6EPA
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
EPA-600/7-78-209
November 1978
Field and Laboratory
Studies for the
Development of Effluent
Standards for the Steam
Electric Power Industry
Interagency
Energy/Environment
R&D Program Report
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
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This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from the
effort funded under the 17-agency Federal Energy/Environment Research and
Development Program. These studies relate to EPA's mission to protect the public
health and welfare from adverse effects of pollutants associated with energy sys-
tems. The goal of the Program is to assure the rapid development of domestic
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essary environmental data and control technology. Investigations include analy-
ses of the transport of energy-related pollutants and their health and ecological
effects; assessments of, and development of, control technologies for energy
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EPA REVIEW NOTICE
This report has been reviewed by the participating Federal Agencies, and approved
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This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/7-78-209
November 1978
Field and Laboratory Studies
for the Development of Effluent
Standards for the Steam Electric
Power Industry
by
Frank G. Mesich and Milton L Owen
Radian Corporation
P.O. Box 9948
Austin, Texas 78766
Contract No. 68-02-2608
Task No. 22
Program Element No. EHE624A
EPA Project Officer: Theodore G. Brna
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
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ABSTRACT
Carbon absorption, chemical precipitation, reverse
osmosis and vapor compression distillation (VCD) were evaluated
as removal technologies for priority pollutants from wastewater
streams of utility power plants. These technologies, except
VCD, were tested in bench-scale systems for the removal of
priority pollutants from cooling tower blowdown and ash pond
effluent at three coal-fired plants. The removal of organic
pollutants by activated carbon and reverse osmosis and inorganic
pollutants by chemical precipitation and reverse osmosis was
evaluated at these plants. An operational VCD unit handling a
combined waste stream was tested for the removal of both organic
and inorganic pollutants at a fourth coal-fired plant. Samples
of plant make-up water, cooling tower blowdown and ash pond
effluent plus effluent waters from the treatment technologies
were analyzed for priority organic and inorganic pollutants.
Only eleven priority pollutants, of which eight were
inorganic pollutants, were measured in concentrations greater
than 10 ppb, and none of these were common to all the plants
studied. Carbon absorption and reverse osmosis demonstrated
some removal of priority organic pollutants, but the low con-
centrations observed prevented definitive conclusions on their
removal effectiveness. Chemical precipitation, reverse osmosis,
and vapor compression distillation effectively decreased the
inorganic compounds including arsenic, copper and lead, all of
which were present in significant concentration levels in at
least one wastewater stream.
iii
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CONTENTS
Page
Abstract iii
Figures vi
Tables vii
Acknowledgments x
1. Introduction ( 1
2. Conclusions and Recommendations 3
3. Results 5
3.1 Procedure 5
3.2 Summary of Data 9
3.2.1 Water Samples for Plant Intake and
Wastewater Streams 9
3.2.2 Results of Treatment by Activated
Carbon 12
3.2.3 Results of Treatment by Chemical
Precipitation 12
3.2.4 Results of Treatment by Reverse Osmosis. 15
3.2.5 Results of Vapor Compression Distilla-
tion Performance 18
4. Plant Characterization and Sampling Locations 19
4.1 Plant Water/Wastewater Characterizations and
Location of Sample Points 19
4.1.1 Plant 5604 19
iv
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CONTENTS (Continued)
Page
4.1.2 Plant 1226 25
4.1.3 Plant 5409 2S
4.1.4 Plant 3009 32
5. Chemical Analysis of Untreated Water Samples 37
5.1 Organic Compounds 37
5. 2 Inorganic Compounds 47
6. Control Evaluation 55
6.1 Activated Carbon 57
6.2 Chemical Precipitation 62
6.2.1 Lime Precipitation 62
6.2.2 Lime Plus Ferrous Sulfate Precipitation. 67
6.2.3 Lime Plus Ferric Sulfate Precipitation-. 71
6.2.4 Lime Plus Sodium Sulfide Precipitation.. 72
6.3 Reverse Osmosis 73
6.3.1 Organic Analysis 74
6.3.2 Inorganic Analysis 81
6.4 Vapor Compression Distillation 86
6.4.1 Organic Analysis 87
6.4.2 Inorganic Analysis 87
References 91
Appendix A-
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FIGURES
Number Page
4-1 General water flow diagram of water/wastewater
system for Units 1, 2, and 3 of Plant 5604 22
4-2 General water flow diagram of water/wastewater
system for Unit 4 of Plant 5604 23
4-3 General flow diagram of plant water/wastewater
system for Plant 1226 27
4-4 Plant 5409 water/wastewater system 29
4-5 Plant 3009 water flow scheme 33
4-6 Vapor compression distillation unit 34
vi
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TABLES
Number Page
3-1 Priority Pollutants Identified in Plant Water
Steams 1°
3-2 Summary of Activated Carbon Performance for
Organic Compounds 13
3-3 Summary of Chemical Precipitation Performance for
Inorganic Compounds 14
3-4 Summary of Reverse Osmosis Performance for Organic
Compounds 16
3-5 Summary of Reverse Performance for Inorganic
Compounds 17
4-1 Summary of Plant Characteristics 20
4-2 Cooling Tower Operating Data for Plant 5409 30
5-1 Plant 5604: Organic Analyses of Raw Water Samples
by Gas Chromatography 39
5-2 Plant 5604: Organic Analysis of Raw Water Samples
by Gas Chromatography -.Mass Spectrometry 40
5-3 Plant 1226: Organic Analyses of Raw Water Samples
by Gas Chromatography 41
5-4 Plant 1226: Organic Analysis of Raw Water Samples
by Gas Chromatography - Mass Spectrometry....... 42
5-5 Plant 5409: Organic Analyses of Raw Water Samples
by Gas Chromatography 43
5-6 Plant 5409: Organic Analysis of Raw Water Samples
by Gas Chromatography - Mass Spectrometry 45
5-7 Plant 5604: Inorganic Analysis of Raw Water
Samples 48
vii
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TABLES (Continued)
Number Page
5-8 Plant 1226: Inorganic Analysis of Raw Water
Samples 49
5-9 Plant 5409: Inorganic Analysis of Raw Water
Samples 50
5-10 Plant 3009: Results of Inorganic Analysis for
Inlet Water to Vapor Compression Distillation
Unit 51
6-1 Plant 5604: Removal of Organic Compounds by
Activated Carbon. . . .< 58
6-2 Plant 1226: Removal of Organic Compounds by
Activated Carbon 59
6-3 Plant 5409: Removal of Organic Compounds by
Activated Carbon 60
6-4 Plant 5604: Inorganic Removal Efficiencies
for Lime Precipitation 63
6-5 Plant 1226: Inorganic Removal Efficiencies for
Lime Precipitation 64
6-6 Plant 5409: Inorganic Removal Efficiencies for
Lime Precipitation 65
6-7 Plant 5604: Inorganic Removal Efficiencies for
Lime Plus Ferrous Sulfate Precipitation 68
6-8 Plant 1226: Inorganic Removal Efficiencies for
Lime Plus Ferrous Sulfate Precipitation 69
6-9 Plant 5409: Inorganic Removal Efficiencies for
Lime Plus Ferrous Sulfate Precipitation 70
6-10 Plant 5604: Removal of Organic Compounds by
Reverse Osmosis 75
6-11 Plant 1226: Removal of Organic Compounds by
Reverse Osmosis 77
V13.1
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TABLES (Continued)
Number Page
6-12 Plant 5409: Removal of Organic Compounds by
Reverse Osmosis 79
6-13 Plant 5604: Inorganic Compound Removal
Efficiencies for Reverse Osmosis 82
6-14 Plant 1226: Inorganic Compound Removal
Efficiencies for Reverse Osmosis ... 84
6-15 Plant 5409: Inorganic Compound Removal
Efficiencies for Reverse Osmosis 85
6-16 Plant 3009: Removal of Organic Compounds by
Vapor Compression Distillation 88
6-17 Plant 3009: Inorganic Compound Analysis of Water
Samples from the VCD Unit 89
ix
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ACKNOWLEDGMENTS
The breadth of this study is such that it would be
impossible to thank everyone who contributed individually. The
authors express their appreciation to T. G. Brna and J. W. Lum
of the Environmental Protection Agency for their guidance in
performing this study. We would also like to thank Pacific
Power & Light Company; Gulf Power Company, Appalachian Power
Company, Montana Power Company, and their staffs at the parti-
cipating power stations, who'se cooperation and support greatly
facilitated this work. The cooperation of Edison Electric
Institute and the Utility Water Act Group in assisting in iden-
tifying and gaining access to the plants for field testing is
greatly appreciated. We extend our gratitude to the various
process vendors and developers who lent their time and resources
to supply information and discuss questions relating to the
program.
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SECTION 1
INTRODUCTION
The development and refinement of effluent limitations
for the utility industry under the 1977 Clean Water Act Amend-
ments places significant emphasis on the "priority" pollutants,
some 129 compounds or species requiring removal from water efflu-
ents. The data concerning the presence and levels of these
species in utility effluents, are limited. However, based on pre-
liminary data, several technologies have been identified which
would potentially remove the priority pollutants at very low
levels (Reference 1). Field data concerning the application of
treatment technology to utility wastes were needed to establish
whether treatment of dilute wastes is technologically feasible.
This report describes the results of bench-scale field
tests conducted to evaluate the technical feasibility of re-
ducing priority pollutants in utility wastewater streams. The
following four processes were selected as having the highest
potential for pollutant control based on a previous EPA study
(Reference 1):
Carbon adsorption
Chemical precipitation
Reverse osmosis
Vapor compression distillation
Selection of these processes was based on several factors. Car-
bon adsorption is known to be effective for removal of organic
materials at higher concentration levels than those generally
-------
observed in utility effluents. Similarly, chemical precipi-
tation, i.e., lime or slufide, is practiced for the removal
of high levels of trace elements. Reverse osmosis (RO) shows
promise as a pretreatment step which produces a waste stream
with concentrations in the range handled by conventional tech-
nology (i.e., reverse osmosis in conjunction with other treat-
ments may effectively handle utility wastes). Vapor compression
distillation (VCD) was selected because, although the technology
is practiced effectively, no substantive information is available
concerning the secondary pollution of VCD sludge or air emissions,
Bench-scale tests of carbon adsorption, chemical pre-
cipitation, and reverse osmosis were conducted at three coal-
fired power stations to evaluate their performance in treating
cooling tower blowdown and ash pond effluent. An operational
vapor compression distillation unit processing plant wastewaters
at a fourth coal-fired power station was sampled for secondary
emissions. The results of the field tests and the procedures
used in the evaluation are presented in the following sections
of this report.
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SECTION 2
CONCLUSIONS AND RECOMMENDATIONS
The following conclusions resulted from the field
evaluation of the performance of carbon adsorption, chemical
precipitation, reverse osmosis and vapor compression distilla-
tion for the removal of priority pollutants from the wastewater
streams of utility power plants.
The wastewater streams at the power plants
studied contained very low concentrations
of priority pollutants. Only three organic
and eight inorganic priority pollutants
were measured in concentrations greater
than 10 ppb. None of these compounds were
consistently observed at concentrations
greater than 10 ppb at all of the plants
sampled.
Within analytical ability to detect the
low concentration levels, carbon adsorp-
tion and reverse osmosis significantly
reduced the organic compound levels.
Reverse osmosis and vapor compression
distillation were effective in concentrating
the priority pollutants in a wastewater
stream and produced a clean water stream
suitable for recycle.
Chemical precipitation, reverse osmosis
and vapor compression distillation were
effective for the removal of inorganic
compounds at the concentration levels
encountered at the utility power plants.
For arsenic, copper, and lead, lime pre-
cipitation and reverse osmosis demonstrated
removal efficiencies greater than 50% when
inlet concentrations are above 20 ppb.
For the removal of selenium, reverse osmosis
-------
demonstrated a greater effectiveness than
lime precipitation, 85 percent removal as
compared to 24 percent. Vapor compression
distillation effectively removed all
priority inorganics with the exception of
vanadium.
Little information concerning the presence, levels
and frequency of occurrence of a number of priority pollutants
in coal-fired power plants is available. Additional sampling
by EPA under the Effluent Guidelines Division screening and ver-
ification analysis efforts should provide an adequate data base
to supply this information.
Subsequent sampling and analysis efforts may identify
priority pollutants occurring in concentrations requiring
treatment. If this occurs, then further testing is warranted.
The technologies examined in this study show sound potential
which should be demonstrated on a pilot scale. At this stage,
sufficient data would be developed to closely define treatment
efficiency, practical operating parameters, and economics of
installation for new plant and retrofit applications.
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SECTION 3
RESULTS
The basic procedure followed to perform this study is
presented in the first part of this section. A more detailed
explanation of the test plan and analytical procedures is pre-
sented in the Appendix. A summary of results is presented at
the end of the section.
<
3.1 PROCEDURE
The procedures for conducting the study can be
divided into seven steps. These steps are listed below and an
explanation of the objectives and procedures associated with
each one follows.
1. Selection of technologies for evaluation
2. Selection of coal-fired power plants for
sampling purposes
3. Development of test plans and field
sampling procedures
4. Development of analytical procedures
for laboratory analyses
5. Actual field testing of treatment
technologies
-------
6. Analyses of water samples
7. Interpretation of results
The first four steps involve the selection and con-
ceptual development work associated with the project. The first
step, selection of technologies, was provided by an earlier
study, "Assessment of Technology for Control of Toxic Effluents
from the Electric Utility Industry"( EPA Contract No. 68-02-
2608, Work Assignment 9). Control technologies that showed the
greatest promise for removing trace quantities of organic and
inorganic priority pollutants from utility wastewaters were
selected.
The second step involved selection of power plants as
locations for conducting the field testing. The primary objec-
tive was to select plants known to, or likely to, contain at
least some of the priority pollutants. With the assistance of
the Utility Water Act Group (UWAG), Edison Electric Institute
and other industry personnel, four plants were selected for test-
ing based on plant operations and effluent compositions.
Concurrent with the efforts of selecting appropriate
plant sites for testing, development of test plans for both
laboratory and field testing was accomplished. The primary ob-
jective was to devise field evaluation plans for bench-scale
systems that would answer the basic questions of the suitability
of the chosen technology for removing the priority pollutants.
No previous studies covering the types of compounds at the con-
centration levels expected were available to aid in the
-------
development of the evaluation plans. An essential element of
the evaluation plans was that the field tests for each technolo-
gy be simple and direct.
The problems of preserving sample integrity were eval-
uated to ensure that the analyses conducted at the laboratory
accurately reflected the composition of the sample as it was
collected in the field. To accomplish this, measures had to be
taken to prevent sample contamination, chemical reaction and
losses due to compound volatility. Several steps were taken to
provide this assurance, such as prevention of any contamination
from the materials used for sfample collection, purging and
collection of volatile organics in the field, and stabilization
of samples by refrigeration and sample preparation. Once a com-
plete set of procedures for each type of chemical analysis was
developed, it was possible to begin the field evaluation.
For each sample taken, both organic and inorganic
analysis was performed. Organic analysis was accomplished by
use of both gas chromatography and gas chromatography-mass
spectrometry. The plant inlet, cooling tower blowdown (CTB)
and ash pond effluent (APE) samples were analyzed by gas
chromatography-mass spectrometry to positively identify the
presence of a compound. The faster and more economical gas
chromatography was used to analyze the treated and untreated
streams to evaluate the effectiveness of technologies for
reducing pollutants. Evaluation of the success of treatment
was based only on those compounds positively identified as
present in the inlet streams. Most of the inorganic compounds
were analyzed by atomic absorption. Selenium was analyzed by
fluorometry and cyanide by a colorimetric procedure.
-------
The field testing involved on-site sampling and
demonstration of the treatment technologies. The equipment was
loaded into a 40-foot trailer containing all the support equip-
ment and laboratory space needed to perform the necessary field
tasks. The chemical precipitation tests and activated carbon
tests were performed in the trailer. The inlet wastewater
samples from the cooling tower and ash pond were collected in
large glass bottles that had been properly prepared to prevent
contamination. The wastewater samples to be used as feed to
the treatment technologies were analyzed for the complete list
of priority pollutants. These analyses were used to determine
the quality of the wastewater prior to treatment.
The reverse osmosis unit was operated at the sampling
point and run for at least one hour prior to sampling of its
outlet streams. During this time pH and conductivity measure-
ments were taken for the inlet, the product and the reject
stream. When these parameters reached steady-state, the sam-
pling was performed.
The samples of the treated and untreated wastewater
were collected, stored and shipped to the home laboratories.
In the case of the purgeable organics, the samples were purged
in the field to collect the organics prior to shipment.
The final step in the procedure was the analysis of
the results. The development of detection limits and error
limits was an important factor in analyzing the results and
is explained in detail in the Appendix.
NUS Corporation, on behalf of UWAG, collected dupli-
cate samples during the project testing and sampling. It is
expected that those results will be available in the future
for comparison.
8
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3.2 SUMMARY OF DATA
A brief summary of the results of the study is
presented in this section. The detailed results are presented
in Section 6. A list of compounds observed in the plant inlet,
the cooling tower blowdown and the ash pond effluent at the
plants tested is presented. The results of testing the treat-
ment technologies for removing the observed compounds in the two
wastewater streams are presented. The results of the evaluation
of the vapor compression distillation unit are presented last.
3.2.1 Water Samples for Plant Intake and Wastewater Streams
The compounds and concentrations observed at the three
plants testing carbon adsorption, reverse osmosis, and chemical
precipitation are presented in Table 3-1. The summary of organ-
ic compounds includes only those observed by gas chromatography
and confirmed by gas chromatography-mass spectrometry. The
concentration levels are those produced by gas chromatography
analysis. A concentration preceded by "<" designates the detec-
tion limit for a compound which was identified but was present
at a concentration too small to be quantified. A blank in the
table signifies the compound was not identified as being present.
For comparison purposes, the EPA drinking water stan-
dards are presented in the table. Of the 29 concentrations of
organic compounds presented in Table 3-1 (the phthalates are not
included due to sample contamination). only those for dibromo-
chloromethane, bromoform and toluene are greater than 10 ppb.
For Plant 5409, more compounds were detected in the plant intake
than were detected in the cooling tower blowdown and ash pond
effluent.
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TABLE 3-1. PRIORITY POLLUTANTS IDENTIFIED IN PLANT WATER STREAMS (ppb)
Organlce*
BronodlchloroBethane
Dibronochloranethane
Chloroforn
Broaoform
Carbon tetrachlorlde
Trichloroethylene
Benzene
Toluene
1.3/1,4-Dichlorobenzene
1 . 2-Dlchlorobenzene
Plant Intake
Plant Plant Plant v
5604 1226 5409
1.4
<1.0
<4.0
1.2 2.4
'9.1 2.0
2.4/3.5
5.3
Cooling tover bloudown
Plant Plant Plant
5604 1226 5409
8.2 2.6
58. 5 <1.0
<1.0 2.4
154
<4.p
1.5
23.5
Ash pond effluent
Plant Plant Plant EPA drinking1
5406 1226 5409 water standarde
100e
<1.0 100°
f
<1.0 0.5
<1.0 0.5f
0.5f
0.5'
2.0 1.0
3.5 <1.0
0.5
0.5
Utility
Irrigation industry
standards BATEA
.
Ble(2-ethyl-hexyl) phthalate*
or Benz(a)anthracene
or Chryaene
Dlethyl phthalata
Butyl benzyl phthulatc
Dl-n-butyl phthalate
Phenol
6.6
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TABLE 3-1. (Continued)
Plant Intake
Inorganics*
Antimony
Arsenic
Beryllium
Cadmium
Chromlua
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Plant
5604
It
<1
<0.5
<0.5
<2
700
6
<0.2
< .5
<2
3
<1
11
53
Plant
1226
7
3
<0.5
2.1
7
12
10
0.4
l.S
<2
1.3
<1
40
9
Plant
5409
3
<1
<0.5
1.4
<2
27
8
<0.2
1.7
<2
1.6
<1
13
15
Cooling
Plant
5604
5
7
<0.5
<0.5
<2
180
<3
<0.2
6.0
<2
3
<1
24
780
toner blowdown
Plant Plant
1226 5409
7
4
<0.5
1.8
5
47
3
0.2
6.0
<2
0.7
<1
27
26
<1
35(<1)
3.4
0.8
37
3800(620)
130(70)
0.5
4.0
<2
14
8
11
290(61)
Ash pond effluent
Plant
5406
6
<1
2.5
1.0
4
80
<3
<0.2
9.5
3
5.5
1
-27
300
Plant
1226
7
9
<0.5
2.0
6
14
4
<0.2
5.5
8 A
0.5
1
78
7
Plant
5409
5
74
<0.5
<0.5
<2
26
<3
<0.2
2.5
42
1.0
9
31
11
EPA drinking*"
water standards
50
10
50
1000
50
2
10
50
5000
Irrigation
standards
1000
100
10
100
200
5000
200
20
-
2000
Utilityd
Industry
BATEA
200
1000
1000
Organic analysis by gas chronatography and confirmed presence by CC-HS.
bFederal Register, 24 December 1975 and 31 March 1977.
'Reference 2.
Reference 3.
'Total Trlhalonethanea.
After treatment by granular activated carbon.
"phthalatea cannot be quantified due to sample contamination. * indicates compound identified.
( ) Parentheses indicate concentration of dissolved fraction.
< - Designates concentration below detection limit.
-------
The inorganics identified at the three plants are
presented at the bottom of the table. As was done for the or-
ganic compounds, any concentration preceded by "<" designates
a compound or element present below its detection limit. For
comparison purposes, the EPA drinking water standards, as well
as irrigation standards and current best available technology
economically achievable (BATEA) regulations for the industry,
are presented. Only arsenic, copper, lead, and selenium exceed
any of the standards. These standards are presented only for
comparison purposes; they do not represent proposed standards
for priority pollutants at utility power plants.
3.2.2 Results of Treatment by Activated Carbon
The results of the chemical analysis for the inlet
and outlet streams of the activated carbon column are summarized
in Table 3-2. In 8 cases out of 20, a compound was identified
in the inlet at a concentration greater than the detection limit.
In only two cases, both for toluene, did the effluent contain a
compound at a concentration greater than the detection limit.
For the most part, observed removal efficiencies were greater
than 50%. However, it should be noted that at such very low
inlet concentrations, the lack of detection in the outlet and
the correspondingly high removal efficiencies are not unusual.
3.2.3 Results of Treatment by Chemical Precipitation
The results of the chemical analyses for selected
inorganics in the influent and effluent samples for lime precipi-
tation are presented in Table 3-3. The table also contains the
results of treating cooling tower blowdown and ash pond effluent
with lime and with lime plus ferrous sulfate. The results for
12
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TABLE 3-2. SUMMARY OF ACTIVATED CARBON PERFORMANCE
FOR ORGANIC COMPOUNDSa
Compound
Inlet
concentration
(ppb)
Outlet
concentration
(ppb)
Observed removal
efficiency
(5)
Benzene
Plant 5604 (CTB)C 50
Plant 5409 (CTB) 1.5 33
Plane 5409 (APE) <1 <1
Toluene
Plane 5604 (CTB) 23.5 3.0 87
Plant 5604 (APE) 3.5 7.0 —
Plant 5409 (APE) <1 —
Ethylbenzene ,
Plant 5604 (APE) <1 <1 —
Chloroform
Plant 5604 (APE) <1
Plant 1226 (CTB) <1 —
Plant 5409 (CTB) 2.4 >58
Plant 5409 (APE) <1 88
Plant 5409 (CTB) 2.6 >62
Dibromochlororaethane
Plant 1226 (CTB) 58.5 >98
Plant 1226 (APE) <1 —
Plant 5409 (CTB) <1 —
Bromoform
Plant 1226 (CTB) 154 >99
Plant 1226 (APE) <1 —
Trichloroethylene
Plane 5409 (CTB) <4 —
aA blank in the column signifies the compound was not identified as being
.present.
< - Designates concentration below detection liai:
jCTS - Cooling tower blowdown
APE - Ash pond effluent
13
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TABLE 3-3.
SUMMARY OF CHEMICAL PRECIPITATION PERFORMANCE
FOR INORGANIC COMPOUNDS (Lime/lime plus
ferrous sulfate)a
Inlet Outlet Observed removal
concentration concentration efficiency
Compound (ppb) (ppb) (Z)
Arsenic
Plant 5604 (CTB)C
Plane 5604 (APE)d
Plane 1226 (CTB)
Plane 1226 (APE)
Plant 5409 (CTB)
Plant 5409 (APE)
Copper
Plant 5604 (CTB)
Plant 5604 (APE)
Plant 1226 (CTB)
Plant 1226 (APE)
Plant 5409 (CTB)
Plant 5409 (APE)
Lead
Plant 5604 (CTB)
Plant 5604 (APE)
Plant 1226 (CTB)
Plant 1226 (APE)
Plant 5409 (CTB)
Plant 5409 (APE)
Selenium
Plane 5604 (CTB)
Plant 5604 (APE)
Plant 1226 (CTB)
Plane 1226 (APE)
Plant 5409 (CTB)
Plant 5409 (APS)
.Separates values for lime
7
4
9
<1
75
180
80
47
14
620
26
<3
<3
<3
4
70
<3
<2
3
<2
8
<2
42
and lime plus
«/d
3/3
86/>86
25/25
>89/67
1
>99/>99
73/86
71/71
62/>91
29/50
89/92
54/31
— / —
— /—
— /—
>25/>25
>96/>96
— /—
__ I
0/0
/
0/13
— /24
suliate respectively
< - Designates concentration is belov detection limit
jCT3 - Cooling tower blowdown
APE - Ash pond effluent
14
-------
arsenic, copper, lead, and selenium are presented because of
their relatively high concentration in at least one wastewater
stream.
In general, chemical precipitation using lime was very
effective for reducing these compounds. The notable exception
was selenium. Ferrous sulfate was added with lime to evaluate
coprecipitation as a mechanism for reducing inorganics. For
the cases studied, lime plus ferrous sulfate exhibited the same
or only slightly higher removal than lime alone.
In other tests, lime plus ferric sulfate was evaluated
for possible enhanced removal of arsenic and chromium. Lime
plus sodium sulfide was also analyzed for enhanced cadmium and
mercury removal. In only one case, for chromium at Plant 1226,
was an increased reduction in concentration achieved over lime
precipitation alone. The inlet concentrations at this plant
were very low, however, 4 ppb and 6 ppb in the cooling tower
blowdown and ash pond effluent, respectively. These results
are presented in more detail in Section 6.
3.2.4 Results of Treatment by Reverse Osmosis
The results of the chemical analyses for removal of
organic compounds by reverse osmosis are presented in Table 3-4.
The data in the table demonstrate the effectiveness of reverse
osmosis in removing most of the eight compounds presented. Re-
moval of toluene was the only exception. In general, the inlet
concentrations were too low to produce definitive results.
The results of the analysis for removal of inorganics
by reverse osmosis are summarized in Table 3-5. Concentrations
of most of the compounds were significantly reduced by this
15
-------
TABLE 3-4. SUMMARY OF REVERSE OSMOSIS PERFORMANCE
FOR ORGANIC COMPOUNDS3
Inlet Outlet Observed removal
concentration concentration efficiency
Compound (ppb) (ppb) (*>
Benzene
Plant 5604 (CTB)c 58
Plant 5409 (APE) <1 <1 —
Bromodichloromethane
Plant 1226 (CTB) 8.2 >88
Plant 5409 (CTB) 2.6 >62
Dibromochloromechane
Plant 1226 (CTB) 58.5 <1 >98
Plant 1226 (APE) <1 <1 —
Plant 5409 (CTB) <1 —
3 IT onto £ o ES
Plant 1226 (CTB) 154 <1 >99
Plant 1226 (APE) <1 <1 _
Trlchloroethylene
Plant 5409 (CTB) <4 <4 _
a A. blank, in the column signifies the compound was not identified as being
present.
°< - Designates concentration below detection limit
CCTB - Cooling tower blowdown
dAPE Ash pond effluent
16
-------
TABLE 3-5. SUMMARY OF REVERSE OSMOSIS PERFORMANCE
FOR INORGANIC COMPOUNDS
Compound
Arsenic
Plant 5604 (CTB)*
Plant 5604 (APE)b
Plant 1226 (CTB)
Plant 1226 (APE)
Plant 5409 (CTB)
Plant 5409 (APE)
Copper
Plant 5604 (CTB)
Plant 5604 (APE)
Plant 1226 (CTB)
Plant 1226 (APS)
Plant 5409 (CTB)
Plant 5409 (APE)
Lead
Plant 5604 (CTB)
Plant 560'- (APE)
Plant 1226 (CTB)
Plant 1226 (APE)
Plant 5409 (CTB)
Plant 5409 (APE)
Selenium
Plant 5604 (CTB)
Plant 5604 (APE)
Plant 1226 (CTB)
Plant 1226 (APE)
Plant 5409 (CTB)
Plant 5409 (APE)
Inlet
concentration
(ppb)
7
75
>39
—
>99
32
89
79
29
92
65
—
—
—
>25
>96
—
—
>33
—
>75
—
85
?CTB - Cooling Cower blowdown
APE - Ash pond effluent
< - Designates concentration below detection limit
17
-------
technology. A comparison of this table with Table 3-3 indicates
that reverse osmosis was more effective than chemical precipita-
tion for the removal of selenium. It was also as effective for
removing the other compounds.
3.2.5 Results of Vapor Compression Distillation Performance
The vapor compression distillation (VCD) unit sampled
at Plant 3009 was analyzed for the removal of both organic and
inorganic compounds. The concentrations of the few organic
compounds observed were very low and no definitive results were
obtained. The analysis of inorganics was definitive. High
concentrations of copper (2,700 ppb), vanadium (1,000 ppb) and
zinc (910 ppb) were observed in the inlet to the unit. Most
were removed from the wastewater and concentrated in the brine
reject stream. The only significant concentration of a compound
in the product stream was vanadium (590 ppb) .
18
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SECTION 4
PLANT CHARACTERIZATION AND SAMPLING LOCATIONS
Background information characterizing the plants
studied is presented in this chapter. The characterization
includes the size of the plant, the type of coal burned, flue
gas clean-up methods, and detailed descriptions of the water
supply and wastewater streams which were sampled. The sampling
points used in each plant are also identified.
The coal-fired power plants studied were all baseload
facilities. All employed cooling towers for heat rejection and
ash ponds for disposal of fly ash. A summary of the data per-
tinent to the study for each plant is presented in Table 4-1.
4.1 PLANT WATER/WASTEWATER CHARACTERIZATIONS AND
LOCATION OF SAMPLE POINTS
The water and wastewater streams studied are described
in this section. Particular emphasis was placed on identifying
all wastewater streams entering the ash pond systems. For Plants
5604, 1226, and 5409, the cooling water systems and ash ponding
systems are described. For Plant 3009 the sampling concerned
only the VCD units and the wastewater stream going into the unit.
4.1.1 Plant 5604
Water/Wastewater Characterization--
The plant water/wastewater system can be divided into
three major parts:
19
-------
TABLE 4-1. SUMMARY OF PLANT CHARACTERISTICS
Plant
Total generating
capacity
Fuel
Flue gas
cleanup
5604
4 units, 750 KW
1226 7 units, 1229 MW
Sub-bituminous coal
Ash, 12%
Sulfur, 0.5%
Natural gas units
1, 2 & 3
Fuel oil: units 4 & 5
Electrostatic
precipitators,
Wet venturi
unit 4
Electrostatic
precipitators
5409
3009
Ash content of fuel
oil, 0.06%
Coal: units 6 & 7
Illinois bituminous coal
Ash, 11%
3 units, 2900 MW Coal (numerous suppliers) Electrostatic
2 units, 716 MW
Ash, 15%
Sulfur, 1.0%
Sub-bituminous coal
Ash, 6.1-12.6%
Sulfur, 0.4-1.0%
precipitators
Combined scrubbers
(fly ash and
removal)
Mechanical draft cooling
tower for unit 4
Once-through mechanical
draft cooling - winter
months, units 1, 2 & 3
Mechanical draft cooling
tower for summer months
Mechanical draft cooling
tower for unit 6
Mechanical draft cooling
tower for unit 6
Natural draft cooling
towers - one for each
unit
Mechanical draft cooling
-------
1. A once-through cooling water system
which provides the cooling for three
of the plant's four generating units.
A cooling tower is used during the
summer months.
2. A recirculating cooling water system
which uses a cooling tower to provide
the cooling duty.
3. Four ash ponds make up the ash ponding
system. The system is composed of
two separate systems. Two of the ash
ponds serve Units 1, 2, and 3, and two
ash ponds plus a clear pond serve
Unit 4.
Makeup water for both cooling systems comes from
the nearby river. The water is chlorinated prior to in-plant
use. The cooling towers are usually operated between 3 and
4 cycles of concentration. Water from the clear pond is used
to sluice bottom ash from the four boilers. The ash sluice
water is returned to the ash ponds. Makeup water to the ven-
turi scrubbers is also taken from the clear pond and the blow-
down from the scrubber water system is sent to the ash ponds.
Boiler blowdown, roof and yard drainage, coal pile
runoff, and demineralizer regeneration wastes are all dis-
posed in the ash ponds for Units 1, 2, and 3. Metal cleaning
wastes are either hauled off-site or disposed in the ash dis-
posal area. Figure 4-1 is a general flow diagram of the plant
water/wastewater systems for Units 1, 2, and 3. Figure 4-2
covers all water systems for Unit 4.
21
-------
CHLORINE
N>
RIVER
CONDENSERS
UNITS BOTTOM ASH SLUICE
NOTE: COOLING TOWER USED
DURING SUMMER MONTHS
\
COOLING TOWER
ROOF, YARD AND PLANT DRAINS
BOILER SLOWDOWN
WATER TREATMENT PLANT WASTES
COAL PILE RUNOFF
SETTLING
PONDS(2)
V SAMPLE POINT
Figure 4-1. General water flow diagram of water/wastewater system
for Units 1, 2, and 3 of Plant 5604.
-------
iCItUUUEH lil.ILD LIQUOK
UNIT DOTTOM ASH
CO
CONDENSED
IUVI l( WAII.lt
MAKEUP
SAMI'Ll I'OINIS
Figure 4-2.
General water flow diagram of water/
wastewater system for Unit 4 of
Plant 5604.
-------
Various chemicals are added to the plant water/waste-
water system. Chlorine is added to the plant intake water.
Chemicals added to the boiler water include sodium hydroxide,
hydrazine, and phosphate. Chlorine, sulfuric acid, a commercial
biocide, and lime are added to the recirculating cooling system
water. Chlorine is added to the once-through cooling system
when in use.
Sampling Points--
Water samples of the plant inlet water, cooling tower
blowdown, and ash pond overflow were analyzed to identify the
priority pollutants present in each stream. The treatment tech-
nologies were tested at the same time the raw samples were taken
to eliminate variations in composition with respect to time.
The sampling points are shown in Figures 4-1 and 4-2 and are
listed below:
Plant Inlet Water - inside the plant
at a point just upstream of the plant's
condensers (see Figure 4-1).
Cooling Tower Blowdown - upstream of
chlorine addition but downstream from
acid addition at a point between the
cooling towers and the recirculation
pumps. This cooling tower services
Unit 4 only.
Ash Pond Effluent - at dewatering pumps
from ash pond just before clear pond.
24
-------
4.1.2 Plant 1226
Plant Water/Wastewater Characterization—
The plant water/wastewater system is made up of
three major components:
1. A once-through cooling water system
with a cooling tower downstream for
temperature control before discharge.
This system provides the cooling
for Units 1 through 5.
2. A recirculating cooling water system
with cooling towers providing the
cooling for Units 6 and 7.
3. An ash sluicing system which includes
one ash pond for allowing ash and other
settleable matter to be removed from
the ash sluice water from Units 4, 5,
6, and 7 as well as from other plant
effluent streams.
Makeup water for both cooling systems comes from
a local river. Ash sluice water is taken from the recircula-
ting cooling water system and piped to the ash pond for dis-
posal. A blowdown stream from the recirculating cooling sys-
tem is piped directly to the ash pond.
Those waste streams sent to the ash pond include
demineralizer regeneration wastes, floor drains, coal pile
runoff, and laboratory drains. Metal cleaning wastes
25
-------
containing copper are discharged to a lined pond where they
are aerated and neutralized with lime. A polymer is added
to enhance settling of the precipitated copper. Figure 4-3
is a general flow diagram of the plant water/wastewater system.
Daily additions of chlorine are made to the plant
recirculating cooling water system for the control of bio-
logical growth within the system. The chlorine is added
during two 30-minute periods, one in the morning and one in
the afternoon. The quantity of chlorine added during each
period is 156 pounds.
Sampling Points--
Water samples of the plant inlet water, cooling tower
blowdown, and ash pond overflow were analyzed to identify the
priority pollutants present in each stream. The treatment tech-
nologies were tested at the same time as the raw samples were
taken, eliminating time variable problems. These sampling
points are shown in Figure 4-3 and are listed below:
Plant Inlet Water - at the inlet pipe
discharge into the cooling tower basin.
Cooling Tower Blowdown - upstream of
the cooling water recirculating pumps
and immediately before the chlorine
and sulfuric acid addition points.
Ash Pond Overflow - at the pond outfall.
26
-------
to
RIVER
COAL PILE RUNOFF V ^-
ROOF ft YARD DRAINAGE t >—
ASM POND
ASH SLUICE
COOLING TOWER BASIN POND
COOLING TOWER
BLOWDOWN
PLANT INTAKE
L- Sample point
ASH POND
EFFLUENT
DISCHARGE
CHANNEL
METAL CLEANING
, WASTE
LINED
POND
Figure 4-3. General flow diagram of plant water/wastewater system
for Plant 1226.
-------
4.1.3 Plant 5409
Plant Water/Wastewater Characterization "
The plant water and wastewater system can be
divided into four major components:
1. A water system that provides the
water required for Units 1 and 2.
2. A water system that provides the
water required for Unit 3.
3. A dual pond arrangement for re-
ceiving the primary wastes from
all three units.
4. A fly ash pond for receiving fly
ash sluice water from all three
units.
At present, the plant has river makeup water intakes at each
of the three cooling towers and only one plant discharge
which comes from the fly ash pond overflow. Figure 4-4 is a
schematic of the plant water/wastewater system.
The subsystem for Units 1 and 2 uses pyrite wash
water and a portion of the cooling tower blowdown for bottom
ash sluicing. On rare occasions, river water may also be
used for bottom ash sluicing. The cooling towers for Units 1
and 2 are hyperbolic natural draft structures having a com-
bination asbestos/cement fill. Average circulation, blowdown,
and makeup rates are given in Table 4-2. All primary wastewater
28
-------
ve
fit ASH POHU
OISCMAIIOE
TO CREEK
me«e MOO
A OAMI'lt 1'HIHIO
fl» A8II
(.041 HOD
"'.'"
MOO MAX
Figure 4-4. Plant 5409 water/wastewater system.
-------
streams, such as bottom ash sluice, pyrite water, cooling
tower blowdown, sumps, and area runoff, are sent to the
primary settling pond. Pyrite water is taken from the
secondary clear pond.
TABLE 4-2. COOLING TOWER OPERATING DATA FOR PLANT 5409
Circulation rate (gpm)
Blowdown rate (gpm)
Makeup rate (gpm)
Average number of cycles
pH
Unit 1
248,000
770
4,600
7
7.4-7.6
Unit 2
248,000
770
4,600
7
7.4-7.6
Unit 3
600,000
1,300
8,000
7
7.4-7.6
The subsystem for Unit 3 has no internal recycle
streams. All bottom ash sluice water is taken from the
secondary clear pond and all primary wastewater streams are
sent directly to the primary settling pond. The cooling
tower for Unit 3 is similar to those for Units 1 and 2, but
larger. Average circulation, blowdown, and makeup rates are
given in Table 4-2.
Flue gas cleaning is accomplished with electro-
static precipitators (ESP). Fly ash from the ESP units is
sluiced to the fly ash pond.
Other wastestreams, such as coal pile runoff and
metal cleaning wastes, are also sent to the primary settling
pond. Metal cleaning wastes are generated from boiler tube
cleanings, which are scheduled for each unit about every two
years.
30
-------
Water from the secondary clear pond is used for
sluicing fly ash from the electrostatic precipitators to a
large fly ash holding pond. The overflow from the fly ash pond
is discharged to a nearby creek. At present, this outlet is the
only discharge from the entire plant water and wastewater sys-
tem.
The only chemical additions to the plant water system
are chlorine and sulfuric acid. Both chemicals are added to the
cooling water system at the inlet to the recirculating pumps
which are located between the cooling tower basin and the con-
densers. Chlorination for algae control is done once a day,
Monday through Saturday, for a one-hour period. The injection
rates for chlorine are usually 250 Ib/hr for Units 1 and 2 and
333 Ib/hr for Unit 3. Sulfuric acid (9370) is continuously
added to control the pH of the cooling water. The pH is main-
tained between 7.4 and 7.6.
The boilers at Plant 5409 are designed to operate
at supercritical temperatures with ultra-pure feedwater. No
blowdown of boiler water is required. The ultra-pure feed-
water is obtained from a seven-step water treatment process
utilizing demineralizers. The only waste stream from the de-
mineralizers comes from regeneration of the cation and anion
resins which is an intermittent process.
Sampling Points--
Sampling was done at three separate points within
Plant 5409. These points are shown on Figure 4-4 and de-
scribed below:
31
-------
Plant Makeup - taken at the pump which
supplies river water to the Unit 2
cooling tower.
Cooling Tower Effluent - taken at the
Unit 2 cooling tower basin immediately
upstream of the recirculating pumps.
Ash Pond Effluent - taken at the pond
outlet to the creek.
4.1.4 Plant 3009
Plant Water/Wastewater Characterization--
The plant water system is designed for zero aqueous
discharge. Water losses occur through cooling tower evaporation
and drift, scrubber evaporation, pond evaporation, solids occlu-
sion, and boiler losses. Plant makeup water is taken from a
nearby river. Figure 4-5 is a schematic of the plant water sys-
tem. All continuous wastewater streams from the plant are piped
to the vapor compression distillation (VCD) units where the prod-
uct water is returned to the plant for reuse and the reject
stream is ponded.
Vapor Compression Distillation--
Two vapor compression distillation units at Plant 3009,
designed by the Research Conservation Corporation, came onstream
in late spring and summer of 1976. A diagram of the VCD unit is
provided in Figure 4-6. The sample points are indicated on this
diagram.
32
-------
licit! MAIla
10
Figure 4-5. Plant 3009 water flow scheme.
-------
BECinCULATION LINE
PRESSURE EQUALIZATION
LINE
A SAMPLE POINT*
PRODUCT
ICONOEH8AIEI
SULFUBIC ACID
INJECTION
Figure 4-6. Vapor compression distillation unit.
-------
Each unit is designed for a raw feed of 175 gpm and a
98.8% product recovery rate. This design produces a brine waste
stream of approximately 2.1 gpm. At the time of the sampling,
the waste stream flow was slightly higher than normal, averaging
2.5 to 3.0 gpm. Plant personnel attributed the higher waste rate
to a higher solids content in the raw feed.
Feed to the VCD unit is supplied by cooling tower
blowdown (CTB) and/or a CTB surge pond (Pond C) as shown on
Figure 4-5. Inlet temperatures vary with the feed source. The
feed is treated with sulfuric acid for pH adjustment and heated
in a product heat exchanger prior to deaeration. No data were
available on the amount of steam loss from the deaerator vent,
but estimated overall steam consumption for each VCD unit is
400 Ib/hr of medium pressure steam.
From the deaerator, the feed undergoes heat exchange
with the product stream before entering the sump of the VCD
unit. The sump temperature is about 209°F. Vapors rising from
the sump pass through a mist eliminator to remove any entrained
brine or other liquid contaminants. The water vapor is then
compressed and fed into the condenser.
Brine is pumped from the sump into the floodbox and
descends through the condenser tubes by gravity flow. Water
vapor, condensing on the outside of the tubes, heats the brine,
which partially evaporates before returning to the sump. The
condensed water is drawn off through a product line and run
through two exchangers in series for feed reheat. Temperature
of the product stream averages 109-194°F. The product water is
either sent to demineralizers for boiler makeup, S02 scrubbers,
or the recycle tank. A constant brine level is maintained in
35
-------
the sump by pumping a small amount of brine from the VCD recycle
line to one of two lined two-acre ponds.
Sampling Points--
Samples were taken at four separate points on VCD Unit
A. These points, shown on Figure 4-6, were:
Raw feed inlet prior to sulfuric acid
inj ection.
Product condensate after the primary heat
exchanger.
Brine waste directly below the sump.
Vent gas from the deaerator.
During the sampling period, all raw feed was supplied from Pond
C and contained no blowdown directly from the cooling towers.
36
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SECTION 5
CHEMICAL ANALYSIS OF UNTREATED WATER SAMPLES
The results of the laboratory analyses of the untreat-
ed water streams are presented in this section. The results are
organized to emphasize both the types of compounds and the con-
centrations encountered at the different plants. For each of
three plants, 5604, 1226, and 5409, the data characterize the
inlet water to the plant, the cooling tower blowdown and the ash
pond effluent. The inlet streams to the plants were analyzed
to provide a comparison of the pollutant concentrations entering
the plants with those in the plant wastewaters. For Plant 3009,
the inlet stream to the vapor compression distillation unit was
characterized for inorganic compounds. As GC-MS confirmations
were not run for the VCD inlet stream, the organic analyses for
the VCD unit are not positive identifications.
5.1 ORGANIC COMPOUNDS
The inlet and wastewater streams were characterized
for priority organic compounds by gas chromatography (GC) analy-
sis and gas chromatography-mass spectrometry (GC-MS) analysis.
The GC-MS was used to positively identify compounds that were
tentatively identified by the GC analysis. The limitations of
the two methods of analysis and the significance of the concen-
trations determined by each are discussed in detail in the
Appendix. For the purposes of data presentation, the results
of the GC analyses are presented in this section. However, as
GC analysis does not positively identify the presence of a
37
-------
compound, it was concluded that the compound was not present
unless confirmed by the GC-MS analysis.
Both the GC and GC-MS results for the analysis of
organic compounds are presented in Tables 5-1 through 5-6 for
plants 5604, 1226, and 5409. The concentrations observed by the
two instruments were usually different, as can be seen in the
tables. The sensitivity to concentrations of a given compound
is different for GC and GC-MS; therefore, variations exist in
concentrations presented in the two tables for a given compound.
The difficulty of resolving the sensitivity of the instruments
at the very low concentrations observed contributed to the
differences in concentration. In many instances a concentration
was measured but was below the defined detection limit. This
meant that the compound was present but at such a low concen-
tration that it could not be quantified. A concentration pre-
ceded by "<" designates the detection limit for a compound which
was identified but was present at a concentration too low to be
quantified. A blank in the tables signifies that a compound
was not identified as being present. The results of the GC
analysis of the inlet stream to the VCD unit at Plant 3009 are
not included as no GC-MS confirmation was performed on this
sample. The sampling at this plant was done only as a means of
evaluating VCD performance.
The results of the analysis for organic priority
pollutants at Plant 5604, presented in Table 5-1, indicate that
the intake stream to the plant was relatively clean. The only
notable concentration was for toluene, which was just below 10
ppb. A comparison of the compounds present in the plant inlet
with those in the cooling tower blowdown stream and the ash
pond effluent indicates that most of the compounds found in the
wastewater streams were present in the inlet. The differences
38
-------
TABLE 5-1. PLANT 56.04: ORGANIC ANALYSES OF RAW WATER SAMPLES
BY GAS CHROMATOGRAPHY (Concentrations in ppb)3
Compound
Chloroform
Benzene
Toluene
Ethylbenzene
Phenol
Dimethyl Phthalate
Diethyl Phthalate
Fluoranthene
3,4 Benzofluoranthene or
11,12 Benzofluoranthene
Di-n-butyl Phthalate
Sample stream
Plant Cooling tower
make-up blowdown
1.2 <1
9.1 23.5
c
No sample 2.4
,* *
* *
2.0
4.0
* *
Ash pond
effluent
-------
TABLE 5-2.
PLANT 5604: ORGANIC ANALYSIS OF RAW WATER SAMPLES
BY-GAS CHROMATOGRAPHY - MASS SPECTROMETRY
(Concentrations in ppb)a
Compound
Chloroform
Bromoform
Trichloroethylene
Tetrachloroethylene
Benzene
Toluene
Ethylbenzene
Di-n-butyl Phthalate
Bis (2-ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Diethyl Phthalate
Plant
make-up
0.3
0.1
16
0.9
0.5
0.5
1.0
1.4
1.0
Sample stream
Cooling tower
blowdown
8.3
0.5
0.7
7.7
50
Ash pond
effluent
0.2
19
0.6
0.8
0.7
1.6
1.0
4.9
aA blank in the table signifies that a compound was not identified as being
present.
40
-------
TABLE 5-3. PLANT 1226: ORGANIC ANALYSES OF RAW WATER SAMPLES
BY GAS"CHROMATOGRAPHY (Concentrations in ppb)a
Compound
Chloroform
Bromodichlorome thane
Dibromochloromethane
Bromoform
Tetrachloroethylene
Benzene
Toluene
Phenol
Dimethvl Phthalatec
Sample stream
Plant Cooling tower
make-up blowdown
-------
TABLE 5-4.
PLANT 1226: ORGANIC ANALYSIS OF RAW WATER SAMPLES
BY GAS CHROMATOGRAPHY - MASS SPECTROMETRY
(Concentrations in ppb)a
Compound
Bromodichlorome thane
Bromoform
Chloroform
Dibromochloromethane
1,1, 1-Trichlo roe thane
Bis(2-ethylhexyl)
phthalate
Di-n-butyl Phthalate
Sample stream
Plant Cooling tower
make-up b lowdown
13
54
3.3
53
0.8
5.2 1.2
15 4.8
Ash pond
effluent
2.2
0.7
0.8
1.3
9.4
aA blank in the table signifies that a compound was not identified as being
present.
42
-------
TABLE 5-5.
PLANT 5409: .ORGANIC ANALYSES OF RAW WATER SAMPLES
BY GAS CHROMATOGRAPHY (Concentrations in ppb)a
Sample stream
Compound
Plant
make-up
Cooling tower
blowdown
Ash pond
effluent
1,1 Dichloroethane
-------
TABLE 5-5
(Cont.)
Compound
Plant
make-up
Sample stream
Cooling tower
blowdown
Ash pond
effluent
Hexachlorocyclopentadiene
4 Bromophenyl Ether £r a BHC
Y BHC or 5 BHC (Benzenehexa-
chloride)
Aldrin
Heptachlor Epoxide
a Endosulfan
Dieldrin or_ DDE
Endrin
DDT
A blank in the table signifies that a compound was not identified as being
present.
< - Designates concentration below detection limit.
Phthalates cannot be quantified due to sample contamination.
Merged peaks.
44
-------
TABLE 5-6.
PLANT 5409 : ORGANIC ANALYSIS OF RAW WATER SAMPLES
BY GAS CHROMATOGRAPHY - MASS SPECTROMETRY
(Concentrations in ppb)a
Compound
Bromodlchlorome thane
Carbon Tetrachloride
Chloroform
Dibromochloromethane
1,1,2, 2-Tetrachloroe thane
Trichloroethylene
Benzene
Ethylbenzene
Toluene
Phenol
1,3 and 1,4-Dichlorobenzene
1, 2-Dichloro benzene
Hexachlo robenzene
Bis(2-ethylyhexyl) Phthalate
Di-n-butyl Phthalate
Plant
make-up
1.1
1.5
0.5,
0.6
2.3
1.6
0.5
0.9
8.5
0.6
14
2.2
Sample stream
Cooling tower
' blowdown
3.1
11
0.3
0.5
0.6
0.6
0.6
0.9
5.7
3.3
Ash pond
effluent
0.3
0.6
0.8
0.4
7.1
6.1
A blank in the table signifies that a compound was not identified as being
present.
45
-------
in observed concentration levels can generally be attributed to
the cycles of concentration which were 4 for the cooling tower
and 2.6 for the ash pond.
Several phthalates were observed; however, these are
believed to be the result of sample contamination occurring in a
filtering step during sample preparation. No significance is
attached to the indicated presence of these compounds due to the
contamination.
The GC-MS analysis detected several compounds that
were not observed by the GC analysis. These included chloro-
form, carbon tetrachloride, bromochloromethane and bromoform in
the plant inlet stream. The GC-MS measured concentration levels
were low, less than 3 ppb in all cases. Significant concentra-
tions of trichloroethylene were observed in both the cooling
tower blowdown and the ash pond effluent by the GC-MS. It is
not known why these compounds were not observed by the GC.
The results of the analysis for organics at Plant 1226
are presented in Tables 5-3 and 5-4. Several volatile organics
were observed in the cooling tower blowdown at this plant. The
river intake was clean, however. It should be noted that the
water intake to this plant is in a tidal estuary and the quality
of the intake water varies both diurnally and seasonally. As a
result, the quality of the water in the plant at any given time
may be appreciably different from the water coming into the
plant. The concentration levels observed for dibromochloro-
methane and bromoform were high, 59 ppb and 154 ppb, respectively.
Trace quantities of these were also observed in the ash pond
water. Phthalates were also measured; however, these were
probably filter contaminants as discussed earlier.
46
-------
The results of the analyses for organics at Plant 5409
are presented in Tables 5-5 and 5-6. There were 15 compounds
observed in the river intake to this plant. Only eight were
confirmed by GC-MS analysis. Of these only benzene, phenol,
1,3 dichlorobenzene, 1,4 dichlorobenzene and 1,2 dichloroben.zene
were observed at concentrations greater than 2 ppb. Most of
the compounds observed in the cooling water and ash pond water
were measured at or near the same concentration levels as in
the plant inlet water. Several compounds were seen in the cool-
ing water and ash pond water that were not seen in the plant
intake.
5.2 INORGANIC COMPOUNDS
Each sample of water was analyzed for 15 inorganic
priority pollutants. In addition to these compounds, chlorides,
pH, suspended solids and total organic carbon were identified
for each sample. Chlorides were included as a means of estima-
ting the concentration factor. This was done by comparing the
chlorides in the ash pond or cooling basin to the level in the
intake water. Total suspended solids, pH, and total organic
carbon were included as standard parameters for characterizing
water and wastewater streams.
The untreated water streams for plant 5604, 1226, and
5409 are presented in Tables 5-7 through 5-9. The inorganic
analysis of the feed stream to the VCD unit at Plant 3009 is
presented in Table 5-10.
The results of the analysis for inorganic compounds at
Plant 5604, Table 5-7, indicate that the most significant con-
centrations encountered were for copper and zinc. In general,
the inlet concentrations for the species presented in the table
47
-------
TABLE 5-7. PLANT 5604: INORGANIC ANALYSIS OF RAW
WATER SAMPLES (Concentrations in ppb
unless otherwise noted)
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Cl~
CN~
PH
Total Suspended Solids
Total Organic Carbon
Plant intake
water
4
-------
TABLE 5-8. PLANT 1226: INORGANIC ANALYSIS OF RAW
WATER SAMPLES (Concentrations in ppb
unless otherwise noted)
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Cl~
CN~
PH
Total Suspended Solids
Total Organic Carbon
Plant intake
water
7
3
<0.5a
2.1
7
12
10
0.4
1.5
<2.0
1.3
<1.0
40
9
360 ppm
7
20 ppm
Cooling tower
blowdown
7
4
<0.5
1.8
5
47
3
0.2
6.0
<2.0
0.7
<1.0
27
26
490 ppm
5
6.8
3 ppm
20 ppm
Ash pond
effluent
7
9
<0.5
2.0
6
14
4
<0.2
5.5
8
0.5
<1.0
78
7
790 ppm
<1
9.1
9 ppm
<20 ppm
*< - Designates concentration is below detection limit.
49
-------
TABLE 5-9.
PLANT 5409: INORGANIC ANALYSIS OF RAW
WATER SAMPLES (Concentrations in ppb
unless otherwise noted)
Arsenic
Antimony
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Cl~
CN~
PH
Total Suspended Solids
Total Organic Carbon
Plant' intake
water
<1.0 a
3
<0.5
1.4
<2.0
27
8
<0.2
1.7
<2.0
1.6
<1.0
13
15
5 ppm
5
20 ppm
Cooling tower
blowdown
35(<1.0)b
<1.0
3.4
0.8
37
3800(620)
130(70)
0.5
4.0
<2.0
14
8
11
290(61)
110 ppm
5
6.8
460 ppm
21 ppm
Ash pond
effluent
74
5
<0.5
<0.5
<2.0
26
<3.0
<0.2
2.5
42
1.0
9
31
11
28 ppm
13
6.7
14 ppm
<20 ppm
< - Designates concentration is below detection limit.
Parenthesis indicates concentration of dissolved fraction.
50
-------
TABLE 5-10. RESULTS OF INORGANIC ANALYSIS FOR
INLET WATER TO VAPOR COMPRESSION
DISTILLATION UNIT, PLANT 3009
(Concentrations in ppb unless
otherwise noted)
Inlet to VCD
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
CN~
TOC (ppm)
7
50
<0.5a
1
5
2,675
7
2
3
<2.0
15
<1.0
1,000
906
24
20
a< - Designates concentration is below detection limit.
51
-------
are low (less than 10 ppb) with the exception of copper and zinc.
The concentrations in the cooling tower blowdown show slight
increases in arsenic and nickel. These increases are just
slightly larger than would be expected from the cycles of con-
centration of the makeup water. The cycles of concentration for
the cooling tower water were 4, while the ash pond showed 2.6
based on the chloride concentration. Vanadium increased slight-
ly but was lower in the cooling tower water and ash pond water
than would be expected from the concentration effect. The con-
centration of zinc showed a fifteen-fold increase over the inlet
while copper decreased by a factor of about one-fourth. The
concentrations of the species in the ash pond effluent were
slightly higher than observed in the cooling tower blowdown.
Beryllium, cadmium, chromium, nickel, selenium, silver, vanadium,
and cyanide in the ash pond effluent increased just slightly
as compared to cooling tower blowdown and plant inlet water.
The copper concentration was considerably lower in the ash pond
effluent than in both the inlet water and the cooling tower
blowdown. The zinc concentration in the ash pond was lower than
that observed in the cooling tower blowdown but higher than the
inlet water.
The intake water to Plant 1226, shown in Table 5-8,
was very clean with only copper and vanadium existing in concen-
trations greater than 10 ppb. Copper and zinc concentrations
increased slightly in the cooling tower water as compared to
that at the plant intake. The increases were higher than would
be expected from the 1.4 cycles of concentration observed at the
time of the sampling. The vanadium concentration in the cooling
water decreased noticeably as compared to the plant intake water.
52
-------
The copper concentration in the ash pond was approxi-
mately the same while the vanadium concentration in the ash pond
was twice as high as the intake. The cycles of concentration
for the ash pond as compared to the plant intake were 2.2.
The results of the analysis for inorganics at Plant
5409, presented in Table 5-9, are somewhat unusual. While the
concentrations in the plant inlet were comparable to the other
two plants, the cooling tower blowdown contained higher concen-
trations of arsenic, copper, lead and zinc. However, when a.
sample of this water was filtered through a 10-micron filter,
well over 75 percent of the material was removed. This was
interpreted to mean that the metals were present as suspended
particulate matter. The removal efficiencies calculated in
Section 6.0 were based on the dissolved fraction in the untreat-
ed cooling tower water. The concentration of 37 ppb of chromium
in the cooling tower blowdown is higher than the other plants.
At the time of the sampling, the concentration factor for the
cooling water over the intake water was 7.3.
Arsenic, selenium and vanadium were present in signifi-
cant concentrations in the ash pond effluent. The arsenic con-
centration of 74 ppb was present as dissolved matter and could
have entered the system as a component of the fly ash. The
selenium concentration of 42 ppb was also significant as its
concentration in the plant inlet water and the cooling tower
blowdown was below the detection limit of the analytical proce-
dure. The concentration of vanadium in the ash pond, 31 ppb,
was approximately as expected based on the inlet concentration
of 13 ppb and 2 cycles of concentration.
The data presented in Table 5-10 characterize the feed-
water stream to the vapor compression distillation unit at
53
-------
Plant 3009. This stream contains wastewater from all sections
of the plant. Of particular note are the observed concentrations
of copper, vanadium, and zinc, which were the highest observed
in the study (for an untreated wastewater stream). The arsenic
concentration, 50 ppb, was also noteworthy. As this plant was
included only for the purpose of evaluating VCD performance, no
plant intake samples were analyzed for comparison purposes.
54
-------
SECTION 6
CONTROL EVALUATION
This section presents the data resulting from the
field evaluation of each of the four treatment technologies.
These data are organized according to organic and inorganic
analysis for the four field test sites. Each analysis itemizes
the compounds identified as being present in the cooling tower
blowdown or ash pond effluent before and after treatment by the
.respective control technologies. The types of analyses presented
for each control technology are:
Activated carbon - organics only
Chemical precipitation - inorganics only
Reverse osmosis - organics and inorganics
Vapor compression distillation organics and
inorganics
In addition to quantifying organic and inorganic com-
pounds, each control technology was evaluated for its efficiency
in removing these compounds. The removal efficiencies were cal-
culated using the following equation:
C- - C
E = ^ r ° * 100
Li
where E = observed removal efficiency (%)
C. = inlet concentration
C = outlet concentration
o
55
-------
At each plant, the inlet concentration of a particular wastewater
stream was characterized for all control technologies by one
grab sample. For example, one sample of untreated ash pond water
was analyzed to determine the inlet conditions for the activated
carbon columns, the reverse osmosis unit, and the chemical pre-
cipitation tests.
In many cases, circumstances did not allow the cal-
culation of a removal efficiency. Such cases occurred when
the inlet concentration was at or below the detection limit for
the compound or when the observed outlet concentration was
greater than the inlet concentration. In all cases, the results
of the analyses for compounds in both the inlet and outlet are
presented whether or not a removal efficiency is calculated and,
in the case of organic analysis, whether or not the compound
was confirmed by GC-MS.
A more detailed description of the sampling techniques,
field testing procedures, and laboratory analysis procedures
and accuracies is presented in the Appendix.
6.1 ACTIVATED CARBON
The field testing of activated carbon to evaluate
removal of trace organics was accomplished using 0.5-inch ID
glass columns packed with 60 inches of Calgon Filtrasorb 400
granular activated carbon. By using a constant displacement
pump, a continuous feed of 10 ml/min was maintained during the
performance testing and resulted in a liquid residence time of
about 14 minutes. The activated carbon was washed with nitric
acid prior to being packed in the columns. This procedure
lessened the chance of sample contamination by ash material in
the carbon.
56
-------
Tables 6-1 through 6-3 present the results of the chem-
ical analyses for organic compounds in the outflow from the car-
bon columns at each of the plants tested. Each table contains
both the cooling tower blowdown and ash pond effluent results
for the plants tested.
The results for Plant 5604 are presented in Table 6-1.
Only one compound was observed in a concentration greater than
10 ppb. Toluene was observed at 23.5 ppb in the cooling tower
blowdown. Activated carbon reduced the concentration to 3.9 ppb,
a reduction of 83 percent. The toluene concentration measured
in the exit from the column was higher than the inlet for the
ash pond effluent sample. In general, the inlet concentrations
of the few compounds present were so low that little or no
removal was observed.
The results for Plant 1226 are summarized in Table
6-2. Several compounds were observed in the inlet sample for
cooling tower blowdown but not observed as being present in the
effluent. These were bromodichloromethane, dibromochloromethane,
bromoform, and benzene. It is not known whether these compounds
were effectively eliminated or whether the wastewater sample
used for evaluation was of different composition than the sample
representing inlet conditions. As shock chlorination was being
performed at the time of sampling, it is possible that the sample
analyzed to represent inlet conditions was of different quality
than the inlet sample to the carbon column.
The results for Plant 5409 are presented in Table 6-3.
Although 13 compounds were identified as being present in the
cooling tower water, only six were measured above the detection
limit. In addition, only five compounds were confirmed by GC-MS
analysis. Of these five compounds, only one (benzene) was
57
-------
TABLE 6-1.
PLANT 5604: REMOVAL OF ORGANIC COMPOUNDS BY ACTIVATED CARBON
(Concentrations in ppb)a
Ln
00
Cooling tower
blowdown
Observed removal
Compounds Inlet
Chloroform
Benzene 50
3.5/ 7.0
-------
TABLE 6-2. PLANT 1226: REMOVAL OF ORGANIC COMPOUNDS BY ACTIVATED CARBON
(Concentrations in ppb)a
Compounds
Cooling tower blovdown
Observed removal
Inlet Outlet efficiency.%
Ash pond effluent
Observed removal
Inlet Outlet efficiency,% -
Ul
MO
1,2,4 Trichlorobenzene or
hexachlorobutadiene
Y BHC 0£ 88
>98
>99
>74
N/A
<2
2.0
2.3
N/A
1.0
*
A blank in the table signifies that a compound was not identified as being present,
/ - Designates concentration below detection limit.
*!< - Indicates that presence of this compound was confirmed by GC-MS analysis.
Questionable identification and concentration.
JTN/A - Not Analyzed.
Phthalates cannot be quantified due to sample contamination.
-------
TABLE 6-3.
PLANT 5409 REMOVAL OF ORGANIC COMPOUNDS BY ACTIVATED CARBON
(Concentrations in ppb) a
Compounds
Cooling tower blowdown
Observed removal
Inlet Outlet efficiency,%
Ash pond effluent
Observed removal
Inlet Outlet efficiency,%
Dimethyl phthalate
Diethyl phthalate
Fluoranthene
Butyl benzyl phthalate
Bis (2 ethylhexyl)
phthalate or 1.2
benzanthracene or
chrysene
Di-n-butyl phthalate
Pyrene
1,3 Dichlorobenzene
Bis (2-chloro-isopropyl)
ether or bis (2-chloro-
ethyl) ether
Hexachlorocyclopentadiene <1
4 Bromophenyl ether or
a BHC <1
Y BHC (^r 6 BHC (benzene-
hexachloride)
Aldrin
Heptachlor epoxide <1
a Endosulfan <1
Dieldrin or DDE <1
Endrin
*
*
1.0
A
A
A
1.0
A
A
1
1.8
2.3
A
A
1.6
1.2
<1
<1
-------
TABLE 6-3.
(Cont.)
Cooling tower blowdown Ash pond effluent •
Observed removal Observed removal
Compounds Inlet Outlet efficiency,% Inlet Outlet efficiency,%
DDT <1
1,1 Dichloroethane <1 — <1
Chloroform 2.4/ >58 <1 <1
1,2 Dichloroethane <1 —
Bromodichloromethane 2.6/ >62
1,2 Dichloropropane
Trichloroethylene
Dibromochloromethane 33 l.O/ <1
Toluene <1 —
-------
identified in the carbon column effluent and it was reduced
below the detection limit. In the ash pond effluent nine com-
pounds were identified as being present, but only three were
confirmed by. GC-MS analysis. Again, these compounds were either
reduced below the detection limit or completely eliminated by
the activated carbon. In general, the very low inlet concen-
trations for most compounds in both wastewater streams make it
difficult to evaluate the removal efficiencies of this technology.
6.2 CHEMICAL PRECIPITATION
Four chemicals were used in batch precipitation tests
performed with sample water from both of the waste streams tested.
Lime was used as the primary precipitating agent, with ferrous
sulfate tested for possible enhanced removal from coprecipitation
mechanisms. In addition, ferric sulfate and sodium sulfide were
tested to examine their effect upon specific metals. Ferric sul-
fate was examined for arsenic and chromium removal. Sodium sul-
fide was examined for cadmium and mercury removal.
6.2.1 Lime Precipitation
Tables 6-4 through 6-6 present the results of the ana-
lyses for inorganic compounds for the treatment of cooling tower
blowdown and ash pond effluent by lime precipitation. The tables
also provide a percent removal for compounds where appropriate.
The results reported in Table 6-4 for Plant 5604 indi
cate chemical precipitation with lime was effective in decreasing
the concentrations of arsenic, copper, and zinc. These metals
were present in concentrations significantly higher than the
detection limit. The results for nickel were inconclusive.
The nickel concentration in the effluent of the cooling tower
62
-------
TABLE 6-4.
U>
PLANT 5604: INORGANIC REMOVAL EFFICIENCIES FOR LIME PRECIPITATION
(Lime, pH = 11.5) (Concentrations in ppb unless otherwise noted)
Cooling tower blowdown
Arsenic
Antimony
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Total Organic
Inlet
7
5
<0.5
<0.5
<2
180
<3
<0.2
6
<2
3
<1
24
780
Carbonb <20
Observed removal
Outlet efficiency,%
1 >86
3 40
<0.5
<0.5
<2
48 73
<3
<0.2
12
<2
4
<1
77
140 82
Inlet
80
>50
>50
71
—
—
>95
0
9
—
37
90
< - Designates concentration below detection limit.
3 Values are in ppm.
-------
TABLE 6-5.
PLANT 1226: INORGANIC REMOVAL EFFICIENCIES FOR LIME PRECIPITATION
(Lime, pH = 11.5) (Concentrations in ppb unless otherwise noted)
Cooling tower blowdown
Arsenic
Antimony
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Total Organic
Inlet
4
7
<0.5
1.8
5
47
3
0.2
6.0
<2
0.7
<1
27
26
Carbonb<20
Observed removal
Outlet efficiency,% Inlet
3
4
0.9
3.0
9
18
5
0.7
2.9
<2
0.9
<1
6
2
<20
25
43
—
—
—
62
—
—
52
—
—
—
78
92
9
7
<0.5
2.0
6
14
4
<0.2
5.5
8
0.5
<1 '
78
7
<20
Ash pond effluent
Observed removal
Outlet efficiency,%
89
—
—
—
—
29
>25
—
—
0
20
—
0
>71
a< _ Designates concentration below detection limit.
Values are in ppm.
-------
TABLE 6-6.
Ln
PLANT 5409: INORGANIC REMOVAL EFFICIENCIES FOR LIME PRECIPITATION
(Lime, pH = 11.5) (Concentrations in ppb unless otherwise noted)
Cooling tower
Arsenic
Antimony
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Total Organic Carbon
Inlet
<1
<1
3.4
0.8
37
620
70
0.5
4
<2
14
8
11
61
21
blowdown
Observed removal
Outlet efficiency,%
3
4
0.8
<0.5
9
70
<3
0.3
2.3
2
7.8
<1
6
3
<20
—
76
>38
76
89
>96
40
43
—
44
>88
45
95
>5
Ash pond effluent
Inlet
74
5
<0.5
<0.5
<2
26
<3
<0.2
2.5
42
1
9
31
11
<20
Observed removal
Outlet efficiency,!?
<1
4
<0.5
<0.5
<2
12
<3
<0.2
2.2
52
1.1
8
19
<2
<20
>99
20
—
—
—
54
—
—
12
—
—
11
39
>82
< - Designates concentration below detection limit.
Values are in ppm.
-------
blowdown was greater than the inlet value. However, 95 percent
of the nickel was removed from the ash pond. For vanadium the
outlet concentration from the cooling tower blowdown sample was
higher than the inlet value, while 37 percent removal was
observed for the ash pond sample. Lime precipitation also
demonstrated some removal of beryllium, cadmium and chromium in
the ash pond sample. The other species were at or below the
detection limits.
The results of the analyses of the water samples
treated by lime only for Plant 1226 are presented in Table 6-5.
In general, the inlet concentrations for both cooling tower blow-
down and ash pond effluent are very low. However, the data show
that lime precipitation was effective in reducing the concentra-
tions of copper, nickel, vanadium, and zinc in the cooling tower
blowdown. Interestingly, lime precipitation had no effect on
the vanadium concentration in the ash pond effluent. The data
indicate good arsenic removal from the ash pond effluent, but
are too limited to judge the effectiveness of lime precipitation
for removing the other metals.
Table 6-6 presents the results of the inorganic analy-
ses for the treatment of cooling tower blowdown and ash pond
effluent by lime precipitation for Plant 5409. In general, both
inlet streams were fairly clean. Significant concentrations
were observed for chromium, copper, lead and zinc in the cooling
tower blowdown, while arsenic, selenium and vanadium were the
more significant compounds in the ash pond effluent. The data
indicate that lime precipitation was effective in removing
arsenic, chromium, copper, lead and zinc. Some removal of
beryllium and mercury was observed, but the inlet concentrations
were too low to make any firm judgments. In some cases, the
outlet concentration for a metal exceeded the inlet concentration.
66
-------
This discrepancy occurred for selenium in the analysis for both
the cooling tower blowdown and ash pond effluent. The concen-
tration differences are relatively small and may be attributed
to the measurement limitations of the detection equipment.
6.2.2 Lime Plus Ferrous Sulfate Precipitation
Tables 6-7 through 6-9 present the results of lime
plus ferrous sulfate precipitation tests for the removal of
inorganic compounds from the cooling tower blowdown and ash
pond effluent of the three plan/ts tested. Ferrous sulfate was
added to evaluate the influence of coprecipitation mechanisms
on the removal effectiveness.
A comparison of Tables 6-4 and 6-7 (Plant 5604) shows
that, in most cases, the combination of lime and ferrous sulfate
had equivalent or higher observed removal efficiencies than lime
alone. For instance, the observed removal of copper and zinc
from a sample of cooling tower blowdown was definitely increased
from 73 percent to 86 percent for copper and from 82 percent to
95 percent for zinc. In general, the removal efficiencies were
higher, but not dramatically so. One notable exception to this
generality is antimony, for both cooling tower blowdown and ash
pond effluent. The evidence for increased antimony removal
through lime plus ferrous sulfate precipitation from evaluation
of the data is not conclusive.
A comparison of Tables 6-5 and 6-8 (Plant 1226) shows
that little or no improvement in removal efficiency (lime plus
ferrous sulfate over lime alone) can be concluded from the data.
The removal of copper did increase from 62 percent to 91 percent
for cooling tower blowdown and from 29 percent to 50 percent for
the ash pond effluent. However, nickel, vanadium, arsenic and
67
-------
TABLE 6-7.
oo
PLANT 5604: INORGANIC REMOVAL EFFICIENCIES FOR LIME
PLUS FERROUS SULFATE PRECIPITATION
(Concentrations in ppb unless otherwise noted)
Cooling tower
Arsenic
Antimony
Jlery Ilium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Total Organic
Inlet
7
5
<0.5
<0.5
<2
180
<3
<0.2
6
<2
3
<1
24
,780
Carbon b<20
blowdown
Ash pond effluent
Observed removal
Outlet efficiency.% Inlet
86
0
—
—
—
86
—
—
50
—
—
__
—
95
<;L
6
2.5
1
4
80
<3
<0.2
9.5
3
5.5
<1
27
300
<20
Observed removal
Outlet efficiency,%
<;L
30
<0.5
<0.5
<2
23
<3
<0.2
<0.5
3
5
<1
15
25
—
>80
>50
>50
71
— _
>95
0
9
44
92
a< - Designates concentration below detection limit.
^Values are in ppm.
-------
TABLE 6-8.
CTi
VO
PLANT 1226: INORGANIC REMOVAL EFFICIENCIES FOR LIME
PLUS FERROUS SULFATE PRECIPITATION
(Concentrations in ppb unless otherwise noted)
Cooling tower blowdown
Arsenic
Antimony
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Total .Organic
Inlet
4
7
<0.5a
1.8
5
47
3
0.2
6.0
<2
0.7
<1
27
26
Carbonb <20
Observed removal
Outlet efficiency,% Inlet
3
9
<0.5
1.6
3
<4
<3
<0.2
6.0
<2
0.4
<1
12
2
<20
25
—
—
11
40
>91
>0
>0
0
—
43
56
92
9
7
<0.5
2.0
6
14
4
<0.2
5.5
8
0.5
<1
78
7
<20
Ash pond effluent
Observed removal
Outlet efficiency, %
3
9
<0.5
3.2
4
7
<3
0.6
9.0
7
0.4
<1
82
6
<20
67
—
—
—
33
50
>25
—
—
13
20
—
—
14
< - Designates concentration below detection limit.
Values are in ppm.
-------
TABLE 6-9.
PLANT 5409: INORGANIC REMOVAL EFFICIENCIES FOR LIME
PLUS FERROUS SULFATE PRECIPITATION
(Concentrations in ppb unless otherwise noted)
Cooling tower blowdown
Arsenic
Antimony
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Total Organic
Inlet
85
>38
>95
92
>96
>60
10
—
93
>88
—
>97
Inlet
74
5
<0.5
<0.5
<2
26
<3
<0.2
2.5
42
1
9
31
11
<20
Ash pond effluent
Observed removal
Outlet efficiency,%
99
20
—
—
__
31
—
—
20
24
__
22
39
>82
' < - Designates concentration below detection limit.
Values are in ppm.
-------
zinc all exhibited lower degrees of removal with ferrous sulfate
added to lime. As most of the concentrations were very low,
definitive conclusions cannot be made from the data.
A comparison of Tables 6-6 and 6-9 (Plant 5409) shows
that, in most cases, the combination of lime and ferrous sulfate
had equivalent or higher apparent removal efficiencies than lime
alone. For instance, the apparent removal of silver from cooling
tower blowdown was more than doubled, from 44 percent to 93 per-
cent, by using both lime and ferrous sulfate as opposed to lime
only. Although the removal eff,ect of this chemical combination
on other trace elements was not nearly so dramatic, the result-
ing removal efficiencies were higher. The only two exceptions
were copper in the ash pond effluent and nickel in the cooling
tower blowdown, both of which registered lower removal efficien-
cies for lime and ferrous sulfate. The apparent increase in the
concentration for vanadium in the cooling tower blowdown was
traced to contaminated filter paper.
6.2.3 Lime Plus Ferric Sulfate Precipitation
Ferric sulfate was added to lime to evaluate the effec-
tiveness of this combination in removing arsenic and chromium.
In these cases only arsenic and chromium were evaluated in the
effluent. For Plant 5604, the reduction in arsenic was similar
for both lime and lime plus ferric sulfate. Due to the low con-
centrations of arsenic and chromium in the influent streams, it
was not possible to evaluate ferric sulfate performance.
For Plant 1226, arsenic removal was not higher with
the combination than for lime alone. The arsenic concentration
in the inlet was low for both cooling tower blowdown (4 ppb) and
ash pond effluent (9 ppb). Chromium was reduced to the detection
71
-------
limit (2 ppb) for the ferric sulfate tes-s, while no removal was
observed for lime alone. As in the case of arsenic, the inlet
concentrations of chromium were very low, 4 ppb in the cooling
tower blowdown and 6 ppb in the ash pond effluent.
At Plant 5409, ferric sulfate reduced the concentra-
tions of arsenic and chromium to their respective detection
limits (1.0 ppb and 2.0 ppb). This was an improvement over lime
only for the case of chromium in the cooling tower blowdown.
Chromium in the ash pond effluent was below the detection limit.
As a direct result, nothing conclusive can be said about the
effectiveness of this chemical in this application.
6.2.4 Lime Plus Sodium Sulfide Precipitation
A study similar to the test with ferric sulfate was
performed with sodium sulfide. This test was developed to
examine removal enhancement for cadmium and mercury.
At Plant 5604, cadmium and mercury were reduced to less
than their detection limits, 0.5 ppb and 0.2 ppb, respectively.
However, the results were the same with lime alone. As the
inlet concentrations of cadmium and mercury were very low, 1 ppb
or less in all cases, it was impossible to evaluate the removal
effectiveness of this chemical for these conditions.
At Plant 1226, the cadmium concentration was nearly
reduced to the detection limit, 0.5 ppb, with sodium sulfide.
In the case of lime only, the results were inconclusive as the
measured outlet concentration was greater than the inlet concen-
tration for the cooling tower blowdown. No removal using sodium
sulfide was observed for the ash pond effluent. Mercury was at
the detection limit for both inlet streams.
72
-------
At Plant 5409, lime plus sodium sulfide was effective
in reducing the concentrations of cadmium and mercury to the
detection limits. However, the results were the same as with
lime precipitation. As the inlet concentrations of the two
metals were low, less than 1 ppb in all cases, it is impossible
to say conclusively what effect sodium sulfide has on removal
of these metals.
6.3 REVERSE OSMOSIS
A portable reverse osmosis (RO) unit was used for the
evaluation of this technology at each of the test sites. The
unit was operated at each sample site for approximately two hours
to simulate continuous operation. During the first hour conduc-
tivity and pH measurements were made to determine steady state
operation. Samples of the RO unit effluent were then taken dur-
ing the second hour. Conductivity and pH measurements made dur-
ing this sampling period indicated that, in general, there were
no significant variations resulting from fluctuations in feed
compositions. The only exception to this observation occurred
while sampling the cooling tower blowdown at Plant 1226. The
samples at this location were obtained during shock chlorination
and the quality of the water did vary over the testing time
period.
The unit was designed to operate at 200 psi and 50
percent rejection, producing a clean water stream and a concen-
trated reject stream at a rate of 0.28 gallons per minute for
each stream. A hollow fiber polyamide membrane was used in the
unit. As the membrane is sensitive to certain water conditions,
such as those producing scaling, fouling or chemical attack, pre-
liminary tests were made on the wastewater streams to determine
the need for pretreatment. Tests were run with a Hach test kit
73
-------
and a fouling index kit supplied by the manufacturer of the
unit. Measurements were made of pH, turbidity, fouling index,
free chlorine, iron and copper as the membrane is sensitive to
certain extreme conditions associated with these.
Since the unit was in actual operation for such a
short time, the primary reason for the pretreatment tests was
to give some basis for evaluating the applicability of this
technology under actual operating conditions. The pretreatment
tests were conducted at each sampling site; however, only one
stream, the cooling tower blowdown at Plant 5409, required pre-
treatment. The suspended solids loading in this stream was high.
6.3.1 Organic Analysis
The results of the chemical analyses for organic com-
pounds in the effluent (product) stream from the reverse osmosis
unit are presented in Tables 6-10 through 6-12. As discussed in
Section 5, the wastewater streams at all the plants studied
were relatively free of any priority organics. In the vast
majority of the cases where compounds were observed, the concen-
tration levels were very low. Only a few compounds of interest
were confirmed as present in the inlet streams by the GC-MC
analyses. As a direct result of the low inlet concentrations,
it was not possible to observe any significant pollutant removal
by use of the reverse osmosis unit.
The results of the analysis for removal of organic com-
pounds by reverse osmosis for Plant 5604, presented in Table 6-10,
indicate little about the suitability of this technology. The
cooling tower blowdown and the ash pond effluent were very nearly
void of priority organics. Measurable concentrations of benzene
and toluene were observed in both streams. Slight removal of
74
-------
TABLE 6-10.
PLANT 5604: REMOVAL OF ORGANIC COMPOUNDS BY REVERSE OSMOSIS
(Concentration in ppb)a
Compounds
Cooling tower blowdown
Observed removal
Inlet Outlet efficlency,%
Ash pond effluent
Observed removal
Inlet Outlet efficiency,%
Chloroform
Benzene
Toluene
Ethylbenzene
Phenol f
Dimethyl phthalate
Diethyl phthalate
Fluor an thene
50
75
*
2.0
,A blank in the table signifies that a compound was not identified as being present.
< - Designates concentration below detection limit.
/ - Indicates that presence of this compound was confirmed by GC-MS.
Evaporated - redissolved residue.
- Not Analyzed.
Phuhalates cannot be quantified due to sample contamination.
-------
toluene, 13 percent, was observed for the cooling tower blowdown
stream. However, considering the possible errors in measuring
such low concentrations, the inlet and outlet values are very
nearly the same. Some removal of benzene and toluene was
observed for the ash pond effluent tests, 30 percent and 20 per-
cent, respectively. Again, given the very low concentration
levels and the possible errors of measurement, these removal
efficiencies do not support definitive conclusions.
The results of the analysis for Plant 1226 are presen-
ted in Table 6-11. The untreated cooling tower blowdown at this
plant contained significant concentrations of bromoform and
dibromochloromethane, 154 ppb and 59 ppb, respectively. Nearly
complete removal of these compounds was observed in the outlet
from the RO unit. Both were reduced to their detection limit
or lower. The grab sample used to quantify the inlet conditions
was taken during shock chlorination, while the outlet samples
from the RO were taken considerably later. During the operating
time period, the inlet concentration could have changed, result-
ing in actual inlet concentrations less than the values presen-
ted in the table. No other compounds were observed in any quan-
tity for either wastewater source with the exception of bromo-
dichloromethane in the cooling tower water. The bromodichloro-
methane was not identified as being present in the RO unit
product stream.
The organic analyses for Plant 5409 are presented in
Table 6-12. Removal of three compounds from the cooling tower
blowdown and one compound in the ash pond effluent was observed.
All concentrations of these compounds in the two inlet streams
were less than 4 ppb. At these concentration levels, the differ-
ences between the measured inlet and outlet concentrations are
within the error limits; however, removal was observed in each
76
-------
TABLE 6-11. PLANT 1226: REMOVAL OF ORGANIC COMPOUNDS BY REVERSE OSMOSIS
(Concentrations in ppb)a
Compounds
Cooling tower blowdown
Observed removal
Inlet Outlet efficiency,^
Ash pond effluent
Observed removal
Inlet Outlet efficiency, %
Hexachlorocyclopenta-
diene
4-Chlorophenyl ether
4-Bromophenyl ether or
a BHC
Y BHC or 6 BHC (benzene-
hexachloride)
Aldrin
Chloroform
1,1,1 Trichloroethane
Bromodichloromethane
Trichloroethylene
Dibromochloromethane
Bromoform
Tetrachloroethylene
Benzene
Toluene
Ethylbenzene
Phenol
Dimethyl phthalate6
Diethyl phthalate
88
>98
>99
>74
<2
2.0
1.0
1.5
<4
<2
N/A
*
*
-------
TABLE 6-11.
(Cont.)
Cooling tower blowdown Ash pond effluent
Observed removal Observed removal
Compounds Inlet Outlet efficiency,% Inlet Outlet efflciency,%
Fluor an thene
Butyl benzyl phthalate
Bis (2 ethylhexyl)
Phthalate or 1,2
Benzanthracene or
Chrysene *
Di-n-butyl phthalate *
2.7
*
*
*
*
*
* *
aA blank in the table signifies that a compound was not identified as being present,
< - Designates concentration below detection limit.
oo °/ - Indicates that presence of this compound was confirmed by GC-MS.
N/A - Not Analyzed.
ePhthalates cannot be quantified due to sample contamination.
-------
TABLE 6-12. PLANT 5409: REMOVAL OF ORGANIC COMPOUNDS BY REVERSE OSMOSIS
(Concentrations in ppb)a
Cooling tower blowdown Ash pond effluent
Observed removal Observed removal
Compounds Inlet Outlet efficiency,% Inlet Outlet efficiency,%
1,3 Dichlorobenzene 1.0 1.0
Bis (2-Chloro-isopropyl)
ether or Bis (2-chloro- ,
ethyl) ether 1.2 >17
Hexachlorocyclopenta-
diene <1 <1
4 Bromophenyl ether or
a BHC <1 <1
Y BHC or_ 6 BHC (benzene-
hexachloride) 1.3 — <1
Aldrin <1
Heptachlor epoxide <1 —
a Endosulfan <1
Dieldrin £r DDE <1
Endrin <1 — <1
DDT <1
1,1 Dichloroethane <1
Chloroform 2.4/° <1 >58 <1 <1
1,2 Dichloroethane <1 —
Bromodichloromethane 2.6/ >62
Trichloroethylene
Dibromochloromethane
Benzene 1.5/ <1 >33 l.O/
-------
00
o
TABLE 6-12.
(Cont.)
Compounds
Toluene
Ethylbenzene
Phenol
Dimethyl phthalate6
Diethyl phthalate
Fluoranthene
Butyl benzyl phthalate
Bis (2 ethylhexyl)
phthalate or 1,2
benzanthracene or
chrysene
Di-n-butyl phthalate
, A blank in the table
Cooling tower blowdown
Observed removal
Inlet Outlet efficiency, % Inlet
-------
case. Toluene, present in the ash pond water, was observed in
higher concentrations after the RO treatment. Nonetheless,
some removal was observed as can be seen for chloroform (58%),
benzene (33%) and bromodichloromethane (62%)
6.3.2 Inorganic Analysis
The results of the chemical analyses of inorganic
compounds in the product water streams of the reverse osmosis
(RO) unit are presented in Tables 6-13 through 6-15. As
opposed to the organic analyses where no important organic
t
species were present, several of the important inorganic
species were detected in the inlet stream. As a result, it
was possible to address removal efficiencies for these compounds
The results of the analysis for inorganics in the
product stream of the RO unit at Plant 5604 are presented in
Table 6-13. In general, copper, vanadium, and zinc were pres-
ent in significant concentrations. The observed removal effi-
ciencies for copper were 82 percent and 89 percent for cooling
tower blowdown and ash pond effluent, respectively. For zinc
removal, the RO unit was 99 percent effective for cooling tower
blowdown and 82 percent effective for the ash pond effluent.
The results for vanadium differed in magnitude; in the cooling
tower blowdown test only an 8 percent reduction was observed,
while for the ash pond effluent 81 percent of the vanadium was
removed. It is not known why this large difference occurred.
The other metals were below 10 ppb in the inlet water. The RO
unit removed portions of a few of these metals. In a few cases,
the measured outlet concentration was higher than the inlet.
Of those, only the arsenic and lead concentrations in the cool-
ing tower blowdown appeared significant. The cyanide concen-
tration in the ash pond was significant (22 ppb). The RO unit
reduced cyanide 82 percent.
81
-------
TABLE 6-13.
co
PLANT 5604: INORGANIC COMPOUND REMOVAL EFFICIENCIES FOR REVERSE
OSMOSIS (Concentrations in ppb unless otherwise noted)3
Cooling tower blowdown
Arsenic
Antimony
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Inlet
7
5
<0.5
<0.5
<2
180
<3
<0.2
6
<2
3
<1
24
. 780
Outlet
49
2
<0.5
2
2
32
20
<0.2
0.5
<2
4
<1
22
<2
Observed removal
efficiency,%
__
60
—
—
—
82
—
—
>92
—
—
—
8
>99
Total Organic CarbonD <20
CN-
pH
' < - Designates
3
6.9
6
concentration below
detection limit.
Inlet
<1
6
2.5
1
4
80
<3
<0.2
9.5
3
5.5
<1
27
300
<20
22
5.6
Ash pond
Outlet
<1
3
5
<0.5
<2
9
<3
<0.2
<0.5
<2
2
<1
5
53
4
effluent
Observed removal
ef f iciency,%
50
—
>50
>50
89
__
• >95
>33
64
—
81
82
82
-------
The results of the analyses for inorganics in the
product stream of the RO unit at Plant 1226 are presented in
Table 6-14. Only copper, vanadium and zinc were present in the
inlet water at levels higher than 10 ppb. For these compounds,
the removal performance varied. Approximately 79 percent of the
copper was removed from the cooling tower blowdown, while only
29 percent of the copper in the ash pond effluent was removed.
The outlet concentration for vanadium from treatment of cooling
tower blowdown was significantly higher than the inlet. This
increase could have been caused by time variability of the con-
centration of vanadium during sampling. About 82 percent of the
vanadium was removed from the .ash pond effluent. Greater than
93 percent of the zinc was removed from the cooling tower blow-
down, while a zinc reduction of greater than 71 percent was
observed for the ash pond effluent. The inlet zinc concentra-
tion for the ash pond was only 7 ppb, however. The results for
the other species varied from instances where some removal was
observed to instances where higher effluent than inlet concen-
trations were observed. The observed inlet concentrations for
these species were low.
The results of the analysis for inorganics in the
product stream of the RO unit at Plant 5409 are presented in
Table 6-15. Several species were present in both the cooling
tower blowdown and ash pond effluent at this plant. Chromium,
copper, lead, silver, vanadium and zinc were all present in the
cooling tower water in concentrations above 10 ppb. Arsenic,
copper, selenium, vanadium and zinc were present in the ash pond
effluent in concentrations greater than 10 ppb. As at the other
plants, the removal performance was not consistent. About 92-
percent removal of copper was accomplished in the cooling tower
blowdown test, while only 65-percent removal was observed for the
ash pond effluent. The inlet concentrations for these water streams
were different by an order of magnitude, however. This case
83
-------
TABLE 6-14.
GO
PLANT 1226: INORGANIC COMPOUND REMOVAL EFFICIENCIES FOR REVERSE
OSMOSIS (Concentrations in ppb unless otherwise noted)a
Cooling tower
Arsenic
Ant imony
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanad ium
Zinc
Total Organic
CN-
PH
Inlet
4
7
<0.5
1.8
5
47
3
0.2
6.0
<2
0.7
<1
27
26
Carbonb <20
5
6.8
blowdown
Ash pond effluent
Observed removal
Outlet efficiency,/? Inlet
75
—
—
—
>60
79
>0
50
—
14
—
—
—
>93
80
9
7
<0.5
2.0
6
14
4
<0.2
5.5
8
0.5
<1
78
7
<20
<1
9.1
Observed removal
Outlet efficiency,%
1
<1
<0.5
1.3
<2
10
<3
<0.2
5.0
2
<0.2
<1
14
<2
<20
8
89
>86
—
35
>67
29
>25
—
9
75
>60
—
82
>71
—
1< - Designates concentration below detection limit.
Values are in ppm.
-------
GO
Ul
TABLE 6-15. PLANT 5409: INORGANIC COMPOUND REMOVAL EFFICIENCIES FOR REVERSE
OSMOSIS (Concentrations in ppb unless otherwise noted)3
Cooling tower blowdown
Inlet Outlet
Arsenic
Ant imony
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Total Organic Carbonb
CN~
PH
85
>38
>95
92
>96
>60
10
—
92
50
—
>97
>5
defection limit .
74
5
<0.5
<0.5
<2
26
<3 ~
<0.2
2.5
42
1
9
31
11
<20
13
6.7
Ash pond
effluent
Observed removal
Outlet efficiency.%
<1
3
<0.5
<0.5
<2
9
7
<0.2
1.5
6
1
<1
21
<2
<20
10
>99
40
—
—
—
65
—
—
40
86
0
>89
32
>82
—
23
Values are in ppm.
-------
illustrates the dependence of removal efficiency on inlet con-
centration levels. The RO unit had very little effect on vana-
dium, with a higher outlet than inlet concentration for the
cooling tower and only a 32-percent vanadium removal for ash
pond effluent being observed. The removal of zinc was greater
than 97 percent and 82 percent for cooling tower blowdown and
ash pond effluent, respectively. The most dramatic result of
the RO tests was over 99 percent removal of arsenic from the
ash pond effluent.
6.4 VAPOR COMPRESSION DISTILLATION
The evaluation of vapor compression distillation as a
control technology was conducted on an operating unit at Plant
3009. The unit treated wastewater from sources throughout the
plant. This included some waste flow from the cooling water
system and ash pond.
The primary intent of this evaluation was to determine
secondary emissions of priority pollutants from the VCD unit.
The unit has three major liquid streams (inlet, product, and
brine reject) and a gaseous vent stream. The three major liquid
streams were analyzed for inorganics and organics, with both a
solid and liquid phase analysis for the concentrated brine.
Time limitations prevented use of the GC-MS analysis to posi-
tively identify compounds that were tentatively identifed by the
GC. For this reason, the data are presented exactly as analyzed
by the GC.
An attempt was made to sample the deaerator vent for
volatile organic and inorganic compounds. The method used to
sample for organics involved drawing a measured amount of vapor
through a Tenax column to be analyzed for volatile organics.
86
-------
Unfortunately, water vapor in the vent gas caused swelling of
the Tenax resin, preventing passage of the gas so that analysis
of volatile organics was not possible. The vent was also sampled
with a gold amalgamation trap designed to trap mercury for
analysis.
6.4.1 Organic Analysis
The results of the analysis for organic compounds in
the three liquid streams of the VCD unit are presented in
Table 6-16. The concentration levels measured by the GC were
generally low. These data are presented only to demonstrate
that organics were not present in significant concentrations,
and therefore no conclusions about the effectiveness of this
technology can be made.
6.4.2 Inorganic Analysis
The results of the analysis for trace inorganic species
are presented in Table 6-17. The streams covered include the
inlet, the product, and the brine reject. The brine reject was
a two-phase solution containing a dense brine phase and a solid
phase. The two phases were separated and analyzed.
The concentrations for beryllium, cadmium, mercury,
selenium, and thallium were low in both the inlet and the pro-
duct. The VCD unit served to reduce the concentrations of cop-
per, arsenic, zinc, and vanadium.
87
-------
TABLE 6-16. PLANT 3009: REMOVAL OF ORGANIC COMPOUNDS BY
VAPOR COMPRESSION DISTILLATION (VCD)
(Concentrations in ppb)a
VCD VCD VCD
Compound Feed Product Brine
b
Dimethyl phthalate *
Diethyl phthalate *
Bis (2 ethylhexyl) phthalate
or 1,2 benzanthracene or
chrysene *
Di-n-butyl phthalate * *
c
Pentachlorophenol <1 <1 <1
Phenol 1.3 8.7 14.8
1,3 Dichlorobenzene <1
Hexachloroethane or 1,2
dichlorobenzene <1
Bis (2-chloro-isopropyl)
ether or bis (2-chloro-
ethyl) ether <1
1,2,4 Trichlorobenzene or
hexachlorobutadiene <1
Hexachlorocyclopentadiene <1 <1 <1
4 Bromophenyl ether or
a BHC <1
Y BHC or 5 BHC (benzenehexa-
chloride) <1 <1
Heptachlor or g BHC <1 <1
Aldrin <1
a Endosulfan <1
aA blank in the table signifies that a compound was not identified as
.being present.
Phthalates cannot be quantified due to sample contamination.
c< - Designates concentration below detection limit.
-------
TABLE 6-17.
CO
vo
PLANT 3009: INORGANIC COMPOUND ANALYSIS OF WATER SAMPLES
FROM THE VCD UNIT (data in ppb unless otherwise noted)3
Sample stream concentrations
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
CN~
TOC (ppm)
Inlet
7
49
<0.5
<0.5
5
2,700
7
1.5
2.5
<2
15
<1
1,000
910
24
29
Product
3
<1
<0.5
<0.5
<1
10
<3
2
1
<2
2
<1
590
6
1.9
<20
Brine liquid
150
96
4
470
<1
31,000
1,600
2"
690
<2
1,200
2,000
680
3,300
Brine solid
1,000
15,000
110
1,000
38,000
270,000
8,400
1
680
<2
3,400
1,000
11,000
220,000
- Designates concentration below detection limit.
-------
The deaerator vent vapors were analyzed for mercury
as explained earlier. The analysis of the trap contents pro-
duced a measured concentration of 27 ± 10 mg of mercury per
liter of the gas entering the trap. As no accurate exhaust
flow rates for the vent are available, the exact concentration
and mass flow rate of mercury cannot be determined.
90
-------
REFERENCES
1. Colley, J. D, Assessment of Technology for Control
of Toxic Effluents From the Electric Utility Industry,
final report.EPA Contract No. 68-02-2608, Task 9,
Radian Corp., June 1978.
2. National Academy of Engineering. Water Quality
Criteria 1972. EPA-R3-73-033. EPA, Washington,
D.C., 1973.
3. Rice, James K. and Sheldon D. Strauss. Water
Pollution Control in Steam Plants. Power 121(4):
SI-0, 1977.
91
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APPENDIX
TEST PLANS AND ANALYTICAL PROCEDURES
FOR THE EVALUATION OF WASTEWATER
TREATMENT TECHNOLOGIES FOR THE
STEAM-ELECTRIC POWER INDUSTRY
A-i
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CONTENTS
Page
List of Figures A-v
List of Tables A-vi
1.0 Prefield Testing, Field Procedures, and Process
Descriptions for Treatment Technologies A-l
1.1 Introduction ' A-l
1.2 Procedure A-2
1.3 Chemical Precipitation A-3
1.3.1 Sampling Strategy A-4
1.3.2 Equipment A-4
1.3.3 Test Procedure A-7
1.3.3.1 Preliminary Lab Testing A-7
1.3.3.2 Field Testing A-19
1.4 Vapor Compression Distillation A-21
1.4.1 Sampling Strategy.. A-21
1.4.2 Equipment A-22
1.5 Activated Carbon A-22
1.5.1 Sampling Strategy A-24
1.5.2 Equipment A-24
1,5.3 Test Procedure A-26
1. 6 Revers e Osmos is A- 2 7
1.6.1 Sampling Strategy A-27
A-ii
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CONTENTS (Continued)
Page
1.6.2 Equipment A-28
1.6.3 Test Procedure A-31
2.0 Analytical Procedure for Analysis of Organics A-33
2.1 Sample Collection Procedure for GC and
GC-MS Analytical Methods A-33
2.1.1 Bottle Preparation, Packing, and
Shipment A- 34
2.1.2 Sampling Technique and Sample
Preservation A-35
2.1.3 Discussion A-40
2.2 Methods of Analysis for Organic Compounds A-42
2.2.1 Organic Analysis by Gas
Chromatography A-42
2.2.1.1 Instrumentation A-45
2.2.1.1.1 Hall Electrolytic
Conductivity Detector A-45
2.2.1.1.2 Flame lonization
Detector A-46
2.2.1.1.3 Field Purge Unit (FPU) A-46
2.2.1.1.4 Desorption Device A-47
2.2.1.2 Ins trument Operating
Parameters A-47
2.2.1.2.1 Purgeables A-49
2.2.1.2.2 Base/Neutral
Extractables A-50
2.2.1.2.3 Acid Extractables A-51
A-iii
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CONTENTS (Continued)
Page
2.2.1.3 Sample Analysis and Data
Interpretation A-52
2.2.2 Mass-Spectral Analyses A-57
2.2.2.1 Instrumentation A-59
2.2.2.2 Sample Analyses and Data
Interpretation. A-60
3.0 Analytical Procedure for Analysis of Inorganics A-66
3.1 Introduction A-66
i
3.2 Sampling A-67
3. 3 Analytical Methods A-69
3.3.1 Digestion Methods A-70
3.3.2 Trace Metals Analysis A-71
3.3.3 Cyanide and TOG Analysis A-73
3.4 Results and Error Analysis A-75
References A-80
A-iv
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FIGURES
Number Page
A-l Hach floe tester, model 15057 A-16
A-2 Simplified system schematic of a brine
concentrator A-23
A-3 An outline of field sampling procedure and
sample preservation A-36
A-4 Field purge unit (FPU) A-48
A-5 Example chromatogram of a typical GC sample
analysis A-58
A-6 Computerized printout of a mass spectral search
for purgeable organics in a wastewater sample.... A-62
A-7 Computerized printout of mass spectrum at Point
339 for dibromochloromethane A-64
A-8 Inorganic analytical scheme A-68
A-9 Cyanide distillation apparatus A-74
A-v
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TABLES
Number Page
A-l Sampling Strategy for Chemical Precipitation A-5
A-2 Chemical Precipitation Equipment List A-6
A-3 Removal by Lime Treatment a.t Various pH's A-10
A-4 Removal by Ferric Sulfate and Lime Precipitation... A-10
<
A-5 Effect of Ferrous Sulfate on Lime Precipitation. .. A-ll
A-6 Removal by .Alum and Lime Precipitation A-12
A-7 Removal by Sodium Sulfide, Carbon Dioxide and
Lime Precipitation A-12
A-8 Comparison of Precipitating Agents on Lime
Precipitation A-13
A-9 Recovery Study of Precipitation Tests A-13
A-10 Results of Precipitation Tests A-15
A-ll Preservation Techniques for Inorganic Samples A-22
A-12 VCD Sampling Equipment List A-22
A-13 Activated Carbon Field Equipment List A-25
A-14 Reverse Osmosis Field Equipment List A-29
A-15 Inlet Specification for DuPont Polyamide
Membrane A-30
A-16 Maximum Contaminant Levels for Organic Chemicals... A-43
A-17 Organic Compounds Identified for GC Analysis A-44
A-18 EPA Consent Decree List of "Unambiguous Priority
Pollutant" Organic Compounds A-55
A-vi
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TABLES (Continued)
Number Page
A-19 Preservatives for Analyses A-69
A-20 Analytical Methods for Detection of Metals A-71
A-21 Analytical Wavelengths Atomization Program for
Elements Analyzed A-72
A-22 Comparison of NBS Water Sample SRM 1643 with
Radian Results A-76
A-23 Detection Limits and Accuracy of Data for
Inorganic Analyses A-77
A-24 Water Quality Criteria A-79
A-vii
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1.0 PREFIELD TESTING, FIELD PROCEDURES, AND PROCESS
DESCRIPTIONS FOR TREATMENT TECHNOLOGIES
1.1 INTRODUCTION
The objective of this program was to assess available
treatment technologies for control of priority pollutants in
wastewater streams from the electric utility industry. The
treatment evaluation program outlined in this Appendix is de-
signed to determine if the chosen treatment technologies will
remove the priority pollutants identified in the wastewater
streams. Four treatment technologies were selected for eval-
uation in the utility industry:
1) Chemical precipitation
2) Vapor compression distillation
3) Carbon adsorption
4) Reverse osmosis
The study was to screen the wastewater controls in
field tests to determine if they reduced priority pollutants to
acceptable levels in plant effluents. Therefore, the study was
limited to a bench-scale analysis performed on actual waste
streams in four power plants. Due to the bench-scale nature and
very short run times of the evaluations, no design or cost data
for full scale applications were developed.
The Appendix describes the test plans developed and
the analytical procedures used to quantify the priority pollutants
in the plant water streams. Descriptions of the four treatment
technologies under investigation are presented. A description of
the general approach used to determine the performance of the
treatment technologies is also presented.
A-l
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1.2 PROCEDURE
The approach used to evaluate the controls involved
three steps. These steps are as follows:
1) Design and construction of bench-scale
equipment for the treatment technologies
2) Development of a testing program
and analytical procedures
3) Field testing of treatment technologies
The development of the bench-scale designs for the
treatment systems involved review of available design informa-
tion for activated carbon adsorption and chemical precipitation.
Literature sources and commercial vendors of these systems were
contacted to obtain information. The information collected
focused on the problem of assessing the technologies for re-
moval of pollutants at the anticipated low concentrations.
This was especially important in the design of activated carbon
columns. A standard approach to evaluating carbon adsorption
involves the use of batch isotherms. This approach is not
practical for waste streams with organics in the parts per billion
(ppb) concentration range. Therefore, carbon columns were built
using accepted design practices for removal of small quantities of
organic materials to evaluate the performance of carbon adsorp-
tion. These were used to determine whether carbon adsorption
could remove the priority organics in the very low levels of con-
centration expected in the study. However, an adequate assess-
ment of the overall performance of carbon adsorption, such as
determining breakthrough, was not provided due to the lack of
sufficient time to collect the data.
A-2
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The evaluation of chemical precipitation used a stan-
dard approach to determine settling rates and removal efficiencies
for trace levels of the priority metals. Lime precipitation was
evaluated with and without additives. Sulfide precipitation was
also evaluated.
The evaluation of reverse osmosis (RO) was conducted
using a bench-scale unit to determine the suitability of
RO as a pretreatment step prior to the other treatment technol-
ogies. The ability of the RO unit to concentrate the pollutants
in the reject stream was also evaluated.
The evaluation o'f vapor compresssion distillation (VCD)
was performed on an installed and operating unit at a power
plant. It was not considered practical to design or purchase
a bench-scale unit with the same capabilities. The primary pur-
pose for evaluating the VCD unit was to determine the priority
pollutants in secondary emissions from the units.
1.3 CHEMICAL PRECIPITATION
The objective of this test plan was to provide data
necessary to examine the feasibility of chemical precipitation
for removing the following inorganic priority pollutants:
1) antimony 9) mercury
2) arsenic 10) nickel
3) beryllium 11) selenium
4) cadmium 12) silver
5) chromium 13) thallium
6) copper 14) zinc
7) cyanide 15) vanadium
8) lead
A-3
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The effectiveness of the treatment for reducing total organic
carbon (TOG) was also examined. The streams tested were:
1) cooling tower blowdown
2) ash pond effluent
Lime was the primary precipitating agent examined. Sodium sul-
fide was tested for its ability to reduce cadmium and mercury
since these metals may not be removed by lime treatment alone.
Addition of ferric and ferrous sulfate with lime was also tested
to examine their effect upon metals removal due to coprecipita-
tion mechanisms.
1.3.1 Sampling Strategy
Water samples were taken from cooling tower blowdown
and ash pond effluent. The samples were analyzed for the pri-
ority pollutants. These samples represented the inlet condition
to the treatment process. One sample from each stream was tested
with lime as the precipitating agent. Duplicate samples from
each stream were tested with lime, lime with ferric and ferrous
sulfate and sodium sulfide.
The performance of chemical precipitation for pollu-
tant removal was determined by analyzing the treated samples for
residual concentrations of the pollutants being investigated, as
well as TOG. Table A-l summarizes the testing strategy.
1.3.2 Equipment
The equipment used for testing with chemical precipita-
tion is listed in Table A-2.
A-4
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TABLE A-l. SAMPLING STRATEGY FOR CHEMICAL PRECIPITATION
Operation
Number of
Samples per
Stream
Number of
Elements
Analyzed for
Notes
Lime precipitation
15
Complete analysis
Lime precipitation
plus ferric sulfate
15
Complete analysis
Lime precipitation
plus ferrous sulfate
Analysis for chromium and
arsenic
Lime/sodium sulfate
precipitation
Analysis for mercury and
cadmium
R;iw water analysis
15
Complete analysis
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TABLE A-2. CHEMICAL PRECIPITATION EQUIPMENT LIST
Jar test apparatus
pH meter
Graduated cylinder - 1 liter
Filtering apparatus
Filter paper, 43 Whatman
Precipitating reagents
Lime
Sodium sulfide
Coagulant aids
Ferric sulfate
Ferrous sulfate
Betz 1100 Floe
Bottle of nitric acid - double distilled
Magnetic stirrer
Pipets
A-6
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1.3.3 Test Procedure
1.3.3.1 Preliminary Lab Testing--
The objective of the controlled laboratory testing
program was to evaluate different precipitating methods before
actual field testing was begun. The methods were to be similar
to techniques used in public or industrial wastewater treatment
facilities. The precipitation methods were tested for effective-
ness of removing trace metals from utility wastewater streams.
Water treatment by chemical precipitation depends upon
the type of contaminants present, the type and dosage of coagu-
lants and coagulant aids, and the chemical characteristics of
the water, i.e., pH, temperature, ionic strength, etc. Impur-
ity removal is accomplished by any of the following mechanisms:
1) Precipitation - the formation of insoluble
species by chemical addition
2) Coprecipitation - the formation of a solid
solution of two or more species of similar
size, electrical charge, or crystal morphology
3) Inclusion - the physical entrapment of impur-
ities within the precipitate during the
precipitation process
4) Adsorption - the adsorption of ions by
active sites on the surface of a precipitate
5) Coagulation the formation of a flocculent
mass by the aggregation of fine suspended
precipitate particles
A-7
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The purpose of coagulant aids is to remove impurities
that are too small to be removed by gravity settling. A variety
of coagulants and settling aids is available. The control of pH
and the proper choice of precipitation aids are the major factors
in a successful water treatment process.
Lime (CaO or Ca(OH)2) and soda ash (Na2C03), are the
two most common additives used for basic pH control. With soda
ash there is no increase in hardness for the treated water; how-
ever, an increased potential for corrosion is observed. Lime is
less expensive and also has the advantages of forming precipi-
tates of CaC03 and CaSO^. Metal oxide formation is most effi-
cient with the pH between 10.5 and 12.5. Lime was chosen as the
pH control agent. The removal of metal species as xoides will
be enhanced by coprecipitating them with CaC03 and CaSOi,.
Aluminum, ferric and ferrous salts are the most widely
used coagulants. Alum, potassium aluminum sulfate, is the stan-
dard coagulant used in wastewater treatment. Effective coagula-
tion for alum is in the pH range 5.5 to 8.0. Alum reacts with
the natural alkalinity of the water to produce carbon dioxide.
This increases the corrosiveness of the water, which is undesir-
able.
Iron salts, though more expensive, are very effective
in color removal and can be applied over a wider pH range than
alum. Copperas (ferrous sulfate) is normally added with lime to
form a precipitate of ferric hydroxide. Ferrous sulfate has the
advantage of reducing hexavalent chromium to trivalent chromium
which can then be precipitated as the metal oxide.
Both ferric sulfate and ferric chloride are used as
coagulants alone or with lime. The optimum pH range is wide, 4
to 9, and the floes formed are quick-setting. Ferric chloride
A-8
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is more efficient; however, it must be handled with corrosion-
resistant equipment.
Some metals will not form oxides or hydroxides that
can be precipitated. Metal sulfides, usually generated with
either sodium sulfide or hydrogen sulfide, are generally less
soluble in basic solution than the corresponding oxide. Sulfide
addition can aid in the removal of certain metals, such as lead,
mercury, and cadmium. These precipitates can be coagulated with
the lime precipitation method.
Impurities can be removed by adsorption at active
sites of the precipitatev Polyelectrolytes are water-soluble,
high-molecular weight polymers. In solution, polyelectrolytes
disassociate forming large, highly charged ions. There are
three types of polyelectrolytes available: negatively charged
or anionic polyelectrolytes, positively charged or cationic, and
those that form both positive and negative charges, which are
erroneously called "nonionic." Polyelectrolytes, because of the
large size, also increase the settling rate.
Precipitation Results of Artificial Wastewater Sample--
An artificial wastewater sample was prepared by adding
standard amounts of arsenic, chromium, copper, nickel, selenium,
and zinc. The prepared samples contained metal concentrations
of 3 ppm. These levels allowed for rapid analysis by atomic
absorption using standard flame techniques. Removal efficien-
cies were calculated by the formula:
C - Cr
% Removal = -^ x 100 (1-1)
Co
where C is concentration of treated water and CQ is concentra-
tion of the untreated water, both for a given compound.
A-9
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Table A-3 presents the data for the effective removal
of metals with changing pH. The pH was controlled by lime addi-
tion. Lime was the only precipitating agent used. As can be
seen, As, Cu, Ni, and Zn are all effectively removed by lime
alone. The pH does not have a significant effect. A slight
removal of Cr is seen at the higher pH level. However, no sig-
nificant removal is seen for Se.
TABLE A-3. REMOVAL 3Y LIME TREATMENT AT VARIOUS pH'S
Final
pH
10.8
11.9
12.3
12.4
Removal Efficiency (7e)
As
88
90
92
95
Cr
3
7
22
18
Cu
99+
99+
86
88
Ni Se
99+ <1
99+ <1
99+ 9
99+ <1
Zn
99+
87
45
82
Two iron salts were tested for the effect on lime re-
moval efficiencies. Various amounts of ferric sulfate were added
to the sample and, then, the pK was raised to 11.5 with lime. A
fast settling floe of ferric hydroxide was formed. Results of the
ferric sulfate tests are shown in Table A-4.
TABLE A-4. REMOVAL BY FERRIC SULFATE AND LIME PRECIPITATION
Ferric Sulfate
Concentration
110
260
510
1100
Final
PH
11.5
11.4
11.1
8.7
Removal Efficiency (7,)
As
97
98
99+
99+
Cr
8
11
13
30
Cu
99+
99+
99+
99+
Ni
99+
99+
99+
99+
Se
21
29
27
83
Zn
99+
99+
99+
99+
The effect of ferric sulfate on the removal of As, Cu, Ni, and
Zn was not significant. Chromium exhibited an increase in
removal efficiency as the concentration of ferric sulfate in-
creased, although the increased efficiency was not large.
A-3.0
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Selenium was removed with better efficiency with ferric sulfate
present than with lime alone. A high removal was seen with a
high concentration of iron.
The concentrations of ferric sulfate used in the lab-
oratory were found to be excessive. For field testing, the con-
centration was lowered to 10 ppm to be consistent with most
large scale treatment processes.
Ferrous sulfate (copperas) is oxidized to ferric hy-
droxide at high pH. Ferrous sulfate can also reduce hexavalent
chromium to trivalent chromium at a low pH. The metal oxide is
precipitated with lime. Table A-5 shows the effect of varying
pH and copperas concentrations on the removal of Cr, As, and Se.
The initial pH of the sample was low enough to allow reduction
of Cr 6 and Cr 3. The removal of selenium with copperas was
low, just as was found with ferric sulfate.
TABLE A-5. EFFECT OF FERROUS SULFATE ON LIME PRECIPITATION
Ferrous Sulfate
(ppm)
100
120
250
260
Final
pH
12.0
11.5
12.0
11.5
Removal Efficiency
As Cr
98 66
98 81
98 91
99 91
(7.)
Se
24
10
13
24
Potassium aluminum sulfate (alum) was added to increase
precipitation rate. Removal efficiencies of As, Cu, Ni, and Zn
were the same as for lime alone. No major removal increase was
observed for chromium and selenium. Table A-6 shows the removal
with lime and alum.
A-ll
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TABLE A-6. REMOVAL BY ALUM AND LIME PRECIPITATION
Alum Concen- Final
tration
84
160
570
1100
(ppni) pH
11.5
11.0
11.1
9.4
As
92
91
92
98
Removal Efficiency (%)
Cr
9
9
17
15
Cu
99+
99+
99+
99+
Ni
99+
99+
99+
99+
Se
<1
4 -
21
21
Zn
88
86
94
99+
Two techniques were employed to remove metals which do
not form insoluble oxides or hydroxides. The samples were brought
to a pH of 11.5 with lime. Sodium sulfide was added to one and
carbon dioxide was bubbled through a second. The final pH of
both was measured. The results of these two techniques are pre-
sented in Table A-7.
TABLE A-7. REMOVAL BY SODIUM SULFIDE, CARBON DIOXIDE AND
LIME PRECIPITATION
Additive
Sodium
Sulfide
CO 2
Additive
(ppm)
50
--
Final
pH
11.6
6.4a
Removal
As
86
89
Cd
99+
59
Cr
20
16
Efficiency
Cu
99+
73
Ni
99+
33
Pb
64
(%)
99+
Se
21
27
Zn
62
39
alnitial, pH = 11.5
A final experiment was performed using the various pre-
cipitating agents at the chosen pH of 11.5. As seen in Table
A-8, ferric sulfate was the most effective agent for overall
removal of the metals tested at the given pH. Ferric sulfate
was effective for all but chromium.
A-12
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TABLE A-8.
COMPARISON OF PRECIPITATING AGENTS
ON LIME PRECIPITATION
Additive Concen- Final
Additive tration (ppm) pH
Alum
Ferric sulfate
Betz 1100
Ferrous sulfate
No additive
130
530
10
250
--
11
11
11
11
11
.4
.1
.3
.3
.9
Removal Efficiency (%)
As
98
99
99
99
87
Cr
18
17
11
87
22
Cu
99+
99+
99+
99+
96
Pb
_ _
99+
65
99+
68
Se
13
24
17
24
<1
A recovery study was performed by analyzing the
treated sample and the precipitate formed. The total metal
found was compared to the amount added. Generally, the amount
found was within the limits of experimental error of the amount
of metal added. In the lime-alum system, more lead was found
after treatment. This was probably due to contamination from
the alum. The recovery results are shown in Table A-9.
TABLE A-9. RECOVERY STUDY OF PRECIPITATION TESTS
Additive
Lime
Lime
Lime
Lime
Lime
+ alum
+ Fe2(SOO3
+ Betz 1100
+ FeSOu
Precipitation
and Synthetic
Final
pH
11.4
11.1
11.3
11.3
11.9
Results
Ash Pond
Cr
88
90
94
85
81
of Cooling
Effluent
Percent Recovered
Cu
87
91
69
92
84
Tower Slowdown
Pb
156
78
59
84
39
A synthetic ash pond sample was prepared by equilibra-
ting bottom ash with deionized water. There was no pH adjustment,
A-13
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Analysis of the raw, as well as the treated sample, revealed
that concentrations were below the determination limits of the
analytical methods used. Removal efficiencies were not calcu-
lated.
A sample of cooling tower blowdown was obtained from
a local gas-fired steam station. This plant adds dichromate to
the system for corrosion control. The raw sample and the treated
sample were analyzed for chromium, mercury, and selenium. As
expected, chromium was the only metal found in large concentra-
tions. Ferrous sulfate, as shown in the control testing, was
effective in the removal of the chromate. Table A-10 presents
the data for the results of the precipitation tests on cooling
tower blowdown and synthetic bottom ash samples.
Experimental Procedure--
Jar test experiments were performed to evaluate the
effect of pH and various precipitating agents on trace metals
removed from water. Water samples of known trace metal concen-
trations were prepared. A sample of cooling tower blowdown was
obtained from a local steam station. Synthetic ash pond efflu-
ent was prepared by mixing a sample of bottom ash from a western
steam station with deionized water. All of the samples were
subjected to various preciptating tests for evalution.
Jar tests were performed to simulate the various stages
of mixing and settling basin activity in water treatment. A Hach
Floe Tester, Model 15057 (Figure A-l), was used for all jar test
procedures. The test apparatus consisted of a 600-ml beaker,
a dasher/mixer, and a low-speed magnetic stirrer. The four
steps of the simulated treatment process were: chemical addition,
flash mixing, flocculation, and settling.
A-14
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TABLE A--10. RESULTS OF PRECIPITATION TESTS
COOLING TOWER SLOWDOWN
Initial
PH
Raw Sample 6 . 5
Treatment
Lime
Lime + FeSOi,
Lime + Alum
Lime + Fez(SOO 3
Lime + NazS
Cr
4 . 2 ppm
Final
PH
11.5
. 11.6
11.4
10.9
11.6
Hg
1 . 4 ppm
Se
< 0 . 5 ppb
Removal Efficiency (70)
Cr
<5
74
24
11
17
Hg
8
<5
<5
14
<5
SYNTHETIC BOTTOM ASH
Cr Hg
Se
Raw Sample
< 0.2 ppm
< 0.5 ppm
<0.5 ppb
All treated samples were below detection limits listed for raw
sample.
A-15
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Figure A-l. Hach Floe Tester, Model 15057
A-16
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Jar Test Procedure--
A sample of water (100 to 500 ml) was placed in a 600-
ml beaker. A magnetic stirring bar was placed in the sample and
the beaker placed on the stirring base. The stirrer was turned
on and the initial pH was then recorded. Aliquots of the pH
control agents and coagulants were placed in the sections of the
dasher/mixer. Flash mixing was simulated by quickly plunging
and twirling the dasher/mixer in the sample. The stirrer timer
was set for 30 minutes to allow for floe formation. The final
pH was measured 20 minutes after flash mixing. Following floc-
culation, the stirring bar was removed and the sample was
allowed to settle for 30 minutes. After settling, the sample
was filtered and preserved for trace metal analysis.
A pH range of 9 to 13 was chosen because of optimum
metal oxide formation in this range. Lime (calcium hydroxide)
was chosen as the pH control agent. Coagulation and precipita-
tion aids chosen were:
1) Potassium aluminum sulfate (alum)
2) .Ferric sulfate
3) Ferrous sulfate (copperas)
4) Sodium sulfide
5) Carbon dioxide
6) Betz 1100
A-17
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Preliminary testing for the optimization of the various
parameters was conducted on the artificial wastewater sample of
known trace metal concentration. Lime was used as the pH con-
trol agent as well as the main coagulant. Experiments were per-
formed to measure the effect of the following on trace element
removal:
1) pH
2) Alum addition
3) Ferric sulfate addition
4) Copperas addition
5) Sulfide addition
6) Carbon dioxide addition
The trace metals used in the preliminary testing were:
copper, nickel, zinc, arsenic, selenium, and chromium. Copper,
nickel, and zinc were chosen because of their typical transition
metal behavior in oxide formations. Arsenic and selenium were
chosen because of their amphoteric characteristics. Chromium
was used because hexavalent chromium, or chromates, are used in
corrosion control and present a problem to water treatment.
Other elements used for certain tests were lead, cadmium, and
mercury.
Treatment processes were applied to the cooling tower
blowdown and ash pond liquor samples. Optimum conditions found
in the previous experimentation were used to treat the samples.
A-18
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Chemical precipitation, with the emphasis on lime
precipitation, can be effective in the removal of most trace
metals from utility waste-water streams. For plant design, an
exhaustive test program needs to be performed using jar tests
and analyses for individual plants and separate streams within
the plant. Several factors are important in determining which
precipitant and under what conditions the precipitation should
be done. Each system will be different and require separate
testing programs to predict the optimum operating parameters.
1.3.3.2 Field Testing--
Field testing of chemical precipitation proceeded as
follows:
1) A 500-ml sample from the cooling tower blowdown
and a 500-ml sample from the ash pond effluent
were analyzed to determine priority pollutant
concentrations, total suspended solids (TSS) ,
total dissolved solids (IDS) and total organic
carbon (TOG). In addition, five more 500-ml
samples were taken from each of the two streams
for precipitation testing.
2) Sample 1 from each stream was used to determine
the quantity of lime which was needed to adjust
500-ml of that stream to a pH of 11.5. A pH
meter and a calibrated pipet were used in a
trial-and-error determination. The lime was
taken from a l-£ standard slurry solution of
Ca(OH)2 and deionized water. The quantity of
lime slurry needed to adjust the sample to a
pH = 11.5 was recorded.
A-19
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3) Sample 2 was used to evaluate the effec-
tiveness of lime precipitation. To this
sample, the predetermined quantity of lime
was added by flash mixing using the
jar test apparatus. The sample was then
slow-mixed on the tester for a 30-minute
period. The solution was then filtered.
Nitric acid was added to the filtrate to
adjust the sample to a pH below 2.0 for
preservation and sealed in a bottle for
analysis later.
4) Sample 3 was used to determine the effect
of ferric sulfate and lime on chromium and
arsenic removal. Ten mg/£ of ferric sul-
fate, measured as iron, was first added to
the sample by flash mixing using the jar test
apparatus. Then, lime was added by flash mix-
ing to adjust the pH to 11.5. After 30 minutes
of slow mixing, the sample was filtered.
The filtrate was adjusted to a pH below
2.0 using nitric acid and sealed in a
bottle for analysis.
5) Sample 4 was used to examine the effect of
ferrous sulfate as a coprecipitating agent
with lime. The same procedure was followed
for this sample as for Sample 3, substituting
ferrous sulfate for ferric sulfate.
6) Sample 5 was used to investigate the
effectiveness of using sodium sulfide
A-20
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with lime to aid in removing cadmium and
mercury. The same procedure was followed
for this sample as for Sample 3, substituting
sodium sulfide for ferric sulfate.
1.4 VAPOR COMPRESSION DISTILLATION
The purpose of this test plan was to examine the effec-
tiveness of vapor compression distillation for utility waste-
water cleanup. Sampling was done at a VCD unit in operation at
a utility site. Samples were taken for trace metals, priority
organic compounds, TDS, TSS, and TOG. Of prime concern was
the distribution of the priority pollutants present in the feed
between the product, vent, and brine streams.
1.4.1 Sampling Strategy
Grab samples of the feed, product, and waste streams
were taken. The samples were preserved in the field as indi-
cated in Table A-ll. The samples were transported to and analyzed
in the Radian Laboratory. The deaerator vent was sampled using
appropriate sampling techniques. Mercury was collected using
a gold amalgamation technique.
Organic samples from the vent were collected in a
Tenax column. The Tenax sampling was done by taking measured
gas samples in a gas-tight syringe. The gas was then purged
through the Tenax resin column where the organics were trapped
for later analysis with a gas chromatograph.
A-21
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TABLE A-ll. PRESERVATION TECHNIQUES FOR INORGANIC SAMPLES
Parameter3 Preservation Container
TDS, TSS P, G
Metals HN03, pH <2 P, G
Cyanide Cool, 4°C P, G
NaOH, pH <12
TOG Cool, 4°C P, G
H2SO^, pH <2
aTDS = total dissolved solids P = plastic, G = glass
TSS = total suspended solids
TOC = total organic carbon
Figure A-2 illustrates where the respective samples
were taken at the VCD unit.
1.4.2 Equipment
The equipment used for sampling a VCD unit is listed
in Table A-12.
TABLE A-12. VCD SAMPLING EQUIPMENT LIST
Pump Tenax columns Assorted bottles
Au amalgamation tube Gas syringe and glassware
1.5 ACTIVATED CARBON
A procedure for obtaining the data necessary to evaluate
the feasibility of removing organics from utility wastewater
streams by activated carbon is outlined. Two streams were
examined: cooling tower blowdown and ash pond effluent.
A-22
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EVAPORATOR
PRODUCT
A Grab Sample
D Au amalgamation
O Organic module
STEAM
COMPRESSOR
TO WASTE
DISPOSAL
WASTE
PUMP
PRODUCT
PUMP
RECIRCULATION
PUMP
02-5071-1
Figure A-2. Simplified system schematic of a brine concentrator.
-------
In each case, activated carbon columns were operated
on-site to simulate actual conditions for a large scale indus-
trial activated carbon unit. Each column was carefully pre-
treated to protect against trace contamination resulting from
carbon ash. In addition, each column was designed and operated
to prevent packed bed channeling.
1.5.1 Sampling Strategy
Water samples were taken from the cooling tower blow-
down and ash pond effluent. Each stream was analyzed for the
organic priority pollutants present prior to treatment. Samples
of the effluent from the carbon columns were collected and pre-
served appropriately for organic analysis. Volatile organics
were preserved in Tenax resin traps. Extractable organics were
preserved at 4°C as raw samples with methylene chloride and ex-
tracted later in the laboratory at Radian.
All samples were returned to Radian for a complete
analysis. The performance of activated carbon for removal of
organic priority organics was determined by analyzing the sam-
ples for concentrations of the compounds being investigated, as
well as TSS, TDS, and TOG. Although some heavy metals removal
has been noted in some applications, the primary emphasis on
analysis was for organics.
1.5.2 Equipment
Table A-13 is a list of the field equipment necessary
for the field testing of the activated carbon column. Carbon
preparation and column packing was done at Radian's Austin Labo-
ratories. According to an ash analysis provided by Calgon Cor-
poration, Filtra-sorb 400 has slight traces of metallic oxides
A-24
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which can be partially removed by an acid wash. Therefore,
before packing, the granular carbon was washed with a dilute
nitric acid solution and then rinsed thoroughly twice with deion-
ized water. The glass columns were also washed in this fashion.
The columns were filled with carbon to a specified height to
achieve a desired residence time. Each column was fitted with
glass wool at both ends to prevent any shift in the carbon. The
columns were transported to the field dry. In the field, deion-
ized water was pumped through each column to afford deaeration
and settling of the carbon. The carbon columns were then ready
for use in sample treatment.
A Buchler peristaltic pump was used to regulate flow
through the carbon columns. Other equipment used included
a nitrogen purge apparatus and assorted glassware (for sample
handling and preparation). Tenax resin traps (for volatile or-
ganic stabilization), methylene chloride (for liquid sample
stabilization), and ice chests (for sample storage and shipment).
TABLE A-13. ACTIVATED CARBON FIELD EQUIPMENT LIST
Calgon Filtrasorb 400 Granular Activated Carbon
Bulk Density 0.4 g/cc
Particle Density (wetted in water) 1.3-1.4 g/cc
Pore Volume 0.94 g/cc
Mean Particle Diameter 1.0 mm
Glass Column: 1.3-cm ID and 130 cm of carbon (15 min
residence time)
Buchler Peristaltic Pump (12 ml/min maximum flow)
Miscellaneous
Tenax-GC columns Methylene chloride
Nitrogen purge apparatus Ice chests
A-25
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1.5.3 Test Procedure
The following test procedure for each stream and
column was used to obtain the data necessary to evaluate the
feasibility of removing organic substances from utility waste-
water streams by carbon adsorption:
1) Before any on-site carbon testing was
started, the column was set in a vertical
operating position and loaded with de-
ionized water. The purpose of this loading
was to displace all the air in the column,
as trapped air may cause channeling or bub-
bling and give erroneous results. The
deaeration period was at least 24 hours.
This period can be shortened somewhat by
pumping deionized water through the column
and by lightly tapping the sides of the col-
umn to dislodge trapped air bubbles.
2) After the column had been purged of entrained
air, sample water from the streams to be
tested was supplied to it. A four-gallon
sample was sufficient for a six-hour
operating supply for the carbon column.
3) A flow rate of about lO.ml/min was pumped
through the column as each column was de-
signed for a surface loading of approxi-
mately 8 ml/min-cm2 (2.0 gpm/ft2).
A-26
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4) Each column required a certain period of
time to achieve stabilized operation. This
period should be no less than four times
the designed residence time for that column.
For instance, a column designed for a 15-
minute residence time will require an hour
line-out period. After the line-out period,
samples of the column effluent were collected
for organic and trace element analysis.
1.6 REVERSE OSMOSIS
<
Reverse osmosis was identified as a potential pre-
treatment technology for the removal of all priority pollutants
from utility wastewater streams. This section outlines the
procedure used for obtaining the data necessary to evaluate the
feasibility of removing heavy metals and organics from utility
wastewater streams by reverse osmosis. Two streams were examined:
cooling tower blowdown and ash pond effluent.
In each case, a portable reverse osmosis unit was
operated onsite for a specified length of time to simulate con-
tinuous operation of a large-scale industrial reverse osmosis
unit. For each stream tested, different pretreatments were re-
quired in order to prevent damage to the polyamide membrane
resulting from scaling, fouling, or chemical attack. Necessary
pretreatments were determined by onsite analysis of the stream
with a Hach DR-EL/2 Test Kit.
1.6.1 Sampling Strategy
Two three-liter samples were taken at each sampling
point for each of the utility wastewater streams tested. Grab
A-27
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samples were taken at the following points:
1) Initial intake (prior to booster pump, any
pretreatment units, and RO unit)
2) RO product (immediately after the RO unit)
Organic samples consisted of three-liter volumes which
were stabilized with 100 ml of methylene chloride and kept on
ice. In addition, three 25-ml aliquots of sample were purged
with nitrogen and volatile organics were captured in three traps
packed with a Tenax resin which preserves the chemical integrity
of each compound. These traps were desorbed for volatile organ-
ic analyses by gas chromatography at Radian's laboratory. All
organic samples were taken in specially prepared teflon-capped
bottles and kept on ice.
Three sets of 500-ml inorganic samples were taken at
each of the sample points. The stabilization technique for each
sample was determined by the subsequent laboratory analysis.
TOC samples were stabilized with sulfuric acid to a pH less than
2. Cyanide samples were preserved with sodium hydroxide to a pH
greater than 12, and trace element samples were preserved with
nitric acid to a pH less than 2. The performance of reverse
osmosis for removal of priority pollutants was determined by
analyzing all samples of concentrations of the compounds being
investigated, as well as TSS, TDS, and TOC.
1.6.2 Equipment
Table A-14 is a list of the field equipment used
for the field testing of reverse osmosis performance. The
major piece of equipment was the portable reverse osmosis (RO)
A-28
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TABLE A-14. REVERSE OSMOSIS FIELD EQUIPMENT LIST
Continental Model 3011 RO Unit (0.28 gpm; polyamide membrane)
Hach DR-EL/2 Test Kit
Continental Fouling Index Test Kit
pH Meter
Teel. Model 1P777 Rotary Gear Pump (booster pump)
Portable Power Generator
Pretreatment Units
Water softener (for calcium and magnesium removal)
Carbon filter (for free chlorine removal)
Sand filter (for suspended solids removal)
Aggregate gravel filter (for colloidal particle removal)
. Potassium permanganate filter (for iron removal)
Phosphate filter (for sodium sulfate stabilization)
Acid and chemical feed pump (for pH adjustment and/or
cationic flocculent addition)
Miscellaneous
A3200-M DuPont permeator
Teflon tubing and fittings
Tenax-GC columns
Nitrogen purge apparatus
1-gallon amber glass bottles
Methylene chloride
Ice chests
unit manufactured by Continental Water Conditioning Corporation.
The RO unit was designed to operate at 200 psi and 50% rejection,
producing a clean water stream and concentrated reject stream at
a rate of 0.28 gpm. The DuPont polyamide membrane is sensitive
to various water conditions as shown in Table A-15. This sensi-
tivity required some preliminary water analysis with the Hach
Test Kit and Continental Fouling Index Test Kit to determine
whether any pretreatment systems were necessary. The individual
A-29
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TABLE A-15. INLET SPECIFICATION FOR DUPONT POLYAMIDE MEMBRANE
pH . 4 < pH < 11
Maximum Temperature 95°F (35°C)
Jackson Turbidity Units 5 0.3
Fouling Index 5 3.0
Free Chlorine < 0.1 ppm for 4 5 pH < 8
< 0.25 ppm for 8 < pH < 11
Iron £ 3 ppm for 4 £ pH i 5.5 and
no oxygen
£ 0.5 ppm for 5.5 < pH ^ 6.5 and
1-5 ppm oxygen
< 0.05 ppm for 6.5 < pH < 11 and
1-10 ppm oxygen
Copper < 2 ppm for 4 5 pH 5 6
5 0.02 ppm for pH = 7
5 0.0002 ppm for pH = 8
pretreatment units were equipped with Eastman quick disconnect
couplings and could be easily connected in any combination to
provide proper water conditioning for the RO unit.
A small portable power generator was used for the RO
unit (110 volt, 5.8 amps, 60 Hertz, single phase AC) when no on-
site power outlets were readily available. The generator was
also used to power a booster pump which was required to draw
water from standing pools, such as the ash pond. Additional
equipment included a spare DuPont hollow fiber membrane, teflon
tubing and fittings (for necessary plumbing), Tenax-GC columns
and assorted glassware (for sample handling and preparation),
nitrogen purge apparatus (for volatile organic stabilization),
methylene chloride (for liquid sample stabilization), and ice
chests (for sample storage and shipment).
A-30
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1.6.3 Test Procedure
The following test procedure was used for obtaining
the data necessary to evaluate the feasibility of removing the
priority pollutants from utility wastewater streams by reverse
osmosis. An identical test plan was followed for synthetically
prepared samples as a part of a laboratory prefield testing
program.
1) On a sample of the stream to be tested,
the Hach Test Kit and Continental Fouling
Index Kit were used as a means of esti-
mating the pH and the amount of iron,
calcium, magnesium, copper, free chlorine,
suspended solids and dissolved solids in
the stream. These preliminary tests deter-
mined what pretreatment, if any, was necessary.
2) The pretreatment units were arranged in
the proper sequence and connected to the
RO unit.
3) A booster pump upstream of the RO unit and any
pretreatment equipment was used when the water
stream to be sampled came from a standing pool
or low pressure line (<40 psi).
4) Once the proper alignment of booster pump,
pretreatment systems and RO unit was estab-
lished, the process was ready for operation.
The booster pump was started and the RO intake
pressure gauge was checked to be certain there
was pressurized water feed to the system.
A-31
-------
5) If the RO pump pressure failed to rise above
10-15 psi, the RO unit was shut off and the
system was purged of any trapped air. Purging
was accomplished by leaving the booster pump
on and disconnecting the system inlet line im-
mediately prior to the RO unit. When a steady
stream of water flowed at the disconnected
point, the pressurized water had forced the air
from the system. If a booster pump was not in
use, the valve to the sample line was left open
and adequate water pressure (60-100 psi) was
supplied to purge the air.
6) Once the RO unit was operating, the conduc-
tivity of the initial intake and RO product
streams was checked. When the conductivity of
the RO product reached 5-10% of the initial
intake, the system was operating at typical
steady state. The RO unit continued to oper-
ate for another 30 minutes and the conduc-
tivity was checked again to ensure steady
state operation. At this time, two three-
liter samples were taken at the following
points:
a) Initial intake (prior to booster pump,
any pretreatment units, and RO unit)
b) RO product (immediately after the RO unit)
A-32
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2.0 ANALYTICAL PROCEDURE FOR ANALYSIS OF ORGANICS
There has been little investigation of trace pollutants
in wastewater streams from electric utility power plants, partic-
ularly for organics. The technical approach for organic analysis
in an investigation of wastewater streams at four representative
U.S. coal-fired utility plants is described. These wastewater
streams were sampled before and after four possible water treat-
ment technologies and then analyzed for contaminating organic and
inorganic priority pollutant species.
Based on preliminary data, organic compounds from the
priority pollutant list were identified as the organic compounds
of major concern in the Radian study. The compounds are pre-
sented in Table 3-2 of this report.
The organic analyses were conducted for both purgeable
and extractable compounds using gas chromatography (GC) and gas
chromatography-mass spectrometry (GC-MS). The procedures used
for each type of analysis were based on the analytical schemes
devised by the U.S. Environmental Protection Agency in its pro-
tocol document, Sampling and Analysis Procedures for Screening
of Industrial Effluents for Priority Pollutants (Reference Al).
To optimize results, some alterations in the instrumentation and
the laboratory procedures were made in accordance with recent in-
formation, particularly with respect to the gas chromatographic
technique.
2.1 SAMPLE COLLECTION PROCEDURE FOR GC AND GC-MS
ANALYTICAL METHODS
Preparation for sample collection and sample preser-
vation was designed to circumvent, as much as possible, certain
A-33
-------
problems considered inherent to the type of analyses which were
to be conducted. Extreme caution in the preparation of sampling
equipment and the execution of sampling technique was required.
Contamination of samples was a continual hazard due to sensitive
analytical instrumentation employed and the range of concentra-
tions for the compounds considered.
2.1.1 Bottle Preparation, Packing, and Shipment
The procedure for bottle preparation was devised, in
part, based on the U.S. EPA protocol for the measurement of toxic
substances (Reference Al). Cleaning reagents were changed to
avoid the introduction of additional organic material as pos-
sible sources of contamination.
Samples for the analysis of volatile organics were
taken in 40-ml glass vials with screw caps. These vials were
washed with a 50% solution of nitric acid and rinsed several
times with deionized water. They were baked for one hour in
a muffle furnace at 300°C. The screw-type caps were washed,
rinsed, and allowed to air dry. They were then lined with
teflon cap-liners having adhesive backing. When the baked vials
had cooled, they were tightly capped and packed.
The 1-gallon bottles used to store samples for the
analysis of extractable organic compounds were likewise washed
with a 50% solution of nitric acid and rinsed with deionized
water. These bottles were then capped with teflon-lined screw-
type caps and packed.
Cleaned, empty bottles were packed and transported in
cardboard boxes by van or trailer to the sampling site. Upon
sample collection and after preliminary sample preservation
A-34
-------
measures had been taken, three 1-gallon bottles were packed in
each insulated cooler container which was lined with fitted foam
rubber packing. Tenax resin traps of purged samples were also
placed in these coolers along with duplicate sample-containing
vials. The coolers were equipped with a sufficient number of
reusable "Blue Ice" packs to refrigerate the samples at a tem-
perature of 4°C or less, for a period of approximately two days.
The samples were maintained in this refrigerated state during
their transport by van to the Radian laboratories. Once they
had arrived, the samples were either immediately analyzed or
were kept refrigerated until the time of analysis.
2.1.2 Sampling Technique dnd Sample Preservation
The sampling procedure and means of sample preserva-
tion differed according to whether the sample was to be analyzed
for volatile organics or for extractable organic compounds. The
flow diagram presented in Figure A-3 outlines the sampling and
sample preservation procedures used for purgeable and extract-
able samples.
The points at which water samples were taken to be
analyzed for priority pollutants were from untreated water
sources and after treatment of utility wastewater streams at
coal-fired utility plants:
1) Untreated Water Sources
Plant makeup water
Cooling tower blowdown
• Ash pond effluent
A-35
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UATlilt SAMI'I.K
SOIMCIC
|
1
1 PcKSnfSLE 1 1 KXTKACTABLK 1
1 SAMPLE J 1 SAMI'I.U 1
/ill ml vial J it uulllll|e
~ '
1
1
1 1
I'urgu & triip
no ccnux res In
HUIIS|IOIt tU
Oupllcatu aiii)i|iluti Rudlnn l.uburuiury
Cool.'uTC || Maintain, '^i"C (ill to >\\
\ 1
Ti'imspiirt In
Itailian t.aliuratoiy
'l'r,ins|iort lo tixCiuct IX
Itailian Uiliiiraliuy wllli CII2C\2
1 1
(M: analysis
1 I
Uuck-ii|> iiuulytils 1 BASE/NEUTRAL L'HACT ION 1 Aijuctniii frantlon
1 1
Concent rate uxlraul
AtijutiL |>ll to <2
1 1
Excltungu C.\\;C\ ;
uolvcii t fur liuxuno
i
Concuntral o extra. -t
1
CO anil/or GC-MS
unul ya 1 a
Kx tract & uonuui\tratu
as outllnuil for U/N
1
1 ACID Ht ACT I ON 1
1
CC and /in (iC-MS
unal ya 1 u
Figure A-3. An outline of field sampling procedure and sample preservation.
-------
Feed to a vapor compression
distillation unit (VCD)
(extractables, only)
2) Treated Water Sources
Cooling tower blowdown after
treatment by reverse osmosis
Cooling tower blowdown after
treatment by activated carbon
I
Ash pond effluent after
treatment by reverse osmosis
Ash pond effluent after
treatment by activated carbon
Brine from a VCD unit
(extractables, only)
Product from a VCD unit
(extractables, only)
Volatile Organic Compounds
The Bellar purge and trap method was closely followed
for the analysis of volatile organic compounds. "On-site purg-
ing" was practiced for all samples to be analyzed by gas chro-
matography. Duplicate samples were taken and transported back
to Radian in vials for possible GC-MS analysis.
A-37
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The purgeable samples were obtained in 40-ml glass
vials with teflon-lined screw-type caps. The vial was carefully
filled from the appropriate water source without aeration or
overfilling the bottle. Additional sample was added until the
meniscus was visible above the lip of the vial. The cap was
screwed on the vial in such a way as to leave no visible bubbles
of air when the bottle was inverted. The samples were cooled to
•\-4°C until they were purged onto a Tenax resin trap or were
returned to the laboratory, still in the vial, to be purged and
analyzed there.
The purge procedure involved purging a 25-ml aliquot
of water sample, spiked with an internal standard, for 12 minutes
with zero grade nitrogen gas at a rate of 40 ml/min. Purgeable
organic compounds were evolved during the purge process and were
trapped on a resin column. The column or "trap" used in each
case was a 10-in. long, 1/16-in. ID, glass-lined stainless
steel tube. Each column was packed 2:1 with Tenax resin and
silica gel, respectively. The packing was held in place by
cleaned glass wool at both ends of the column. Newly packed
traps were baked for one hour in an oven set at 200°C and then
sealed with Swagelok caps before they were transported to the
field.
In the field, standard solutions comprised of the vola-
tile organic compounds of interest were purged with each set of
samples. After the samples and standards were collected on the
resin traps, they were refrigerated at ^4°C and maintained at
that temperature until the time of GC analysis.
The practice of on-site purging was considered to be
advantageous from a logistical as well as an accuracy standpoint.
The on-site purging method insured immediate sample preservation,
as accurate a collection of volatile organics as possible, and a
A-38
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safe and expedient means of shipment with reduced risk of sample
bottle breakage.
Extractable Organic Compounds--
The extractable samples were stored in 1-gallon
amber glass bottles containing 100-ml of methylene chloride,
"distilled in glass." Three liters of a water sample were
measured and emptied into the sample bottles. The bottle was
sealed'tightly and shaken vigorously to afford adequate mixing
of the organic and aqueous layers. All samples were then cooled
to ~4°C and maintained at that temperature until the extraction
procedure could be completed'at the Radian laboratories.
The sample extraction procedure used was a preliminary
step in the extraction and separation of organic compounds. Two
generalized extraction fractions were obtained for any given
sample:
1) Base/neutral compounds extracted first,
according to the procedural outline
2) Acidic compounds
The extractable samples were typically three liters
plus the 100-ml methylene chloride preservation additive. A
sample was first adjusted, while still in the sample bottle, to
a pH of 11 or greater with 6N sodium hydroxide. An internal
standard of hexachlorobenzene was added at this point. The gallon
bottle was resealed and shaken to suspend any sediment. The
sample was measured into a graduated cylinder and poured into
a four-liter separatory funnel. The initial volume of the methy-
lene chloride solvent was adjusted to 300 ml. The separatory
funnel was shaken for two minutes or until an emulsion was broken.
A-39
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The organic layer was then separated from the aqueous layer. Two
more solvent additions of 150 ml each were made to the aqueous
fraction and, once extracted, were combined with the first of
the organic extractions.- This combined organic fraction con-
tained ~66% of the basic and neutral components of the raw sample.
The base/neutral fraction was dried over previously extracted
and cleaned sodium sulfate and reduced to a volume of <10 ml-
The solvent was changed to hexane, and further concentration
with a micro-Snyder column was carried out to a final sample
volume of 1.0 ml. The sample was then ready for base/neutral
analysis by GC and/or GC-MS.
The aqueous layer in the separatory funnel was acidi-
fied to a pH of less than 2 with 6N hydrochloric acid.- The
extraction and concentration steps for the acid fraction were
performed in the same manner used to obtain the base/neutral
fraction.
2.1.3 Discussion
Potential sources of sample contamination, at least
in part, have been identified. Plastics of any kind which were
used in the sampling and/or analytical procedures were suspected
of contaminating samples through the leaching of plasticizer
phthalates, e.g., di-n-butylphthalate and bis(2-ethylhexyl)
phthalate. Contamination of samples also could have occurred
using glassware that retained residual amounts of cleaning
solvents on the glass surface, e.g., methylene chloride. Pre-
cautions were taken to minimize these effects.
As was mentioned earlier, the extraction procedure
followed was not a technique for the refined separation of even
classes of compounds. Rather, several classes of organic
A-40
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compounds were extracted into one fraction, e.g., the base/
neutral fraction which contained a long list of basic and neutral
compounds (including pesticides and metabolites) that were either
halogenated or non-halogenated, either aromatic or non-aromatic,
possible combinations thereof, etc. Hence, analysis of such com-
plex mixtures offered inevitable interferences since detection
of only a few compounds at very low concentration levels was
required.
Typically, these compounds that are considered priority
pollutants comprised no more than ~5% of the total organic con-
tent in any given water sample. Approximately 80-9-0-% of the re-
maining organics in natural Waters consisted of humic and fulvic
acids. Although these acid compounds are bulky, complex, and
largely ionic molecules which do not lend themselves well to an
extraction technique, they are in any case partially extracted.
Both humic and fulvic acids were expected to present some degree
of interference to a sensitive analytical technique such as gas
chromatography.
Sources of contaminating interferences were related
to the extraction procedure itself. All extraction fractions
were filtered to remove residual moisture before they were
concentrated. Schleicher and Schuell analytical filter papers
were used for this purpose. An investigation of the extraction
procedure revealed that contamination of sample solutions re-
sulted from these filter papers. Specifically, di-n-butyl-
phthalate was identified as a contaminant from these papers.
Possibly, there were other contaminating phthalates from this
source as well.
In some instances, sample fractions were filtered
twice. When sample fractions could not be concentrated on the
same day that they were extracted, they were first filtered and
A-41
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then refrigerated. Condensate formed in the bottles during the
period of refrigeration so the samples were refiltered to remove
the additional moisture before the concentration procedure was
initiated. Double filtering afforded more contamination poten-
tial than otherwise would have been expected.
2.2 METHODS OF ANALYSIS FOR ORGANIC COMPOUNDS
The technique of gas chromatography-mass spectrometry
(GC-MS) was used as a back-up method to GC analysis for the posi-
tive identification of compounds comprising the raw inlet samples
Mass spectral analysis, according to the procedure outlined in
the EPA Protocol (Reference Al), provided for comprehensive com-
puter searches of samples for the programmed detection of any
compound specified by the Consent Decree List of compounds.
The 129 "unambiguous priority organic pollutants"
associated with the Consent Decree are categorized into two
groups, dependent on the type of sample preparation required
for their analysis:
1) Purgeables - those organic compounds
that are amenable to the purge and
trap method and subsequent analysis
by gas chromatography
2) Extractables - those organic compounds
that are solvent extractable and amen-
able to gas chromatography
2.2.1 Organic Analysis by Gas Chromatography
Analysis of priority pollutants by gas chromatography
can be applied to concentrations in the parts per billion range.
A-42
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Only recently has there been concern for the presence of organics
at these levels of concentration. Consequently, very few stan-
dards for regulation of organic concentration levels in water,
natural or otherwise, have been officiated by the Government.
Interim standards, such as exist now, have been applied to a few
organic pesticides. These compounds are listed in Table A-16
(Reference A2).
Gas chromatography was used more extensively than GC-
MS in the analysis of organics in water samples. Utility plant
makeup water samples and all untreated and treated utility waste-
water samples examined were analyzed by GC and its associated
detector unit.
TABLE A-16. MAXIMUM CONTAMINANT LEVELS FOR ORGANIC CHEMICALS a
Level, milligrams
Contaminant per liter
A. Chlorinated Hydrocarbons
Endrin (1,2,3,4,10, 10-hexachloro-6, 7-epoxy-l,4,
4a, 5,6,7-, 8, 8a-oct ahydro-1,4, -endo, endo-5,
8-dimethanonaphthalene). 0.0002
Lindane (1,2,3,4,5,6-hexachlorocyclohexane,
gamma isomer). 0.004
Methoxychlor (l,l,l-trichloro-2,2-bis[p-methoxy-
phenyl] ethane). 0.1
B. Chlorophenoxyls;
2,4-D, (2,4-dichlorophenoxyacetic acid). 0.1
2,4,5-TP Silvex (2,4,5-trichlorophenoxypropionic
acid). 0.01
aSource: Reference A2
A-43
-------
Analysis was based on detection of any compounds re-
ported as having been identified in trace amounts in some utility
wastewaters or compounds commonly found in water samples. Table
A-17 presents a list of these compounds organized according to
the procedure and method of analysis, i.e., whether compounds are
purgeable or extractable from water samples and whether their
measurement employed a Hall or Flame lonization Detector.
TABLE A-17. ORGANIC COMPOUNDS IDENTIFIED FOR GC ANALYSIS
PURGEABLES - HALL DETECTOR
Bromodichloromethane
Bromoform
Chloroform
Chloromethane
Dib romochlo rome thane
1,2-dichloroethane
Tetrachloroethylene
1,1,1-trichloroethane
Trichloroethylene
Trichlorofluoromethane
PURGEABLES - FLAME IONIZATION
DETECTOR
Benzene
Ethylbenzene
Toluene
BASE/NEUTRAL EXTRACTABLES -
HALL DETECTOR
Aldrin
y-benzene hexachloride (or)
6-benzene hexachloride
2-chloronaphthalene
4-chlorophenyl ether
ODD (or) B-endosulfan
DDT
1,3-dichlorobenzene
1,4-dichlorobenzene
Dieldrin (or) DDE
o-endosulfan
Endosulfan sulfate (or)
Endrin aldehyde
Endrin
Heptachlor (or) 6-benzene
hexachloride
BASE/NEUTRAL EXTRACTABLES -
HALL DETECTOR (Cont'd)
Heptachlor epoxide
Hexachloroethane (or)"1,2-dichlorobenzene
Hexachlorocyclopentadiene
Methoxychlor
1,2,4-Trichlorobenzene (or) Hexa-
chlorobutadiene
BASE/NEUTRAL EXTRACTABLES -
FLAME IONIZATION DETECTOR
Acenaphthene
Acenaphthylene
1,2-benzanthracene (or) Chrysene (or)
Bis(2-ethylhexyl) phthalate
3,4-benzofluoranthene (or) 11,12-
benzofluoranthene
Butylbenzylphthalate
Diethylphthalate
DimethyIphthalate
Di-n-butylphthalate
Fluorene
Fluoranthene
Indeno (1,2;C,D) pyrene
Naphthalene
Phenanthrene (or) Anthracene
Pyrene
ACID EXTRACTABLES - HALL DETECTOR
Pentachlorophenol
ACID EXTRACTABLES
- FLAME IONIZATION
DETECTOR
Phenol
A-44
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2-2.1.1 Instrumental: ion--
Water samples were analyzed using a Tracor'560 Dual
Detector Gas Chromatograph equipped with the Flame lonization
Detector and the Tracor 700 Hall Electrolytic Conductivity De-
tector. The Radian-designed field purge unit (FPU) and desorp-
tion apparatus were employed for the volatile organic analysis
(VGA) procedure. A Hewlett-Packard 3380A Data Integrator Record-
er documented a visual display of the chromatographic data for
every sample fun and reported the GC retention time and in-
tegrated area of each recorded peak on the chromatogram.
2.2.1.1.1 Hall Electrolytic' Conductivity Detector--The working
concept of the Hall Electrolytic Conductivity Detector in GC
Analysis is the selective detection of halogenated, nitrogenated,
or sulfonated trace organic compounds. Such compounds that are
contained in a sample solution are injected into a GC analytical
column. As the compounds elute through the column in character-
istic order and retention time, the column effluent is intro-
duced into a high temperature pyrolyzer furnace consisting of a
quartz reaction tube constantly fed by a reaction stream of hydro-
gen gas. The pyrolyzer converts specific elements in the organic
compounds to soluble electrolytes. The electrolytes are combined
with a stream of deionized liquid (ethanol) in a gas-liquid con-
tactor. Those gaseous components, readily soluble and ionized in
the liquid, are detected and measured by continuous monitoring
of the electrical conductivity of the liquid via an AC bridge
circuit and auxiliary integrator-recorder.
A-45
-------
2.2.1.1.2 Flame lonization Detector—The Flame lonization Detec-
tor (FID) is considered to be a universal detector. However,
there are a number of gases which give little or no signal
when analyzed by the FID. Some of these compounds are therefore
useful as solvents.
As with the Hall Detector, a sample is injected into
a GC column and is eluted through the column. The organic com-
pounds in the column effluent are burned by an oxidative hydro-
gen flame (fed with excess oxygen) to produce ionized molecular
fragments. These ions are collected by means of an electrical
field on a collector electrode. The individual compound response
is monitored via an AC bridge circuit and auxiliary integrator-
recorder.
2.2.1.1.3 Field Purge Unit (FPU)--An apparatus was devised at
Radian Corporation that provided a simple and efficient means of
purging VGA samples in the field. The Radian-designed portable
FPU was used every time a VOA sample was to be purged whether it
was under field conditions or at Radian Laboratories. The unit
capacity for purging two samples simultaneously expedited the
task of effecting sample preservation immediately following
sample collection.
A minimal amount of equipment and space was needed for
on-site purging of samples. Aside from the FPU itself, which
contained all of_the tubing and fittings required, there was an
aspirator device equipped with vacuum pump. The aspirator was
used for cleaning needles, syringes, and glassware. The needles
and syringes were employed as a means of delivering samples and
standards to the sample purge tubes. Extra purge tubes and other
A-46
-------
laboratory glassware were stocked in case of breakage. One tank
of zero-grade nitrogen gas, used for purging samples on-site,
sufficed for the entire sampling effort.
The portable purge unit was photographed in operation
on-site and is shown in Figure A-4.
2.2.1.1.4 Desorption Device—An apparatus was constructed to be
placed immediately over the in-port valve of the GC instrument
for direct desorption of volatile compounds from the Tenax trap
into the GC analytical column.
(
The desorption apparatus consisted of a cylindrically-
shaped heating mantle attached to the vertical support by adjust-
able clamps. The inport valve to the GC column was modified
in the case of the VGA to accommodate direct attachment of a
VOA Tenax trap as its contents were analyzed. The mantle could
be moved vertically such that it could be lowered to surround
the Tenax trap, providing a heat-box effect. The mantle was
then raised again for cooling and removal of the used trap. In
the desorption mode, the Tenax trap was heated to 180-200°C and
flushed with the nitrogen carrier gas. In this way, the desorb-
ed volatile organics were loaded onto the front end of the GC
analytical column and ready to be analyzed.
2.2.1.2 Instrument Operating Parameters--
Each of the sample fractions (1. purgeables; 2. base/
neutral extractables; and 3. acid extractables) was analyzed
by both the Hall and the F.I. detectors. The operating para-
meters of the GC and associated detectors varied depending on
the type of sample fraction to be analyzed.
A-47
-------
NITROGEN GAS I ROTOMETERS V TENAX TRAPS
GAS-LINE
FILTER
SAMPLE
PURGE
TUBES
ASPIRATOR
APPARATUS
Figure A-4. Field purge unit (FPU).
A-48
-------
2.2.1.2.1 Purgeables--The same procedure for "purge and trap"
was used for all purgeables analyzed by either detector. There
were some variations, however, with respect to certain operating
parameters of the analytical instrument assembly.
Hall Detector - The Tenax traps were heated
rapidly to 180-200°C and back-flushed with
zero-grade nitrogen gas at a flow rate of
"55 cm3/min. The GC analytical column for the
VOA procedure was a 6- mm OD , and 2 -mm ID,
nine-foot long coiled glass column. The first
foot of the column was packed with 80/100 mesh
Chromosorb coated with 37, Carbowax 1500 . The
remaining eight feet of the column were packed with
60/80 mesh Carbopac C coated with 0.27, Carbowax
1500. The GC oven was programmed for an initial
temperature of 40° C. This temperature was held
during the four -minute trap desorption period. At
the end of this period, the oven was heated
rapidly to 60 °C and held at that temperature
for four minutes. At this time, the oven was
heated 8°C/min until it reached 170 °C. The
final temperature was held for 4-12 minutes
to insure that all compounds had been eluted.
The flow rate of the nitrogen carrier gas was
-55 cmVmin. The flow rate of the zero-grade
hydrogen reaction gas was ^45 cm
F.I. Detector - The Tenax traps were heated
rapidly to 180-200 °C and back-flushed with
zero-grade nitrogen gas at a rate of 30 cm3/min.
A-49
-------
The GC analytical column used was the same as
that used -for the Hall Detector. The GC oven
temperature program was the same as for the
Hall Detector. The final temperature, however,
was held for 10-15 minutes. The flow rate for
the nitrogen carrier gas and for the hydrogen
reaction gas was 30 cm3/min. The flow rate for
the zero-grade air was set at ^0.8 scfh @ STP.
2.2.1.2.2 Base/Neutral Extractables—The base/neutral (B/N) com-
pounds were extracted in the first fraction obtained in the
extraction procedure. Compounds classified as metabolites and
pesticides were also extracted in this fraction. After the
extracted fraction was concentrated according to procedure, it
was ready for injection into the GC column and analysis.
Hall Detector - All of the B/N compounds were
analyzed using a 6-mm OD, and 2-mm ID, six-foot
long coiled glass column. The column was packed
with six feet of 100/120 mesh Supelcoport coated
with 170 SP-2250. The GC oven was programmed
for an initial temperature of 50°C to be held
four minutes. After four minutes, the temperature
increased at a rate of 8°C/min until 260°C was
reached. This final temperature was held 5-15
minutes. The carrier gas flow rate was ~55 cm3/niin.
The hydrogen gas flow rate was set at ~45 cm3/min.
F.I. Detector - The GC analysis parameters for
the analytical column and the oven temperature
program were the same as for the Hall detector.
A-50
-------
However, the flow rates were somewhat altered for
the carrier gas and the hydrogen gas, being ^50
cm3/min and -^30 cm3/min, respectively. The flow
rate for the dry air was set at ^0.8 scfh @ STP.
2.2.1.2.3 Acid Extractables--The acid extractables were obtained
in the second fraction of the extraction procedure. One com-
pound from this fraction was given particular regard and this
was phenol. Although phenol was analyzed by FID, the acid
fraction was also analyzed by the Hall Detector perchance some
concentrated priority pollutant would be detectable.
Hall Detector - The GC column used to analyze
the acid extractable compounds was the six-foot
coiled glass column packed with six feet of 60/80
mesh Tenax GC. The GC oven temperature was pro-
grammed initially for 130°C (at the tine of
injection) and to progress at a rate of
8°C/min until 300°C was reached. This
final temperature was held 10-15 minutes.
The flow rates for the nitrogen carrier
gas and the hydrogen reaction gas were
-55 cmVmin and -45 cm3/min, respectively.
F.I. Detector - The Tenax GC analytical
column was also used for the F.I. detec-
tion of acids. The Acid-Hall Detector
program for the temperature regulation
of the GC 'oven was used for F.I. analysis.
The flow rates of the nitrogen carrier gas
A-51
-------
and hydrogen reaction gas were ^50 cm3/min
and ^30 cm'3/min, respectively. The dry air
flow rate was set at ^0.8 scfh @ STP-
2.2.1.3 Sample Analysis and Data Interpretation--
Identification and quantification by GC analysis of
organic compounds in the three sample fractions (1. purgeables;
2. base/neutral extractables; and 3. acid extractables) were
based on the percent recovery and relative retention time of
internal standards (IS), i.e., measured aliquots of standard
solutions of organic compounds used to spike the sample solutions,
The internal standards used for the GC analysis were:
1) Purgeables - Hall Detector
1,4-dichlorobutane (IS)
Bromochloromethane (IS)
2) Purgeables - F.I. Detector
Cyclohexane (IS)
3) Extractables - Both Hall and
F.I. Detectors
Hexachlorobenzene (IS)
If an internal standard for some reason was not ade-
quately recovered, straight retention times based on GC analysis
of external standards were used to identify compounds. In such
cases, quantification was calculated according to the percent
recovery of an external standard which was analyzed on the same
day as the samples being quantified. The external standards were
those listed in Table A-16.
A-52
-------
External standards were analyzed daily, with every
4-6 samples analyzed on one detector. This was done to insure
sufficient monitoring of possible variation in the sensitivity
of response and/or any other operating condition of the GC
detector-recorder instrument assembly. Operating conditions
as reflected by these standard runs provided the major source
of information for understanding and interpreting the sample
data.
Standard solutions were made up in concentrations com-
mensurate with the concentration levels anticipated in sample
solutions. For example, standards used in defining detection
limit parameters were generally 4 ppb in concentration. In
determining the detection limits, GC analyses of monitor-type
standards were reviewed, taking into consideration ranges of
percent recovery and relative retention times (RUT) and the
background noise attributed to electrical noise and solution
matrix. Realizing that sensitivity to GC analysis varied among
the compounds being analyzed, standards for each compound
were reviewed. A worst case response per compound was noted
and a conservative detection limit was assigned in light of
all identifiable interferences.
The variance in percent recovery was calculated from
the high and low data points for each standard. Based on these
figures, error limit approximations were calculated for all
sample fractions analyzed by either detector unit:
1) Purgeable's - Hall Detector
Detection Limit: 4 ppb, Trichloroethylene
2 ppb, Tetrachloroethylene
1 ppb, all others
Error Limit: ±30%, all compounds
A-53
-------
2) Purgeables - F.I. Detector
Detection Limit: 1 ppb, all compounds
Error Limit: 5070) Benzene
207o, Toluene and Ethylbenzene
3) Base/Neutral Extractables - Hall Detector
Detection Limit: 1 ppb, all compounds
Error Limit: ±50%, all compounds
4) Base/Neutral Extractables - F.I. Detector
Detection Limit: 1 ppb, all compounds
Error Limit: ±50%, all compounds
5) Acid Extractables - Hall Detector
Detection Limit: 1 ppb, all compounds
Error Limit: ±5070, all compounds
6) Acid Extractables - F.I. Detector
Detection Limit: 1 ppb, all compounds
Error Limit: ±20%, all compounds
On several occasions, one or more peaks, discernible
on a sample chromatogram, were not identifiable by the usual
standards. In this event, a standard containing the full list
of Consent Decree compounds corresponding to a given sample
fraction (e.g., purgeables - Hall Detector) was analyzed for
purposes of comparison (refer to Table A-18). If no identifica-
tion could be made, the peaks were reported as "unidentifiable"
and considered to be not representative of any priority pollu-
tant as upheld by the Consent Decree.
In an effort to define a line of discrimination be-
tween spurious and 'discernible1 peaks, three categories, A,
A-54
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TABLE A-18.
EPA CONSENT DECREE LIST OF "UNAMBIGUOUS
PRIORITY POLLUTANT" ORGANIC COMPOUNDS
ExtrvctJbL* Coavounda
Sua/Haucrala
?ucleid« 4 Macibollcu
ErnodlcaloroaMcbaoa
Oib mKBloroBacbaaa
TacrachlorMchylaaa
Carbon cacraehJLorlda
Cblorobcniau
1« 2~dlchlorMcnaaa
l.l.l-crlchloroachaaa
1.1.2-crlchlonachau
1.1.2,2-cacracaloroacbaaa
Chlorocchaaa
1,1-dlcbloreachy Una
L . 2-dlchloropropana
1.J-JichloropropyUna
(cla and crana)
Micli7l
-------
B, and C, were described by which all of the possible peaks
could be evaluated. To Category A were ascribed all spurious-
type peaks which measured less than 2-3 times the height of the
background noise. These were considered to be part of the back-
ground. Category B consisted of peaks which were definitely
'discernible' and which measured 4-5 times the height of the
background noise. These peaks were equal to or greater than the
detection limit for a given compound and were considered quanti-
fiable. Category C consisted of peaks larger than those of Cate-
gory A, yet measuring less than the detection limit, as defined.
These peaks were considered 'discernible1 and, if correspondent
to identifying RRT's, were identified and reported as present
in less than detection limit concentrations.
The occurrence of peaks considered either spurious or
unidentifiable was principally attributed to the presence of
other organics in -the sample solutions. As stated earlier, the
priority organics listed by the Consent Decree represent a very
small percentage of the total organics in a water sample (refer
to Section 2.3). The presence of other organics offered frequent
interferences with the analysis of samples and with the interpre-
tation of the data. Extraneous organics which were either inher-
ent to a sample matrix or were the result of contamination may
have:
1) Covered up or camouflaged other peaks
which perhaps represented valid data
2) Prevented clean separation of peaks,
hence, unresolvable peaks
3) Appeared at RRT's coincident to compounds
of interest thereby causing false identi-
fication of compounds
A-56
-------
4) Caused a large instrumental response
interfering with normal base-line
attenuation and obscuring the presence
of pertinent compounds
For a sample solution, the content of which is totally
unknown, to be characterized by GC analysis, a back-up monitor
by GC-MS instrumentation is required. The need for this prac-
tice is made apparent in the above discussion. However, it can
be said of a sample solution, analyzed by GC for compounds of
known sensitivity to this method of analysis, that if analysis
shows no 'discernible' peaks
-------
DU.
: s
j. 56 Bromochloromechane (IS)
.- •:• * 54-
Bromodichloronechane
*> -* Trichloroechylerie
<=.TI Dibromochloromechane
Iy 12 L,i.-dichlorofaucane (IS)
'STO
AREA %
RT
2.45
3.63
4.85
5.83
6.98
7.88
11.28
13.77
14.73
18.18
20.33
TYPE
M
M
AREA
1352839
381583
96498
5881
257407
12108
164244
15249
18495
4442
237432
HP 3330A
DLY OFF
MV/M 3.0J?
STOP
ATTN
53.13
14.99
3.79
.281
10.11
.475
6.451
.598 8
.726 4
.174 5
9.325
REJECT 1000
32
Figure A-5. Example chromatogram of a typical GC sample analysis
A-58
-------
2.2.2.1 Ins trumen tat ion—
The water samples were analyzed utilizing a Hewlett-
Packard 5982A combined Gas Chromatograph-Mass Spectrometer
(GC-MS). A Hewlett-Packard 5834A Data System was used for the
collection, storage and retrieval of data.
The GC-MS instrument consists of a Hewlett-Packard
5710A gas chromatograph and a Hewlett-Packard 5982A dodecapole
mass spectrometer and GC-MS interfaces. The instrument is equip-
ped with a dual ion source for operation in the electron impact
or chemical ionization mode. The major features of the system
include: 3-1,000 amu mass range covered in a single scale; ad-
justable scan rate of 325 amu/sec; sensitivity to picogram levels,
even with large samples; provision for membrane and jet separa-
tors; analog to digital measurements at every 0.1 amu; and
resolution permitting full separation of half masses.
The Hewlett-Packard 5933A data system controls the
scan functions of the Hewlett-Packard mass spectrometer, and
stores the acquired mass spectral data on magnetic discs. In
addition, the Hewlett-Packard 5933A data system will search and
compare acquired mass spectra against four disc-stored mass
spectral libraries containing over 15,000 mass spectra. Radian
also has the capability to access and search the data banks
available from the Cyphernetics Corporation.
GC-MS system performance evaluation was conducted each
day the system was used for these analyses, as it is for all
samples analyzed by GC-MS at Radian. The computerized system
was tuned and checked using decafluorotriphenylphosphine accord-
ing to the recommended EPA procedure.
A-59
-------
2.2.2.2 Sample Analysis and Data Interpretation--
Each of the sample fractions (1. purgeables, 2. base/
neutral extractables, and 3. acid extractables) required a sepa-
rate GC column for best resolution of the desired components.
It was therefore necessary that three separate GC-MS runs be
completed for each sample.
Three standard solutions were prepared to correspond
with the three classes of organics being analyzed. These
contained:
1) Purgeables in methanol solvent
2) Acid extractables in methylene chloride
3) Remaining compounds on the Consent Decree List
also in methylene chloride solvent
These solutions were used to quantify the compounds found in
the samples.
A typical qualitative analysis of a given sample was
achieved by injection of a measured quantity of the material into
the appropriate gas chromatographic column. Temperature program-
ming was specific to the type of compounds being analyzed
(purgeable or either extractable group) and the GC column being
used. This was designed to maximize resolution of the organic
compounds. As the organic species were eluted from the column,
they were transferred to the ion source of the mass spectrometer
through a membrane separator. The mass spectrometer was scanned
continuously from a mass to charge (m/e) ratio of 50 to 450 with
a cycle time of approximately 3 seconds. Electron impact (70eV)
A-60
-------
mass spectrometry was employed exclusively for the analyses. The
mass spectra obtained were stored on a magnetic disc for future
evaluation.
Qualitative identification of the compounds of interest
was based on the appearance of key ions at specified m/e values
and the correspondence with known gas chromatographic retention
times for standards. In addition, each compound was positively
identified only if the ratio of the intensities of the key ions
for each peak corresponded to the intensity ratios for the
standard mass spectra.
/
Quantitative analysis of the identified compounds was
achieved through the selected ion monitoring (SIM) technique
using the computerized mass spectral data. When resolution of
the components of interest was not complete, selected ion frag-
ments were chosen that were characteristic of the compound to
be quantified. More than one ion fragment was selected in each
case in order to maintain quality assurance and confidence that
no significant ion counts were contributed by interfering peaks.
Ratios of the ion counts of these fragments in the sample were
compared to the same ratios in the standard.
For each compound, the area under the most abundant
key ion was calculated using the data system. This computed
area was compared to the areas found from analyzing standard
mixtures, and the concentration of each compound in the sample
was then determined by reference to a calibration curve.
Figure A-6 is a computer printout sheet depicting the
GC-MS analysis for volatile organics in a utility wastewater
stream. In this water sample, four halogenated volatiles were
A-61
-------
11 in
Tl
H«
OQ
hh O
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1 0
T)
*S ^
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H n>
OQ i-1
(D H-
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M P4
(0
TO 0
PJ rt
a o
H. pi
o rt
0)
O
P co
CO CO
rt
(D co
STJ
to (D
rt O
fD rt
w M
(U
i co
T3 (D
fO
O
tr
n
1/7
HIM irifTU II I I I II II 1 II M nui TM1TTTrTTrTTTTTTrTTtTTTrTTTITT'f7TT11TrTTTrrTTTTTTI"riin I'llriTTTTTTI I I'fTIITTTT
:>u inu \'i" tun run iiiii ihii inn oii :>iin :i:m unn IIMI 71111 /:,(. nun iriii mm 'J'.iii H.IIII iir.ii IIMI 11
" ' l'iriflif'yi'ri'tifl'i'»'f'flHi 11
',|-| I I Ml Hill I Ml i'llll i"JII 'Jllll KiH 4IIII 4!ill Mill S^ll hllll h:.ll "Jllll '/:.() Illlll IIMI 9IIII USD Hlflll I IIMI I IIIII
-------
positively identified. The top line of the printout is a GC
chromatogram representing total ion compositions (TI) of the
compounds present. Each of the four lower lines represents a
selected key ion fragment (Nos. 83, 129, 127, 173). Each of
these key ions is characteristic of one or more compound. A
combination of two or three (or more) key ions is usually a
positive identifying feature of a given compound. The com-
pounds identified in this sample were:
1) Chloroform - an identifying key ion 83
corresponds to the peak on the total ion
line at 5.0 minutes GC-retention time
2) Bromodichloromethane - identifying key
ions 83, 129 and 127 correspond to the
peak on the total ion line at 8.2 minutes
GC-retention time
3) Dibromochloromethane - identifying key
ions 129 and 127 correspond to the peak
on the total ion line at 11.0 minutes
GC-retention time
4) Bromoform - an identifying key ion 173
corresponds to the peak on the total ion
line at 13.5 minutes
Figure A-7- is a computer print-out of the mass spec-
trum at point 339 at 11.0 minutes GC-retention time, correspond-
ing to the compound dibromochloromethane of the preceding
sample. In this mass spectrum or identifying "fingerprint" for
dibromochloromethane, the key ion fragments are expressed in
proportionate sizes indicating quantity ratios. Quantities are
A-63
-------
>
.p-
FRN 10724 SPECTRUP1 339 RETENTION TIME 11.0
LHRO.ST 4« ias.8,100.0 126.8, 76.9 130.8, es.i 73.9, 15.1
LrtST 4i 269.9, .3 275.7, .3 290.5, .2 299.5, .3
PAGE 1 V • 1.00
100
80
60
ao
0
100
80
60
40
20
0
1 1 1
20 40 60 80 100 120
Hi! • IL! j Li -.1.! 1
III lllllllll 1111)1111 llll)
140 160
'
'111 I ,
180 200 220 240 260 880 300 320
Figure A-7. Computerized printout of mass spectrum at Point 339
for dibromochloromethane.
-------
normalized such that the most abundant ion fragment arbitrarily
equals 10070. Sample ratios must agree with the ratios estab-
lished for standards of a compound before identification can
be confirmed.
Since the GC-MS system is completely computerized,
the mass spectral data of other compounds not on the Consent
Decree List, but which are possible significant pollutants, can
be stored to be examined at a later time.
A-65
-------
3.0 ANALYTICAL PROCEDURE FOR ANALYSIS OF INORGANICS
3.1 INTRODUCTION
This section describes the inorganic sampling and
analytical strategy for the assessment of wastewater treatment
technologies as applied to the utility industry.
Samples were collected from three water streams within
each of the plants. These streams included:
1) Cooling tower blowdown (CTB)
2) Ash pond effluent (APE)
3) Plant inlet water
Bench-scale operations of the three technologies assessed
(carbon adsorption, reverse osmosis, and chemical precipitation)
were applied to the two effluent streams. Plant inlet water was
collected to define the quantity of priority pollutants entering
the plant.
Grab samples were also collected around an operational
full-scale vapor compression distillation unit at one plant.
Samples collected included the feed, product, and reject brine.
The following trace elements and water quality para-
meters were chosen for an analytical laboratory investigation
of resulting water samples:
Trace elements
arsenic nickel
antimony selenium
beryllium silver
A-66
-------
cadmium thallium
chromium vanadium
copper zinc
cyanide Total Organic Carbon
lead Total Suspended Solids
mercury Total Dissolved Solids
The parameters measured were from the EPA list of pri-
ority pollutants of industrial effluents. Figure A-8 presents
the analytical scheme used for inorganic compounds. The analyti-
cal scheme consists of the type of analyses to be performed on
the sampled raw water streams and the treated water streams.
Complete characterization of each sample for all parameters was
not necessary. The focus of the activated carbon treatment
study centered on organic adsorption. The total organic con-
tent was monitored by measurement of total organic carbon.
Chemical precipitation samples were evaluated for trace element
removal. Both raw and filtered effluent streams were analyzed
to determine trace element content in the suspended solids.
3.2 SAMPLING
Reverse osmosis (RO) samples were collected directly
from the RO unit during.on-site operation. Initially sampling
was monitored using a conductivity meter. Carbon column samples
were taken from the column following a line-out time of approxi-
mately 1 hour.
Chemical precipitation samples were collected follow-
ing the jar test procedure performed on-site. The pH of the raw
sample was adjusted to the appropriate pH with a lime slurry.
Additional coagulants were also added at this time. Following
a period of flocculation and settling, the samples were filtered
through a 10-micron gravity filter.
A-67
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Plane Inlec
Water ~
TM. CN, TOG
Gaoling Tower
Slowdown
Ash Pond
Effluent
TM, TOG
TOG
TM. TOG
TM, TOG
'Chemical
ppt *
Tff-*H **
5.0 —
-------
All raw, filtered, and treated (reverse osmosis,
carbon adsorption, and chemical precipitation) samples were
preserved immediately after collection according to the analysis
to be performed. Table A-19 presents the preservative used for
the different types of analysis.
TABLE A-19. PRESERVATIVES FOR ANALYSES
Analysis Preservative pH
Trace metals HN03, redistilled <2.0
Cyanide NaOH, pellets >12.0
TOG HaSOi, 2.0
TDS, TSS No preservation
Following colletion and preservation, the samples were stored in
polyethylene bottles and transported to the Radian laboratory.
During transportation, the temperature of the samples was main-
tained below 5°C.
3.3 ANALYTICAL METHODS
All trace metal analyses, except selenium, were per-
formed by atomic absorption (AA). Selenium was analyzed by
fluorometry following an organic extraction procedure. Cyanide
was analyzed by colorimetric procedure. Total organic carbon
was analyzed using a non-dispersive infrared spectrophotometer.
A standard jar test apparatus was used for the settling data.
The instruments used for analysis were:
1) Instrumentation Laboratories Model 351 AA with
CTF 555 Flameless Atomizer
2) Perkin-Elmer Model 503 AA Flameless Atomizer
A-69
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3) Turner Fluorimeter Model 111
4) Coleman Model 124 Double-beam UV-Visible
Spectrophotometer
5) Oceanography International Carbon Analyzer
6) Hach Model 15057 Floe Tester
3.3.1 Digestion Methods
Trace metal samples were digested according to EPA
protocol. Sample preparation followed the methods described
below.
Method A--
A 100-ml aliquot of the sample was transferred to a
Pyrex beaker. Five milliliters of 6N hydrochloric acid were
added, and the sample was then heated for one hour at 95°C.
Following cooling, the sample was diluted volumetrically to
100 ml.
Method B--
A 100-ml aliquot of the sample was transferred to a
Pyrex beaker. Three milliliters of 15N redistilled nitric acid
and 5 ml of 30% hyrdogen peroxide were added. The sample was
heated at 95° C until the volume was reduced to less than 50 ml.
After cooling, the volume was adjusted to 50 ml.
The analytical methods for analysis of each element
using these digestion techniques are indicated in Table A-20.
A-70
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TABLE A-20. ANALYTICAL METHODS FOR DETECTION OF METALS
Method A Method
B
Flame Flameless Flameless
Be Be As b
Cd Sb Cd
Cr Cr
Cu Cu
Ni Ni
Pb Pb
Zn Zn
Ag
Tl
alf the concentration was near the detection limit for flame AA
analysis, reanalysis by ftameless AA (graphite furnace) was
performed.
Matrix modifications technique.
3.3.2 Trace Metals Analysis
Analysis by standard AA flame techniques was first
attempted (Table A-20). If the analytical concentration was
below reliable detection limits, the sample was injected into
the flameless graphite atomizer attachment of the AA. All flame-
less analyses were performed on the designated digestion (Table
A-20) by direct injection. No preconcentration procedures were
used. Arsenic, due to its volatility, was pretreated by adding
ammonium molybdate to an acidic aliquot of the samples. This
matrix modification technique, producing a more thermally stable
arsenic compound, allowed higher charring temperatures for matrix
removal.
A-71
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Table A-21 lists the analytical wavelength used for
each element and the atomization program used in the flameless
technique.
TABLE A-21.
ANALYTICAL WAVELENGTHS IN ATOMIZATION
PROGRAM FOR ELEMENTS ANALYZED
Element
Ag
As
Be
Cd
Cr
Cu
Hi
Pb
Sb
Tl
V
Zn
Wavelength , run
328.1
193.7
234.9
228.8
357.9
324.7
232.0
283.3
217.6
276.8
318.4
213.9
Dry, °C
100
100
100
100
100
100
100
100
100
100
100
100
Pyrolize, °C
300
1000
1000
400
900
750
600
600
400
400
750
425
Atomize, °C
1800
2000
2500
2000
1850
1800
1950
1900
2250
1800
2800
1500
Mercury--
Mercury was determined using a cold vapor technique with
the AA. A 100-ml aliquot of the undigested sample was transferred
to a BOD bottle. The mercury was oxidized to Hg * in acidic con-
ditions with excess potassium permanganate. Excess permanganate
was removed with hydroxlamine. Stannous chloride was then added
to reduce Hg 2 to elemental mercury. The mercury vapor was swept
through the absorption cell of the AA. The determination was made
at a wavelength of 253.6 nm and compared to standards prepared in
the same fashion.
A-72
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Seleni-um--
The fluorimetric determination of selenium was accom-
plished by heating a 5-ml aliquot of the undigested sample with
dilute HC1. Selenate was reduced to selenite by this procedure.
Interferences were masked by the addition of hydroxylamine, EDTA,
and formic acid. A fluorescent, photo-sensitive piazselenol was
formed by the reaction of the selenite with 2,3-diaminonaphthalene
The complex was extracted into cyclohexane. The organic complex
was excited at 369 nm and the resulting fluorescence measured at
522 nm. Concentration was determined by comparison to standard
selenium solutions carried through this procedure.
3.3.3 Cyanide and TQC Analysis
Cyanide and total organic carbon were determined by
standard techniques. Cyanide was analyzed by colorimetry using
a Coleman Model 124 double-beam Spectrophotometer. Total organ-
ic carbon was analyzed by a non-dispersive infrared technique
using an Oceanography International Carbon Analyzer. Each anal-
ysis was performed on specifically preserved samples.
Cyanide--
Cyanide analysis was performed on the sample preserved
with sodium hydroxide. A 250 ml aliquot of the sample was trans-
ferred to the reaction flask of the cyanide distillation appara-
tus, Figure A-9. The sample was acidified with 50 ml of 9N sul-
furic acid and 20 ml of 2.5N magnesium chloride. The hydrogen
cyanide gas was distilled from the flask into 100 ml of 1.25N
sodium hydroxide in a gas washing bottle. Following a reflux
time of one hour, the absorbing solution was diluted to 200 ml.
A 20-ml aliquot of this solution was transferred to a 50-ml
volumetric flask. The aliquot solution was buffered with 15 ml
A-73
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ALL1HN CONDENSER
AIR INLET TUBE
ONE LITER -
BOILING FLASK
HEATER
CONNECTING TUBING
SUCTION
GAS ABSORBER
Figure A-9. Cyanide distillation apparatus
A-74
02-2414-1
-------
of 1M sodium dihydrogen phosphate and 2 ml of 1% chloramine-T
solution were added. Within 30 seconds, 5 ml of the pyridine-
barbituric acid were added. The analyte solution was then
diluted to 50 ml and the color allowed to develop for 10 minutes.
The absorbence was measured at 578 nm with a double-beam spectro-
photometer. Concentration was determined by comparison to
standards.
Total Organic Carbon--
The organic carbon present in the preserved sample was
oxidized to carbon dioxide with potassium persulfate and phos-
phoric acid. The oxidation procedure was performed in a sealed
ampule at an elevated temperature. The resulting COa was measured
by passing the gas through the absorption cell of the nondisper-
sive infrared analyzer. Atmospheric C02 was excluded and water
vapor was removed before the gas entered the cell. The quantity
of COa was measured by a recorder equipped with a disc-chart
integrater. Peak areas of the sample were compared with the peak
areas of standards prepared in the same fashion.
3.4 RESULTS AND ERROR ANALYSIS
High accuracy of the trace metal analysis was assured
by analyzing a sample of National Bureau of Standards (NBS)
water, SRM 1643, in conjunction with the water samples. Table
A-22 gives a comparison between the NBS certified value and the
value obtained by Radian. Duplicate digestions and analyses
were performed on the plant inlet water, raw cooling tower blow-
down, and raw ash pond effluent. The duplicate analyses provided
a measure of precision of the analytical techniques. Detection
limits and precision data are listed in Table A-23.
A-75
-------
TABLE A-22. COMPARISON OF NBS WATER SAMPLE SRM 1643
WITH RADIAN RESULTS
As
Sb
Be
Cd
Cr
Cu
Pb
Hg
Ni
Se
Ag
Tl
V
Zn
NBS Value, ng/g
76 ± 1
NLa
19 ± 1
8 ± 1
15 ± 1
16 ± 1
20 ± 1
2C
49 ± 1
12 ± 1
3.4 ± .4
NL
50 ± 1
65 ± 3
Radian Value, ng/g
86 ± 1
NAb
16 ± 2
7 ± 2
14 ± 3
22 ± 4
18 ± 2
2.7 ± .3
53 ± 6
<8)d
(5)
NA
(53)
(59)
aNL = Not Listed
bNA = Not Analyzed
c 'Not certified due to possible container contaminant
( ) Only one value available
A-76
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TABLE A-23. DETECTION LIMITS AND ACCURACY OF
DATA FOR INORGANIC ANALYSES
Detection limit, ppb Accuracy 5xDL
As 1.0 = 100% if £ 5 ppb = 20% if > 5 ppb
Sb 1.0 = 100% if £ 5 ppb = 20% if > 5 ppb
Be 0.5 = 100% if £ 2.5 ppb = 20% if > 2.5 ppb
Cd 0.3 = 100% if £ 2.5 ppb = 20% if > 2.5 ppb
Cr 2.0 = 100% if £ 10 ppb = 20% if > 10 ppb
Cu 4.0 = 100% if £ 20 ppb = 20% if > 20 ppb
/
Pb 3.0 = 100% if £ 15 ppb = 20% if > 15 ppb
Hg 0.2 = 100% if £ 1 ppb = 20% if > 1 ppb
Ni 0.5 = 100% if £ 2.5 ppb = 20% if > 2.5 ppb
Se 2.0 = 100% if £ 10 ppb = 20% if > 10 ppb
Ag 0.2 = 100% if £ 1 ppb = 20% if > 1 ppb
Tl 1.0 = 100% if £ 5 ppb = 20% if > 5 ppb
V 4.0 = 100% if £ 20 ppb = 20% if > 20 ppb
Zn 2.0 = 100% if £ 10 ppb = 20% if > 10 ppb
CN~ 1.0 = 100% if £ 5 ppb = 20% if > 5 ppb
TOC 20 ppm = 100% if £100 ppb = 20% if > 100 ppb
A-77
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From previous calculations, analytical accuracy
decreases as the results approach the detection limit. Gener-
ally, the accuracy is ±100% if the result is within five times
the listed detection limit. For concentrations in excess of
this value, the accuracy is ±20%. Most of the results obtained
were near the detection limit. These values are well below pub-
lished levels of trace metals contamination, such as those shown
in Table A-24.
Detection limits are listed for cyanide and TOC data.
Standard cyanide samples were not available. However, recovery
studies performed previously have shown greater than 95% recov-
ery of cyanide from the distillation. Standard TOC samples were
not available. Replicate analyses of samples and multiple stan-
dards were included to insure analytical quality.
A-78
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TABLE A-24. WATER QUALITY CRITERIA
QUALITY CRITERIA FOR WATER3
Domestic Freshwater
Water Supply Irrigation Soft
As
Sb
Be
Cd
Cr
> Cu
•-j Pb
VO
HB
Ni
Se
Ag
Tl
V
Zn
N
TDS
50 100
100 11
500, soil pH>7
10 0.4 - 4.0
50 100
1000
50
2.0 .05
10
50
5000
5 5
250 ppm
Hard Marine Remarks
All values in ppb, unless otherwise noted
1100
1.2-12 5 Freshwater standards, species dependent
100
.1 of 96 hr LC5o for aquatic
.01 of 96 hr LCSO for aquatic
.05 .10
.01 of 96 hr LC50 for aquatic
.01 of 96 hr LC5o for aquatic
.01 of 96 hr LC50 for aquatic
.01 of 96 hr LCso for aquatic.
5 5
For Cl~ and S07t salts
aiiPA, "Quality Criteria for Water", EPA-440/9-76-023. Washington, D.C., 1976.
-------
REFERENCES
Al. Environmental Protection Agency, Environmental
Monitoring and Support Laboratory. Sampling and
Analysis Procedures for Screening of Industrial
Effluents for Priority Pollutants, revised.
Cincinnati, Ohio, April 1977.
A2. Cleland, J.G. and G.L. Kingsbury. Summary of Key
Federal Regulations and Criteria for Multimedia
Environmental Control, draft report. EPA Contract
No. 68-02-1325, Task 51, Subtask 5. Research
Triangle Institute, Research Triangle Park, North
Carolina, June 1977
A-80
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and Laboratory Studies for the
Development of Effluent Standards for the Steam Elec-
tric Power Industry
1. REPORT NO.
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
EPA-500/7-78-209
2.
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
6. PERFORMING ORGANIZATION CODE
.
November 1978
. AUTHORiSI
Frank G. Mesich and Milton L. Owen
8. PERFORMING ORGANIZATION REPORT N
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Radian Corporation
PO Box 9948
Austin, Texas 78766
10. PRCGRAM ELEMENT NO.
EHE624A
11. CONTRACT/GRANT NO.
68-02-2608, Task 22
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final: 7/77 - 4/78
14. SPONSORING AGENCY CODE
EPA/600/13
15.SUPPLEMENTARY NOTESigRL-RTP project officer is Theodore G. Brna, Mail Drop 61,
919/541-2683.
16. A8STRAC i
The report gives results of an evaluation of carbon absorption, chemical pre
cipitation, reverse osmosis, and vapor compression distillation (VCD) as removal
technologies for priority pollutants from wastewater streams of utility power plants.
All but VCD were bench-scale tested for the removal of low concentration (1-50 ppb)
pollutants from cooling tower blowdown and ash pond effluents at three coal-fired
plants. The removal of organic pollutants (by activated carbon and reverse osmosis)
and inorganic pollutants (by chemical precipitation and reverse osmosis) were eval-
uated at these plants. An operational VCD unit handling a combined waste stream was
tested for the removal of both organic and inorganic pollutants at a fourth coal-fired
plant. Samples of plant make-up water, cooling tower blowdown, ash pond effluent,
and effluent waters from the treatment technologies were analyzed for priority orga-
nic arid inorganic pollutants. Only eight pollutants were measured in concentrations
greater than 10 ppb; none of these were common to all the plants studied. Carbon
absorption and reverse osmosis removed priority pollutants, but low concentrations
prevented definitive conclusions on their removal effectiveness. Chemical precipita-
tion, reverse osmosis, and VCD effectively reduced low concentration anorganic com-
pounds, including arsenic, copper, and lead, all of which were present in significant
concentrations in at least one wastewater stream. _
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Croup
Pollution, Coal, Combustion, Standards
Electric Power Plants, Waste Water
Water Treatment, Activated Carbon
Activated Carbon Treatment, Precipitation
Osmosis, Distillation, Ashes, Ponds
Cooling Towers
Pollution Control
Stationary Sources
Chemical Precipitation
Reverse Osmosis
Vapor Compression Dis-
tillation
13B,21D, 21B, --
10B, --
07A, 07D
— ,13H, — , 08H
ISA
13. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS fTliis Report/
Unclassified
1. NO. O* PAGES
189
20. SECURITY CLASS iTIiii pagei
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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