United States
Environmental Protection
Agency
Water Engineering
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/S2-88/032 July 1988
&EPA Project Summary
Evaluation of Biological
Treatment of Pharmaceutical
Wastewater with PAC Addition
David A. Gardner and Richard A. Osantowski
A lacK of information on applicable
removal technologies for total
chemical oxygen demand (TCOD)
prevented promulgation of best
available technology economically
achievable (BAT) limitations and new
source performance standards
(NSPS) for TCOO for pharmaceutical
manufacturing plants in 1983
(EPA/440/1-83/084). Therefore, in
1984 U.S. EPA conducted a pilot plant
study of activated carbon treatment
technologies utilizing pharmaceutical
wastewaters from a manufacturing
plant that produces fermentation
products (Subcategory A) and
chemical synthesis products
(Subcategory C). One technology
that was evaluated was powdered
activated carbon (PAC) addition to an
activated sludge system (PACT). A
viscous floating mass of mixed liquor
solids (VFMLS) developed in the
PACT units and resulted in
premature termination of the study.
Therefore, in 1987 an additional pilot
study was performed at the site of
the 1984 study. The purposes of this
study were to: 1) attempt to find the
cause of the formation of the VFMLS,
2) generate additional research data
for TCOD removal from phar-
maceutical wastewater using the
PACT process, 3) evaluate the
efficiency of PACT in removing
specific organics, 4) evaluate the
"Registered Patent Process. Mention of trade
names or commercial products does not
constitute endorsement or recommendation for
use.
effectiveness of PACT in reducing
efflu-ent aquatic toxicity, and 5)
evaluate the use of a selector to
improve the settling characteristics
of the mixed liquor. One control unit,
two PACT units, and a unit equipped
with a series of selector basins were
operated.
This Project Summary was
developed by EPA's Water Engineering
Research Laboratory, Cincinnati, OH,
to announce key findings of the
research project that is fully
documented in a separate report of
the same title (see Project Report
ordering information at back).
Introduction
In November 1982. the EPA proposed
effluent limitations and standards for the
pharmaceutical manufacturing point
source category. The proposed BAT and
NSPS limited the discharge of the
nonconventional pollutant, TCOD, from
existing and new sources. However, due
to a lack of information on applicable
TCOD removal technologies for
subcategories A (fermentation products)
and C (chemical synthesis products),
limitations and standards for TCOD were
not promulgated along with other
regulations on October 27, 1983.
By way of responding to these
additional information needs, from
September to December 1984, EPA
conducted biological and physical-
chemical pilot plant evaluations of
activated carbon treatment technologies
utilizing actual pharmaceutical
wastewaters. The biological treatment
systems consisted of three activated
sludge units operated in parallel. PAC
-------
was added to two of the units in selected
dosages. The third unit was used as a
control. The PAC enhanced biological
treatment systems operated during the
1984 test period reduced influent TCOD
concentration to levels below those
required by the 1976 best practicable
control technology currently available
(BPT) regulation. This regulation required
an average 74% reduction from raw
waste levels. PAC also improved the
settling rate of the mixed liquor
suspended solids (MLSS) when
compared to the control unit. A VFMLS
developed in the PACT units near the
end of the acclimation period for the
second set of PAC dosages and resulted
in premature termination of the study.
The VFMLS did not appear in the control.
Due to the formation of the VFMLS, it
was decided that additional information
was required before a PACT system
could be considered as a viable
treatment process for subcategories A
and C pharmaceutical wastewaters.
Therefore, from March to July 1987
additional biological pilot plant studies
were performed at the site of the original
1984 pilot tests. Four biological pilot
units were used in the 1987 study. One
unit was operated as a control, two units
were operated with PAC addition to the
aeration basins, and one unit was
operated with a series of selector basins
ahead of the aeration basin.
The purposes of this study were to: 1)
follow up on the previous work and
attempt to find the cause of the formation
of the VFMLS, 2) generate additional
research data for TCOD removal from
pharmaceutical wastewater using the
PACT process, 3) evaluate the efficiency
of PACT in removing specific organics,
4) evaluate the effectiveness of PACT in
reducing effluent aquatic toxicity as
measured by bioassay tests, and 5)
evaluate the use of a selector to improve
the settling characteristics of the mixed
liquor.
Quality Assurance/Quality
Control Methods
Sample analyses were conducted
on-site in a field laboratory and in a
base laboratory in another state. All
samples were collected by the pilot plant
operators using prelabeled containers.
Analyses for pH, TCOD, soluble
chemical oxygen demand (SCOD),
nitrogen inhibited biochemical oxygen
demand (NIBOD), nitrogen inhibited
soluble biochemical oxygen demand
(NISBOD), chloride, total suspended
solids (TSS), and volatile suspended
solids (VSS) were performed at the on-
site laboratory. All other analyses were
performed at the base laboratory. A
portable computer was also located in
the laboratory trailer during the study to
perform engineering and analytical
calculations and to store and transmit
data between the field site and home
office.
All samples were iced during
collection, refrigerated after collection,
and iced during shipment to the base
laboratory (samples that were analyzed
on-site were usually analyzed the same
day they were collected but were
preserved for reanalysis if necessary).
Samples that were sent to the base
laboratory for soluble phosphate (SP),
nitrate + nitrite (N03 + N02), and
ammonia (NHs) analysis and samples
analyzed on-site for TCOD and SCOD
were preserved with sulfuric acid addition
to pH 2. All samples for soluble
parameters were filtered through 0.45 pm
filter paper prior to preservation. Samples
for chloride analysis were shipped to the
home laboratory unpreserved.
TCOD and SCOD analyses were
performed by the Hach colorimetric
method (Hach Water Analysis Handbook,
No. 11-01-84-SED, Hach Chemical
Company, Loveland, Colorado, 1984). All
other analyses for the conventional
parameters were performed according to
the procedures described in Methods for
Chemical Analysis of Water and Wastes
(EPA/600/4-79-020, U.S. Environ-
mental Protection Agency, Cincinnati,
Ohio, 1979) or Standard Methods for the
Examination of Water and Wastewater,
15th Ed. (1980). At least 20% of all
samples were analyzed in replicate for all
conventional parameters except NIBOD
and NISBOD. One sample each of
NIBOD and NISBOD was duplicated
each day that analyses were performed.
At least 10% of all samples were spiked
with appropriate reagents for analysis of
all conventional parameters except TSS,
VSS, NIBOD, and NISBOD. Blanks
and/or standards were analyzed with
each analytical run or sample lot as
appropriate for the analysis.
QA/QC objectives for precision were
to have a maximum of 20% difference
between replicates for NIBOD, NISBOD,
and VSS. A maximum of 15% difference
between replicates was sought for all
other conventional parameters. Accuracy
objectives were ± 20% spiked sample
recovery for NIBOD and NISBOD, and a
± 15% spiked sample recovery for other
parameters.
Of 2,131 replicate samples, 2,093
(98.2%) were within the precision
percent difference criteria. Of 190 spiked
samples, 186 (97.9%) were within the
percent recovery objectives. In all, 3,300
analyses were performed, with 3.6% of
the analytical results deleted for QA/QC
reasons. The project had a 95.8%
completion rate for planned analyses.
During the two intensive test periods,
samples were analyzed for specific
organic compounds, for aquatic toxicity,
and by the toxicity characteristic leaching
procedure (TCLP) at various contract
laboratories. EPA approved methods
were used for all analyses.
Pilot Study Procedures
This study consisted of three separate
parts: 1) the PACT study to evaluate the
PACT process, 2) the selector study to
evaluate the use of selector technology
for improved mixed liquor settling, and 3)
bench tests to try and reproduce the
VFMLS.
PACT Study
From March to June 1987, a 101-day
study was conducted using one
biological pilot plant as the control and
two biological pilot plants as the
experimental (PACT) systems. The three
activated sludge units were operated ir
parallel.
System Operation-
Raw pharmaceutical wastewater was
collected just before it entered the full
scale aeration basins and was used a.'
the feed to the pilot units. This flov
consisted of equalized pharmaceutica
wastewater with a nominal amount (abou
2%) of macerated, chlorinated sanitar
waste.
The three activated sludge units wen
identified as Unit 1 (control), Unit .'
(PACT unit), and Unit 3 (PACT unit;
Each system consisted of a rectangula
aeration tank (189 L) and a conice
clarifier (47.3 L). Each aeration tank wa
operated as a completely mixed basir
Peristaltic pumps were used to suppl
wastewater and return sludge to th
aeration basins. PAC slurry was manual!
added twice per day to the front end (
the aeration basin. A peristaltic pum
controlled by a timer wasted sludge froi
the discharge end of each aeration basir
The targeted aeration basin hydraul
retention times (HRT's) and solic
retention times (SRT's) were 2.2 and 1
days, respectively, for all system
During the first test period, 198 and 6J
mg/L of PAC were added to the influen
of Unit 2 and Unit 3, respectively, and
-------
the second test period, 396 and 1,190
mg/L of PAC were added to the influents
of Unit 2 and Unit 3, respectively. Daily
composite samples were taken from the
raw feed wastewater and from the three
clarifier effluents using automatic
sampling equipment, and from the
wasted mixed liquor obtained from the
waste solids holding tanks.
Test Phases-
The planned PACT pilot operation was
scheduled for a series of five phases as
described below:
Phase 1 - Start-up—The three
biological pilot plants were operated for 3
days after being seeded with mixed
liquor from the full-scale aeration
basins. The objective of this phase was
to determine whether the effluents for
each of the three pilot plants were
comparable with respect to SCOD
removal.
Phase 2 - Acc//maf/o/7--Following
Phase 1, PAC addition to the influents
was initiated for Unit 2 and Unit 3 at rates
of 198 mg/L and 698 mg/L, respectively.
Single doses of PAC (as a slurry) were
added to Unit 2 and Unit 3 each day for
the first 4 days to reach the calculated
equilibrium PAC concentration, and the
operation of all three units was continued
for an additional 35 days.
Phase 3 - First Intensive Test
Period—P\\ot plant operation continued
for 14 days with Phase 2 operational
conditions. Intensive sampling was
initiated that included the collection of
aquatic bioassay and organic samples.
Four samples for carbon isotherm testing
were also collected from the control unit
effluent. Daily settling and oxygen uptake
tests were performed on each of the pilot
plant mixed liquors.
Phase 4 - Second Acclimation
Period—This phase lasted 31 days
and was used to increase the PAC
concentrations in the aeration basins for
Unit 2 and Unit 3. The original PAC
doses were increased to 396 mg/L and
1,190 mg/L of raw feed, respectively.
Dver the first four days, additional PAC
was added in slurry form to each
teration basin so as to achieve an
jquilibrium PAC concentration by the
ourth day.
Phase 5 - Second Intensive Test
aeriod-P\\ot plant operation continued
or 14 days with Phase 4 operational
;onditions. Intensive testing was
jerformed similar to that described
jreviously for the first intensive test
period.
Selector Study
The selector pilot unit was operated
over the same time period as the PACT
systems. Unit 1 was used as the control
while Unit 4 was the experimental
selector system.
System Operation--
The selector system was identical to
the control system with the exception
that a series of selector tanks preceded
the aeration basin. Initially, the selector
system consisted of one 7.6 L (2 gal)
anoxic selector tank and two aerated 7.6
L (2 gal) selector tanks operated in
series. The return sludge and feed
wastewater were mixed in the first anoxic
tank and flowed by gravity through the
two aerated tanks and into the 189 L (50
gal) aeration tank. The aerobic selectors
were equipped with an air supply and
metering valves. During the second
phase of the selector study, a third 7.6 L
(2 gal) aerated selector tank was added.
The HRT of each tank was approximately
2 hr based on the raw waste flow.
Test Phases--
Due to the long time required to reach
equilibrium, only two test conditions were
studied.
Phase I - The selector system was
seeded with mixed liquor from the full-
scale plant. The system operation with
respect to sludge settling was monitored
by sludge settling tests. The stirred
sludge volume index (SSVI) was
calculated for the settling tests.
Operation in this mode was continued for
75 days.
Phase II - When the data indicated
the mixed liquor for the selector unit was
not settling much better than the control
unit, a third aerated selector basin, for a
total of four selector basins, was added.
The system was operated with four
basins for the remainder of the study (26
days).
VFMLS Study
It was postulated that the cause of the
VFMLS during the 1984 study was due
to the presence of a material in the
wastewater that was adsorbable and not
readily biodegradable. This material
might have accumulated on the carbon
until it reached a concentration where it
began to act like a high molecular weight
polyelectrolyte and caused the MLSS
and carbon to flocculate and form the
VFMLS.
To test this hypothesis, preliminary
bench tests were conducted in January
at the home laboratory and more tests
were conducted on-site during the pilot
plant study. The basic procedure was to
add spike materials to mixed liquor from
the PACT pilot systems (or mixed liquor
from a conventional activated sludge
system with PAC added for the
preliminary tests), aerate the mixture,
allow the mixed liquor to settle, and
observe the results. This sequence was
then repeated once every 24 hr for the
on-site tests. A total of eight spike
materials were tested at various
concentrations.
Feedwater Quality
Table 1 summarizes the raw waste
characteristics. The raw waste TCOD was
quite variable, ranging from 3,070 to
8,080 mg/L, and it averaged 5,230 mg/L
for 64 samples. This average TCOD was
significantly less than the average TCOD
of the raw wastewater during the 1984
study (7,030 mg/L). Nitrogen and
phosphorous were present in adequate
amounts for biological treatment based
on the effluent concentrations of
phosphorous, ammonia, and
nitrate + nitrite.
Table 1. Summary of Raw
Characteristics
Parameter
TSS, mgIL
TCOD, mg/L
SCOD, mg/L
NIBOD, mg/L
NIS8OD, mg/L
pH, units
Temperature, °C
Average
396 (92)"
5230 (64)
3820 (66)
2700(21)
2200 (20)
-
25.5(112)
Wastewater
Range
90-722
3070-8080
1550-5850
1700-3800
1200-3300
5.9-12.8
(159)
18.0-31.0
"Parentheses indicate number of
observations.
PACT Study
The operational and analytical data
from the first and second intensive test
phases are summarized in Table 2.
During Phase 3, the average HRT and
average SRT values were very close to
the target values and ranged from 2.18 to
2.20 days and 10.0 to 10.1 days,
respectively. The average temperature in
the aeration basins ranged from 35.0 to
36.5°C while the pH ranged from 6.4 to
8.0. The effluent TCOD concentrations
averaged 654, 413, and 344 mg/L for
Units 1, 2, and 3, respectively, while the
effluent SCOD concentrations averaged
498, 364, and 220 mg/L, respectively.
The average HRT and SRT values
ranged from 2.18 to 2.20 days and 10.0
to 10.4 days, respectively, during Phase
5. The pH ranged from 7.3 to 8.1 and the
-------
Table 2. Average Operational Parameters and Effluent Quality During the Intensive Test Periods
Phase 3 Phase 5
Day 43-56 Day 88-101
Unit 1
Unit 2 Unit 3
Unit 1
Unit 2 Unit3
Operation Data
Feed Flow, mUm'm
PAC Dosage, mgIL Feed-
Return Sludge Flow, mUmin
Waste Mixed Liquor Flow, Uday
F/M, g TCOD/dayg MLSS"
HRT, days
SRT, days
60.0
0
60.1
17.7
0.58
2.19
10.0
60.3
198
63.5
18.6
-
2.18
10.0
59.9
698
61.2
15.6
-
2.20
10.1
59.8
0
176
17.7
0.54
2.20
10.4
60.2
396
203
18.2
-
2.18
10.1
60.3
1190
59.5
18.7
-
2.18
10.0
Mixed Liquor Data
Temp.,°C
pH (range)
Dissolved Oxygen, mgIL
TSS, mg/L
SSVI, mUg"
Effluent Data
TCOD, mg/L
SCOD, mg/L
NIBOD, mg/L
NISBOD, mgIL
rSS, mg/L
VSS, mg/L
Removals
Average Feed TCOD, mg/L
Average Feed SCOD, mg/L
TCOD Removal, %
SCOD Removal, %
36.5
6.5-8.0
2.7
4030
229
35.0
6.4-7.8
2.4
5620
144
35.0
6.5-7.7
2.0
8050
58.3
34.5
7.4-8.1
2.5
4870
194
35.0
7.3-8.0
2.2
7780
107
36.0
7.3-8.0
1.7
11600
53.0
654
498
11
6
77
63
413
364
6
<4
20
17
5030 5030
3480 3480
86.7 91.6
85.5 89.4
344
220
9
6
728
123
5030
3480
92.9
93.6
532
449
13
4
39
34
5690
4210
90.5
89.1
244
210
7
<3
23
22
164
127
<4
<3
20
18
5690 5690
4210 4210
95.6 97.1
94.9 96.9
"Food to microorganism ratio.
"Stirred sludge volume index.
-Not determined.
average temperature ranged from 34.5 to
36.0°C in the aeration basins over the
Phase 5 test period. Average effluent
TCOD concentrations for Phase 5 were
532, 244, and 164 mg/L, for Units 1, 2,
and 3, respectively, and average effluent
SCOD concentrations were 449, 210, and
127 mg/L, respectively.
The addition of PAC resulted in some
improvement in MLSS settling rate as the
SSVI data in Table 2 indicates. However,
problems with floating sludge in the
clarifiers, especially Unit 2, were
encountered. The large PAC dosages
added to Unit 3 resulted in a consistently
good settling sludge.
rCOO and SCOD Removal
The addition of PAC to the activated
sludge process improved the removal of
both TCOD and SCOD. The comparison
of the two intensive test phases was
complicated by the different raw
wastewater characteristics for the two
phases. The influent TCOD and SCOD
values were greater for Phase 5 than
Phase 3 but the control unit effluent
TCOD and SCOD concentrations were
less during Phase 5 than Phase 3. Thus,
the Phase 3 698 mg/L PACT unit
average effluent SCOD concentration
(220 mg/L) was slightly greater than the
Phase 5 396 mg/L PACT effluent SCOD
concentration (210 mg/L). The average
SCOD removal percentage of the 396
mg/L PACT unit (94.9%) was also
slightly greater than the 698 mg/L PACT
unit (93.6%).
Carbon adsorption isotherm tests
were performed on four control unit
effluent samples from each of the two
intensive test phases. All eight of the
tests were combined to produce a single
isotherm plot. The line of best fit for the
data is as follows:
M = PAC dosage, g/L
Ce = equilibrium effluent SC<
concentration, mg/L
The SCOD data from the PA
systems can also be presented or
Freundlich plot. It was assumed that
additional SCOD removal by the PA
systems compared to the control wh
was operated in parallel vv
accomplished by the PAC. This allowe
calculation of the amount of SC
removed per unit of carbon added in
SCOD per gram of PAC. The data <
evaluated with the resulting line of t
fit:
(2)
— =(0.80)CU4
M e
d)
where:
X = amount of SCOD removal
attributed to the PAC, mg/L
Figure 1 compares the isothc
derived from the pilot plant results
that derived from the jar tests. In
case both isotherms are very sim
which suggests that isotherms deriv
from the jar tests would provide a £
prediction of the PAC requirement:
-------
Combined Jar Tests
X _
M
Carbon Adsorption Isotherm
Freundlich Equations
Pilot Plant Results
M
10000
1000
g
1
8
r
I
100
10
f lot Plant Data
•+•
4
Combined Jar Test Results .
11
10
100 1000
Ce (SCOD), mg/L
10000
Figure 1. Comparison of the isotherm derived from the pilot plant results with that derived
from the combined jar tests.
produce any desired effluent SCOD
joncentration (down to Ce - \27 mg/L).
"he similarity between the adsorption
sotherms also suggests that there was
10 enhanced biodegradation of refractory
;ompounds in the PACT systems.
Specific Organic Compounds
Removal
Based on preliminary samples of raw
/astewater and the plant raw product list,
ight compounds were selected for
uantification using GC/MS techniques
)r intensive test samples. In addition,
omputer searches to tentatively identify
and quantify all detected peaks were
completed. Of the six volatile compounds
analyzed for (total xylenes, ethyl
benzene, acetone, acrylonitrile,
methylene chloride, and ethyl acetate),
only two effluent samples and one waste
mixed liquor sample contained
quantifiable amounts of any of the six
compounds. No differences between the
control and PACT units with respect to
removal of these compounds or
concentration of these compounds in the
waste sludges were found.
Two semivolatile compounds, alpha-
picoline and dicyclohexylamine, were
specifically quantified in all samples.
Alpha-picoline was found more
frequently in Unit 1 (7 of 8) waste mixed
liquor samples than Unit 2 (6 of 8) or Unit
3 (4 of 8) and in higher concentrations.
However, with the exception of one
control sample with 1,600 ng/L and one
control sample with 84 ng/L all samples
were below 50 pg/L. Alpha-picoline was
found in 7 of 8 control unit effluent
samples but not in any effluent samples
from either PACT unit. Thus alpha-
picoline was slightly higher in the control
effluent samples as well as the waste
mixed liquor samples. All of the control
effluent samples contained less than 30
of alpha-picoline, however.
-------
Dicyclohexylamine was found in 7 of 12
waste mixed liquor samples from the
second intensive test period but was not
measured in any samples during the first
period. The concentrations were
somewhat higher (up to 700 ng/L) in the
control samples than the PACT samples
(up to 150 pg/L). Dicyclohexylamine was
only found in one effluent sample (Unit 1
at IIOng/L).
A wide variety of compounds were
identified in the computer searches of
the effluent and waste mixed liquor
samples. However, there was no
apparent relationship between PAC
concentration and tentatively identified
volatile organic compounds in either the
effluents or waste mixed liquors.
The TCLP analysis of the waste mixed
liquors determined that none of the
samples analyzed would be classified as
toxic as defined under proposed U.S
EPA hazardous waste identification
regulations (40 Code of Federal
Regulations 261.24). No organic
compounds were detected in any of the
samples.
Aquatic Toxicity Removal
Bioassays of the samples from the
first intensive test period did not show
any significant difference in toxicity
removal between the control and PACT
units. The average acute (C. dub/a)
toxicity (medium lethal concentration,
LCgo) of the effluent samples was 46%,
51%, and 47% for Unit 1, Unit 2 and Unit
3, respectively, while the average toxicity
of the raw waste was 0.81%. There was
also no obvious differences between the
chronic toxicity of the various pilot plant
effluent samples.
The average LCso of the raw waste for
Phase 5 was 1.0%, which was similar to
the Phase 3 LC$Q. The effluent samples
from the second intensive test period,
however, were more toxic than from the
first test period. The average LCgo
values from Unit 1, Unit 2, and Unit 3
were 14%, 5.8%, and 0.82%. The data
for Phase 5 indicate that the toxicity
appeared to increase with increasing
PAC concentrations. Only limited chronic
toxicity data were obtained due to
problems experienced with the bioassay
test procedure.
Selector Study
The selector unit was operated to
determine if improvements in the settling
characteristics of the mixed liquor could
be achieved. The selector unit mixed
liquor showed some improvement in
settling characteristics as measured by
the SSVI test when compared to the
control over the entire Phase I test
period. The average SSVI values over
Phase I were 222 and 163 mL/g for Unit
1 (control unit) and Unit 4 (selector unit),
respectively. The selector unit mixed
liquor SSVI, however, was equal to or
greater than the control unit values for
most of Phase II. During Phase II, Unit 1
and Unit 4 SSVI's averaged 194 and 208
mL/gm, respectively. The most obvious
difference between the two phases
(besides the additional selector basin
added for Phase II) was that the DO
concentrations in the selector basins
were generally lower during Phase II as
compared to Phase I. This observation,
along with the presence of
Haliscomerobacter hydrossis found in
the microscopic examination, suggests
that the lack of DO in the selector basins
was the cause of the poor settleability of
the selector mixed liquor. Pure oxygen
was used for the last 6 days of operation
of Phase II, and the SSVI tests
performed during this period indicated
some improvement in settling of the
mixed liquor.
VFMLS Study
None of the bench tests completed in
January, May, or June 1987 resulted in
the formation of a VFMLS. Either the
individual spike materials tested were not
the cause of the original VFMLS or the
proper conditions for the formation of the
material were not simulated in the bench
tests. The task of recreating the VFMLS
was made difficult by the fact that the
product mix at the plant changes, which
results in variable wastewater
characteristics. It is possible that a
unique pharmaceutical wastewater matrix
existed during the 1984 study that did
not exist during this study.
Conclusions
The pilot study project conclusions
are summarized below:
1. Efforts to identify the cause of the
VFMLS that formed during the 1984
study were unsuccessful.
2. Effluent SCOD concentrations were
significantly reduced by the addition
of PAC to the activated sludge
system when compared to the
control unit. For the first intensive
test phase, effluent SCOD
concentrations were reduced by
26.9% and 55.8% compared to the
control unit effluent SCOD when
adding 198 mg/L and 698 mg/L of
PAC, respectively. Effluent SCOD
concentrations were 53.2% and
71.7% lower than the control unit
value when 396 mg/L and 1.19(
mg/L of PAC were added
respectively.
3. Isotherms derived from this plant';
wastewater treatment plant effluen
are a good predictor of the PAC
requirements to produce any desirei
effluent SCOD concentration (at leas
down to Ce = 127 mg/L) by thi
following equation:
M
= (0.80)CL14
4. PAC addition improved the settlin
characteristics of the MLSS
However, all three system
experienced floating and bulkin
sludge during the study.
5. There was no significant difference i
the removals of acetone, acrylonitrih
methylene chloride, ethyl acetati
ethyl benzene, total xylenes, alphi
picoline, and dicyclohexylamin
between the control unit and tf
PACT units.
6. Effluent aquatic toxicity was n<
reduced by the PACT systems ar
in some cases the PACT effluen
were apparently more toxic than tt
control unit effluents as measured t
the acute test. The effluents we
substantially more toxic for tt
second intensive test period i
compared to the first as measun
by the acute toxicity test.
7. The study did not show ai
correlation of COD with aqua'
toxicity, BOD, or specific identifial
organic compounds in th
pharmaceutical wastewater.
8. The TCLP analyses of the cont
and two PAC units' mixed liqi
samples did not identify a
contaminants above the regulat
limits.
9. The selector unit mixed liquor settl
somewhat better than the control i
mixed liquor at certain times but :
exhibited filamentous bulki
characteristics. The presence of
filamentous organism Haliscome
bacter hydrossis in one selec
mixed liquor sample collected dur
the second intensive test per
suggested there was a shortage
dissolved oxygen in the selec
basins. A shortage of dissoh
oxygen may have contributed to
failure of the selector system
control the growth of filament
organisms during this period of tir
-------
The full report was submitted in
fulfillment of Contract Number 68-03-
3371 by Radian Corporation under the
sponsorship of the U.S. Environmental
Protection Agency.
-------
David A. Gardner and Richard A. Osantowski are with Radian Corporation,
Milwaukee. Wl 53214.
Clyde Dempsey is the EPA Project Officer (see below).
The complete report consists of two volumes, entitled "Evaluation of Biological
Treatment of Pharmaceutical Waste wafer with PAC Addition:"
Volume I: (Order No. PB 88-212 527/AS; Cost: $25.95, subject to change)
Volume II: (Order No. PB 88-212 5351 AS; Cost $32.95, subject to change
The above reports will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Water Engineering Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
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