localized gray pigmentation of the skin and mucous membranes know as
argyria. There is no known method for removing silver from the
tissues once it is deposited, and the effect is cumulative.
Silver is recognized as a bactericide and doses from 1 x 10~* to 5 x
10~4 mg/1 have been reported as sufficient to sterilize water. The
ambient water criterion to protect human health from the toxic
properties of silver ingested through water and through contaminated
aquatic organisms is 0.05 mg/1. Available data show that adverse
58-J
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effects on aquatic life occur at total recoverable silver
concentrations as low as 1.2 x 10~3 mg/1.
The chronic toxic effects of silver on the aquatic environment have
not been given as much attention as many other heavy metals. Data
from existing literature support the fact that silver is very toxic to
aquatic organisms. Despite the fact that silver is nearly the most
toxic of the heavy metals, there are insufficient data to adequately
evaluate even the effects of hardness on silver toxicity. There are
no data available on the toxicity of different forms of silver.
There is no available literature on the incidental removal of silver
by POTW. An incidental removal of about 50 percent is assumed as
being representative. This is the highest average incidental removal
of any metal for which data are available. (Copper has been indicated
to have a median incidental removal rate of 49 percent).
Bioaccumulation and concentration of silver from sewage sludge has not
been studied to any great degree. There is some indication that
silver could be bioaccumulated in mushrooms to the extent that there
could be adverse physiological effects on humans if they consumed
large quantites of mushrooms grown in silver enriched soil. The
effect, however, would tend to be unpleasnat rather than fatal.
There is little summary data available on the quantity of silver
discharged to POTW. Presumably there would be a tendency to limit its
discharge from a manufacturing facility because of its high intrinsic
value.
Thallium (127). Thallium (Tl) is a soft, silver-white, dense,
malleable metal. Five major minerals contain 15 to 85 percent
thallium, but they are not of commerical importance because the metal
is produced in sufficient quantity as a by-product of lead-zinc
smelting of sulfide ores. Thallium melts at 304°C. U.S. annual
production of thallium and its compounds is estimated to be 1500 Ib.
Industrial uses of thallium include the manufacture of alloys,
electronic devices and special glass. Thallium catalysts are used for
industrial organic syntheses.
Acute thallium poisoning in humans has been widely described.
Gastrointestinal pains and diarrhea are followed by abnormal sensation
in the legs and arms, dizziness, and, later, loss of hair. The
central nervous system is also affected. Somnolence, delerium or coma
may occur. Studies on the teratogenicity of thallium appear
inconclusive; no studies on mutagenicity were found; and no published
reports on carcinogenicity of thallium were found.
For the protection of human health from the toxic properties of
thallium ingested through water and contaminated aquatic organisms,
the ambient water criterion is 1.34 x 1 0~2 mg/1. If contaminated
aquatic organisms alone are consumed, excluding consumption of water,
the ambient water criterion is determined to be 48 mg/1. Available
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data show that adverse effects on aquatic life occur at concentrations
higher than those cited for human health risks.
No reports were found regarding the behavior of thallium in POTW. It
will not be degraded, therefore it must pass through to the effluent
or be removed with the sludge. However since the sulfide (T1S) is
very insoluble, if appreciable sulfide is present dissolved thallium
in the influent to POTW may be precipitated into the sludge.
Subsequent use of sludge bearing thallium compounds as a soil
amendment to crop bearing soils may result in uptake of this element
by food plants. Several leafy garden crops (cabbage, lettuce, leek,
and endive) exhibit relatively higher concentrations of thallium than
other foods such as meat.
Zinc(128). Zinc occurs abundantly in the earth's crust, concentrated
in ores. It is readily refined into the pure, stable, silvery-white
metal. In addition to its use in alloys, zinc is used as a protective
coating on steel. It is applied by hot dipping (i.e. dipping the
steel in molten zinc) or by electroplating.
Zinc can have an adverse effect on man and animals at high con-
centrations. Zinc at concentrations in excess of 5 mg/1 causes an
undesirable taste and odor which persists through conventional
treatment. For the prevention of adverse effects due to these
organoleptic properties of zinc, concentrations in ambient water
should not exceed 5 mg/1. Available data show that adverse effects on
aquatic life occur at concentrations as low as 0.047 mg/1.
Toxic concentrations of zinc compounds cause adverse changes in the
morphology and physiology of fish. Lethal concentrations in the range
of 0.1 mg/1 have been reported. Acutely toxic concentrations induce
cellular breakdown of the gills, and possibly the clogging of the
gills with mucous. Chronically toxic concentrations of zinc compounds
cause general enfeeblement and widespread histological changes to many
organs, but not to gills. Abnormal swimming behavior has been
reported at 0.04 mg/1. Growth and maturation are retarded by zinc.
It has been observed that the effects of zinc poisoning may not become
apparent immediately, so that fish removed from zinc-contaminated
water may die as long as 48 hours after removal.
In general, salmonoids are most sensitive to elemental zinc in soft
water; the rainbow trout is the most sensitive in hard waters. A
complex relationship exists between zrnc concentration*, dissolved zinc
concentration, ^.oH, temperature, and calcium and magnesium
concentration. Prediction of harmful effects has been less than
reliable and controlled studies have not been extensively documented.
The major concern with zinc Compounds in marine waters is not with
acute lethal effects, but rather with the long-term sublethal effects
of the metallic compounds and complexes. Zinc accumulates in some
marine species, and marine animals contain zinc in the range of 6 to
1500 mg/kg. From the point of view of acute lethal effects,
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invertebrate marine animals seem to be the most sensitive organism
tested.
agricultural uses of the water.
can interfere with treatment processes in the POTW and can also li
the usefuleness of municipal sludge.
in slug doses, and particularly in the presence of copper
ss
readily adsorbs zinc.
Tn a ^tudv of 258 POTW, the median pass-through values were 70 to 88
3.6 mg/1 (mean = 0.330, standard deviation = 0.464).
. c.
of Sewaq4 Sludge to soil will generally increase tne concentration of
° nc fn the ^oil. Zinc can be toxic to plants, pending upon soil
PH. Lettuce, tomatoes, turnips, mustard, kale, and beets are
especially sensitive to zinc contamination.
sis:e
SanuZactured from pseudocumene, or by catalytic isomer ization
hydrocarbon fraction.
V>2
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Xylene is predominately used as a solvent, for the manufacture of dyes
and other organics, and as a raw material for production of benzoic
acid, phthalic anhydride and other acids and esters used in the
manufacture of polyester fibers.
Xylene has been shown to have a narcotic effect on humans exposed to
high concentrations. The chronic toxicity of xylene has not been
defined, however, it is less toxic than benzene.
Data on the behavior of xylene in POTW are not available. However,
the methyl groups in xylene tend to transfer electrons to the benzene
ring and make it more susceptible to biochemical oxidation. This
observation in addition to the low water solubility of xylene, leads
to the expectation that aeration processes will remove some xylene
from the POTW.
Aluminum. Aluminum is a nonconventional pollutant. It is a silvery
white metal, very abundant in the earths crust (8.1%), but never found
free in nature. Its principal ore is bauxite. Alumina (A1203) is
extracted from the bauxite and dissolved in molten cryolite. Aluminum
is produced by electrolysis of this melt.
Aluminum is light, malleable, ductile, possesses high thermal and
electrical conductivity, and is non-magnetic. It can be formed,
machined or cast. Although aluminum is very reactive, it forms a
protective oxide film on the surface which prevents corrosion under
many conditions. In contact with other metals in presence of moisture
the protective film is destroyed and voluminous white corrosion
products form. Strong acids and strong alkali also break down the
protective film. Aluminum is one of the principal basis metals used
in the coil coating industry.
Aluminum is nontoxic and its salts are used as coagulants in water
treatment. Although some aluminum salts are soluble, alkaline
conditions cause precipitation of the aluminum as a hydroxide.
Aluminum is commonly used in cooking utensils. There are no reported
adverse physiological effects on man from low concentrations of
aluminum in drinking water.
Aluminum does not have any adverse effects on POTW operation at any
concentrations normally encountered.
Ammonia. Ammonia (chemical formula NH3) is a non-conventional
pollutant. It is a colorless gas with a very pungent odor, detectable
at concentrations of 20 ppm in air by the nose, and is very soluble in
water (570 gm/1 at 25°C). Ammonia is produced industrially in very
large quantities (nearly 20 millions tons annually in the U.S.). It
is converted to ammonium compounds or shipped in the liquid form (it
liquifies at -33°C). Ammonia also results from natural processes.
Bacterial action on nitrates or nitrites, as well as dead plant and
animal tissue and animal wastes produces ammonia. Typical domestic
wastewaters contain 12 to 50 mg/1 ammonia.
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The principal use of ammonia and its compounds is as fertilizer. High
amounts are introduced into soils and the water runoff from
agricultural land by this use. Smaller quantities of ammonia are used
as a refrigerant. Aqueous ammonia {2 to 5 percent solution) is widely
used as a household cleaner. Ammonium compounds find a variety of
uses in various industries.
Ammonia is toxic to humans by inhalation of the gas or ingestion of
aqueous solutions. The ionized form (NH4+) is less toxic than the
un-ionized form. Ingestion of as little as one ounce of household
ammonia has been reported as a fatal dose. Whether inhaled or
ingested, ammonia acts distructively on mucous membrane with resulting
loss of function. Aside from breaks in liquid ammonia refrigeration
equipment, industrial hazard from ammonia exists where solutions of
ammonium compounds may be accidently treated with a strong alkali,
releasing ammonia gas. As little as 150 ppm ammonia in air is
reported to cause laryngeal spasm, and inhalation of 5000 ppm in air
is considered sufficient to result in death.
Freshwater ambient water criteria for total ammonia are pH and
temperature dependent; un-ionized ammonia criteria is 0.02 mg/1. The
reported odor threshold for ammonia in water is 0.037 mg/1.
Un-ionized ammonia is acutely or chronically toxic to many important
freshwater and marine aquatic organisms at ambient water
concentrations below 4.2 mg/1. Salmonoid fishes are especially
sensitive to the toxic effects of un-ionized ammonia at concentrations
as low as 0.025 mg/1 during prolonged exposure. Because the
proportion of un-ionized ammonia varies with environmental conditions
and cannot be d.rectly controlled in the ambient water, total ammonia
is the pollutant which must be controlled.
The behavior of ammonia in POTW is well documented because it is a
natural component of domestic wastewaters. Only very high
concentrations of ammonia compounds could overload POTWs. One study
has shown that concentrations of un-ionized ammonia greater than
90 mg/1 reduce gasification in anaerobic digesters and concentrations
of 140 mg/1 stop digestion competely. Corrosion of copper piping and
excessive consumption of chlorine also result from high ammonia
concentrations. Interference with aerobic nitrification processes can
occur when large concentrations of ammonia suppress dissolved oxygen.
Nitrites are then produced instead of nitrates. Elevated nitrite
concentrations in drinking water are known to cause infant
methemoglobinerr.ia.
Fluoride. Fluoride ion (F~) is a nonconventional pollutant. Fluorine
is an extremely reactive, pale yellow, gas which is never found free
in nature. Compounds of fluorine - fluorides - are found widely
distributed in nature. The principal minerals containing fluorine are
fluorspar (CaF?) and cryolite (Na.,AlFe). Although fluorine is
produced commercially in small quantities by electrolysis of potassium
bifluoride in anhydrous hydrogen fluoride, the elemental form bears
little relation to the combined ion. Total production of fluoride
chemicals in the U.S. is difficult to estimate because of the varied
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uses. Large volume usage compounds are: Calcium fluoride (est.
1,500,000 tons in U.S.) and sodium fluoroaluminate (est. 100,000 tons
in U.S.). Some fluoride compounds and their uses are: sodium
fluoroaiuminate - aluminum production; calcium fluoride - steelir.aking,
hydrofluoric acid production, enamel, iron foundry; boron trifluoride
- organic synthesis; antimony pentafluoride - fluorocarbon production;
fluoboric acid and fluobcrates - electroplating; perchloryl fluoride
(ClOjF) - rocket fuel oxidizer; hydrogen fluoride - organic fluoride
manufacture, pickling acid in stainless steelmaking, manufacture of
alumium fluoride; sulfur hexafluoride - insulator in high voltage
transformers; polytetrafluoroethylene - inert plastic. Sodium
fluoride is used at a concentration of about 1 ppm in many public
drinking water supplies to prevent tooth decay in children.
The toxic effects of fluoride on humans include severe
gastroenteritis, vomiting diarrhea, spasms, weakness, thirst, failing
pulse and delayed blood coagulation. Most observations of toxic
effects are made on individuals who intentionally or accidentally
ingest sodium fluoride intended for use as rat poison or insecticide.
Lethal doses for adults are estimated to be as low as 2.5 g. At 1.5
ppm in drinking water, mottling of tooth enamel is reported, and 14
ppm, consumed over a period of years, may lead to deposition of
calcium fluoride in bone and tendons.
Very few data are available on the behavior of fluoride in POTW.
Under usual operating conditions in POTW, fluorides pass through into
the effluent. Very little of the fluoride entering conventional
primary and secondary treatment processes is removed. In one study of
POTW influents conducted by the U.S. EPA, nine POTW reported
concentrations of fluoride ranging from 0.7 mg/1 to 1.2 mg/1, which is
the range of concentrations used for fluoridated drinking water.
Iron. Iron is a nonconventional polluant. It is an abundant metal
found at many places in the earth's crust. The most common iron ore
is hematite (Fez03) from which iron is obtained by reduction with
carbon. Other forms of commercial ores are magnetite (Fe304) and
taconite (FeSiO). Pure iron is not often found in commercial use, but
it is usually alloyed with other metals and minerals. The most common
of these is caroon.
Iron is the basic element in the production of steel. Iron with
carbon is used for casting of major parts of machines and it can be
machined, cast, formed, and welded. Ferrous iron is used in paints,
while powdered iron can be sintered and used in powder metallurgy.
Iron compounds are also used to precipitate other metals and
undesirable minerals from industrial wastewater streams.
Corrosion products of iron in water cause staining of porcelain
fixtures, and ferric iron combines with tannin to produce a dark
violet color. The presence of excessive iron in water discourages
cows from drinking and thus reduces milk production. High
concentrations of ferric and ferrous ions in water kill most fish
introduced to the solution within a few hours. The killing action is
-*"Jj-j-
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attributed to coatings of iron hydroxide precipitates on the gills.
Iron oxidizing bacteria are dependent on iron in water for growth.
These bacteria form slimes that can affect the aesthetic values of
bodies of water and cause stoppage of flows in pipes.
Iron is an essential nutrient and micro-nutrient for all forms of
growth. Drinking water standards in the U.S. set a limit of 0.3 mg/1
of iron in domestic water supplies based on aesthetic and organoleptic
properties of iron in water.
High concentrations of iron do not pass through a POTW into the
effluent. In some POTW iron salts are added to coagulate precipitates
and suspended sediments into a sludge. In an EPA study of POTW the
concentration of iron in the effluent of 22 biological POTW meeting
secondary treatment performance levels ranged from 0.048 to 0.5C9 mg/1
with a median value of 0.25 mg/1. This represented removals of 76 to
97 percent with a median of 87 percent removal.
Iron in sewage sludge spread on land used for agricultural purposes is
not expected to have a detrimental effect on crops grown on the land.
Phenols(Total). "Total Phenols" is a nonconventional pollutant
pa'rameter. Total phenols is the result of analysis using the 4-AAP >ijj
(4-aminoantipyrene) method. This analytical procedure measures the '
color development of reaction products between 4-AAP and some phenols.
The results are reported as phenol. Thus "total phenol" is not total
phenols because many phenols (notably nitrophenols) do not react.
Also, since each reacting phenol contributes to the color development
to a different degree, and each phenol has a molecular weight
different from others and from phenol itself, analyses of several
mixtures containing the same total concentration in mg/1 of several
phenols will give different numbers depending on the proportions in
the particular mixture.
Despite these limitations of the analytical method, total phenols is a
useful analysis when the mix of phenols is relatively constant and an
inexpensive monitoring method is desired. In any given plant or even
in an industry subcategory, monitoring of "total phenols" provides an
indication of the concentration of this group of toxic pollutants as
well as those phenols not selected as toxic pollutants. A further
advantage is that the method is widely used in water quality
determinations.
In an EFA survey of 103 POTW the concentration of "total phenols"
ranged grom 0.0001 mg/1 to 0.176 mg/1 in the influent, with a median
concentration of 0.016 mg/1. Analysis of effluents from 22 of these
same POTW which had biological treatment meeting secondary .treatment
performance levels showed "total phenols" concentrations ranging from
0 mg/1 to 0.203 mg/1 with a median of 0.007. Removals were 64 to 100
percent with a median of 78 percent.
It must be recognized, however, that six of the eleven toxic pollutant
phenols could be present in high concentrations and not be detected.
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Conversely, it is possible, but not probable, to have a high "total
phenol" concentration without any phenol itself or any of the ten
other toxic pollutant phenols present. A characterization of the
phenol mixture to be monitored to establish constancy of composition
will allow "total phenols" to be used with confidence.
Oil and Grease. Oil and grease are taken together as one pollutant
parameter. This is a conventional polluant and some of its components
are:
1. Light Hydrocarbons - These include light fuels such as gasoline,
kerosene, and jet fuel, and miscellaneous sol- vents used for
industrial processing, degreasing, or cleaning purposes. The I
presence of these light hydro- carbons may make the removal of
other heavier oil wastes more difficult.
2. Heavy Hydrocarbons, Fuels, and Tars - These include the crude
oils, diesel oils, #6 fuel oil, residual oils, slop oils, and in
some cases, asphalt and road tar.
3. Lubricants and Cutting Fluids - These generally fall in- to two
classes: nonemulsifiable oils such as lubrica- ting oils and
greases and emulsifiable oils such as water soluble oils, rolling
oils, cutting oils, and draw- ing compounds. Emulsifiable oils
may contain fat soap or various other additives.
4. Vegetable and Animal Fats and Oils - These originate primarily
from processing of foods and natural products.
These compounds can settle or float and may exist as solids or liquids
depending upon factors such as method of use, production process, and {
temperature of wastewater. jj
'< l
Oil and grease even in small quantities cause troublesome taste and
odor problems. Scum lines from these agents are produced on water
treatment basin walls and other containers. Fish and water fowl are
adversely affected by oils in their habitat. Oil emulsions may adhere
to the gills of fish causing suffocation, and the flesh of fish is
tainted when microorganisms that were exposed to waste oil are eaten.
Deposition of oil in the bottom sediments of water can serve to
inhibit normal benthic growth. Oil and grease exhibit an oxygen
demand.
Many of the organic priority pollutants will be found distributed
between the oily phase and the aqueous phase in industrial
wastewaters. The presence of phenols, PC3s, PAHs, and almost any
other organic pollutant in the oil and grease make characterization of
this parameter almost impossible. However, all of these other
organics add to the objectionable nature of the oil and grease.
Levels of oil and grease which are toxic to aquatic organisms vary
greatly, depending on the type and the species susceptibility.
However, it has been reported that crude oil in concentrations as low
5'-) 7
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as 0.3 mg/1 is extremely toxic to fresh-water fish. It has been
recommended that public water supply sources be essentially free from
oil and grease.
Oil and grease in quantities of 100 1/sq km show up as a sheen on the
surface of a body of water. The presence of oil slicks decreases the
aesthetic value of a waterway.
Oil and grease is compatible with a POTW activated sludge process in
limited quantity. However, slug loadings or high concentrations of
oil and grease interfere with biological treatment processes. The
oils coat surfaces and solid particles, preventing access of oxygen,
and sealing in some microorganisms. Land spreading of POTW sludge
containing oil and grease uncontaminated by toxic pollutants is not
expected to affect crops grown on the treated land, or animals eating
those crops.
pH. Although not a specific pollutant, pH is related to the acidity
or alkalinity of a wastewater stream. It Ls not, however, a measure
of either. The term pH is used to describe the hydrogen ion
concentration (or activity) present in a given solution. Values for
pH range from 0 to 14, and these numbers are the negative logarithms
of the hydrogen ion concentrations. A pH of 7 indicates neutrality.
Solutions with a pH above 7 are alkaline, while those solutions with a
pH below 7 are acidic. The relationship of pH and acidity and
alkalinity is not necessarily linear or direct. Knowledge of the
water pH is useful in determining necessary treasures for corroison
control, sanitation, and disinfection. Its value is also necessary in
the treatment of industrial wastewaters to determine amounts of
chemcials rec/iired to remove pollutants and to measure their
effectiveness. Removal of pollutants, especially dissolved solids is
affected by the pH of the wastewater.
Waters with a pH below 6.0 are corrosive to water works structures,
distribution lines, and household plumbing fixtures and can thus add
constituents to drinking water such as iron, copper, zinc, cadmiurr,,
and lead. The hydrogen ion concentration can affect the taste of the
water and at a low pH, water tastes sour. The bactericidal effect of
chlorine is weakened as the pH increases, and it is advantageous to
keep the pH close to 7.0. This is significant for providng safe
drinking water.
Extremes of pH or rapid pH changes can exert stress conditions or kill
aquatic life outright. Even moderate changes from acceptable criteria
limits of ptt are deleterious to some species. The relative toxicity
to aquatic life of many materials is increased by changes in the water
pH. For example, metallocyanide complexes can increase a
thousand-fold in toxicity with a drop of 1.5 pH units.
Because of the universal nature of pH and its effect on water quality
and treatment, it is selected as a pollutant parameter for many
industry categories. A neutral pH range (approximately 6-9) is
generally desired because either extreme beyond this range has a
v>s
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deleterious effect on receiving waters or the pollutant nature of
other wastewater constituents.
Pretreatment for regulation of pH is covered by the "General
Pretreatment Regulations for Exisiting and New Sources of Pollution,"
40 CFR 403.5. This section prohibits the discharge to a POTW of
"pollutants which will cause corrosive structural damage to the POTW
but in no case discharges with pH lower than 5.0 unless the works is
specially designed to accommodate such discharges."
Sulfides. Sulfides are constituents of many industrial wastes such" as
those from tanners, paper mills, chemical plants, and gas works; but
they are also generated in sewage and some natural waters by the
anerobic decomposition of organic matter. When added to water,
soluble sulfide salts such as Na2S dissociate into sulfide ions which
in turn react with the hydrogen ions in the water to form HS- or H,S,
the proportion of each depending upon the resulting pH value.
Due to che unpleasant taste and odor which exist when sulfides are
present in water, it is unlikely that any person or animal would
consume a harmful dose. The threshold level of taste and smell are
reported to be 0.2 mg/1 of sulfides in pump-mill wastes. For
industrial uses, however, even small traces of sulfides are often
detrimental.
The toxicity of sulfide solutions toward fish increases as the pH
value is lowered, i.e., the H?S or HS- appears to be the principle
toxic agent. Experiments with trout substantiate this statement.
However, inorganic sulfides have also proved fatal to trout at
concentrations between 0.5 and 1.0 mg/1 as sulfide, even in neutral
and somewhat alkaline solutions.
Tin. Tin is a silver-white, lustrous and malleable ?etal with a
density of 7.31 g/ml. The melting point of tin is 231.9°C while the
boiling point is 2507°c.
Tin is used chiefly for tin-plating, soldering alloys and babbitt type
metals.
Tin is not present in natural waters but it may occur in industrial
wastes. Tin salts therefore, may reach surface waters or groundwater;
but because many of the salts are insoluble in water, it is unlikely
that much of the tin will remain in solution or suspension. No
reports have been uncovered to indicate that tin can be detrimental in
domestic water supplies.
Rats have tolerated 25 mg or more of sodium stannuous tartrate in the
diet over a period of 4-12 months without ill effects. Similar tests
with other animals had similar results - no ill effects. On the basis
of these feeding experiments, it is unlikely that any concentration of
tin that could occur in water would be detrimental to livestock.
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It is apparent that trace concentrations of tin are beneficial to
fish. However, higher levels have proved fatal to eels which were
tested.
Total Suspended Solids(TSS). Suspended solids include both organic
and inorganic materials. The inorganic compounds include sand, silt,
and clay. The organic fraction includes such materials as grease,
oil, tar, and animal and vegetable waste products. These solids may
settle out rapidly, and bottom deposits are often a mixture of both
organic and inorganic solids. Solids may be suspended in water for a
time and then settle to the bed of the stream or lake. These solids
discharged with man's wastes may be inert, slowly biodegradable
materials, or rapidly decomposable substances. While in suspension,
suspended solids increase the turbidity of the water, reduce light
penetration, and impair the photosynthetic activity of aquatic plants.
Supended solids in water interfere with many industrial processes and
cause foaming in boilers and incrustastions on equipment exposed to
such water, especially as the temperature rises. They are .undesirable
in process water used in the manufacture of steel, in the textile
industry, in laundries, in dyeing, and in cooling systems.
Solids in suspension are aesthetically displeasing. When they settle
to form sludge deposits on the stream or lake bed, they are often
damaging to the life in the water. Solids, when transformed to sludge
deposit, may do a variety of damaging things, including blanketing the
stream or lake bed and thereby destroying the living spaces for those
benthic organisms that would otherwise occupy the habitat. When of an
organic nature, solids use a portion or all of the dissolved oxygen
available in the area. Organic materials also serve as a food source
for sludgeworms and associated organisms.
Disregarding any toxic effect attributable to substances leached out
by water, suspended solids may kill fish and shellfish by causing
abrasive injuries and by clogging the gills and respiratory passages
of various aquatic fauna. Indirectly, suspended solids are inimical
to aquatic life because they screen out light, and they promote and
maintain the development of noxious conditions through oxygen
depletion. This results in the killing of fish and fish food
organisms. Suspended solids also reduce the recreational value of the
water.
Total suspended solids is a traditional pollutant which is compatible
with a well-run POTW. This pollutant with the exception of those
components which are described elsewhere in this section, e.g., heavy
metal components, does not interfere with the operation of a POTW.
However, since a considerable portion of the innocuous TSS may be
inseparably bound to the constituents which do interfere with POTW
operation, or produce unusable sludge, or subsequently dissolve to
produce unacceptable POTW effluent, TSS may be considered a toxic
waste hazard.
•U.S. noVLIU>MKST P1IINT1NG (HFlCt: 19H2-O-361-085/4451
600
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