-------
high sensitivity to strong and weak carcinogens produced results
which were marginally significant. Thus potential carcinogenic
effects of methylene chloride are not confirmed or denied, but
are under continuous study. These studies are difficult to
conduct for two reasons. First, the low boiling point (40° C) of
methylene chloride makes it difficult to maintain the compound at
370 c during incubation. Secondly, all impurities must be
removed because the impurities themselves may be carcinogenic.
These complications also make the test results difficult to
interpret.
For the protection of human health from the potential
carcinogenic effects due to exposure to methylene chloride
through ingestion of contaminated water and contaiminated aquatic
organisms, the ambient water concentration should be zero based
on the non-threshold assumption for this chemical. However, zero
level may not be attainable at the present time. Thefefore, the
levels which may result in incrmental increase of cancer risk
over the lifetime are estimated at 10-*, 10-* and 10~7. The
corresponding recommended criteria are 0.0019 mg/1, 0.00019 mg/1,
and 0.000019 mg/1.
The behavior of methylene chloride in POTW has not been studied
in any detail. However, the biochemical oxidation of this
compound was studied in one laboratory scale at concentrations
higher than those expected to be contained by most municipal
wastewaters. After five days no degradation of methylene
chloride was observed. The conclusion reached is that biological
treatment produces little or no removal by degradation of
methylene chloride in POTW.
The high vapor pressure of methylene chloride is expected to
result in volatilization of the compound from aerobic treatment
steps in a POTW. It has been reported that methylene chloride
inhibits anerobic processes in a POTW. Methylene chloride that
is not volatilized in the POTW is expected to pass through into
the effluent.
The most recent EPA study of POTW removal of toxic organics
indicates that methylene chloride is approximately 56 percent
removed.
Naphthalene (55). Naphthalene is an aromatic hydrocarbon with
two orthocondensed benzene rings and a molecular formula of
C10H8. 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 at 20<> C). Napthalene is the most abundant single component
of coal tar. Production is more than a third of a million tons
192
-------
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
2£?<«ii u P^ents, and Pharmaceuticals. Chlorinated and
Eavfnaiiy X K?!nated naPhthalenes are used in some solvent
mixtures. Naphthalene is also used as a moth repellent.
f16' 4.l?9e?ted, by humans, has reportedly caused vision
(cataracts), hemolytic anemia, and occasionally, renal dis-
«e ™?€K ef£ects ?f naphthalene ingestion are confirmed by
™*Hif ^oratory animals. No carcinogenicity studies are
available which can be used to demonstrate carcinogenic activity
for naphthalene. Naphthalene does bioconcentrati in aqiatic
inSUff ici*nt data - -"«<* to bJ. any
thi^fii?^ nUm^ ?f studies nave been conducted to determine
tne effects of naphthalene on aquatic organisms. The data from
those studies show only moderate toxicity.
°f ""* of the toxi' organic pollutants has
in laboratory scale studies at concentrations
normally be expected in municipal wastewaters.
n-0nS ,relating ^lecular structure to ease of
degradation have been developed for all of these pollutants. The
conclusion reached by study of the limited data is that biologi-
cal treatment produces a high removal by degradation of naphthal-
rec.e*t study has shown that microorganisms can degrade
waVe?. ^^ C°mP°Und' ™* --"i-f 1? to
Naphthalene has been detected in sewage plant effluents at con-
centrations up to 0.022 mg/1 in studies carried out by the U.S.
f ? i Jn£iiLe,nt levels were not reported. The most recent EPA
study of POTO removal of toxic organics indicates that naphthal-
ene is approximately 85 percent removed.
^ i, - ^^' N-nitrosodiphenylamine
cal1 nitrous diphenylamide is a yellow
i r manufa?turfduby nitrosation of diphenylamine.
It melts at 66<>o c and 1S insoluble in water, but soluble in
f fl nac °rganic solvents other than hydrocarbons. Production in
used f; hf aPProache? ^ 5°2 tone per year. The compound is
used as a retarder for rubber vulcanization and as a pesticide
for control of scorch (a fungus disease of plants). Pesi;iciae
?I^°S° SomP°un?s are acutely toxic to every animal species
tested and are also poisonous to humans. N-nitrosodiphenylamine
toxicity in adult rats lies in the mid range of the values for
60
193
-------
N-nitroso compounds tested. Liver damage is the principal toxic
effect. N-nitrosodiphenylamine, unlike many other N-nitroso-
amines, does not show mutagenic activity. N-nitrosodiphenylamine
has been reported by several investigations to be non-carcino-
genic. However, the compound is capable of trans-nitrosation and
could thereby convert other amines to carcinogenic N-nitroso-
amines. Sixty-seven of 87 N-nitrosoamines studied were reported
to have carcinogenic activity. No water quality criterion have
been proposed for N-nitrosodiphenylamine.
No data are available on the behavior of N-nitrosodiphenylamine
in a POTW. Biochemical oxidation of many of the toxic organic
pollutants have been investigated, at least in laboratory scale
studies, at concentrations higher than those expected to be con-
tained in most municipal wastewaters. General observations have
been developed relating molecular structure to ease of degrada-
tion for all the toxic organic pollutants. The conclusion
reached by study of the limited data is that biological treatment
produces little or no removal of N-nitrosodiphenylamine in a
POTW. No information is available regarding possible interfer-
ence by N-nitrosodiphenylamine in POTW processes, or on the
possible detrimental effect on sludge used to amend soils in
which crops are grown. However, no interference or detrimental
effects are expected because N-nitroso compounds are widely dis-
tributed in the soil and water environment, at low concentra-
tions, as a result of microbial action on nitrates and
nitrosatable compounds.
Phthalate Esters (66-71). Phthalic acid, or 1,2-benzene-
dicarboxylic acid, is one of three isomeric benzenedicarboxylic
acids produced by the chemical industry. The other two isomeric
forms are called isophthalic and terephthalic acids. The formula
for all three acids is C«H*(COOH)2. Somes 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 one billion pounds. They are used as plasti-
cizers - primarily in the production of polyvinyl chloride (PVC)
resins. The most widely used phthalate plasticizer is bis (2-
ethylhexyl) phthalate (66) which accounts for nearly one-third of
the phthalate esters produced. This particular ester is commonly
referred to as dioctyl phthalate (DOP) and should not be confused
with one of the less used esters, di-n-octyl phthalate (69),
which is also used as a plasticizer. In addition to these two
isomeric dioctyl phthalates, four other esters, also used
primarily as plasticizers, are designated as toxic pollutants.
They are: butyl benzyl phthalate (67), di-n-butyl phthalate
(68), diethyl phthalate (70), and dimethyl phthalate (71).
194
-------
Industrially, phthalate esters are prepared from phthalic anhy-
dride 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 concen-
trations 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 intermesh-
ing 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
Xu4.u i ir raw waste- In addition to their use as plasticizers,
phthalate esters are used in lubricating oils and pesticide car-
ri?us; t The?e 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 tox-
icity 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, spleen-
itis, 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 toxic pollutant esters
were included in the study. Phthalate esters do bioconcentrate
in fish. The factors, weighted for relative consumption of
195
-------
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. A chronic toxicity test with bis (2-
ethylhexyl) phthalate showed that significant reproductive
impairment occurred at 0.003 mg/1 in the freshwater crustacean,
Daphnia maqna. In acute toxicity studies, saltwater fish and
organisms showed sensitivity differences of up to eight-fold to
butyl benzyl, diethyl, and dimethyl phthalates. This suggests
that each ester must be evaluated individually for toxic effects.
The behavior of phthalate esters in a POTW has not been studied.
However, the biochemical oxidation of many of the toxic organic
pollutants has been investigated in laboratory scale studies at
concentrations higher than would normally be expected in munici-
pal wastewaters. Three of the phthalate esters were studed.
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 their removal by
biological treatment in a POTW is expected to occur to a moderate
degree. Using these data and other observations relating molecu-
lar structure to ease of biochemical degradation of other toxic
organic pollutants, the conclusion was reached that butyl benzyl
phthalate and dimethyl phthalate would be removed in a POTW to a
moderate degree by biological treatment. On the same basis, it
was concluded that di-n-octyl phthalate would be removed to a
slight degree or not at all. An EPA study of seven POTW facili-
ties revealed that for all but di-n-octyl phthalate, which was
not studied, removals ranged from 62 to 87 percent.
No information was found on possible interference with POTW oper-
ation or the possible effects on sludge by the phthalate esters.
The water insoluble phthalate esters - butyl benzyl 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-ethvlhexvl) 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 C6H4(COOC8H17)2. This toxic
pollutant constitutes about one-third of the phthalate ester
production in the U.S. It is commonly referred to as dioctyl
phthalate, or DOP, in the plastics industry where it is the most
196
-------
extensively used compound for the plasticization of polyvinyl
?u10™?€JPVC>> Bis(2-ethylhexyl) phthalate has been approved by
the FDA for use in plastics in contact with food. Therefore it
m?y t. *°"nd in wastewaters coming in contact with discarded
plastic food wrappers as well as the PVC films and shapes
normally found in industrial plants. This toxic pollutant is
also a commonly used organic diffusion pump oil, where its low
vapor pressure is an advantage.
u°r/^th?u P5ote?tion of human health from the toxic properties of
bis(2-ethylhexyl) phthalate ingested through water and through
contaminated aquatic organisms, the ambient water quality criter-
ion is determined to be 15 mg/1. If contaminated aquatic organ-
isms alone are consumed, excluding the consumption of water, the
ambient water criterion is determined to be 50 mg/1.
Although the behavior of bis(2-ethylhexyl) phthalate in a POTW
has not been studied, biochemical oxidation of this toxic pollu-
hf«K S been studied on a laboratory scale at concentrations
higher than would normally be expected in municipal wastewater
In.JfFesh water wlth a non-acclimated seed culture no biochemical
oxidation was observed after 5, 10, and 20 days. However, with
an acclimated seed culture, biological oxidation occured to the
extents of 13, 0, 6, and 23 percent of theoretical after 5, 10
15, and 20 days, respectively. Bis(2-ethylhexyl) phthalate
concentrations were 3 to 10 mg/1. Little or no removal of bis(2-
ethylhexyl) phthalate by biological treatment in a POTW is
expected.
Butyl benzyl phthalate (671. m addition to the general remarks
and discussion on phthalate esters, specific information 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.
Nu*.um^>i?nt water Duality criterion is proposed for butyl benzyl
pntnalate. •*
Butyl benzyl phthalate removal in a POTW by biological treatment
is expected to occur to a moderate degree.
Di-n-butvl phthalate (681. m addition to the general remarks
and discussion on phthalate esters, specific information on di-n-
butyl phthalate (DBP) is provided. DBP is a colorless? oil
197
-------
liquid, boiling at 340° C. Its water solubility at room tempera-
ture is reported to be 0.4 g/1 and 4.5 g/1 in two different
chemical hand books. The formula for DBF, C«H4(COOC4H9)Z, is the
same as for its isomer, di-isobutyl phthalate. DBF production is
1 to 2 percent of total U.S. phthalate ester production.
Dibutyl phthalate is used to a limited extent as a plasticizer
for polyvinyl chloride (PVC). It is not approved for contact
with food. It is used in liquid lipsticks and as a diluent for
polysulfide dental impression materials. DBF is used as a plas-
ticizer for nitrocellulose in making gun powder, and as a fuel in
solid propellants for rockets. Further uses are insecticides,
safety glass manufacture, textile lubricating agents, 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 quality 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 a 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 wastewaters. Biochemical
oxidation of 35, 43, and 45 percent of theoretical oxidation were
obtained after 5, 10, and 20 days, respectively, using sewage
microorganisms as an unacclimated seed culture.
Biological treatment in a POTW is expected to remove di-n-butyl
phthalate to a moderate degree.
Di-n-octvl ohthalate (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 mm Hg. It
is insoluble in water. Its molecular formula is C6H4(COOCeH17)2.
Its production constitutes about 1 percent of all phthalate ester
production in the U.S.
Industrially, di-n-octyl phthalate is used to plasticize poly-
vinyl chloride (PVC) resins.
No ambient water quality criterion is proposed for di-n-octyl
phthalate.
198
-------
Biological treatment in a POTW is expected to lead to little or
no removal of di-n-octyl phthalate.
Dimethyl phthalate (71). m addition to the general remarks and
^fhU?Si°n/^?h^halate esters' specific information on dimethyl
phthalate W- = 194 compared to M,W. of 391 for
bis(2-ethylhexyl) phthalate. DMP has a boiling point of 282<> c
It is a colorless liquid, soluble in water to the extent of 5
mg/i. its molecular formula is C6H4(COOCH2)Z.
Dimethyl phthalate production in the U.S. is just under one per-
cent of total phthalate ester production. DMP is used to some
extent as a plasticizer in cellulosics; however, its principal
2SS£ -° 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 case for long-life finishes for exterior metal siding. Coil
coating techniques are used to apply PVDF dispersions to aluminum
or galvanized steel siding.
tuh? Protection of human health from the toxic properties of
dimethyl phthalate ingested through water and through contami-
nated aquatic organisms, the ambient water criterion is deter-
mined to be 313 mg/1. if contaminated aquatic organisms alone
waterCcrlter?on
Based on limited data and observations relating molecular struc-
i? *.t0^ ea?e of biocnemical degradation of other toxic organic
pollutants, it is expected that dimethyl phthalate will be bio-
chemically oxidized to a lesser extent than domestic sewage by
biological treatment in a POTW.
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
neterocyclics, 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 toxic pollutants are listed with their
structural formula and melting point (m.p. ). All are nearly
insoluble in water. J
72 Benzo(a)anthracene ( 1 ,2-benzanthracene) m.p. 162° C
199
-------
7 3 Benzo{a)pyrene (3,4-benzopyrene)
m.p. 176<>
74 3,4-Benzofluoranthene
m.p. 168«> C
7 5 Benzo(k)f1uoranthene (11,12-benzof1uoranthene)
m.p. 2170
76 Chrysene (1,2-benzphenanthrene)
m.p.2550
77 Acenaphthylene
m.p. 92° C
HC-CH
78 Anthracene
m.p. 216° C
.OLOLO]
7 9 Benzo(gh i)pery1ene (1,12-benzopery1ene)
m.p. not reported
80 Fluorene (alpha-diphenylenemethane)
m.p. 116° C
(OTTO;
200
-------
81
Phenanthrene
m.p. 1010
82
Dibenzo(a,h)anthracene (1,2,5,6-
dibenzoanthracene)
83
Indeno (1,2,3-cd)pyrene
(2,3-o-phenylenepyrene)
84
Pyrene
m.p. 269°
m.p. not available
m.p. 156° C
Some of these toxic pollutants have commercial or industrial
uses. Benzo(a)anthracene, benzo(a)pyrene, chrysene, anthracene,
dibenzo(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 indus-
trial 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. Con-
sequently, 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 associ-
ated with specific individual compounds.
The screening and verification analysis procedures used for the
toxic organic 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 parameters of the
pair are not differentiated. For these three pairs anthracene
(78) - phenanthrene (81); 3,4-benzofluoranthene (74) - benzo(k)-
201
-------
fluoranthene (75); and benzo(a)anthracene (72) - chrysene (76)
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.
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
dermal 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 non-carcinogenic PAH compounds.
Because there were no studies available regarding chronic oral
exposures to PAH mixtures, proposed water quality criteria were
derived using data on exposure to a single compound. Two studies
were selected, one involving benzo(a)pyrene ingestion and one
involving dibenzo(a,h)anthracene ingestion. Both are known
animal carcinogens.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to polynuclear aromatic
hydrocarbons (PAH) through ingestion of water and contaminated
aquatic organisms, the ambient water concentration is zero.
Concentrations of PAH estimated to result in additional risk of 1
in 100,000 were derived by the EPA and the Agency is considering
setting criteria at an interim target risk level in the range of
10-7, 10-*, or 10~5 with corresponding criteria of 0.00000028
mg/1, 0.0000028 mg/1, and 0.000028 mg/1, respectively.
No standard toxicity tests have been reported for freshwater or
saltwater organisms and any of the 13 PAH discussed here.
The behavior of PAH in a 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 bac-
terial 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 biochemical oxi-
202
-------
dation 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 toxic organic 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 all by biological treatment methods in a POTW.
The most recent EPA study of POTW removal of toxic organics
indicates that anthracene is 70 percent removed by POTWs and
phenanthrene is 73 percent removed by POTWs.
No data are available at this time to support any conclusions
about contamination of land by PAH on which sewage sludge con-
taining PAH is spread.
Tetrachloroethvlene (85). Tetrachloroethylene (CCla CC12), 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 20°
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 concen-
tration. 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 suggests, but does not con-
clude, that PCE is teratogenic. PCE has been demonstrated to be
a liver carcinogen in B6C3-F1 mice.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to tetrachlorethylene through
ingestion of water and contaminated aquatic organisms, the ambi-
ent water concentration is zero. Concentrations of tetrachloro-
ethylene estimated to result in additional lifetime cancer risk
levels of 10-7, io-«, and 10-s are 0.00008 rng/1, 0.0008 mg/1, and
0.008 mg/1, respectively.
203
-------
No data were found regarding the behavior of PCE in a POTW. Many
of the toxic organic 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 toxic organic pollutants. The
conclusions reached by the study of the limited data is that
biological treatment produces a moderate removal of PCE in a POTW
by degradation. No information was found to indicate that PCE
accumulates in the sludge, but some PCE is expected to be
adsorbed onto settling particles. Some 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 occurring 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 phenyImethane. It is an aromatic hydrocarbon with the
chemical formula C«HSCH3. 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 two million metric tons. 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 anually 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 morphol-
ogy of major organs. The effects of inhaled toluene on the cen-
tral nervous system, both at high and low concentrations, have
been studied in humans and animals. However, ingested toluene is
expected to be handled differently by the body because it is
absorbed 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 prod-
ucts of toluene is benzoic acid, which itself seems to have
little potential to produce tissue injury.
Toluene does not appear to be teratogenic in laboratory animals
or man. Nor is there any conclusive evidence that toluene is
204
-------
mutagenic. Toluene has not been demonstrated to be positive in
a"y in vitro mutagenicity or carcinogenicity bioassay system, nor
to be carcinogenic in animals or man. y=>«™,
Mnv ~ in fisn caught in harbor waters ^ the
oi i" yh Petr°Jeum and petrochemical plants. Bioconcentration
studies have not been conducted, but bioconcentrat ion factors
d °n the baSlS °f the octanol-water paruuon
For the protection of human health from the toxic properties of
a±n?Lcln^Stedu.tnf°Ugh water and tnrough contaminated aquatic
organisms, the ambient water criterion is determined to be 14 3
2yri,',Hi™ i-v, aminaB':d afigniflCa?4y ,more resistant thiTTish. No test results
f«hub? ffeported for tne chronic effects of toluene on
freshwater fish or invertebrate species.
The biochemical oxidation of many of the toxic pollutants has
SaterVeth^atth0^ labora^7 scai* ^dies at ^oncen'rations
waltewat^r^ ^ ? ? expected to be contained by most municipal
^ K® : *fc ^oluene concentrations ranging from 3 to 250
mg/i biochemical oxidation proceeded to 50 percent of theoreti-
cal or greater. The time period varied from a few hours to 20
°r "° the Seed culture was acclimated.
=^ *!!?* t?10606 wiH ^ biochemically oxidized to a
POTW The v^M^tT domestiC1S!Wag? by bi°logical treatment in a
POTW. The volatility and relatively low water solubility of
rP±2Vle?d. to. the ««P*=tatlon that aeration processes win
remove significant quantities of toluene from the POTW. The EPA
studied toluene removal in seven POTW facilities. The removals
% v?s-tJ-,.g«,f-srffi!s-1g ss r
POTW removal of toxic organics indicates that toluene is
approximatley 70 percent removed. toluene is
Trichloroethylene UTJ.. Trichloroethylene (112-
y
87C °r S a Cear' col^l^siiquid boilng at
and is ^l?nhMv vaP°r Pressure of 77 mm Hg at room temperature
oreater i-Si^n J? S°iV^le in. W?ter (1 W1 > • U'S- Production is
greater than 0.25 million metric tons annually, it is produced
205
-------
from tetrachloroethane by treatment with lime in the presence of
water.
TCE is used for vapor phase degreasing of metal parts, cleaning
and drying electronic components, as a solvent for paints, as a
refrigerant, for extraction of oils, fats, and waxes, and for dry
cleaning. Its widespread use and relatively high volatility
result in detectable levels in many parts of the environment.
Data on the effects produced by ingested TCE are limited. Most
studies have been directed at inhalation exposure. Nervous sys-
tem disorders and liver damage are frequent results of inhalation
exposure. In the short term exposures, TCE acts as a central
nervous system depressant - it was used as an anesthetic before
its other long term effects were defined.
TCE has been shown to induce transformation in a highly sensitive
in vitro Fischer rat embryo cell system (F1706) that is used for
identifying carcinogens. Severe and persistent toxicity to the
liver was recently demonstrated when TCE was shown to produce
carcinoma of the liver in mouse strain B6C3F1. One systematic
study of TCE exposure and the incidence of human cancer was based
on 518 men exposed to TCE. The authors of that study concluded
that although the cancer risk to man cannot be ruled out, expo-
sure to low levels of TCE probably does not present a very
serious and general cancer hazard.
TCE is bioconcentrated in aquatic species, making the consumption
of such species by humans a significant source of TCE. For the
protection of human health from the potential carcinogenic
effects of exposure to trichloroethylene through ingestion of
water and contaminated aquatic organisms, the ambient water con-
centration should be zero based on the non-threshold assumption
of this chemical. However, zero level may not be attainable at
the present time. Therefore, the levels which may result in
incremental increase of cancer risk over the lifetime are
estimated at 10~5, 10~*, and 10~7. The corresponding recommended
criteria are 0.027 mg/1, 0.0027 mg/1, and 0.00027 mg/1.
Only a very limited amount of data on the effects of TCE on
freshwater aquatic life are available. One species of fish (fat-
head minnows) showed a loss of equilibrium at concentrations
below those resulting in lethal effects.
In laboratory scale studies of toxic organic pollutants, TCE was
subjected to biochemical oxidation conditions. After 5, 10, and
20 days no biochemical oxidation occurred. On the basis of this
study and general observations relating molecular structure-to
ease of degradation, the conclusion was reached that TCE would
undergo no removal by biological treatment in a POTW. The
206
-------
volatility and relatively low water solubility of TCE is expected
to result in volatilization of some of the TCE in aeration steps
in a POTW.
In addition, the lastest EPA study of POTW removal of toxic
organics indicates that trichloroethylene is 72 percent removed.
Antimony (114). Antimony (chemical name - stibium, symbol Sb),
classified as a non-metal 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 anti-
mony 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 opaci-
fier in glass, ceramics, and enamels. Several antimony compounds
are used as catalysts in organic chemicals synthesis, as fluori-
nating agents (the antimony fluoride), as pigments, and in fire-
works. Semiconductor applications are economically significant.
Essentially no information on antimony-induced human health
effects has been derived from community epidemiology studies.
The available data are in literature relating effects observed
with therapeutic or medicinal uses of antimony compounds a'nd
industrial exposure studies. Large therapeutic doses of anti-
monial compounds, usually used to treat schistisomiasis, 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 the 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 are consumed, excluding
the consumption of water, the ambient water criterion is deter-
mined 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 a POTW. The limited solubility of most antimony
compounds expected in a POTW, i.e., the oxides and sulfides, sug-
207
-------
gests 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 the effluent. Antimony compounds remaining in the
sludge under anaerobic conditions may be connected to stibine
(SbH3), 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 (115). Aresenic (chemical symbol As), is classified as a
non-metal or metalloid. Elemental arsenic normally exists in the
alpha-crystalline metallic form which is steel 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 gold ores. Arsenic is usually marketed
as the trioxide (As203). Annual U.S. production of the trioxide
approaches 40,000 tons.
The principal use of arsenic is in agricultural chemicals (herbi-
cides) for controlling weeds in cotton fields. Arsenicals have
various applications in medicinal and vetrinary 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 gastrointestinal
disturbances. Breakdown of red blood cells occurs. Symptoms of
acute poisoning include vomiting, diarrhea, abdominal pain,
lassitude, dizziness, and headache. Longer exposure produced
dry, falling hair, brittle, loose nails, eczema, and exfoliation.
Arsenicals also exhibit teratogenic and mutagenic effects in
humans. Oral administration of arsenic compounds has been
associated clinically with skin cancer for nearly one hundred
years. Since 1888 numerous studies have linked occupational
exposure and therapeutic administration 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 con-
centration is zero. Concentrations of arsenic estimated to
result in additional lifetime cancer risk levels of 10~7, 10~«,
and 10-s are 0.00000022 mg/1, 0.0000022 mg/1, and 0.000022 mg/1,
respectively. If containminated aquatic organisms alone are
consumed, excluding the consumption of water, the water
concentration should be less than 1.75 x 10-* to keep the
208
-------
increased lifetime cancer risk below 10~s. 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
a POTW. One EPA survey of nine POTW facilities reported influent
concentrations ranging from 0.0005 to 0.693 mg/1; effluents from
three POTW having biological treatment contained 0.0004 to 0.01
mg/1; two POTW facilities showed arsenic removal efficiencies of
50 and 71 percent in biological treatment. Inhibition of treat-
ment 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 facili-
ties, 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 plants can
take up arsenic, but normally their growth is inhibited before
the plants are ready for harvest.
Beryllium (117). Beryllium is a dark gray metal of the alkaline
earth family. It is relatively rare, but because of its unique
properties finds widespread use as an alloying element,
especially for hardening copper which is used in springs,
electrical contacts, and non-sparking tools. World production is
reported to be in the range of 250 tons annually. However, much
more reaches the environment as emissions from coal burning
operations. Analysis of coal indicates an average beryllium
content of 3 ppm and 0.1 to 1.0 percent in coal ash or fly ash.
The principle ores are beryl (3BeO.Al203.6Si02) and bertrandite
[Be6Si0207(OH2)]. Only two industrial facilities produce
beryllium in the U.S. because of limited demand and the highly
toxic character. About two-thirds of the annual production goes
into alloys, 20 percent into heat sinks, and 10 percent into
beryllium oxide (BeO) ceramic products.
Beryllium has a specific gravity of 1.846, making it the lightest
metal with a high melting point (1,350° C). Beryllium alloys are
corrosion resistant, but the metal corrodes in aqueous environ-
ments. Most common beryllium compounds are soluble in water, at
least to the extent necessary to produce a toxic concentration of
beryllium ions.
Most data on toxicity of beryllium are for inhalation of beryl-
lium oxide dust. Some studies on orally administered beryllium
in laboratory animals have been reported. Despite the large
number of studies implicating beryllium as a carcinogen, there is
no recorded instance of cancer being produced by ingestion. How-
ever, a recently convened panel of uninvolved experts concluded
209
-------
that epidemiologic evidence is suggestive that beryllium is a
carcinogen in man.
In the aquatic environment, beryllium is chronically toxic to
aquatic organisms at 0.0053 mg/1. Water softness has a large
effect on beryllium toxicity to fish. In soft water, beryllium
is reportedly TOO times as toxic as in hard water.
For the maximum production of human health from the potential
carcinogenic effects of exposure to beryllium through ingestion
of water and contaminated aquatic organisms, the ambient water
concentration is zero. Concentrations of beryllium estimated to
result in additional lifetime cancer risk levels of 10~7, 10-*,
and 10-5 are 0.00000037 mg/1, 0.0000037 mg/1, and 0.000037 mg/1,
respectively." If contaminated aquatic organisms alone are
consumed excluding the consumption of water, the concentration
should be less than 0.00117 mg/1 to keep the increased lifetime
cancer risk below 10~5.
Information on the behavior of beryllium in a POTW is scarce.
Because beryllium hydroxide is insoluble in water, most beryllium
entering a POTW will probably be in the form of suspended solids.
As a result, most of the beryllium will settle and be removed
with sludge. However, beryllium has been shown to inhibit sev-
eral enzyme systems, to interfere with DNA metabolism in liver,
and to induce chromosomal and mitotic abnormalities. This
interference in cellular processes may extend to interfere with
biological treatment processes. The concentration and effects of
beryllium in sludge which could be applied to cropland has not
been studied.
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 pro-
duction.
Cadmium is used primarily as an electroplated metal, and is found
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 through-
out the world. Cadmium may be a factor in the development of
such human pathological conditions as kidney disease, testicular
tumors, hypertension, arteriosclerosis, growth inhibition,
210
-------
chronic disease of old age, and cancer. Cadmium is normally
ingested by humans through food and water as well as by breathing
air contaminated 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 contaminated 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
molluscs, which accumulate cadmium in calcareous tissues and in
the viscera. A concentration factor of 1,000 for cadmium in fish
muscle has been reported, as have concentration factors of 3,000
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
mg/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 189 POTW facilities, 75 percent of the primary
plants, 57 percent of the trickling filter plants, 66 percent of
the activated sludge plants, and 62 percent of the biological
plants allowed over 90 percent of the influent cadmium to pass
through to the POTW effluent. Only two of the 189 POTW facili-
ties allowed less than 20 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
cadmium 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 cad-
mium, these contaminated crops could have a significant impact on
211
-------
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 300 mg/kg (dry basis) of cadmium mean « 10
mg/kg; median = 16 mg/kg. The USDA also recommends placing
limits on the total cadmium from sludge that may be applied to
land.
Chromium (119). Chromium is an elemental metal usually found as
a chromite (FeO.Crz03). The metal is normally produced by
reducing the oxide with aluminum. A significant proportion of
the chromium used is in the form of compounds such as sodium
dichromate (NajCrO*), and chromic acid (Cr03)-both are hexavalent
chromium compounds.
Chromium is found as an alloying component of many steels and its
compounds are used in electroplating baths, and as corrosion
inhibitors for closed water circulation systems.
The two chromium forms most frequently found in industry waste-
waters are hexavalent and trivalent chromium. Hexavalent chro-
mium 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 chro-
mium, and second to precipitate the trivalent form as the hydrox-
ide. 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 sensitiza-
tions. 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 chro-
mate ions that show no effect in man appear to be so low as to
prohibit determination, to date.
The toxicity of chromium salts to fish 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 to 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 and 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
212
-------
contaminated aquatic organisms, the ambient water quality crite-
rion is 170 mg/1. If contaminated aquatic organisms alone are
consumed, excluding the consumption of water, the ambient water
criterion for trivalent chromium is 3,433 mg/1. The ambient
water quality criterion for hexavalent chromium is recommended to
be identical to the existing drinking water standard for total
chromium which is 0.050 mg/1.
Chromium is not destroyed when treated by a POTW (although the
oxidation state may change), and will either pass through to the
POTW effluent or be incorporated into the POTW sludge. Both oxi-
dation states can cause POTW treatment inhibition and can also
limit the usefulness of municipal sludge.
Influent concentrations of chromium to POTW facilities have been
observed by EPA to range from 0.005 to 14.0 mg/1, with a median
concentration of 0.1 mg/1. The efficiencies for removal of chro-
mium by the activated sludge process can vary greatly, depending
on chromium concentration in the influent, and other operating
conditions at the POTW. Chelation of chromium by organic matter
and dissolution due to the presence of carbonates can cause
deviations from the predicted behavior in treatment systems.
The systematic presence of chromium compounds will halt nitrifi-
cation 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 tri-
valent chromium has little 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 micro-
organisms 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 POTW facilities, 56 percent of the primary plants
allowed more than 80 percent pass-through to POTW effluent. More
advanced treatment results in less pass-through. POTW 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 prob-
lems in uncontrolled landfills. Incineration, or similar
destructive oxidation processes, can produce hexavalent chromium
from lower valence states. Hexavalent chromium is potentially
213
-------
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 concentra-
tion of chromium in sludge. In Buffalo, New York, pretreatment
of electroplating waste resulted in a decrease in chromium con-
centrations in POTW sludge from 2,510 to 1,040 mg/kg. A similar
reduction occurred in Grand Rapids, Michigan, POTW facilities
where the chromium concentration in sludge decreased from 11,000
to 2,700 mg/kg when pretreatment was made a requirement.
Copper (120). Copper is a metallic element that sometimes is
found free, as the native metal, and is also found in minerals
such as cuprite (Cu20), malechite [CuC03.Cu(OH)2], azurite
[2CuC03.Cu(OH)2], chalcopyrite (CuFeS2), and bormite (CusFeS4).
Copper is obtained from these ores by smelting, leaching, and
electrolysis. It is used in the plating, electrical, plumbing,
and heating equipment industries, as well as in insecticides and
fungicides.
Traces of copper are found in all forms of plant and animal life,
and the metal is an essential trace element for nutrition.
Copper is not considered to be a cumulative systemic poison for
humans as-it is readily excreted by the body, but it can cause
symptoms of gastroenteritis, with nausea and intestinal irrita-
tions, at relatively low dosages. The limiting factor in domes-
tic water supplies is taste. To prevent this adverse organolep-
tic 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 chemi-
cal characteristics of the water, including temperature, hard-
ness, turbidity, and carbon dioxide content. In hard water, the
toxicity 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 0.03 mg/1 have proved 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 freshwater aquatic life is
0.0056 mg/1 as a 24-hour average, and 0.012 mg/1 maximum concen-
tration at a hardness of 50 mg/1 CaC03. For total recoverable
214
-------
copper the criterion to protect freshwater aquatic life is 0.0056
mg/1 as a 24-hour average.
Copper salts cause undesirable color reactions in the food indus-
try and cause pitting when deposited on some 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,
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 ppm. 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 concentra-
tions of copper in snapbean leaves and pods was less than 50 and
20 mg/kg, respectively, under conditions of severe copper toxic-
ity. 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 a POTW has been observed
by the EPA to range from 0.01 to 1.97 mg/1, with a median
concentration of 0.12 mg/1. The copper that is removed from the
influent stream of a POTW is absorbed on the sludge or appears in
the sludge as 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
to have severe effects on the removal efficiency of an
unacclimated system, 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 facilities, the median pass-through
was over 80 percent for primary plants and 40 to 50 percent for
trickling filter, activated sludge, and biological treatment
215
-------
plants. POTW effluent concentrations of copper ranged from 0.003
to 1.8 mg/1 (mean 0.126, standard deviation 0.242).
Copper which does not pass through the POTW will be retained in
the sludge where it will 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 mg/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 the tillage, except
for copper which is taken up by plants grown in the soil. Recent
investigation has shown that the extractable copper content of
s1udge-treated so i1 decreased with t ime, wh i ch suggests a
reversion of copper to less soluble forms was occurring.
Cyanide (121). 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
more toxic form of cyanide prevails.
Cyanide ions combine with numerous heavy metal ions to form com-
plexes. 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 com-
plexes is extremely variable. Those formed with zinc, copper,
and cadmium are not stable - they rapidly dissociate, with pro-
duction of HCN, in near neutral or acid waters. Some of the com-
plexes are extremely stable. Cobaltocyanide is very resistant to
acid distillation in the laboratory. Iron 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 cadmium
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 noncumulative
protoplasmic poisons. They arrest the activity of all forms of
216
-------
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
non-toxic thiocyanate and eliminate 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 concentration to a safe level.
Cyanides are more toxic to fish than to lower forms of aquatic
organisms such as midge larvae, crustaceans, and mussels. Toxic-
ity to fish is a function of chemical form 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 0.14 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 quality criterion is determined to
be 0.200 mg/1.
Persistence 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 com-
plete 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 may occur as part of a POTW treatment, or during the
disinfection treatment of surface water for drinking water prep-
aration.
Cyanides can interfere with treatment processes in a POTW, or
pass through to ambient waters. At low concentrations and with
acclimated microflora, cyanide may be decomposed by microorga-
nisms in anaerobic and aerobic environments or waste treatment
systems. However, data indicate that much of the cyanide intro-
duced passes through to the POTW effluent. The mean pass-through
of 14 biological plants was 71 percent. In a recent study of 41
POTW facilities 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.
217
-------
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, ductile, blueish-gray,
metallic element, usually obtained from the mineral galena (lead
sulfide, PbS), anglesite (lead sulfate, PbS04), or cerussite
(lead carbonate, PbC03). Because it is usually associated 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 teratogenic in experi-
mental animals. Mutagenicity data are not available for lead.
The ambient water quality criterion for lead is recommended to be
identical to the existng drinking water standard which 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 of total
recoverable lead as a 24-hour average with a water hardness of 50
mg/1 as CaC03.
Lead is not destroyed in a 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 con-
centration 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 facilities, median pass through values were over 80
percent for primary plants and over 60 percent for trickling
218
-------
filter, activated sludge, and biological process plants. Lead
concentration in POTW effluents ranged from 0.003 to 1.8 mg/1
(mean = 0.106 mg/1, standard deviation = 0.222).
Application of lead-containing sludge to cropland should not lead
to uptake by crops under most conditions because normally lead is
strongly bound by soil. However, under the unusual condition of
low pH (less than 5.5) and low concentrations of labile phos-
phorus, lead solubility is increased and plants can accumulate
lead.
Mercury (123). Mercury is an elemental metal rarely found in
nature as the free metal. Mercury is unique among metals as it
remains a liquid down to about 39 degrees below zero. It is
relatively inert chemically and is insoluble in water. The
principal ore is cinnabar (HgS).
Mercury is used industrially as the metal and as mercurous and
mercuric salts and compounds. Mercury is used in several types
of batteries. Mercury released to the aqueous environment is
subject to biomethylation - conversion to the extremely toxic
methyl mercury.
Mercury can be introduced into the body through the skin and the
respiratory system as the elemental vapor. Mercuric salts are
highly toxic to humans and can be absorbed through the gastro-
intestinal tract. Fatal doses can vary from 1 to 30 grams.
Chronic toxicity of methyl mercury is evidenced primarily by
neurological symptoms. Some mercuric salts cause death by kidney
failure.
Mercuric salts are extremely toxic to fish and other aquatic
life. Mercuric chloride is more lethal than copper, hexavalent
chromium, zinc, nickel, and lead towards fish and aquatic life.
In the food cycle, algae containing mercury up to 100 times the
concentration in the surrounding sea water are eaten by fish
which further concentrate the mercury. Predators that eat the
fish in turn concentrate the mercury even further.
For the protection of human health from the toxic properties of
mercury ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determined to be
0.000144 mg/1.
Mercury is not destroyed when treated by a POTW, and will either
pass through to the POTW effluent or be incorporated into the
POTW sludge. At low concentrations it may reduce POTW removal
efficiencies, and at high concentrations it may upset the POTW
operation.
219
-------
The influent concentrations of mercury to POTW have been observed
by the EPA to range from 0.0002 to 0.24 mg/1, with a median con-
centration of 0.001 mg/1. Mercury has been reported in the
literature to have inhibiting effects upon an activated sludge
POTW at levels as low as 0.1 mg/1. At 5 mg/1 of mercury, losses
of COD removal efficiency of 14 to 40 percent have been reported.
Upset of an activated sludge POTW is reported in the literature
to occur near 200 mg/1. The anaerobic digestion process is much
less affected by the presence of mercury, with inhibitory effects
being reported at 1,365 mg/1.
In a study of 22 POTWs having secondary treatment, the range of
removal of mercury from the influent to the POTW ranged from 4 to
99 percent with median removal of 41 percent. Thus significant
pass through of mercury may occur.
In sludges, mercury content may be high if industrial sources of
mercury contamination are present. Little is known about the
form in which mercury occurs in sludge. Mercury may undergo
biological methylation in sediments, but no methylation has been
observed in soils, mud, or sewage sludge.
The mercury content of soils not receiving additions of POTW sew-
age sludge lie in the range from 0.01 to 0.5 mg/kg. In soils
receiving POTW sludges for protracted periods, the concentration
of mercury has been observed to approach 1.0 mg/kg. In the soil,
mercury enters into reactions with the exchange complex of clay
and organic fractions, forming both ionic and covalent bonds.
Chemical and microbiological degradation of mercurials can take
place side by side in the soil, the products - ionic or molecular
- are retained by organic matter and clay or may be volatilized
if gaseous. Because of the high affinity between mercury and the
solid soil surfaces, mercury persists in the upper layer of soil.
Mercury can enter plants through the roots, it can readily move
to other parts of the plant, and it has been reported to cause
injury to plants. In many plants mercury concentrations range
from 0.01 to 0.20 mg/kg, but when plants are supplied with high
levels of mercury, these concentrations can exceed 0.5 mg/kg.
Bioconcentration occurs in animals ingesting mercury in food.
Nickel (124). Nickel is seldom found in nature as the pure
elemental metal. It is a relatively 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)9Se], and a
lateritic ore consisting of hydrated nickel-iron-magnesium
silicate.
220
-------
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 of nickel to man is thought to be very low, and sys-
temic poisoning of human beings by nickel or nickel salts is
almost unknown. In non-human 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 is present in coastal and open ocean
water at concentrations in the range of 0.0001 to 0.006 mg/1
although the most common values are 0.002 to 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 0.0134
mg/1. If contaminated aquatic organisms are consumed, excluding
consumption of water, the ambient water criterion is determined
to be 0.100 mg/1. Available data show that adverse effects on
aquatic life occur for total recoverable nickel concentrations as
low as 0.0071 mg/1 as a 24-hour average.
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
significantly reduced normal treatment efficiencies for a few
hours, but the plant acclimated itself somewhat to the slug dos-
age and appeared to achieve normal treatment efficiencies within
40 hours. It has been reported that the anaerobic digestion pro-
cess is inhibited only by high concentrations of nickel, while a
low concentration of nickel inhibits the nitrification process.
The influent concentration of nickel to a POTW 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 facilities, 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
221
-------
effluent 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
environemntal exposures to nickel 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
materials 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 non-metallic
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.
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
222
-------
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, pulmonary
edema, and coma occurred. Selenium produces mutagenic and tera-
togenic 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 determined to be 0.010
mg/1/ i.e., the same as the drinking water standard. Available
data show that adverse effects on aquatic life occur at con-
centrations higher than that cited for human toxicity.
Very few data are available regarding the behavior of selenium in
a POTW. One EPA survey of 103 POTW facilities 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 facilities 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 mammals 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 (Ag2S), horn silver (AgCl), procisite (Ag,AsS,), and
pyrangyrite (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 sys-
tem and deposited in various body tissues, resulting in general-
ized or sometimes localized gray pigmentation of the skin and
mucous membranes known 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 0.000001 to
0.0005 mg/1 have been reported as sufficient to sterilize water.
The criterion for ambient water to protect human health from the
toxic properties of silver ingested through water and through
contaminated aquatic organisms is 0.050 mg/1.
223
-------
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 a 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 indica-
tion that silver could be bioaccumulated in mushrooms to the
extent that there could be adverse physiological effects on
humans if they consumed large quantities of mushrooms grown in
silver enriched soil. The effect, however, would tend to be
unpleasant rather than fatal.
There is little summary data available on the quantity of silver
discharged to a 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 commercial 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 1,500 pounds.
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.
224
-------
For the protection of human health from the toxic properties of
thallium ingested through water and contaminated aquatic
organisms, the ambient water criterion is 0.013 mg/1.
No reports were found regarding the behavior of thallium in a
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 a POTW may be pre-
cipitated 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 rela-
tively 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, silver-white metal. In addition to its use in alloys,
zinc is used as a protective coating on steel. It is applied by
hot diping (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 which persists through conventional treat-
ment. For the prevention of adverse effects due to these organo-
leptic properties of zinc, 5 mg/1 was adopted for the ambient
water criterion. Available data show that adverse effects on
aquatic life occur at concentrations as low as 0.047 mg/1 as a
24-hour average.
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 concen-
trations induce cellular breakdown of the gills, and possibly the
clogging of the gills with mucous. Chronically toxic concentra-
tions 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 zinc concentra-
tion, dissolved zinc concentration, pH, temperature, and calcium
and magnesium concentration. Prediction of harmful effects has
225
-------
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 sub-
lethal effects of the metallic compounds and complexes. Zinc
accumulates in some marine species, and marine animals contain
zinc in the range of 6 to 1,500 mg/kg. From the point of view of
acute lethal effects, invertebrate marine animals seem to be the
most sensitive organism tested.
Toxicities of zinc in nutrient solutions have been demonstrated
for a number of plants. A variety of fresh water plants tested
manifested harmful symptoms at concentrations of 0.030 to 21.6
mg/1. Zinc sulfate has also been found to be lethal to many
plants and it could impair agricultural uses of the water.
Zinc is not destroyed when treated by a POTW, but will either
pass through to the POTW effluent or be retained in the POTW
sludge. It can interfere with treatment processes in the POTW
and can also limit the usefulness of municipal sludge.
In slug doses, and particularly in the presence of copper, dis-
solved zinc can interfere with or seriously disrupt the operation
of POTW biological processes by reducing overall removal effi-
ciencies, largely as a result of the toxicity of the metal to
biological organisms. However, zinc solids in the form of
hydroxides or sulfides do not appear to interfere with biological
treatment processes, on the basis of available data. Such solids
accumulate in the sludge.
The influent concentrations of zinc to a POTW has been observed
by the EPA to range from 0.017 to 3.91 mg/1, with a median con-
centration of 0.33 mg/1. Primary treatment is not efficient in
removing zinc; however, the microbial floe of secondary treatment
readily adsorbs zinc.
In a study of 258 POTW facilities, the median pass-through values
were 70 to 88 percent for primary plants, 50 to 60 percent for
trickling filter and biological process plants, and 30 to 40 per-
cent for activated process plants. POTW effluent concentrations
of zinc ranged from 0.003 to 3.6 mg/1 (mean = 0.330, standard
deviation = 0.464).
The zinc which does not pass through the POTW is retained in the
sludge. The presence of zinc in sludge may limit its use on
cropland. Sewage sludge contains 72 to over 30,000 mg/kg of
zinc, with 3,366 mg/kg as the mean value. These concentrations
are significantly greater than those normally found in soil,
which range from 0 to 195 mg/kg, with 94 mg/kg being a common
226
-------
level. Therefore, application of sewage sludge to soil will
generally increase the concentration of zinc in the soil. Zinc
can be toxic to plants, depending upon soil pH. Lettuce, toma-
toes, turnips, mustard, kale, and beets are especially sensitive
to zinc contamination.
Oil, and Grease. Oil and grease are taken together as one
pollutant parameter. This is a conventional pollutant and some
of its components are:
1. Light Hydrocarbons - These include light fuels such as
gasoline, kerosene, and jet fuel, and miscellaneous solvents
used for industrial processing, degreasing, or cleaning
purposes. The presence of these light hydrocarbons 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
into two classes: non-emulsifiable oils such as lubricating
oils and greases and emulsifiable oils such as water soluble
oils, rolling oils, cutting oils, and drawing 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 water.
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 emul-
sions 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 toxic organic pollutants will be found distributed
between the oil phase and the aqueous phase in industrial waste-
waters. The presence of phenols, PCB's, PAH's, and almost any
other organic pollutant in the oil and grease make characteriza-
tion of this parameter almost impossible. However, all of these
227
-------
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 susceptibil-
ity. However, it has been reported that crude oil in concentra-
tions as low as 0.3 mg/1 is extremely toxic to freshwater 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 concentra-
tions of oil and grease interfere with biological treatment
processes. The oils coat surfaces and solid particles, prevent-
ing 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.
EH. Although not a specific pollutant, pH is related to the
acidity or alkalinity of a wastewater stream. It is not, how-
ever, a measure of either. The term pH is used to describe the
hydrogen ion concentration (or activity) present in a given solu-
tion. 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 alka-
line, 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 deter-
mining necessary measures for corrosion control, sanitation, and
disinfection. Its value is also necessary in the treatment of
industrial wastewaters to determine amounts of chemicals required
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 struc-
tures, distribution lines, and household plumbing fixtures and
can thus add constituents to drinking water such as iron, copper,
zinc, cadmium, 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 providing safe drinking water.
228
-------
Extremes of pH or rapid pH changes can exert stress conditions or
Kill aquatic life outright. Even moderate changes from accept-
able criteria limits of pH are deleterious to some species.
The relative toxicity to aquatic life of many materials is
increased by changes in the water pH. For example, metallocya-
nide 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 to 9} is generally desired because either extreme beyond this
range has a deleterious effect on receiving waters or the pollu-
tant nature of other wastewater constituents.
Pretreatment for regulation of pH is covered by the "General Pre-
treatment Regulations for Existing and New Sources of Pollution "
40 CFR 403.5. This section prohibits the discharge to a POTW of
JwAu ?n^s which wil1 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."
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 materi-
als 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 decom-
posable substances. While in suspension, suspended solids
increase the turbidity of the water, reduce light penetration,
and impair the photosynthetic activity of aquatic plants.
Suspended solids in water interfere with many industrial pro-
cesses and cause foaming in boilers and incrustations on equip-
ment exposed to such water, especially as the temperature rises.
Tney are undesirable in process water used in the manufacture of
steel, in the textile industry, in laundries, in dyeing, and in
cooling systems. y'
Solids in suspension are aesthetically displeasing. When they
settle to form sludge deposits on the stream or lake bed, thev
are often damaging to the life in the water. Solids, when trans-
formed to sludge deposit, may do a variety of damaging things,
including blanketing the stream or lake bed and thereby destroy-
ing the living spaces for those benthic organisms that would
otherwise occupy the habitat. When of an organic nature, solids
229
-------
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 respira-
tory 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 com-
patible with a well-run POTW. This pollutant, with the exception
of those components which are described elsewhere in this sec-
tion, 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.
POLLUTANT SELECTION FOR COPPER FORMING WASTE STREAMS
The pollutant selection procedure was performed for the following
copper forming waste streams to select those toxic pollutants
that would be considered for establishing regulations for the
Copper Forming Category:
Cold Rolling Spent Lubricant
Hot Rolling Spent Lubricant
Drawing Spent Lubricant
Solution Heat Treatment Contact Cooling Water
Extrusion Press Heat Treatment Contact Cooling Water
Pickling Bath
Pickling Rinse
Alkaline Cleaning Bath
Alkaline Cleaning Rinse
Annealing With Water
Annealing With Oil
Pickling Fume Scrubber Water
Surface Coating
Tumbling or Burnishing
Miscellaneous Waste Streams
Pollutants Not Detected. The toxic pollutants listed in Table
Vi-i were not detected in any samples from these wastewater
streams as reported in Tables V-15 through V-26 (pp. 107-147);
230
-------
therefore, they were not selected for consideration in establish-
ing regulations. Some pollutants marked with an asterisk were
possibly detected at levels below the quantification level.
Pollutants Detected but Present at Concentrations too Small to be
Treated. The two pollutants listed in Table VI-lTwere detected
in copper forming wastewater; however, they were found at
concentrations which were not treatable. Therefore, they were
not selected for consideration in establishing regulations.
Pollutants Which Will be Adequately Controlled by the Technolo-
2i§s Ufion Which This Regulation is Based. The iTT pollutants
f ? uJn Ie VI~3 were found in c°PPer forming wastewater at
treatable concentrations; however, it is not necessary to regu-
late them because they will be adequately controlled by the
technologies upon which the regulation is based.
Pollutants Detected in the Effluent of Only One Plant. The
pollutant listed in Table VI-4 was "detected"" 5bov¥ its
quantifiable level in the effluent from only one plant. It is
believed to be uniquely related to that plant and not related to
the manufacturing process under study.
Pollutants Selected for Regulation. The 17 toxic pollutants
listed in Table VI-5 were those not eliminated from consideration
for any of the reasons listed above; therefore, each was selected
ror consideration in establishing regulations.
The maximum concentrations of these toxic pollutants which are
being regulated are presented in Table VI-6.
231
-------
Table VI-1
POLLUTANTS NOT DETECTED IN COPPER FORMING WASTEWATER
1. acenaphthene
2. aerolein
3. aerylonitrlie
5. benzidine
6. carbon tetrachloride*
7. chlorobenzene*
8. 1,2,4-trichlorobenzene
9. hexachlorobenz ene
10. 1 ,2-dichloroethane
12. hexachloroethane
13. 1,1-dichloroethane
14. 1,1,2-trichloroethane
15. 1,1,2,2-tetrachloroethane
16. chloroethane
17. deleted
18. bis(chloroethyl)ether
19. 2-chloroethyl vinyl ether
20. 2-chloronaphthalene
21. 2,4,6-trichlorophenol
22. p-chloro-m-cresol
24. 2-chloropheno1
25. 1,2-dichlorobenzene
26. 1 ,3-dichlorobenzene
27. 1,4-dichlorobenzene
28. 3,3'-dichlorobenzidine
29. 1,1-dichloroethylene
30. 1 ,2-trans-dichloroethylene
31. 2,4-dichlorophenol
32. 1,2-dichloropropane
33. 1,3-dichloropropylene
34. 2,4-dimethylphenol
35. 2,4-dinitrotoluene
37. 1,2-diphenylhydrazine
39. fluoranthene
40. 4-chlorophenyl phenyl ether
41. 4-bromophenyl phenyl ether
42. bis(2-chloroisopropyl)ether
43. bis(2-chloroethoxy)methane
45. methyl chloride (chloromethane)
46. methyl bromide (bromomethane)
47. bromoform (tribromomethane)
48. dichlorobromomethane
49. deleted
50. deleted
51. chlorodibromomethane
232
-------
Table VI-1 (Continued)
POLLUTANTS NOT DETECTED IN COPPER FORMING WASTEWATER
52. hexachlorobutadiene
53. hexachlorocyclopentadiene
54. isophorone
56. nitrobenzene
57. 2-nitrophenol
58. 4-nitrophenol
59. 2,4-dinitrophenol
60. 4,6-dinitro-o-cresol
61. N-nitrosodimethylamine
63. N-nitrosodi-n-propylamine
64. pentachlorophenol
65. phenol
66. bis(2-ethylhexyl)phthalate*
67. butyl benzyl phthalate*
68. di-n-butyl phthalate*
69. di-n-octyl phthalate*
70. diethyl phthalate
71. dimethyl phthalate*
72. benzo(a)anthracene*
73. benzo(a)pyrene*
74. benzo(b)fluoranthene*
7 5. benzo(k)fluoranthene*
76. chrysene*
77. acenaphthylene*
79. benzo(ghi)perylene*
80. fluorene*
82. dibenzo(a,h)anthracene*
83. indeno(1,2,3-c,d)pyrene*
84. pyrene*
85. tetrachloroethylene*
88. vinyl chloride (chloroethylene)
89. aldrin
90. dieldrin
91. chlordane
92. 4,4'-DDT
93. 4,4'-DDE
94. 4,4'-DDD
95. alpha-endosulfan
96. beta-endosulfan
97. endosulfan sulfate
98. endrin
99. endrin aldehyde
100. heptachlor
101. heptachlor epoxide
102. alpha-BHC
233
-------
Table VI-1 (Continued)
POLLUTANTS NOT DETECTED IN COPPER FORMING WASTEWATER
103. beta-BHC
104. gamma-BHC
105. delta-BHC
106. PCB-1242 (a)
107. PCB-1254 (a)
108. PCB-1221 (a)
109. PCB-1232 (a)
110. PCB-1248 (b)
111 . PCB-1260 (b)
112. PCB-1016 (b)
113. toxaphene
116. asbestos (fibrous)
129. 2,3,7,8-tetrachlorodibenzo-p-dioxin
*Possibly detected, but below the analytical quantification
level.
(a) (b) Phenanthrene and anthracene are reported together since
they are not physically distinguishable using approved
analytical methods.
234
-------
Table VI-2
POLLUTANTS EXCLUDED FROM REGULATION BECAUSE
THEY ARE PRESENT IN AMOUNTS TOO SMALL
TO BE EFFECTIVELY TREATED
123. Mercury
127. Thallium
Table VI-3
POLLUTANTS EXCLUDED FROM REGULATION BECAUSE
THEY WILL BE EFFECTIVELY CONTROLLED BY THE
TECHNOLOGIES UPON WHICH THIS REGULATION IS BASED
114. Antimony
115. Arsenic
117. Beryllium
118. Cadmium
125. Selenium
126. Silver
Table VI-4
POLLUTANTS DETECTED IN THE EFFLUENT OF
ONLY ONE PLANT
121. cyanide
235
-------
Table VI-5
TOXIC POLLUTANTS REGULATED
4. Benzene
11. 1,1,1-Trichloroethane
23. Chloroform
36. 2,6-Dinitrotoluene
38. Ethylbenzene
44. Methylene Chloride
55. Naphthalene
62. N-Nitrosodiphenylamine
78. Anthracene
81. Phenanthrene
86. Toluene
87. Trichloroethylene
119. Chromium
120. Copper
122. Lead
124. Nickel
128. Zinc
236
-------
Table VI-6
MAXIMUM CONCENTRATIONS OF TOXIC POLLUTANTS
FOUND IN COPPER FORMING WASTEWATERS
Toxic Pollutant
4. Benzene
11. 1,1,1-Trichloroethane
23. Chloroform
36. 2,6-Dinitrotoluene
38. Ethylbenzene
44. Methylene Chloride
55. Naphthalene
62. N-Nitrosodiphenylamine
78. Anthracene (a)
81. Phenanthrene (a)
86. Toluene
87. Trichloroethylene
114. Ant imony
115. Arsenic
117. Beryllium
118. Cadmium
119. Chromium
120. Copper
121. Cyanide
122. Lead
123. Mercury
124. Nickel
128. Zinc
Maximum Concentration
Observed (mg/1)
2.0
0.087
0.038
14.0
0.043
0.053
3.5
90
27
27
0.057
0.023
2.26
0.80
0.0118
2.83
174
24,000
0.18
167
0.0024
385
45,000
(a) Phenanthrene and anthracene are reported together since they
are not physically distinguishable using approved analytical
methods.
237
-------
238
-------
SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
This section describes the treatment techniques currently used or
available to remove or recover wastewater pollutants normally
generated by the copper forming industrial point source category.
Included are discussions of individual end-of-pipe treatment
technologies and in-plant technologies. These treatment technol-
ogies are widely used in many industrial categories and data and
information to support their effectiveness have been drawn from a
similarly wide range of sources and data bases.
END-OF-PIPE TREATMENT TECHNOLOGIES
In this section, individual recovery and treatment technologies
are described which are used or are suitable for use in treating
wastewater discharges from copper forming facilities. Each
description includes a functional description and discussions of
application and performance, advantages and limitations, opera-
tional factors {reliability, maintainability, solid waste
aspects), and demonstration status. The treatment processes
described include both technologies presently demonstrated within
the copper forming category, and technologies demonstrated in
treatment of similar wastes in other industries.
Copper forming wastewater streams characteristically contain
significant levels of toxic inorganics. Chromium, copper, lead,
nickel, and zinc are found in copper forming wastewater streams
at substantial concentrations. These toxic inorganic pollutants
constitute the most significant wastewater pollutants in this
category. In general, these pollutants are removed by precipita-
tion of metal hydroxides or carbonates utilizing the reaction
with lime, sodium hydroxide, or sodium carbonate.
Discussion of end-of-pipe treatment technologies is divided into
three parts: the major technologies, the effectiveness of major
technologies, and minor end-of-pipe technologies.
MAJOR TECHNOLOGIES
In Sections IX, X, XI, and XII, the rationale for selecting
treatment systems is discussed. The individual technologies used
in the system are described here. The major end-of-pipe technol-
ogies are: chemical reduction of hexavalent chromium, chemical
precipitation of dissolved metals, granular bed filtration, pres-
sure filtration, settling of suspended solids, skimming of oil,
chemical emulsion breaking, and thermal emulsion breaking. In
practice, precipitation of metals and settling of the resulting
precipitates is often a unified two-step operation. Suspended
239
-------
solids originally present in raw wastewaters are not appreciably
affected by the precipitation operation and are removed with the
precipitated metals in the settling operations. Settling opera-
tions can be evaluated independently of hydroxide or other chemi-
cal precipitation operations, but hydroxide and other chemical
precipitation operations can only be evaluated in combination
with a solids removal operation.
1 . Chemical Reduction o£ Chromium
Description of the Process. Reduction is a chemical reaction in
which electrons are transferred to the chemical being reduced
from the chemical initiating the transfer (the reducing agent).
Sulfur dioxide, sodium bisulfite, sodium metabisulf ite, and
ferrous sulfate form strong reducing agents in aqueous solution
and are often used in industrial waste treatment facilities for
the reduction of hexavalent chromium to the trivalent form. The
reduction allows removal of chromium from solution in conjunction
with other metallic salts by alkaline precipitation. Hexavalent
chromium is not precipitated as the hydroxide.
Gaseous sulfur dioxide is a widely used reducing agent and pro-
vides a good example of the chemical reduction process. Reduc-
tion using other reagents is chemically similar. The reactions
involved may be illustrated as follows:
+ 3H20 3H2S03
3H2S03 + 2H2Cr04 Cr2(S04)3 + 5H20
The above reactions are favored by low pH. A pH of from 2 to 3
is normal for situations requiring complete reduction. At pH
levels above 5, the reduction rate is slow. Oxidizing agents
such as dissolved oxygen and ferric iron interfere with the
reduction process by consuming the reducing agent.
A typical treatment consists of 45 minutes retention in a
reaction tank. The reaction tank has an electronic recorder-
controller device to control process conditions with respect to
pH and oxidation-reduction potential (ORP) . Gaseous sulfur
dioxide is metered to the reaction tank to maintain the ORP
within the range of 250 to 300 millivolts. Sulfuric acid is
added to maintain a pH level of from 1.8 to 2.0. The reaction
tank is equipped with a propeller agitator designed to provide
approximately one turnover per minute. Figure VII-1 shows a
continuous chromium reduction system.
Application and Performance. Chromium reduction is used in
copper forming for treating pickling baths and pickling rinses.
Cooling tower blowdown may also contain chromium as a biocide in
waste streams. A study of an operational waste treatment facil-
240
-------
ity chemically reducing hexavalent chromium has shown that a 99.7
percent reduction efficiency is easily achieved. Reduction fol-
lowed by chemical precipitation can achieve final concentrations
of 0.05 mg/lf and concentrations of 0.01 mg/1 are considered to
be attainable by properly maintained and operated equipment.
Advantages and Limitations. The major advantage of chemical
reduction of hexavalent chromium is that it is a fully proven
technology based on many years of experience. Operation at
ambient conditions results in low energy consumption, and the
process, especially when using sulfur dioxide, is well suited to
automatic control. Furthermore, the equipment is readily obtain-
able from many suppliers, and operation is straightforward.
One limitation of chemical reduction of hexavalent chromium is
that for high concentrations of chromium, the cost of treatment
chemicals may be prohibitive. When this situation occurs, other
treatment techniques are likely to be more economical. Chemical
interference by oxidizing agents is possible in the treatment of
mixed wastes, and the treatment itself may introduce pollutants
if not properly controlled. Storage and handling of sulfur
dioxide is somewhat hazardous.
Operational Factors. Reliability: Maintenance consists of
periodic removal of sludge, the frequency of which is a function
of the input concentrations of detrimental constituents.
Solid Waste Aspects: Pretreatment to eliminate substances which
will interfere with the process may often be necessary. This
process produces trivalent chromium which can be controlled by
further treatment. There may, however, be small amounts of
sludge collected due to minor shifts in the solubility of the
contaminants. This sludge can be processed by the main sludge
treatment equipment.
Demonstration Status. The reduction of chromium waste by sulfur
dioxide or sodium bisulfite is a classic process and is used by
numerous plants which have hexavalent chromium compounds in
wastewaters from operations such as electroplating and coil
coating. Eight copper forming plants report the use of chromium
reduction to treat pickling wastewaters.
2. Chemical Precipitation
Dissolved toxic metal ions and certain anions may be chemically
precipitated for removal by physical means such as sedimentation,
filtration, or centrifugation. Several reagents are commonly
used to effect this precipitation.
241
-------
1. Alkaline compounds such as lime or sodium hydroxide may
be used to precipitate many toxic metal ions as metal
hydroxides. Lime also may precipitate phosphates as
insoluble calcium phosphate and fluorides as calcium
fluoride.
2. Both "soluble" sulfides such as hydrogen sulfide or
sodium sulfide and "insoluble" sulfides such as ferrous
sulfide may be used to precipitate many heavy metal
ions as insoluble metal sulfides.
3. Ferrous sulfate, zinc sulfate, or both (as required)
may be used to precipitate cyanide as a ferro or zinc
ferricyanide complex.
4. Carbonate precipitates may be used to remove metals
either by direct precipitation using a carbonate
reagent such as calcium carbonate or by converting
hydroxides into carbonates using carbon dioxide.
These treatment chemicals may be added to a flash mixer or rapid
mix tank, to a presettling tank, or directly to a clarifier or
other settling device. Because metal hydroxides tend to be col-
loidal in nature, coagulating agents may also be added to facili-
tate settling. After the solids have been removed, final pH
adjustment may be required to reduce the high pH created by the
alkaline treatment chemicals.
Chemical precipitation as a mechanism for removing metals from
wastewater is a complex process of at least two steps - precipi-
tation of the unwanted metals and removal of the precipitate.
Some small amount of metal will remain dissolved in the waste-
water after complete precipitation. The amount of residual
dissolved metal depends on the treatment chemicals used and
related factors. The effectiveness of this method of removing
any specific metal depends on the fraction of the specific metal
in the raw waste (and hence in the precipitate) and the effec-
tiveness of suspended solids removal. In specific instances, a
sacrificial ion such as iron or aluminum may be added to aid in
the precipitation process and reduce the fraction of a specific
metal in the precipitate.
Application and Performance. Chemical precipitation is used in
copper forming for precipitation of dissolved metals. It can be
used to remove metal ions such as antimony, arsenic, beryllium,
cadmium, chromium, cobalt, copper, iron, lead, manganese,
mercury, molybdenum, tin, and zinc. The process is also
applicable to any substance that can be transformed into an
insoluble form such as fluorides, phosphates, soaps, sulfides.
242
-------
and others. Because it is simple and effective, chemical
precipitation is extensively used for industrial waste treatment.
The performance of chemical precipitation depends on several
variables. The most important factors affecting precipitation
effectiveness are:
1. Maintenance of an alkaline pH throughout the
precipitation reaction and subsequent settling,
2. Addition of a sufficient excess of treatment ions to
drive the precipitation reaction to completion,
3. Addition of an adequate supply of sacrificial ions
(such as iron or aluminum) to ensure precipitation and
removal of specific target ions, and
4. Effective removal of precipitated solids (see
appropriate technologies discussed under "Solids
Removal").
Control of pH. Irrespective of the solids removal technology
employed, proper control of pH is absolutely essential for favor-
able performance of precipitation-sedimentation technologies.
This is clearly illustrated by solubility curves for selected
metals hydroxides and sulfides shown in Figure VII-2, and by
plotting effluent zinc concentrations against pH as shown in
Figure VII-3. Figure VII-3 was obtained from Development
Document for the Proposed Effluent Limitations Guidelines and New
Source Performance Standards for the Zinc Segment of Nonferrous
Metals Manufacturing Point Source Category, U.S. E.P.A., EPA
440/1-74/033, November, 1974. Figure VII-3 was plotted from the
sampling data from several facilities with metal finishing
operations. It is partially illustrated by data obtained from
three consecutive days of sampling at one metal processing plant
(47432) as displayed in Table VII-1. Flow through this system is
approximately 49,263 1/hr (13,000 gal/hr).
This treatment system uses lime precipitation (pH adjustment)
followed by coagulant addition and sedimentation. Samples were
taken before (in) and after (out) the treatment system. The best
treatment for removal of copper and zinc was achieved on day one,
when the pH was maintained at a satisfactory level. The poorest
treatment was found on the second day, when the pH slipped to an
unacceptably low level and intermediate values were achieved on
the third day, when pH values were less than desirable but in
between the first and second days.
Sodium hydroxide is used by one facility (plant 439) for pH
adjustment and chemical precipitation, followed by settling
243
-------
(sedimentation and a polishing lagoon) of precipitated solids.
Samples were taken prior to caustic addition and following the
polishing lagoon. Flow through the system is approximately
22,700 1/hr (6,000 gal/hr). Metals removal data for this system
are presented in Table VI1-2.
These data indicate that the system was operated efficiently.
Effluent pH was controlled within the range of 8.6 to 9.3, and
while raw waste.loadings were not unusually high, most toxic
metals were removed to very low concentrations.
Lime and sodium hydroxide are sometimes used to precipitate
metals. Data developed from plant 40063, a facility with a
metal-bearing wastewater, exemplify efficient operation of a
chemical precipitation and settling system. Table VII-3 shows
sampling data from this system, which uses lime and sodium
hydroxide for pH adjustment, chemical precipitation, polyelec-
trolyte flocculant addition, and sedimentation. Samples were
taken of the raw waste influent to the system and of the
clarifier effluent. Flow through the system is approximately
19,000 1/hr (5,000 gal/hr).
At this plant, effluent TSS levels were below 15 mg/1 on each
day, despite average raw waste TSS concentrations of over 3,500
mg/1. Effluent pH was maintained at approximately 8, lime addi-
tion was sufficient to precipitate the dissolved metal ions, and
the flocculant addition and clarifier retention served to remove
effectively the precipitated solids.
Sulfide precipitation is sometimes used to precipitate metals
resulting in improved metals removals. Most metal sulfides are
less soluble than hydroxides and the precipitates are frequently
more effectively removed from water. Solubilities for selected
metal hydroxide, carbonate, and sulfide precipitates are shown in
Table VII-4 (Source: Lanqe's Handbook of Chemistry). Sulfide
precipitation is particularly effective in removing specific
metals such as silver and mercury. Sampling data from three
industrial plants using sulfide precipitation appear in Table
VI1-5. The data were obtained from three sources:
1. Summary Report, Control and Treatment Technology for
the Metal Finishing Industry; Sulfide Precipitation,
U.S. EPA, EPA No. 625/8/80-003, 1979.
2. Industry Finishing, Vo. 35, No. 11, November, 1979.
3. Electroplating sampling data from plant 27045.
244
-------
In all cases except iron, effluent concentrations are below 0.1
mg/1 and in many cases below 0.04 mg/1 for the three plants
studied.
Sampling data from several chlorine-caustic manufacturing plants
using sulfide precipitation demonstrate effluent mercury concen-
trations varying between 0.009 and 0.03 mg/1. As shown in Figure
VII-2, the solubilities of PbS and Ag2S are lower at alkaline pH
levels than either of the corresponding hydroxides or other
sulfide compounds. This implies that removal performance for
lead and silver sulfides should be comparable to or better than
that for the heavy metal hydroxides. Bench scale tests on
several types of metal finishing and manufacturing wastewater
indicate that metals removal to levels of less than 0,05 mg/1 and
in some cases less than 0.01 mg/1 are common in systems using
sulfide precipitation followed by clarification. Some of the
bench scale data, particularly in the case of lead, do not
support such low effluent concentrations. However, lead is
consistently removed to very low levels (less than 0.02 mg/1) in
systems using hydroxide and carbonate precipitation and
sedimentation.
Of particular interest is the ability of sulfide to precipitate
hexavalent chromium (Cr+6) without prior reduction to the tri-
valent state as is required in the hydroxide process. When fer-
rous sulfide is used as the precipitant, iron and sulfide act as
reducing agents for the hexavalent chromium according .to the
reaction:
Cr03 + FeS + 3H20 - > Fe (OH)3 + Cr (OH)3 + S
The sludge produced in this reaction consists mainly of ferric
hydroxides, chromic hydroxides, and various metallic sulfides.
Some excess hydroxyl ions are generated in this process, possibly
requiring a downward readjustment of pH.
Based on the available data. Table VII-6 shows the minimum relia-
bly attainable effluent concentrations for sulfide precipitation-
sedimentation systems. These values are used to calculate
performance predictions of sulfide precipitation-sedimentation
systems. Table VII-6 is based on two reports:
1. Summary Report, Control and Treatment Technology for
the Metal Finishing Industry: Sulfide Precipitation,
U.S. EPA, EPA No. 625/8/80-003, 1979.
2. Addendum to Development Document for Effluent
Limitations Guidelines and New Source Performance
Standards, Major Inorganic Products Segment of
245
-------
Inorganics Point Source Category, U.S. EPA, EPA
Contract No. EPA/68-01-3281 (Task 7), June, 1978.
Carbonate precipitation is sometimes used to precipitate metals,
especially where precipitated metals are to be recovered. The
solubility of most metal carbonates is intermediate between
hydroxide and sulfide solubilities; in addition, carbonates form
easily filtered precipitates.
Carbonate ions appear to be particularly useful in precipitating
lead and antimony. Sodium carbonate has been observed being
added at treatment to improve lead precipitation and removal in
some industrial plants. The lead hydroxide and lead carbonate
solubility curves displayed in Figure VI1-4 {"Heavy Metals
Removal," by Kenneth Lanovette, Chemical Engineering/Deskbook
Issue, Oct. 17, 1977) explain this phenomenon.
Co-precipitation with Iron - The presence of substantial
quantities of iron in metal-bearing wastewaters before treatment
has been shown to improve the removal of toxic metals. In some
cases this iron is an integral part of the industrial wastewater;
in other cases iron is deliberately added as a preliminary or
first step of treatment. The iron functions to improve toxic
metal removal by three mechanisms: the iron co-precipitates with
toxic metals forming a stable precipitate which desolubilizes the
toxic metal; the" iron improves the settleability of the
precipitate; and the large amount of iron reduces the fraction of
toxic metal in the precipitate. Co-precipitation with iron has
been practiced for many years incidentally when iron was a
substantial constituent of raw wastewater and intentionally when
iron salts were added as a coagulant aid. Aluminum or mixed
iron-aluminum salts also have been used.
Co-precipitation using large amounts of ferrous iron salts is
known as ferrite co-precipitation because magnetic iron oxide or
ferrite is formed. The addition of ferrous salts (sulfate) is
followed by alkali precipitation and air oxidation. The resul-
tant precipitate is easily removed by filtration and may be
removed magnetically. Data illustrating the performance of
ferrite co-precipitation are shown in Table VI1-7. The data are
from:
Sources and Treatment of Wastewater in the Nonferrous Metals
Industry, U.S. EPA, EPA No. 600/2-80-074, 1980.
Advantages and Limitations. Chemical precipitation has proven to
be an effective technique for removing many pollutants from
industrial wastewater. It operates at ambient conditions and is
well suited to automatic control. The use of chemical
precipitation may be limited because of interference by chelating
246
-------
agents, because of possible chemical interference of mixed
wastewaters and treatment chemicals, or because of the
potentially hazardous situation involved with the storage and
handling of those chemicals. Lime is usually added as a slurry
when used in hydroxide precipitation. The slurry must be kept
well mixed and the addition lines periodically checked to prevent
blocking of the lines, which may result from a buildup of solids.
Also, hydroxide precipitation usually makes recovery of the
precipitated metals difficult, because of the heterogeneous
nature of most hydroxide sludges.
The major advantage of the sulfide precipitation process is that
the extremely low solubility of most metal suIfides promotes very
high metal removal efficiencies; the sulfide process also has the
ability to remove chromates and dichromates without preliminary
reduction of the chromium to its trivalent state. In addition,
sulfide can precipitate metals complexed with most complexing
agents. The process demands care, however, in maintaining the pH
of the solution at approximately 10 in order to prevent the gen-
eration of toxic hydrogen sulfide gas. For this reason, ventila-
tion of the treatment tanks may be a necessary precaution in most
installations. The use of insoluble sulfides reduces the problem
of hydrogen sulfide evolution. As with hydroxide precipitation,
excess sulfide ion must be present to drive the precipitation
reaction to completion. Since the sulfide ion itself is toxic,
sulfide addition must be carefully controlled to maximize heavy
metals precipitation with a minimum of excess sulfide to avoid
the necessity of post treatment. At very high excess sulfide
levels and high pH, soluble mercury-sulfide compounds may also be
formed. Where excess sulfide is present, aeration of the efflu-
ent stream can aid in oxidizing residual sulfide to the less
harmful sodium sulfate (Na2S04). The cost of sulfide
precipitants is high in comparison with hydroxide precipitants,
and disposal of metallic sulfide sludges may pose problems. An
essential element in effective sulfide precipitation is the
removal of precipitated solids from the wastewater and proper
disposal in an appropriate site. Sulfide precipitation will also
generate a higher volume of sludge than hydroxide precipitation,
resulting in higher disposal and dewatering costs. This is
especially true when ferrous sulfide is used as the precipitant.
Sulfide precipitation may be used as a polishing treatment after
hydroxide precipitation-sedimentation. This treatment configura-
tion may provide the better treatment effectiveness of sulfide
precipitation while minimizing the variability caused by changes
in raw waste and reducing the amount of sulfide precipitant
required.
Operational Factors. Reliability: Alkaline chemical
precipitation is highly reliable, although proper monitoring and
247
-------
control are required. Sulfide precipitation systems provide
similar reliability.
Maintainability: The major maintenance needs involve periodic
upkeep of monitoring equipment, automatic feeding equipment,
mixing equipment, and other hardware. Removal of accumulated
sludge is necessary for efficient operation of precipitation-
sedimentation systems.
Solid Waste Aspects: Solids which precipitate out are removed in
a subsequent treatment step. Ultimately, these solids require
proper disposal.
Demonstration Status. Chemical precipitation of metal hydroxides
is a classic waste treatment technology used by most industrial
waste treatment systems. Chemical precipitation of metals in the
carbonate form alone has been found to be feasible and is
commercially used to permit metals recovery and water reuse.
Full scale commercial sulfide precipitation units are in
operation at numerous installations. As noted earlier,
sedimentation to remove precipitates is discussed separately.
Chemical precipitation is currently demonstrated at 36 copper
forming plants.
3. Granular Bed Filtration
Filtration occurs in nature as the surface ground waters are
cleansed by sand. Silica sand, anthracite coal, and garnet are
common filter media used in water treatment plants. These are
usually supported by gravel. The media may be used singly or in
combination. The multi-media filters may be arranged to maintain
relatively distinct layers by virtue of balancing the forces of
gravity, flow, and buoyancy on the individual particles. This is
accomplished by selecting appropriate filter flow rates (gpm/sq-
ft), media grain size, and density.
Granular bed filters may be classified in terms of filtration
rate, filter media, flow pattern, or method of pressurization.
Traditional rate classifications are slow sand, rapid sand, and
high rate mixed media. In the slow sand filter, flux or
hydraulic loading is relatively low, and removal of collected
solids to clean the filter is therefore relatively infrequent.
The filter is often cleaned by scraping off the inlet face (top)
of the sand bed. In the higher rate filters, cleaning is fre-
quent and is accomplished by a periodic backwash, opposite to the
direction of normal flow.
A filter may use a single medium such as sand or diatomaceous
earth (Figure VII-5a), but dual (Figure VII-5d) and mixed (multi-
ple) media (Figure VII-5e) filters allow higher flow rates and
248
-------
efficiencies. The dual media filter usually consists of a fine
bed of sand under a coarser bed of anthracite coal. The coarse
coal removes most of the influent solids, while the fine sanr1
performs a polishing function. At the end of the backwash, the
fine sand settles to the bottom because it is denser than the
coal, and the filter is ready for normal operation. The mixed
media filter operates on the same principle, with the finer,
denser media at the bottom and the coarser, less dense media at
the top. The usual arrangement is garnet at the bottom (outlet
end) of the bed, sand in the middle, and anthracite coal at the
top. Some mixing of these layers occurs and is, in fact,
desirable.
The flow pattern is usually top-to^bottom, but other patterns are
sometimes used. Upflow filters (Figure VII-5b) are sometimes
used, and in a horizontal filter the flow is horizontal. In a
biflow filter (Figure VII-5c), the influent enters both the top
and the bottom and exits laterally. The advantage of an upflow
filter is that with a downflow backwash the particles of a single
filter medium are distributed and maintained in the desired
coarse-to-fine (bottom-to-top) arrangement. The disadvantage is
that the bed tends to become fluidized, which lowers filtration
efficiency. The biflow design is an attempt to overcome this
problem.
The classic granular bed filter operates by gravity flow; how-
ever, pressure filters are fairly widely used. They permit
higher solids loadings before cleaning and are advantageous when
the filter effluent must be pressurized for further downstream
treatment. In addition, pressure filter systems are often less
costly for low to moderate flow rates.
Figure VII-6 depicts a high rate, dual media, gravity downflow
granular bed filter, with self-stored backwash. Both filtrate
and backwash are piped around the bed in an arrangement that per-
mits gravity upflow of the backwash, with the stored filtrate
serving as backwash. Addition of the indicated coagulant and
pplyelectrolyte usually results in a substantial improvement in
filter performance.
Auxiliary filter cleaning is sometimes employed in the upper few
inches of filter beds. This is conventionally referred to as
surface wash and is accomplished by water jets just below the
surface of the expanded bed during the backwash cycle. These
jets enhance the scouring action in the bed by increasing the
agitation.
An important feature for successful filtration and backwashing is
the underdrain. This is the support structure for the bed. The
underdrain provides an area for collection of the filtered water
249
-------
without clogging from either the filtered solids or the media
grains. In addition, the underdrain prevents loss of the media
with the water, and during the backwash cycle it provides even
flow distribution over the bed. Failure to dissipate the veloc-
ity head during the filter or backwash cycle will result in bed
upset and the need for major repairs.
Several standard approaches are employed for filter underdrains.
The simplest one consists of a parallel porous pipe imbedded
under a layer of coarse gravel and manifolded to a header pipe
for effluent removal. Other approaches to the underdrain system
are known as the Leopold and Wheeler filter bottoms. Both of
these incorporate false concrete bottoms with specific porosity
configurations to provide drainage and velocity head dissipation.
Filter system operation may be manual or automatic. The filter
backwash cycle may be on a timed basis, a pressure drop basis
with a terminal value which triggers backwash, or a solids carry-
over basis from turbidity monitoring of the outlet stream. All
of these schemes have been used successfully.
Application and Performance. Wastewater treatment plants often
use granular bed filters for polishing after clarification,
sedimentation, or other similar operations. Granular bed
filtration thus has potential application to nearly all
industrial plants. Chemical additives which enhance the upstream
treatment equipment may or may not be compatible with or enhance
the filtration process. Normal operation flow rates for various
types of filters are as follows:
Slow Sand 2.04 - 5.30 1/sq m-hr
Rapid Sand 40.74 - 51.48 1/sq m-hr
High Rate Mixed Media 81.48 - 122.22 1/sq m-hr
Suspended solids are commonly removed from wastewater streams by
filtering through a deep 0.3 to 0.9 m (1 to 3 feet) granular
filter bed. The porous bed formed by the granular media can be
designed to remove practically all suspended particles. Even
colloidal suspensions (roughly 1 to 100 microns) are adsorbed on
the surface of the media grains as they pass in close proximity
in the narrow bed passages.
Properly operated filters following some preliminary treatment to
reduce suspended solids below 200 mg/1 should produce water with
less than 10 mg/1 TSS. For example, multimedia filters produced
the effluent qualities shown in Table VII-8.
Advantages and Limitations. The principal advantages of granular
bed filtration are its comparatively (to other filters) low
initial and operating costs, reduced land requirements over other
250
-------
methods to achieve the same level of solids removal, and
elimination of chemical additions to the discharge stream.
However, the waste stream may require preliminary treatment if
the solids level is high (over TOO mg/1). Operator training must
be somewhat extensive due to the controls and periodic
backwashing involved, and backwash must be stored and dewatered
for economical disposal.
Operational Factors. Reliability: The recent improvements in
filter technology have significantly improved filtration
reliability. Control systems, improved designs, and good
operating procedures have made filtration a highly reliable
method of water treatment.
Maintainability: Deep bed filters may be operated with either
manual or automatic backwash. In either case, they must be peri-
odically inspected for media attrition, partial plugging, and
leakage. Where backwashing is not used, collected solids must be
removed by shoveling, and filter media must be at least partially
replaced.
Solid Waste Aspects: Filter backwash is generally recycled
within the wastewater treatment system, so that the solids ulti-
mately appear in the clarifier sludge stream for subsequent
dewatering. Alternatively, the backwash stream may be dewatered
directly or, if there is no backwash, the collected solids may be
disposed of in a suitable landfill. In either of these situa-
tions there is a solids disposal problem similar to that of
clarifiers.
Demonstration Status. Deep bed filters are in common use in
municipal treatment plants. Their use in polishing industrial
clarifier effluent is increasing, and the technology is proven
and conventional. Granular bed filtration is currently used at
six copper forming plants.
4. Pressure Filtration
Pressure filtration works by pumping the liquid through a filter
material which is impenetrable to the solid phase. The positive
pressure exerted by the feed pumps or other mechanical means pro-
vides the pressure differential which is the principal driving
force.
A typical pressure filtration unit consists of a number of plates
or trays which are held rigidly in a frame to ensure alignment
and which are pressed together between a fixed end and a travel-
ing end. On the surface of each plate is mounted a filter made
of cloth or a synthetic fiber. The feed stream is pumped into
the unit and passes through holes in the trays along the length
251
-------
of the press until the cavities or chambers between the trays are
completely filled. The solids are then entrapped, and a cake
begins to form on the surface of the filter material. The water
passes through the fibers, and the solids are retained.
At the bottom of the trays are drainage ports. The filtrate is
collected and discharged to a common drain. As the filter medium
becomes coated with sludge, the flow of filtrate through the
filter drops sharply, indicating that the capacity of the filter
has been exhausted. The unit must then be cleaned of the sludge.
After the cleaning or replacement of the filter media, the unit
is again ready for operation.
Application and Performance. Pressure filtration may be used in
copper forming for sludge dewatering and also for direct removal
of precipitated and other suspended solids from wastewater.
Because dewatering is such a common operation in treatment sys-
tems, pressure filtration is a technique which can be found in
many industries concerned with removing solids from their waste
stream.
In a typical pressure filter, chemically preconditioned sludge
detained in the unit for one to three hours under pressures vary-
ing from 5 to 13 atmospheres exhibited a final dry solids content
between 25 and 50 percent.
Advantages and Limitations. The pressures which may be applied
to a sludge for removal of water by filter presses that are
currently available range from 5 to 13 atmospheres. As a result,
pressure filtration may reduce the amount of chemical
pretreatment required for sludge dewatering. Sludge retained in
the form of the filter cake has a higher percentage of solids
than that from a centrifuge or vacuum filter. Thus, it can be
easily accommodated by materials handling systems.
As a primary solids removal technique, pressure filtration
requires less space than clarification and is well suited to
streams with high solids loadings. The sludge produced may be
disposed of without further dewatering. The amount of sludge is
increased by the use of filter precoat materials (usually dia-
tomaceous earth). Also, cloth pressure filters often do not
achieve as high a degree of effluent clarification as clarifiers
or granular media filters.
Two disadvantages associated with pressure filtration in the past
have been the short life of the filter cloths and lack of auto-
mation. New synthetic fibers have largely offset the first of
these problems. Also, units with automatic feeding and pressing
cycles are now available.
252
-------
For larger operations, the relatively high space requirements, as
compared to those of a centrifuge, could be prohibitive in some
situations.
Operational Factors. Reliability: With proper pretreatment,
design, and control, pressure filtration is a highly dependable
system.
Maintainability: Maintenance consists of periodic cleaning or
replacement of the filter media, drainage grids, drainage piping,
filter pans, and other parts of the system. If the removal of
the sludge cake is not automated, additional time is required for
this operation.
Solid Waste Aspects: Because it is generally drier than other
types of sludges, the filter sludge cake can be handled with
relative ease. The accumulated sludge may be disposed by any of
the accepted procedures depending on its chemical composition.
The levels of toxic metals present in sludge from treating copper
forming wastewater necessitate proper disposal.
Demonstration Status. Pressure filtration is a commonly used
technology in many commercial applications. No copper forming
plants use pressure filtration.
5. Settling
Settling is a process which removes solid particles from a liquid
matrix by gravitational force. This is done by reducing the
velocity of the feed stream in a large volume tank or lagoon so
that gravitational settling can occur. Figure VI1-7 shows two
typical settling devices.
Settling is often preceded by chemical precipitation which
converts dissolved pollutants to solid form and by coagulation
which enhances settling by coagulating suspended precipitates
into larger, faster settling particles.
If no chemical pretreatment is used, the wastewater is fed into a
tank or lagoon where it loses velocity and the suspended solids
are allowed to settle out. Long retention times are generally
required. Accumulated sludge can be collected either periodi-
cally or continuously and either manually or mechanically.
Simple settling, however, may require excessively large catch-
ments, and long retention times (days as compared with hours) to
achieve high removal efficiencies. Because of this, addition of
settling aids such as alum or polymeric flocculants is often
economically attractive.
253
-------
In practice, chemical precipitation often precedes settling, and
inorganic coagulants or polyelectrolytic flocculants are usually
added as well. Common coagulants include sodium sulfate, sodium
aluminate, ferrous or ferric sulfate, and ferric chloride.
Organic polyelectrolytes vary in structure, but all usually form
larger floe particles than coagulants used alone.
Following this pretreatment, the wastewater can be fed into a
holding tank or lagoon for settling, but is more often piped into
a clarifier for the same purpose. A clarifier reduces space
requirements, reduces retention time, and increases solids
removal efficiency. Conventional clarifiers generally consist of
a circular or rectangular tank with a mechanical sludge collect-
ing device or with a sloping funnel-shaped bottom designed for
sludge collection. In advanced settling devices, inclined
plates, slanted tubes, or a lamellar network may be included
within the clarifier tank in order to increase the effective
settling area, increasing capacity. A fraction of the sludge
stream is often recirculated to the inlet, promoting formation of
a denser sludge.
Application and Performance. Settling and clarification are used
in the copper forming category to remove precipitated metals.
Settling can be used to remove most suspended solids in a
particular waste stream; thus it is used extensively by many
different industrial waste treatment facilities. Because most
metal ion pollutants are readily converted to solid metal
hydroxide precipitates, settling is of particular use in those
industries associated with metal production, metal finishing,
metal working, and any other industry with high concentrations of
metal ions in their wastewaters. In addition to toxic metals,
suitably precipitated materials effectively removed by settling
include aluminum, iron, manganese, cobalt, antimony, beryllium,
molybdenum, fluoride, phosphate, and many others.
A properly operated settling system can efficiently remove sus-
pended solids, precipitated metal hydroxides, and other impuri-
ties from wastewater. The performance of the process depends on
a variety of factors, including the density and particle size of
the solids, the effective charge on the suspended particles, and
the types of chemicals used in pretreatment. The site of floccu-
lant or coagulant addition also may significantly influence the
effectiveness of clarification. If the flocculant is subjected
to too much mixing before entering the clarifier, the complexes
may be sheared and the settling effectiveness diminished. At the
same time, the flocculant must have sufficient mixing and reac-
tion time in order for effective set-up and settling to occur.
Plant personnel have observed that the line or trough leading
into the clarifier is often the most efficient site for floccu-
lant addition. The performance of simple settling is a function
254
-------
of the retention time, particle size and density, and the surface
area of the basin.
The data displayed in Table VI1-9 indicate suspended solids
removal efficiencies in settling systems.
The mean effluent TSS concentration obtained by the plants shown
in Table VII-9 is 10.1 mg/1. Influent concentrations averaged
838 mg/1. The maximum effluent TSS value reported is 23 mg/1.
These plants all use alkaline pH adjustment to precipitate metal
hydroxides, and most add a coagulant or flocculant prior to
settling.
Advantages and Limitations. The . major advantage of simple
settling is its simplicity as demonstrated by the gravitational
settling of solid particulate waste in a holding tank or lagoon.
The major problem with simple settling is the long retention time
necessary to achieve an acceptable effluent, especially if the
specific gravity of the suspended matter is close to that of
water. Some materials cannot be effectively removed by simple
settling alone.
Settling performed in a clarifier is effective in removing slow-
settling suspended matter in a shorter time and in less space
than a simple settling system. Also, effluent quality is often
better from a clarifier. The cost of installing and maintaining
a clarifier, however, is substantially greater than the cost
associated with simple settling.
Inclined plate, slant tube, and lamellar settlers have even
higher removal efficiencies than conventional clarifiers, and
greater capacities per unit area are possible. Installed costs
for these advanced clarification systems are claimed to be one
half the cost of conventional systems of similar capacity.
Operational Factors. Reliability: Settling can be a highly
reliable technology for removing suspended solids. Sufficient
retention time and regular sludge removal are important factors
affecting the reliability of all settling systems. Proper con-
trol of pH adjustment, chemical precipitation, and coagulant or
flocculant addition are additional factors affecting settling
efficiencies in systems (frequently clarifiers) where these
methods are used.
Those advanced settlers using slanted tubes, inclined plates, or
a lamellar network may require prescreening of the waste in order
to eliminate any fibrous materials which could potentially clog
the system. Some installations are especially vulnerable to
shock loadings, as by storm water runoff, but proper system
design will prevent this.
255
-------
Maintainability: When clarifiers or other advanced settling
devices are used, the associated system utilized for chemical
pretreatment and sludge dragout must be maintained on a regular
basis. Routine maintenance of mechanical parts is also neces-
sary. Lagoons require little maintenance other than periodic
sludge removal.
Demonstration Status. Settling represents the typical method of
solids removal and is employed extensively in industrial waste
treatment. The advanced clarifiers are just beginning to appear
in significant numbers in commercial applications. Thirty-six
copper forming plants use sedimentation or clarification.
6. Skimming
Pollutants with a specific gravity less than water will often
float unassisted to the surface of the wastewater. Skimming
removes these floating wastes. Skimming normally takes place in
a tank designed to allow the floating material to rise and remain
on the surface, while the liquid flows to an outlet located below
the floating layer. Skimming devices are therefore suited to the
removal of non-emulsified oils from raw waste streams. Common
skimming mechanisms include the rotating drum type, which picks
up oil from the surface of the water as it rotates. A doctor
blade scrapes oil from the drum and collects it in a trough for
disposal or reuse. The water portion is allowed to flow under
the rotating drum. Occasionally, an underflow baffle is
installed after the drum; this has the advantage of retaining any
floating oil which escapes the drum skimmer. The belt type
skimmer is pulled vertically through the water, collecting oil
which is scraped off from the surface and collected in a drum.
Gravity separators (Figure VII-8), such as the API type, utilize
overflow and underflow baffles to skim a floating oil layer from
the surface of the wastewater. An overflow-underflow baffle
allows a small amount of wastewater (the oil portion) to flow
over into a trough for disposition or reuse while the majority of
the water flows underneath the baffle. This is followed by an
overflow baffle, which is set at a height relative to the first
baffle such that only the oil bearing portion will flow over the
first baffle during normal plant operation. A diffusion device,
such as a vertical slot baffle, aids in creating a uniform flow
through the system and increasing oil removal efficiency.
Application and Performance. Skimming is applicable to any waste
stream containing pollutants which float to the surface. It is
commonly used to remove free oil, grease, and soaps. Skimming is
often used in conjunction with air flotation or clarification in
order to increase its effectiveness.
256
-------
The removal efficiency of a skimmer is partly a function of the
retention time of the water in the tank. Larger, more buoyant
particles require less retention time than smaller particles.
Thus, the efficiency also depends on the composition of the waste
stream. The retention time required to allow phase separation
and subsequent skimming varies from 1 to 15 minutes, depending on
the wastewater characteristics.
API or other gravity-type separators tend to be more suitable for
use where the amount of surface oil flowing through the system is
continuous and substantial. Drum and belt type skimmers are
applicable to waste streams which evidence smaller amounts of
floating oil and where surges of floating oil are not a problem.
Using an API separator system in conjunction with a drum type
skimmer would be a very effective method of removing floating
contaminants from non-emulsified oily waste streams. Sampling
data shown in Table VII-10 illustrate the capabilities of the
technology with both extremely high and moderate oil influent
levels.
This data is intended to be illustrative of the very high level
of oil and grease removals attainable in a simple two stage oil
removal system. Based on the performance of installations in a
variety of manufacturing plants and permit requirements that are
constantly achieved, it is determined that effluent oil levels
may be reliably reduced below 10 mg/1 with moderate influent
concentrations. Very high concentrations of oil such as the 22
percent;shown in Table VII-10 may require two step treatment to
achieve this level.
Skimming which removes oil may also be used to remove base levels
of organics. Plant sampling data show that many organic com-:
pounds tend to be removed in standard wastewater treatment equip-
ment. Oil separation not only removes oil but also organics that
are more soluble in oil than in water. Clarification removes
organic solids directly and probably removes dissolved organics
by adsorption on inorganic solids.
The source of these organic pollutants is not always known with
certainty, although in metal forming operations they seem to
derive mainly from various process, lubricants. They are also
sometimes present in the plant water supply, as additives to
proprietary formulations of cleaners, or due to leaching from
plastic liners and other materials.
High molecular weight organics in particular are much more solu-
ble in organic solvents than in water. Thus they are much more
concentrated in the oil phase that is skimmed than in the waste-
water. The ratio of solubilities of a compound in oil and water
phases is called the partition coefficient. The logarithm of the
257
-------
partition coefficients for 15 polynuclear aromatic hydrocarbon
(PAH) compounds in octanol and water are:
Log Octanol/Water
PAH Priority Pollutant Partition Coefficient
1. Acenaphthene 4.33
30. Fluoranthene 5.33
72. Benzota)anthracene 5.61
73. Benzo(a)pyrene 6.04
74. 3,4-Benzofluoranthene 6.57
75. Benzo(k)fluoranthene 6.84
76. Chrysene 5.61
77. Acenaphthylene 4.07
78. Anthracene 4.45
79. Benzo(ghi)perylene 7.23
80. Fluorene 4.18
81. Phenanthrene 4.46
82. Dibenzo(a,h)anthracene 5.97
83. Indenod,2,3,cd)pyrene 7.66
84. Pyrene 5.32
Figure VII-9 shows the relationship between the concentrations of
total toxic organics and oil and grease in wastewater samples
from copper forming plants. It can be seen that if a daily
maximum oil and grease concentration of 20 mg/1 is achieved, the
concentration of total toxic organics is expected to be below 0.5
mg/1. This conclusion is also supported by data from copper
forming plants which practice oil skimming on wastewaters which
contain toxic organics as well as oil and grease. Data from
three days of sampling at two copper forming plants which prac-
tice oil skimming and achieve effluent oil and grease concentra-
tions of 20 mg/1 or less are presented in Table VII-11. It can
be seen that the concentration of total toxic organics in these
effluent samples never exceeds 0.31 mg/1.
Advantages and Limitations. Skimming as a pretreatment is
effective in removing naturally floating waste material. It also
improves the performance of subsequent downstream treatments.
Many pollutants, particularly dispersed or emulsified oil, will
not float "naturally" but require additional treatments. There-
fore, skimming alone may not remove all the pollutants capable of
being removed by air flotation or other more sophisticated tech-
nologies.
Operational Factors. Reliability: Because of its simplicity,
skimming is a very reliable technique.
Maintainability: The skimming mechanism requires periodic
lubrication, adjustment, and replacement of worn parts.
258
-------
Solid Waste Aspects: The collected layer of debris must be
disposed of by contractor removal, landfill, or incineration.
Because relatively large quantities of water are present in the
collected wastes, incineration is not always a viable disposal
method. c
Demonstration Status. Skimming is a common operation utilized
extensively by industrial waste treatment systems. It is
presently used at 10 copper forming plants.
7. Chemical Emulsion Breaking
Chemical treatment is often used to break stable oil-in-water (0-
W) emulsions. An 0-W emulsion consists of oil dispersed in
water, stabilized by electrical charges and emulsifying agents.
A stable emulsion will not separate or break down without some
form of treatment.
Once an emulsion is broken, the difference in specific gravities
allows the oil to float to the surface of the water. Solids usu-
ally form a layer between the oil and water, since some oil is
retained in the solids. The longer the retention time, the more
complete and distinct the separation between the oil. solids, and
water will be. Often other methods of gravity differential
separation, such as air flotation or rotational separation (e g
centrifugation), are used to enhance and speed separation A
schematic flow diagram of one type of application is shown in
Figure VII-10.
The major equipment required for chemical emulsion breaking
includes: reaction chambers with agitators, chemical storage
tanks, chemical feed systems, pumps, and piping.
Emulsifiers may be used in the plant to aid in stabilizing or
forming emulsions. Emulsifiers are surface-active agents which
alter the characteristics of the oil and water interface. These
sufactants have rather long polar molecules. One end of the
molecule is particularly soluble in water (e.g., carboxyl, sul-
fate, hydroxyl, or sulfonate groups) and the other end is readily
soluble in oils (an organic group which varies greatly with the
different surfactant type). Thus, the surfactant emulsifies or
suspends the organic material (oil) in water. Emulsifiers also
lower the surface tension of the 0-W emulsion as a result of
solvation and ionic complexing. These emulsions must be
destabilized in the treatment system.
Application and Performance. Emulsion breaking is applicable to
waste streams containing emulsified oils or lubricants such as
rolling and drawing emulsions.
259
-------
Treatment of spent 0-W emulsions involves the use of chemicals to
break the emulsion followed by gravity differential separation.
Factors to be considered for breaking emulsions are type of chem-
icals, dosage and sequence of addition, pH, mechanical shear and
agitation, heat, and retention time.
Chemicals, e.g., polymers, alum, ferric chloride, and organic
emulsion breakers, break emulsions by neutralizing repulsive
charges between particles, precipitating or salting out emul-
sifying agents, or altering the interfacial film between the oil
and water so it is readily broken. Reactive cations, e.g.,
H(+l), AK+3), Fe(+3), and cationic polymers, are particularly
effective in breaking dilute 0-W emulsions. Once the charges
have been neutralized or the interfacial film broken, the small
o%l droplets and suspended solids will be adsorbed on the surface
of the floe that is formed, or break out and float to the top.
Various types of emulsion-breaking chemicals are used for the
various types of oils.
If more than one chemical is required, the sequence of addition
can make quite a difference in both breaking efficiency and
chemical dosages.
pH plays an important role in emulsion breaking, especially if
cationic inorganic chemicals, such as alum, are used as coagu-
lants. A depressed pH in the range of 2 to 4 keeps the aluminum
ion in its most positive state where it can function most effec-
tively for charge neutralization. After some of the oil is
broken free and skimmed, raising the pH into the 6 to 8 range
with lime or caustic will cause the aluminum to hydrolyze and
precipitate as aluminum hydroxide. This floe entraps or adsorbs
destabilized oil droplets which can then be separated from the
water phase. Cationic polymers can break emulsions over a wider
pH range and thus avoid acid corrosion and the additional sludge
generated from neutralization; however, an inorganic flocculant
is usually required to supplement the polymer emulsion breaker's
adsorptive properties.
Mixing is important in breaking 0-W emulsions. Proper chemical
feed and dispersion is required for effective results. Mixing
also causes collisions which help break the emulsion, and sub-
sequently helps to agglomerate droplets.
p
In all emulsions, the mix of two immiscible liquids has a spe-
cific gravity very close to that of water. Heating lowers the
viscosity and increases the apparent specific gravity differen-
tial between oil and water. Heating also increases the frequency
of droplet collisions, which helps to rupture the interfacial
film.
260
-------
Oil and grease and suspended solids performance data are shown in
Table VII-12. Data were obtained from sampling at operating
plants and a review of the current literature. This type of
treatment is proven to be reliable and is considered the current
state-of-the-art for copper forming emulsified oily wastewaters.
Advantages and Limitations. Advantages gained from the use of
chemicals for breaking 0-W emulsions are the high removal
efficiency potential and the possibility of reclaiming the oily
waste. Disadvantages are corrosion problems associated with
acid-alum systems, skilled operator requirements for batch treat-
ment, chemical sludges produced, and poor cost-effectiveness for
low oil concentrations.
Operational Factors. Reliability: Chemical emulsion breaking is
a very reliable process. The main control parameters, pH and
temperature, are fairly easy to control.
Maintainability: Maintenance is required on pumps, motors, and
valves, as well as periodic cleaning of the treatment tank to
remove any accumulated solids. Energy use is limited to mixers
and pumps.
Solid Waste Aspects: The surface oil and oily sludge produced
are usually hauled away by a licensed contractor. If the recov-
ered oil has a sufficiently low percentage of water, it may be
burned for its fuel value or processed and reused.
Demonstration Status. Four plants in the copper forming industry
currently use chemical emulsion breaking.
8« Thermal Emulsion Breaking
Dispersed oil droplets in a spent emulsion can be destabilized by
the application of heat to the waste. One type of technology
commonly used in the metals and mechanical products industries is
the evaporation-decantation-condensation process, also called
thermal emulsion breaking (TEB), which separates the emulsion
waste into distilled water, oils and other floating materials,
and sludge. Raw waste is fed to a main reaction chamber. Warm
air is passed over a large revolving drum which is partially sub-
merged in the waste. Some water evaporates from the surface,of
the drum and is carried upward through a filter and a condensing
unit. The condensed water is discharged or reused as process
makeup, while the air is reheated and returned to the evaporation
stage. As the water evaporates in the main chamber, oil concen-
tration increases. This enhances agglomeration and gravity sepa-
ration of oils. The separated oils and other floating materials
flow over a weir into a decanting chamber. A rotating drum
skimmer picks up oil from the surface of the decanting chamber
261
-------
and discharges it for possible reprocessing or contractor
removal. Meanwhile, oily water is being drawn from the bottom of
the decanting chamber, reheated, and sent back into the main con-
veyor ized chamber. Solids which settle out in the main chamber
are removed by a conveyor belt. This conveyor belt, called a
flight scraper, moves slowly so as not to interfere with the
settling of suspended solids.
Application and Performance. Thermal emulsion breaking
technology can be applied to the treatment of spent emulsions in
the copper forming category.
The performance of a thermal emulsion breaker is dependent
primarily on the characteristics of the raw waste and proper
maintenance and functioning of the process components. Some
emulsions may contain volatile compounds which could escape with
the distilled water. In systems where the water is recycled back
to process, however, this problem is essentially elminated.
Experience in at least two copper forming plants has shown that
trace organics or other contaminants found in the condensed water
will not adversely affect the lubricants when this water is used
for process emulsions. In one copper forming plant, typical oil
and grease level in the condensed water was 1 mg/1.
Advantages and Limitations. Advantages of the thermal emulsion
breaking processinclude high percentages of oil removal (at
least 99 percent in most cases), the separation of floating oil
from settleable sludge solids, and the production of distilled
water which is available for process reuse. In addition, no
chemicals are required and the operation is automated, factors
which reduce operating costs. Disadvantages of the process are
the energy requirement for water evaporation and, if
intermittently operated, the necessary installation of a large
storage tank.
Operational Factors. Reliability: Thermal emulsion breaking is
a very reliable process for the treatment of emulsified oil
wastes.
Maintainability: The thermal emulsion breaking process requires
minimal routine maintenance of the process components, and peri-
odic disposal of the sludge and oil.
Solid Waste Aspects: The thermal emulsion breaking process
generates sludge which must be properly disposed of.
Demonstration Status. Thermal emulsion breaking is used in
metals and mechanical products industries. It is a proven method
of effectively treating emulsified wastes. Six copper forming
plants currently use thermal emulsion breaking.
262
-------
MAJOR TECHNOLOGY EFFECTIVENESS
The performance of individual treatment technologies was pre-
sented above. Performance of operating systems is discussed
here. Two different systems are considerred: L&S (hydroxide
precipitation and sedimentation or lime and settle) and LS&F
(hydroxide precipitation, sedimentation, and filtration or lime,
settle, and filter). Subsequently, an analysis of effectiveness
of such systems is made to develop one-day maximum and ten-day
and thirty-day average concentration levels to be used in regu-
lating pollutants. Evaluation of the L&S and the LS&F systems is
carried out on the assumption that chemical reduction of chro-
mium, cyanide precipitation, oil skimming, and emulsion breaking
are installed and operating properly where appropriate.
L&S Performance - Combined Metals Data Base (CMDB)
A data base known as the "combined metals data base" (CMDB) was
used to determine treatment effectiveness of lime and settle
treatment for certain pollutants. The CMDB was developed over
several years and has been used in a number of regulations.
Before proposal, chemical analysis data were collected of raw
waste (treatment influent) and treated waste (treatment effluent)
from 55 plants (126 data days) sampled by EPA (or its contractor)
using EPA sampling and chemical analysis protocols. These data
were the initial data base for determining the effectiveness of
L&S technology in treating nine pollutants. Each of these plants
belongs to at least one of the following industry categories:
copper forming, battery manufacturing, coil coating, aluminum
forming, electroplating and porcelain enameling. All of the
plants employ pH adjustment and hydroxide precipitation using
lime or caustic, followed by Stokes law settling (tank, lagoon or
clarifier) for solids removal. Most also add a coagulant or
flocculant prior to solids removal.
An analysis of this data was presented in the development docu-
ments for the proposed regulations for coil coating and porcelain
enameling (January 1981). Prior to analyzing the data, some
values were deleted from the data base. These deletions were
made to ensure that the data reflect properly operated treatment
systems. The following criteria were used in making these
deletions:
Plants where malfunctioning processes or treatment
systems at the time of sampling were identified.
Data days where pH was less than 7.0 for extended
periods of time or TSS was greater than 50 mg/1 (these
are prima facie indications of poor operation).
263
-------
In response to the coil coating and copper forming proposals,
some commenters claimed that it was inappropriate to use data
from some categories for regulation of other categories. In
response to these comments, the Agency reanalyzed the data. .An
analysis of variance was applied to the data for the 126 days of
sampling to test the hypothesis of homogeneous plant mean raw and
treated effluent levels across categories by pollutant. This
analysis is described in the report, "A Statistical Analysis of
the Combined Metals Industries Effluent Data" which is in the
administrative record supporting this rulemaking. The main
conclusion drawn from the analysis of variance is that, with the
exception of electroplating, the categories included in the data
base are generally homogeneous with regard to mean pollutant
concentrations in both raw and treated effluent. That is, when
data from electroplating facilities are included in the analysis,
the hypothesis of homogeneity across categories is rejected.
When the electroplating data are removed from the analysis the
conclusion changes substantially and the hypothesis of homogene-
ity across categories is not rejected. On the basis of this
analysis, the electroplating data were removed from the data base
used to determine limitations for the final coil coating and
porcelain enameling regulations and proposed regulations for
copper forming, aluminum forming and battery manufacturing.
i
The statistical analysis provides support for the technical engi-
neering judgment that electroplating wastewaters are sufficiently
different from the wastewaters of the other industrial categories
in the data base to warrant the removal of electroplating data
from the data base.
For the purpose of determining treatment effectiveness,
additional data were deleted from the data base. These deletions
were made, almost exclusively, in cases where effluent data
points were associated with low influent values. This was done
in two steps. First, effluent values measured on the same day as
influent values that were less than or equal to 0.1 mg/1 were
deleted. Second, the remaining data were screened for cases in
which all influent values at a plant were low although slightly
above the 0.1 mg/1 value. These data were deleted not as
individual data points but as plant clusters of data that were
consistently low and thus not relevant to assessing treatment. A
few data points were also deleted where malfunctions not
previously identified were recognized.
After all deletions, 148 data points from 19 plants remained.
These data were used to establish the concentration bases of the
limitations and standards for the copper forming proposal.
Following the proposal of the copper forming regulation, the CMDB
was reviewed. Comments pointed out a few errors in the data and
264
-------
the Agency's review identified a few transcription errors and
some data points that were appropriate for inclusion in the data
that had not been used previously because of errors in data
record identification numbers. Documents in the record of this
rulemaking identify all the changes, the reasons for the changes,
and the effects of these changes on the data base.
The revised data base was re-examined for homogeneity. The
earlier conclusions were unchanged. The categories show good
overall homogeneity with respect to concentrations of the nine
pollutants in both raw and treated wastewaters with the exception
of electroplating.
The same procedures used in developing proposed limitations from
the combined metals data base were then used on the revised data
base. That is, certain effluent data associated with low influ-
ent values were deleted, and then the remaining data were fit to
a lognormal distribution to determine limitations values. The
deletion of data was done again in two steps. First, effluent
values measured on the same day as influent values that were less
than or equal to 0.1 mg/1 were deleted. Second, the remaining
data were screened for cases in which all influent values at a
plant were low although slightly above the 0.1 mg/1 value. These
data were deleted not as individual data points but as plant
clusters of data that were consistently low and thus not relevant
to assessing treatment.
The revised combined metals data base used for this final regula-
tion consists of 162 data points from 18 plants in the same
industrial categories used at proposal. The changes that were
made since proposal resulted in slight upward revisions of the
concentration bases for the limitations and standards for zinc
and nickel. The limitations for iron decrease slightly. The
other limitations were unchanged. A comparison of Table VI1-20
in the final development document with Table VII-21 in the pro-
posal development document will show the exact magnitude of the
changes.
The Agency is confident that the concentrations calculated from
the combined metals data base accurately reflect the ability of
lime and settle systems in copper forming plants to reduce the
concentrations of the toxic metals in their raw waste streams.
The Agency confirmed this judgment by comparing available dis-
charge monitoring report (DMR) data from 15 discharge points in
copper forming plants. This comparison led to the conclusion
that the concentrations calculated from the combined metals data
base were being achieved by most discharge points over long peri-
ods of time. The analysis of the DMR data is documented in the
record of this rulemaking.
265
-------
One-Day Effluent Values
The same procedures used to determine the concentration basis of
the limitations for lime and settle treatment from the CMDB at
proposal were used on the revised CMDB for the final limitations.
The basic assumption underlying the determination of treatment
effectiveness is that the data for a particular pollutant are
lognormally distributed by plant. The lognormal has been found
to provide a satisfactory fit to plant effluent data in a number
of effluent guidelines categories and there was no evidence that
the lognormal was not suitable in the case of the combined metals
data. Thus, the measurements of each pollutant from a particular
plant, denoted by X, were assumed follow a lognormal distribution
with a log mean » and log variance tf2. The mean, variance, and
99th percentile of X are then:
mean of X = E (X) = exp U + tf2/2)
variance of X = V(X) = exp (2? + *2) [exp U2) - 1]
99th percentile = X.99 = exp (* + 2.33 *)
where exp is e, the base of the natural logarithm. The term
lognormal is used because the logarithm of X has a normal
distribution with mean n and variance *2. Using the basic
assumption of lognormality, the actual treatment effectiveness
was determined using a lognormal distribution that, in a sense,
approximates the distribution of an average of the plants in the
data base, i.e., an "average plant" distribution. The notion of
an "average plant" distribution is not a strict statistical con-
cept but is used here to determine limits that would represent
the performance capability of an average of the plants in the
data base.
This "average plant" distribution for a particular pollutant was
developed as follows: the log mean was determined by taking the
average of all the observations for the pollutant across plants.
The log variance was determined by the pooled within plant
variance. This is the weighted average of the plant variances.
Thus, the log mean represents the average of all the data for the
pollutant and the log variance represents the average of the
plant log variances or average plant variability for the
pollutant.
The one-day effluent values were determined as follows:
Let Xij = the jth observation on a particular pollutant at
plant i where
i = 1, . . ., I
j - 1, . . ., Ji
266
-------
I • total number of plants
Ji = number of observations at plant i
Then Yij = In X ij
where In means the natural logarithm.
Then y = log mean over all plants
I Ji
Yij/n
where n = total number of observations
I
Ji
i = l
and V(y) = pooled log variance
I
(Ji -1 )Si*
i -n
where Si2 « log variance at plant i.
Ji
(yij - yi
? = ]
yi= log mean at plant i.
Thus, y and V(y) are the log mean and log variance, respectively,
of the lognormal distribution used to determine the treatment
effectiveness. The estimated mean and 99th percentile of this
distribution form the basis for the long term average and daily
maximum effluent limitations, respectively. The estimates are
mean = E(X) = exp(y) n(0.5V(y»
99th percentile = X.99 = exp [y + 2.33 V (y) ]
where (.) is a Bessel function and exp is e, the base of the
natural logarithms (see Aitchison, J. and J. A. C. Brown, The
Loqnormal Distribution. Cambridge University Press, 1963). ~7n"
267
-------
cases where zeros were present in the data, a generalized form of
the lognormal, known as the delta distribution was used (see
Aitchison and Brown, op. cit.. Chapter 9).
For certain pollutants, this approach was modified slightly to
ensure that well operated lime and settle plants in 'all CMDB
categories could meet the concentrations calculated from this
data. For instance, after excluding the electroplating data and
other data that did not reflect pollutant removal or proper
treatment, the effluent copper data from the copper forming
plants were statistically significantly greater than the copper
data from the other plants. This indicated that copper forming
plants might have difficulty achieving an effluent concentration
value calculated from copper data from all the CMDB categories.
Thus, copper effluent values shown in Table VII-13 are based only
on the copper effluent data from the copper forming plants. That
is, the log mean for copper is the mean of the logs of all copper
values from the copper forming plants only and the log variance
is the pooled log variance of the copper forming plant data only.
In the case of cadmium, after excluding the electroplating data
and data that did not reflect removal or proper treatment, there
were insufficient data to estimate the log variance for cadmium.
The variance used to determine the values shown in Table VII-13
for cadmium was estimated by pooling the within plant variances
for all the other metals. Thus, the cadmium variability is the
average of the plant variability averaged over all the other
metals. The log mean for cadmium is the mean of the logs of the
cadmium observations only. A complete discussion of the data and
calculations for all the metals is contained in the administra-
tive record for this rulemaking.
Monthly Average Effluent Values
Average effluent values that form the basis for the monthly
limitations were developed in a manner consistent with the method
used to develop one-day treatment effectiveness in that the log-
normal distribution used for the one-day effluent values was also
used as the basis for the average values. That is, we assume a
number of consecutive measurements are drawn from the distribu-
tion of daily measurements. The average of ten consecutive daily
measurements (but not necessarily taken on ten consecutive days)
was used as the basis of the monthly average limitations. The
approach used for the 10 measurement monthly limitations values
was employed previously in regulations for other categories and
was proposed for the copper forming category. That is, the
distribution of the average of 10 samples from a lognormal was
approximated by another lognormal distribution. Although the
approximation is not precise theoretically, there is empirical
evidence based on effluent data from a number of categories that
the lognormal is an adequate approximation for the distribution
268
-------
i~~ Tn fhe> course of previous work the
assumed .
Ten-Sample Average:
consecuU^'mealurlments^-The folloiJnfl relationships then hold
assuming the daily measurements are independent:
mean of X10 = E = E(x)
variance of X10 = V(X10) = Vtx) * 1°,
^./vi ^A ^Jl•sc^ are the mean and variance of X, respectively,
£ l^i''
The mean and variance of X10 are then
E(X10) « exp(..,o + 0.5»2,0)
V(X10) = expUno + «2io
Now, ,10 and ^10 can be derived in terms of , and <* as
„,„ . M + «z/2 + 0.51n[l + (exp(«2 -
Therefore, ,10 and .-}9 can be estimated -g^th. above
relationships and the estimates of „ and . obtanea n
underlying lognormal d«tribution. Tne w app?oximate 99th
^'sample average given by
X10 (-99) = exp (MIO + 2-33 'to)
where Mo and ,10 are the estimates of ,10 and ,10, respectively.
269
-------
30 Sample Average:
H» to r
' °"
•
.
'
-sar .»
30 Sample Average Calculation
distributed.' The meln anS var?^ce of tj^?™**1* n°rma11*
mean of X30 = E(X30) = E(X)
variance of X30 = V(x30) = v(X) -r 30.
average given by
X,0<.99> = E(X) + 2.33 V(X) 30
where E(X) * exp(y) n(0.5V(y))
!stimate of
of the 30 sample
270
-------
and V{X) = exp(2y)[ n(2V(y)> = n n-2 V(y) ].
The formulas for E(X) and V(X) are estimates of E
-------
raw wastewater. These data have been selected from processes
that generate dissolved metals in the wastewater and which are
generally free from complexing agents. The pollutant matrix was
evaluated by comparing the concentrations of pollutants found in
the raw wastewaters with the range of pollutants in the raw
wastewaters of the combined metals data set. These data are
displayed in Tables VII-15 and VII-16 and indicate that there is
sufficient similarity in the raw wastes to logically assume
transferability of the treated pollutant concentrations to the
combined metals data base. The available data on these added
pollutants do riot allow homogeneity analysis as was performed on
the combined metals data base. The data source for each added
pollutant is discussed separately.
Antimony (Sb) - The achievable performance for antimony is based
on data from a battery and secondary lead plant. Both EPA
sampling data and recent permit data (1978 - 1982) confirm the
achievability of 0.70 mg/1 in the battery manufacturing
wastewater matrix included in the combined data set.
Arsenic (As) - The achievable performance of 0.51 mg/1 for
arsenic is based on permit data from two nonferrous metals
manufacturing plants. The untreated wastewater matrix shown in
Table VII-16 is comparable with the combined data set matrix.
Beryllium (Be) - The treatability of beryllium is transferred
from the nonferrous metals manufacturing industry. The 0.3 per-
formance is achieved at a beryllium plant with the comparable
untreated wastewater matrix shown in Table VII-16.
Mercury (Hq) - The 0.06 mg/1 treatability of mercury is based on
data from four battery plants. The untreated wastewater matrix
at these plants was considered in the combined metals data set.
Selenium (Se) - The 0.30 mg/1 treatability of selenium is based
on recent permit data from one of the nonferrous metals
manufacturing plants also used for antimony performance. The
untreated wastewater matrix for this plant is shown in Table VII-
16.
Silver (Aq) - The treatability of silver is based on a 0.1 mg/1
treatability estimate from the inorganic chemicals industry.
Additional data supporting a treatability as stringent or more
stringent than 0.1 mg/1 is also available from seven nonferrous
metals manufacturing plants. The untreated wastewater matrix for
these plants is comparable and summarized in Table VII-16.
Thallium (Th) - The 0.50 mg/1 treatability for thallium is
transferred from the inorganic chemicals industry. Although no
untreated wastewater data are available to verify comparability
272
-------
with the combined metals data set plants, no other sources of
data for thallium treatability could be identified.
Aluminum (Al) - The 2.24 mg/1 treatability of aluminum is based
on the mean performance of three aluminum forming plants and one
coil coating plant. All of these plants are from categories
considered in the combined metals data set, assuring untreated
wastewater matrix comparability.
Cobalt (Co) - The 0.05 mg/1 treatability is based on nearly
complete removal of cobalt at a porcelain enameling plant with a
mean untreated wastewater cobalt concentration of 4.31 mg/1. In
this case, the analytical detection using aspiration techniques
for this pollutant is used as the basis of the treatability.
Porcelain enameling was considered in the combined metals data
base, assuring untreated wastewater matrix comparability.
Fluoride (F) - The 14.5 mg/1 treatability of fluoride is based on
the mean performance of an electronics and electrical component
manufacturing plant. The untreated wastewater matrix for this
plant shown in Table VII-16 is comparable to the combined metals
data set.
LS&F Performance
Tables VII-17 and VII-18 show long-term data from two plants
which have well operated precipitation-settling treatment
followed by filtration. The wastewaters from both plants contain
pollutants from metals processing and finishing operations
(multi-category). Both plants reduce hexavalent chromium before
neutralizing and precipitating metals with lime. A clarifier is
used to remove much of the solids load and a filter is used to
"polish" or complete removal of suspended solids. Plant A uses
pressure filtration, while Plant B uses a rapid sand filter.
Raw waste data was collected only occasionally at each facility
and the raw waste data is presented as an indication of the
nature of the wastewater treated. Data from Plant A was received
as a statistical summary and is presented as received. Raw lab-
oratory data was collected at Plant B and reviewed for spurious
points and discrepancies. The method of treating the data base
is discussed below under lime, settle, and filter treatment
effectiveness.
Table VII-19 shows long-term data for zinc and cadmium removal at
Plant C, a primary zinc smelter, which operates a LS&F system.
This data represents about four months (103 data days) taken
immediately before the smelter was closed. It has been arranged
similarily to Plants A and B for comparison and use.
273
-------
These data are presented to demonstrate the performance of
precipitation-settling-filtration (LS&F) technology under actual
operating conditions and over a long period of time.
It should be noted that the iron content of the raw waste of
plants A and B is high while that for Plant C is low. This
results, for plants A and B, in co-precipitation of toxic metals
with iron. Precipitation using high-calcium lime for pH control
yields the results shown in Table VII-19. Plant operating per-
sonnel indicate that this chemical treatment combination (some-
times with polymer assisted coagulation) generally produces
better and more consistent metals removal than other combinations
of sacrificial metal ions and alkalis.
The LS&F performance data presented here are based on systems
that provide polishing filtration after effective L&S treatment.
As previously shown, L&S treatment is equally applicable to
wastewaters from the five categories because of the homogeneity
of its raw and treated wastewaters, and other factors. Because
of the similarity of the wastewaters after L&S treatment, the
Agency believes these wastewaters are equally amenable to
treatment using polishing filters added to the L&S treatment
system. The Agency has made the determination that wastewaters
from porcelain enameling and copper forming are similar in all
material aspects based on engineering considerations and the
analysis of the combined data set for L&S treatment. Similarly,
the Agency determined that the wastewater from one nonferrous
metals plant that uses lime, settle, and filter is similar in all
material respects to the raw wastewaters in the combined metals
data base. Therefore, the performance of lime and settle, and
filter technology from these plants is directly applicable to the
copper forming category as well as the aluminum forming, battery
manufacturing, coil coating, metal molding, and casting
categories.
Analysis of Treatment System Effectiveness
Data are presented in Table VII-13 showing the mean, one day, 10-
day, and 30-day values for nine pollutants examined in the L&S
metals data base. The mean variability factor for eight pollu-
tants (excluding cadmium because of the small number of data
points) was determined and is used to estimate one day, 10-day,
and 30-day values. (The variability factor is the ratio of the
value of concern to the mean: the average variability factors
are: one day maximum - 4.100; ten-day average - 1.821; and 30-
day average - 1.618.) For values not calculated from the common
data base as previously discussed, the mean value for pollutants
shown in Table VII-14 were multiplied by the variability factors
to derive the value to obtain the one, ten- and 30-day values.
These are tabulated in Table VI1-20.
274
-------
LS&F technology data are presented in Tables VII-17 and VII-18.
These data represent two operating plants {A and B) in which the
technology has been installed and operated for some years. Plant
A data was received as a statistical summary and is presented
without change. Plant B data was received as raw laboratory
analysis data. Discussions with plant personnel indicated that
operating experiments and changes in materials and reagents and
occasional operating errors had occurred during the data collec-
tion period. No specific information was available on those
variables. To sort out high values probably caused by method-
ological factors from random statistical variability, or data
noise, the Plant B data were analyzed. For each of the four
pollutants (chromium, nickel, zinc, and iron), the mean and
standard deviation (sigma) were calculated for the entire data
set. A data day was removed from the complete data set when any
individual pollutant concentration for that day exceeded the sum
of the mean plus three sigma for that pollutant. Fifty-one data
days (from a total of about 1,300) were eliminated by this
method.
Another approach was also used as a check on the above method of
eliminating certain high values. The minimum values of raw
wastewater concentrations from Plant B for the same four pol-
lutants were compared to the total set of values for the corre-
sponding pollutants. Any day on which the pollutant concentra-
tion exceeded the minimum value selected from raw wastewater
concentrations for that pollutant was discarded. Forty-five days
of data were eliminated by that procedure. Forty-three days of
data in common were eliminated by other procedures. Since common
engineering practice (mean plus 3 sigma) and logic (treated waste
should be less than raw waste) seem to coincide, the data base
with the 51 spurious data days eliminated is the basis for all
further analysis. Range, mean, standard deviation and mean plus
two standard deviations are shown in Tables VII-17 and VII-18 for
Cr, Cu, Ni, Zn, and Fe.
The Plant B data were separated into 1979, 1978, and total data
base (six years) segments. With the statistical analysis from
Plant A for 1978 and 1979 this in effect created five data sets
in which there is some overlap between the individual years and
total data sets from Plant B. By comparing these five parts it
is apparent that they are quite similar and all appear to be from
the same family of numbers. The largest mean found among the
five data sets for each pollutant was selected as the long-term
mean for LS&F technology and is used as the LS&F mean in Table
VII-20.
Plant C data were used as a basis for cadmium removal performance
and as a check on the zinc values derived from plants A and B.
The cadmium data is displayed in Table VII-19 and is incorporated
275
-------
into Table VII-20 for LS&F. The zinc data were analyzed for com-
pliance with the one-day and 30-day values in Table VII-21; no
zinc value of the 103 data points exceeded the one-day zinc value
of 1.02 mg/1. The 103 data points were separated into blocks of
30 points and averaged. Each of the three full 30-day averages
was less than the Table VII-21 value of 0.31 mg/1. Additionally,
the Plant C raw wastewater pollutant concentrations (Table VII-
19) are well within the range of raw wastewater concentrations of
the combined metals data base (Table VI1-15), further supporting
the conclusion that Plant C wastewater data is compatible with
similar data from plants A and B.
Concentration values for regulatory use are displayed in Table
VII-20. Mean one-day, ten-day, and 30-day values for L&S for
nine pollutants were taken from Table VII-14; the remaining L&S
values were developed using the mean values in Table VII-14 and
the mean variability factors discussed above.
LS&F mean values for Cd, Cr, Ni, Zn, and Fe are derived from
plants A, B, and C as discussed above. One, ten, and 30-day
values are derived by applying the variability factor developed
from the pooled data base for the specific pollutant to the mean
for that pollutant. Other LS&F values are calculated using the
long-term average or mean and the appropriate variability fac-
tors. Mean values for LS&F for pollutants not already discussed
are derived by reducing the L&S mean by one-third. The one-third
reduction was established after examining the percent reduction
in concentrations going from L&S to LS&F data for Cd, Cr, Ni, Zn,
and Fe. The average reduction is 0.3338 or one-third.
Copper levels achieved at plants A and B may be lower than gener-
ally achievable because of the high iron content and low copper
content of the raw wastewaters. Therefore, the mean concentra-
tion value achieved is not used; LS&F mean used is derived from
the L&S technology.
L&S cyanide mean levels are ratioed to one-day, ten-day, and 30-
day values using mean variability factors. LS&F mean cyanide is
calculated by applying the ratios of removals for L&S and LS&F as
discussed previously for LS&F metals limitations. The cyanide
performance was arrived at by using the average metal variability
factors. The treatment method used here is cyanide precipita-
tion. Because cyanide precipitation is limited by the same
physical processes as the metal precipitation, it is expected
that the variabilities will be similar. Therefore, the average
of the metal variability factors has been used as a basis for
calculating the cyanide one-day, ten-day, and 30-day average
treatment effectiveness values.
276
-------
The filter performance for removing TSS as shown in Table VI1-8
yields a mean effluent concentration of 2.61 mg/1 and calculates
to a ten-day average of 4.33, 30-day average of 3.36 mg/1; a one-
day maximum of 8.88. These calculated values more than amply
support the classic values of 10 and 15, respectively, which are
used for LS&F.
Although iron was reduced in some LS&F operations, some facili-
ties using that treatment introduce iron compounds to aid settl-
ing. Therefore, the one-day, ten-day, and 30-day values for iron
at LS&F were held at the L&S level so as to not unduly penalize
the operations which use the relatively less objectionable iron
compounds to enhance removals of toxic metals.
Subsequent to proposal, three commenters criticized the use of
the combined metals data base (CMDB) to determine treatment
effectiveness for lime and settle treatment. One commmenter com-
plained about the small size of the data base and the statistical
methods used in analyzing it. Specifically, the commmenter
complained that the data base was too limited to reflect the
effectiveness of lime and settle treatment and that variability
was ill-defined by the available data. In addition, this com-
menter criticized the use of a lognormal basis to model the data,
the use of a bessel function, and the methods used to estimate
variability. The commenter recommended that EPA use the elec-
troplating (metal finishing) data base as an alternative.
Another commenter criticized the inclusion of specific data
points in the CMDB because they did not meet the pH concentration
requirements set by the Agency, and questioned the representa-
tiveness of the copper forming wastewaters treated by the copper
forming plants in the data base. A third commenter questioned
the achievability of specific metal concentrations considering
the spread of minimum solubilities at a range of pH values.
The Agency used the largest available data base that was statis-
tically homogeneous and which represented good operation of lime
and settle treatment systems. This data base was analyzed using
widely known, state-of-the-art statistical procedures for esti-
mating the necessary mean and maximum (99th percentile) values.
A lognormal distribution was used because it provides a satisfac-
tory fit to effluent data under a wide range of circumstances.
The use of lognormal distribution and pooled variance among
plants is an appropriate method for analyzing this type of data.
A full discussion of the statistical methods used in the analysis
of the combined metals data base is in the document entitled A
Statistical Analysis of the Combined Metals Industries Effluent
Data, which is in the public record supporting this regulation.
277
-------
The Agency points out that the electroplating (metal finishing)
data were determined not to be homogeneous and were removed from
the combined data base. As such, electroplating data are not
appropriate for determining lime and settle treatment effective-
ness for the copper forming category.
The Agency carefully examined the data points which industry
criticized as being incorrectly included in the combined metals
data base. Of the four copper forming plants in the combined
metals data base, four data days show a pH below 7.0. In elimi-
nating data from use in the data base, a pH editing rule which
excludes data in cases where the pH is below 7.0 for extended
periods of time (i.e., over two hours) was used. The time
periods of low pH for the points in question cannot be determined
from existing data; however, because large amounts of metals were
removed and low effluent concentrations were being achieved, the
pH at the point of precipitation necessarily had to be well above
pH 7.0. The reason for the effluent pH falling below 7.0 cannot
be determined from the available data, but it is presumed to be a
pH rebound. This phenomenon is often encountered when a slow
reacting acidic material is neutralized or reacts late in the
treatment cycle. The Agency believes that the lime and settle
process was being operated in an acceptable manner and the data
should be retained in the CMDB. The commenter complained that
two data points which were included in the data base should have
been excluded because their influent copper concentrations were
less than their effluent copper concentrations. In the case of
one of these points, the comment was due to a typographical error
in the development document which has been corrected; the raw
concentration was in fact greater than the effluent concentra-
tion. As for the second data point, the comment is correct with
regard to the copper concentrations; however; this point was not
used to determine the CMDB treatability limit for copper.
In response to the comment about the representativeness of sam-
pled plants, the Agency points out that copper forming operations
produce three types of wastewaters which are similar regardless
of the associated forming operation; rinse waters from surface
treatment, oily emulsions, and contact cooling waters. All of
these types of wastewaters are contained in the wastewaters of
the copper forming plants in the data base and thus, the plants
used are representative of wastewaters generated in the category.
In response to the theoretical question about achievability of
specific metal concentrations, our treatment effectiveness values
are based on observed performance of treatment systems rather
than theoretical calculations. Therefore, theoretical solubility
of pollutants alone is not relevant and our treatment effective-
ness data do reflect actual treatment performance for a wide
278
-------
range of metals. We believe that the actual performance data in
the CMDB reflect these theoretical considerations.
The Agency performed a number of evaluations to confirm and
establish the use of the combined metals data base. We looked at
the data from the four copper forming plants alone to examine
treatment effectiveness. Treatment effectiveness values from
these copper forming plants were compared to the values contained
in the combined metals data base. These values were determined
using the same statistical methods discussed earlier in this sec-
tion. The values determined in this manner were essentially the
same as the corresponding CMDB values. This supports the deter-
mination that the combined metals data base is. a good representa-
tion of the performance that can be achieved in the copper
forming category.
MINOR TECHNOLOGIES
Several other treatment technologies were considered for possible
application in BPT or BAT. These technologies are presented here
with a full discussion for most of them. A few are described
only briefly because of limited technical development.
9. Carbon Adsorption
The use of activated carbon to remove dissolved organics from
water and wastewater is a long demonstrated technology. It is
one of the most efficient organic removal processes available.
This sorption process is reversible, allowing activated carbon to
be regenerated for reuse by the application of heat and steam or
solvent. Activated carbon has also proved to be an effective
adsorbent for many toxic metals, including mercury. Regeneration
of carbon which has adsorbed significant amounts of metals,
however, may be difficult.
The term activated carbon applies to any amorphous form of carbon
that has been specially treated to give high adsorption capaci-
ties. Typical raw materials include coal, wood, coconut shells,
petroleum base residues, and char from sewage sludge pyrolysis.
A carefully controlled process of dehydration, carbonization, and
oxidation yields a product which is called activated carbon.
This material has a high capacity for adsorption due primarily to
the large surface area available for adsorption, 500 to 1,500
sizes generally range from 10 to 100 angstroms in radius.
Activated carbon removes contaminants from water by the process
of adsorption, or the attraction and accumulation of one sub-
stance on the surface of another. Activated carbon preferen-
tially adsorbs organic compunds over other species and, because
279
-------
of this selectivity, is particularly effective in removing
organic compounds from aqueous solution.
Carbon adsorption requires preliminary treatment to remove excess
suspended solids, oils, and greases. Suspended solids in the
influent should be less than 50 mg/1 to minimize backwash
requirements; a downflow carbon bed can handle much higher levels
(up to 2,000 mg/1), but requires frequent backwashing. Backwash-
ing more than two or three times a day is not desirable; at 50
mg/1 suspended solids, one backwash will suffice. Oil and grease
should be less than about 10 mg/1. A high level of dissolved
inorganic material in the influent may cause problems with
thermal carbon reactivation (i.e., scaling and loss of activity)
unless appropriate preventive steps are taken. Such steps might
include pH control, softening, or the use of an acid wash on the
carbon prior to reactivation.
Activated carbon is available in both powdered and granular form.
A flow diagram of activated carbon treatment and regeneration is
shown in Figure VI1-20. A schematic of an individual adsorption
column is shown in Figure VII-21. Powdered carbon is less expen-
sive per unit weight and may have slightly higher adsorption
capacity, but it is more difficult to handle and to regenerate.
Application and Performance. Isotherm tests have indicated that
activated carbon is very effective in adsorbing 65 percent of the
toxic organic pollutants and is reasonably effective for another
22 percent. Specifically, activated carbon is very effective in
removing 2,4-dimethylphenol, fluoranthene, isophorone, naphthal-
ene, all phthalates, and phenanthrene. Activated carbon is
reasonably effective on 1,1,1-trichloroethane, 1,1-
dichloroethane, phenol, and toluene.
Table VII-21 summarizes the treatment effectiveness for most of
the toxic organic pollutants by activated carbon as compiled by
EPA. Table VI1-22 summarizes classes of organic compounds
together with samples of organics that are readily adsorbed on
carbon. Table VII-23 lists the effectiveness of activated carbon
in removing seven toxic organic pollutants from actual manufac-
turing process wastewater streams in the nonferrous metals indus-
tries and foundry industries that are very similar to copper
forming wastewater streams.
Advantages and Limitations. The major benefits of carbon
treatment include applicability to a wide variety of organics and
high removal efficiency. Inorganics such as cyanide, chromium,
and mercury are also removed effectively. Variations in
concentration and flow rate are well tolerated. The system is
compact, and recovery of adsorbed materials is sometimes
practical. However, destruction of adsorbed compounds often
280
-------
occurs during thermal regeneration. If carbon cannot be
thermally regenerated, it must be disposed of along with any
adsorbed pollutants. The capital and operating costs of thermal
regeneration are relatively high. Cost surveys show that thermal
regeneration is generally economical when carbon usage exceeds
about 1,000 Ibs/day. Carbon cannot remove low molecular weight
or highly soluble organics. It also has a low tolerance for
suspended solids, which must be removed in most systems to at
least 50 mg/1 in the influent water.
Operational Factors. Reliability: This system should be very
reliable with upstream protection and proper operation and
maintenance procedures.
Maintainability: This system requires periodic regeneration or
replacement of spent carbon and is dependent upon raw waste load
and process efficiency.
Solid Waste Aspects: Solid waste from this process is contami-
nated activated carbon that requires disposal. Carbon that
undergoes regenerat ion reduces the sol id waste problem by
reducing the frequency of carbon replacement.
Demonstration Status. Carbon adsorption systems have been
demonstrated to be practical and economical in reducing COD, BOD,
and related parameters in secondary municipal and industrial
wastewaters; in removing toxic or refractory organics from
isolated industrial wastewaters; in removing and recovering
certain organics from wastewaters; and in removing, and sometimes
recovering, selected inorganic chemicals from aqueous wastes.
Carbon adsorption is a viable and economic process for organic
waste streams containing up to 1 to 5 percent of refractory or
toxic organics. Its applicability for removal of inorganics such
as metals has also been demonstrated.
10. Flotation
Flotation is the process of causing particles such as metal
hydroxides or oil to float to the surface of a tank where they
can be concentrated and removed. This is accomplished by releas-
ing gas bubbles which attach to the solid particles, increasing
their buoyancy and causing them to float. In principle, this
process is the opposite of sedimentation. Figure VII-22 shows
one type of flotation system.
Flotation is used primarily in the treatment of wastewater
streams that carry heavy loads of finely divided suspended solids
or oil. Solids having a specific gravity only slightly greater
than 1.0, which would require abnormally long sedimentation
times, may be removed in much less time by flotation.
281
-------
This process may be performed in several ways: foam, dispersed
air, dissolved air, gravity, and vacuum flotation are the most
commonly used techniques. Chemical additives are often used to
enhance the performance of the flotation process.
The principal difference among types of flotation is the method
of generating the minute gas bubbles (usually air) in a suspen-
sion of water and small particles. Chemicals may be used to
improve the efficiency with any of the basic methods. The fol-
lowing paragraphs describe the different flotation techniques and
the method of bubble generation for each process.
Froth Flotation - Froth flotation is based on differences in the
physiochemical properties in various particles. Wettability and
surface properties affect the ability of the particles to attach
themselves to gas bubbles in an aqueous medium. In froth flota-
tion, air is blown through the solution containing flotation
reagents. The particles with water repellant surfaces stick to
air bubbles as they rise and are brought to the surface. A
mineralized froth layer, with mineral particles attached to air
bubbles, is formed. Particles of other minerals which are read-
ily wetted by water do not stick to air bubbles and remain in
suspension.
Dispersed Air Flotation - In dispersed air flotation, gas bubbles
are generated by introducing the air by means of mechanical agi-
tation with impellers or by forcing air through porous media.
Dispersed air flotation is used mainly in the metallurgical
industry.
Dissolved Air Flotation - In dissolved air flotation, bubbles are
produced by releasing air from a superstaturated solution under
relatively high pressure. There are two types of contact between
the gas bubbles and particles. The first type is predominant in
the flotation of flocculated materials and involves the entrap-
ment of rising gas bubbles in the flocculated particles as they
increase in size. The bond between the bubble and particle is
one of physical capture only. The second type of contact is one
of adhesion. Adhesion results from the intermolecular attraction
exerted at the interface between the solid particle and the gase-
ous bubble.
Vacuum Flotation - This process consists of saturating the waste-
water with air either directly in an aeration tank, or by permit-
ting air to enter on the suction of a wastewater pump. A partial
vacuum is applied, which causes the dissolved air to come out of
solution as minute bubbles. The bubbles attach to solid parti-
cles and rise to the surface to form a scum blanket, which is
normally removed by a skimming mechanism. Grit and other heavy
282
-------
solids that settle to the bottom are generally raked to a central
sludge pump for removal. A typical vacuum flotation unit con-
sists of a covered cylindrical tank in which a partial vacuum is
maintained. The tank is equipped with scum and sludge removal
mechanisms. The floating material is continuously swept to the
tank periphery, automatically discharged into a scum trough, and
removed from the unit by a pump also under partial vacuum.
Auxiliary equipment includes an aeration tank for saturating the
wastewater with air, a tank with a short retention time for
removal of large bubbles, vacuum pumps, and sludge pumps.
Application and Performance. Flotation is used primarily in the
treatment of wastewater streams that carry heavy loads of finely
divided suspended solids or oil. Solids having a specific
gravity only slightly greater than 1.0, which would require
abnormally long sedimentation times, may be removed in much less
time by flotation.
The primary variables for flotation design are pressure, feed
solids concentration, and retention period. The suspended solids
in the effluent decrease, and the concentration of solids in the
float increases, with increasing retention period. When the
flotation process is used primarily for clarification, a reten-
tion period of 20 to 30 minutes is adequate for separation and
concentration.
Advantages and Limitations. Some advantages of the flotation
process are the high levels of solids separation achieved in many
applications, the relatively low energy requirements, and the
adaptability to meet the treatment requirements of different
waste types. Limitations of flotation are that it often requires
addition of chemicals to enhance process performance and that it
generates large quantities of solid waste.
Operational Factors. Reliability: Flotation systems normally
are very reliable with proper maintenance of the sludge collector
mechanism and the motors and pumps used for aeration.
Maintainability: Routine maintenance is required on the pumps
and motors. The sludge collector mechanism is subject to possi-
ble corrosion or breakage and may require periodic replacement.
Solid Waste Aspects: Chemicals are commonly used to aid the
flotation process by creating a surface or a structure that can
easily adsorb or entrap air bubbles. Inorganic chemicals, such
as the aluminum and ferric salts, and activated silica, can bind
the particulate matter together and create a structure that can
entrap air bubbles. Various organic chemicals can change the
nature of either the air-liquid interface or the solid-liquid
interface, or both. These compounds usually collect on the
283
-------
interface to bring about the desired changes. The added chemi-
cals plus the particles in solution combine to form a large
volume of sludge which must be further treated or properly
disposed.
Demonstration Status. Flotation is a fully developed process and
is readily available for the treatment of a wide variety of
industrial waste streams. Dissolved air flotation technology is
used by can manufacturing plants to remove oil and grease in the
wastewater from can wash lines. It is not currently used to
treat copper forming wastewaters.
11. Centrifuqation
Centrifugation is the application of centrifugal force to sepa-
rate solids and liquids in a liquid-solid mixture or to effect
concentration of the solids. The application of centrifugal
force is effective because of the density differential normally
found between the insoluble solids and the liquid in which they
are contained. As a waste treatment procedure, centrifugation is
most often applied to dewatering of sludges. One type of centri-
fuge is shown in Figure VII-23.
There are three common types of centrifuges: the disc, basket,
and conveyor type. All three operate by removing solids under
the influence of centrifugal force. The fundamental difference
between the three types is the method by which solids are col-
lected in and discharged from the bowl.
In the disc centrifuge, the sludge feed is distributed between
narrow channels that are present as spaces between stacked con-
ical discs. Suspended particles are collected and discharged
continuously through small orifices in the bowl wall. The clar-
ified effluent is discharged through an overflow weir.
A second type of centrifuge which is useful in dewatering sludges
is the basket centrifuge. In this type of centrifuge, sludge
feed is introduced at the bottom of the basket, and solids col-
lect at the bowl wall while clarified effluent overflows the lip
ring at the top. Since the basket centrifuge does not have pro-
vision for continuous discharge of collected cake, operation
requires interruption of the feed for cake discharge for a minute
or two in a 10 to 30 minute overall cycle.
The third type of centrifuge commonly used in sludge dewatering
is the conveyor type. Sludge is fed through a stationary feed
pipe into a rotating bowl in which the solids are settled out
against the bowl wall by centrifugal force. From the bowl wall,
they are moved by a screw to the end of the machine, at which
point they are discharged. The liquid effluent is discharged
J 284
-------
through ports after passing the length of the bowl under cen-
trifugal force.
Application and Performance. Virtually all industrial waste
treatment systems producing sludge can use centrifugation to
dewater it. Centrifugation is currently being used by a wide
range of industrial concerns.
The performance of sludge dewatering by centrifugation depends on
the feed rate, the rotational velocity of the drum, and the
sludge composition and concentration. Assuming proper design and
operation, the solids content of the sludge can be increased to
20 to 35 percent.
Advantages and Limitations. Sludge dewatering centrifuges have
minimal space requirements and show a high degree of effluent
clarification. The operation is simple, clean, and relatively
inexpensive. The area required for a centrifuge system
installation is less than that required for a filter system or
sludge drying bed of equal capacity, and the initial cost is
lower.
Centrifuges have a high power cost that partially offsets the low
initial cost. Special consideration must also be given to pro-
viding sturdy foundations and soundproofing because of the vibra-
tion and noise that result from centrifuge operation. Adequate
electrical power must also be provided since large motors are
required. The major difficulty encountered in the operation of
centrifuges has been the disposal of the concentrate which is
relatively high in suspended, non-settling solids.
Operational Factors. Reliability: Centrifugation is highly
reliable with proper control of factors such as sludge feed, con-
sistency, and temperature. Pretreatment such as grit removal and
coagulant addition may be necessary, depending on the composition
of the sludge and on the type of centrifuge employed.
Maintainability: Maintenance consists of periodic lubrication,
cleaning, and inspection. The frequency and degree of inspection
required varies depending on the type of sludge solids being
dewatered and the maintenance service conditions. If the sludge
is abrasive, it is recommended that the first inspection of the
rotating assembly be made after approximately 1,000 hours of
operation. If the sludge is not abrasive or corrosive, then the
initial inspection might be delayed. Centrifuges not equipped
with a continuous sludge discharge system require periodic
shutdowns for manual sludge cake removal.
Solid Waste Aspects: Sludge dewatered in the centrifugation pro-
cess may be disposed of by landfill. The clarified effluent
285
-------
(centrate), if high in dissolved or suspended solids, may require
further treatment prior to discharge.
Demonstration Status. Centrifugation is currently used in a
great many commercial applications to dewater sludge. Work is
underway to improve the efficiency, increase the capacity, and
lower the costs associated with centrifugation.
12. Coalescing
The basic principle of coalescence involves the preferential
wetting of a coalescing medium by oil droplets which accumulate
on the medium and then rise to the surface of the solution as
they combine to form larger particles. The most important
requirements for coalescing media are wettability for oil and
large surface area. Monofilament line is sometimes used as a
coalescing medium.
Coalescing stages may be integrated with a wide variety of grav-
ity oil separation devices, and some systems may incorporate
several coalescing stages. In general, a preliminary oil skim-
ming step is desirable to avoid overloading the coalescer.
One commercially marketed system for oily waste treatment com-
bines coalescing with inclined plate separation and filtration.
In this system, the oily wastes flow into an inclined plate
settler. This unit consists of a stack of inclined baffle plates
in a cylindrical container with an oil collection chamber at the
top. The oil droplets rise and impinge upon the undersides of
the plates. They then migrate upward to a guide rib that directs
the oil to the oil collection chamber, from which oil is dis-
charged for reuse or disposal.
The oily water continues on through another cylinder containing
replaceable filter cartridges that remove suspended particles
from the waste. From there the wastewater enters a final cylin-
der in which the coalescing material is housed. As the oily
water passes through the many small, irregular, continuous
passages in the coalescing material, the oil droplets coalesce
and rise to an oil collection chamber.
Application and Performance. Coalescing is used to treat oily
wastes that do not separate readily in simple gravity systems.
The three stage system described above has achieved effluent
concentrations of 10 to 15 mg/1 oil and grease from raw waste
concentrations of 1,000 mg/1 or more.
Advantages and Limitations. coalescing allows removal of oil
droplets too finely dispersed for conventional gravity
separation-skimming technology. It also can significantly reduce
286
-------
the residence times (and therefore separator volumes) required to
achieve separation of oil from some wastes. Because of its sim-
plicity, coalescing provides generally high reliability and low
capital and operating costs. Coalescing is not generally effec-
tive in removing soluble or chemically stabilized emulsified
oils. To avoid plugging, coalescers must be protected by pre-
treatment from the very high concentrations of free oil and
grease and suspended solids. Frequent replacement of prefilters
may be necessary when raw waste oil concentrations are high.
Operational Factors. Reliability: Coalescing is inherently
highly reliable since there are no moving parts and the coalesc-
ing substrate (monofilament, etc.) is inert in the process and
therefore not subject to frequent regeneration or replacement
requirements. Large loads or inadequate preliminary treatment,
however, may result in plugging or bypass of coalescing stages.
Maintainability: Maintenance requirements are generally limited
to replacement of the coalescing medium on an infrequent basis.
Solid Waste Aspects: No appreciable solid waste is generated by
this process.
Demonstration Status. Coalescing has been fully demonstrated in
industries generating oily wastewater. A few are known to be in
use at copper forming plants.
13. Evaporation
Evaporation is a concentration process. Water is evaporated from
a solution, increasing the concentration of solute in the remain-
ing solution. If the resulting water vapor is condensed back to
liquid water, the evaporation-condensation process is called dis-
tillation. However, to be consistent with industry terminology,
evaporation is used in this report to describe both processes.
Both atmospheric and vacuum evaporation are commonly used in
industry today. Specific evaporation techniques are shown in
Figure VI1-27 and discussed below.
Atmospheric evaporation could be accomplished simply by boiling
the liquid. To aid evaporation, heated liquid is sprayed on an
evaporation surface, and air is blown over the surface and subse-
quently released to the atmosphere. Thus, evaporation occurs by
numidification of the air stream, similar to a drying process.
Equipment for carrying out atmospheric evaporation is quite
similar for most applications. The major element is generally a
packed column with an accumulator bottom. Accumulated wastewater
is pumped from the base of the column, through a heat exchanger,
and back into the top of the column, where it is sprayed into the
packing. At the same time, air drawn upward through the packing
287
-------
by a fan is heated as it contacts the hot liquid. The liquid
partially vaporizes and humidifies the air stream. The fan then
blows the hot, humid air to the outside atmosphere. A scrubber
is often unnecessary because the packed column itself acts as a
scrubber.
Another form of atmospheric evaporator also works on the air
humidification principle, but the evaporated water is recovered
for reuse by condensation. These air humidification techniques
operate well below the boiling point of water and can utilize
waste process heat to supply the energy required.
In vacuum evaporation, the evaporation pressure is lowered to
cause the liquid to boil at reduced temperatures. All of the
water vapor is condensed and, to maintain the vacuum condition,
noncondensible gases (air in particular) are removed by a vacuum
pump. Vacuum evaporation may be either single or double effect.
In double effect evaporation, two evaporators are used, and the
water vapor from the first evaporator (which may be heated by
steam) is used to supply heat to the second evaporator. As it
supplies heat, the water vapor from the first evaporator con-
denses. Approximately equal quantities of wastewater are evapo-
rated in each unit; thus, the double effect system evaporates
twice the amount of water that a single effect system does, at
nearly the same cost in energy but with added capital cost and
complexity. The double effect technique is thermodynamically
possible because the second evaporator is maintained at lower
pressure (higher vacuum) and, therefore, lower evaporation tem-
perature. Another means of increasing energy efficiency is vapor
recompression (thermal or mechanical), which enables heat to be
transferred from the condensing water vapor to the evaporating
wastewater. Vacuum evaporation equipment may be classified as
submerged tube or climbing film evaporation units.
In the most commonly used submerged tube evaporator, the heating
and condensing coil are contained in a single vessel to reduce
capital cost. The vacuum in the vessel is maintained by an
eductor-type pump, which creates the required vacuum by the flow
of the condenser cooling water through a venturi. Wastewater
accumulates in the bottom of the vessel, and it is evaporated by
means of submerged steam coils. The resulting water vapor con-
denses as it contacts the condensing coils in the top of the
vessel. The condensate then drips off the condensing coils into
a collection trough that carries it out of the vessel. Con-
centrate is removed from the bottom of the vessel.
The major elements of the climbing film evaporator are the evapo-
rator , separator, condenser, and vacuum pump. Wastewater i s
"drawn" into the system by the vacuum so that a constant liquid
level is maintained in the separator. Liquid enters the steam-
288
-------
jacketed evaporator tubes, and part of it evaporates so that a
mixture of vapor and liquid enters the separator. The design of
the separator is such that the liquid is continuously circulated
from the separator to the evaporator. The vapor entering the
separator flows out through a mesh entrainment separator to the
condenser, where it is condensed as it flows down through the
condenser tubes. The condensate, along with any entrained air,
is pumped out of the bottom of the condenser by a liquid ring
vacuum pump. The liquid seal provided by the condensate keeps
the vacuum in the system from being broken.
Application and Performance. Both atmospheric and vacuum
evaporation are used in many industrial plants, mainly for the
concentration and recovery of process solutions. Many of these
evaporators also recover water for rinsing. Evaporation has also
been applied to recovery of phosphate metal-cleaning solutions.
In theory, evaporation should yield a concentrate and a deionized
condensate. Actually, carry-over has resulted in condensate
metal concentrations as high as 10 mg/1, although the usual level
is less than 3 mg/1, pure enough for most final rinses. The con-
densate may also contain organic brighteners and antifoaming
agents. These can be removed with an activated carbon bed, if
necessary. Samples from one plant showed 1,900 mg/1 zinc in the
feed, 4,570 mg/1 in the concentrate, and 0.4 mg/1 in the condens-
ate. Another plant had 416 mg/1 copper in the feed and 21,800
mg/1 in the concentrate. Chromium analysis for that plant indi-
cated 5,060 mg/1 in the feed and 27,500 mg/1 in the concentrate.
Evaporators are available in a range of capacities, typically
from 15 to 75 gph, and may be used in parallel arrangements for
processing of higher flow rates.
Advantages and Limitations. Advantages of the evaporation
process are that it permits recovery of a wide variety of process
chemicals, and it is often applicable to concentration or removal
of compounds which cannot be accomplished by any other means.
The major disadvantage is that the evaporation process consumes
relatively large amounts of energy for the evaporation of water.
The recovery of waste heat from many industrial processes (e.g.,
diesel generators, incinerators, boilers, and furnaces) should be
considered as a source of this heat for a totally integrated
evaporation system. Also, in some cases solar heating could be
inexpensively and effectively applied to evaporation units. For
some applications, preliminary treatment may be required to
remove solids or bacteria which tend to cause fouling in the
condenser or evaporator. The buildup of scale on the evaporator
surfaces reduces the heat transfer efficiency and may present a
maintenance problem or increase operating cost. It has been
demonstrated that fouling of the heat transfer surfaces can be
avoided or minimized for certain dissolved solids by maintaining
289
-------
a seed slurry which provides preferential sites for precipitate
deposition. In addition, low temperature differences in the
evaporator will eliminate nucleate boiling and supersaturation
effects. Steam distillable impurities in the process stream are
carried over with the product water and must be handled by
preliminary or post treatment.
Operational Factors. Reliability: Proper maintenance will ensure
a high degree of reliability for the system. Without such
attention, rapid fouling or deterioration of vacuum seals may
occur, especially when handling corrosive liquids.
Maintainability: Operating parameters can be automatically
controlled. Preliminary treatment may be required, as well as
periodic cleaning of the system. Regular replacement of seals,
especially in a corrosive environment, may be necessary.
Solid Waste Aspects: With only a few exceptions, the process
does not generate appreciable quantities of solid waste.
Demonstration Status. Evaporation is a fully developed, com-
mercially available wastewater treatment system. It is used
extensively to recover plating chemicals in the electroplating
industry and a pilot scale unit has been used in connection with
phosphating of aluminum. Proven performance in silver recovery
indicates that evaporation could be a useful treatment operation
for the photographic industry, as well as for metal finishing.
14. Gravity Sludge Thickening
In the gravity thickening process, dilute sludge is fed from a
primary settling tank or clarifier to a thickening tank where
rakes stir the sludge gently to densify it and to push it to a
central collection well. The supernatant is returned to the
primary settling tank. The thickened sludge that collects on the
bottom of the tank is pumped to dewatering equipment or hauled
away. Figure VI1-28 shows the construction of a gravity
thickener.
Application and Performance. Thickeners are generally used in
facilities where the sludge is to be further dewatered by a
compact mechanical device such as a vacuum filter or centrifuge.
Doubling the solids content in the thickener substantially
reduces capital and operating cost of the subsequent dewatering
device and also reduces cost for hauling. The process is
potentially applicable to almost any industrial plant.
Organic sludges from sedimentation units of 1 to 2 percent solids
concentration can usually be gravity thickened to 6 to 10 per-
cent; chemical sludges can be thickened to 4 to 6 percent.
290
-------
Advantages and Limitations. The principal advantage of a gravity
sludge thickening process is that it facilitates further sludge
dewatering. Other advantages are high reliability and minimum
maintenance requirements.
Limitations of the sludge thickening process are its sensitivity
to the flow rate through the thickener and the sludge removal
rate. These rates must be low enough not to disturb the
thickened sludge.
Operational Factors. Reliability: Reliability is high with
proper design and operation. A gravity thickener is designed on
the basis of square feet per pound of solids per day, in which
the required surface area is related to the solids entering and
leaving the unit. Thickener area requirements are also expressed
in terms of mass loading, kilograms of solids per square meter
per day (Ibs/sq ft/day).
Maintainability: Twice a year, a thickener must be shut down for
lubrication of the drive mechanisms. Occasionally, water must be
pumped back through the system in order to clear sludge pipes.
Solid Waste Aspects: Thickened sludge from a gravity thickening
process will usually require further dewatering prior to dispo-
sal, incineration, or drying. The clear effluent may be recircu-
lated in part, or it may be subjected to further treatment prior
to discharge. *
Demonstration Status. Gravity sludge thickeners are used
throughout industry to reduce sludge water content to a level
where the sludge may be efficiently handled. Further dewatering
is usually practiced to minimize costs of hauling the-sludge to
approved landfill areas.
15. Ion Exchange
Ion exchange is a process in which ions, held by electrostatic
forces to charged functional groups on the surface of the ion
exchange resin, are exchanged for ions of similar charge from the
solution in which the resin is immersed. This is classified as a
sorption process because the exchange occurs on the surface of
the resin, and the exchanging ion must undergo a phase transfer
from solution phase to solid phase. Thus, ionic contaminants in
a waste stream can be exchanged for the harmless ions of the
resin.
Although the precise technique may vary slightly according to the
application involved, a generalized process description follows.
The wastewater stream being treated passes through a filter to
remove any solids, then flows through a cation exchanger which
291
-------
contains the ion exchange resin. Here, metallic impurities such
as copper, iron, and trivalent chromium are retained. The stream
then passes through the anion exchanger and its associated resin.
Hexavalent chromium (in the form of chromate or dichromate), for
example, is retained in this stage. If one pass does not reduce
the contaminant levels sufficiencly, the stream may then enter
another series of exchangers. Many ion exchange systems are
equipped with more than one set of exchangers for this reason.
The other major portion of the ion exchange process concerns the
regeneration of the resin, which now holds those impurities
retained from the waste stream. An ion exchange unit with in-
place regeneration is shown in Figure VI1-29. Metal ions such as
nickel are removed by an acid, cation exchange resin, which is
regenerated with hydrochloric or sulfuric acid, replacing the
metal ion with one or more hydrogen ions. Anions such as dichro-
mate are removed by a basic anion exchange resin, which is regen-
erated with sodium hydroxide, replacing the anion with one or
more hydroxyl ions. The three principal methods employed by
industry for regenerating the spent resin are:
(A) Replacement Service: A regeneration service replaces
the spent resin with regenerated resin, and regenerates
the spent resin at its own facility. The service then
has the problem of treating and disposing of the spent
regenerant.
(B) In-Place Regeneration: Some establishments may find it
less expensive to do their own regeneration. The spent
resin column is shut down for perhaps an hour, and the
spent resin is regenerated. This results in one or
more waste streams which must be treated in an appro-
priate manner. Regeneration is performed as the resins
require it, usually every few months.
(C) Cyclic Regeneration: In this process, the regeneration
of the spent resins takes place within the ion exchange
unit itself in alternating cycles with the ion removal
process. A regeneration frequency of twice an hour is
typical. This very short cycle time permits operation
with a very small quantity of resin and with fairly
concentrated solutions, resulting in a very compact
system. Again, this process varies according to appli-
cation, but the regeneration cycle generally begins
with caustic being pumped through the anion exchanger,
carrying out hexavalent chromium, for example, as
sodium dichromate. The sodium dichromate stream then
passes through a cation exchanger, converting the
sodium dichromate to chromic acid. After concentration
by evaporation or other means, the chromic acid can be
292
-------
returned to the process line. Meanwhile, the cation
exchanger is regenerated with sulfuric acid, resulting
in a waste acid stream containing the metallic impuri-
ties removed earlier. Flushing the exchangers with
water completes the cycle. Thus, the wastewater is
purified and, in this example, chromic acid is recov-
ered. The ion exchangers, with newly regenerated
resin, then enter the ion removal cycle again.
Application and Performance. The list of pollutants for which
the ion exchange system has proven effective includes aluminum,
arsenic, cadmium, chromium (hexavalent and trivalent), copper,
cyanide, gold, iron, lead, manganese, nickel, selenium, silver,
tin, zinc, and others. Thus, it can be applied to a wide variety
of industrial concerns. Because of the heavy concentrations of
metals in their wastewater, the metal finishing industries
utilize ion exchange in several ways. As an end-of-pipe
treatment, ion exchange is certainly feasible, but its greatest
value is in recovery applications. It is commonly used as an
integrated treatment to recover rinse water and process
chemicals. Some electroplating facilities use ion exchange to
concentrate and purify plating baths. Also, many industrial
concerns, including a number of aluminum forming plants, use ion
exchange to reduce salt concentrations in incoming water sources.
Ion exchange is highly efficient at recovering metal-bearing
solutions. Recovery of chromium, nickel, phosphate solution, and
sulfuric acid from anodizing is common. A chromic acid recovery
efficiency of 99.5 percent has been demonstrated. Typical data
for purification of rinse water are displayed in Table VII-24.
Advantages and Limitations. Ion exchange is a versatile
technology applicable to a great many situations. This
flexibility, along with its compact nature and performance, makes
ion exchange a very effective method of wastewater treatment.
However, the resins in these systems can prove to be a limiting
factor. The thermal limits of the anion resins, generally in the
vicinity of 60° C, could prevent its use in certain situations.
Similarly, nitric acid, chromic acid, and hydrogen peroxide can
all damage the resins, as will iron, manganese, and copper when
present with sufficient concentrations of dissolved oxygen.
Removal of a particular trace contaminant may be uneconomical
because of the presence of other ionic species that are
preferentially removed. The regeneration of the resins presents
its /own problems. The cost of the regenerative chemicals can be
high. In addition, the waste streams originating from the
regeneration process are extremely high in pollutant
concentrations, although low in volume. These must be further
processed for proper disposal.
293
-------
Operational Factors. Reliability: With the exception of
occasional clogging or fouling of the resins, ion exchange has
proved to be a highly dependable technology.
Maintainability: Only the normal maintenance of pumps, valves,
piping, and other hardware used in the regeneration process is
required.
Solid Waste Aspects: Few, if any, solids accumulate within the
ion exchangers, and those which do appear are removed by the
regeneration process. Proper prior treatment and planning can
eliminate solid buildup problems altogether. The brine resulting
from regeneration of the ion exchange resin most usually must be
treated to remove metals before discharge. This can generate
solid waste.
Demonstration Status. All of the ion exchange applications
discussed inthis section are in commercial use, and industry
sources estimate the number of ion exchange units currently in
the field at well over 120. The research and development in ion
exchange is focusing on improving the quality and efficiency of
the resins, rather than new applications. Work is also being
done on a continuous regeneration process whereby the resins are
contained on a fluid-transfusible belt. The belt passes through
a compartmented tank with ion exchange, washing, and regeneration
sections. The resins are therefore continually used and regen-
erated. No such system, however, has been reported beyond the
pilot stage.
16. Insoluble Starch Xanthate
Insoluble starch xanthate is essentially an ion exchange medium
used to remove dissolved heavy metals from wastewater. The water
may then either be reused (recovery application) or discharged
(end-of-pipe application). In a commercial electroplating
operation, starch xanthate is coated on a filter medium. Rinse
water containing dragged out heavy metals is circulated through
the filters and then reused for rinsing. The starch-heavy metal
complex is disposed of and replaced periodically. Laboratory
tests indicate that recovery of metals from the complex is
feasible, with regeneration of the starch xanthate. Besides
electroplating, starch xanthate is potentially applicable to
aluminum forming, coil coating, porcelain enameling, copper
forming, and any other industrial plants where dilute metal
wastewater streams are generated. Its present use is limited to
one electroplating plant.
294
-------
17. Peat Adsorption
Peat moss is a complex natural organic material containing lignin
and cellulose as major constituents. These constituents, partic-
ularly lignin, bear polar functional groups, such as alcohols,
aldehydes, ketones, acids, phenolic hydroxides, and ethers, that
can be involved in chemical bonding. Because of the polar nature
of the material, its adsorption of dissolved solids such as
transition metals and polar organic molecules is quite high.
These properties have led to the use of peat as an agent for the
purification of industrial wastewater.
Peat adsorption is a "polishing" process which can achieve very
low effluent concentrations for several pollutants. If the con-
centrations of pollutants are above 10 mg/1, then peat adsorption
must be preceded by pH adjustment for metals precipitation and
subsequent clarification. Pretreatment is also required for
chromium wastes using ferric chloride and sodium sulfide. The
wastewater is then pumped into a large metal chamber called a
kier which contains a layer of peat through which the waste
stream passes. The water flows to a second kier for further
adsorption. The wastewater is then ready for discharge. This
system may be automated or manually operated.
Application and Performance. Peat adsorption can be used in
copper forming plants for removal of residual dissolved metals
from clarifier effluent. Peat moss may be used to treat waste-
waters containing heavy metals such as mercury, cadmium, zinc,
copper, iron, nickel, chromium, and lead, as well as organic
matter such as oil, detergents, and dyes. Peat adsorption is
currently used commercially at a textile plant, a newsprint
facility, and a metal reclamation operation.
Table VII-25 contains performance figures obtained from pilot
plant studies. Peat adsorption was preceded by pH adjustment for
precipitation and by clarification.
In addition, pilot plant studies have shown that chelated metal
wastes, as well as the chelating agents themselves, are removed
by contact with peat moss.
Advantages and Limitations. The major advantages of the system
include its ability to yield low pollutant concentrations, its
broad scope in terms of the pollutants eliminated, and its
capacity to accept wide variations of wastewater composition.
Limitations include the cost of purchasing, storing, and dispos-
ing of the peat moss; the necessity for regular replacement of
the peat may lead to high operation and maintenance costs. Also,
295
-------
the pH adjustment must be altered according to the composition of
the waste stream.
Operational Factors. Reliability: The question of long-term
reliability is not yet fully answered. Although the manufacturer
reports it to be a highly reliable system, operating experience
is needed to verify the claim.
Maintainability: The peat moss used in this process soon
exhausts its capacity to adsorb pollutants. At that time, the
kiers must be opened, the peat removed, and fresh peat placed
inside. Although this procedure is easily and quickly accom-
plished, it must be done at regular intervals, or the system s
efficiency drops drastically.
Solid Waste Aspects: After removal from the kier, the spent peat
must be eliminated. If incineration is used, precautions should
be taken to ensure that those pollutants removed from the water
are not released again in the combustion process. Presence of
sulfides in the spent peat, for example, will give rise to sulfur
dioxide in the fumes from burning. The presence of significant
quantities of toxic heavy metals in copper forming wastewater
will in general preclude incineration of peat used in treating
these wastes.
Demonstration Status. Only three facilities currently use
commercial adsorption systems in the United States -a textile
manufacturer, a newsprint facility, and a metal reclamation firm.
No data have been reported showing the use of peat adsorption in
copper forming plants.
18. Membrane Filtration
Membrane filtration is a treatment system for removing precipi-
tated metals from a wastewater stream. It must therefore be
preceded by those treatment techniques which will properly pre-
pare the wastewater for solids removal. Typically, a membrane
filtration unit is preceded by pH adjustment or sulfide addition
for precipitation of the metals. These steps are followed by the
addition of a proprietary chemical reagent which causes the pre-
cipitate to be non-gelatinous, easily dewatered, and highly
stable. The resulting mixture of pretreated wastewater and
reagent is continuously recirculated through a filter module and
back into a recirculation tank. The filter module contains tubu-
lar membranes. While the reagent-metal hydroxide precipitate
mixture flows through the inside of the tubes, the water and any
dissolved salts permeate the membrane. When the recirculating
slurry reaches a concentration of 10 to 15 percent solids, it is
pumped out of the system as sludge.
296
-------
Application and Performance. Membrane filtration appears to be
applicable to any wastewater or process water containing metal
ions which can be precipitated using hydroxide, sulfide, or car-
bonate precipitation. It could function as the primary treatment
system, but also might find application as a polishing treatment
(after precipitation and settling) to ensure continued compliance
with metals limitations. Membrane filtration systems are being
used in a number of industrial applications, particularly in the
metal finishing area. They have also been used for heavy metals
removal in the metal fabrication industry and the paper industry.
The permeate is claimed by one manufacturer to contain less than
the effluent concentrations shown in Table VII-26, regardless of
the influent concentrations. These claims have been largely sub-
stantiated by the analysis of water samples at various plants in
various industries.
In the performance predictions for this technology, pollutant
concentrations are reduced to the levels shown in Table VII-26
unless lower levels are present in the influent stream.
Advantages and Limitations. A major advantage of the membrane
filtration system is that installations can use most of the
conventional end-of-pipe systems that may already be in place.
Removal efficiencies are claimed to be excellent, even with
sudden variation of pollutant input rates; however, the
effectiveness of the membrane filtration system can be limited by
clogging of the filters. Because pH changes in the waste stream
greatly intensify clogging problems, the pH must be carefully
monitored and controlled. Clogging can force the shutdown of the
system and may interfere with production. In addition,
relatively high capital cost of this system may limit its use.
Operational Factors. Reliability: Membrane filtration has been
shown to be a very reliable system, provided that the pH is
strictly controlled. Improper pH can result in the clogging of
the membrane. Also, surges in the flow rate of the waste stream
must be controlled in order to prevent solids from passing
through the filter and into the effluent.
Maintainability: The membrane filters must be regularly moni-
tored, and cleaned or replaced as necessary. Depending on the
composition of the waste stream and its flow rate, frequent
cleaning of the filters may be required. Flushing with hydro-
C2i?rfc acid for six to 2f hours will usually suffice. In
addition, the routine maintenance of pumps, valves, and other
plumbing is required.
Solid Waste Aspects: When the recirculating reagent-precipitate
slurry reaches 10 to 15 percent solids, it is pumped out of the
297
-------
system. It can then be disposed of directly to a landfill or it
can undergo a dewatering process. Because this sludge contains
toxic metals, it requires proper disposal.
Demonstration Status. There are more than 25 membrane filtration
systems presently in use on metal finishing and similar
wastewaters. Bench scale and pilot studies are being run in an
attempt to expand the list of pollutants for which this system is
known to be effective. Although there are no data on the use of
membrane filtration in copper forming plants, the concept has
been successfully demonstrated using coil coating plant
wastewater.
19. Reverse Osmosis
The process of osmosis involves the passage of a liquid through a
semipermeable membrane from a dilute to a more concentrated solu-
tion. Reverse osmosis (RO) is an operation in which pressure is
applied to the more concentrated solution, forcing the permeate
to diffuse through the membrane and into the more dilute solu-
tion. This filtering action produces a concentrate and a perme-
ate on opposite sides of the membrane. The concentrate can then
be further treated or returned to the original production opera-
tion for continued use, while the permeate water can be recycled
for use as clean water. Figure VI1-30 depicts a reverse osmosis
system.
As illustrated in Figure VII-31, there are three basic configura-
tions used in commercially available RO modules: tubular,
spiral-wound, and hollow fiber. All of these operate on the
principle described above, the major difference being their
mechanical -and structural design characteristics.
The tubular membrane module uses a porous tube with a cellulose
acetate membrane-lining. A common tubular module consists of a
length of 2.5 cm {1 inch) diameter tube wound on a supporting
spool and encased in a plastic shroud. Feed water is driven into
the tube under pressures varying from 40 to 55 atm (600 to 800
psi). The permeate passes through the walls of the tube and is
collected in a manifold while the concentrate is drained off at
the end of the tube. A less widely used tubular RO module uses a
straight tube contained in a housing, under the same operating
conditions.
Spiral-wound membranes consist of a porous backing sandwiched
between two cellulose acetate membrane sheets and bonded along
three edges. The fourth edge of the composite sheet is attached
to a large permeate collector tube. A spacer screen is then
placed on top of the membrane sandwich and the entire stack is
rolled around the centrally located tubular permeate collector.
298
-------
The rolled up package is inserted into a pipe able to withstand
the high operating pressures employed in this process, up to 55
atm (800 psi) with the spiral-wound module. When the system is
operating, the pressurized product water permeates the membrane
and flows through the backing material to the central collector
tube. The concentrate is drained off at the end of the container
pipe and can be reprocessed or sent to further treatment facili-
ties.
The hollow fiber membrane configuration is made up of a bundle of
polyamide fibers of approximately 0.0075 cm (0.003 in.) OD and
0.043 cm (0.0017 in.) ID. A commonly used hollow fiber module
contains several hundred thousand of the fibers placed in a long
tube, wrapped around a flow screen, and rolled into a spiral.
The fibers are bent in a U-shape and their ends are supported by
an epoxy bond. The hollow fiber unit is operated under 27 atm
(400 psi), the feed water being dispersed from the center of the
module through a porous distributor tube. Permeate flows through
the membrane to the hollow interiors of the fibers and is col-
lected at the ends of the fibers.
The hollow fiber and spiral-wound modules have a distinct advan-
tage over the tubular system in that they are able to load a very
large membrane surface area into a relatively small volume. How-
ever, these two membrane types are much more susceptible to foul-
ing than the tubular system, which has a larger flow channel.
This characteristic also makes the tubular membrane much easier
to clean and regenerate than either the spiral-wound or hollow
fiber modules. One manufacturer claims that their helical
tubular module can be physically wiped clean by passing a soft
porous polyurethane plug under pressure through the module.
Application and Performance. In a number of metal processing
plants, the overflow from the first rinse in a countercurrent
setup is directed to a reverse osmosis unit, where it is sepa-
rated into two streams. The concentrated stream contains dragged
out chemicals and is returned to the bath to replace the loss of
solution due to evaporation and dragout. The dilute stream (the
permeate) is routed to the last rinse tank to provide water for
the rinsing operation. The rinse flows from the last tank to the
first tank and the cycle is complete.
The closed-loop system described above may be supplemented by the
addition of a vacuum evaporator after the RO unit in order to
further reduce the volume of reverse osmosis concentrate. The
evaporated vapor can be condensed and returned to the last rinse
tank or sent on for further treatment.
The largest application has been for the recovery of nickel solu-
tions. It has been shown that RO can generally be applied to
299
-------
most acid metal baths with a high degree of performance, provid-
ing that the membrane unit is not overtaxed. The limitations
most critical here are the allowable pH range and maximum operat-
ing pressure for each particular configuration.
Adequate prefiltration is also essential. Only three membrane
types are readily available in commercial RO units, and their
overwhelming use has been for the recovery of various acid metal
baths. For the purpose of calculating performance predictions of
this technology, a rejection ratio of 98 percent is assumed for
dissolved salts, with 95 percent permeate recovery.
Advantages and Limitations. The major advantage of reverse
osmosis for handling process effluents is its ability to
concentrate dilute solutions for recovery of salts and chemicals
with low power requirements. No latent heat of vaporization or
fusion is required for effecting separations; the main energy
requirement is for a high pressure pump. It requires relatively
little floor space for compact, high capacity units, and it
exhibits good recovery and rejection rates for a number of
typical process solutions. A limitation of the reverse osmosis
process for treatment of process effluents is its limited
temperature range for satisfactory operation. For cellulose
acetate systems, the preferred limits are 18<> C to 30° C (65° F
to 85° F); higher temperatures will increase the rate of membrane
hydrolysis and reduce system life, while lower temperatures will
result in decreased fluxes with no damage to the membrane.
Another limitation is inability to handle certain solutions.
Strong oxidizing agents, strongly acidic or basic solutions,
solvents, and other organic compounds can cause dissolution of
the membrane. Poor rejection of some compounds such as borates
and low molecular weight organics is another problem. Fouling of
membranes by slightly soluble components in solution or colloids
has caused failures, and fouling of membranes by feed waters with
high levels of suspended solids can be a problem. A final
limitation is inability to treat or achieve high concentration
with some solutions. Some concentrated solutions may have
initial osmotic pressures which are so high that they either
exceed available operating pressures or are uneconomical to
treat.
Operational Factors. Reliability: Very good reliability is
achieved so long as the proper precautions are taken to minimize
the chances of fouling or degrading the membrane. Sufficient
testing of the waste stream prior to application of an RO system
will provide the information needed to insure a successful
application.
Maintainability: Membrane life is estimated to range from six
months to three years, depending on the use of the system. Down
300
-------
time for flushing or cleaning is on the order of two hours as
often as once each week; a substantial portion of maintenance
time must be spent on cleaning any prefilters installed ahead of
the reverse osmosis unit.
Solid Waste Aspects: In a closed loop system utilizing RO there
is a constant recycle of permeate and a minimal amount of solid
waste. Prefiltration eliminates many solids before they reach
the module and helps keep the buildup to a minimum. These solids
require proper disposal.
Demonstration Status. There are presently at least one hundred
reverse osmosis wastewater applications in a variety of
industries. In addition to these, there are 30 to 40 units being
used to provide pure process water for several industries.
Despite the many types and configurations of membranes, only the
spiral- wound cellulose acetate membrane has had widespread
success in commercial applications. One copper forming plant
currently uses reverse osmosis.
20. Sludge Bed Drying
As a waste treatment procedure, sludge bed drying is employed to
reduce the water content of a variety of sludges to the point
where they are amenable to mechanical collection and removal to a
landfill. These beds usually consist of 15 to 45 cm (6 to 18
in.) of sand over a 30 cm (12 in.) deep gravel drain system made
up of 3 to 6 mm (1/8 to 1/4 in.) graded gravel overlying drain
tiles. Figure VII-32 shows the construction of a drying bed.
Drying beds are usually divided into sectional areas approxi-
mately 7.5 meters (25 ft) wide x 30 to 60 meters (100 to 200 ft)
long. The partitions may be earth embankments, but more often
are made of planks and supporting grooved posts.
To apply liquid sludge to the sand bed, a closed conduit or a
pressure pipeline with valved outlets at each sand bed section is
often employed. Another method of application is by means of an
open channel with appropriately placed side openings which are
controlled by slide gates. With either type of delivery system,
a concrete splash slab should be provided to receive the falling
sludge and prevent erosion of the sand surface.
Where it is necessary to dewater sludge continuously throughout
the year regardless of the weather, sludge beds may be covered
with a fiberglass reinforced plastic or other roof. Covered
drying beds permit a greater volume of sludge drying per year in
most climates because of the protection afforded from rain or
snow and because of more efficient control of temperature.
Depending on the climate, a combination of open and enclosed beds
301
-------
will provide maximum utilization of the sludge bed drying facili-
ties.
Application and Performance. Sludge drying beds are a means of
dewatering sludge from clarifiers and thickeners. They are
widely used both in municipal and industrial treatment facili-
ties.
Dewatering of sludge on sand beds occurs by two mechanisms: fil-
tration of water through the bed and evaporation of water as a
result of radiation and convection. Filtration is generally com-
plete in one to two days and may result in solids concentrations
as high as 15 to 20 percent. The rate of filtration depends on
the drainability of the sludge.
The rate of air drying of sludge is related to temperature, rela-
tive humidity, and air velocity. Evaporation will proceed at a
constant rate to a critical moisture content, then at a falling
rate to an equilibrium moisture content. The average evaporation
rate for a sludge is about 75 percent of that from a free water
surface.
Advantages and Limitations. The main advantage of sludge drying
beds over other types of sludge dewatering is the relatively low
cost of construction, operation, and maintenance.
Its disadvantages are the large area of land required and long
drying times that depend, to a great extent on climate and
weather.
Operational Factors. Reliability: Reliability is high with
favorable climatic conditions, proper bed design, and care to
avoid excessive or unequal sludge application. If climatic con-
ditions in a given area are not favorable for adequate drying, a
cover may be necessary.
Maintainability: Maintenance consists basically of periodic
removal of the dried sludge. Sand removed from the drying bed
with the sludge must be replaced and the sand layer resurfaced.
The resurfacing of sludge beds is the major expense item in
sludge bed maintenance, but there are other areas which may
require attention. Underdrains occasionally become clogged and
have to be cleaned. Valves or sludge gates that control the flow
of sludge to the beds must be kept watertight. Provision for
drainage of lines in winter should be provided to prevent damage
from freezing. The partitions between beds should be tight so
that sludge will not flow from one compartment to another. The
outer walls or banks around the beds should also be watertight.
302
-------
Solid Waste Aspects: The full sludge drying bed must either be
abandoned or the collected solids must be removed to a landfill.
These solids contain whatever metals or other materials were
settled in the clarifier. Metals will be present as hydroxides,
oxides, sulfides, or other salts. They have the potential for
leaching and contaminating ground water, whatever the location of
the semidried solids. Thus the abandoned bed or landfill should
include provision for runoff control and leachate monitoring.
Demonstration Status. Sludge beds have been in common use in
both municipal and industrial facilities for many years. How-
ever, protection of ground water from contamination is not always
adequate.
21. Ultraflltration
Ultrafiltration (UF) is a process which uses semipermeable poly-
meric membranes to separate emulsified or colloidal materials
suspended in a liquid phase by pressurizing the liquid so that it
permeates the membrane. The membrane of an ultrafilter forms a
molecular screen which retains molecular particles based on their
differences in size, shape, and chemical structure. The membrane
permits passage of solvents and lower molecular weight molecules.
At present, an ultrafilter is capable of removing materials with
molecular weights in the range of l,t)00 to 100,000 and particles
of comparable or larger sizes.
In an ultrafiltration process, the feed solution is pumped
through a tubular membrane unit. Water and some low molecular
weight materials pass through the membrane under the applied
pressure of 10 to 100 psig. Emulsified oil droplets and sus-
pended particles are retained, concentrated, and removed continu-
ously. In contrast to ordinary filtration, retained materials
are washed off the membrane filter rather than held by it.
Figures VII-33 and VII-34 represent the ultrafiltration process.
Application and Performance. Ultraflltration has potential
application to copper forming plants for separation of oils and
residual solids from a variety of waste streams. In treating
copper forming wastewater its greatest applicability would be as
a polishing treatment to remove residual precipitated metals
after chemical precipitation and clarification. Successful
commercial use, however, has been primarily for separation of
emulsified oils from wastewater. Over one hundred such units now
operate in the United States, treating emulsified oils from a
variety of industrial processes. Capacities of currently oper-
ating units range from a few hundred gallons a week to 50,000
gallons per day. Concentration of oily emulsions to 60 percent
oil or more are possible. Oil concentrates of 40 percent or more
are generally suitable for incineration, and the permeate can be
303
-------
treated further and in some cases recycled back to the process.
In this way, it is possible to eliminate contractor removal costs
for oil from some oily waste streams.
Table VII-27 indicates ultrafiltration performance (note that UF
is not intended to remove dissolved solids). The removal
percentages shown are typical, but they can be influenced by pH
and other conditions. The high TSS level is unusual for this
technology and ultrafiltration is assumed to reduce the TSS level
by one-third after mixed media filtration.
The permeate or effluent from the ultrafiltration unit is nor-
mally of a quality that can be reused in industrial applications
or discharged directly. The concentrate from the ultrafiltration
unit can be disposed of as any oily or solid waste.
Advantages and Limitations. Ultrafiltration is sometimes an
attractive alternative to chemical treatment because of lower
capital equipment, installation, and operating costs, very high
oil and suspended solids removal, and little required pretreat-
ment. It places a positive barrier between pollutants and
effluent which reduces the possibility of extensive pollutant
discharge due to operator error or upset in settling and skimming
systems. Alkaline values in alkaline cleaning solutions can be
recovered and reused in the process.
A limitation of ultrafiltration for treatment of process
effluents is its narrow temperature range (18° C to 30° C) for
satisfactory operation. Membrane life decreases with higher
temperatures, but flux increases at elevated temperatures.
Therefore, surface area requirements are a function of tempera-
ture and become a tradeoff between initial costs and replacement
costs for the membrane. In addition, ultrafiltration cannot
handle certain solutions. Strong oxidizing agents, solvents, and
other organic compounds can dissolve the membrane. Fouling is
sometimes a problem, although the high velocity of the wastewater
normally creates enough turbulence to keep fouling at a minimum.
Large solids particles can sometimes puncture the membrane and
must be removed by gravity settling or filtration prior to the
ultrafiltration unit.
Operational Factors. Reliability: The reliability of an
ultrafiltration system is dependent on the proper filtration,
settling, or other treatment of incoming waste streams to prevent
damage to the membrane. Careful pilot studies should be done in
each instance to determine necessary pretreatment steps and the
exact membrane type to be used. It is advisable to remove any
free, floating oil prior to ultrafiltration. Although free oil
can be processed, membrane performance may deteriorate.
304
-------
Maintainability; A limited amount of regular maintenance is
required for the pumping system. In addition, membranes must be
periodically changed. Maintenance associated with membrane
plugging can be reduced by selection of a membrane with optimum
physical characteristics and sufficient velocity of the waste
stream. It is often necesary to occasionally pass a detergent
solution through the system to remove an oil and grease film
which accumulates on the membrane. With proper maintenance,
membrane life can be greater than 12 months.
Solid Waste Aspects: Ultrafiltration is used primarily to
recover solids and liquids. It therefore eliminates solid waste
problems when the solids (e.g., paint solids) can be recycled to
the process. Otherwise, the stream containing solids must be
treated by end-of-pipe equipment. In the most probable applica-
tions within the copper forming category, the ultrafilter would
remove concentrated oily wastes which can be recovered for reuse
or used as a fuel.
Demonstration Status. The ultrafiltration process is well
developed and commercially available for treatment of wastewater
or recovery of certain high molecular weight liquid and solid
contaminants. Currently, no plants in the copper forming
category use ultrafiltration. One aluminum forming plant
ultrafilters its spent rolling oils. Ultrafiltration is well
suited for highly concentrated emulsions, for example, rolling
and drawing oils, although it is not suitable for free oil.
22. Vacuum Filtration
In wastewater treatment plants, sludge dewatering by vacuum fil-
tration generally uses cylindrical drum filters. These drums
have a filter medium which may be cloth made of natural or syn-
thetic fibers or a wire-mesh fabric. The drum is suspended above
and dips into a vat of sludge. As the drum rotates slowly, part
of its circumference is subject to an internal vacuum that draws
sludge to the filter medium. Water is drawn through the porous
filter cake thorugh the drum fabric to a discharge port, and the
dewatered sludge, loosened by compressed air, is scraped from the
filter mesh. Because the dewatering of \sludge on vacuum filters
is relatively expensive per kilogram of water removed, the liquid
sludge is frequently thickened prior to processing. A vacuum
filter is shown in Figure VII-35.
Application and Performance. Vacuum filters are frequently used
both in municipal treatment plants and in a wide variety of
industries. They are most commonly used in larger facilities,
which may have a thickener to double the solids content of clari-
fier sludge before vacuum filtering. Often a precoat is used to
inhibit filter blinding.
305
-------
The function of vacuum filtration is to reduce the water content
of sludge, so that the solids content increases from about 5
percent to between 20 and 30 percent, depending on the waste
characteristics.
Advantages and Limitations. Although the initial cost and area
requirement of the vacuum filtration system are higher than those
of a centrifuge, the operating cost is lower, and no special
provisions for sound and vibration protection need be made. The
dewatered sludge from this process is in the form of a moist cake
and can be conveniently handled.
Operational Factors. Reliability: Vacuum filter systems have
proven reliable at many industrial and municipal treatment
facilities. At present, the largest municipal installation is at
the West Southwest wastewater treatment plant of Chicago,
Illinois, where 96 large filters were installed in 1925,
functioned approximately 25 years, and then were replaced with
larger units. Original vacuum filters at Minneapolis-St. Paul,
Minnesota now have over 28 years of continuous service, and
Chicago has some units with similar or greater service life.
Maintainability: Maintenance consists of the cleaning or
replacement of the filter media, drainage grids, drainage piping,
filter pans, and other parts of the equipment. Experience in a
number of vacuum filter plants indicates that maintenance
consumes approximately 5 to 15 percent of the total time. If
carbonate buildup or other problems are unusually severe, mainte-
nance time may be as high as 20 percent. For this reason, it is
desirable to maintain one or more spare units.
If intermittent operation is used, the filter equipment should be
drained and washed each time it is taken out of service. An
allowance for this wash time must be made in filtering schedules.
Solid Waste Aspects: Vacuum filters generate a solid cake which
is usually trucked directly to landfill. All of the metals
extracted from the plant wastewater are concentrated in the
filter cake as hydroxides, oxides, sulfides, or other salts.
Demonstration Status. Vacuum filtration has been widely used for
many years. It is a fully proven, conventional technology for
sludge dewatering. Several copper forming plants report its use.
IN-PLANT CONTROL TECHNIQUES (FLOW REDUCTION)
This section presents a discussion of flow reduction techniques
which are applicable to copper forming plants for the purpose of
reducing the volume of wastewater discharged to treatment. Flow
reduction is a control technique which, in conjunction with the
306
-------
treatment processes previously discussed, can further reduce the
mass of pollutants discharged. The primary flow reduction
techniques which are applicable to copper forming plants are
recycle, alternative rinsing techniques, particularly spray
rinsing and countercurrent rinsing, contract hauling and
reduction of water use.
23. Recycle
Nearly all copper forming plants recycle some process wastewater
streams. The most commonly recycled streams include lubricating
solutions, anneal ing contact cool ing water and solution heat
treatment contact cooling water. In general, some treatment is
required to allow process wastewater recycle in this industry.
At present, the most common treatment practices prior to recycle
in copper forming plants are suspended solids removal, oil
skimming, and cooling. Wastewater is most often returned to the
process operation from which it originated, but may also be used
in other operations.
Recycle is highly effective in reducing pollutant discharges,
often eliminating a continuous discharge completely. Periodic
batch dumps of recycled process water are still usually required,
but the volume of wastewater requiring treatment is greatly
reduced and often is contract hauled. Recycle often reduces
requirements for process materials.
Where recycle is presently practiced, the rate of recycle varies
from approximately 30 to 100 percent. Many copper forming plants
currently achieve zero discharge of some waste streams through
natural evaporation or land application; however, these options
are not available to many plants in the industry. The Agency
recognizes that discharge of wastewater from particular sources
may not be avoided. This is discussed in greater detail in the
context of specific sources.
Cold Rolling, Hot Rolling and Drawing Lubricants. Lubricants
used in cold rolling and drawing are commonly recirculated to
such an extent that contract removal of the total discharge is
practical. Factors which limit the extent of recirculation
include heat removal, degradation of lubricants which results in
staining of the product, or build-up of dissolved or suspended
solids. Some of these limitations may often be overcome by the
application of more advanced treatment techniques than those
presently in common use, as discussed below.
The use of water soluble oil and emulsified oil lubricants in
cold rolling processes makes it easier to recirculate lubricants
than in cases where non-emulsified oil—water mixtures are in
use. In addition, most drawing operations use emulsified lubri-
307
-------
cants. Emulsified lubricants are commonly used repeatedly and
dumped when contamination forces replacement of the solution.
This type of technology uses much less process water and oil on a
yearly basis than most processes which have continuous oil—water
mixture applications; therefore, both process material costs and
treatment or disposal costs can be reduced.
The most common problems encountered in the use of soluble oil
lubricants are the accumulation of heavy metals (especially
copper) and other suspended solids, and the degradation of the
emulsion due to heat and stress. Several methods are used to
prolong the life of the solutions, resulting in even lower end-
of-pipe treatment and disposal costs. Most recirculating
lubricant systems have a storage tank from which the lubricant is
drawn and to which it is returned following application to the
process material. This storage tank serves the dual purpose of
allowing solids to settle and the lubricant to cool prior to
recycle. Some of these tanks are baffled to enhance settling.
In some copper and copper alloy plants, paddle type devices
traveling on a conveyorized belt scrape out solids which have
accumulated on the bottom of lubricant recirculation tanks. This
helps minimize the contamination of the lubricant by avoiding the
build-up of solids on the bottom of the tank. The sludge removed
is often rich enough in copper fines to be sent out for reclama-
tion. Cartridge and membrane filtration is also known to remove
solids from lubricant streams. These filters must be cleaned or
replaced as they become clogged with solids.
Annealing Contact Cooling Water. Annealing quenches using only
water are commonly recycled. Treatment of annealing quench water
prior to recycle is typically limited to settling and heat
removal; however, many sites reported recycle with no prior
treatment.
Because annealing quench operations are characteristically
intermittent, retention and equalization tanks are generally
required for recycle. These tanks can also serve as a settling
basin for removal of suspended solids. Sufficient cooling and
temperature equalization may occur so that a significant portion
of the quench water can be recycled without addition of non-
contact cooling water or the use of a cooling tower.
Total recycle may be prohibited by the presence of dissolved
solids for plants which can not take advantage of natural evap-
oration or land application. Dissolved solids (e.g., sulfates
and chlorides) entering a totally recycled waste stream may
precipitate, forming scale if the solubility limits of the
dissolved solids are exceeded. A bleed stream may be necessary
to prevent maintenance problems (pipe plugging or scaling, etc.)
that would be created by the precipitation of dissolved solids.
308
-------
Hardware necessary for recycle is highly site-specific.
Recycling through cooling towers is the most common practice.
Basic items include the cooling tower, pumps and piping. Addi-
tional materials are necessary if water treatment occurs before
the water is recycled. Chemicals may be necessary to control
scale buildup, slime, and corrosion problems, especially with
recycled cooling water. Maintenance and energy use are limited
to that required by the pumps, and solid waste generation is
dependent on the type of treatment system in place. A typical
flow diagram for a system using a cooling tower to recycle water
is shown in Figure VII-36.
Solution Heat Treatment Contact Cooling Water. Water quenches
(solution heat treatment) are widely used in copper forming
plants following hot deformation processes to rapidly reduce
product temperatures in order to limit surface oxidation and
allow safe handling of the material. The quench water becomes
contaminated with metals, suspended solids, and lubricants, but
the primary effect of this use is elevation of the water
temperature. Because only minor chemical changes are produced in
the quench solutions, extensive recycle and reuse is possible
without deleterious effects on production.
In general, quench water associated with solution heat treatment
produces relatively large volumes of water which contain low
concentrations of pollutants. As a result, treatment effective-
ness is somewhat limited unless in-process control techniques are
employed. Recycle and reuse of the quench water and a reduction
of water use can reduce the volume of effluent requiring treat-
ment and increase pollutant concentrations to more treatable
levels.
24. Alternative Rinsing Techniques
Reduction in the amount of water used and discharged in copper
and copper alloy manufacturing can be realized through the
installation and use of efficient rinsing techniques. The tech-
niques discussed are alternatives to stagnant rinsing. These
techniques can result in water cost savings, reduced waste treat-
ment chemical costs and improved waste treatment efficiency. The
design of rinse systems for minimum water use depends on the max-
imum level of contamination allowed to remain on the workpiece
(without reducing product quality) as well as on the efficiency
or effectiveness of each rinse stream.
Rinsing is used after pickling and alkaline cleaning baths to
dilute the concentration of contaminants adhering to the surface
of a workpiece to an acceptable level before the workpiece passes
on to the next process step. The amount of water required to
dilute the bath solution depends on the quantity of chemical
309
-------
drag-in from the upstream bath tank, the allowable concentration
of chemicals in the rinse water, and the contacting efficiency
between the workpiece and the water.
25. Countercurrent Cascade Rinsing
Process variations such as countercurrent cascade rinsing may
cause a decrease in process water use. This technique reduces
water use by countercurrent multiple stage rinsing of the copper
products. Clean rinse water first contacts the copper in the
last stage. The water, somewhat more contaminated, is routed
stage by stage up the rinsing line. After use in the first rinse
stage, the contaminated water is discharged to treatment.
As an example, Figure VII-37 illustrates three rinsing opera-
tions, each designed to remove the residual acid in the water on
the surface of a workpiece. In Figure VII-37a the piece is
dipped into one tank with continuously flowing water. In this
case, the acid on the surface of the workpiece is essentially
diluted to the required level. In Figure VII-37b, the first
step towards countercurrent operation is taken with the addition
of a second tank. The workpiece is now moving in a direction
opposite to the rinse water. The piece is rinsed with fresh
makeup water prior to moving down the assembly line. However,
the fresh water from this final rinse tank is directed to a
second tank, where it meets the incoming, more-contaminated
workpiece. Fresh makeup water is used to give a final rinse to
the article before it moves out of the rinsing section, but the
slightly contaminated water is reused to clean the article just
coming into the rinsing section. By increasing the number of
stages, as shown in Figure VII-37C, further water reduction can
be achieved. Theoretically, the amount of water required is the
amount of acid being removed by single-stage requirements divided
by the highest tolerable concentration in the outgoing
r insewater. Th is theoret i cal reduct ion of water by a
countercurrent multistage operation is shown in the curve graph
in Figure VII-38. The actual flow reduction obtained is a
function of the dragout and the type of contact occurring in the
tanks. If reasonably good contact is maintained major reductions
in water use are possible.
Significant flow reductions can be achieved by the addition of
only one additional stage in the rinsing operation, as discussed
above. As shown in Figure VII-38 the largest reductions are made
by adding the first few stages. Additional rinsing stages cost
additional money. The actual number of stages added depends on
site-specific layout and operating conditions. With higher costs
for water and waste treatment, more stages might be economical.
With very low water costs, fewer stages would be economical. In
considering retrofit applications, the space available for
310
-------
additional tanks is also important. Many other factors will
affect the economics of countercurrent cascade rinsing; an
evaluation must be done for each individual plant.
Rinse water requirements and the benefits of countercurrent
cascade rinsing may be influenced by the volume of solution drag-
out carried into each rinse stage by the material being rinsed,
by the number of rinse stages used, by the initial concentrations
of impurities being removed, and by the final product cleanliness
required. The influence of these factors is expressed in the
rinsing equation which may be stated simply as:
Vr * Co Vn x VD
Cf
Vr is the flow through each rinse stage.
Co is the concentration of the contaminant(s) in the initial
process bath.
Cf is the concentration of the contaminant(s) in the final
rinse to give acceptable product cleanliness.
n is the number of rinse stages employed.
VD is the dragout carried into each rinse stage, expressed
as a flow.
For a multi-stage rinse, the total volume of rinse wastewater is
equal to n times Vr while for a countercurrent rinse the total
volume of wastewater discharge equals Vr. Drag-out is solution
which remains on the surface of material being rinsed when it is
removed from process baths or rinses.
In the copper forming category, countercurrent cascade rinsing
can be applied to pickling and alkaline cleaning rinsing opera-
tions. To calculate the benefits of countercurrent rinsing for
copper forming, it can be assumed that a two-stage countercurrent
cascade rinse is installed after pickling. The mass of copper in
one square meter of sheet that is 6 mm (0.006 m) in thickness can
be calculated using the density of copper, 8.90 kkg/n* (556
Ibs/cu ft), as follows:
- (0.006 m) x (8.90 kkg/m*) - 0.053 kkg/m* of sheet.
Using the mean pickling rinse water use from Table V-12 (p. 103),
Vr can then be calculated as follows:
Vr « 0.053kka x 4,000 1
w* "Tlcg
- 213.6 1/m* of sheet
311
-------
If the film on a piece of copper sheet is 0.015 mm (0.6 mil)
thick, (equivalent to the film on a well-drained vertical
surface) then the volume of process solution, VD, carried into
the rinse tank on one square meter of sheet will be:
VD = (0.015 mm) X
]__ m/mm x (1000 1/m*)
1000
= 0.015 l/mz of sheet
Let r - Co, then r 1/n = Vr
Cf VD
For single stage rinsing n - 1
Therefore r =Vr
VD
and r =213.7= 14,240
0.015
For a 2-stage countercurrent cascade rinse to obtain the same r,
that is the same product cleanliness,
Vr = rh and:
VD
119.3
VD
But VD - 0.015
of sheet.
Therefore for 2-stage countercurrent cascade rinsing Vr is:
Vr = 119.3 x 0.015 * 1.79 1/m* of sheet.
In this example, two-stage countercurrent cascade rinsing
achieved 99.2 percent reduction in the water used. The actual
numbers may vary depending on efficiency of squeegees or air
knives, and the rinse ratio desired.
Countercurrent cascade rinsing has been widely used as a flow
reduction technique in the metal finishing industry. Counter-
current cascade rinsing is currently practiced at four copper
forming plants. In aluminum conversion coating lines that are
subject to the coil coating limitations, countercurrent cascade
rinsing is currently used in order to reduce costs of wastewater
treatment systems (through smaller systems) for direct dis-
chargers and to reduce sewer costs for indirect dischargers.
312
-------
26. Spray Rinsing
Spray rinsing is another method used to dilute the concentration
of contaminants adhering to the surface of a workpiece. The
basis of this approach is to spray water onto the surface of the
workpiece as opposed to submerging it into a tank. The amount of
water contacting the workpiece is minimized as is the amount of
water discharged. The water use and discharge rates can be
further reduced through recirculation of the rinse water. Copper
forming plants practicing spray rinsing discharge typically 60
percent less water than those plants using only stagnant rinses.
The equipment required for spray rinsing includes piping, spray
nozzles, a pump, a holding tank, and a collection basin. The
holding tank may serve as the collection basin to collect the
rinse water prior to recirculation as a method of space economi-
zation.
27. Contract Hauling
Contract hauling refers to the industry practice of contracting a
firm to collect and transport wastes for off-site disposal; This
practice is particularly applicable to low-volume, high concen-
tration waste streams. Examples of such waste streams in the
copper forming industry are pickling baths, drawing lubricants,
cold rolling lubricants, annealing oil and extrusion press solu-
tion heat treatment.
28. Reduction of Water Use
The reduction of process water use has been found to be an
effective approach to reducing treatment costs and pollutant dis-
charges at many copper forming plants. In most cases, substan-
tial reduction may be achieved by simple actions involving little
or no cost. It is often found that satisfactory operation may be
achieved with much smaller rinse or contact cooling water flows
than have generally been used. Many of the copper forming plants
visited reported recent significant reductions in process water
use and discharge.
Many production units in copper forming plants -operate intermit-
tently or at widely varying production rates. The practice of
shutting off process water streams during periods when the unit
is inoperative and of adjusting flow rates during periods of low
activity can prevent much unnecessary dilution of wastes and
reduce the volume of water to be treated and discharged. Water
may be shut off and adjusted manually or through automatically
controlled valves. Manual adjustment involves minimal capital
cost and can be just as reliable in actual practice. Automatic
shut off valves are used in some copper forming operations to
313
-------
turn off water flows when production units are inactive. Auto-
matic adjustment of flow rates according to production levels
requires more sophisticated control systems incorporating temper-
ature or conductivity sensors. Further reduction in water use
may be made possible by changes in production techniques and
equipment.
The potential for reducing the water use at many copper forming
facilities is evident in the water use and discharge data pre-
sented in Section V of this report. While it may be argued that
variations in water flow per unit of production are the necessary
result of variations in process conditions, on-site observations
indicate that they are more frequently the result of imprecise
control of water use. This is confirmed by analysis data from
pickling and alkaline cleaning rinses which show a very wide
range of the concentrations of materals removed from product
surfaces, and by on-site temperature observations in contact
cooling streams.
Reduction of water use in quenches may also significantly reduce
discharge volumes. Design of spray quenches to ensure that a
high percentage of the water contacts the product and adjustments
of make-up water flow rates on quench baths and recirculating
spray quench systems to the minimum practical value can
significantly reduce effluent volumes.
Pollutant discharges from pickling and alkaline cleaning may also
be controlled through the use of drag-out reduction technologies.
The volume of water used and discharged from rinsing operations
may be substantially reduced without adversely affecting the
surface condition of the product processed. Available tech-
.nologies to achieve these reductions include techniques which
limit the amount of material to be removed from product surfaces
by rinsing.
On automatic lines which continuously process strip through alka-
line cleaning and pickling operations, measures are normally
taken to reduce the amount of process bath solutions which are
dragged out with the product into subsequent rinses. The most
commonly used means of accomplishing this are through the use of
squeegee rolls and air knives. Both mechanisms are found at the
point at which the strip exits from the process bath. Squeegee
rolls, one situated above the strip and another below, return
process solutions as they apply pressure to both sides of the
continuously moving strip. Air knives continuously force a jet
of air across the width of each side of the strip, forcing solu-
tions to remain in the process tank or chamber. These methods
are also used to reduce drag-out from soap and other lubricant
tanks which are often found as a final step in automatic strip
lines.
314
-------
Heating the tank containing the process bath can also help reduce
drag-out of process solutions in two ways: by decreasing the
viscosity and the surface tension of the solution. A lower
viscosity allows the liquid to flow more rapidly and therefore
drain at a faster rate from the product following application in
a process bath, thereby reducing the amount of process solution
which dragged out into suceeding rinses. Likewise, a higher
temperature will result in lower surface tension in the solution.
The amount of work required to overcome the adhesive force
between a liquid film and a solid surface is a function of the
surface tension of the liquid and the contact angle. Lowering
the surface tension reduces the amount of work required to remove
the liquid and reduces the edge effect (the bead of liquid
adhering to the edges of a product).
Operator performance can have a substantial effect on the amount
of drag-out which results from manual dip tank processes. Spe-
cifically, proper draining time and techniques can reduce the
amount of process solution dragged out into rinses. After dip-
ping the material into the process tank, drag-out can be reduced
significantly by simply suspending the product above the process
tank while solution drains off. Fifteen to 20 seconds generally
seems sufficient to accomplish this. When processing tubing,
especially, lowering one end of the load during this drain time
allows solution to run off from inside the tubes.
All of the water use reduction techniques discussed in this
section may be used at copper forming plants to achieve the
average production normalized flows at plants which presently
discharge excessive amounts of wastewater to treatment.
CURRENT INDUSTRY PRACTICE
Out of 18 plants which reported a discharge of annealing water,
six currently practice cooling and recycle. Reported recycle
rates range from 50 to 98 percent. Of 24 plants which reported
the use of water for solution heat treatment, eight plants also
reported the use of recycle with recycle rates from 85 to 100
percent.
A large number of plants which practice drawing, cold rolling or
annealing with oil reported the practice of extensive recycling
of the lubricant streams with treatment or contract hauling of
the small amount of spent lubricant which is periodically
discharged.
The use of alternate rinsing techniques in pickling operations
was reported by approximately one-third of the 42 plants which
have pickling operations. The most frequently reported alternate
rinsing technique for pickling is spray rinsing. Spray rinsing
315
-------
of pickling rinse water is practiced in 16 copper forming plants.
Countercurrent cascade rinsing and multi-stage rinsing were also
reported. Countercurrent cascade rinsing is currently practiced
by four plants in the copper forming industry.
316
-------
Table VII-1
pH CONTROL, EFFECT ON METALS REMOVAL
Day 1 Day 2 Day 3
Out In Out In Out
pH Range 2.4-3.4 8.5-8.7 1.0-3.0 5.0-6.0 2.0-5.0 6.5-8.1
(mg/1)
TSS 39 8 16 19 16 7
Copper 312 0.22 120 5.12 107 0.66
Zinc 250 0.31 32.5 25.0 43.8 0.66
317
-------
Table VII-2
EFFECTIVENESS OF SODIUM HYDROXIDE FOR METALS REMOVAL
Day 1
pH Range
(mg/1)
Cr
Cu
Fe
Pb
Mn
Ni
Zn
TSS
In
2.1-2.9
0.097
0.063
9.24
1.0
0.11
0.077
0.054
Out
9.0-9.3
0.0
0.018
0.76
0.11
0.06
0.011
0.0
13
Day 2
In
2.0-2.4
0.057
0.078
15.5
1.36
0.12
0.036
0.12
Out
8.7-9.1
0.005
0.014
0.92
0.13
0.044
0.009
0.0
11
Day 3
In
2.0-2.4
0.068
0.053
9.41
1.45
0.11
0.069
0.19
Out
8.6-9.1
0.005
0.019
0.95
0.11
0.044
0.011
0.037
11
318
-------
Table VII-3
EFFECTIVENESS OF LIME AND SODIUM HYDROXIDE
FOR METALS REMOVAL
Day 1 Day 2 Day 3
In Out In Out In Out
pH Range
(mg/1)
Al
Co
Cu
Fe
Mn
Ni
Se
Ti
Zn
TSS 4,
9.2-9.6
37.3
3.92
0.65
137
175
6.86
28.6
143
18.5
390
8.3-9.8
0.35
0.0
0.003
0.49
0.12
0.0
0.0
0.0
0.027
9 3
9.2
38.1
4.65
0.63
110
205
5.84
30.2
125
16.2
,595
7.6-8.1
0.35
0.0
0.003
0.57
0.012
0.0
0.0
0.0
0.044
13
9.6
29.9
4.37
0.72
208
245
5.63
27.4
115
17.0
2,805
7.8-8.2
0.35
0.0
0.003
0.58
0.12
0.0
0.0
0.0
0.01
13
319
-------
Table VII-4
THEORETICAL SOLUBILITIES OF HYDROXIDES AND SULFIDES
OF SELECTED METALS IN PURE WATER
Metal
Cadmium (Cd++)
Chromium (Cr+++)
Cobalt (Co++)
Copper (Cu++)
Iron (Fe++)
Lead (Pb++)
Manganes e (Mn++)
Mercury (Hg++)
Nickel (Ni++)
Silver (Ag+)
Tin (Sn++)
Zinc (Zn++)
Solubility of Metal Ion, mg/1
As Hydroxide
2.3 x 10'5
8.4 x 10'4
2.2 x 10'1
2.2 x TO'2
8.9 x 10'1
2.1
1.2
3.9 x 10-4
6.9 x 10-3
13.3
1.1 x 10-4
1.1
As Carbonate
1.0 x 10~4
7.0 x TO'3
3.9 x 10-2
1.9 x 10-1
2.1 x 10'1
7.0 x 10-4
As Sulfide
6.7 x 1(H°
No precipitate
1.0 x 10'8
5.8 x 10'18
3.4 x 10-5
3.8 x 10'9
2.1 x TO'3
9.0 x TO'20
6.9 x 10-8
7.4 x 10-12
3.8 x TO'8
2.3 x 10~7
320
-------
m
i
M
H-l
>
0>
rH
-Q
CD
H
CO
•5
W
H
CO
CO
z
o
H-l
H
^J
H
35
a
s
H-l
Q
CO
I
S5
O
H-l
EH
1-1 -^
V4 V4
(U CO
far-l
CJ
3? -
OCO
oi CN
25 03
35
4J
jj
O
C
M
m
o
o
»
V
m
^~
•
^>
*-
*
0)
•U W
^t 4)
.r-t 4J
CO OrH
4) W *iH
fa -U fa
O
. 0) -
_J >~H 4J
O Ot
P-. CO
u
jj
o
c
H-l
^
ON T—
1 O
00
o
\/
00
vO
1 \O
o
• m
m CM
^
o
*
o
V
CO
»
CM
CO
o
1 •
1 O
Cvj
m
i *
1 O
f*»
o
1 O
\/
m
i •
1 ON
CO
4J
C
Ot
a
4J
CO
0)
oo
a
U
(U -H
321
-------
Table VII-6
SULFIDE PRECIPITATION-SEDIMENTATION PERFORMANCE
Parameter Treated Effluent (mg/1)
Cd 0.01
Cr (Total) 0.05
Cu 0.05
Pb 0.01
Hg 0.03
Ni 0.05
Ag 0.05
Zn 0.01
322
-------
Table VII-7
FERRITE CO-PRECIPITATION PERFORMANCE
Metal Influent (mg/1) Effluent (mg/1)
Mercury 7.4 0.001
Cadmium 240 0.008
Copper 10 0.010
Zinc 18 0.016
Chromium 10 <0.010
Manganese 12 0.007
Nickel 1,000 0.200
Iron 600 0.06
Bismuth 240 0.100
Lead 475 0.010
323
-------
Plant ID
06097
13924
18538
30172
36048
Mean
Table VII-8
MULTIMEDIA FILTER PERFORMANCE
TSS Effluent Concentration, mg/1
0.0, 0.0, 0.5
1.8, 2.2, 5.6, 4.0, 4.0, 3.0, 2.2, 2.8
3.0, 2.0, 5.6, 3.6, 2.4, 3.4
1.0
1.4, 7.0, 1.0
2.1 , 2.6, 1.5
2.61
324
-------
CT»
1
r-(
r-l
>•
0)
r-l
,Q
cd
H
CO
S
M
H
CO
r*4
V2
O
z
1—4
^
§•*
H
W
CO
Q
M
H
u
w
•J
Cd
CO
fa
O
M
O
Z
l-l
Oi
s
z
o
H
EC
H
Z
M
O
Z
o
o
CO
Q
O
CO
Q
W
Q
Z
W
CM
CO
3
CO
u
o
en
Q
C
W
3
O
CN
^.
cd
a
c
*""*
4J
^
O
I—
^
cd
Q
C
1-1
O
CM
CN
O
m
ao
CM
CN
o
o
I O
I *—
CM
CM
en en
i— CN
m
o
00
*.
CN
CO
oo
en
m
CM
vo
m
o\ <—
m *-
en
en
ao CM
O
O
oo
CN
CM m
ao &i
*- CN
OH
w
CM
00
c a>
^l O
•P 0)
1) Q
CO
c
o
o
00
cd
l-l
CD 00
•H C
f4 i—\ CO
-J WT3
cd w c
r-l
-------
Table VII-10
SKIMMING PERFORMANCE
Oil & Grease (mg/1)
Plant Skimmer Type In put
06058 API 224,669 17.9
06058 Belt 19.4 8.3
326
-------
Table VII-11
SAMPLING DATA FROM COPPER FORMING PLANTS WHICH PRACTICE
OIL SKIMMING AND ACHIEVE EFFLUENT OIL AND GREASE
CONCENTRATIONS OF 20 mg/1 OR LESS
Influent Effluent
Concentration (mg/1) Concentration (mg/1)
Plant Oil and Grease TTO Oil and Grease TTO
06058 53,800 166.2 16.3 0.02
395,538 0.51 13.3 0.31
^7432 7,070 10.39 15 0.04
1,004 0.11 5 0.01
327
-------
Table VII-12
CHEMICAL EMULSION BREAKING EFFICIENCIES
Concentration (mg/1)
Parameter Influent Effluent Reference
O&G 6,060 98 Sampling data*
TSS 2,612 46
O&G 13,000 277 Sampling data+
18,400
21,300 189
TSS 540 121
680 59
1,060 140
O&G 2,300 52 Sampling data**
12,500 27
13,800 18
TSS 1,650 187
2,200 153
3,470 63
O&G 7,200 80 Katnick and Pavilcius, 1978++
*0il and grease and total suspended solids were taken as grab
samples before and after batch emulsion breaking treatment which
used alum and polymer on emulsified rolling oil wastewater.
+0il and grease (grab) and total suspended solids (grab) samples
were taken on three consecutive days from emulsified rolling
oil wastewater. A commercial demulsifier was used in this batch
treatment.
**0il and grease (grab) and total suspended solids (composite)
samples were taken on three consecutive days from emulsified
rolling oil wastewater. A commercial demulsifier (polymer)
was used in this batch treatment.
++This result is from a full-scale batch chemical treatment system
for emulsified oils from a steel rolling mill.
328
-------
Table VII-13
COMBINED METALS DATA EFFLUENT CONCENTRATIONS (mg/1)
Cd
Cr
Cu
Pb
Ni
Zn
Fe
Mn
TSS
Mean
0.079
0.084
0.58
0.12
0.74
0.33
0.41
0.21
12.0
One -Day
Max.
0.34
0.44
1.90
0.15
1.92
1.46
1.23
0.43
41.0
10 -Day Avg.
Max.
0.15
0.18
1.00
0.13
1.27
0.61
0.63
0.34
20.0
30 -Day Avg.
Max.
0.13
0.12
0.73
0.12
1 .00
0.45
0.51
0.27
15.5
329
-------
Table VII-14
L&S PERFORMANCE
ADDITIONAL POLLUTANTS
Pollutant Average Performance (mg/I)
Sb 0.70
As 0.51
Be 0.30
Hg 0.06
Se 0.30
Ag 0.10
Th 0.50
Al 2.24
Co 0.05
F 14.5
330
-------
Table VII-15
COMBINED METALS DATA SET - UNTREATED WASTEWATER
Pollutant Mln. Cone, (mg/1) Max. Cone, (mg/1)
Cd <0.1 3.83
Cr <0.1 90.0
Cu <0.1 89.0
Pb <0.1 29.2
Ni <0.1 11.6
Zn <0.1 337.
Fe <0.1 208.0
Mn <0.1 245.0
TSS 4.6 4,390
331
-------
Table VII-16
MAXIMUM POLLUTANT LEVEL IN UNTREATED WASTEWATER
ADDITIONAL POLLUTANTS
(mg/D
Pollutant As & Se
As 4.2
Be
Cd <0.1
Cr 0.18
Cu 33.2
Pb 6.5
Ni
Ag
Zn 3.62
F
Fe
O&G 16.9
TSS 352
Be
--
10.24
--
8.60
1.24
0.35
--
—
0.12
--
646
_-
796
Ag .
--
—
<0.1
0.23
110.5
11.4
100
4.7
1 ,512
--
--
16
587.8
F
--
--
<0.1
22.8
2.2
5.35
0.69
--
<0.1
760
--
2.8
5.6
332
-------
•
CM >
0)
+ Q
C.
•
Cd *O
o co co m
t— O -* ON 00
O O O O O
r**
M
>
QJ:
c
as
CO
4J
C
•H
O
CM
O
Z
CO
Vi
01
4-)
0)
e
cd
V4
cd
CM
V4
0)
-U
ca
0)
4-1
CO
cd
•o
(U
4J
CO
0)
J-l
E-t
I
^^
f^
Q\
_
)_,
O
to
ON vO
CM O COON
OOi-O
O O OO
+ 1+1+1+1
m ON
O O CM *~
OO OO
CO CO >-i
U O Z t-3 to E-t
1
oo
f-^
ON
<-
t.
O
to
O
O T— -
-------
00
I
H-1
tu
eO
H
a!
O
fa
CO
•*—*
o
H cd
CM
H
H
Cd
CO
I
O
M
a!
Cu
•
CM >
0)
+ a
C~
•
2: co
»
-^ 1 ^D
Q
C
cd •
a> *o
2* jj
CO
,-H
0£
@
v_/
0)
Ofl
cd
cn
C
•i-i
O
CM
*
O
Z
CO
jj
0)
4J
a;
e
a*
cd
a,
^4
0)
rt
01
U
W
1
'S
4J
cd
0)
^j
H
|
^y\
p^
ty\
o
CM (-•- ON 30 O
CM O ^O t— i—
O OO O i—
in ^- >3" >d" oo
r*** CM co *>O c^
O OCM O CO
O OO O 0
+ 1+I+I+I+I
00 ^3" ON ^ co
^o CM •— m o
O O CM O CO
O O O 0 O
O CM ON \D O O
O O ^~ O CM t—
i i i i r t
^_^_ ^_o
o o o o o o
o ooo o t-
J_J
in >*o in m ^ CM — ^d" cd
-4" *d" -^ CO -3" ^
T1
*J
*
O O O 0<-
m *— i— ^ o
o o CM o m
o o oo o
+ I+I + I+I+I
oo T— T—
o o *— o co
till!
oo oo o
o o oo o
oo o r* co r-
OO ON OO I — OO
CM CM CM CM CM
^- ^ r— ^ T—
J-i £3 *i-t C ^
O U Z C"0 fa
o r-. co
O^ i — CO ^
m o co CM
CM
LO P1*- O\ O^
T— CM OO CO ON
ON o -J" co in ^o
•&
1 1 1 1 ! 1
o ON ,— m co
oo o ^o co »—
CM o <— CM co r**
CO CO CO CM CO CM
CO
J-I ^ -H ^ CU CO
U U Z c<] fa H
cu
4J
CO
CO
cd
a!
334
-------
ON
i—
1
1— 1
M
^
OJ
,_|
XI
CO
H
W
U
Q
C
cO •
OJ 'O
S 4-*
CO
,— 1
of
s
^
OJ
o£
C
Of!
CO
4J
C
•H
O
IX,
•
o
2
CO
S-i
OJ
4J
(U
e
cQ
l-i
cO
PM
r*« CM -^ \o
-^ m en . o m
»— m en en ON
• * • • •
o o en *— '*
CM
ON T— en *— en
* oo *D
•
CO
(U
r-t
CO
en en en
00 O
M-l
O
c
CO
"O
OJ
s
09
CO *H
CO !U
H (X 0)
2
r-l
CO
fX
-X
335
-------
O
CM
a
4J -H
0) 10 JJ
T3 OJ (0
m fa
£
O CO
.
21
CM CM
i
C >i
• - Jj 0) flJ
*W QiJJ H (3
CO
?
o g c >«
fa r^ ® ^ J5 ^
3g« HS<
l^1
JD •
H ffi >«X
BJ
C >i
£jncM
OOO
oo in m
OOO
CO OS CM
O\ CO 00
r— r— O
••a* CO CM
OOO
r- CO ^"
r-^ O O
00 \O i—
CM oo in
r- O O
00 O CM
CMCM^-
O r- O
OOO
•Q Q Q?
CO rtj QQ
2^^
r— OO OO
OOO
OOO
00 i— i—
r- OS OS
OOO
OOO
O CM CM
OOO
r- oo in
OOO
OOO
GO O OS
OOO
00 lO r**1*
f^ f— • ^^
OOO
o r- oo
O O r-i
IBR
OOO
CO CM CO
OOO
in oo o
.— r-O
OOr-
SSS
OOr-
OS ^*
r- oo co
o o in
OOO
51* 3
uu
CO OS O
r- ,— CM
O
o
00
o
o
C
o
o
o
o I—
o o
oo en
O •—
o o
O CO
o o
o c
o o
r- \O
i— r-
o o
CM O
r- CM
0 O
S3
O O
s-
o o
5&
CM CM
OS
O
o
in
in
in
o
o
S
o
m
o
o
D
O
O
o
in
o
ID
m
o
o
o
o
o
o
in
CM
o
o
o
s
N
00 00
0 0
o o
OS OS
0 O
O 0
r- r-
CM CM
O 0
in in
0 O
o o
os m o
CM CO r-
OOO
r- p- CM
co m •—
OOO
in CM os
in GO CM
OOO
CM o r-
CM CM O
OOO
O OS VO
O ^ r-
r- O O
r*- in r-
CM in r-
r- O O
CM CO r-
OS CM ^*
r- r- O
xj1 ^3 o
r- m •—
OOO
sx*
^& LO ^0
CM CM CM
O
O
GO
r—
O
o
o
o
o
o
in r-
in co
o o
in ^
o* o"
O CM
^* o
r- r-
^f CO
CO CM
O O
r- in
00 ^1*
0 0
^t ,_
00 *
o o vo
r— Os fO
VO CM CO
O O *O
O 00
OJ ^D ^^*
^** ^^ ^D
r- « GO
^C i— O
C3 ^^ ^*
IS"
0 O
0 O
r- r-
0 O
O CM
r- r-
O 0
o in
r- r-
CM
o in
p in
o m
CM OS
r- r-
o o
O r-
CM •*
O
CM
r"
§g
336
-------
Table VII-21
TKEATABILXTY RATIWG OF PRIORITY PCLLDTAHTS
UTILIZING CARBON ADSORPTION
Priority Pollutant
1. acenepnthene H
2. acrolein L
3. aerylonitrile L
4. benzene H
5. benzidlne B
6. carbon tetrachloride . H
{tetrachloroaethane)
7. efalorobenzene B
8. 1,2,3-trichlorobenaene B
9. hexachlorobenzene B
10. 1,2-dichloroethane H
11. 1,1,1-trichloroethmne H
12. hexechloroethane H
13. l,l-dichloroeth*ne M
14. 1,1,2-trichloroethane H
15. 1,1,2,2-tetrachlorethan* B
16. chloroethaae L
17. bia(ehloroMthyl) ether
18. bis(2-chloroethyl) ether H
19. 2-chloroethylvinyl ether L
(mixed)
20. 2-chlQronaphthalene B
21. 2,4,6-triehlorophenol B
22. parachlorooeta cre«ol B
23. chloroform (trichloroaethane) L
24. 2-chlorophenol H
25. 1,2-dichlorobenxene H
26. 1,3-diehlorobenzene a
27. 1,4-dicnlorobenzene B
28. 3,3'-dichlorobenxidin100 ag/g carbon at C. < 1.0 mg/1
Category M (moderate removal)
adsorbs at levels £ 100 rag/g carbon at C, - 10 mg/1
adsorbs at levels £ 100 mg/g carbon at Cf < 1.0 mg/1
Category > (low removal)
adsorbs at levels < 100 mg/g carbon at C, " 10 mg/1
adsorbs at levels < 10 mg/g carbon at Cf < 1.0 mg/1
C, • final concentrations of priority pollutant at equilibrium
337
-------
TABCZ VII - 22
CLASSES OF ORGANIC COMPOUNDS ADSORBED CN CARBCN
Organic Chemical Class
Arcnatic Hydrocarbons
Polynuclear Aronatics
Chlorinated Aromatics
Phenolics
Chorinated Phenolics
Examples of
Jtolecular Wei^rt Aliphatic and
Branch Chain hydrocarbons
Qilorinated Aliphatic hydrocarbons
*High Molecular Wei^it Aliphatic
Acids and Arcnatic Acids
*High MDlecular Weight Aliphatic
Amines and Aromatic
*High Molecular Wei^it Ketones,
Esters, Ethers and Alcohols
Surfactants
Solubla Organic Dyes
benzene, toluene, xylene
naphthalene, anthracene
biphenyls
chlorobenzene, polychlorinated
bijtoenyls, aldrin, endrin,
toxaphene, COT
phenol, cresol, resorcenol
and polyphenyls
trichlorophenol, pentachloro-
phenol
gasoline, Tcerosine
carbon tetrachloride,
perchloroethylene
tar acids, benzoic acid
aniline, toluene diamine
hydroquinone, polyethylene
glycol
alkyl benzene sulfonates
methylene blue, indigo cannine
* High Molecular Weight includes compcunds in the "arcad range
4 to 20 carton atcms
;r rrcm
338
-------
Table VII-23
ACTIVATED CARBON PERFORMANCE
Mean Pollutant Levels
Type of ug/1
Industry Pollutant Parameter In Out
NFM Fluoranthene 55 13
Foundries N-nitrosodiphenylamine 250 190
NFM Benzo(a)anthracene 13 0.7
NFM Chrysene 160 3.8
NFM Anthracene 43 6.6
NFM Phenanthrene 46 4.6
NFM Pyrene 130 11
339
-------
Table VII-24
ION EXCHANGE PERFORMANCE
(All Values mg/1)
Plant A
Parameter
Al
Cd
Cr+3
Cr+6
Cu
CN
Au
Fe
Pb
Mn
Ni
Ag
S04
Sn
Zn
Prior to
Purifica-
tion
5.6
5.7
3.1
7.1
4.5
9.8
__
7.4
--
4.4
6.2
1 .5
--
1.7
14.8
After
Purifica-
tion
0.20
0.00
0.01
0.01
0.09
0.04
-_
0.01
--
0.00
0.00
0.00
--
0.00
0.40
Plant B
Prior to
Purifica-
tion
43.0
3.40
2.30
1 .70
1 .60
9.10
210.00
1.10
After
Purifica-
tion
0.10
0.09
0.10
0.01
0.01
0.01
2.00
0.10
340
-------
Table VII-25
PEAT ADSORPTION PERFORMANCE
Pollutant
Cr+6
Cu
CN
Pb
Hg
Ni
Ag
Sb
Zn
Influent (mg/1)
35,000
250
36.0
20.0
1.0
2.5
1.0
2.5
1.5
Effluent (mg/l)
0.04
0.24
0.7
0.025
0.02
0.07
0.05
0.9
0.25
341
-------
CM
I
H
Z
W
Ct,
H 00
CO e
>*
CO C
f-l
z
O co
(0
U
CQ
S
Ed
s
01 e
V4 CU
4-)
CM 3
CM O
O
r—
CO
4J
C
CO
r-l
pn c
1-1
-u
\o 3
^O ^-.-^
o
2
4-)
C
cfl
<— <
ft* C
hH
CO
V
in CM
o o —
o o o
^ Z *H
CU U Z
o
t- O
• •
o »-
m
O 0
• •
O 00
o
0 0
• •
in en
*~
-^
O i-
O 0
^
o
•
CM CM
m
vO
i— 1
O
CO
C CO
csj H
342
-------
Table VII-27
ULTRAFILTRATION PERFORMANCE
Parameter Feed (mg/1) Permeate (mg/1)
Oil (freon 95 22*
extractable) 1,540 52*
1,230 4
COD 8,920 148
TSS 791 19*
1,262 26*
5,676 13*
1,380 13
Total Solids 2,900 296
*From samples at aluminum forming Plant B
343
-------
c
u
.J
.1
o
c
Z
o
K —
Id u
C I a
i 2 x
< I o
J 0 K
O C O
o s
r
I
i
i
i
i
i
i
t_
n
u
i
•
i
i
h
i
}_M
'-•
_n
k
4J
X
Z
H
Z
o
PRCCIflTAT
X
o
r-t
0
ad
O
B
K
Z
0
u
a.
c
0
r
= 1
• Q
u
c
22
^ U
3 <
D
* <
Z -
3
Z
0
E
Z
i
>-* 2
w C
> i-t
03 U
as
Z
(-4
i
Z
Ed
Z
111 U
J- J
B i
344
-------
to-
J
<
a
u
10'
10"
to"
10-
to"
to-
z
3
ro"
10
10
-10
11
,-12
to*
-13 I ( I I t )
2 3 4 5 » 7 • f IQ 11 \2
9M
Figure VII-2
COMPARATIVE SOLUBILITIES OF METAL HYDROXIDES
AND SULFIDE AS A JUNCTION OF pH
345
-------
4 i*
coo
-------
0.40
SCO A ASH AND
CAUSTIC SODA
t.0
10.3
Figure VII-4
LEAD SOLUBILITY IN THREE ALKALIES
347
-------
EFFLUENT
INFLUENT
,1 ,
(n\ «-Km—
^U' DEPTH
30*40 fa—* ** * • SANO •' • .*.'
.;•*.••; COARSE
r OVERFLOW
/ TROU6H
/ 1
^ #% ^% ^^ ^^ ^T ^
• * * ** C» • '.',"•
• . •. .-. • C •
^ ••* •. . '.-••
•.^' *'• \-. •• i>
» • * • • *
i '*. COARSE*
«
X-««T TO
RPTAJH / — \
SAND (Z)
STRAINEH -\
EFFLUENT
DEPTH-'
i \ iNFLUENT MHficona
1 TOTWMT \ U«£™
UNOERORAiN 1 UNOERORA1N \
DUMBER — * CHAMBER — 1
INFLUENT
(d)
COARSE »EmA-^?^5£^| I
FINER MEDIA — ^siuife 1
FINEST MEDIA— -^£3ttij&^; [
40 ii
1 ? EFFLUENT
COARSE UEDIA'-
FINEH ME3IA— ^
FINEST MEDIA —
UNOERORAU
CHAMBER
__
• • •' ™ 1 W ft * . **
• • * • 1 * • ^ • • *
* * * * *
•
UN \
j| — i
INFLUENT
ANTHRACITE
4;-/-\c'OAu':-.;
• ^ . ' . ."^^
uiJ^:
=2^
L»-
i INFLUENT
---^
^«^^^^^»
-r
. a\*M
f^^^l T
r ^
I ! ^-«ARNET 3ANO
1 \ » EFFLUENT
Figure VII-5
FILTER CONFIGURATIONS
(a) Single-Media Conventional Filter. (d) Dual-Media- Filter.
(b) Single-Media Upflow Filter. (e) Mixed-Media (Triple-
(c) Single-Media Siflow Filter. Media) Filter.
348
-------
CFFLUEN'
INFLUENT
ALUM
WATCH
LEVEL
STORED
• AC X WASH
WATER
w
POLYMER
FILTER
COMPARTMENT
SAN I
MCOIX
^f^^^^f-**^*' -i" ***
u u a a u u
COLLECTION CHAMBER
U U u U U
THKCC WAY VALVE
DRAIN
Figure VTI-6
GRANULAR BED FILTRATION
349
-------
SEDIMENTATION BASIN
INLET ZONE
BAFFLES TO MAINTAIN
QUIESCENT CONDITIONS
INLET L1OUIO
OUTLET ZONE
OUTLET LIQUID
SETTLING PARTICLE
t
SCLT-TYFE SOU OS COLLECTION
MECHANISM
SETTLED PARTICLES COLLECTED
AND PERIODICALLY REMOVED
CIRCULAR CLAR1FIER
SETTLING ZONC.
INLET LIQUID
CIRCULAR BAFFLE
INLET ZONE —-
* • • •
• • A* '.*
^!_- -V.-
ANNULAR OVERFLOW WEIR
• • • "y • •
* • */• UOUIO *
'• WFLOW /
OUTLET LJQU1O
REVOLVING COLLECTION
MECHANISM
I
SETTLING PARTICLES
SETTLED PARTtCUES
COLLECTED AND PERIODICALLY
REMOVES
SLUDGEORAWOFF
Figure VII-7
REPRESENTATIVE TYPES OF SEDIMENTATION
350
-------
UJ
0.
UJ
CO
CO
1
Qti
O
58
o.
Cxi
M as
3
*4
Cb
i
u
M
<
as
C3
crt
351
-------
8
H
cn
cjcn
M Z
zo
can
Ed
CO
OS >
00
H
CJ Z
M Ed
OZ
< Ed
HW
Ed
00 J
H
Ou O
cn
z
O
Cd
oci
352
-------
>
H-
(T
O
I
CO
O
r~4
I
w
>
o
3 93
00 J
s
O
J
b*
353
-------
observations = 2
Numbe
Waste Concent
Cadmium
s?
Ul
z
UJ
>
u
Ul
u.
u.
UJ
z
o
sH
I z
= s =
> 1 =
in 5 i
CC £ Q
3 K <
So"
"- p
<
I-
HYDROXIDE PREC
(I/Bui) uoiiBJiurauoa luanuH paieaii uimuipeo
with a raw waste concentra
1 mg/l were not included in
ffectiveness calculations.
nts
po
an
nt
ata
ssth
eatme
354
-------
0
(
©
-&
©
in
CM
u
UJ
UJ
0
0
5
omium Raw
GU
CO £
= S5
"• p
<
t
&
u
UJ
cc
a.
UJ
a
x
o
K
a
>
x
(|/Siu) uoiienuaouoa
355
-------
©
©
II
s
.o
a
Ui
UJ
u
e
u
BC
s
u
UJ
cc
oc
a
(l/fiui) uoijBJiuwuoQ iueny|3
356
-------
s
CXI
CM
II
1
>
p
©'
O1
s
o
'.P
i
— UJ
0
i
o
UJ
flC
a.
UJ
(1/BlU) UOHBJ1U83U03 )U8R|||a JU3UJJB8J1
357
-------
!N 0
iioiwaiMM03iiMny|3|MinJluinuiuin|V x
358
-------
-0-
1 •
)
©
e
®<
ffi
)
(
0
<5
©
Zinc Rtw Waste
8
ECTIV
ae
e
a I
J. ui
51«
W"" ^m
Ul ^~
K CA r:
C9
CA Ki
= o
"I
HYDROXIDE PREC
(I/Bui) uofjBJiuaouoo luan^g pneaij.aujz
359
-------
CM
II
V*
CO
1
«
u
e
u
ec
e
p
C9 O
c
Ul
fiC
a.
UJ
O
X
O
cc
(I/Bui)
360
-------
i
tu
u
UJ
u.
2 £ uj
J_ Z uj
> 2 <
u «« 2
u- <
X
o
cc
e
(l/fiui) uo|juwi83uoo iuan^g paisuj.
361
-------
^ ._
tions = 45
.
obse
0
0
0
•e
0
EFFECTIVENESS
ffl
©o
©
w
0
w
11
£
o>
u
e
U
O9
i
aw
TSS
- 19
^ 5«
U Uj M
DC CO r-
|g
"I
£
u
UJ
cc
a.
©
ROX
0
^
-B-
-€-
•0
(I/Bui) uojienuaouoQ
pajeaJi SSI
362
-------
o
CM
I
1-t
M
>
4)
3
30
z
o
o
CO
z
o
CJ
Cb
o
O
363
-------
FLANGE
WASTE WATCH
INFLUENT
DISTRIBUTOR
WASH WATER
• ACXWASH
SURFACE WASH
•ACXWASH
RCPLACtMCNT CARSON
CAKSON ACMOVAL FORT
TREATED WATER
SUPFORT PLATE
Figure VII-21
ACTIVATED CARBON ADSORPTION COLUMN
364
-------
OILY WATER
INFLUENT
WATER
DISCHARGE
MOTOR
DRIVEN
RAKE
i i t i /
BACK PRESS
VALVE
EXCESS
AIR OUT
LEVEL
CONTROLLER
Figure VII-22
DISSOLVED AIB. FLOTATION
365
-------
CCNVCYOft OfttVC
r—BOWL OKIVC
, DRYING
ZONK
UQUIO
OUTLET
SL.UOGC
INLET
REGULATING
RING
IMPCL.LC*
Figure VII-23
CENTRIHJGATION
366
-------
CS
u
3
H
Z
i3
X
a-
as
o
o.
-<
>
CO
Cil
367
-------
CONDUIT
TO MOTOft
INFLUENT
CONOUIT TO
OVCRLOAO
AUAJtM
EFFLUCNT
EFFLUENT CHANNCU
TURNTABLE
BASE
HANORAIU
DRIVE
r
WC1R
CENTER COUUMN
CSNTER CACC
STILTS
CKNTIW SCJIAFCH
Figure VII-25
GRAVITY THICKENING
368
-------
WASTE WATCH CONTAINING
DISSOLVED METALS OH
OTHER IONS
f\
REGENCRANT
'SOLUTION
•CIVCRTEJI VALVE
•DISTRIBUTOR
•SUPPORT
RCGCNCRANTTO KCUSC, _
, Off DISPOSAL *"**"
•OIVBSTER VALVE
WATER
FOR RCUSE OR
Figure 711-26
ION EXCHANGE WITH REGENERATION
369
-------
MACKOMOUCCUUES
0 ANO SOU OS
MEMSRANC
« 430
WATER
FEED-
PCRMEAT* (WATER)
* * f • * • •
1 *
°*.*0' ° ° *<
— *- o V° • *
o o * o c
• t /
, ' •
= • ° y
• •/
J / /•
y— MEMBRANE CROSS SECTION,
A IN TUBULAR, HOLLOW FIBER,
/7 OR SRIRAb-WOUNO CONFIGUR AT1ON
/• . • .f .
'° '? O.'o
Q * • " CONCENTRATE
O • (SALT3J
c
00. ._ 0 0
^. • .—-.._.—-• ^— ,
r
•
Q SALTS OK SOLIDS
MQUCCUt.CS
Figure 711-27
SIMPLIFIED REVERSE OSMOSIS SCHEMATIC
370
-------
PERMEATE
TUBC
ADHESIVE BOUND
SPtRAL MODULE
SACKING MATERIAL
MESH SPACER
MEMBRANE
SPIRAL MEMBRANE MODULE
PRODUCT WATER
POROUS SUPPORT TUBE PERMEATE
WITH MEMBRANE » 1
' BRACKISH
WATER
FCEO FLOW
I * ¥* »
PRODUCT WATER
TUBUUAR REVERSE OSMOSIS MOOUUE
3R1NE
CONCENTRATE
F'.OW
SNAP
RING
OPEN ENDS
OF FIBERS
_ EPOXY
TUBE SHEET
POROUS
BACK-UP DISC
CONCENTRATE
OUTLET
-END PUATE
POROUS FEED
DISTRIBUTOR TUBE —J
HOLLOW P1BER MODULE
Figure VII-28
REVERSE OSMOSIS MEMBRANE CONFIGURATIONS
371
-------
SANO
3-
-------
UUTRA^ILTRATION
MACROMOLECUUES
f • I 0-90
MEMBRANC
WATCH SALTS
•MEMBRANE
PERMEATE
••
••
**o**o *° * • o*°*«00*o**
• •
o
. •
• o
CONCENTRATS
o .o
r • • r • •
O OIL
• DISSOLVED SALTS AND LOW-MOLECULAR-WE1GHT ORGANICS
Figure VII-30
SIMPLIFIED OLTKAFILTRATION FLOW SCHEMATIC
373
-------
ocz
z°
SH
^
-1
o
£
o
CO
w ^
uj 5
Uz
^.
o 5
c H
a.
I
< UI
tr
Ed
H
en
>•
CO
z
o
H
-J
=3
d o
o
(T
U.
^
o
u.
n-
< UJ O
374
-------
FABRIC on wine
F1LTCR MCOIA
STKCTCHCO OVCft
MCVQUVtNQ OMUM
OIRCCTION or DOTATION
SOUOSSCRAFCO
err rtuT«n MCOIA
VACUUM
SOUMCC
CYUNOfttCAL.
TRUNNION
LIQUID FOACC
THROUGH
MCOIA IY
MCANS or
VACUUM
SQUIDS COLLECTION
uouta
LIQUID
Figure VII-32
VACUUM FILTRATION
375
-------
EVAPORATION
CONTACT COOLING
WATER
ANNEALING
QUENCH
WATER
COOLING
TOWER
SLOWDOWN
DISCHARGE
RECYCLED FLOW
MAKE-UP WATER
Figure VII-33
FLOW DIAGRAM FOR RECYCLING WITH A COOLING TOWER
376
-------
SINGLE RINSE
OUTGOING WATER
vwt
-* WORK MOVEMENT
—INCOMING WATER
DOUBLE COUNTERFLOW
RINSE
OUTGOING WATER
WORK
--» MOVEMENT
- INCOMING WATER
TRIPLE COUNTERFLOW
RINSE
~"*~1 i»— n . r*
f ! t i
i ' /* L ' J
. i f • -••• —• '-«i
. — TI*™' '^*T jF ' f
t ^} U.J
vJ x
1
OUTGOING WATER
WORK MOVEMENT
| 1 . INCOMING
L r -L - — t-
w
V
j
i i
*~»~J
tt^ i
._ WATER
Figure VII- 34
COUNTER COTBZST RINSING (TANKS)
377
-------
10001—
750
SOO
I
5
250
RMS* Staqes
Figure VII-35
EFFECT OF ADDED RINSE STAGES ON WATER USE
378
-------
SECTION VIII
COST OF WASTEWATER TREATMENT AND CONTROL
This section presents estimates of the costs of implementing the
major wastewater treatment and control technologies described in
Section VII. These cost estimates, together with the estimated
pollutant reduction performance for each treatment and control
option presented in Sections IX, X, XI, and XII, provide a basis
for evaluating the options presented and identification of the
best practicable technology currently available (BPT), best
available technology economically achievable (BAT), best demon-
strated technology (BDT), and the appropriate technology for pre-
treatment. The cost estimates also provide the basis for deter-
mining the probable economic impact on the copper forming cate-
gory of regulation at different pollutant discharge levels. In
addition, this section addresses nonwater quality environmental
impacts of wastewater treatment and control alternatives,
including air pollution, solid wastes, and energy requirements.
The first part of this section describes the general methodology
used to estimate compliance costs including representative plant
selection and the projection of the costs to the entire copper
forming industry. In the second part, the general assumptions
and terminology used in determining the costs are discussed. The
third part describes the computer model which was used to
estimate the costs generated since proposal. The fourth part
describes in detail the individual treatment technology modules.
In the fifth part, estimates for each of the five Treatment and
Control Options are discussed. Next, normal plant costs are
presented and discussed. Finally, energy requirements and
nonwater quality aspects of the regulation are considered.
COST ESTIMATING METHODOLOGY
Estimates of the costs that plants would incur to comply with the
various treatment options were determined in the following man-
ner: first, a representative population of plants was chosen,
considering such factors as production, wastewater flows, number
and type of operations, treatment in place, and discharge status.
Costs for these plants were then determined with the aid of a
computer model. The sum of these costs was multiplied by the
ratio of the total number of plants in the industry to the number
of plants in the representative population to obtain the esti-
mated cost impact on the entire industry.
The plants that were used for cost estimation were selected to
represent the characteristics of the total population of plants
in the copper forming category in terms of number and type of
379
-------
manufacturing operations present, wastewater treatment in place,
and production. In the copper forming category, 55 percent of
the direct dischargers and 52 percent of the indirect dischargers
practice only one major forming operation. In comparison, 57
percent of the direct dischargers and 58 percent of the indirect
dischargers chosen for cost estimation practice only one forming
operation. A comparison of the distribution of the number of
operations throughout the copper forming category with that of
the costed plants is presented in Table VIII-1.
The costed plants were also chosen so that the percentage of
plants in the costed group performing each operation approximated
the percentage of plants in industry performing that operation.
For example, 30 percent of the direct dischargers in the copper
forming industry perform hot rolling; 29 percent of the direct
dischargers in the costed group perform hot rolling. The costed
plants were also chosen so that their wastewater treatment in
place was representative of the copper forming industry. Plants
were divided into three categories with respect to the amount of
treatment they have in place: 'None1 (no treatment at all);
'Some1 (lime and settle, with or without oil skimming); and
'Extensive' (lime and settle and two or more additional treatment
steps). The percentage of plants from the costed group that fits
into each category approximates the percentage of plants from
industry that fits into each category. Table VIII-1 presents a
detailed comparison of industry and the costed group. In addi-
tion, the range of production among the costed plants (9 kkg to
180,000 kkg annually) approximates the range of production of
plants in the copper forming category.
Eight of the 12 plants that were visited and sampled as part of
the data gathering effort were chosen for costing because they
are representative of plants in the category in terms of treat-
ment costs. While the remaining four sampled plants provide
wastewater characterization data which were representative of the
major forming and ancillary operations found in the category,
they were not used to determine treatment costs. The inclusion
of these plants would have skewed the sample population towards
plants with multiple forming operations. Accordingly, several
non-sampled plants which practice single forming operations were
selected for costing. The plants selected for costing represent
a population comprised of approximately 54 percent single forming
operation plants and approximately 46 percent multiple forming
operation plants. As previously discussed, this distribution
approximates the makeup of dischargers in the category.
Costs were determined for 14 direct dischargers. For each plant,
a wastewater treatment system which accounted for any required
treatment already in place was designed for each technology
option. The computer model then performed a detailed treatment
380
-------
system design and costed any additional equipment required for
the system. The model also estimated the annual cost of operat-
ing and maintaining the treatment system.
The costs for the, 14 direct dischargers were then added, and the
sum was multiplied by 37/14, which is the ratio of the total
number of direct dischargers in the category (37) to the number
of plants selected for costing (14).
A similar approach was taken for indirect dischargers. Costs
were determined for 17 indirect dischargers. The sum of these 17
cost estimates was multiplied by 45/17, which is the ratio of the
total number of indirect dischargers in the copper forming cate-
gory (45) to the number of indirect dischargers selected for
costing (17).
DETERMINATION OF COSTS
Sources of Cost Data
Capital and annual cost data for the selected treatment processes
were obtained from three sources: (1) equipment manufacturers,
(2) literature data, and (3) cost data from existing plants. The
major source of equipment costs was contacts with equipment ven-
dors, while the majority of annual cost information was obtained
from the literature. Additional cost and design data were
obtained from data collection portfolios when possible.
Components of Costs
Capital Costs
Capital costs consist of two components: equipment capital costs
and system capital costs. Equipment costs include: (1) the pur-
chase price of the manufactured equipment and any accessories
assumed to be necessary; (2) delivery charges, which account for
the cost of shipping the purchased equipment a distance of 500
miles; and (3) installation, which includes labor, excavation,
site work, and materials. The correlating equations used to
generate equipment costs are shown in Table VII1-2.
Capital^ system costs include contingency, engineering, and con-
tractor's fees. These system costs, each expressed as a percen-
tage of the equipment cost, are combined into a factor which is
multiplied by the equipment cost to yield the total capital
investment. The components of the total capital investment are
listed in Table VIII-3.
381
-------
Annual Costs
The total annualized costs also consist of a direct and a system
component. The components of the total annualized costs are
listed in Table VIII-4. Direct annual costs include the follow-
ing;
o Raw materials - These costs are for chemicals used in
the treatment processes, which include lime, sulfuric
acid, alum, polyelectrolyte, and sulfur dioxide.
o Operating labor and materials - These costs account for
the labor and materials directly associated with opera-
tion of the process equipment. Labor requirements are
estimated in terms of manhours per year. A labor rate
of 21 dollars per manhour was used to convert the man-
hour requirements into an annual cost. This composite
labor rate included a base labor rate of nine dollars
per hour for skilled labor, 15 percent of the base
labor rate for supervision and plant overhead at 100
percent of the total labor rate. Nine dollars per hour
is the Bureau of Labor national wage rate for skilled
labor.
o Maintenance and repair - These costs account for the
labor and materials required for repair and routine
maintenance of the equipment. Maintenance and repair
costs were usually assumed to be 5 percent of the
direct capital costs based on information from
literature sources unless more reliable data could be
obtained from vendors.
o Energy - Energy, or power, costs are calculated based
on total nominal horsepower requirements (in kw-hrs),
an electricity charge of $.0483/kilowatt-hour and an
operating schedule of 24 hours/day, 250 days/year
unless specified otherwise. The electricity charge
rate {March 1982) is based on the industrial cost
derived from the Department of Energy's Monthly Energy
Review.
System annual costs include monitoring, insurance and amortiza-
tion (which is the major component). Monitoring refers to the
periodic sampling analysis of wastewater to ensure that discharge
limitations are being met. The annual cost of monitoring was
calculated using an analytical lab fee of $120 per wastewater
sample and a sampling frequency based on the wastewater discharge
rate, as shown in Table VII1-5.
382
-------
Insurance cost is assumed to be one percent of the total depreci-
able capital investment (see Item 23 of Table VIII-3). Amortiza-
tion costs, which account for depreciation and the cost of
financing, were calculated using a capital recovery factor (CRF).
A CRF value of 0.22 was used, which is multiplied by the total
capital investment (see Item 24 of Table VI I 1-4) to give the
annual amortization cost. Detailed information regarding the CRF
is provided in Appendix 2A to the Economic Impact Analysis for
the Effluent Standards and Limitations for the Copper Formina
Point Source Category.
Cost Update Factors
All costs are standardized by adjusting to the first quarter of
1982. The cost indices used for particular components of costs
are described below.
Capital Investment - Investment costs were adjusted using the
EPA-Sewage Treatment Plant Construction Cost Index. The value of
this index for March 1982 is 414.0.
SP?F?4on L3M Maintenance Labor - The Engineering News-Record
Skilled Labor Wage Index is used to adjust the portion of Oper-
ation and Maintenance costs attributable to labor. The March
1982 value is 325.0.
Maintenance Materials - The producer price index published by the
Department of Labor, Bureau of Statistics is used. The March
1982 value of this index is 276.5.
Chemicals - The Chemical Engineering Producer Price Index for
industrial chemicals is used. This index is published biweekly
in Chemical Engineering magazine. The March 1982 value of this
index is 362.6.
. - Power costs are ad j us ted by us i ng the pr i ce of
electricity on the desired date and multiplying it by the energy
requirements for the treatment module in kw-hr equivalents.
COST ESTIMATION MODEL
Cost estimation was accomplished using a computer model which
accepts inputs specifying the required treatment system chemical
characteristics of the raw waste streams, flow rates and treat-
ment system entry points of these streams, and operating sched-
ules. This model utilizes a computer-aided design of a waste-
water treatment system containing modules that are configured to
reflect the appropriate equipment at an individual plant. The
model designs each treatment module and then executes a costing
383
-------
routine that contains the cost data for each module. The capital
and annual costs from the costing routine are combined with
capital and annual costs for the other modules to yield the total
costs for that regulatory option. The process is repeated for
each regulatory option.
Each module was developed by coupling theoretical design informa-
tion from the technical literature with actual design data from
operating plants. This permits the most representative design
approach possible to be used, which is a very important element
in accurately estimating costs. The fundamental units for design
and costing are not the modules themselves but the components
within each module, e.g., the lime feed system within the chemi-
cal precipitation module. This is a significant feature of this
model for two reasons. First, it does not limit the model to
certain fixed relationships between various components of each
module. For instance, cost data for chemical precipitation sys-
tems are typically presented graphically as a family of curves
with lime (or other alkali) dosage as a parametric function. The
model, however, sizes the lime feed system as a funtion of the
required mass addition rate (kg/hr) of lime. The model thus
selects a feed system specifically designed for that plant.
Second, this approach more closely reflects the way a plant would
actually design and purchase its equipment. The resulting costs
are thus closer to the actual costs that would be incurred by the
facility.
Overall Structure
The cost estimation model consists of two main parts: a design
portion and a costing portion. The design portion uses input
provided by the user to calculate design parameters for each
module included in the treatment system. The design parameters
are then used as input to the costing routine, which contains
cost equations for each discrete component in the system. The
structure of the program is such that the entire system is
designed before any costs are estimated.
The pollutants or parameters which are tracked by the model are
shown in Table VII1-6.
An overall logic diagram of the computer programs is depicted in
Figure VIII-]. First, constants are initialized and certain var-
iables such as the modules to be included, the system configura-
tion, plant and wastewater flows, compositions, and entry points
are specified by the user. Each module is designed utilizing the
flow and composition data for influent streams. The design
values are transmitted to the cost routine. The appropriate cost
equations are applied, and the module costs and system costs are
384
-------
computed. Figures VIII-2 and VIII-3 depict the logic flow dia-
grams in more detail for the two major segments of the program.
System Input Data
Several data inputs are required to run the computer model.
First, the treatment modules to be costed and their sequence must
be specified. Next, information on hours of operation per day
and number of days of operation per year is required. The flow
values and characteristics must be specified for each wastewater
stream entering the treatment system, as well as each stream's
point of entry into the wastewater treatment system. These
values will dictate the size and other parameters of equipment to
be costed. The derivation of each of these inputs for costed
plants in the copper forming category will be discussed in turn.
Choice of the appropriate modules and their sequence for a plant
that is to be costed are determined by applying the treatment
technology for each option (see Figures X-l through X-5 pp.
465-469). These option diagrams were adjusted to accurately
reflect the treatment system that the plant being costed would
actually require. For example, if it were determined by
examining a plant's dcp that sodium bichromate was not used in
the plants pickling operation, then a chromium reduction module
would not be included in the treatment required for that plant.
In addition, if a plant had a particular treatment module in
place, that module would not be costed. Flow reduction modules
were not costed for plants whose waste stream flow rates were
already lower than the regulatory flows. The information on
hours of operation per day and days of operation per year was
obtained from the data collection portfolio of the plant beinq
costed.
The flow used to size the treatment equipment was derived as
follows: production and flow information was obtained from the
plant's dcp, or from sampling data where possible, and a produc-
tion normalized flow in liters per kkg was calculated for each
waste stream. This flow was compared to the regulatory flow,
also in liters per kkg, and the lower of the two flows was used
to size the treatment equipment. Regulatory flow was also
assigned to any stream for which production or flow data was not
reported in the dcp. The average raw waste concentrations of the
sampled plants were used as raw waste values for all costed
plants.
Model Results
For a given plant, the model will generate comprehensive material
balances for each parameter (pollutant, temperature and flowrate)
tracked at any point in the system. It will also summarize
385
-------
design values for key equipment in each treatment module, and
provide a tabulation of costs for each piece of equipment in each
module, module subtotals, total equipment costs, and system
capital and annual costs.
COST ESTIMATES FOR INDIVIDUAL TREATMENT TECHNOLOGIES
Introduction
Treatment technologies have been selected from among the larger
set of available alternatives discussed in Section VII after-
considering such factors as raw waste characteristics, typical
plant characteristics (e.g., location, production schedules,
product mix, and land availability), and present treatment prac-
tices. Specific rationale for selection is addressed in Sections
IX, X, XI, and XII. Cost estimates for each technology addressed
in this section include investment costs and annual costs for
depreciation, capital, operation and maintenance, and energy.
The basic cost data came from several sources. Some of the data
were obtained during on-site surveys. The majority of the cost
data were obtained through discussions with waste treatment
equipment manufacturers.
The specific assumptions for each wastewater treatment module are
listed under the subheadings to follow. Costs are presented as a
function of influent wastewater flow rate except where noted in
the process assumptions.
Costs are presented for the following control and treatment
technologies:
- Lime Precipitation and Gravity Settling,
- Vacuum Filtration,
- Multimedia Filtration,
- Chemical Emulsion Breaking,
- Oil Skimming,
- Chromium Reduction,
- Recyde-Cool ing,
- Spray Rinsing and Recirculation of the Rinse Water,
- Countercurrent Cascade Rinsing, and
- Contract Hauling.
Lime Precipitation and Gravity Settling
Precipitation using lime followed by gravity settling is a
fundamental technology for metals removal. In practice, either
qu i ck1ime {CaO) or hydrated 1ime (Ca(OH)2) can be used to
precipitate toxic and other metals. Hydrated lime is more eco-
nomical for low lime requirements since the use of slakers, which
386
-------
usage' are practical only for
Lime is used to adjust the pH of the influent waste stream to
'
.... K ,;
^vrS^fS SJgJSS £ LJ
on the influent metals concentrations and pH. The actual lime
cen^o/tnTth^V8 ?^aine^ by assumin5 anPeicess of 10 Per!
cent of the theoretical lime dosage. The effluent concentration*
•"
as
,1
least (total annualized) cost basis for a given flowr ate Th^
included
- Lime feed system (continuous)
K Storage units (sized for 30-day storage)
2. Slurry mix tank (5 minute retention time)
3. Feed pumps
4. Instrumentation (pH control)
- Polymer feed system
1. Storage hopper
2. Chemical mix tank
3. Chemical metering pump
- pH adjustment system
I' An?iff!!!iX.ta?k'.£iberglass (5 minute Detention time)
2. Agitator (velocity gradient is 300/second)
3. Control system
- Gravity settling system
1. Clarifier, circular, steel (overflow rate is 0.347
gpm/sq. ft., underflow solids is 3 percent)
387
-------
2. Sludge pumps (1), (to transfer flow to and from
clarifier)
Ten percent of the clarifier underflow stream is recycled to the
pH adjustment tank to serve as seed material for the incoming
waste stream.
The direct capital costs of the lime and polymer feed were based
on the respective chemical feed rates (dry Ibs/hour), which are
dependent on the influent waste stream characteristics. The
flexibility of this feature (i.e., costs are independent of other
module components) was previously noted in the description of the
cost estimation model. The remaining equipment costs (e.g., for
tanks, agitators, pumps) were developed as a function of the
influent flowrate (either directly or indirectly, when coupled
with the design assumptions).
Direct annual costs for the continuous system include operating
and maintenance labor for the feed systems and the clarifier, the
cost of lime and polymer, maintenance materials and energy costs
required to run the agitators and pumps.
The normal batch treatment system (used for 2,000 liters/hour<
flow < 11,800 liters/hour) consists of the following equipment:
- Lime feed system (batch)
1. Slurry tank (5 minute retention time)
2. Agitator
3. Feed pump
- Polymer feed system
1. Chemical mix tank
2. Agitator
3. Chemical metering pump
- pH adjustment system
1. Reaction tanks, (2), (8 hour retention time each)
2. Agitators (2), (velocity gradient is 300/second)
3. Sludge pumps (1), (to transfer sludge to dewatering)
4. pH control system
The reaction tanks used in pH adjustment are sized to hold the
wastewater volume accumulated for one batch period (assumed to be
8 hours). The tanks are arranged in a parallel setup so that
treatment occurs in one tank while wastewater is accumulating in
the other tank. A separate gravity settler is not necessary
since settling will occur in the reaction tank after precipita-
388
-------
tion has taken place.
dewatering stage.
The settled sludge is then pumped to the
If additional tank capacity is required in the pH adjustment sys-
tem in excess of 25,000 gallons (largest single fiberglass tank
C2SaSl*y f°? whlch cost data were compiled), additional tanks are
added in pairs. A sludge pump and agitator are costed for each
The cost of operating labor is the major component of the direct
annual costs for the normal batch system. For operation of the
batch lime feed system, labor requirements range from 15 to 60
minutes per batch, depending on the lime feed rate (5 to 1,000
pounds/batch). This labor is associated with the manual addition
ot lime (stored in 50 pound bags). For pH adjustment, required
labor is assumed to be one hour per batch (for pH control, sam-
?hin?'« Vflv2 °Peration' €tc->- Both the pH adjustment tank and
/^ i yeed, ?ys£em are assumed to require 52 hours per year
(one hour/week) of maintenance labor. Labor requirements for the
polymer feed system are approximately one hour/day, which
a^r?a?J^manl!al K***"?", °f dry PolVmer ™* maintenance
associated with the chemical feed pump and agitator.
,ann"al costs also include the cost of chemicals (lime,
polymer) and energy required for the pumps and agitators. The
me ,,and PQlymer use<* in the model are $47.30/kkg of
and *4'96/*9 of Polymer ($2.25/pound) , based on
fr°,m t!?e Cnemical Weekly Reporter (lime) and
from vendors (polymer).
For small influent flowrates (less than 2,000 liters/hour) it
Mow f
low flow
is
opposed
i. . t?tal annuali**<3 cost basis to select the
batch treatment system. The lower flowrates allow an
?£K*.five d?yS for the batch d"^ation, or holdup, as
eight hours for the normal batch system. However,
t0^al batch volume (based on ««ive day holdup
Ki ?allons' tne maximum single batch tank capacity
?i?UPi 1S ?SCrSas?d accordingly to maintain the batch volume
™ i 1!Vel\KCa?1^1 and annual costs for tne low flow sys-
tem are based on the following equipment:
- pH adjustment system
1.
2.
3.
Rapid mix/holdup tank (5 days or less retention time)
Agitator
Transfer pump
K« iS rec*4red for both holdup and treatment because
treatment is assumed to be accomplished during non-ooeratina
hours (since the holdup time is much greater than ?hT time
389
-------
required for treatment). A lime feed system is not costed since
line addition at low application rates can be assumed to be done
manually by the operator. A common pump is used for transfer of
both the supernatant and sludge through an appropriate valving
arrangement. Addition of polymer was assumed to be unnecessary
due to the extended settling time available.
As in the normal batch case, annual costs are comprised mainly of
labor costs for the low flow batch system. Labor requirements
are constant at 1.5 hours per batch for operation (e.g., pH con-
trol, sampling, etc.) and 52 hours per year
-------
Operating labor cost is the major component of annual costs,
which also include maintenance and energy costs.
Multimedia Filtration
Multimedia filtration is used as a wastewater treatment polishing
device to remove suspended solids not removed in previous treat-
ment processes. The filter beds consist of graded layers of
gravel, coarse anthracite coal, and fine sand. The equipment
used to determine capital and annual costs are as follows:
Influent storage tank sized for one backwash volume;
Gravity flow, vertical steel cylindrical filters with
media (anthracite, sand, and garnet);
Backwash tank sized for one backwash volume;
Backwash pump to provide necessary flow and head for
backwash operations;
Influent transfer pump; and
Piping, valves, and a control system.
The hydraulic loading rate is 7,335 lph/m* (180 gph/ft2) and the
backwash loading rate is 29,340 Iph/m* (720 gph/ft2). The filter
is backwashed once per 24 hours for 10 minutes. The backwash
volume is provided from the stored filtrate (see Figure VIII-6).
Effluent pollutant concentrations are based on the Agency's com-
bined metals data base for treatability of pollutants by filtra-
tion technology.
Chemical Emulsion Breaking
Chemical emulsion breaking involves the separation of relatively
stable oil-water mixtures by chemical addition. Alum, polymer,
and sulfuric acid are commonly used to destabilize oil-water
mixtures. In the determination of capital and annual costs based
on continuous operation, 400 mg/1 of alum and 2 mg/1 of polymer
are added to waste streams containing emulsified oil (see Figure
VIII-7). The equipment included in the capital and annual costs
for continuous chemical emulsion breaking are as follows:
- Alum and polymer feed systems:
1. Storage units
2. Dilution tanks
3. Conveyors and chemical feed lines
4. Chemical feed pumps
- Equalization tank (retention time of eight hours;
agitator sized for .03 horsepower per 3,785 liter
(1,000 gallon) capacity)
391
-------
- Rapid mix tank (retention time of 15 minutes; mixer
velocity gradient is 300/sec)
- Flocculation tank (retention time of 45 minutes;
mixer velocity gradient is 100/sec)
- Pump
Following the flocculation tank, the stabilized oil-water mixture
enters the oil skimming module. In the determination of capital
and annual costs based on batch operation, sulfuric acid is added
to waste streams containing emulsified oil until a pH of 3 is
reached. The following equipment is included in the determina-
tion of capital and annual costs based on batch operation:
- Sulfuric acid feed systems
1. S02 cost at $0.55/kg ($0.25 /lb),
1. Storage tanks or drums
2. Chemical feed lines
3. Chemical feed pumps
- Two tanks equipped with agitators (retention time of
8 hrs., mixer velocity gradient is 300/sec)
- Two belt oil skimmers
- Two waste oil pumps
- Two effluent water pumps
- One waste oil storage tank (sized to retain the waste
oil from ten batches)
The capital and annual costs for continuous and batch chemical
emulsion breaking were determined by summing the costs from the
above equipment. Alum, polymer and sulfuric acid costs were
assumed to be $.257 per kg ($.118 per pound), $4.95 per kg ($2.25
per pound) and $0.08 per kg of 93 percent acid ($.037 per pound
of 93 percent acid), respectively. (See Chemical Weekly
Reporter, March, 1982).
Operation and maintenance and energy costs for the different
types of equ ipment wh i ch compr ise the batch and cont inuous
systems were drawn from various literature sources and are
included in the annual costs.
392
-------
The cutoff flow for determining the operation mode (batch or con-
™?2!!8J« iS o5;,000. }itersf Per ho«r' above which the continuous
system is costed; at lower flows, the batch system is costed.
Oil Skimming
Oil skimming refers to the separation of the de-emulsified oil-
water mixture obtained from the continuous chemical emulsion
breaking operation. This separation is accomplished with a coa-
lescent plate-type separator (which is essentially an enhanced
API-type oil-water separator). Coal escent plate separators were
ESiLE equir®d f?Howing batch chemical emulsion breaking since the
« f L *? ' 4.1" Con3uncti°n with a belt type oil skimmer, served
as the oil-water separation tank. The costs of the belt skimmer
breaking cSS'(.S" ^ °f th'
Although the required separator capacity is dependent on many
factors, the sizing was based primarily on the influent waste-
?!£?„* rate' with the following design values assumed for the
remaining parameters of importance:
Parameter Nominal Design Value
Specific gravity of oil 0 85
Operating temperature (o F) gs*
Influent oil concentration (mg/1) 30,000
Extreme operating conditions, such as influent oil concentrations
greater than 30,000 mg/1, or temperatures lower than 68* F w™I
accounted for in the sizing of the separator.
The capital and annual costs of oil skimming included the follow-
ing equipment: j-w-nuw
Coalescent plate separator with automatic shutoff valve
and level sensor
Oily waste storage tanks (2-week retention time)
Oily waste discharge pump
Effluent discharge pump
e?«iVent ?iow ^ates UP fco 159,100 1/hr (700 gpm) are costed for a
single unit; flows greater than 700 gpm require multiple units.
The direct annual costs for oil skimming include the cost of
operating and maintenance labor and replacement parts. Annual
393
-------
costs for the coalescent separators alone are minimal and involve
only periodic clean out and replacement of the coalescent plates.
Chromium Reduction
This technology can be applied to waste streams containing sig-
nificant concentrations of hexavalent chromium. Chromium in this
form will not precipitate until it has been reduced to the tri-
valent form. The waste stream is treated by addition of acid and
gaseous SOZ dissolved in water in an agitated reaction vessel.
The SOZ is oxidized to sulfate while it reduces the chromium.
The equipment required for this continuous stream includes an S02
feed system (sulfonator), an H2S04 feed system, a reactor vessel
and agitator, and a pump. The reaction pH is 2.5 and the SOZ
dosage is a function of the influent loading of hexavalent
chromium. A conventional sulfonator is used to meter SOZ to the
reaction vessel. The mixer velocity gradient is 100/sec.
Annual costs are as follows:
SO2 feed system
1. SOZ cost at $0.55/kg ($0.25/lb),
2. Operation and maintenance labor requirements vary
from 437 hrs/yr at 4.5 kg S0z/day (10 Ibs S02/day)
to 5,440 hrs/yr at 4,540 kg S0z/day (10,000 Ibs
S02/day),
3. Energy requirements at 570 kwh/yr at 4.5 kg S0z/day
(10 Ibs S0z/day) to 31,000 kwh/yr at 4,540 kg
S0z/day (10,000 Ibs S0z/day).
H2 S04 feed system
1. Operating and maintenance labor at 72 hrs/yr at
37.8 Ipd (10 gpd) of 93 percent HZS04 to 200
hrs/yr at 3,780 Ipd (1,000 gpd),
2. Maintenance materials at 3 percent of the equip-
ment cost,
3. Energy requirements for metering pump and storage
heating and lighting.
- Reactor vessel and agitator
1. Operation and maintenance labor at 120 hrs/yr,
394
-------
2. Electrical requirements for agitator.
Figure VIII-8 presents the cost curve for chromium reduction.
Cooling Towers/Tanks
Cooling towers are used to recycle annealing water and solution
heat treatment wastewaters as a flow reduction measure for
recirculating flow rates above 3,400 1/hr (15 gpm). The minimum
flow rate represents the smallest cooling tower commercially
available from the vendors contacted. Conventional holding tanks
are used to recycle flow rates less than 15 gpm.
The required cooling tower capacity is based on the amount of
heat removed, which takes into account both the flow rate and
temperature range (decrease in cooling water temperature). The
recirculation flow rate through the cooling tower is based on the
BPT flow rate. The temperature range was based on a cold water
temperature of 85° F and an average hot water temperature for a
particular waste stream (calculated from sampling data). When
the hot water temperature was not available, or found to be below
95<> F, a value of 95° F was assumed, resulting in a range of 10°F
(95-85° F). The remaining significant design parameters, the wet
bulb temperature (ambient temperature at TOO percent relative
humidity) and the approach (of cold water temperature to the wet
bulb temp) are assumed to be constant at 75° F and 8° F,
respectively.
The capital costs of cooling tower systems include the following
equipment:
- Cooling tower (crossflow, mechanically-induced) and
typical accessories
- Piping and valves (305 meters (1000 ft.) carbon steel)
- Cold water storage tank (2 hour retention time)
- Recirculation pump, centrifugal
- Chemical treatment system (for pH, slime and corrosion
control)
For nominal recirculation flow rates greater than 159,100 1/hr
(700 gpm), multiple cooling towers are assumed to be required. A
holding tank system would consist of a holding tank and a recir-
culation pump.
The direct capital costs include purchased equipment cost,
installation and delivery. Installation costs for cooling towers
395
-------
were assumed to be 200 percent of the cooling tower cost based on
information supplied by vendors. Piping costs were the major
components of the cooling tower capital costs (see Figure
VIII-9).
Direct annual costs included raw chemicals for water treatment,
fan energy requirements, and maintenance and operating labor was
assumed to be constant at 60 hours per year. The water treatment
chemical cost was based on $5/gpm of recirculated water.
Spray Rinsing
Spray rinsing is the model treatment technology used for reduc-
tion of pickling rinse water. The flow used to determine spray
rinsing costs is equal to the regulatory pickling rinse flow.
A spray rinsing system consists of the following equipment:
- Tank/collection basin with level controller
- Spray nozzle and piping system
- Pump
- Conductivity meter
Capital costs of spray rinsing do not include the tank with level
controller since such a tank was already installed for existing
plants in this category (see Figure VI11-10).
The tank was converted to a spray rinsing operation by installing
the additional equipment previously listed. Teflon-lined steel
piping (48 feet), a stainless steel spray nozzle system complete
with a liquid strainer and shutoff valves, a pressure gauge,
conductivity meter and a centrifugal pump are assumed to be
required.
Installation of 50 percent and a retrofit allowance of 15 percent
of the purchased equipment costs were added to obtain the capital
costs.
Annual costs included five percent of the plant operating hours
as maintenance labor, maintenance materials cost as two percent
of the total purchased equipment cost and operating and mainte-
nance costs associated with pumping.
Countercurrent Cascade Rinsing
This technology is used to reduce water use in pickling rinse
operations for new plants. It involves a multiple stage rinsing,
with product and rinse water moving in opposite directions (more
detail may be found in Section VII p. 310). This allows for
significantly reduced flow over single stage rinsing by
396
-------
contacting the most contaminated rinse water with the incomina
product.
The countercurrent rinsing system is a three stage rinsing line,
consisting of the following equipment:
- Tanks (3), fiberglass
- Transfer pump (1), centrifugal
Agitation costs were also included as part of the countercurrent
cascade rinsing costs. A rinsing system was costed for each
separate line reported by a plant to be costed. In the case of
multiple lines, it was assumed that the total rinsing flow was
divided evenly among each line (see Figure VIII-10).
The capacity of each tank is usually determined by the size of
the product holding rack. Each tank is assumed to be 13,627
liters (3,600 gallons) and constructed of fiberglass (to handle
the dilute acidic solutions). Agitation was provided for the
last two tanks to ensure thorough rinsing. A centrifugal pump
was included to transfer water to the rinsing system. Flow
between tanks was accomplished by gravity.
Annual costs are based mainly on operation and maintenance costs
for the agitators and pump.
Contract Hauling
Concentrated sludge and waste oils are removed on a contract
basis for off-site disposal. The cost of contract hauling
depends on _the classification of the waste as being either
hazardous or rionhazardous. For nonhazardous wastes, a rate of
$0.106/liter ($0.40/gallon) was used in determining contract
hauling costs. This value is based on reviewing information from
several sources, including a paint industry survey, comments from
the aluminum forming industry, and literature sources. This cost
was within $0.013/liter of the cost data submitted by copper
formers during the comment period and obtained by telephone
contacts. The contract hauling cost fbr^nonhazardous waste was
used in this cost estimation because the AgeTtcy^beJJLeves that the
wastes generated from copper forming plants are not hazardous as
defined under 40 CFR 261. The capital cost associated with
contract hauling is assumed to be zero.
COSTS FOR TREATMENT AND CONTROL OPTIONS
The components of the five control and treatment options which
were considered as the bases for BPT, BAT, PSES, NSPS, and PSNS
are presented below. The five options are discussed in greater
detail in Section X (p. 447).
397
-------
Option 1_
For Option 1, costs were estimated for the following treatment
processes:
- Lime precipitation and clarification,
- Vacuum filtration,
- Chemical emulsion breaking,
- Oil skimming,
- Chromium reduction,
- Contract hauling,
- Spray Rinsing and recirculation of the
pickling rinse water for forged parts, and
- Recycle of hot rolling spent lubricant.
Option 2
For Option 2, costs were estimated for the following treatment
processes:
- All Option 1 processes, plus
- Cooling towers for annealing water and solution heat
treatment water, and
- Spray rinsing and recirculation of all pickling rinse
water.
Option 3
For Option 3, costs were estimated for the following treatment
processes:
- All Option 2 processes, plus
- End-of-pipe polishing multimedia filtration.
Option 4
For Option 4, costs were estimated for new plants for the
following treatment processes:
- All Option 3 processes, plus
- Countercurrent cascade rinsing in pickling operations.
Option 4 is the model treatment technology for new sources. As
discussed in Section X, p. 450, the Agency believes taht existing
copper forming plants do not have sufficient space to add
countercurrent cascade rinsing. The Agency believes that the
cost of installing countercurrent rinsing in a new plant would
not be greater than the cost of installing single stage or spray
rinsing at existing plants and in some cases may actually be less
because of decreased water use and pumping requirements.
398
-------
NORMAL PLANT COSTS
A normal plant is a theoretical plant which has each of the manu-
facturing operations covered by the category at a production
level that is the average level of the direct and indirect dis-
chargers in the category. The Agency developed a normal plant in
order to estimate pollutant removals, sludge generation, energy
requirements, and costs for new source dischargers. The charac-
teristics of a copper forming normal plant are presented in Table
VII1-7. The production attributable to each waste stream is
calculated by totaling the reported production for all discharg-
ers through that waste stream (from the dcp) and then dividing by
the number of dischargers in the industry (82). The normal plant
flows are the characteristic production times the production
normalized flow allowance at each option. In addition, a normal
plant was assumed to operate 16 hours per day, 5 days per week,
50 weeks per year.
The Agency has prepared engineering costs for the first four
options described above using a normal plant to provide an indi-
cation of the relative costs of these options for new plants to
install treatment.
The capital, annual operation and maintenance, and annualized
costs are shown in Table VII1-8. For plants with no treatment in
place, the cost of Option 4 is comparable to the cost for Option
2. Recalling that Option 4 is identical to Option 2 except that
Option 4 includes additional flow reduction and an end-of-pipe
polishing filter (multimedia), it can be seen that the reduction
in costs due to lower flows almost offsets the additional cost of
the polishing filter. The Agency did not include savings in
water costs between Options 2 and 4. When these savings are
taken into account, the difference in the costs between Option 2
and Option 4 is further reduced.
ENERGY AND NONWATER QUALITY ASPECTS
The following are the nonwater quality environmental impacts
(including energy requirements) associated with these regula-
tions.
A. Air Pollution
Imposition of BPT and BAT limitations and NSPS, PSES, and PSNS
will not create any substantial air pollution problems. The
technologies used as the basis for this regulation precipitate
pollutants found in wastewater which are then settled or filtered
from the discharged wastewater. These technologies do not emit
pollutants into the air.
399
-------
B. Solid Waste
EPA estimates that direct and indirect dischargers in the copper
forming category generated 39,000 kkg of solid wastes (wet basis)
in 1978 as a result of wastewater treatment in place. These
wastes were comprised of treatment system sludges containing
toxic metals, (including chromium, copper, lead, nickel, and
zinc), oil removed during oil skimming, and chemical emulsion
breaking sludges that contain toxic organics.
EPA estimates that BPT will contribute an additional 13,000 kkg
per year of solid wastes over that which is currently being
generated by the direct and indirect dischargers in the copper
forming category. BAT and PSES will increase these wastes by
approximately 11,000 kkg per year beyond BPT levels. These
sludges will necessarily contain additional quantities (and
concentrations) of toxic metal pollutants. The normal plant was
used to estimate the sludge generated at NSPS and PSNS and is
estimated to be a 10 percent increase over BAT and PSES. The
final rule provides a flow allowance for drawing spent lubricant,
in contrast to the proposed rule which was based on contract
hauling of this wastewater stream. The decrease in the total
amount of sludge generated from this change will not be
significant.
Estimates of the amount of solid waste generated currently by
copper formers and the incremental amount of solid waste gener-
ated as a result of installing the proposed options were calcu-
lated using the following approach. The amount of solid waste
generated by treatment in place was estimated using the current
discharge flows for direct and indirect dischargers. For the
purposes of estimating the volume of sludge generated by
chemical precipitation and sedimentation it was assumed that the
treatment system was operated using ten percent excess lime, and
that the hydroxide sludge resulting from sedimentation was con-
centrated to 20 percent solids using vacuum filtration. Thus
applying the percentage of the industry with treatment in place
(70 percent of direct dischargers and 31 percent of indirect
dischargers), the amount of sludge currently generated was
calculated. The incremental amount of sludge generated under the
proposed BPT were then calculated by assuming that the portion of
the flow not currently treated would be treated using chemical
precipitation and sedimentation. The incremental amount of
sludge generated under the proposed BAT and PSES was calculated
based on the assumption that flow reduction measures selected
reduce the overall plant flow by approximately 60 percent.
The final rule is based on an increase from 0 to 85 1/kkg in the
flow allowance for drawing spent lubricant. This flow allowance
permits the treatment of drawing spent lubricant and thereby may
400
-------
decrease the estimated total solid waste generated by the copper
forming industry as a result of this regulation.
The Agency examined the solid wastes that would be generated at
copper forming plants by the suggested treatment technologies and
believes they will not be considered hazardous under Section 3001
of the Resource Conservation and Recovery Act (RCRA). This
judgment is made based on the recommended technology of lime
precipitation. By the addition of a 10 percent excess of lime
during treatment, similar sludges, specifically toxic metal
bearing sludges, generated by other industries such as the iron
and steel industry passed the EP toxicity test. See 40 CFR Part
261.24 (45 FR 33084 (May 19, 1980)). Data from one copper
forming plant indicated that the lime and settle sludge failed
the EP toxicity test but further investigation revealed that the
plant was not using excess lime as required by the model tech-
nology. Additional data from another copper forming plant indi-
cates that their wastewater sludges are not hazardous by RCRA
standards. Thus, the Agency believes that the copper forming
wastewater sludges will not be found toxic if the recommended
technology is applied. Since the copper forming solid wastes are
not believed to be hazardous, no estimates were made of costs for
disposing of hazardous wastes in accordance with RCRA
requirements.
Although it is the Agency's view that solid wastes generated as a
result of these guidelines are not expected to be classified as
hazardous under the regulations implementing Subtitle C of the
Resource Conservation and Recovery Act (RCRA), generators of
these wastes must test the waste to determine if the wastes meet
any of the characteristics of hazardous waste. See 40 CRF Part
262.11 (45 FR 12732-12733 (February 26, 1980)). The Agency may
also list these sludges as hazardous pursuant to 40 CFR Part
261.11 (45 FR at 33121 (May 19, 1980), as amended at 45 FR 76624
(November 19, 1980)).
If these wastes are identified as hazardous, they will come
within the scope of RCRA's "cradle to grave" hazardous waste man-
agement program, requiring regulation from the point of genera-
tion to point of final disposition. EPA's generator standards
require generators of hazardous copper forming wastes to meet
containerization, labeling, record keeping, and reporting
requirements; if copper formers dispose of hazardous wastes off-
site, they would have to prepare a manifest which would track the
movement of the wastes from the generator's premises to a per-
mitted off-site treatment, storage, or disposal facility. See 40
CFR Part 262.20. The transporter regulations require transpor-
ters of hazardous wastes to comply with the manifest system to
assure that the wastes are delivered to a permitted facility.
See 40 CFR Part 263.20 (1981). Finally, RCRA regulations estab-
401
-------
lish standards for hazardous waste treatment, storage, and dis-
posal facilities allowed to receive such wastes. See 40 CFR
Parts 264 and 265.
Even if these wastes are not identified as hazardous, they still
must be disposed in a manner that will not violate the open dump-
ing prohibition of Section 4005 of RCRA. The Agency has calcu-
lated as part of the costs for wastewater treatment the cost of
hauling and disposing of these wastes in accordance with this
requirement.
C. Consumptive Water Loss
Treatment and control technologies that require extensive recy-
cling and reuse of water may require cooling mechanisms. Evapor-
ative cooling mechanisms can cause water loss and contribute to
water scarcity problems—a primary concern in arid and semi-arid
regions. While this regulation assumes water reuse, the quantity
of water involved is not regionally significant. We conclude
that the consumptive water loss is insignificant and that the
pollution reduction benefits of recycle technologies outweigh
their impact on consumptive water loss.
D. Energy Requirements
The Agency believes that most direct dischargers will move
directly into compliance with BAT from existing treatment; there-
fore, EPA estimates that the achievement of BAT effluent limita-
tions will result in a net increase in electrical energy consum-
ption of approximately 0.6 million kilowatt-hours per year. To
achieve the recommended BAT effluent limitations, a typical
direct discharger will increase total energy consumption by less
than 1 percent of the energy consumed for production purposes.
NSPS will not significantly add to total energy consumption
because new source equipment and pumps will be smaller and will
therefore use less energy (due to the decreased flows). A normal
plant was used to estimate the energy requirements for a new
source. A new source wastewater treatment system will add
122,000 kilowatt-hours per year to the total industry energy
requirements.
The Agency estimates that recommended PSES will result in a net
increase in electrical energy consumption of approximately 0.5
million kilowatt-hours per year. To achieve recommended PSES, a
typical existing indirect discharger will increase energy con-
sumption by less than 2 percent of the energy consumed for pro-
duction purposes. PSNS, like NSPS, will not significantly add to
total energy consumption based on a normal plant calculation.
402
-------
Table VIII-1
DISTRIBUTION OF COSTED COPPER FORMING PLANTS
DIRECT DISCHARGERS
Distribution by Operation
Percent
of Direct
Operation Dischargers Percent of Posted Group
Hot Rolling 30 4/14 - 29
Cold Rolling 40 6/14 = 43
Drawing 68 10/14 = 71
Forging 5 2/14 = 14
Extrusion 33 5/14 * 36
Distribution by Number of Operations at a Given Plant
Percent
Number of of Direct
Operations Dischargers Percent of Costed Group
1 55 8/14 - 57
2 25 2/14 - 14
3 8 1/14 = 7
4 10 3/14 - 21
Distribution by Treatment-in-Place
Percent
Treatment- of Direct
in-Place Dischargers Percent of Costed Group
None 35 5/14 = 36
Some 52 8/14 = 57
Extensive 13 1/14*7
403
-------
Table VIII-1 (Continued)
DISTRIBUTION OF COSTED COPPER FORMING PLANTS
INDIRECT DISCHARGERS
Distribution by Operation
Percent
of Indirect
Operation Dischargers Percent of Costed Group
Hot Rolling 30 5/17 - 29
Cold Rolling 41 7/17 - 41
Drawing 80 14/17 = 82
Forging 6 1/17=6
Extrusion 19 3/17-18
Distribution by Number of Operations at a Given Plant
Percent
Number of of Indirect
Operations Dischargers Percent of Costed Group
1 52 10/17 - 58
2 26 3/17 - 18
3 11 3/17 - 18
4 9 1/17 = 6
Distribution by Treatment-in-Place
Percent
Treatment- of Indirect
in-Place Dischargers Percent of Costed Group
None 44 8/17 - 47
Some 39 6/17-35
Extensive 17 3/17 = 18
404
-------
£
•H
^3
•t*4
rH
5
O
«
Of
c
Co
06
en
en
•
o
N/
0.
V
m
CM
.
o
o
•
in
V
&
N/
en
en
«
o
8
o
CM*
V
CO
\/
o
o
m
GO
CN
CO
V
o
m
o
o
v
H
N/
V
N/
O
CM
I
•i-t
I
3
en >i
£
^-n
s~*
O
00
• ON
OCM
• .<~
O H
m
.in i—,
CO
»
CM
o ON
\o ON oo en
P^s ^^ C3 C?
• m •
-------
V
to
V
o
o
V
to
V
o
o
o
CM
CO
V
to
V
m
V
SS
V
O
o
V
>H
V
o
O
O
m
CO
a
s
•*><
i
s
CM
x-\
CQ
*^ ^J
CM vO
00 00
vo in
co
O
o
I
x->
x-xoQ
- 37
sa
CM
-*^-x
3
CM
^ CM ~^-sQ\ ^f
P"1*1 «CO • 00
. 0> I CM O
v- ,— x <1>
H n n
oo •
CO CLi
\O X
O^
P*—^ .
oo i— 0,0
2xS +
O
§
O\
T— VO
CO
S
x^ in
>* co
N-X CO
00 OCM
CM O ><
CO C
00 + .3
CM OO
O*J GO ^O
+ ,-vinr-
^H P** ^3
CM
^ O—•
O »— pi'
00 yt
CM « 0)
II II
S
m
•8
0)
to
4J
09
•8
£
•o
Of
^
to
0)
to
b
CO
o
4J
2
I
CO
406
-------
•H
-o
V.
W
o
m
CO
V
pL|
NX
O
•^af
CM
V
>
N/
m
8
^/
^^
V
CM
V
^>
S/
8
S
"*^
S
s/
£>
\/
8
m
N^
CM"
V
^i
V
8
m
V
^>
V
I
8
m
V
«!
CO
V
m
o
in
\/
•^3
CO
V
m
CM
JJ
CO
o
-(-
8
00
m o
II II
O -a!
—
00
CM
,
<—
x^
^
i
ON
^~
*~og
+ >*
•^j* x_x
•«Tin
• i
o --
^_
CO XO
II II
u <;
ON
OO
O
,
r^
i
^~
CO
CM
r-
co
CM
+ >"
CO ^
coin
* i
CO O
CM i-
CO XO
II R
O <
5
CO
•
CO
1
vO
R
vO
T-
^CM
+ ?
^^ ""^
CMCO
CO 1
.0
ON *~
vO X
K
O
CM
r*. S
§m
m
CM 3r
m o
• •
0 0
i- CO
CM
ON
00
CM
i
So
II II
u<
w
CO
9
2
a
co
•u
.0
u
o
o
4J
0)
w
u
-------
Continued
D Tl
IES
-2
S i
1 £Q
H H SB
H
8
O
408
-------
EH
Z
Ed
32
EH
CO
CD
rH
-O
cO
H
a,
H
O
EH
CO
EH
Z
Z
o
PH
S
o
u
JJ
09
o
U
s
CD
JJ
M
^j
B CD
CD 42
Uga
B
r-t £
Z
cfl
r-l
CD
*O
O
s
B
O
1-1
4-1
CO
JJ
09
O
O
(-1
cfl
JJ
«H
Ou
Cfl
o
JJ
o
CD
^J
HH
Q
09
09
o
u
r-l
Cfl
•r-l
O-
Cfl
U
CO
r-l
3
o
s
CO
r-l
CO
CQ
t-
,_
g
CD
4J
i- CM
c
B S -H
CO CO
JJ JJ'O
•H .-1 <0
T3
4-14-13
O O r-l
O
&$ a* c
O O M
c
o
*iH
JJ
cfl
JJ
c
ty
3
JJ
CO
C
«r4
OS
00
r-l fj
Cfl .H CO
O O- r*
•r4 .rJ 3
1-1 O- W
JJ O
CJ *O rH
CO rl O
rH CO C
W >< Ed
CM CO "3"
"-O
_jrj
00
o
4=
t— JJ
B CM
CD
JJ 43 CO
T-t S
CO CO
C JJ 4J
•t-l O -«H
T3 JJ +
at o
*O O T—
*^ 4J
r— 1 B
O CO CO
C CD JJ
r-l CO r-l
CD
O
C
cfl JJ
5 CO
O O
rH O
CO CD
r-H
JJ 3
QO-H T3
C 44 O
•rl O S
av«
3 co cfl
PLI OS W
O
m^o I-**
o
«_
J
00
o
1-1
f*
JJ
oo
r** co
u B
S CD
CD I-- CO JJ
JJ JJ >H
-HBO
CO C +
4-4 JJ JJ
O *'H O P""*
o
*« 4-1 4-4 09
in o s
• CD CD
CM 8* QJ JJ
r- O CO r-l
^_t
CO
00
r-l
,j^
o« V4
o
• S
•H i-t
e co
T> >, JJ
-^ c o
00 O 0
C "H 00
•H 4J C 4->
I-i cj T4 C
CD 3 H CO
CD Vt O r-l
C JJ JJ P-i
*»H CQ iH
00 C C r-l
C O O cfl
W 0 S JJ
o
oo cr» o *-
CO
r*
00
o
1-1
JJ
CM
r—
CO
,- T- e.
r- t- CD
JJ
6 B-rl
CD CO
JJ 4J ^
•r-4 .fH
^~
4-4 4-1 t-
0 O
&•? frS CO
mow
i— »— M
W
09
O
CJ
CD C
CO O
4-1 *
0 C
O r-t
00 CD
C r-l
1-1 Cfl
3 -H
'O O
CD
JJ M
CO OH
CD CO
M O
CO
W r-l
C CO
r— 1 W
O
EH
in vo
vO
•H t-l
t-H
CO CO
[ 1 'Q
CQ
o *o
0 C
CO
rH
Cfl »
JJ C
•rl O
CU'r*
Cfl JJ
CJ Cfl
rH
JJrH
CJ CO
CD W
i-l CO
Q -r4
Cfl
O
JJ
*o
CD
JJ
3
O
i-i
cu
1-1
CO
cfl
u
W
cO
43
JJ
B
cO
CD
l*
JJ
00
43
U
cO
(U
%j
o
4-1
O
O
ON
»
^?
^^v
CD
JO
O
W
*rj
CO
S
3
CO
CO
cO
CD
1-1
CD
IS
09
JJ
CO *
O W
o c
CD
OCS
C w
iH CO
PL, (0
f^4 JJ
42
•
T3
CO
C
•H
S
r4
CD
JJ
CD
*O
CO
1-1
CD
U
CO
W
09
O
O
00
C
«iH
W
O
JJ
•H
C
o
B
B*
o
43
44
O
C
o
•rl
JJ
CO
C
cfl
rH
o-
X
CO
c
cO
I-l
o
4-1
CD
00
Cfl
Orf
CD
CD
CO
CJ
409
-------
cd
01
r-l
43
cd
H
CO
H
CO
o
o
a
Ed
z
z
O
H
en
H
Z
w
z
o
o-
§
4J
n
o
0
01
T3
o
B
B
O
M-l
CO
4J
CO
o
o
r-l
cd
c
4J
u
a>
Vi
1-1
Q
-T
CM
43
00
3
o
Vi
43
•—
CM
n
43 0 -O B
^O ^O ^O
^™* fl) ^^ ^^
e o B B
0) C 01 01
f4 O *H *r4
O
tii it [ n_j M
o o
01 fe
*< 01 H Q£i
O W«- O
0)
4J
-^
•^^
+
o
CM
B
0)
4J
I-l
CO
4J
CO
o
o
Vt
S 0)
0)43
*j e
0)
T3
I
0)
Vi
cd
03
o
CM
o
00 -i-l
C 01
*Oi-i o cd
cd vi c
01 o cd -H
J3 4J V.
cu c ra c
> o c
t—CM cn
CN (N CM CN
01
4J
CO
o
0)
cd
3
c
c
m
CM
Vi
o
,Q
cd
r-l
00
c
4-1
cd
^J
01
P-
o
»
x
00
Vl
01
c
0)
.
01
rH
cd
•H
Vl
01
4->
cd
E
3
2
M-l
O
CO
4J
DO
O
o
0)
•o
3
o •
r* tj
i-l i-l
cd
CO CU
4J 01
CO Vl
o
O 'O
c
i— i cd
cd
3 0)
c o
c c
cd cd
c
0 4J
01 C
Vl -H
1-1 cd
a B
cd
.
r—
0)
r-l
43
cd
g
o
Vi
4-1
TD
0)
C
"cd
4J
43
O
4J
C
01
B
CO
01
>
C
-j
•^^
01
r-l
43
cd
1-1
o
01
Vl
CU
0)
T3
r-l
cd
4J
O
4J
0)
43
JJ
CO
1-1
\o
T—
•
CO
4-)
CO
O
O
00
c
1-1
Vi
o
4-1
1-1
c
o
B
M-l
O
C
o
1-1
4J
cd
c
1-1
B
Vi
01
4_)
01
TJ
CO
CJ
4J
O
c
o
•H
4J
cd
£3
cd
i—i
a
M
01
C
cd
Vi
o
M-l
01
oc
cd
T3
C
cd
c
o
T)
cd
i-)
o
CU
Vi
Cu
01
T3
Vi
O
M-l
4J
(3
3
O
O
O
cd
o
4-1
T3
0)
01
CO
cd
S
^•s
b
Qd
O
^-^ '
Vi
o
4-)
O
cd
M-l •
00
xc
tj ,^J
CU O
> c
o cd
o c
CU -H
V< M-l
rH U_1
cd o
4->
•H 4J
CU CO
ed O
CU O O
B
01
4_)
M
43
0)
01
CO
o
01 CU
4343
H 4J
T3
410
-------
Table VIII-5
WASTEWATER SAMPLING FREQUENCY
Wastewater Discharge
(Liters Per Day)
0 - 37,850
37,851 - 189,250
189,251 - 378,500
378,501 - 946,250
946,250+
Sampling Frequency
Once per month
Twice per month
Once per week
Twice per week
Three times per week
411
-------
Table VIII-6
COST PROGRAM POLLUTANT PARAMETERS
Parameter Units
Flowrate liters/hour
pH pH units
Temperature °F
Total Suspended Solids mg/1
Acidity (as CaC03> mg/1
Aluminum mg/1
Ammonia mg/1
Antimony mg/1
Arsenic mg/1
Cadmium mg/1
Chromium (trivalent) mg/1
Chromium (hexavalent) mg/1
Cobalt mg/1
Copper mg/1
Cyanide (free) mg/1
Cyanide (total) mg/1
Fluoride mg/1
Iron mg/1
Lead mg/1
Manganes e mg/1
Nickel mg/1
Oil and Grease mg/1
Phosphorous mg/1
Selenium mg/1
Silver mg/1
Thallium mg/1
Zinc mg/1
412
-------
r-.
i
t-i
r-l
M
£»•
01
*
^^
CO
H
I
O
g-l T—
•55
j ^
< r-(
2 N«/
OS
0 5
Z 0
O &H
M
s
o
£t>
OS
W
IX
O
^
ca
X
H
"*
C
O
JJ
o.
o
en
C
cO
CN
09
C
o
»J
•^^
JJ
o
o
m
-o
c
CO
^-
09
C
o
•H
JJ
o
m
in cn moo
ON cn CN ON O
t— en T— oo o
m
*n cn in o o
ON cn CN ON o
• • • • •
«— en «— co o
m
m en moo
ON cn CM O O
• _ • * •
«— en •— m O
en
*— o
-------
00
o
CM
CM O
• •
r- O
i
O
3
flt«
i
b
SB
c 9
**"4 ^b
4J
H? QH
O 3
O
r- O
>-4 W
KH ^p*
M H
to
C
O
•^
4J
O|
O
m
O
CO
«*> OJ O
• • •
O O —
O
*
o
^ _ o «-
o
•
o
0)
O
CO
H
CO
cd
H
o
o
14
0-
c
o
4J
OJ
Lj ^9
41 cd
a. 4>
o *
occo
5 4)
03
a
C
z:
O
O
O
O
ON
41
DC
e
a)
O
w 5
1 5
2 3
00
C 00
** c
c
06
00
c
•H
*4
^e
06
e
00
w
M
CO
00
e
^ oo i oo
U V C W
04 Eb flC ' &^
I
J
Of
w
aj
14
CO
CO
e
a)
ai
4J
to
4J
w
OB
O
i
41
a
«
414
-------
Table VIII-8
SUMMARY OF COpPgR FORMING NORMAL
Option 1
Option 2
Option 3
Option 4
COSTS ($1982)
Option 1
Option 2
Option 3
Option 4
Capital Cost
1,194.900.
1.182,800
1,232.900
1.233,200
Annual Operation and
Maintenance Cost (0&M>
' " '!'I*"H I IN ill !•»!•! n if" lll.l ]••**
763,800
756,80Q
779,200
779,900
Annualized1
Cost
1,026,700
1,017.000
1,050,500
1,051,200
1 Using a capital recovery factor of 0,22.
415
-------
Input
User-Specified
Variable*
Executive
Routine to C»ll
Inquired Modules
Call Cost
Equations For
Each Module
Compute
System
Costs
Output
Costs
Figure VIII-1
GENERAL LOGIC DIAGRAM OF COMPUTER COST MODEL
416
-------
now AND
coNCMfiwnoM
HtOMMWVKM*
MODULI
Figure VIII-2
LOGIC DIAGRAM OF MODULE DESIGN PROCEDURE
417
-------
DESIGN VALUES
AND CONFIGURATION
FROM MATERIAL
BALANCE PROGRAM
CALLMOOULE
SUBROUTINES
J
1
i j
MODULE 1
COMPONENTS
i
'
! * '
MODULE 2
COMPONENTS
i j
i
CALL COST
EQUATIONS
i
CALL COST
EQUATIONS
• • •
<
MODULE N
COMPONENTS
i
'
i
i
CALL COST
EQUATIONS
I
I
COST
EQUATIONS
COMPUTE
SUMMED
MODULE
COSTS
COMPUTE
SYSTEM
COSTS
I
OUTPUT
COSTS
CRETURN FOR\
NEXTPtANTj
Figure VIII-3
LOGIC DIAGRAM OF THE COSTING ROUTINE
418
-------
e
x
X
O
z
o
UJ
£
.j
o
S
ui
U
e
I
>
0)
60
O
H
%
H
M
CO
Q
§
H
8
o
CO
H
en
O
O
(* 38. Hoavw) sisoo ioaaio ivioi
419
-------
m
i
>
-------
«o
o
ID
O
ff
z
<•> i
2 z
o
p
oe
\£>
I
M
l-l
M
-------
<
10
o
m
O
o
IU
E
^
O
o
I
n
O
1
s
H
H
>
0)
60
•H
(* 28. HOBVH) S1SOO 1O3UIQ1V1OX
422
-------
If)
o
o
n
o.
O
o
o
Ul
tt
2
S
O
BE
O
B
I
GO
bO
•rl
O
»
Q
H
O
CO
H
CO
O
O
I ' '
10
o
18 28. HOHVW) S1SOO J.03dlO 1V1OJL
423
-------
---v
*e
m . — Z
- HOLD1NC
. _ _ <
-------
to
o
U>
o
O
O £3
-t H
I W
>
0)
60
•rH
O
CO
O
CJ
CM
o
m
o
is zs, Hoyvwl sisoo loauia iviox
425
-------
-------
SECTION IX
BEST PRACTICABLE CONTROL TECHNOLOGY
CURRENTLY AVAILABLE
This section identifies the effluent characteristics attainable
through the application of best practicable control technology
currently available (BPT), Section 30Kb)(1)(A). BPT reflects
the existing performance by plants of various sizes, ages, and
manufacturing processes within the copper forming category, as
well as the established performance of the recommended treatment
technologies. Particular consideration is given to the treatment
already in place at plants within the data base.
The factors considered in identifying BPT include the total cost
of applying the technology in relation to the effluent reduction
benefits from such application, the age of equipment and facili-
ties involved, the manufacturing processes employed, and nonwater
quality environmental impacts (including energy requirements).
In general, the BPT level represents the average of the best
existing performances of plants of various ages, sizes, proces-
ses, or other common characteristics. Where existing performance
is uniformly inadequate, BPT may be transferred from a different
subcategory or category. Limitations based on transfer of
technology are supported by a rationale concluding that the
technology is, indeed, transferable, and a reasonable prediction
that it will be capable of achieving the prescribed effluent
limits (see Tanner's Council of America v. Train, 540 F.2d 1188
Uth Cir. 1976). BPT focuses on end-of-pipe treatment rather
than process changes or internal controls, except where such
practices are common industry practice.
TECHNICAL APPROACH TO BPT
The Agency studied the copper forming category to identify the
manufacturing processes used and wastewaters generated during
copper forming. EPA collected information from industry by data
collection portfolios, and by sampling and analyzing wastewaters
from specific plants.
Some of the factors which must be considered in establishing
effluent limitations based on BPT have already been discussed.
The age of equipment and facilities and processes employed were
taken into account in the discussion of subcategorization
(Section IV, p. 67). Nonwater quality impacts and energy
requirements are considered in Section VIII (p. 399).
In making technical assessments of data and reviewing manufactur-
ing processes, indirect and direct dischargers have been consid-
427
-------
ered as a single group. An examination of plants and processes
did not indicate any process differences based on the type of
discharge, whether it be direct or indirect. However, in deter-
mining the technical basis representing the average of the best
existing performance, EPA considered only direct dischargers.
Wastewater produced by the deformation operations contains signi-
ficant concentrations of oil and grease, toxic organics, sus-
pended solids, and toxic metals. Surface cleaning produces a
rinse water in which significant concentrations of oil and
grease, toxic organics, suspended solids, and toxic metals are
found. The other surface treatment wastewaters have similar
characteristics.
BPT for the copper forming category is jjased upon common treatr-
ment of combined streams. The general treatment schemiForBPT
istoapplyLime an? settle technology to remove metals and
solids from the combined wastewaters. ""Separate preliminary
treatment steps for chromium reduction, chemical emulsion Hreak-
ing, and oil skimming are to be utilized when required, as well
as spray rinsing of forged parts. The BPT effluent concentra-
tions are based on the performance of chemical precipitation and
sedimentation (lime and settle) when applied to a broad range of
metal-bearing wastewaters. The basis for lime and settle perfor-
mance is set forth in substantial detail in Section VII (D. 263).
* "7"1/ /
/**/<
For each of the wastewater sources, a specific approach was fol-
lowed for the development of BPT mass limitations. To account
for the fact that plants with greater production will require
greater water usage, a unit of production or production normal-
izing parameter (PNP) was determined for each waste stream which
could then be related to the flow from the process to determine a
production normalized flow. Selection of the PNP for each pro-
cess element is discussed in Section IV. Each process was then
analyzed to determine (1) whether or not included operations
generated wastewater, (2) specific flow rates generated, and (3)
the specific production normalized flows for each process.
Production normalized flows presented in Section V were analyzed
to determine which flow was to be used as part of the basis for
BPT mass limitations. The selected flow (referred to as a BPT
regulatory flow or BPT flow) reflects the water use controls
which are common practices within the industry. The BPT flow is
based on the average of all applicable data.
The general assumption was made that all wastewaters generated
were combined for treatment in a single or common treatment sys-
tem. A disadvantage of common treatment is that some loss in
pollutant removal effectiveness may result where waste streams
containing specific pollutants at treatable levels are combined
428
-------
with other streams in which these same pollutants are absent or
present at very low concentrations. Since treatment systems con-
sidered as the basis for BPT are primarily for metals, oil and
grease, and suspended solids removal, and because they are found
in most waste streams in treatable quantities the Agency did not
reject common treatment. In addition, existing plants had one
common treatment system in place, and a common treatment system
is reasonable in terms of cost and effectiveness. Both treatment
in place at copper forming plants and treatment in other catego-
ries having similar wastewaters were evaluated (see Section VII).
The overall effectiveness of end-of-pipe treatment for the
removal of wastewater pollutants is improved by the application
of water flow controls within the process to limit the volume of
wastewater requiring treatment. The controls or in-process tech-
nologies recommended under BPT include only those measures which
are demonstrated within the category: water conservation, recy-
cle of hot rolling process water, recirculation of cold rolling
and drawing lubricants, and for forged parts, spray rinsing and
recirculation of pickling rinse water. Methods of water conser-
vation are discussed in detail in Section VII under 'Reduction of
water Use (p. 307); spray rinsing is also discussed in Section
vii. Recycle of hot rolling process water was included because
it is widely demonstrated in the copper forming catgory; nine of
the twelve plants that reported water application and discharge
5 «5 reported recycling. Recycle rates ranged from 87 percent
to 99.9 percent.
The Agency usually establishes wastewater pollutant limitations
in terms of mass rather than concentration. This approach limits
the total amount of pollutants discharged, thereby preventing the
U?fi ?llutlon as a treatment method. For the development of
ettluent limitations, mass loadings were calculated for each
operation. This calculation was made for each forming and ancil-
1fry operation. The mass loadings (milligrams of pollutant per
,1. t°?ram of Production unit - mg/off-kg) were calculated bv
multiplying the BPT flow (1/kkg) by the concentration achievable
using the BPT treatment system (mg/1) for each pollutant param-
eter regulated under BPT. The flows may be found in Table IX-1-
£T? o«eftment ?ffectiveness concentrations are presented in Table
VII-20 (p. 336).
REGULATED POLLUTANT PARAMETERS
Pollutant parameters were selected for regulation in the copper
forming category because of their frequent presence at high con-
centrations in untreated wastewaters. Chromium, copper, lead,
nicKel, and zinc, oil and grease, total suspended solids, and oH
are regulated. *
429
-------
Total suspended solids, in addition to being present at high con-
centrations in raw wastewater from copper forming operations, are
an important control parameter for metals removal in chemical
precipitation and sedimentation treatment systems. The metals
are precipitated as insoluble metal hydroxides, and effective
solids removal is required in order to ensure reduced levels of
toxic metals in the treatment system effluent. Total suspended
solids are also regulated as a conventional pollutant to be
removed from the wastewater prior to discharge.
Oil and grease is found at elevated concentrations in waste
streams associated with lubrication and cooling, and alkaline
cleaning, as well as heat treatment when oil is used as the heat
treating medium. Generally the compounds measured by the
analytical procedure for determining oil and grease are removed
in skimming operations. When emulsions are used for lubrication
it may be necessary to apply chemical emulsion breaking
technology prior to oil skimming.
The importance of pH control for environmental reasons is docu-
mented in Section VI (p. 228), and its importance in metals
removal technology is documented in Section VII (p. 243). Even
small excursions from the optimum pH level can result in less
than optimum functioning of the system and inability to achieve
specified results. The optimum operating level is usually found
to be pH 8.7 to 9.3. To allow a reasonable operating margin
above this level and preclude the need for final pH adjustment,
the effluent pH is specified to be within the range of 7.5 to 10
rather than the more common 6.0 to 9.0.
Hexavalent chromium and trivalent chromium, the two common
valence states of chromium, comprise the total chromium para-
meter. Hexavalent chromium is found at high concentrations in
wastewaters from pickling operations using sodium dichromate.
Because chemical precipitation and settling only controls the
trivalent form of chromium, the BPT model treatment technology
also includes chemical reduction of chromium. As a result,
although hexavalent chromium is not specifically regulated, it
will be adequately controlled by the limitation on total
chromium.
The toxic metals copper, lead, nickel, and zinc are regulated
under BPT since they are present in the wastewater in significant
concentrations from a large number of plants. As discussed in
Section III (p. 54), lead, nickel, and zinc are used as alloying
agents. Other toxic metals may be present in copper forming
wastewaters when used as alloying additives or found as contami-
nants in copper and copper alloys. These metals, which include
antimony, arsenic, beryllium, cadmium, silver, and selenium will
430
-------
be adequately controlled when the regulated metals are treated to
the levels achievable by the model treatment technology.
DISCHARGE FLOWS
The BPT regulatory flows for the copper forming waste streams are
presented in Table IX-1. The flows are expressed as liters per
off metric ton of production (1/kkg). A discussion of how each
of these flows was determined is presented below.
The flows which are used to calculate mass limitations and stan-
dards based on Option 1 technology were derived in the following
manner. EPA examined the reported discharge flows for each oper-
ation, and then averaged the flows from plants demonstrating
water use practices consistent with the majority of plants. In
some instances, flows are based on in-process control when these
controls are common industry practice.
Hot Rolling Spent Lubricant. The production normalized flow data
for hot rolling spent lubricants are presented in Table V-2 (p.
90). Twenty-one plants reported information regarding wastewater
discharge flows from hot rolling. Of the 21 plants, four
reported no discharge from this operation and the remaining 17
reported discharges. Nine of the 17 reported recycle. The
regulatory flow is based on the average of nine plants which
reported recycle. Based on the magnitude of the reported
discharge flow rates, the Agency believes that other plants
practice recycle or some other method of flow reduction; however,
we did not include these plants in the average because the plants
did not specifically report recycle. Of the 21 plants which
submitted discharge information for hot rolling spent lubricant,
15 are presently at or below the BPT regulatory flow. The BPT
flow is 103 1/kkg.
Cold Rolling Spent Lubricant. The production normalized flow
data for cold rolling spent lubricant are presented in Table V-3
{p. 91). The BPT flow allowance of 379 1/kkg is based on the
average discharge flow rate of all 28 plants which reported a
discharge.
Drawing Spent Lubricant. The production normalized flow data for
drawing spent lubricant are presented in Table V-4 (p. 92). Of
the 85 plants which have drawing operations, 63 currently
achieve zero discharge through extensive recycling and contract
hauling. However, zero discharge for this stream based on
contract hauling may not provide any environmental benefit.
Contract haulers merely transfer the waste to a waste treatment
facility or an oil reclaimer who in turn processes the waste by
recovering the oil component and discharging the water fraction
either with or without treatment. The model treatment
431
-------
technologies used to establish BPT limits would effectively treat
drawing spent lubricants.
Therefore, the Agency has decided to establish a flow allowance
for this waste stream of 85 1/kkg, which is the average discharge
reported by the 22 plants that discharge spent drawing lubricant.
These plants routinely recirculated the lubricant as much as
possible before discharging it, usually 95 to 99 percent. The
flow allowance applies only to those drawers who treat their
spent drawing lubricant and discharge the treated effluent at the
copper forming site.
Solution Heat Treatment Contact Cooling Water. The production
normalized flow data for solution heat treatment are presented in
Table V-5 (p. 95). A review of these data revealed that the
amount of water used and discharged does not vary significantly
as a function of which major forming operation it follows. The
BPT flow allowance is based on the average discharge flow rate of
the 21 plants which reported a discharge of solution heat
treatment wastewater. While three other plants reported zero
discharge, the Agency believes that plants have to discharge a
portion of the recirculating flow to prevent the buildup of
dissolved solids. Therefore, these plants were not included in
the average. The resulting flow allowance is 2,541 1/kkg.
Extrusion Press Solution Heat Treatment. The production
normalized flow data for extrusion press solution heat treatment
are presented in Table V-6 (p. 96). The BPT flow allowance of
2.00 1/kkg is based on the average discharge flow rate of the
three plants which reported a discharge of extrusion press
solution heat treatment wastewater.
Alkaline Cleaning Bath. The production normalized flow data for
alkaline cleaning bath wastewater are presented in Table V-7 (p.
97). The BPT flow allowance of 46.7 1/kkg is based on the
smaller of the two discharge flows reported. The larger reported
flow (2,790 1/kkg) was not averaged because it is believed to
be incorrectly reported. This f.low was reported by a plant with
a very small production of approximately 10 tons per year of
copper tubing. This plant does not report rinsing following
alkaline cleaning and therefore is probably showing a flow for
both the bath and rinse streams.
Alkaline Cleaning Rinse. The production normalized flow data for
alkaline cleaning rinses are presented in Table V-8 (p. 98).
Only one plant reported recycle of alkaline cleaning rinse water.
The BPT flow allowance of 4,214 1/kkg is based on the average
flow of all five plants which reported a discharge of alkaline
cleaning rinse wastewater. The plant practicing recycle was
432
-------
included in the average because flow was not significantly
different from flows from plants without recycle.
Alkaline Cleaning Rinse for Forged Parts. The BPT flow allowance
of 12,642 1/kkg is based on the production normalized flow of the
one plant reporting a discharge of this waste stream for forged
parts. A separate flow allowance for alkaline cleaning rinse for
forged parts is established because rinsing of forged parts
requires a greater amount of water than rinsing of other parts.
Annealing with Water. The production normalized flow data for
annealing water are presented in Table V-9 (p. 99). Twenty-two
of the 33 plants using annealing water reported a discharge.
Eleven plants reported zero discharge of annealing water;
however, they generally achieve zero discharge through natural
evaporation or land application. Natural evaporation and land
application is not available to all plants. The Agency believes
that a periodic discharge from this waste is necessary to control
levels of dissolved solids. Therefore, the BPT flow allowance is
based on the average flow of all plants which reported a
discharge. The BPT flow allowance is 5,667 1/kkg.
Annealing with Oil. The production normalized flow data for
annealing oil are presented in Table V-10 (p. 101). Zero
discharge is typically achieved through contract hauling of the
relatively small quantities of annealing oil which are
periodically dumped. There are no direct dischargers of
annealing oil.
Pickling Bath. The production normalized flow data for pickling
baths are presented in Table V-ll (p. 102). The BPT flow
allowance of 116 1/kkg is based on the average flow of the 11
plants which reported discharges from pickling baths.
Pickling Rinse. The production normalized flow data for pickling
rinses are presented in Table V-12 (p. 103). The reported values
ranged from 65.58 to 257,000 1/kkg. Two plants reported
production normalized flows approximately four times higher than
any other reported values. The BPT flow allowance of 3,622 1/kkg
is based on the median flow of all 40 plants which reported
pickling rinse discharges. The median was used rather than the
average to lessen the influence of the two extreme values.
Pickling Rinse of Forged Parts. The BPT flow allowance for
pickling rinse for forged parts is established as 3,918 1/kkg.
This is based on data from two forging plants that provided data
on rinsing of forged parts (see Table V-14, p. 106). Other
forging plants that reported rinsing flows did not practice
recirculation or recirculated spray rinsing. Recirculated spray
rinsing is more efficient than non-recirculated spray rinsing and
433
-------
is as efficient as the cascade rinsing reported. Recirculated
spray rinsing is widely demonstrated on other pickling rinses
within the category. Therefore, spray rinsing is the technology
basis for the BPT flow and space constraints do not apply because
additional tankage above presently available tankage is not
required.
Pickling Fume Scrubbers. The production normalized flow data for
pickling fume scrubbers are presented in Table V-13 (p. 105).
The BPT flow allowance of 626 1/kkg is based on the average flow
from two of the three plants which reported pickling fume
scrubbers. The third and highest value was not included in the
average because the Agency believes that it was incorrectly
reported.
Tumbling or Burnishing. A regulatory flow allowance of 583 1/kkg
is being established for the tumbling or burnishing waste stream.
This allowance is based on the one plant that reported a
discharge of this stream.
Surface Coating (Hot Coating). A surface coating operation may
have any of the following wastewater sources associated with it:
emission scrubbing water, the liquid flux bath, and the spent
abrasive. The Agency was unable to obtain enough flow data for
these sources to justify establishing a separate flow allowance
for each of the sources; the flow data that the Agency was able
to obtain was reported for the surface coating operation as a
whole. Therefore, the Agency is setting one flow allowance for
the surface coating waste stream. This flow allowance of 743
1/kkg is based on the data obtained from the one plant reporting
a discharge from this stream. Direct process wastewater and fume
scrubber blowdown are included in this allowance.
Miscellaneous Waste Streams. Miscellaneous waste streams include
hydrotesting, sawing, surface milling, and maintenance. Three
plants each submitted flow and production data on hydrotesting,
sawing, and maintenance, respectively. It is believed that
surface milling requires the same amount of process water as
sawing because the operations are similar and water is used in
both operations for lubrication and cooling. The sum of the
production normalized flows for these four streams is 22.3 1/kkg,
which has been established as the regulatory flow for
miscellaneous waste streams.
Plants discharging greater than regulatory flows for a given
stream may have to reduce their discharge rate for that process.
Alternatively, in that plants are only required to comply with a
total discharge mass based limit, plants have the option of sub-
stantially reducing their water discharges from other process
operations by any means. Information from plant visits shows
434
-------
that many plants with large flows use water based on historical
considerations without regard for actual process requirements.
Consequently, the Agency believes that plants can achieve the BPT
regulatory flows without engineering modifications and therefore
should not incur significant costs.
WASTEWATER TREATMENT TRAIN
Option 1 discussed in Section X on page 451 represents the
average of the best existing performance of pollution control
technology currently used by copper forming plants. There are 36
plants in the copper forming category that use hydroxide
precipitation and sedimentation. Twenty-five of these plants are
direct dischargers. There are ten plants that use oil skimming
and eight plants that practice hexavalent chromium reduction as
preliminary treatment prior to chemical precipitation and
sedimentation. Spray rinsing of pickled forged parts is
demonstrated in two plants. Recycle of hot rolling spent
lubricant is demonstrated in at least 13 plants in the category.
The BPT treatment train consists of chemical precipitation and
sedimentation and preliminary treatment, where necessary, con-
sisting of chemical emulsion breaking, oil skimming, and hexa-
valent chromium reduction. The effluent from preliminary treat-
ment is combined with other wastewaters for common treatment by
chemical precipitation and sedimentation. The hot rolling spent
lubricant, cold rolling spent lubricant, annealing oil, extrusion
press heat treatment, alkaline cleaning bath, alkaline cleaning
rinse, alkaline cleaning rinse for forged parts, solution heat
treatment, drawing spent lubricant, tumbling or burnishing, sur-
face coating, and maintenance waste streams may require chemical
emulsion breaking and oil skimming prior to combined treatment.
The pickling bath and rinse and pickling rinse for forged parts
waste streams may require hexavalent chromium treatment prior to
combined treatment. The pickling fume scrubber and annealing
water waste streams generally will not require any preliminary
treatment. This treatment train is presented in Figure IX-1.
EFFLUENT LIMITATIONS
The effluent concentrations resulting from the application of the
BPT technology are identical for all wastewater streams; however,
the mass limitations vary for each waste stream depending on the
regulatory flow. The effluent concentrations which were used as
the basis for BPT mass limitations are presented in Table VII-20,
p. 336, and the regulatory flows are summarized in Table IX-1, p.
437.
The treatment performance data discussed in Section VII are used
to obtain maximum daily and monthly average pollutant concentra-
435
-------
tions. .These concentrations (mg/1) along with the copper forming
regulatory flows (1/kkg of copper processed) are used to obtain
the maximum daily and monthly average values (mg/kg) for effluent
limitations and standards. The monthly average values are based
on the average of 10 consecutive sampling days. The 10 day aver-
age value was selected as the minimum number of consecutive sam-
ples which need to be averaged to arrive at a stable slope on a
statistically based curve relating one day and 30 day average
values, and it approximates the most frequent monitoring require-
ment of direct discharge permits. The monthly average numbers
shown in the regulation are to be used by permit writers in
writing direct discharge permits.
Effluent limitations representing the degree of effluent reduc-
tion attainable by the application of the best practicable con-
trol technology currently available (BPT) are shown in Tables IX-
1 through IX-8.
COMPLIANCE COSTS AND ENVIRONMENTAL BENEFITS
In establishing BPT, EPA considered the cost of treatment and
control in relation to the effluent reduction benefits. BPT will
remove 27,000 kilograms of toxic pollutants (metals and organics)
and 56,000 kilograms of conventional and nonconventional pollu-
tants per year beyond current discharge levels. The estimated
capital investment cost to comply with BPT is $6.4 million (1982
dollars), with a total annual cost of $6.6 million. The Agency
has determined that the effluent reduction benefits justify the
cost of complying with this regulation.
436
-------
Table IX-1
BAT REGULATORY FLOWS FOR COPPER FORMING WASTE STREAMS
Waste Stream BAT Flow (1/kkg)
Hot Rolling Spent Lubricant 103
Cold Rolling Spent Lubricant 379
Drawing Spent Lubricant 85
Annealing Water 5,667
Annealing Oil 0
Solution Heat Treatment 2,541
Extrusion Press. Heat Treatment 2
Pickling Fume Scrubber 626
Pickling Bath 116
Alkaline Bath 46.7
Pickling Rinse (Forged Parts) 3,918
Pickling Rinse (All Other Parts) 3,622
Alkaline Rinse (Forged Parts) 12,642
Alkaline Rinse (All Other Parts) 4,214
Tumbling or Burnishing 583
Surface Coating 743
Miscellaneous Waste Streams 22.3
437
-------
Table IX-2
BPT FOR HOT ROLLING SPENT LUBRICANT
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy hot rolled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy hot rolled
Chromium 0.045 0.018
Copper 0.195 0.103
Lead 0.015 0.013
Nickel 0.197 0.130
Zinc 0.150 0.062
Oil and Grease 2.060 1.236
TSS 4.223 2.008
pH (1) (T)
'Within the range of 7.5 to 10.0 at all times.
Table IX-3
BPT FOR COLD ROLLING SPENT LUBRICANT
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy cold rolled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy cold rolled
Chromium 0.166 0.068
Copper 0.720 0.379
Lead 0.056 0.049
Nickel 0.727 0.481
Zinc 0.553 0.231
Oil and Grease 7.580 4.548
TSS 15.539 7.390
PH (T) (1)
^Within the range of 7.5 to 10.0 at all times.
438
-------
Table IX-4
BPT FOR DRAWING SPENT LUBRICANT1
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy drawn
English Units - lb/1,000,000 off-lbs of copper or copper
alloy drawn
Chromium 0.037 0.015
Copper 0.161 0.085
Lead 0.012 0.011
Nickel 0.163 0.107
Zinc 0.124 0.051
Oil and Grease 1.700 1.020
TSS 3.485 1.657
pH (2) (2)
'Applicable only to drawers who treat and discharge spent
drawing lubricants.
2Within the range of 7.5 to 10.0 at all times.
Table IX-5
BPT FOR SOLUTION HEAT TREATMENT
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy heat treated
English Units - lb/1,000,000 off-lbs of copper or copper
alloy heat treated
Chromium 1.118 0.457
Copper 4.827 2.541
Lead 0.381 0.330
Nickel 4.878 3.227
Zinc 3.709 1.550
Oil and Grease 50.820 30.492
TSS 104.181 49.549
pH (2) (2)
^Within the range of 7.5 to 10.0 at all times.
439
-------
Table IX-6
BPT FOR EXTRUSION HEAT TREATMENT
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy heat treated on an extrusion press
English Units - lb/1,000,000 off-lbs of copper or copper
alloy heat treated on an extrusion press
Chromium
Copper
Lead
Nickel
Zinc
Oil and Grease
TSS
pH
0.00088
0.003
0.0003
0.003
0.002
0.040
0.082
0.00036
0.002
0.00026
0.002
0.001
0.024
.039
f" V. /
^Within the range of 7.5 to 10.0 at all times.
Table IX-7
BPT FOR ANNEALING WITH WATER
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy annealed
with water
English Units - lb/1,000,000 off-lbs of copper or copper
alloy annealed with water
Chromium
Copper
Lead
Nickel
Zinc
Oil and Grease
TSS
pH
2
10
0
10
8
113
493
767
850
880
273
340
232.347
1.020
5.667
0.736
7.197
3.456
68.004
110.506
'Within the range of 7.5 to 10.0 at all times
440
-------
Table IX-8
BPT FOR ANNEALING WITH OIL
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy annealed
with oil
English Units - lb/1,000,000 off-lbs of copper or copper
alloy annealed with oil
Chromium 0 0
Copper 0 °
Lead 0 0
Nickel 0 0
Zinc 00
Oil and Grease 0 0
TSS 0 0
pH (1) C1)
1Within the range of 7.5 to 10.0 at all times.
Table IX-9
BPT FOR ALKALINE CLEANING RINSE
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy alkaline cleaned
Chromium 1.854 0.758
Copper 8.006 4.214
Lead 0.632 0.547
Nickel 8.090 5.351
Zinc 6.152 2.570
Oil and Grease 84.280 50.568
TSS 172.774 82.173
pH (T) (T)
1Within the range of 7.5 to 10.0 at all times.
441
-------
Table IX-10
BPT FOR ALKALINE CLEANING RINSE FOR FORGED PARTS
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
forged parts alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy forged parts alkaline cleaned
Chromium 5.562 2.275
Copper 24.019 12.642
Lead 1.896 1.643
Nickel 24.272 16.055
Zinc 18.457 7.711
Oil and Grease 252.840 151.704
TSS 518.322 246.519
pH (I) C1)
1Within the range of 7.5 to 10.0 at all times.
Table IX-11
BPT FOR ALKALINE CLEANING BATH
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy alkaline cleaned
Chromium 0.020 0.0084
Copper 0.089 0.046
Lead 0.0070 0.0060
Nickel 0.089 0.059
Zinc 0.068 0.028
Oil and Grease 0.93 0.56
TSS 1.91 0.91
pH (1)
Within the range of 7.5 to 10.0 at all times.
442
-------
Table IX-12
BPT FOR PICKLING RINSE
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled
Chromium 1.593 0.651
Copper 6.881 3.622
Lead 0.543 0.470
Nickel 6,954 4.599
Zinc 5.288 2.209
Oil and Grease 72.440 43.464
TSS 148.502 70.629
pH (T) (T)
^Within the range of 7.5 to 10.0 at all times.
Table IX-13
BPT FOR PICKLING RINSE FOR FORGED PARTS
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
forged parts pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy forged parts pickled
Chromium 1.723 0.705
Copper 7.444 3.918
Lead 0.587 0.509
Nickel 7.522 4.975
Zinc 5.720 2.389
Oil and Grease 78.360 47.016
TSS 160.638 76.401
^Within the range of 7.5 to 10.0 at all times.
443
-------
Table IX-14
BPT FOR PICKLING BATH
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled
Chromium 0.051 0.020
Copper 0.220 0.116
Lead 0.017 0.015
Nickel 0.222 0.147
Zinc 0.169 0.070
Oil and Grease 2.320 1.392
TSS 4.756 2.262
pH C1) C1)
1 Within the range of 7.5 to 10.0 at all times.
Table IX-15
BPT FOR PICKLING FUME SCRUBBER
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled
Chromium 0.275 0.112
Copper 1.189 0.626
Lead 0.093 0.081
Nickel 1.201 0.795
Zinc 0.913 0.381
Oil and Grease 12.520 7.512
TSS 25.666 12.207
PH (T) (1)
^Within the range of 7.5 to 10.0 at all times.
444
-------
Table IX-16
BPT FOR TUMBLING OR BURNISHING
Maximum
For Any Maximum for
Pollutant or Pollutant Property _ One Day _ Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
tumbled or burnished
English Units - lb/1,000,000 off-lbs of copper or copper
alloy tumbled or burnished
Chromium 0, 256 0. 1 04
Copper 1.107 0.583
Lead 0.087 0.075
Nickel 1.119 0.740
Zinc 0.851 0.355
Oil and Grease 11.660 6.996
TSS 23.903 11.368
1Within the range of 7.5 to 10.0 at all times.
Table IX-1 7
BPT FOR SURFACE COATING
Maximum
For Any Maximum for
Pollutant or Pollutant Property _ One Day _ Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
surface coated
English Units - lb/1,000,000 off-lbs of copper or copper
alloy surface coated
Chromium 0.326 0.133
Copper 1.411 0.743
Lead 0.111 0.096
Nickel 1.426 0.943
Zinc 1.084 0.453
Oil and Grease 14.680 8.916
TSS 30.463 14.488
PH (T) (1)
^Within the range of 7.5 to 10.0 at all times.
445
-------
Table IX-13
BPt FOR MISCELLANEOUS WASTE STREAMS
Maximum
For Any Maximum for
Pollutant ot Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy formed
English Units - lb/1,000,000 off-lbs of copper or copper
alloy formed
Chromium 0.009 0.003
Copper 0.041 0.021
Lead 0.003 0.002
Nickel 0.041 0.027
Zinc 0.031 0.013
Oil and Grease 0.436 0.261
TSS 0.893 0.425
pH (T)
1Within the range of 7.5 to 10.0 at all times.
446
-------
447
-------
-------
SECTION X
BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE
The factors considered in assessing best available technology
economically achievable (BAT) include the age of equipment and
facilities involved, the process employed, process changes, non-
water quality environmental impacts (including energy require-
ments) and the costs of application of such technology (Section
304(b)(2)(B)). In general, the BAT technology level represents/
at a minimum, the best existing economically achievable perfor-
mance of plants of various ages, sizes, processes or other shared
characteristics. As with BPT, in those categories where existing
performance is universally inadequate, BAT may be transferred
from a different subcategory or category. BAT may include pro-
cess changes or internal controls, even when not common industry
practice.
TECHNICAL APPROACH TO BAT
The Agency reviewed a wide range of technology options and evalu-
ated the available possibilities to ensure that the most effec-
tive and beneficial technologies were used as the basis of BAT.
To accomplish this, the Agency elected to examine technology
alternatives which could be applied to copper forming as BAT
options and which would represent substantial progress toward
prevention of polluting the environment above and beyond progress
achievable by BPT. The statutory assessment of BAT considers
costs, but does not require a balancing of costs against effluent
reduction benefits see [Weyerhaeuser v. Costle, 11 ERC 2149 (D.C.
Cir. 1978)]; however, in assessing the proposed BAT, the Agency
has given substantial weight to the reasonableness of costs.
At proposal, we evaluated five BAT options. Option 1 is the
recommended BPT treatment. Option 2 is the recommended BPT
treatmentplusflow reduction. Option 3 provides additional
treatment by including end-of-pipe filtration technology, and
Option 4 is Option 3 plus additional flow reduction of pickling
rinsewater through the use of countercurrent cascade rinsing.
Option 5 adds filtration as an end-of-pipe treatment process to
Option 1 which does not include flow reduction. Each treatment
technology option is based on common frreqt*»ent of all waste
streams and results in the same concentrations of pollutants in
the effluent regardless of the number and combinations of copper
forming waste streams entering the treatment system. Mass limi-
tations derived from these options may vary because of the impact
of different regulatory flows. The derivation of these regula-
tory flows is discussed later in this section.
I
z
449
-------
In summary form, the treatment technologies considered for BAT
for copper forming are:
Option T (Figure X-l) based on:
Lime and settle (chemical precipitation of metals,
followed by sedimentation), and where required
Chemical emulsion breaking,
Oil skimming,
Chemical reduction of hexavalent chromium, and
Spray rinsing and recirculation of the pickling rinse
stream for forged parts, and
Recycle of hot rolling lubricant.
This option is equivalent to the technologies on which BPT limi-
tations are based.
Option 2 (Figure X-2) based on:
Option 1, plus process wastewater flow reduction by the
following methods:
Recycle of solution heat treatment contact cooling
water.
Recycle of annealing contact cooling water, and
Spray rinsing and recirculation of the pickling
rinse stream for all pickling operations.
This option is equivalent to the technology on which BAT limita-
tions are based.
Option 3 (Figure X-3) based on:
Option 2, plus polishing filtration (multimedia).
Option 4 (Figure X-4) based on:
Option 3, plus further reduction of flow through the use of
countercurrent cascade rinsing on the pickling rinse stream.
Option 5 (Figure X-5) based on:
*
Option 1, plus polishing filtration (multimedia).
.' *
450
-------
The Agency considered but ultimately rejected thermal emulsion
breaking as a treatment component of BAT. Thermal emulsion
breaking is practiced at six copper forming plants. This process
removes water from oil emulsions, allowing the water to be reused
and the oil to be reused or disposed of efficiently, usually by
contract hauling. Thermal emulsion breaking has high energy
requirements and, with the rapid escalation of energy costs over
the last decade, is a high cost technology. EPA did not include
thermal emulsion breaking as part of the BAT model technology
because plants using chemical emulsion breaking in combination
with oil skimming will achieve the same level of oil removal as
plants using thermal emulsion breaking. Most copper forming
plants will use chemical emulsion breaking because it will be
less expensive than thermal emulsion breaking; however, plants
with waste heat available may want to use thermal emulsion
breaking to achieve the BPT oil and grease limitation.
OPTION 1
Option i represents the BPT end-of-pipe treatment technology.
This treatment train consists of preliminary treatment, when
necessary, of chemical emulsion breaking and oil skimming, and
hexavalent chromium reduction. The effluent from preliminary
treatment is combined with other wastewaters for common treatment
by lime and settle. Option 1 is also based on spray rinsing and
recirculation of the pickling rinse stream for forged parts.
OPTION 2
Option 2 builds upon the BPT end-of-pipe treatment technologies
of skimming, lime and settle with preliminary treatment to reduce
nexavalent chromium and chemically break emulsions. Flow reduc-
tion measures, based on in-process changes, are the mechanisms
tor reducing pollutant discharges at Option 2. The flow reduc-
tion measures concentrate the pollutants present in these waste
streams. Treatment of a more concentrated stream allows a
greater net removal of pollutants and economies of treating a
reduced flow. The methods for reducing process wastewater gener-
ation include recycle of solution heat treatment contact cooling
water and annealing contact cooling water through cooling towers
and recirculation. Spray rinsing and recirculation of the rinse-
water is the method for reducing wastewater discharges from the
pickling rinse waste stream. These in-plant control measures
were discussed in detail in Section VII (p. 307).
OPTION 3
Option 3 builds upon the technical basis of Option 2 by adding
conventional multimedia filtration after the Option 2 treatment
451
-------
train and the in-process flow reduction controls. Gravity,
mixed-media filtration was used as the technical basis for
establishing treatment performance of filtration in Section VII
(p. 273). EPA believes that other filtration technologies such
as pressure filtration are equally applicable.
OPTION 4
Option 4 builds upon the technologies established for Option 3 by
adding another in-process flow reduction control, countercurrent
cascade rinsing for the pickling rinse waste stream.
OPTION 5
Option 5 builds upon the technical basis of Option 1 by adding
conventional multimedia filtration after the Option 1 treatment
train.
BAT OPTION SELECTION
For BAT, EPA is promulgating limitations based on Option 2.
Option 2 treatment technology will result in substantial
reduction of toxic pollutants above the removal achievable by
BPT. This technology option is comprised of Option 1 (BPT) plus
flow reduction. Flow reduction consists of recycle of the
annealing water and solution heat treatment streams, and spray
rinsing and recirculation of all pickling rinse water. End-of-
pipe treatment in this technology is equivalent to Option 1,
which consists of chemical precipitation and sedimentation and,
where required, chemical emulsion breaking, oil skimming, and
hexavalent chromium reduction. All wastes are treated centrally.
The recommended BAT treatment achieves the concentrations
discussed in Section VII (p. 263). These concentrations, called
treatment effectiveness values for lime and settle, are the same
for both BPT and BAT. The incremental pollutant removal brought
about by BAT results solely from in-process flow reduction. Flow
reduction results in greater removal of pollutants because the
lower volume of wastewater discharge at BAT contains the same
concentrations of pollutants as the higher volume discharged at
BPT. The discharge flows and the rationale for the selection of
these flows are presented in a later subsection, entitled
Discharge Flows (p. 453).
The Agency has decided not to include filtration as part of the
model BAT technology. Of the 8,000 kg/yr of toxic pollutants
discharged after BPT, BAT model treatment technology is estimated
to remove 4,000 kg/yr of toxic pollutants or a total removal of
89 percent of the total current discharge. The addition of fil-
tration would remove approximately 5,000 kg/yr of toxic pollu-
tants discharged after BPT or a total removal of 91 percent of
452
-------
the total current discharge. This equates to an additional
removal of approximately 0.1 kg of toxic pollutants per day per
discharger. The incremental costs of these effluent reductions
are $1 4 million in capital cost and $1.1 million in total annual
°?? * u dir*ct dischargers. The Agency believes that given
all of these factors, the costs involved do not warrant selection
of filtration as a part of the BAT model treatment technology.
The Agency has decided to reject Option 4, which is based on the
installation of countercurrent cascade rinsing for pickling
because it is only demonstrated at four copper forming plants and
because most of the other existing plants lack sufficient space
to add the additional rinse tank and associated piping necessarv
for countercurrent cascade rinsing.
The Agency has decided to reject Option 5, which is based on
nitration added to Option 1 because it provides only one-fourth
as much pollutant removal as Option 2 at approximately the same
costs.
REGULATED POLLUTANT PARAMETERS
In implementing the terms of the Settlement Agreement in NRDC v
SE|in, 8 ERC 2120 (D.D.C. 1976); modified, 12 ERC 1833 T^D.C
?Z?«v a?u i? accordance with 33 U.S.C. 1314(b)(2)(A and B)
(1976), the Agency places particular emphasis on the toxic
pollutants. The raw wastewater concentrations from the
individual operations and the category as a whole were examined
to select those pollutant parameters found at frequencies and
concentrations warranting regulation.
The toxic metals regulated are chromium, copper, lead, nickel and
zinc. Six toxic metals, antimony, arsenic, beryllium, cadmium,
silver, and selenium, which are not specifically regulated will
be adequately controlled when the regulated metals are treated to
the levels achievable by the model treatment technology. The
toxic organics selected for regulation in Section VI are not
specifically regulated at BAT because the oil and grease limita-
tion at BPT will provide effective removal. Refer to Section VII
2'i.u 5i' ?or an exPan<*ed discussion of the removal effectiveness
S KI WT?*J£ organics with the application of oil skimming. (See
Table VII-10 and Figure VII-9, pp. 326 and 352).
DISCHARGE FLOWS
EPA studied each of the waste streams to assess the potential for
flow reduction at BAT by using the information provided in the
dcp and by observing examples of flow reduction during the sam-
pling trips. Flow reduction techniques demonstrated in this
category include recycle of solution heat treatment contact
453
-------
cooling water and annealing contact cooling water through cooling
towers, spray ringing of recirculated rinse water, and counter-
current cascade rinsing. Spray rinsing is practiced on pickling
lines in 16 plants and likewise four plants use countercurrent
rinsing.
In the case of pickling and alkaline cleaning rinse allowances
for forged parts, the Agency considered countercurrent rinsing
for additional flow reduction beyond the BPT basis of spray rins-
ing. However, as at proposal, it was determined that most exist-
ing plants that perform forging operations do not have sufficient
space to install the tanks required for countercurrent rinsing.
Therefore, the BAT regulatory flow allowances for these two
streams are equivalent to those provided at BPT. In the case of
drawing spent lubricant, the BPT regulatory flow allowance is
based on extensive recycle; the Agency has no data available to
support flow reduction for this stream beyond that required at
BPT. Tumbling or burnishing, surface coating, and miscellanoues
waste stream allowances are based on current reported industry
practice and do not require in-process flow reduction controls.
These streams have extremely low flows and will only increase BAT
pollutant discharges above proposed levels by less than two per-
cent. Accordingly, further flow reduction would not have a
significant impact on pollutant removal.
Therefore, the BAT regulatory flow allowances are equal to the
BPT flow allowances for all of the copper forming waste streams
except solution heat treatment, annealing water, and pickling
rinse. The BAT flow allowances for these three streams are pre-
sented in Table X-l. A discussion of how each of these three
flows was determined follows.
Solution Heat Treatment. The production normalized flow data for
solution heat treatment are presented in Table V-5 (p. 95).
Recycle is practiced by eight of the 24 plants which reported
solution heat treatment. The reported recycle rates range from
85 percent to 100 percent. The plants currently recycling this
water are using cooling towers to remove excess heat. Although
three plants reported no discharge of wastewater from solution
heat treatment, the Agency believes that most plants have to
discharge a portion of the recirculating flow to prevent the
buildup of dissolved solids. Consequently, these three plants
were not used to obtain the average. The Agency based the BAT
regulatory flow allowance of 646 1/kkg on the average of the
flows reported by the five plants which not only practice recycle
but also reported discharge flow rates.
Annealing with Water. The production normalized flow data for
annealing water are presented in Table V-9 (p. 99). Eleven
plants reported zero discharge of annealing water. The Agency
454
-------
did not select zero discharge for BAT because they generally
achieve zero discharge through natural evaporation or land
application. This disposal method requires large amounts of land
and is not feasible for most existing plants. Six of the 22
plants which discharge annealing water practice recycle. The
reported recycle rates for these six plants range from 50 percent
to 98 percent. Plants recycling this water do so in the same
manner as plants recycling solution heat treatment water. As
such, EPA based the regulatory flow allowance of 1,240 1/kkg on
the average flow reported by the six discharging plants which
practice recycle.
Pickling Rinse. The production normalized flow data for pickling
rinses are presented in Table V-12 (p. 103). Sixteen of the 42
plants reporting pickling rinse water use spray rinsing. Five
other plants did not indicate in the dcp that spray rinsing was
used, but based on the reported discharge flow rates the Agency
believes that these plants are using spray rinsing or an
equivalent flow reduction technique to attain these flows. EPA
based the BAT regulatory flow on the average of the 21 plants
which represent the lower fifthieth percentile of the reported
production normalized flows. The BAT regulatory flow is 1,300
1/kkg.
WASTEWATER TREATMENT TRAIN
EPA has selected Option 2 as the basis for BAT in this category.
Again, this option uses the same technology as BPT, with the
addition of measures to reduce the flows from selected waste
streams. The end-of-pipe treatment configuration is shown in
Figure X-2. The combination of in-process control and treatment
technology significantly increases the removals of pollutants
over that achieved by BPT.
EFFLUENT LIMITATIONS
Table VII-20 (p. 336) presents the treatment effectiveness
corresponding to the BAT treatment train for the pollutants
selected. Effluent concentrations (one day maximum and ten day
average values) are multiplied by the regulatory discharge flows
summarized in Table X-l to calculate the mass of pollutants
allowed to be discharged per mass of product. The results of
these calculations are shown in Table X-2 through X-8.
COMPLIANCE COSTS AND ENVIRONMENTAL BENEFITS
In establishing BAT, EPA considered the cost of treatment and
control in relation to the effluent reduction benefits. The
application of the proposed BAT will remove 31,000 kilograms per
year of toxic pollutants (metals and organics) from current dis-
455
-------
charge levels. The estimated capital investment cost is $6.5
million (1982 dollars) for equipment and in-process changes not
presently in place and a total annual cost of $6.3 million for
all equipment and in-process changes.
The incremental effluent reduction benefits of BAT above BPT are
the removal annually of 4,000 kg of toxic pollutants. The incre-
mental costs of these benefits are $0.10 million capital cost;
there are no additional annual costs required. Thus, we conclude
that the costs to achieve the effluent reduction benefits associ-
ated with the BAT limitations are economically achievable.
456
-------
Table X-1
BAT REGULATORY FLOWS FOR COPPER FORMING WASTE STREAMS
Waste Stream BAT Flow (1/kkg)
Hot Rolling Spent Lubricant 103
Cold Rolling Spent Lubricant 379
Drawing Spent Lubricant 85
Annealing Water 1,240
Annealing Oil 0
Solution Heat Treatment 646
Extrusion Press Heat Treatment 2
Pickling Fume Scrubber 626
Pickling Bath 116
Alkaline Bath 46.7
Pickling Rinse (Forged Parts) 3,918
Pickling Rinse (All Other Parts) 1,300
Alkaline Rinse (Forged Parts) 12,642
Alkaline Rinse (All Other Parts) 4,214
Tumbling or Burnishing 583
Surface Coating 743
Miscellaneous Waste Streams 22.3
457
-------
Table X-2
BAT FOR HOT ROLLING SPENT LUBRICANT
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy hot rolled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy hot rolled
Chromium 0.045 0.018
Copper 0.195 0.103
Lead 0.015 0.013
Nickel 0.197 0.130
Zinc 0.150 0.062
Table X-3
BAT FOR COLD ROLLING SPENT LUBRICANT
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy cold rolled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy cold rolled
Chromium 0.166 0.068
Copper 0.720 0.379
Lead 0.056 0.049
Nickel 0.727 0.481
Zinc 0.553 0.231
458
-------
Table X-4
BAT FOR DRAWING SPENT LUBRICANT1
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy drawn
English Units - lb/1,000,000 off-lbs of copper or copper
alloy drawn
Chromium 0.037 0.015
Copper 0.161 0.085
Lead 0.012 0.011
Nickel 0.163 0.107
Zinc 0.124 0.051
^Applicable only to drawers who treat and discharge spent
drawing lubricants.
Table X-5
BAT FOR SOLUTION HEAT TREATMENT
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy heat treated
English Units - lb/1,000,000 off-lbs of copper or copper
alloy heat treated
Chromium 0.284 0.116
Copper 1.227 0.646
Lead 0.096 0.083
Nickel 1.240 0.820
Zinc 0.943 0.394
459
-------
Table X-6
BAT FOR EXTRUSION HEAT TREATMENT
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy heat treated on an extrusion press
English Units - Lb/1,000,000 off-lbs of copper or copper
alloy heat treated on an extrusion press
Chromium 0.00088 0.00036
Copper 0.003 0.0020
Lead 0.0003 0.00026
Nickel 0.003 0.002
zinc 0.002 0.001
Table X-7
BAT FOR ANNEALING WITH WATER
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy annealed
with water
English Units - lb/1 f 000,000 off-lbs of copper or copper
alloy annealed with water
Chromium 0.545 °
Copper 2.356 1.240
Lead 0.186 0.161
Nickel 2.380 1.574
Zinc 1-810 0.756
460
-------
Table X-8
BAT FOR ANNEALING WITH OIL
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy annealed
with oil
English Units - lb/1,000,000 off-lbs of copper or copper
alloy annealed with oil
Chromium 0 0
Copper 0 0
Lead 0 0
Nickel 0 0
Zinc 0 0
Table X-9
BAT FOR ALKALINE CLEANING RINSE
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy alkaline cleaned
Chromium 1.854 0.758
Copper 8.006 4.214
Lead 0.632 0.547
Nickel 8.090 5.351
Zinc 6.152 2.570
461
-------
Table X-10
BAT FOR ALKALINE CLEANING RINSE FOR FORGED PARTS
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
forged parts alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy forged parts alkaline cleaned
2J'.019 12'. S3
1'896 1'643
Nickel 24'272 16'05?
fine 18.457 7.711
Table X-11
BAT FOR ALKALINE CLEANING BATH
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy alkaline cleaned
- -sis s:ss*
0.0070 o.ooeo
Nickel °-089 °'059
* 0.068 0.028
462
-------
Table X-12
BAT FOR PICKLING RINSE
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled
Chromium 0.574 0.235
Copper 2.481 1.306
Lead 0.195 0.169
Nickel 2.507 1.658
Zinc 1.906 0.796
Table X-13
BAT FOR PICKLING RINSE FOR FORGED PARTS
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
forged parts pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy forged parts pickled
Chromium 1.723 0.705
Copper 7.444 3.918
Lead 0.587 0.509
Nickel 7.522 4.975
Zinc 5.720 2.389
463
-------
Table X-14
BAT FOR PICKLING BATH
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled
Chromium 0.051 0.020
Copper 0.220 0.116
Lead 0.017 0.015
Nickel 0.222 0.147
Zinc 0.169 0.070
Table X-15
BAT FOR PICKLING FUME SCRUBBER
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1 ,000,000 off-lbs of copper or copper
alloy pickled
Chromium 0.275 0.112
Copper 1.189 0.626
Lead 0.093 0.081
Nickel 1.201 0.795
Zinc 0.913 0.381
464
-------
Table X-16
BAT FOR TUMBLING OR BURNISHING
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
tumbled or burnished
English Units - lb/1,000/000 off-lbs of copper or copper
alloy tumbled or burnished
Chromium 0.256 0.104
Copper 1.107 0.583
Lead 0.087 0.075
Nickel 1.119 0.740
Zinc 0.851 0.355
Table X-17
BAT FOR SURFACE COATING
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
surface coated
English Units - lb/1,000,000 off-lbs of copper or copper
alloy surface coated
Chromium 0.326 0.133
Copper 1.411 0.743
Lead 0.111 0.096
Nickel 1.426 0.943
Zinc 1.084 0.453
465
-------
Table X-18
BAT FOR MISCELLANEOUS WASTE STREAMS
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy formed
English Units - lb/1,000,000 off-lbs of copper or copper
alloy formed
Chromium 0.009 0.003
Copper 0.041 0.021
Lead 0.003 0.002
Nickel 0.041 0.027
Zinc 0.031 0.013
466
-------
H
CM
rJ
g
05
O
Z
1
w
H
t-H
CL.
w
z
tlj
CO
3
o
1— 1
15
Q
ta
oS
EH
3
^J
£-4
3
-3
-J
O
0.
NO
•* o
T—
c
0 X
4J r-
ft
O co
P-.
NO
en O
^
C
0 X
-tH
a "•
O ON
ON
NO
N O
V—
c
O X
4J •—
ft
O ON
Oi
\o
T- O
•— •
n
O X
•r*
4J CM
a
O NO
f—.
CM
01 NO
U O
CO —
at
3 X
3 o
to m
os -d-
.— s
Id
IJ »^
c --
at r-i
" 3 "*"
i-l O
O r-l
fc fa
T3
« ONCONO — mcO
Vi > -d-cM eninco m
«--. CM CM
.c ac
o -^
CO
1-4
Q
O o r-. com .—
TJ O O «— CO o ' —
01 Vi — CMOCM
> > -*CM CM
O ^** * *
£ 0£ C*J CO
flj .^ ^^
OS
•o
0) ON CO ON ON NO ON
Vi >, <3- CM -d" NO 00 r*.
«t-^ CM en
.fl OC
09
•H
a
OO >• -* — CM
o ^— -• *
E oC CM en
41 j^ ,d-
OS
i— vO ^- OO
o-d* m NO
— • «— i—
•d-COOCM
3\m eM-4-
oen m
ncM ON
4
< —
.^
DO CO ON co
•—OS NO CM
NT- CM
--NO CM en
nooeo
Den -d-
ncM ON
m.
I—
,3-
-o
4) 0v 00 CO en to O\
V ^ -^ C1*! r** GO P^ ^
cti *^ cJ 10 t~
JS M
O .M
CO
-H
a
oo-*o*o«-
•O O O I"- O r- NO
QJ i-t CN r^ i—
> > -d1.— CM
O ^^ * *
S OC CMCO
(U J^ ^J
OS
nr- — r—
no* P-CM
--CM en
>Jr--o en
NO O 00
nesi en
•d-cM ON
*
r—
•&
-o
0) CTiCOCMCMCM — WON'-'-
Vr X -^ CM in en o en
ed^. CM »-CMNO en
JC OC —
09
•p4
1=)
O O O CM ON CO
-O O O O inco -d-
11 Vl OvOCTN
^ ^ ^ O v—
O "^ * *
E OC ' CMen
01 ^ • ^
OS
ONCOCM -*CM CM
— -^ " •
of , es en
pM -d"
e c -r* e s o cx^
*-> 00 *O Vl O. W
C Vi o] J3 O o
O r-l r-l C
-1 r-
^ r—
•^- CO
n
T—
01
Vi
o n
3 0
r-l Vl
Eu M
— O
O «-
ON en
»- p-
•* m
i— •—
en CM
ON CM
A •*
COCO
o\ co
-d- m
r- o
p- «—
in ON
CM ON
oo m
en »—
NO NO
COON
. •
oo r-
ON en
-d- m
CM O
ON —
OO ON
T- ON
„
T—
en tn
CM •-
en NO
ON ON
•h *
r^ r-
ON en
n
r-o
o o\
00^
* *
tn NO
ON CO
-d-tn
m tn
i- CM
CM m
i— ON
* .
ON 00
ON eo
•tf in
V
n
n
r-.
eo
CM
m
T—
r-
^
NO
•*
^
CM
en
m
CO
NO
r-
r-
-d-
.
i—
en
o
^>
CO
!*•
ON
m
in
„
T—
CM
CO
in
p-
ON
r-
v*'
en
.
CM
W
i-l
<
Z
o
E-*
Z
w
£>
•^
o
o
2
O
z
1
E-1
*-
,
CM
ON
ON
CM
in
i —
*
p<-
en
O
r-
CO
^~
CM
r_
en
m
CM
00
(K
NO
en
o
"
CM
o
CO
^
«
CM
CO
en
ON
00
^
m
en
o
•—
•*
vO
f**»
O
,
NO
NO
[^
ON
ON
„
<_
en
o
O
^.
f*^
O
f.
00
en
o
n
%
<;
Z
O
rH
H
Z
>
23
O
H
O
H
m
ON
o
o
„
CM O
O
en
_
O NO
00 0*
^ .
cn tri
«i
r-
CM
^
r-
,
00
CO
CM O
O
CM
4
CM CO
ON ON
VO
tn tn
*
NO
CM
"~
'-
00
**
CM
ON
«
CO O
o
„
^ In
NO ON
N
in m
*
in
CM
^
»—
m
^_
^
en
.
CO O
o
NO
en en
CJN ON
eo
— m
*
i—
CM
»—
ON
O
in
.j
m,
ON
CM
T—
n
CO
H
^E >^w
*C Vi
S — -
iJ 00
2 5
S ^
O rH
H w
>•! *V
|
|
*.
N»
r»
/si
-------
O>—Or-cM«-«eor-o
K m CM o i- m,. o ,—
ao co co ^ o
•CfvOCM -*ON
ro — ,-cn
a
o
1
r-. T—m r-o\ oo CM O r-. en «—ocooo
o en oo co O
Or-liH
_ o c
O 3 O
o
E_i PL.
OTH-*
HO
468
-------
z
JH
I
X
00
1-1
fe
§
M
H
469
-------
CM
0)
S
bO
470
-------
X
0)
H
fe eo
§
M
K
O
471
-------
i
X
0)
3
00
H
-fr
O
i-l
K
O
472
-------
H
2
H
m
i
X
60
•H
u u 1
C C W
flj OS CO
a u «
•H -H U U
M n C 5-
,0 * 0)
3 3 S 4J
_] -1 w M
M 4J 4) S
C C M
-------
-------
SECTION XI
NEW SOURCE PERFORMANCE STANDARDS
The basis for new source performance standards (NSPS) under
Section 306 of the Clean Water Act is the best available demon-
strated technology (BDT). New plants have the opportunity to
design the best and most efficient production processes and
wastewater treatment technologies. Therefore, BDT includes pro-
cess changes, in-plant controls (including elimination of waste-
water streams), operating procedure changes, and end-of-pipe
treatment technologies to reduce pollution to the maximum extent
possible. This section describes the control technology for
treatment of wastewater from new sources and presents mass dis-
charge limitations of regulated pollutants for NSPS, based on the
described control technology.
TECHNICAL APPROACH TO NSPS
All wastewater reduction and process changes applicable to a new
source have been considered previously for the BAT options.
These options are summarized below and presented in greater
detail in Section X (p. 451).
In summary form, the treatment technologies considered for new
copper forming facilities are:
Option 1 based on:
- Lime and settle (chemical precipitation of metals
followed by sedimentation), and where required,
- Hexavalent chromium reduction,
- Chemical emulsion breaking,
- Oil skimming, and
- Spray rinsing and recirculation of the rinse water for
pickled forged parts, and
- Recycle of hot rolling spent lubricant.
Option 2 based on:
Option 1, plus process wastewater flow reduction by the
following methods:
- Recycle of solution heat treatment contact cooling water,
475
-------
- Recycle of annealing contact cooling water, and
- Spray rinsing and recirculation of pickling rinsewater.
for all products.
Option 3 based on:
Option 2, plus polishing filtration (multimedia) at the end
of the Option 2 treatment train.
Option 4 based on:
Option 3, plus countercurrent cascade rinsing applied to the
pickling rinse stream for all products.
Option 5 based on:
Option 1, plus polishing filtration (multimedia) at the end
of the Option 1 treatment train.
NSPS OPTION SELECTION - 0*
EPA is establishing the best available demonstrated technology
for the copper forming category to be equ iva1ent to BAT—tech-
nology with the addition Of COUntercurrfnt casradg ringing fnr
picKllng rinsewater and the addition of filtffflUft" prior to di§r
jcharoe fnpi-ion A) The Agency recognizes that new sources have
the opportunity to implement more advanced levels of treatment
without incurring the costs of retrofit equipment, the costs of
partial or complete shutdown to install new equipment and the
costs to start up and stabilize the treatment system, as existing
systems would have to do.
Six copper forming plants use filtration technology as end-ofpipe
treatment prior to discharge or recycle of process water into the
plant. Four plants use countercurrent cascade rinsing on
pickling rinse lines. A technical description of these control
and treatment options is provided in Section VII. Countercurrent
cascade rinsing and filtration are appropriate technologies for
NSPS because they are demonstrated in this category and because
new plants have the opportunity to design and implement the most
efficient processes without retrofit costs and space availability
limitations. In addition, the Agency does not believe that
standards for new sources based on Option 4 will create a barrier
to entry.
476
-------
REGULATED POLLUTANT PARAMETERS
The Agency has no reason to believe that the pollutants that will
be found in significant quantities in wastewater from new sources
will be any different than those from existing sources. Conse-
quently, pollutants were selected for regulation in accordance
with the rationale of Section VI. These are the toxic metals
(chromium, copper, lead, nickel, and zinc), oil and grease, TSS,
and pH. Toxic organics are not regulated because they are effec-
tively controlled by the oil and grease limit. As discussed
under BAT, several toxic metals are not being specifically
regulated because they will be adequately controlled when the
regulated metals are treated to the levels achievable by the
model treatment technlogy. These metals include antimony,
arsenic, beryllium, cadmium, silver, and selenium.
DISCHARGE FLOWS
The discharge flows for NSPS are identical to those for BAT for
all waste streams except pickling rinse and pickling rinse for
forged parts. As was the case for BAT, the Agency reviewed the
water use and discharge practices of copper forming plants with
regard to each of the waste streams (Tables V-2 through V-13, pp.
90-105). EPA determined that additional flow reduction beyond
that developed for BAT was not demonstrated except for pickling
rinse water. As discussed in Section VII, countercurrent cascade
rinsing substantially improves the efficiencies of water use for
rinsing. For example, the use of a two-stage countercurrent
cascade rinse can reduce water usage to approximately one-tenth
of that needed for a single-stage rinse and achieve the same
level of product cleanliness (refer to example in Section VII,
p. 310). Similarly, a three-stage countercurrent cascade rinse
would reduce water usage to approximately one-thirtieth of the
original amount. Countercurrent cascade rinsing is practiced at
four copper forming plants.
The NSPS flow for pickling rinse water for other than forged
parts is based on the lowest production normalized flow observed
at a copper forming plant which uses countercurrent cascade
rinsing for pickling rinse. The NSPS regulatory flow is 585
1/kkg for pickling rinse.
The NSPS regulatory flow for pickling rinse for forged parts is
calculated by assuming that the turndown ratio from BAT pickling
rinse to NSPS pickling rinse will also be achieved for forged
parts. This turndown ratio is 2.22. Therefore, the NSPS regula-
tory flow for forged parts is 1760 1/kkg.
477
-------
COSTS AND ENVIRONMENTAL BENEFITS
The Agency developed a "normal" plant in order to estimate pollu-
tant removals and costs for new sources. The normal plant is a
theoretical plant which has each of the manufacturing operations
covered by the category and production that is the average level
of the dischargers in the category. Section VIII (p. 398) of
this document presents in detail the composition of the copper
forming normal plant. A new direct discharge normal plant having
the industry average annual production level would generate a raw
waste of 1,837 kg per year of toxic metal and organic pollutants.
The NSPS technology would reduce these pollutant levels to 75 kg
per year of these same toxic pollutants. The total capital
investment cost for a new normal plant to install NSPS technology
is estimated to be $1.23 million, compared with investment costs
of $1.18 million to install technology equivalent to BAT. Simi-
lar figures for total annual costs are $1.05 milion for NSPS and
$1.02 million for BAT. Therefore, new sources, regardless of
whether they result from major modifications of existing facili-
ties or are constructed as greenfield sites, will have costs
approximately equivalent to the costs existing sources without
treatment will incur in achieving BAT. The new source
performance standards will not pose a barrier to entry.
EFFLUENT STANDARDS
Table VII-20 (p. 336) presents the treatment effectiveness corre-
sponding to the NSPS treatment train for the pollutants selected.
Effluent concentrations (one day maximum and ten day average
values) are multiplied by the regulatory discharge flows summar-
ized in Table XI-1 to calculate the mass of pollutants allowed to
be discharged per mass of product. The results of these calcula-
tions are shown in Tables XI-2 through XI-18.
478
-------
Table XI-1
NEW SOURCE REGULATORY FLOWS FOR COPPER FORMING WASTE STREAMS
Waste Stream New Source Flow (1/kkg)
Hot Rolling Spent Lubricant 103
Cold Rolling Spent Lubricant 379
Drawing Spent Lubricant 85
Annealing Water 1,240
Annealing Oil 0
Solution Heat Treatment 646
Extrusion Press Heat Treatment 2
Pickling Fume Scrubber 626
Pickling Bath 11$
Alkaline Bath 46.7
Pickling Rinse (Forged Parts) 1,760 A
Pickling Rinse (All Other Parts) 585 A
Alkaline Rinse (Forged Parts) 12,642
Alkaline Rinse (All Other Parts) 4,214
Tumbling or Burnishing 583
Surface Coating 743
Miscellaneous Waste Streams 22.3
479
-------
Table XI-2
NSPS FOR HOT ROLLING SPENT LUBRICANT
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy hot rolled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy hot rolled
Chromium
0.038 0.015
Copper 0.131 0.062
Lead 0.010 0.0092
Nickel 0.056 0.038
Zinc 0.105 0.043
Oil and Grease 1-030 1.030
Tqs 1.545 1.236
PH C1) C1)
1Within the range of 7.5 to 10.0 at all times.
Table XI-3
NSPS FOR COLD ROLLING SPENT LUBRICANT
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy cold rolled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy cold rolled
Chromium 0.140 0.056
Copper 0.485 0.231
Lead 0.037 0.034
Nickel 0.208 0.140
Zinc 0.386 0.159
Oil and Grease 3.790
(5
1Within the range of 7.5 to 10.0 at all times.
480
-------
Table XI-4
NSPS FOR DRAWING SPENT LUBRICANT^
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy drawn
English Units - lb/1,000,000 off-lbs of copper or copper
alloy drawn
Chromium 0,031 0.012
Copper 0.108 0.051
Lead 0.0085 0.0076
Nickel 0.046 0.031
Zinc 0.086 0.035
Oil and Grease 0.85 0.85
TSS 1.275 1.020
pH (1) 0)
^Within the range of 7.5 to 10.0 at all times.
^Applicable only to drawers who treat and discharge spent
drawing lubricants.
Table XI-5
NSPS FOR SOLUTION HEAT TREATMENT
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy heat treated
English Units - lb/1,000,000 off-lbs of copper or copper
alloy heat treated
Chromium 0.239 0.096
Copper 0.826 0.394
Lead 0.064 0.058
Nickel 0.355 0.239
Zinc 0.658 0.271
Oil and Grease 6.460 6.460
TSS 9.690 7.752
pH (1) (1)
^Within the range of 7.5 to 10.0 at all times.
481
-------
Table XI-6
NSPS FOR EXTRUSION HEAT TREATMENT
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy heat treated on an extrusion press
English Units - lb/1,000,000 off-lbs of copper or copper
alloy heat treated on an extrusion press
Chromium
Copper
Lead
Nickel
Zinc
Oil and Grease
TSS
pH
0.00074
0*0020
0.00020
0.0010
0.0020
0.020
0.030
0.00030
0.0010
0.00018
0.00074
0.00084
0.020
0.024
1Within the range of 7.5 to 10.0 at all times.
Table XI-7
NSPS FOR ANNEALING WITH WATER
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy annealed
English Units - lb/1,000,000 off-lbs of copper or copper
alloy annealed
Chromium
Copper
Lead
Nickel
Zinc
Oil and Grease
TSS
pH
0.458
1.587
0.124
0.682
1.264
12.400
18.600
0
0
0
0
0
12
C1)
186
756
111
458
520
400
880
^Within the range of 7.5 to 10.0 at all times
482
-------
Table XI -8
NSPS FOR ANNEALING WITH OIL
Maximum
„ . .. ^ , „ For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy annealed
English Units - lb/1 ,000,000 off-lbs of copper or copper
alloy annealed
Chromium Q Q
Copper 0 0
Lead 00
Nickel 0 0
Zinc 00
Oil and Grease 0 0
TSS n 0
PH (T) (Y,
Within the range of 7.5 to 10.0 at all times.
Table XI-9
NSPS FOR ALKALINE CLEANING RINSE
Maximum
D „ _ „ .. For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy alkaline cleaned
English Units - lb/1 ,000, 000 off-lbs of copper or copper
alloy alkaline cleaned
Chromium 1 .559 0
Copper 5.393 2.570
Lead 0.421 0.379
*ickel 2.317 1.559
. „ 1.769
Oil and Grease 42.140 42.140
Tj?S 63.210 50.568
PH (1) 1
483
-------
Table XI-10
NSPS FOR ALKALINE CLEANING RINSE FOR FORGED PARTS
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
forged parts alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy forged parts alkaline cleaned
Chromium +, *n* -? -7-, -,
CooDer 16.181 7.711
Lead 1-264 1.137
Nickel 6.953 4.677
Zinc 12.894 5.309
Oil and Grease 126.420 126.420
TSS 189.630 151.704
pH C1) < >
1Within the range of 7.5 to 10.0 at all times.
Table XI-11
NSPS FOR ALKALINE CLEANING BATH
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy alkaline cleaned
Chromium 0.017 0.0070
Coooer 0-059 0.028
L°ad 0.0046 0.0042
Nickel 0-025 0.017
MlCRe 0.047 0.019
Oil and Grease 0.46 0.46
0.70 0.56
pH
Within the range of 7.5 to 10.0 at all times.
484
-------
Table XI-12
NSPS FOR PICKLING RINSE
Maximum
For Any
One
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled Hy
c£S™ °'216 0-087
Lead °'748 0-356
Nickel °-058 0-052
Zinc °-321 0-216
Oil and Grease °J*g 0.245
TSS ?'?^0 5.850
pH (f-775 j-020
1 Within the range of 7.5 to 10.0 at all times.
Table XI-13
NSPS FOR PICKLING RINSE FOR FORGED PARTS
Maximum
Pollutant or PoUntant Pron^ % *g ^^J*^
Metric Units - mg/off-kg of copper or copper alloy
T, T . , „ . forged parts pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy forged parts pickled
Chromium n */n . ~.
Copper ?•§*» 0-263
Lead 2.246 1.070
Nickel 0-J" 0.157
Zinc °'?65 0.649
Oil and Grease i}'™ 0-737
TSS ' •->-)U 17.550
pH 26.325 21.060
(1) (1)
1 Within the range of 7.5 to 10.0 at all times.
485
-------
Table XI-14
NSPS FOR PICKLING BATH
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day _ Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1 ,000,000 off-lbs of copper or copper
alloy pickled
Chromium 0.042 °-017
°-148 °*070
Lea 0.011 0.010
Nickel °-063 °'042
Zinc °-118 °-048
Oil and Grease -160 1-160
Within the range of 7.5 to 10.0 at all times.
Table XI-1 5
NSPS FOR PICKLING FUME SCRUBBER
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled
Nickel °-344 0.231
Zinc 0.638 0.262
Oil and Grease 6-260 6.260
TCO 9.390 7.512
J? ('> <*>
1Within the range of 7.5 to 10.0 at all times.
486
-------
Table XI-16
NSPS FOR TUMBLING OR BURNISHING
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
tumbled or burnished
English Units - lb/1,000,000 off-lbs of copper or copper
alloy tumbled or burnished
Chromium 0.215 0.087
Copper 0.746 0.355
Lead 0.058 0.052
Nickel 0.320 0.215
Zlnc 0,594 0.244
Oil and Grease 5.830 5.830
TSS 8.745 6.996
pH (1) (1)
1Within the range of 7.5 to 10,0 at all times.
Table XI-17
NSPS FOR SURFACE COATING
Maximum
_ ,. For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
surface coated
English Units - lb/1,000,000 off-lbs of copper or copper
alloy surface coated
Chromium 0.274 0.111
Copper 0.951 0.453
Lea<* 0.074 0.066
Nickel 0.408 0.274
$J?C j 0.757 0.312
Oil and Grease 7.430 7.430
TSS 11.145 8.916
PH (1) (1)
Within the range of 7.5 to 10.0 at all times.
487
-------
Table XI-18
NSPS FOR MISCELLANEOUS WASTE STREAMS
Maximum
For Any Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy formed
English Units - lb/1 ,000,000 off-lbs of copper or copper
alloy formed
Chromium 0.008 0.003
0.027 0.013
°-0021 °-0019
Nickel 0.011 0.008
Zinc 0.022 0
Oil and Grease 0.218 0.218
W 0) <1>
1 Within the range of 7.5 to 10.0 at all times.
488
-------
SECTION XII
PRETREATMENT STANDARDS
Section 307(b) of the Clean Water Act requires EPA to promulgate
pretreatment standards for existing sources (PSES), which must be
achieved within three years of promulgation. PSES are designed
to prevent the discharge of pollutants which pass through, inter-
fere with, or are otherwise incompatible with the operation of
publicly owned treatment works (POTW). The Clean Water Act
amendment of 1977 adds a new dimension by requiring pretreatment
for pollutants, such as heavy metals, that limit POTW sludge
management alternatives, including the beneficial use of sludges
on agricultural lands. The legislative history of the 1977 Act
indicates that pretreatment standards are to be technology based,
analogous to the best available technology for removal of toxic
pollutants.
Section 307(c) of the Act requires EPA to promulgate pretreatment
standards for new sources (PSNS) at the same time that it promul-
gates NSPS. New indirect discharge facilities, like new direct
discharge facilities, have the opportunity to incorporate the
best available demonstrated technologies, including process
changes, in-plant controls, and end-of-pipe treatment technol-
ogies, and to use plant site selection to ensure adequate treat-
ment system installation.
The General Pretreatment Regulations for Existing and New Sources
which serve as the framework for the final copper forming pre-
treatment standards are in 40 CFR Part 403, 46 FR 9404 (January
28, 1981). These regulations^describe the Agency's~6verall pol-
icy for establishing and enforcing pretreatment standards for new
and existing users of a POTW and delineate the responsibilities
and deadlines applicable to each part in this effort. In addi-
4ion' 40 ££B Part 403^ Section 403.5(b). outlines prohibited
qiscnarges which apply to all users of a POTW7" ~~
This section describes the treatment and control technology for
IggtCgafemejot of process wastewaters from existing sources and new
sources,and presents mass discharge limitations of regulated
pollutants for existing and new sources, based on the described
control technology.
DISCHARGE OF COPPER FORMING WASTEWATERS TO A POTW
There are approximately 45 plants in the copper forming category
which discharge to a POTW. The plants that may be affected by
pretreatment standards represent about 26 percent of all of the
copper forming plants.
>• c. // 7
489
-------
Pretreatment standards are established to ensure removal of pol-
lutants which interfere with, pass through, or are otherwise
incompatible with a POTW. A determination of which pollutants
may pass through or be incompatible with POTW operations, and
thus be subject to pretreatment standards, depends on the level
of treatment employed by the POTW. In general, more pollutants
will pass through or interfere with a POTW employing primary
treatment (usually physical separation by settling) than one
which has installed secondary treatment (settling plus biological
treatment).
Many of the pollutants contained in copper forming wastewater are
not biodegradable and are, therefore, ineffectively treated by
such systems. Furthermore, these wastes have been known to pass
through or interfere with the normal operations of these systems.
Problems associated with the discharge of pollutant parameters
identified in copper forming process wastewaters to POTW were
discussed in Section VI. The discussion covered pass-through,
interference and sludge use.
The Agency based the selection of pretreatment standards, for the
copper forming category on pass through of toxic pollutants at
POTW. For each toxic pollutant, the Agency compared the removal
rate achieved by the BAT model treatment system with the removal
rate at well operated POTW achieving secondary treatment. The
POTW removal rates were determined through a study conducted by
the Agency at over 40 POTW. (See Fate of Priority Pollutants in
Publicly Owned Treatment Works, EPA 440/1-82-303, September
1982.)
The average percentage of the toxic metals removed by a well-
operated POTW meeting secondary treatment requirements is about
50 percent (varying from 20 to 70 percent), whereas the percent-
age that can be removed by a copper forming direct discharger
applying the best available technology economically achievable is
more than 90 percent. Specific percent removals can be found in
Table XII-1. Accordingly, these pollutants pass through a POTW.
In addition to pass through of toxic metals, available informa-
tion shows that many of the toxic orqanics from copper forming
facilities also pass through a POT¥ZAspreviously mentioned,
toxic organics are not specifically regulated at BAT because, for
direct dischargers, the BPT oil and grease limit will adequately
control toxic organics. As demonstrated by the data presented in
Section VII, Table VII-10 (p. 326), and Table XII-1, direct
dischargers who comply with the BPT limitation for oil and grease
will remove a greater percentage of the toxic organics than a
well operated POTW achieving secondary treatment. POTW removal
of those toxic organic pollutants found in the sampled plants
averaged 62 percent; while the oil skimming component of the BPT
490
-------
technology basis achieves removals ranging from 85 to 97 percent.
Accordingly, EPA is promulgating a pretreatment standard for
toxic organics. The standard is referred to as total toxic
organ i cs (TTO) and def i ned as the sum of the masses or
concentrations of each of the 12 toxic organics listed in Table
XII-2 and found at concentrations above the quantification level
(0.01 mg/1).
Other toxic organics may be found at copper forming facilities.
Toxic organic compounds originate in lubricants and these com-
pounds can vary considerably depending on the formulation of the
lubricant. Many polyaromatic hydrocarbons and organic solvents
that perform the same function can be substituted for one
another. If substitution does occur, the Agency believes that
these other toxic organics are likely to be adequately controlled
by the PSES model technology. However, regulation of these other
toxic organics should be considered on a plant-by-plant basis by
the permitting authority.
The analysis of wastewaters for toxic organics is costly and
requires sophisticated equipment. Data indicate that the toxic
organics are in the oil and grease and by removing the oil and
grease, the toxic organics should also be removed. Therefore,
the Agency is promulgating an oil and grease standard as an
alternative to monitoring for TTO.
The pretreatment options selected provide for significantly more
removal of toxic pollutants than would occur if copper forming
wastewaters were discharged untreated to a POTW. Thus, pretreat-
ment standards will control the discharge of toxic pollutants to
POTW and prevent pass-through.
Mass-based limitations, which are the only method used for desig-
nating pretreatment standards, are set forth below. Regulation
on the basis of concentration only is not appropriate because it
does not ensure that plants will achieve pollutant reductions
consistent with plants implementing the flow reduction components
of the model treatment technology. Therefore, the Agency is not
promulgating alternative concentration-based pretreatment stan-
dards (40 CFR Part 403.6(c)).
TECHNICAL APPROACH TO PRETREATMENT
Under these standards, five levels of PSES and PSNS were evalu-
B«* for the Cate9°ry- Option 1 is BPT treatment. Option 2 is
BPT treatment plus flow reduction. Option 3 includes a filter in
addition to Option 2 treatment technology. Option 4 includes all
of the elements of Option 3 plus further reduction of the pick-
ling rinse flow through countercurrent cascade rinsing. Option 5
adds filtration as an end-of-pipe treatment process to Option 1.
491
-------
Each treatment technology option is based on central treatment of
all waste streams and results in the same concentrations of pol-
lutants in the effluent regardless of the number and combinations
of copper forming waste streams entering the treatment system.
Mass limitations derived from these options may vary between
plants because of the impact of different regulatory flows. The
derivation of these regulatory flows is discussed later in this
section.
In summary form, the treatment technologies considered for PSES
and PSNS for copper forming ares
Option 1 based on:
- Lime and settle (chemical precipitation of metals,
followed by sedimentation), and where required
- Chemical emulsion breaking,
- Oil skimming,
- Hexavalent chromium reduction,
- Spray rinsing and recirculation of the rinse water for
forged parts, and
- Recycle of hot rolling spent lubricant.
Option 1 is equivalent to the technologies on which BPT is based.
Option 2 based on:
Option 1, plus process wastewater flow reduction by the
following methods:
- Recycle of solution heat treatment contact cooling water,
- Recycle of annealing contact cooling water, and
- Spray rinsing and recirculation of pickling rinse water.
Option 3 based on:
Polishing filtration (multimedia) at the end of the Option 2
treatment train.
Option 4 based on:
Option 3, plus further reduction of the pickling
492
-------
rinse flow through the use of countercurrent cascade
rinsing.
Option 5 based on:
Option l, plus polishing filtration (multimedia) at the end
of the Option 1 treatment train.
PSES OPTION SELECTION 0*&^* £
is promulgating PSES based on the application of technology
Option 2, which is also the basis for BAT limitations",
,
consists of chemical precipitation and sedimentation, flow reduc-
tion, and preliminary treatment, where necessary, consisting of
chromium reduction, chemical emulsion breaking, and oil skimming.
Compliance with PSES based on this model treatment technology
will prevent pass through of toxic metals and organics.
In the proposed rule we stated that if BAT was promulgated with
filters then PSES would need to include filtration to prevent
pass through." Because this is not the case, PSES does not
include filtration. Option 4 was not chosen as the basis for
PSES for similar reasons.
Option 4 is based on the installation of countercurrent cascade
rinsing for rinse water associated with pickling. This technol-
ogy option was rejected for PSES because it was not chosen for
BAT, because it is only demonstrated at four copper forming
plants, and because most of the other existing plants lack
sufficient space to add the additional rinse tank and associated
piping required for countercurrent cascade rinsing.
Option 5 is based on filtration added to Option 1. Option 5 was
considered and ultimately rejected because as compared to Option
2 it provides only one-fourth as much pollutant removal at
approximately the same costs.
PSNS OPTION SELECTION
The technology basis for PSNS is npt^n 4J which is equivalent to
552* f 109y basis for N?PS' The A9ency has determined that
PSNS based on Option 4 is necessary to prevent pass through of
toxic metals and organics. In selecting the technology basis for
PSNS, the Agency compares the toxic pollutant removal achieved by
a well-operated POTW to that achieved by a direct discharger
meeting NSPS. New indirect dischargers, like new direct dis-
chargers, have the opportunity to design and implement the most
efficient processes without retrofit costs and space availability
limitations. J
493
-------
COSTS AND ENVIRONMENTAL BENEFITS OF PSES AND PSNS
The application of PSES will remove 18,700 kilograms per year of
toxic pollutants (metals and organics) beyond current discharge
levels. EPA estimates that the capital investment costs of com-
plying with PSES is $9.2 million with a total annual cost of $7.7
million (1982 dollars).
The Agency developed a normal plant to estimate costs and pollu-
tant removals for new sources (PSNS). The copper forming normal
plant is described in detail in Section VIII of this document. A
new indirect discharge normal plant having the industry average
annual production level would generate a raw waste of 1,837 kg of
toxic metal and organic pollutants. The PSNS technology would
reduce these pollutant levels to 75 kg toxic pollutants. The
total capital investment cost for a new normal plant to install
PSNS technology is estimated to be $1.23 million, compared with
investment costs of $1.18 million to install technology equiva-
lent to PSES. Similar figures for total annual costs are $1.05
million for NSPS and $1.02 million for BAT. Therefore, new
sources, regardless of whether they result from major modifica-
tions of existing facilities or are constructed as greenfield
sites, will have costs approximately equivalent to the costs
existing sources without treatment will incur in achieving PSES.
The new source performance pretreatment standards will not pose a
barrier to entry.
REGULATED POLLUTANT PARAMETERS
Twelve toxic organics have been selected since they may pass
through a POTW as discussed above. They are listed in Table XII-
2. As discussed above, oil and grease is being promulgated as an
alternate monitoring parameter for both PSES and PSNS, since
removal of oil and grease through the application of oil skimming
effectively removes these 12 toxic organics. The toxic metals
selected are chromium (total), copper, lead, nickel, and zinc.
TSS is not regulated since it is adequately handled by a POTW and
will not interfere with its operation.
EFFLUENT STANDARDS
Table VI1-20 (p. 336) presents the treatment effectiveness corre-
sponding to the BAT treatment train for the pollutants selected,
which is equivalent to the PSES and PSNS treatment train. Efflu-
ent concentrations (one day maximum and ten day average values)
are multiplied by the regulatory discharge flows summarized in
Table X-l (p. 457) for PSES and Table XI-1 (p. 477) for PSNS to
calculate the mass of pollutants allowed to be discharged per
mass of product. The results of these calculations for PSES are
494
-------
shown in Tables XII-3 through XII-19, and for PSNS are shown in
Tables XII-20 through XII-36.
495
-------
Table XII-1
PERCENT REMOVAL BY A POTW OF POLLUTANTS REGULATED AT PSES
Chromium (total)
Copper
Lead
Nickel
Zinc
Benzene
1 ,1,1-Trichloroethane
Chloroform
2,6-Dinitrotoluene
Ethylbenzene
Methylene Chloride
Naphthalene
N-nitrosodiphenylamine
Anthracene
Phenanthrene
Toluene
Trichloroethylene
65
58
48
19
65
66
80
11
No data available
86
3
85
No data available
70
73
70
72
496
-------
Table XI1-2
TOXIC ORGANICS THAT COMPRISE TTO
1 . Benzene (4)*
2. 1,1,1-Trichloroethane (11)
3. Chloroform (23)
4. 2,6-Dinitrotoluene (36)
5. Ethylbenzene (38)
6. Methylene chloride (44)
7. Napthalene (55)
8. N-nitrosodiphenylaraine (62)
9. Anthracene (78)
10. Phenanthrene (81)
11. Toluene (86)
12. Trichloroethylene (87)
*The number in parentheses refers to the number of this organic
on the list of 129 toxic pollutants (see Table V-1).
497
-------
Table XII-3
PSES FOR HOT ROLLING SPENT LUBRICANT
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy hot rolled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy hot rolled
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
045
195
015
197
150
066
2.060
018
103
013
130
062
035
236
Table XII-4
PSES FOR COLD ROLLING SPENT LUBRICANT
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy cold rolled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy cold rolled
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.166
0.720
0.056
0.727
0.553
0.246
7.580
0.068
0.379
0.049
0.481
0.231
0.128
4.548
498
-------
Table XII-5
PSES FOR DRAWING SPENT LUBRICANT1
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy drawn
English Units - lb/1,000,000 off-lbs of copper or copper
alloy drawn
Chromium 0.037
Copper 0.161
Lead 0.012
Nickel 0.163
Zinc 0.124
TTO 0.055
Oil and Grease (for alternate 1.700
monitoring)
^Applicable only to drawers who treat and discharge spent
drawing lubricants.
0.015
0.085
0.011
0.107
0.051
0.028
1.020
Table XII-6
PSES FOR SOLUTION HEAT TREATMENT
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy heat treated
English Units - lb/1,000,000 off-lbs of copper or copper
alloy heat treated
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.284
1.227
0.096
1.240
0.943
0.419
12.920
0.116
0.646
0.083
0.820
0.394
0.219
7.752
499
-------
Table XII-7
PSES FOR EXTRUSION HEAT TREATMENT
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy heat treated on an extrusion press
English Units - lb/1,000,000 off-lbs of copper or copper
alloy heat treated on an extrusion press
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.00088
0.0030
0.00030
0.0030
0.0020
0.0010
0.040
0.00036
0.0020
0.00026
0.0020
0.0010
0.00068
0.024
Table XII-8
PSES FOR ANNEALING WITH WATER
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
annealed with water
English Units - lb/1,000,000 off-lbs of copper or copper
alloy annealed with water
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.545
2.356
0.186
2.380
1.810
0.806
24.800
0.223
1.240
0.161
1.574
0.756
0.421
14.880
500
-------
Table XII-9
PSES FOR ANNEALING WITH OIL
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
annealed with oil
English Units - lb/1,000,000 off-lbs of copper or copper
alloy annealed with oil
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table XII-10
PSES FOR ALKALINE CLEANING RINSE
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy alkaline cleaned
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
1.854
8.006
0.632
8.090
6.152
2.739
84.280
0.758
4.214
0.547
5.351
2.570
1.432
50.568
501
-------
Table XII-11
PSES FOR ALKALINE CLEANING RINSE FOR FORGED PARTS
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
forged parts alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy forged parts alkaline cleaned
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
5.562
24.019
1.896
24.272
18.457
8.217
252.840
2,
12,
1,
16,
7.
4
151,
275
642
643
055
711
298
704
Table XII-12
PSES FOR ALKALINE CLEANING BATH
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy alkaline cleaned
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.020
0.088
0.0070
0.089
0.068
0.030
0.93
0.0084
0.046
0.0060
0.059
0.028
0.015
0.56
502
-------
Table XII-13
PSES FOR PICKLING RINSE
Pollutant or Pollutant Property
Maximum
For Any
One Pay
Maximum for
Monthly Average
Metric Units - rag /off -kg of copper or copper alloy pickled
English Units - lb/1 , 000,000 off-lbs of copper or copper
alloy pickled
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0. 574
2.481
0.195
2.507
1.906
0.848
26.120
0. 235
1.306
0.169
1.658
0.796
0.444
15.672
Table XII-14
PSES FOR PICKLING RINSE FOR FORGED PARTS
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
forged parts pickled
English Units - lb/1 ,000, 000 off-lbs of copper or copper
alloy forged parts pickled
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
1 . 723
7.444
0.587
7
5
522
720
2.546
78.360
0. 705
3.918
0.509
4.975
2.389
1.332
47.016
503
-------
Table XII-15
PSES FOR PICKLING BATH
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.051
0.220
0.017
0.222
0.169
0.075
2.320
0.020
0.116
0.015
0.147
0.070
0.039
1.392
Table XII-16
PSES FOR PICKLING FUME SCRUBBER
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
275
189
093
201
913
406
12.520
112
626
081
795
381
212
7.512
504
-------
Table XII-17
PSES FOR TUMBLING OR BURNISHING
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
tumbled or burnished
English Units - lb/1,000,000 off-lbs of copper or copper
alloy tumbled or burnished
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0,
1,
0,
t,
0,
0,
256
107
087
119
851
378
11.660
0.104
0.583
0.075
0.740
0.355
0.198
6.996
Table XII-18
PSES FOR SURFACE COATING
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
surface coated
English Units - lb/1,000,000 off-lbs of copper or copper
alloy surface coated
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0,
1,
0,
1,
1,
0,
326
411
111
426
084
482
14.860
0.133
0.743
0.096
0.943
0.453
0.252
8.916
505
-------
Table XII-19
PSES FOR MISCELLANEOUS WASTE STREAMS
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy formed
English Units - lb/1,000,000 off-lbs of copper or copper
alloy formed
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.009
0.041
0.003
0.041
0.031
0.014
0.436
0.003
0.021
0.002
0.027
0.013
0.007
0.261
Table XII-20
PSNS FOR HOT ROLLING SPENT LUBRICANT
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy hot rolled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy hot rolled
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.038
0.131
0.010
0.056
0.105
0.035
1.030
0.015
0.062
0.0092
0.038
0.043
0.035
1.030
506
-------
Table XII-21
PSNS FOR COLD ROLLING SPENT LUBRICANT
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy cold rolled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy cold rolled
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.140
0.485
0.037
0.208
0.386
0.128
3.790
0.056
0.231
0.034
0.140
0.159
0.128
3.790
Table XII-22
PSNS FOR DRAWING SPENT LUBRICANT1
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy drawn
English Units - Ib/T,000,000 off-lbs of copper or copper
alloy drawn
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.031
0.108
0.0085
0.046
0.086
0.028
0.850
0.012
0.051
0.0076
0.031
0.035
0.028
0.850
^Applicable only to drawers who treat and discharge spent
drawing lubricants.
507
-------
Table XII-23
PSNS FOR SOLUTION HEAT TREATMENT
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy heat treated
English Units - lb/1,000,000 off-lbs of copper or copper
alloy heat treated
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.239
0.826
0.064
0.355
0.658
0.219
6.460
0.096
0.394
0.058
0.239
0.271
0.219
6.460
Table XII-24
PSNS FOR EXTRUSION HEAT TREATMENT
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy heat treated on an extrusion press
English Units - lb/1,000,000 off-lbs of copper or copper
alloy heat treated on an extrusion press
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.00074
0.0020
0.00020
0.0010
0.0020
0.00068
0.020
0.00030
0.0010
0.00018
0.00074
0.0084
0.00068
0.020
508
-------
Table XII-25
PSNS FOR ANNEALING WITH WATER
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
annealed with water
English Units - lb/1,000,000 off-lbs of copper or copper
alloy annealed with water
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
458
587
124
682
264
421
12.400
0,
0,
0,
0.
0,
0.
186
756
111
458
520
421
12.400
Table XII-26
PSNS FOR ANNEALING WITH OIL
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
annealed with oil
English Units - lb/1,000,000 off-lbs of copper or copper
alloy annealed with oil
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
509
-------
Table XII-27
PSNS FOR ALKALINE CLEANING RINSE
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy alkaline cleaned
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
1.559
5.393
0.421
2.317
4.298
1.432
42.140
0.632
2.570
0.379
1.559
1.769
1.432
42.140
Table XII-28
PSNS FOR ALKALINE CLEANING RINSE FOR FORGED PARTS
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
forged parts alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy forged parts alkaline cleaned
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
4,
16,
1.
6,
12,
4,
677
181
264
953
894
298
126.420
896
711
137
677
309
298
126.420
510
-------
Table XII-29
PSNS FOR ALKALINE CLEANING BATH
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper
alloy alkaline cleaned
English Units - lb/1,000,000 off-lbs of copper or copper
alloy alkaline cleaned
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.017
0.059
0.0046
0.025
0.047
0.015
0.46
0.0070
0.028
0.0042
0.017
0.019
0.015
0.46
Table XII-30
PSNS FOR PICKLING RINSE
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.216
0.748
0.058
0.321
0.596
0.198
5.850
0.087
0.356
0.052
0.216
0.245
0.198
5.850
511
-------
Table XII-31
PSNS FOR PICKLING RINSE FOR FORGED PARTS
Po1lutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - rag/off-kg of copper or copper alloy
forged parts pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy forged parts pickled
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.649
2.246
0.175
0.965
1.790
0.596
17.550
0.263
1.070
0.157
0.649
0.737
0.596
17.550
Table XII-32
PSNS FOR PICKLING BATH
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0,
0,
0,
0,
0,
0
1
042
148
011
063
118
039
160
0.017
0.070
0.010
0.042
0.048
0.039
1.160
512
-------
Table XII-33
PSNS FOR PICKLING FUME SCRUBBER
Maximum
» 11 fc „ « ,, For ^y Maximum for
Pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy pickled
English Units - lb/1,000,000 off-lbs of copper or copper
alloy pickled
Chromium 0.231 0.093
0.801 0.381
0.062 0.056
0.344 0.231
0.638 0<262
A jo ,* °'212 0-212
Oil and Grease (for alternate 6,260 6 260
monitoring)
Table XII-34
PSNS FOR TUMBLING OR BURNISHING
Maximum
- .... „ ,, For Any Maximum for
pollutant or Pollutant Property One Day Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
tumbled or burnished
English Units - lb/1,000,000 off-lbs of copper or copper
alloy tumbled or burnished
Chromium 0.215 0,087
Copper 0,746 0-355
0.058 0.052
0,320 0.215
0-594 0.244
A ,< ,* °'198 °'198
and Grease (for alternate 5.830 5.830
monitoring)
513
-------
Table XII-35
PSNS FOR SURFACE COATING
Pollutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy
surface coated
English Units - lb/1,000,000 off-lbs of copper or copper
alloy surface coated
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.274
0.951
0.074
0.408
0.757
0.252
7.430
0.111
0.453
0.066
0.274
0.312
0.252
7.430
Table XII-36
PSNS FOR MISCELLANEOUS WASTE STREAMS
Po1lutant or Pollutant Property
Maximum
For Any
One Day
Maximum for
Monthly Average
Metric Units - mg/off-kg of copper or copper alloy formed
English Units - lb/1,000,000 off-lbs of copper or copper
alloy formed
Chromium
Copper
Lead
Nickel
Zinc
TTO
Oil and Grease (for alternate
monitoring)
0.008
0.027
0.0021
0.011
0.022
0.007
0.218
0,
0,
0,
0,
0
0
003
0013
0019
008
,009
007
0.218
514
-------
SECTION XIII
BEST CONVENTIONAL POLLUTANT CONTROL TECHNOLOGY
}*7l.^?n*mente**te* Section 301<2) biological oxygen demanding ^ollStanS
HS^lJ^ft1 sVspen?f3 solids (TSS>< f«cal coliform, and pH, and
v2^™ft"i?n^ PS"«tant8 defined by the Administrator as "con-
ventional [oil and grease, 44 FR 44501, July 30, 1979].
?SLiS*n0t an ?dditjonal limitation but replaces BAT for the con-
trol of conventional pollutants. In addition to the other fac-
tors specified in Section 304
-------
-------
SECTION XIV
ACKNOWLEDGEMENTS
-. -drfft of tne Proposed document was prepared by
Standard, a division of the United Technologies Corpora-
"" ^ntract No. 68-01-4408. The proposed document was
•_*».«*- ** revised, and the final document prepared at the
Contract No!e68-0?-l529PA perSOnnel ^ Radian Corporation under
S*iirfl5irt HaT?Iin? Proframs w?re conducted under the leadership
of Mr. Mark Hellstein of Hamilton Standard. Preparation and
°K thu ini£iaJ drafts of the Proposed document was accom-
bX uMr' Daniel Lizdis, Mr. Robert Blazer, Mr. Edward
Mr',Mark Hellstein. Mr. James Sherman, Program Man-
»nu , , -
Mr J0hnr^h»n HHereth'.P^j!C^ Director, Mr. John Vidumsky and
r 0n»n .
nr;^n a" ave contributed in specific assignments in the
preparation of the proposed document.
Mr. Mark Hereth, Project Director, Ms. Heidi R. Welner Task
Leader and Ms. Karen L. Christensen' have contributed to the
nn
Ma?«°J!CVa^-COnducied b^ the Environmental Protection Agency,
Metals & Machinery Branch, Mr. Ernst P. Hall, Chief! The
P°ffr is M -
tchnica nr * '- e Prevo
technical project officers were Mr. Dave Pepson and Mr. John
Williams, who was assisted by Mr. Robert McCann. The project's
P
h JiU W€ller' who contributed to this
The economic project officer is Ms. Ann Watkins
'
The cooperation of the Copper and Brass Fabricators Council
f«™T£! ' t^leir technical committee and the individual copper
detailed fSEUi?? ^°Se PlantS W6re Sampled and who submitted
r requests
Acknowledgement and appreciation is also given to the secretarial
S Lnhn. Phdtf" Corporation (Ms. Nancy Reid, Ms. Sandra Moore,
™;«,?ap. ,.P«lllpS ??d Ms- Pamela A"«shey) and to the word pro-
2?fi 9McSta" ,°! the E«lue"t Guidelines Division (Ms. plarl
Smith, Ms. Carol Swann, and Ms. Glenda Nesby) for their efforts
r
517
-------
-------
SECTION XV
GLOSSARY
This section is an alphabetical listing of technical terms,
abbreviations, and acronyms used in this document which mav not
be familiar to the reader. y t
4-AAP Colorimetric Method
for total phenols and total phenolic com-
-M~4-4~- --*-1- the color developing agent 4-
Acid Dip
h purpose of craning any material. Two
methods of acid cleaning are pickling and oxidizing.
Acidity
h!)L~qUan*UatiVS caPacity °f aqueous solutions to react with
hydroxyl ions. Measured by titration with a standard solution of
Derate? 2/?^ied e"2 P°int' Usually exP^^d as milligrams
per liter of calcium carbonate.
The Act
The Federal Water Pollution Control Act Amendments of 1972 (33
(PL 95-217) Seq')' as amended by the Clean Water Act of 1977
Agency
The United States Environmental Protection Agency.
Aging
orrnrn th£ .Pr°Pertief °* certain metals and alloys that
worklna or ^n+ °%mod?^tely elevated temperatures after hot
natural nr «^ - treatment quench aging in ferrous alloys,
£?££ I „%* artl^cial a^xn9 in ^rrous and nonferrous alloys) or
after a cold working operation (strain aging).
Alkaline Cleaning
A process where dirt, mineral and animal fats, and oils are
removed from the metal surface by exposure to solutions at hfgh
519
-------
temperatures containing alkaline compounds, such as caustic soda,
soda ash, alkaline silicates, and alkaline phosphates.
Alkaline Cleaning Bath
A bath consisting of an alkaline cleaning solution through which
a workpiece is processed.
Alkaline Cleaning Rinse
A rinse following an alkaline cleaning bath through which a work-
piece is processed. A rinse consisting of a series of rinse
tanks is considered as a single rinse.
Alkalinity
The capacity of water to neutralize acids, a property imparted by
the water's content of carbonates, bicarbonates, hydroxides, and
occasionally borates, silicates, and phosphates. It is measured
by titration with a standardized acid to a specified end point,
and is usually reported in milligrams per liter of calcium
carbonate.
Amortization
The allocation of a cost or account according to a specified
schedule, based on the principal, interest and period of cost
allocation.
Analytical Quantification Level
The minimum concentration at which quantification of a specified
pollutant can be reliably measured.
Ancillary Operation
Any operation associated with a primary forming operation. These
ancillary operations include surface and heat treatment, hydro-
testing, sawing, and surface coating.
Anneal ing
A generic term describing a metals treatment process that is used
primarily to soften metallic materials, but also to simultane-
ously produce desired changes in other properties or in micro-
structure. The purpose of such changes may be, but is not
confined to, improvement of machinability, facilitation of cold
work, improvement of mechanical or electrical properties, and/or
increase in stability of dimensions. Annealing consists of heat-
520
-------
ing and cooling the metal at varying rates to achieve the desired
properties.
Annealing with Oil
The use of oil to quench a workpiece as it passes from an
annealing furnace.
Annealing with Water
The use of a water spray or bath, of which water is the major
constituent, to quench a workpiece as it passes from an annealing
furnace. y
Backwashino
The operation of cleaning a filter or column by reversing the
flow of liquid through it and washing out matter previously
trapped. *
Batch Treatment
A waste treatment method where wastewater is collected over a
period of time and then treated prior to discharge. Treatment is
not continuous, but collection may be continuous.
Bench Scale Pilot Studies
Experiments providing data concerning the treatability of a
wastewater stream or the efficiency of a treatment process con-
ducted using laboratory-size equipment.
Best Available Demonstrated Technology (BDT)
Treatment technology upon which new source performance standards
are based, as defined by Section 306 of the Act.
Best Available Technology Economically Achievable (BAT)
Level of technology applicable to toxic and nonconventional pol-
lutants on which effluent limitations are established. These
limitations are to be achieved by July 1, 1984 by industrial dis-
charges to surface waters as defined by Section 301(b)(2)(C) of
the Act.
Best Conventional Pollutant Control Technology (BCT)
Level of technology applicable to conventional pollutant effluent
limitations to be achieved by July 1, 1984 for industrial dis-
521
-------
charges to surface waters as defined in Section 301(b)(2)(E) of
the act.
Best Management Practices (BMP)
Regulations intended to control the release of toxic and hazard-
ous pollutants from plant runoff, spillage, leaks, solid waste
disposal, and drainage from raw material storage. These regu-
lations are defined in Section 304{e) of the Act.
Best Practicable Control Technology Currently Available (BPT)
Level of technology applicable to effluent limitations to have
been achieved by July 1, 1977 (originally) for industrial dis-
charges to surface waters as defined by Section 301(b)O)(A) of
the Act.
Billet
A long slender cast product used as raw material in subsequent
forming operations.
Biochemical Oxygen Demand (BOD)
The quantity of oxygen used in the biochemical oxidation of
organic matter under specified conditions for a specified time.
Slowdown
The minimum discharge of circulating water for the purpose of
discharging dissolved solids or other contaminants contained in
the water, the further buildup of which would cause concentration
in amounts exceeding limits established by best engineering
practice.
Catalyst
An agent that (1) reduces the energy required for activating a
chemical reaction and (2) is not consumed by that reaction.
Chelation
The formation of coordinate covalent bonds between a central
metal ion and a liquid that contains two or more sites for com-
bination with the metal ion.
Chemical Finishing
Producing a desired finish on the surface of a metallic product
by immersing the workpiece in a chemical bath.
522
-------
Chemical Oxygen Demand (COD)
A measure of the oxygen-consuming capacity of the organic and
inorganic matter present in the water or wastewater.
Clean Water Act (see the Act)
Cold Rolling
The process of rolling a workpiece below the recrystallization
temperature of the copper or copper alloy.
Colloid
Suspended solids whose diameter may vary between less than one
micron and fifteen microns.
Composite Samples
A series of samples collected over a period of time but combined
into a single sample for analysis. The individual samples can be
taken after a specified amount of time has passed (time compo-
sited), or after a specified volume of water has passed the sam-
pling point (flow composited). The sample can be automatically
collected and composited by a sampler or can be manually
collected and combined.
Consent Decree (Settlement Agreement)
Agreement between EPA and various environmental groups, as insti-
tuted by the United States District Court for the District of
Columbia, directing EPA to study and promulgate regulations for
the toxic pollutants (NRDC, Inc. v. Train, 8 ERC 2120 (D.D.C.
1976); modified 12 ERC 1833, D.D.C. 1979); modified by order
dated October 26, 1982.
Contact Water
Any water or oil that comes into direct contact with the copper,
whether it is raw material, intermediate product, waste product,
or finished product.
Continuous Casting
A casting process that produces sheet, rod, or other long shapes
by solidifying the metal while it is being poured through an
open-ended mold using little or no contact cooling water. Thus,
no restrictions are placed on the length of the product and it is
not necessary to stop the process to remove the cast product.
523
-------
Continuous Treatment
Treatment of waste streams operating without interruption as
opposed to batch treatment. Sometimes referred to as flowthrough
treatment.
Contractor Removal (Contract Hauling)
Disposal of oils, spent solutions, or sludge by a commercial
firm.
Conventional Pollutants
Constitutents of wastewater as determined by Section 304(a)(4) of
the Act, including but not limited to pollutants classified as
biological-oxygen-demanding, oil and grease, suspended solids,
fecal coliform, and pH.
Cooling Tower
A hollow, vertical structure with internal baffles designed to
break up falling water so that it is cooled by upward-flowing air
and the evaporation of water.
Countercurrent Cascade Rinsing
A staged process that employs recycled, often untreated water as
a rinsing medium to clean metal products. Water flow is opposite
to product flow so that the most contaminated water encounters
the incoming product first.
Data Collection Portfolio (dcp)
The questionnaire used in the survey of the copper forming
industry.
Desmutting
A process that removes a residual silt (smut) by immersing the
product in an acid solution, usually nitric acid.
Direct Discharger
Any point source that discharges or may discharge pollutants to a
surface water.
524
-------
Draqout
The solution that adheres to the objects removed from a bath or
rinse, more precisely defined as that solution which is carried
past the edge of the tank.
Drawing
Pulling the workpiece through a die or succession of dies to
reduce the diameter or alter the shape.
Drying Beds
Areas for dewatering of sludge by evaporation and seepage.
Effluent
Wastewater discharge from a point source.
Effluent Limitation
Any standard (including schedules of compliance) established by a
state or EPA on quantities, rates, and concentrations of chemi-
cal, physical, biological, and other constituents that are dis-
charged from point sources into navigable waters, the waters of
the contiguous zone, or the ocean.
Electrostatic Precipitator (ESP)
A gas cleaning device that induces an electrical charge on a
solid particle which is then attracted to an oppositely charged
collector plate. The collector plates are intermittently
vibrated to discharge the collected dust to a hopper.
Emulsifying Aaent
A material that increases the stability of a dispersion of one
liquid in another.
Emulsions
Stable dispersions of two immiscible liquids.
End-of-Pipe Treatment
The reduction of pollutants by wastewater treatment just prior to
discharge or reuse, after all product contact is finished.
Extrusion
The application of pressure to a copper workpiece, forcing the
copper to flow through a die orifice.
525
-------
Extrusion Heat Treatment
The spray application of water to a workpiece immediately
following extrusion for the purpose of heat treatment.
Finishing
The coating or polishing of a metal surface.
Forging
A process that exerts pressure on die or rolls surrounding heated
copper stock forcing the stock to take the shape of the dies.
Gas Chromatographv/Mass Spectroscopv (GC/MS)
Chemical analytical instrumentation used for quantitative organic
analysis.
Grab Sample
A single sample of wastewater taken without regard to time or
flow.
Heat Treatment
The application or removal of heat to a workpiece to change the
physical properties of the metal.
Indirect Discharger
Any point source that discharges or may discharge pollutants to a
publicly owned treatment works.
Inductively-Coupled Argon Plasma Spectroohotometer (ICAP)
A laboratory device used for the analysis of metals.
Ingot
A large, block-shaped casting produced by various methods.
Ingots are intermediate products from which other products are
made.
In-Process Control Technology
Any procedure or equipment used to conserve chemicals and water
throughout the production operations, resulting in a reduction of
the wastewater volume.
526
-------
New Source Performance Standards (NSPS)
Effluent limitations for new industrial point sources as defined
by Section 306 of the Act.
Nonconventlonal Pollutant
Parameters selected for use in performance standards that have
not been previously designated as either conventional or toxic
pollutants.
Non-Water Quality Environmental Impact
The ecological impact as a result of solid, air, or thermal pol-
lution due to the application of various wastewater technologies
to achieve the effluent guidelines limitations. Also associated
with the non-water quality aspect is the energy impact of waste-
water treatment.
NPDES Permits
Permits issued by EPA or an approved state program under the
National Pollution Discharge Elimination System, Section 402 of
the Act.
Off-Gases
Gases, vapors, and fumes produced as a result of a copper forming
operation.
Off-Kilogram (Off-Pound)
The mass of copper or copper alloy removed from a forming or
ancillary operation at the end of a process cycle for transfer to
a different machine or process.
Oil and Grease (O&G)
Any material that is extracted by freon from an acidified sample
and that is not volatilized during the analysis/ such as hydro-
carbons, fatty acids, soaps, fats, waxes, and oils.
2H
The pH is the negative logarithm of the hydrogen ion activity of
a solution.
527
-------
Pickling
The process of removing scale, oxide, or foreign matter from the
surface of metal by immersing it in a bath containing a suitable
chemical reagent, often sulfuric acid that will attack the oxide
or scale, but will not act appreciably upon the metal during the
period of pickling. Frequently it is necessary to immerse the
metal in a detergent solution or to degrease it before pickling.
Pickling Bath
Any chemical bath (other than alkaline cleaning) through which a
workpiece is processed.
Pickling Fume Scrubber
The process of using an air pollution control device to remove
particulates and fumes from air above a pickling bath by
entraining the pollutants in water.
Pickling Rinse
A rinse, other than an alkaline cleaning rinse, through which a
workpiece is processed. A rinse consisting of a series of rinse
tanks is considered as a single rinse.
Plate
A flat, extended, rigid body of copper having a thickness greater
than or equal to 6.3 mm (0.25 inches).
Pollutant Parameters
Those constituents of wastewater determined to be detrimental
and, therefore, requiring control.
Priority Pollutants
The 129 specific pollutants established by the EPA from the 65
pollutants and classes of pollutants as outlined in the consent
decree of June 8, 1976.
Process Water
Water used in a production process that contacts the product, raw
materials, or reagents.
528
-------
Production Normalizing Parameter (PNP)
The unit of production specified in the regulations used to
determine the mass of pollution a production facility may
discharge.
Pretreatment Standards for Existing Sources (PSES)
Pretreatment standards (effluent regulations) for existing
sources of indirect discharges under Section 307(b) of the Act.
Pretreatment Standards for New Sources (PSNS)
Pretreatment standards (effluent regulations) for new sources of
indirect discharges under Section (b) and (c) of the Act.
Publicly Owned Treatment Works (POTW)
A waste treatment facility that is owned by a state or
municipality.
Quantification Level (see Analytical Quantification Level).
Recycle
Returning treated or untreated wastewater to the production pro-
cess from which it originated for use as process water.
Reduction
A reaction in which there is a decrease in valence resulting from
a gain in electrons.
Resource Conservation and Recovery Act (RCRA)
The Resource Conservation and Recovery Act (Pub. L. 94-580) of
1976, Amendments to the Solid Waste Disposal Act.
Reuse
The use of treated or untreated process wastewater in a different
production process.
Rinsing
A process in which water is used to wash cleaning chemicals from
the surface of metal.
529
-------
Rolling
A reduction in the thickness or diameter of a workpiece by
passing it between rollers.
Scrubber Liquor
The untreated wastewater stream produced by wet scrubbers clean-
ing gases produced by aluminum forming operations.
Seal Water
A water curtain used as a barrier between the annealing furnance
atmosphere and the outside atmosphere.
Semi-Continuous Casting (see Direct Chill Casting)
Semi-Fabricated Products
Intermediate products that are the final product of one process
and the raw material for a second process.
Settlement Agreement (see Consent Decree)
Solution Heat Treatment
The process of introducing a workpiece into a quench bath for the
purpose of heat treatment following rolling, drawing, or
extrusion.
Spent Lubricant
Water or an oil-water mixture which is used in forming operations
to reduce friction, heat and wear and ultimately discharged.
Stationary Casting
A process in which the molten copper is poured into molds and
allowed to air-cool. It is often used to recycle in-house scrap.
Strain-Hardening (see work-hardening)
Subcategorization
The process of segmentation of an industry into groups of plants
for which uniform effluent limitations can be established.
530
-------
Surface Water
Any visible stream or body of water, natural or man-made. This
does not include bodies of water whose sole purpose is wastewater
retention or the removal of pollutants, such as holding ponds or
lagoons. * *
Surfactants
Surface active chemicals that tend to lower the surface tension
between liquids.
Swaging
A process in which a solid point is formed at the end of a tube,
rod, or bar by the repeated blows of one or more pairs of oppos-
ing dies. It is often the initial step in the drawing process.
Total Dissolved Solids (TDS)
Organic and inorganic molecules and ions that are in true solu-
tion in the water or wastewater.
Total Organic Carbon (TOO
A measure of the organic contaminants in a wastewater. The TOC
analysis does not measure as much of the organics as the COD or
BOD tests,*but is much quicker than these tests.
Total Recycle
The complete reuse of a stream, with makeup water added for
evaporative losses. There is no blowdown stream from a totally
recycled flow and the process water is not periodically or con-
tinuously discharged.
Total Suspended Solids (TSS)
Solids in suspension in water, wastewater, or treated effluent.
Also known as suspended solids.
Total Toxic Organics (TTO)
The sum of the masses or concentrations of each of the following
toxic organic compounds which is found at a concentration greater
than 0.010 mg/1: benzene, 1,1,1-trichloroethane, chloroform,
2,6-dinitrotoluene, ethylbenzene, methylene chloride, naphtha-
lene, N-nitrosodiphenylamine, anthracene, phenanthrene, toluene,
trichloroethylene.
531
-------
Tubing Blank
A sample taken by passing one gallon of distilled water through a
composite sampling device before initiation of actual wastewater
sampling.
Volatile Substances
Materials that readily vaporize at relatively low temperatures.
Wet Scrubbers
Air pollution control devices used for removing pollutants from a
gas as it passes through a liquid spray.
Wire
A slender strand of copper with a diameter of less than 9.5 mm
(3/8 inches).
Work-Harden i nq
An increase in hardness and strength and a loss of ductility that
occurs in the workpiece as a result of passing through cold form-
ing or cold working operations. (Also known as strain-hardening).
Zero Discharger
Any industrial or municipal facility that does not discharge
wastewater.
532
-------
SECTION XVI
REFERENCES
Adin, A., Baumann, E. R., Cleasby, J. L., 1979, "The Application
of Filtration Theory to Pilot-Plant Design,M Journal of the
American Water Works Association. January.
Alloid Colloids, Inc. brochure.
American Society for Metals, 1964, Heat Treating. Cleaning, and
Finishing. Metals Handbook, 8th ed., Vol. 2, OH.
American Society for Metals, 1970, Forging and Casting, Metals
Handbook, 8th ed., Vol. 5, OH.
Amstead, B. H., Ostwald, P. F., Begeman, M. L., 1977,
Manufacturing Processes. 7th ed., John Wiley & Sons, NY.
"Antimony" Final Water Quality Criteria, PB117319, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
API, 1969, Manual on Disposal of. Refinery Wastes; Volume on
Liquid Wastes, 1st ed., American Petroleum Institute, Washington,
Argo and Wesner, 1976, "AWT Energy Needs a Prime Concern," Water
and Wastes Engineering, 13:5:24.
"Arsenic" Final Water Quality Criteria, PB117327, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
Banerji and O'Conner, 1977, "Designing More Energy Efficient
Wastewater Treatment Plants," Civil Engineering ASCE. 47:7:76.
Bansal, I. K., 1977, "Reverse Osmosis and Oltrafiltration of Oily
and Pulping Effluents," Industrial Wastes. May/June.
Barnard, J. L., Eckenfelder, W. W. Jr., 1971, Treatment Cost
Relationships for Industrial Waste Treatment, Technical Report
#23, Vanderbilt University.
Bauer, D., 1976, "Treatment of Oily Wastes—Oil Recovery Pro-
grams," Presented at 31st Annual Purdue Industrial Waste Confer-
ence.
533
-------
Basselievre, E. B., Schwartz, M., 1976, The Treatment of Indus-
trial Wastes, McGraw-Hill Book Co., New York, NY.
"Benzene" Final Water Quality Criteria, PB117293, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
"Beryllium" Final Water Quality Criteria, FB117350, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
Brody, M. A., Lumpkins, R. J., 1977, "Performance of Dual Media
Filters," Chemical Engineering Progress, April.
Burns and Roe, 1979, Draft Technical Report for the Paint Indus-
try.
"Cadmium" Final Water Quality Criteria, FBI 17368, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980.
"Carbon Tetrachloride" Final Water Quality Criteria, PB117376,
Criteria and Standards Division, Office of Water Regulations and
Standards (45 FR 79318-79379, November 28, 1980).
Carborundum, 1977, "Dissolved Air Flotation Systems," December.
Catalytic, Inc., 1979, Treatment Catalogue for the Catalytic
Computer Model.
Chemical Marketing Reporter, March 17, 1978.
Cheremisinoff, P. N., Ellerbusch, F., 1978, Carbon Adsorption
Handbook, Ann Arbor Science, Ann Arbor, MI.
Chieu, J. H., Gloyna, E. F., Schechter, R. S., 1975, "Coalescence
of Emulsified Oily Wastewater by Fibrous Beds," Presented at the
30th Annual Purdue Industrial Waste Conference.
"Chlorobenzene" Final Water Quality Criteria, PB117392, Criteria
and and Standards Division, Office of Water Regulations and
Standards (45 FR 79318-79379, November 28, 1980).
"Chloroform" Final Water Quality Criteria,-PB117442, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
534
-------
"Chromium" Final Water Quality Criteria, FBI 17467, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318- 79379, November 28, 1980).
Clark, J. W., Viessman, W., Hammer, M. S., 1977, Water Supply and
Pollution Control. IEP-A Dun-Donnelley Publisher, New Yorx, NY*
"Copper" Final Water Quality Criteria, FBI 17475, Criteria and
Standards Division Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
Gulp and Gulp, 1974, New Concepts in Water Purification, Van
Nostrand Reinhold, New York, NY.
Gulp, R. L., Wesner, G. M., Gulp, G. L., 1978, Handbook of
Advanced Wastewater Treatment. Van Nostrand Reinhold Company, New
York, NY.
Davies, B. T., Vose, R. W., 1977, "Custom Designs Cut Effluent
Treatment Costs, Case Histories at Chevron, U.S.A., Inc.," Purdue
Industrial Waste Conference, p. 1035.
Denyo, D. J., ed., 1978, Unit Operations for Treatment of
Hazardous Wastes. ~
Dickey, 1970, "Managing Waste Heat with the Water Cooling Tower,"
Marley Co.
Dugas, R. S., Reed, P. £., 1977, "Successful Pretreatment and
Deep Well Injection of Chemical Plant Wastewater," Presented at
32nd Annual Purdue Industrial Waste Conference.
Dynatech RID Company, 1969, A Survey of Alternate Methods for
Cooling Condenser Discharge Water. Large-ScaleHeat Rejection
Equipment. EPA Project No. 16130DH3.
Eckenfelder, W. W. Jr., O'Connor, D. J., 1961, Biological Waste
Treatment. Pergamon Press, NY.
Envirodyne, "Dissolved Air Flotation & Solids Settling - Model
Jupitor - 7,000."
Environmental Quality Systems, Inc., 1973, Technical and Economic
Review of. Advanced Waste Treatment Processes.
"Ethylbenzene" Final Water Quality Criteria, PB117590, Criteria
and Standards Division, Office of Water Regulations and Standards
(45 FR 79318-79379, November 28, 1980).
Federal Register, 43 FR 2150.
535
-------
Federal Register, 44 FR 15926.
Federal Register, 44 FR 28716.
Federal Register, 44 FR 43660.
Federal Register, 44 FR 56628.
Ford, D. L., Elton, R. L., 1977, "Removal of Oil and Grease from
Industrial Wastewaters," Chemical Engineering, October 17, p.
49.
Gloyna, E. F., Ford, D. L., 1974, Cited by Osamor, F. A., Ahlert,
R. C., 1978, in Oil Water Separation; State-of-the-Art, U.S.
Environmental Protection Agency, Cincinnati, OH, PB-280 755.
Gross, A. C., 1979, "The Market for Water Management Chemicals,"
Environmental Science £ Technology, 13:9:1050.
Guthrie, K. M., 1969, "Capital Cost Estimating," Chemical Engi-
neering, March 24.
Hagan and Roberts, 1976, "Energy Requirements for Wastewater
Treatment Plants, Part 2," Water and Sewage Works, 124:12:52.
Hager, D. G., 1974, "Industrial Wastewater Treatment by GAC,"
Industrial Water Engineering, 11:1:18.
Hammer, M. J-, 1975, Water and Wastewater Technology, John Wiley
& Sons, Inc., New York, NY.
Hawley, Gessner G., rev.. The Condensed Chemical Dictionary, 9th
ed.
Hockenbury, M. R., Loven, A. W., 1977, "Treating Metal Forging
and Processing Wastewater," Industrial Wastes, 23:3:45.
Howes, Robert and Kent, Robert, 1970, Hazardous Chemicals
Handling and Disposal, Noyes Data Corp., Park Ridge, NJ.
Hsiung, K. Y-, Mueller, H. M., Conley, W. R., 1974, "Physical-
Chemical Treatment for Oily Waste," Presented at WWEMA Industrial
Water Pollution Conference and Exposition, Detroit, MI, Cited by
Osamor, F. A., Ahlert, R. C., 1978, Oil/Water Separation; State-
of -the-Art, U.S. Environmental Protection Agency, Cincinnati, OH,
PB-280 755.
Hutchins, R. A., 1975, "Thermal Regeneration Costs," Chemical
Engineering Prog., 71:5:80.
536
-------
Industrial Water Engineering. 1970, "Cooling Towers - Special
Report," May.
Infilco Degremont, Inc., 1974, "Sediflotor Clarifier," Company
Brochure DB830, September.
Jones, H. R., 1971, Environmental Control in the Organic and
Petrochemical Industries, Noyes Data Corp., Park Ridge, NJ.
Journal of Metal Finishing; "Guidelines for Wastewater
Treatment, September and October, 1977.
Katnick, K. E., Pavilcius, A. M., 1978, "A Novel Chemical
Approach for the Treatment of Oily Wastewaters," Presented at
33rd Annual Purdue Industrial Waste Conference.
Kirk-Othmer, Encyclopedia of Chemical Technology, 2nd ed., 1963,
Interscience Publishers, New York, NY.
Koon, J, H., Adams, C. E. Jr., Eckenfelder, W. W., 1973,
"Analysis of National Industrial Water Pollution Control Costs,"
Associated Water and Air Resources Engineers, Inc.
Krockta, H., Lucas, R. L., 1972, "Information Required for the
Selection and Performance Evaluation of Wet Scrubbers," Journal
2i the Air Pollution Control Association. June.
Kumar, J. I., Clesceri, N. L., 1973, "Phosphorus Removal from
Wastewaters: A Cost Analysis," Water & Sewage Works, 120:3:82.
Lacey, R. E., 1972, "Membrane Separation Processes," Chemical
Engineering. Sept. 4.
Lange, Norbert, Adolph, 1973, Handbook of Chemistry, McGraw-Hill,
New York, NY.
"Lead" Final Water Quality Criteria, PB117681, Criteria and
Standards Division, Qffice of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
Lee, E. L., Schwab, R. E., 1978, "Treatment of Oily Machinery
Waste," Presented at 33rd Annual Purdue Industrial Waste Con-
ference.
"Lime for Water and Wastewater Treatment: Engineering Data,"
BIF, Providence, Ref. No. 1.21-24.
Lin, Y. G., Lawson, J. R., 1973, "Treatment of Oily and Metal
Containing Wastewater," Pollution Engineering, November.
537
-------
Lopez, C. X., Johnston, R., 1977, "Industrial Wastewater Recy-
cling with Ultrafiltration and Reverse Osmosis," Presented at the
32nd Annual Purdue Industrial Waste Conference.
Lund, H. F., ed., 1971, Industrial Pollution Control Handbook,
McGraw-Hill Book Co., New York, NY.
Luthy, R. G., Selleck, R. E., Galloway, 1978, "Removal of Emulsi-
fied Oil with Organic Coagulants and Dissolved Air Flotation,"
Journal Water Pollution Control Federation, 50:2:331.
Maeder, E. G., 1975, "The D&I Can: How & Why it Does More with
Less Metal," Modern Metals, August, pp. 55-62.
McKee, J. E. and Wolf, H. W., ed., 1963, Water Quality Criteria.
2nd ed.. The Resources Agency of California, State Water Quality
Control Board, Publication No. 3-A.
McKinney, R. E., 1962, Microbiology for Sanitary Engineers,
McGraw-Hill Book Co., Inc., NY.
"Mercury" Final Water Quality Criteria, PB117699, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
Myansnikov, I. N-, Butseva, L. N-, Gandurina, L. B., 1979, "The
Effectiveness of Flotation Treatments with Flocculants Applied to
Oil Wastewaters," Presented at USEPA Treatment of Oil Containing
Wastewaters, April 18 to 19, 1979, Cincinnati, OH.
National Commission on Water Quality, 1976, Water Pollution
Abatement Technology; Capabilities and Cost, PB-250 690-03.
"Naphthalene" Final Water Quality Criteria, PB117707, Criteria
and Standards Division, Office of Water Regulations and Standards
(45 FR 79318-79379, November 28, 1980).
Nebolsine, R., 1970, "New Methods for Treatment of Wastewater
Streams," Presented at 25th Annual Purdue Industrial Waste Con-
ference.
"Nickel" Final Water Quality Criteria, PB117715, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
NTIS, 1974, Cost o£ Dissolved Air Flotation Thickening of Waste
Activated Sludge at Municipal Sewage Treatment Plants, PB-226-
582.
538
-------
Osamor, F. A., Ahlert, R. C., 1978, Oily Water Separation;
State-of-the-Art, U.S. Environmental Protection Agency,
Cincinnati, OH, EPA-600/2-78-069,
Patterson, James W., Wastewater Treatment Technology.
Patterson, J. W., 1976, "Technology and Economics of Industrial
Pollution Abatement," Illinois Institute for Environmental Qual-
ity, Document No. 76/22.
Peoples, R. F., Krishnan, P., Simonsen, R. N., 1972, "Nonbiologi-
cal Treatment of Refinery Wastewater,H Journal Water Pollution
Control Federation, November.
Personal communication with Dave Baldwin of Tenco Hydro, Inc.
Personal communication with Jeff Busse of Envirex.
Personal communication with Envirodyne sales representative.
Personal communication with Goad, Larry and Company.
Personal communication with Kerry Kovacs of Komiine-Sanderson.
Personal communication with Don Montroy of the Brenco Corporation
representing AFL Industries.
Personal communication with Jack Walters of Infilco-Degremont,
Inc.
Personal communication with Leon Zeigler of Air-o-Flow.
"Phenol" Final Water Quality Criteria, PB117772, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
"Phthalate Ester" Final Water Quality Criteria, PB117780,
Criteria and Standards Division, Office of Water Regulations and
Standards (45 FR 79318-79379, November 28, 1980).
Pielkenroad Separator Company brochure.
Quinn, R., Hendershaw, W. K., 1976, MA Comparison of Current
Membrane Systems Used in Ultrafiltration and Reverse Osmosis,"
Industrial Water Engineering.
"Polynuclear Aromatic Hydrocarbons" Final Water Quality Criteria,
PB117806, Criteria and Standards Division, Office of Water
Regulations and Standards (45 FR 79318-79379, November 28, 1980).
539
-------
Richardson Engineering Services, Inc., 1980, General Construction
Estimating Standards, Solana Beach, CA.
Rizzo, J. L., Shephard, A. R., 1977a, "Treating Industrial Waste-
water with Activated Carbon," Chemical Engineering, January 3, p.
95.
Rizzo, J. L., Shephard, A. R., 1977b, "Treating Industrial Waste-
water with Activated Carbon," Chemical Engineering, September 3.
Roberts, K. L., Weeter, D. W., Ball, R. 0., 1978, "Dissolved Air
Flotation Performance," 33rd Annual Purdue Industrial Waste Con-
ference, p. 194.
Sabadell, J. E., ed., 1973, Traces of Heavy Metals in Water
Removal Processes and Monitoring, USEPA, 902/9-74-001.
Sawyer, C. N., McCarty, P. L., 1967, Chemistry for Sanitary
Engineering, McGraw-Hill Book Co., NY.
Sax, N. Irving, , Dangerous Properties of Industrial
Materials, Van Nostrand Reinhold Co., New York, NY.
Sax, N. Irving, 1974, Industrial Pollution, Van Nostrand Reinhold
Co., New York, NY.
Sebastian, F. P., Lachtman, D. W., Kominek, E., Lash, L., 1979,
"Treatment of Oil Wastes Through Chemical, Mechanical, and Ther-
mal Methods," Symposium; Treatment of. Oil-Containing Wastewater,
April 18-19, Cincinnati, OH.
Seiden and Patel, Mathematical Model of Tertiary Treatment by.
Lime Addition, TWRC-14.
Smith, J. E., 1977, "Inventory of Energy Use in Wastewater Sludge
Treatment and Disposal," Industrial Water Engineering, 14:4:20.
"Selenium" Final Water Quality Criteria, PB117814, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
"Silver" Final Water Quality Criteria, PB117822, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
Smith, R., 1968, "Cost of Conventional and Advanced Treatment of
Wastewater," Journal Water Pollution Control Federation,
40:9:1546.
540
-------
Sonksen, M. K., Sittig,fM. F., Maziarz, E F., 1978, "Treatment of
Oily Wastes by Ultrafiltration/Reverse Osmosis - A Case History,"
Presented at 33rd Annual Purdue Industrial Waste Conference.
Spatz, D. D., 1974, "Methods of Water Purification," Presented to
the American Association of Nephrology Nurses and Technicians of
the NSAIO-AANNT Joint Conference, Seattle, Washington, April
1972, Revised July 1974.
Steel, E. W., 1960, Water Supply and Sewerage, McGraw-Hill Book
Company, Inc., New York, NY.
Strier, M. P., 1978, "Treatability of Organic Priority Pollutants
- Part C - Their Estimated {30-Day Average) Treated Effluent Con-
centration - A Molecular Engineering Approach," Report to Robert
B. Schaffer, Director, EPA Effluent Guidelines Division, July 11-
and "Treatability of Organic Priority Pollutants - Part D - The
Pesticides - Their Estimated (30-Day Average) Treated Effluent
Concentration," December 26.
Symons, J. M., 1978, Interim Treatment Guide for Controlling
Organic Contaminants in Drinking Water Using Granular Activated
Carbon, Water Supply Research Division, Municipal Environmental
Research Laboratory, Office of Research and Development,
Cincinnati, OH.
Tabakin, R. B., Trattner, R., Cheremisinoff, P. N., 1978a,
Oil/Water Separation Technology: The Options Available - Part
I/" Water and Sewage Works, Vol. 125, No. 8, August.
Tabakin, R. B., Trattner, R., Cheremisinoff, P. N., 1978b,
Oil/Water Separation Technology: The Options Available - Part
2/" Water and Sewage Works, Vol. 125, No. 8, August.
"Tetrachloroethylene" Final Water Quality Criteria, PB117830,
Criteria and Standards Division, Office of Water Regulations and
Standards (45 FR 79318-79379, November 28, 1980).
Thompson, C. S., 1972, "Cost and Operating Factors for Treatment
of Oily Waste Water," Oil and Gas Journal, 70:47:53.
Throup, W. M., 1976, "Why Industrial Wastewater Pretreatment?"
Industrial Wastes, July/August, p. 32.
"Toluene" Final Water Quality Criteria, PB117855, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
U.S. Department of Interior, FWPCA, 1967, Industrial Waste
Profile No. 5. Petroleum Refining, Vol. III.
541
-------
U.S. Department of Interior, 1968a, Cost of Wastewater Treatment
Processes, TWRC-6.
U.S. Department of Interior, 1968b, Preliminary Design and
Simulation of Conventional Wastewater Renovation Systems Using
the Digital Computer, USDI-WP-20-9.
U.S. Department of Interior, 1969, Appraisal of Granular Carbon
Contacting, Report No. TWRC-12.
U.S. Environmental Protection Agency, 1971a, Estimating Costs and
Manpower Requirements for Conventional Wastewater Treatment
Facilities, Water Pollution Control Research Series, 17090 DAN.
U.S. Environmental Protection Agency, 1971b, Experimental
Evaluation of Fibrous Bed Coalescers for Separating Oil-Water
Emulsions, 12050 DRC, November.
U.S. Environmental Protection Agency, 1973a, Capital and
Operating Costs of Pollution Control Equipment Module - Vol. II,
EPA-R5-73-023b.
U.S. Environmental Protection Agency, 1973b, Electrical Power
Consumption for Municipal Wastewater Treatment, EPA-R2-73-281.
U.S. Environmental Protection Agency, 1973c, Estimating Staffing
for Municipal Wastewater Treatment Facilities, EPA-68-01-0328.
U.S. Environmental Protection Agency, 1973d, Process Design
Manual for Carbon Adsorption, EPA-625/l-71-002a.
U.S. Environmental Protection Agency, 1974c, Flow Equalization,
EPA-625/4-74-006.
U.S. Environmental Protection Agency, 1974d, Policy Statement on
Acceptable Methods of Utilization or Disposal or Sludges,
Washington, D.C..
U.S. Environmental Protection Agency, 1974g, "Wastewater
Filtration-Design Considerations," EPA Technology Transfer
Seminar Publication, July.
U.S. Environmental Protection Agency, 1975a, A Guide to the
Selection of Cost-Effective Wastewater Treatment System, EPA-
430/9-75-002.
U.S. Environmental Protection Agency, 1975b, Costs of Wastewater
Treatment by Land Application, EPA-430/9-75-003, June.
542
-------
2me!?tal Protection Agency, 1975c, Evaluation of Land
Systems, EPA-430/9-75-001 , March. -- ^^
2«; Environmental Protection Agency, 1 975d, Lime Use in
Wastewater Treatment Design and Cost Data, EPA-60072^75-0387 ~~
*r?t!ction Agency, 1975e, Process Design
Solids Removal . EPA-625/l-75-003a~; — -
c Pro£ect*°n Agency, 1976a, Cost Estimating
Sewer Overflow Storage and Treatm^nT. EPA-600/2-
/O— "
£°n?ent?1 «2£ectlon AgencV' 1976b, Land Treatment of
Wastewater Effluents. Design Factors rT, EPA TecK^
nology Transfer Seminar Publicatiolu -- "
U.S. Environmental Protection Agency, 1976c, Land Treatment of
Municipal Wastewater Effluents. Design Factors ^TT, EPA TecF
nology Transfer Seminar Publicatioru -- —
U.S. Environmental Protection Agency 1976d, Land Treatment of
%!££!^3g?!^% Case Historiei, ~EPA Technologf
iransrer Seminar Publication.
U.S. Environmental Protection Agency, 1977b, Controlling
Pollution from the Manufacturing and Coating of Metal — Products-
Wa|er Pollution Control, Technology Transfer~May7"EPA-625/3-77-
2lir0n5ent?1 pfotection Agency, 1977d, State-of-the-Art of
Water Treatment Systems, Office of WateFTu^pT^. -- ~
prmn Pr^tection Agency, 1977e, Supplement for
gretreatment to the Development Document for The Petroleum
Re£in*"q industry Existing. PoinTSource Catigor^" March.
U.S. Environmental Protection Agency, 1978a, Analysis of
^^i
— 77— 0 1 4 .
pfotection Agency, 1978b, Construction Costs
Wastewater Conveyance System; 1973-1977? ~
" •'
!rotection Agency, 1978c, Construction Costs
Wastewater Treatment Plants; T973-1977, EPA-43075^
77—013. "'" ""' ' ™
543
-------
U.S. Environmental Protection Agency, 1978e, Estimating Costs for
Water Treatment as a Function of Size and Treatment Plant
Efficiency, EPA-600/2-78/182.
U.S. Environmental Protection Agency, 1978f, Innovative and
Alternative Technology Assessment Manual, EPA-430/9-78-009.
U.S. Environmental Protection Agency, 1978g, Process Design
Manual for Municipal Sludge Landfills, USEPA Technology Transfer,
EPA-625/1-78-010, SW-705, October.
U.S. Environmental Protection Agency, 1978h, Revised Economic
Impact Analysis of Proposed Regulations on Organic Contamination
Drinking Water, Office of Drinking Water.
U.S. Environmental Protection Agency, 1979a, Dissolved Air_
Flotation of. Gulf Shrimp Cannery Wastewater, EPA-600/2-79-061.
U.S. Environmental Protection Agency, 1979d, Process Design
Manual for Sludge Treatment and Disposal, EPA-625/1-79-011,
September.
U.S. Environmental Protection Agency, U.S. Army Corps of
Engineers, U.S. Department of Agriculture, 1977, Process Design
Manual for Land Treatment of Municipal Wastewater, EPA-625/1-77-
008, October.
Verschueren and Karel, 1972, Handbook of Environmental Data on
Organic Chemicals, Van Nostrand Reinhold Co., New York, NY.
Wahl, J. R., Hayes, T. C., Kleper, M. H., Pinto, S. D., 1979,
"Ultrafiltration for Today's Oily Wastewaters: A Survey of
Current Ultrafiltration Systems," Presented at 34th Annual Purdue
Industrial Waste Conference.
Water Pollution Control Federation, 1977, MOP/8: Wastewater
Treatment Plant Design, WPCF, Washington, D.C.
Wyatt, M. J., White, P. E. Jr., 1975, Sludge Processing,
Transportation, and Disposal/Resource Recovery; A Planning
Perspective, Report No. EPA-WA-75-R024, December.
Zievers, J. F., Grain, R. A., Barclay, F. G., 1968, "Waste
Treatment in Metal Finishing: U.S. and European Practices,"
C i ted by Technology and Economics of Industrial Pollution
Abatement, Illinois Institute for Environmental Quality, Document
No. 76/22. as well as other pollutants including halogenated
organics.
544
-------
"Zinc" Final Water Quality Criteria, PB117897, Criteria and
Standards Division, Office of Water Regulations and Standards (45
FR 79318-79379, November 28, 1980).
GOVERNMENT PRINTING OFFICE; 198«* 421 5*5 118;Ct
545
-------
-------
-------
-------
-------
-------
-------
-------