PB86-171436
Grcundwater and Leachate
Treatability Studies at
Four Superfund Sites
Baker (Michael), Jr., Inc., Beaver, PA
Prepared for
Environmental Protection Agency, Cincinnati, OH
Mar 86
J
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PB86-171436
EPA/600/2-86/029
March 198b
GROUNDHATER AND LEACHATE TREATABILITY STUDIES
AT FOUR SUPERFUND SITES
by
Alan J. Shuckrow, Andrew P. Pajak,
and C. J. louhill
Michael Baker, Jr., Inc.
Beaver, Pennsylvania 15009
Conf act No. 68-03-2766
Project Officer
Stephen C. James
Lana Pollution Control Division
Hazardous Waste Engineering Research Laboratory
Cincinnati, Ohio 45268
HAZARDOUS WASTE ENGINEERING RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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TECHNICAL REPORT DATA
(Heist n*d li-.anititoia on tar rtrtnt btfort completing!
i. REPORT NO.
EPA/600/2-86/029
2.
I RECIPIENTS ACCESSION NO
4. TITLE AND SUBTITLE
6ROUNDWATER AND LEACHATE TREATABILITY
STUDIES AT FOUR SUPERFUND SITES
5. REPORT DATE
March 1986
6. PERFORMING ORGANIZATION CODE
7. AUTNOR(S)
Alan J. Shjckrow, Andrew P. Pajak. C. J. Tounlll
• PERFORMING ORGANIZATION REPORT NO
> PERFORMING ORGANIZATION NAME AND AODRl-SS
Michael Baker Jr., Inc.
Beaver. PA 15009
10. PROGRAM ELEMENT NO.
Y105
II. CONTRACT/GRANT NO
68-03-2766
12. SPONSORING AGENCY NAME AND ADDRESS
Hazardous Waste Engineering Research Laboratory
Land Pollution Control Division
U.S. Environmental Protection Agency
Cincinnati. OH 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final T/7Q - !
12/83
'CODE
14. SPONSORING AGENCY CODE
EPA/600/12
IS SUPPLEMENTARY NOTES
Stephen C. James. Project Officer (513/569-7877)
16. ABSTRACT
Selected wastewater treatment processes were evaluated in bench-scale
tests using contaminated groundwaters and leachates from four hazardous
waste problem sites. The processes investigated were selected on-the basis
of an extensive literature review and desktop analysis of 18 candidate
processes. This proceeding woric Is described in a report entitled "Con-
centration Technologies for Hazardous Aqueous Waste Treatment" (EPA 600/2-81-019),
The processes reported here include adsorption, biological treatment,
coagulation and precipitation, filtration, ozonation, sedimentation, and
stripping. The processes were used singly and in various process train
configurations.
IT.
KEY WORDS ' 4O DOCUMENT ANALYSIS
DESCRIPTORS
b IDENTIFIERS/OPEN ENDED TERMS
C COSATi Field/Group
18. DISTRIBUTION STATEMENT
Release to Public
19 SECURITY CLASS iTtlll Rrporll
Unclassified
21 NO O* PAGfcS
148
20 SECURITY CLASS iThil ptftl
Unclassified
22 PRIkC
EPA P*n> 2220-1 {B... 4.77) PHKVIOUI EDITION n OBSOLETE
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DISCLAIMER
The information in this document has been funded wholly or in part by the
United States Environmental Protection Agency under Contract No. 68-03-2766 to
Michael Baker, Jr., Inc. It has been subject to the Agency's peer and admin-
istrative review, and it has been approved for publication as on EPA docucent.
Mention of trade names or commercial products does not ccnstitute endorsement
or recommendation for use.
ii
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FOREWORD
The U.S. Environmental Protection Agency was created because of Increas-
ing public and governnent concern about the dangers of pollution to the health
and welfare of the American people. Noxious air, foul water, and spoiled land
are tragic testimonies to the deterioration of our natural environment. The
complexity of chat environment and the Interplay of Its components require a
concentrated and integrated attack on the problem.
Research and development is that necessary first step in problem solu-
tion, and it Involves defining the problem, measuring its impact, and search-
Ing for solutions. The Municipal Environmental Research Laboratory develops
new and improved technology and systems to prevent, treat, and manage waste-
water and solid and hazardous waste pollutant discharges from municipal and
community sources, to preserve and treat public drinking water supplies, and
to minimize the adverse economic, social, health, and aesthetic effects of
pollution. This publication is one of the products of that research and is a
most vital communications link between the researcher and the user community.
Numerous unit processes have been tested and demonstrated for treating
municipal wastewaters, and public and industrial water supplies. However,
these applications do not accurately duplicate the conditions associated with
contaminated groundwater and leachate treatment. The purpose of this research
was to test the applicability of several unit processes to the types of
groundwater and leachate currently beirg discovered and investigated around
the country. The results of this Investigation will aid future efforts to
formulate viable, cost-effective solutions to groundwater contamination
problems.
Selected wastewater treatment processes were evaluated in bench-scale
tests using contaminated groundwaters and leachates from four hazardous waste
problem sites. The processes investigated were selected on the basis of an
extensive literature review and desktop analysis of 18 candidate processes.
This preceding work is described in a report entitled "Concentration Tech-
nologies for Hazardous Aquecus Waste Treatment" (EPA 600/2-81-019). The
processes reported here include adsorption, biological treatment, coagulation
and precipitation, filtration, ozonation, sedimentation, and stripping. The
processes were used singly and in various process train configurations.
David G. Stephan, Director
Hazardous Waste Engineering Research Laboratory
iii
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PREFACE
Our Nation faces a rising incidence of poor hazardous waste disposal
practices that are harmful to groundwater resources and their beneficial uses.
The contamination source must be controlled to mitigate further damage at a
particular problem site. At many sites, it also is necessary to prevent
further contaminant migration and to provide water of sufficient quality and
quantity to meet user demands. One way to accomplish these goals may be
treatment of the contaminated groundwater.
Numerous unit processes have been tested and demonstrated for treating
municipal and industrial wascewaters, contamination resulting from sudden
material spills, and public and industrial water supplies. However, these
applications do not accurately duplicate the conditions associated with
contaminated groundwater treatment. The purpose of this research was to test
several unit processes judged in an earlier phase of this project ro be most
applicable to the types of groundwat^r problems currently being discovered and
investigated around the country. Tests were conducted using contamirated
waters from four problem sites for hazardous waste disposal. The intent was
to investigate process performance under various wastewater matrix conditions
-- not to optimize performance at a particular site. The work demonstrated
that site-specific conditions must be investigated to evaluate process per-
Tormance accurately.
The results of this investigation will aid future efforts to formulate
viable, cost-effective solutions to groundwater contamination problems.
iv
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ABSTRACT
Selected wastewater treatment processes wsre evaluated in beach-scale
tests using contaminated groundwaters and leachates from four hazardous wiste
problea sices. The processes investigated were selected on the basis of an
extensive literature review and desktop analysis of 18 candidate processes.
This preceding work is described in a report entitled "Concentration Tech-
nologies for Hazardous \queous Waste Treatment" (EPA 600/2-81-019). The
processes reported hero include adsorption, biological treatment, coagulation
and precipitation, filtration, ozor.ation, sedimentation, and stripping. The
processes were used singly and in various process train configurations.
Vastewaters used in the studies wore obtained from the following problem
hazardous waste disposal sites:
o Ott/Story Site, Muskegon, Michigan - Past chemical company Disposal
practices caused contamination of groundwater with dozens of organic
priority pollutants, a large portion of which are volatile.
o Gratiot County Landfill, Gratiot County, Michigan - Polybrominated
biphenyls were disposed of at a xunicipal/industrial landfill.
Investigations had shown that PBB's had entered the groundwater.
o Marshall Landfill, Boulder, Colorado - Leachate from a municipal
landfill containing industrial residues threatened a surface water-
way that conveyed water from a reservoir to a public water supply
system. Organic priority pollutants were found in the leachate.
o Olean Vellfield, Clean, New York - An aquifer serving as a municipal
water supply source was contaminated with trichloroethylene.
Process performance w&s measured under a range of operating conditions.
Total orginic carbon (TOC) was generally used as a surrogate for routine
process monitorr-ng, but specific compounds were examined at selected tin? s.
The report provides details of the study methods and process performance
results. A general conclusion was that site-spa-.if ic conditions greatly
influence process performance. Thus site-specific studies should be conducted
in most cases to evaluate and select a viable, cost-effective approach for a
particular problem site.
This report was submitted in fulfillment of Contract No. 68-03-2766 by
Michael Baker, Jr., Inc., under the sponsorship of the U.S. Environmental
Protection Agency. This report covutb the period March, 19/9 to December,
1983, and work was completed as of Deceooer, 1983.
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CONTENTS
Foreword Ill
Preface Iv
Abstract v
Figures vii
Tables x
Acknowledgements xli
1. Introduction 1
2. Conclusions 6
3. General Methodology 9
4. Studies Using Contaminated Groundvater from the
Ott/Story Site 30
5. Studies Using Croundwater from the Cratlot
County Landfill 100
6. Studies Using Uachate from the Marshall Landfill 104
7. Studies Using Croundwater from the Olean Wellfleld.... 118
References 123
Appendix 124
vl
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FIGURES
Page
Typical GAC Continuous Flow Experimental Apparatus... 18
Davls-Svlsher Reactor 23
One Liter Biological Reactor 24
CAC/Anaeroblc Filter Schematic 25
Schematic of Ozonacion Assembly 27
Continuous Flow, Packed Column Steam Stripping
Apparatus 29
7 Continuous Steam Stripping of Contaminated
Crourdwater at Steady State 39
8 Adsorption Isotherms, Raw Composite Groundwater.
pH 10.0 54
9 Adsorption Isotherms, Rav Composite Groundwater,
pH 7.0 55
10 Adsorption Isotherms, Raw Composite Groundwater,
pH 4.0 56
li Adsorption Isotherms, Composite Groundwater
pretreated by Ozonacion or Aeration 57
12 Adsorption Isotherms, Composite Groundwater
Pretteated by Ozonation/Activated Sludge and Upflow
Anaerobic Filter 58
13 Adsorption Isotherms, Well OU9 59
14 Adsorption Isotherms. Well Wl7d, pH 7.0 60
15 Adsorption Isotherms, Well W17d, pH 9.4 61
16 Adsorption Isotherms: Comparison of the Best
Carbon and the Best Resin Aerated/Oz^ne Pretreated... 63
vli
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FIGURES
(continued)
Page
Typical TOC Performance (Breakthrough) Curve 69
Performance of GAC/Activated Sludge Process 70
Comparison Between Carbon and Resin Adsorption 71
TOC Adsorption by Granular Activated Carbon 72
TOC Adsorption by Granular Activated Carbon 73
TOC Adsorption by GAC for Composite Groundwater and
Individual Wells 77
23 Activated Sludge TOC Removals 81
24 Activated Sludge Effluent TOC Concentrations 82
25 Performance of GAC/Activated Sludge Process Train.... 84
2ft TOC Removal by CAC/Activated Sludge Process Train.... 85
27 Performance of GAC & Activated Sludge Process
Modifications 86
28 Ferformaiice of GAC/Anaerobic Filter Process Train.... 91
29 Anaerobic Filter Operation 93
30 Performance of GAC/Anaerobic Filcer/Activated
Sludge Process Train 94
31 Comparison Between Process Trains Using Ozone 97
32 Adsorption Isotherm, Composite Groundwater
Pretreated by Ozone Activated Sludge 99
33 Adsorption Isotherms 107
34 Breakthrough Curve - 2 Column GAC System Ill
35 GAC Performance - 2 and 3 Column Systems 112
36 GAC Performance - J Column System 113
37 TOC Removal vs. Seepage Volume Piocessed - 3 Column
GAC System 114
viii
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FIGURES
(continued)
Page
CAC Performance Comparison 117
TCE Adsorption Isotherm 120
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TABLES
P>ge
Sice Characteristics and Study Suxmary ............... 12
Conversion Factors ................................... IS
Granular Activated Carbon Properties ................. 17
Powdered Activated Carbon Properties ................. 20
Properties of Adsorption Resins ...................... 21
Comparison of Organic Pollutant Analysis of Saw
Croundwater From Wells OW9 and W17d .................. 31
7 Ott-Story Site Croundwater General Characteristics... 32
8 Renoval of Groundvat»r Organic Pollutants by
Stripping ............................................ 36
9 Sunm»>ry of Isotherm Studies
10 Isothera Sorptlon Capacity (Carbon Sorption Using Raw
Composite Groundwater) ............................... 44
11 Isotherm Sorption Capacity (Resin Sorptlon L'sirg Raw
Composite Groundwater) ............................... 45
12 Isotherm Sorption Capacity (Composite Croundwater
Pretreated By Ozonatlon or Aeration) ................. 46
13 Isothera Sorption Capacity (Composite Grcundwater
Pretreated by Ozonation/Activated Sludge and 'Jpflow
Anaerobic Filter) .................................... 47
14 TOC Removed During Sequential Batch Studies of
Sorption and Air Stripping .......................... AS
15 Removal of TOC and Speclflr Organic Pollutants Curing
Sequential Batch Studies ............................. 49
16 Isotherm Sorption Capacity (Groundwater From Wells
OW9 and Wl/d) ........................................ 52
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TABLES
(continued)
Isotherm Sorption Capacity (OW9 and VI7d Grcundwatore
Fretreated by Activated Sludge) 53
18 Continuous Flow Adsorption Studies 65
19 TOC and Priority Pollutant Data for Granular Activated
Carbon/Activated Sludge Process Train 74
20 Studies of Activated Sludge Process 78
2L TOC and Specific Pollutant Data for Granular
Activated Carbon/Activated Sludge Proceed Train 88
22 TOC Removal by XE-347 Resin 90
23 Suasnary of Batch Ozonation and Adsorption Studies.... 96
24 Cratiot County Landfill Quality of Middle Sand
Aquifer 101
25 Gratiot County Landfill Groundwater Metals Content -
Raw and Treated 103
26 Analyses of Waters at Marshall Landfill 105
27 Isothems at Prevailing pH (7.95) - Marshall
Landfill 108
28 Granular Activated Carbon Performance - Two Colunn
System 110
29 TOC and Priority Pollutant Analyses for Three-Column
GAC System 116
xi
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ACKNOWLEDGEMENTS
The authors wish to acknowledge the cooperation and assistance provided
jy Darrel E. Cardy, Gary Klepper, Leonard Lipinski, Peter Marcus, and Jan
Brower at the individual sites, and Dr. Ronald Neufeld for providing advice
and assistance in compiling this final project report. Special thanks go to
Stephen C. Janes, Project Officer, for his assistance and cooperation through-
out the entire course or this work.
xii
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SECTION 1
INTRODUCTION
PROJECT BACKGROUND
This document is Che third and final major report resulting from a
program to evaluate and verify concentration techniques for hazardous con-
stituents of aqueous waste streams. The first two were entitled: "Con-
centration Technologies for Hazardous Aqueous Waste Treatment," (EPA-600/
52-81-019. March 1981), and "Management of Hazardous Haste Leachate" (EPA
Technical Resource Document SW-871, September 1980). Taken together, the
three reports mirror increased and significant attention focused on hazardous
wastes during the past 4 to 5 years. Hence the following discussion is
intended to describe not only how the three reports fit together, but also the
historical setting that guided their formulation.
As originally conceived, this program was to identify, evaluate, and
verify those promising technologies that could be used to concentrate rela-
tively dilute hazardous aqueous waste streams before detoxification or dis-
posal. Though this purpose has been maintained and successfully achieved
within the context of the three reports, several major developments have had
considerable impact on the focus of the overall program. For example, during
the period when a contractor was being selected co conduct this program
(summer of 1978), media attention first focused on Love Canal. Moreover, in
the early stages of the project (spring of 1979), it became clear that Love
Canal was not an Isolated problem. Because of rising awareness of potential
implications of poor hazardous waste disposal practices, reports of additional
problem sites began to mount.
As a result of this growing concern, the House Subcommittee on Oversight
and Investigation of the Interstate and Foreign Commerce Committee conducted
hearings designed to determine the magnitude of the hazardous waste disposal
site problem. Following the hearings, the subcommittee conducted a "Waste
Disposal Site Survey" and issued their report in October 3979. The survey
found that the 53 chemical companies queried (1,605 plants) produced approxi-
mately 66 million tons of process wastes in 1978 alone. Since 1950, these
companies had disposed of about 762 million tons of chemical wastes in 3,383
locations. Of these sites, 32 percent (1,099) were known to be closed, and
another 9 percent (319) may be closed. The closed-site Inventory of wastes
was believed to be about 100 million tons. Furthermore, it was estimated that
about 4.8 million tons were taken by private haulers to unknown destinations.
In a separate assessment, the U.S. Environmental Protection Agency ("h'PA)
concluded that between 30 and 40 million metric tons of hazardous wastes would
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be generated in 1980. This annual generation rate was expected to double by
the year 2000. EPA believed that there were as many as 32,000 hazardous waste
dusp sites throughout the country. Of these. 1,200 tc 2,000 were thought to
present possible health or environmental problems.
These estimates prompted acute public concern, which resulted in (1) the
promulgation of strict regulations in November 1979 implementing the provi-
sions of the Resource Recovery and Conservation Act of 1976 (RCRA), and
(2) passage of the Comprehensive Environmental Response, Compensation, and
Liability Act of 1930 (CERCLA). Eventually, in the fall of 1982, EPA issued a
list of 419 abandoned hazardous waste sites, the cleanup of which would be
funded by the $1.6-billion program known as the Superfund.
The present research program began just as the magnitude of the problems
of hazardous waste sites were being recognized. The project progressed as
knowledge of the nature of the problems started to become refined, and final-
ly, program results were able to be focused at four Superfund sices. In these
final stages, treatability studies were performed on actual groundwater and
leachates contaminated by several different types of hazardous wastes. The
ecd result of the program is that a number of unit processes capable of having
broad application in concentrating aqueous contaminants at hazardous waste
disposal sites were identified and evaluated. This report focuses on the
final stages of the program in which these unit processes were demonstrated in
bench-scale treatability studies for four Superfund sites. In one ca«e, the
treatability studies were conducted onsite for an 18-month period.
Before introducing the scope of work conducted in the final stages ri the
program, work conducted earlier in the project is briefly discussed.
EARLIER WORK
In work for the first report, "Concentration Technologies for Hazardous
Aqueous Waste Treatment", It was found that the most iridespread hazardous
waste problem faced by the public sector is contamination from unsecured waste
disposal sites. This contamination generally is in the form of leachates and
contaminated ground and surface waters. However, there is no such thing as a
"typical" hazardous waste problem—each site is unique. Research efforts
showed that of the problem sites examined in the early stages of this project,
wastes encountered were diverse in terms of composition and concentration-
varying from site to site and often varying over time at any given site.
Waste streams at some sites contained a broad spectrum of organic and inor-
ganic compounds, while others had only a few constituents of concern. These
waste streams generally fell into one of the following two composition cate-
gories: high organic - low inorganic or low organic - i.i«?h inorganic.
On the basis of an extensive literature review and desktop analysis, the
following unit processes were identified as having potential broatl application
in concentrating aqueous hazardous wastes:
o biological treatment
c carbca adsorption
2
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o chemical coagulation
o membrane processes
o resin adsorption
o stripping.
Although not a concentration technology, because of its demonstrated ability
to enhance creatability of numerous organic compounds, chemical oxidation
(e.g., ozocation, possibly with UV irradiation) also was judged to have
potential application. Generally, the above processes must be supplemented
with ancillary processes such as sedimentation and filtration.
Because of the diversity of waste streams, it was evident that in most
cases no single unit process would be sufficient to treat the contamination
problems encountered. As a result, five process trains were formulated as
being broadly applicable to most types of known contamination. These were:
o biological treatment/carbon scrption
o carbon sorption/blological treatment
o biophysical treatment
o membrane/biological treatment
o stripping/carbon sorption.
It further was concluded that because hazardous waste contamination
problems differ substantially from place-to-place, treat&billty studies in
some fom almost always are a prerequisite to selection of an optimum treat-
ment approach. Hence, in order to demonstrate the applicability of the unit
processes and their combinations, it was decided that it was important to
evaluate there methods at actual hazardous waste problem sites. Results of
this decision are reported herein.
Based upon the findings of the first stages of this project described
above, EPA requested that they be incorporated into a technical resource
document on the "Management of Hazardous Waste Leachate". This manual was
intended to provide guidelines for permit officials and owners and operators
of hazardous waste management facilities. Leachate was defined as the liquid
contained within a landfill or Impoundment which percolates into surrounding
soil and is collected for subsequent treatment.
The manual provided a logical thought process for arriving at reasonable
treatment process trains for specific leachates. Furthermore, sufficient
factual information was provided so that manual users could readily identify a
few potential treatment alternatives which could be refined to make a final
choice. The manual began with a brief discussion of factors that influence
leachate generation. This was followed by data on leachate characteristics at
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actual waste disposal sites. Major options for dealing with hazardous waste
leachate were Identified.
A major section of the manual dealt with technology profiles for proces-
ses having potential application to leachate treatment. These process des-
criptions were supplemented by treatabllity data, information on by-products,
costs, and process applicability. Factors which influence treatment process
train selections and a suggested cpproach for systematically addressing such
selections were discussed. A few hypothetical .ind actual leachate situations
were used as examples for applying the approach to the selection of appro-
priate treatment processes. Other sections of tha manual addressed moni-
toring, safety, contingency plans/emergency provisions, equipment redundancy/
backup, pernits, and surface runoff.
The manual was prepared concurrently with the treatabllity studies
conducted at the Ott/Story site. As a result, the nanual profited from
experience gained during the laboratory and field work. Conversely, the
manual helped to structure subsequent treatability studies at other locations.
TREATABILITY STUDIES
The capability of the unit processes identified as having potential,
either individually or as process trains, to treat contaminated groundwater or
leachates was demonstrated at four Superfund sites. These were:
o Ott/Story Site, Mujkegon, MI
o Gratiot Cour.ty Landfill, MI
o Marshall Landfill. Boulder County. CO
o Olean Wellfleld, Olean, NY.
The objective was to investigate process performance under various
wastewater matrix conditions — not to optimize performance at a particular
site. The work demonstrated that site-specific conditions must be investi-
gated to evaluate process performance accurately. Results of these studies
are the subject of this report.
At the Ott/Story site, groundwater was severely contaminated by numerous
organic compounds. Because of the complex nature of the problem and the
willingness of the current sice owner to cooperate wich EPA. extensive treaca-
bility studies were conducted on-site for an 18-monch period. Activated
carbon and resin adsorption, aerobic and anaerobic biological treatment,
chemical oxidation, and stripping were investigated at the bench scale. The
process train which perforced best was granular activated carbon adsorption
followed by activated sludge treatment. High levels of treatnenr were main-
tained for short periods of tine.
The Cratiot County landfill problem livolved contamination of groundwatet*
by polybrominated biphenyls (PBR). PBB con'?ainaticn was the result of c>ie
disposal of PBB in the land till by a chemical company. Because PBB is
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relatively insoluble, PBB contamination was found Co be associated primarily
with sediment and not with the water in samples taken in this study. There-
fore, it was concluded that physical separation processes should effect
significant leve's of PBB removal.
At the Marshall landfill site, lov levels of hazardous material con-
tamination were found within high-strength organic contamination indicative of
sanitary landfills. Ihe primary method used in these treatability studies was
granular activated carbcn sorption. Results of these efforts were inconclu-
sive.
Croundwater at the Olean wellfield was contaminated by trichloro-
ethylene from an unknown source. Treatability studies showed that air strip-
ping was the most cost-effective method for removing the con-
taminant .
The report which follows describes the methodologies used at each of the
four sites to screen treatment methods, discusses the advantages and disadvan-
tages of the unit processes in differing situations, and reconsaends potential
approaches for other applications.
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SECTION 2
CONCLUSIONS
1. Each site with hazardous aqueous waste problems (e.g., leachates or
contaminated surface or groundwater) is unique in terms of problem
nature, magnitude, and potential solutions. Moreover, individual unit
process performance is specific to the wastewater matrix, and this matrix
cannot be accurately duplicated with a synthetic wastewater. Thus,
treatability studies using actual site wastewaters were necessary r'r-r a
good nssessiceit of unit process performance and for development of
process design criteria.
2. A single unit process is not capable of treating the complex wastewater
matrix present at many problem sites. In such cases, a train of unit
processes oust be assembled.
«
3. The effluent quality objectives for treating hazardous waste leachates
and contaminated groundwater must be assessed from several perspectives.
In many caves, it was found that even though the effluent had a high TCC
concentration (several hundred milligrams per liter), organic priority
pollutants were absent at typical detection levels. The presence of
non-priority organics and their iepact when treated water is discharged
either to a surface water body, groundwater, or publicly-owned treatment
works (POTW'S) must be assessed. It may not be possible or necessary to
attain the effluent TOC levels typically associated with POTW discharges.
Attention should be focused instead on the toxicity and risk associated
with a particular level of effluent quality, and this assessment should
be integrated with the treatment process evaluation procedure to assure
selection of a cost-effective treatment approach. Pursuing the assess-
ment in this manner also necessitates that bench or pilot-scale treat-
ability studies be conducted using site-specific wastewater.
4. Available literature describing the performance of unit processes is
limited. Much of the currently published information describes evalu-
ations using either single compound synthetic solutions or gross indi-
cator parameters when a complex wastewater matrix is employed. Infor-
mation from full-scale treatment operations is limited by the paucity of
these operations and confidentiality constraints imposed Sy process
vendors and private sector clients. Available literature can serve only
as a starting point to desiga a site-specific evaluation study; it should
not be used to decide the degvee of treatment that can be achieved
cost-effectively or for final design purposes. Infora ition in this
report should therefore be used for initial technology screening and for
fcrsulatiriK site-specific evaluations, not for identifying the preferred
option for a problem site, even if the situations arc similar.
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5. Air stripping successfully removed volatile organic priority pollutants.
In one casf», numerous volatile priority pollutants and in another case
trichloroethylene were reduced from milligram/liter levels to non-
detectable levels. Air emission considerations must be assessed on a
case-by-case basis to determine process viability and cost-effectiveness.
6. For a groundwater having a high TOC concentration (480-610 mg/1), steam
stripping resulted in a severalfold concentration of waste stream organ-
ics in the stripper overhead. However, bottoms stream flow was only six
percent less than the feed flow and bottoms TOC ranged from 300 to 400
mg/1. This may have been due partly to operational limitations of the
laboratory-scale apparatus.
7. Granular activated carbon (GAC) provided high degrees of organic priority
pollutant removal. However, when treating a groundwater with a high TOC
concentration (about 1,000 to 2,000 mg/1), GAC could not sustain hij;h TOC
removal levels. For example, TOC removal declined to less than SO
percent after processing five bed volumes; within 100 to 160 bed volumes,
TOC removal decreased to 10 to 15 percent. Even when TOC removal had
declined to 35 percent and effluent TOC was about 600 mg/1, generally
greater than 98 percent organic priority pollutant removal still was
attained.
8. Carbonaceous adsorption resins demonstrated TOC breakthrough character-
istics similar to those of GAC. However, TOC breakthrough occurred more
rapidly.
9. Biological treatment processes alone were capable of achieving only
minimal TOC removal, even though attempts were made to acclimate the
process and assure proper operating conditions. TOC removals *>y the
activated sludge process slightly exceeded removals provided by air
stripping alone. An anaerobic biological treatment process could not be
sustained on raw contaminated groundwater even under conditions believed
to be suitable for anaerobi: processes. At the Ott-Story site, bio-
inhibitory substances rather than usable substrate limitations were
believed to be responsible for affecting biological process performance.
10. GAC pretreatment of raw groundwater permitted development of an aerobic
biological treatment process that was capable of further treating GAC
effluent. Greater than 95 percent TOC removal was achieved by this
process during the period in which GAC removal of TOC exceeded 30 per-
cent. After this initial perl.d, process train performance declined as
GAC perforrear.ee declined. Several organic priority pollutants were
detected in off-gas from activated sludge reactors; these included
methylene chloride, 1,2-dichloroethane, benzene, tetrachloroethylene, end
toluene.
11. Anaerobic treatment (upflow anaerobic filter, UAF) of GAC-pretreated
groundwater was possible, but performance declined as GAC performance
declined. Overall, the GAC/UAF process train performed more poorly than
the GAC/AS process train, with an upper TOC removal limit of 81 percent.
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12. Pretreatment by ozone oxidation did not appear to enhance either adsorp-
tion or aerobic biological treatment processes.
13. Laboratory-scale tests generally require considerable quantities of
VMtewater. Vhen actual wastewaters are be ins used, logistical problems
rvy arise and errors nay be introduced because of transformations during
a&nple storage. Acceptable alternative preservation techniques are
limited because most will affect unit process performance. Freezing
samples shortly after ccllection and thawing them at room temperature
just before use worked well for sample preservation in one situation and
very poorly in another. Checks should be built into the technology
evaluation studies to assess potential errors associated with the study
methodology.
-------
SECTION 3
GENERAL METHODOLOGY
TECHNOLOGY EVALUATION PROCEDURE
As described in Section 1, earlier phases of this work Involved Identi-
fication and desktop evaluation of unit processes potentially suitable for
concentrating hazardous constituents of aqueous waste streams. Results of
that evaluation have been published in a report entitled "Concentration
Technologies for Hazardous Aqueous Waste Treatment" (1). The following con-
clusions from that report form the general premise for the technology evalu-
ation activities reported herein:
o Concentration technologies judged to have the greatest bxoad spec-
trun potential arc chemical precipitation, flocculacion, sedimen-
tation, filtration, biological treatment, carbon adsorption, and
resin adsorption.
o Reverse osmosis, stripping, and ultrafiltration are believed to have
more limited and specialized applicability.
o Ion exchange for removal of inorganic species also may have poten-
tial but usually, competing processes such as chemical precipitation
are more economical.
o Since hazardous waste contamination problems differ substantially
from place-to-place, treacability studies in some form are almost
always a prerequisite to selection of an optimum treatment approach
and/or for developing design criteria.
o Much of the experimental data on chemical treatabllity has been
generated from pure compound systems. Removal from multlcomponent
systems may differ substantially.
o Several concentration processes are promising for treatment of
hazardous aqueous wastes. However, for the application of interest,
often a single unit process will not be sufficient. In such in-
stances, process trains Bust be utilized.
Based upon these conclusions, it was decided that contaminant streams
used for the technology evaluations should be representative of the matrices
pr-jsenc ac actual problem sices racher chan pure compound systems, bynthesis
oi such complex matrices was judged to be infeaslble because of the various
-------
nuances associated with actual contaminated groundwater and leachates.
Consequently, it was decided that use of waters from actual hazardous waste
problem sites would provide the most representative and useful information on
the performance of treatment processes.
Technologies can be evaluated either at laboratory bench-scale or at
pilot plant scale. Bench scale studies were used in this effort covering a
wide range of independent variables because the objective was to assess the
performance of a number of unit processes under various conditions and not to
optimize a process for treating a particular waste stream.
Two alternative methods of conducting bench-scale technology evaluations
were identified:
1. shipping contaminated water to the Baker/TSA laboratory for experi-
mental studies, and
2. establishing a technology evaluation laboratory at the problem site.
During the course of this research, both approaches were used.
In most cases, laboratory evaluations began with batch tests of individu-
al unit process. For selected unit processes or process combinations, batch
sequential or continuous flow studies were undertaken. Physical-chemical
systems were operated i'or sufficient periods of time to reflect steady state
conditions. Biological treatment processes were operated to assure steady
states with acclimated biocultures. Study procedures varied depending upon
the contaminant stream being studied; details are discussed below.
Monitoring treatment process Influent and effluent chemical character-
istics was recognized at the outset to be potentially complex and costly.
Much of the literature reviewed during the earlier phases of this contract
described process performance on the basis of broad measurements such as COD
and failed to address the effects on specific chemical compounds. Accord-
ingly, it was recognized that specific compound data must be developed to
improve the existing information ba^e. To accomplish this within project time
and budget constraints, indicator/surrogate parameter measurements were
supplemented with specific compound analyses; the former were examined rou-
tinely and the latter were measured at critical times during process eval-
uations. Total Organic Carbon (TOC) was used as a surrogate when the waste-
water was predominantly organic; either heavy metals or organic priority
pollutants were analyzed when removal of specific compounds was of interest.
TOC was selected as a surrogate parameter because accurate results could be
obtained rapidly and relatively inexpensively; this allowed timely control of
laboratory study direction. Analytical procedures are discussed in greater
detail below.
SELECTION OF TESTING SITES
During the first phase of this contract, hazardous waste problem sites
where public agencies are (or would be) involved in some capacity In remedial
10
-------
actions were identified (1). This effort enabled development of a list of
potential sites for obtaining contaminated waters for technology evaluations.
As the study progressed, additional problem sites were identified. If
background data were provided and they indicated the presence of a problem
potentially amenable to treatment by concentration technology, the site was
added to the candidate list. Criteria used to select the test sites Included:
o availability of quantitative data describing problem nature and
magnitude,
o absence of pending litigation which would limit information trans-
fer,
o cooperative relationships between current site owners and the
regulatory agencies, and
o intention to undertake, or at least study, implementation of reme-
dial measures.
Using these criteria, the following sites were selected as sources of
contaminated water for bench-scale technology evaluations:
o Ott/Story Site, North Muskegon, Michigan;
o Gratiot County Landfill, Bethany Township, Michigan;
o Marshall Landfill. Boulder County, Colorado; and
o Clean Wellfield, Clean, New York.
Descriptions of each of these sites and the investigations undertaken using
each wastewater are presented in more detail elsewhere in this report.
Table 1 summarizes site characteristics and Che technologies examined.
ANALYTICAL PROCEDURES
As stated earlier, TOC was used regularly as a surrogate parameter to
monitor organics in a gross fashion while specific organic and inorganic
compound analyses were performed at selected tines In addition, several
parameters were measured frequently to characterize operating conditions of
the unit process being tested.
TOC was measured with an Ionics Model 1258 Total Carbon - Total Organic
Carbon Analyzer. All samples were analyzed almost immediately after collec-
tion. Except for vacuum filtration of selected unit process effluents to
remove suspended solids and required dilution to allow analysis on the pre-
ferred Instrument detection scale, there was no preservation, modification, or
storage of samoles prior to testing. Before select--inn of vseu'im filtration
for solids separation, potential stripping of volatile organics was examined.
11
-------
TABLE 1. SITE CHARACTERISTICS AND STUDY SUMMARY
It Ml
mi ctuiAcnmsTicji
llaele SHIM
Pollutant* of Concern
Oii/Siorjr
North Muakee.onl Nlcklgan
rant(Blut*d groundvaler
•UMIO-J* or|inlc prlor-
Itf and noi.-prlorlly
Crillol County Landfill
••than? Tovnahlp, Hlcklgan
ccnlMluted irotmdvittr
HI «nd **veril
keavy Mtala
Harebell Umirilt
toulder. Colorado
•eipa|e draining
fro* landfill
m-wrou* organic
priority pollutant*
Oltan Ucllflald
Clean. Ibv Tork
contaminated |rm*Ant«r
Iflcklorotlkjpln* (TCI)
ro
L*bor*lory Scudj locilloa
Vial* Slriaa
!la«pl* Hatdllnf
S»pl* Slurif*
coii*tllu*nt*
on-all*
»rtf\,m vllhpUn fro* Indlvldu*!
veil* covpotllfd for
lab aluillaa
|*n*r*ll]p ilorad I to 1
d.«a Jn |laia or poljr-
cnntalo*r*
lakir/TS* lah. B«*»r. f* Bak*r/TSA lak. *>*>«r. •* k»*r/TU la*. »*n*r.
vllhdrtwa fro* *al*ll*|
mil *1 at*:* afancy
alalf
•l.lpp*d to la
aavtral occaalnn* In \
§•1 »ipandvd (Nily-
fropiltne cart>o>a laawd-
laltly aflar rolUcllon;
(anaially rxtlord on*
day after collect loo
rark«r* fiotan upon
racalpi; lhavrd at
luoai ttffttttutt vn**i
iwadrd
aavplad ky romly *f*acy
Half at erad co*avr»cl*d
to I •pound ne
•kipped 10 latei/TM o»
•evaicl occatlona In )
fal ••pandvd pwly
prcvpylene carboy* !*M>d>
lately after rolled loo;
|an*relly received oo*
day after rollectio*
Initially rarkoyi noro
frcfin upon receipt; nov>
ever, heceuee of *l|alft-
rant TOC IfiBl during
thjuinii. Mor*nad carkny*
fron iuk*e^ucnt eupllnga
vvr* atored at rooei
leacwrature unlll unrJ
caipUd ky project itaff
•ad eunlcipal ea*iloyee*)
•t dlicnarg* line frou
city valet «ill
ahlpptd to taler/TM
Initially I* 0.) gal
gl*ae koltlee] teter
111 gal (kipped In »
gal dnau
atored In cloaed UBjaillnf
container *t ro«i l*c|i*r-
elure until na*d
(Conllm..d)
-------
TABLE 1. (Continued)
Oll/Storv Cut lot Couity landfill Harahall Landfill Oleaa ttallfltld
Iteei North Huakegun. Hlchlgaa Bethany Townahlp. Michigan Boulder. Colorado Oleaa, Hav Torp-
TtCIINlllOCIH KAMI NED I
ailaoipl Ion
granular acllvaleJ car'joa
povdvred acllvateil cacbon
realne
biological
aillvated aludge
trickling filter
anaerobic filler
coagulallun/praclpllatlon
filtration
monition
alrlpplng
air
• lea*
•ed Initial Ion
XIII
X I
X IS
X I
X
X
X
X I
X
X II
I
X X
unit proceaicfl combined
Into proceia cr«lna
-------
Organic priority pollutant analyses were performed by more than one
laboratory during the course of this contract. All analyses were performed
according to EPA protocol (2,3) using combined gas chromatography-mass spcc-
trometry (GC-MS) and gas chromotograpby (GC).
Heavy metal analyses were perlomed by Baker/TSA using flame or graphite
furnace atomic absorption spectrophotometry techniques. Other analyses during
the project (e.g., pH, suspended solids, ammonia nitrogen) were in accordance
with Standard Methods (A).
EXPERIMENTAL APPARATUS
The technologies itemized in Table 1 were evaluated at the bench scale
using equipment matching the conditions to be investigated. The following
briefly describes the experimental procedures and apparatus used in the
evaluation of each technology; additional details are provided when the
site-specific results are presented.
| It should be noted that throughout this report, units of measure which
typically are associated with unit process operation have been used; for
oxample. hydraulic loading to granular activated carbon columns is reported in
gallons per minute per square foot of surface area. A table to convert to the
International System of Units (SI) is provided in Table 2.
Adsorption - Activated Carbon
Granular Activated Carbon —
Granular activated carbon (CAC) adsorption studies generally began with
batch isotherm testing followed by cont inuous flow, small diameter column
studies. Isotherm tests were undertaken to determine:
o comparative performance of different sorbents,
o approximate contact times,
o effect of wastewater composition matrix, and
o approximate sorbent dose rates.
Data were used to develop Freundlich adsorption isotherms according to the
equation:
. . 1/n
x/m - kc
Where: x - amount of solute adsorbed
m - weight of carbon
c • equilibrium concentration of solute in
solution aftar adsorption
k, n - constants
16
-------
TABLE 2. CONVERSION FACTORS
To Convert From
Customary Unit
ef
ft
°F
gal
gal
gpd
gpd
gpm
gpm
gpm/sf
gpia/sf
inch
Ib
lb/1000 cf
Ib/day/cf
Ib/day/sf
sf
Multiply By
2.832 x 10-2
3.048 x 10-1
(°F-32) 0.5556
3.785 x 10-3
3.785
3.785 x 10-3
3.785
6.308 x 10-5
6.308 * 10-2
A
6.790 x 10-
6.790 x 10-1
2.54 x 10
4.536 x 10-1
1.602 x 10
1.602 x 10
4.883
9.290 x 10-2
To Obtain
SI Unit
«3
m
•c
m
1
m /Day
I/day
«3/s
1/8
3 2
n /s/ra
1/s/m2
CDQ
kg
g/a3
kg/day/m
kg/day/m
m2
15
-------
Continuous flow studies were undertaken to examine the effects of hydraulic
and solute loading rates, and contact times, and to develop solute break-
through curves.
Two granular activated carbon sorbents were used during the course of
this study:
o Filtrasorb 300 (FS-300) - Calgon Corporation
o GAC 30 - Carborundum Corporatiou
Properties of these carbons are summarized in Table 3.
For isotherm tests, carbons were used in the powdered form. Granular
carbons were pulverized and screened; that portion passing through 325 mesh
screen was used for isotherm tests. After classification, the powdered carbon
was oven dried overnight at 105°C, cooled, and stored in a desiccator until
needed. A slurry of this powdered carbon was prepared with distilled water
and used in the isotherm tests.
For batch Isotherm tests, an aliquot of contaminated water and the
desired dose of carbin were contacted in capped glass bottles of 100 or 250 ml
capacity. Mixing vas accomplished using a platform shaker operated at either
180 or 280 excursions/minute depending upon the carrier tray load. Mixing
time and wastewater pH also were varied during the studies. After the pre-
scribed contact period, powdered carbon was removed by filtration through
Whatsan 82 paper. Vastewater pH was adjusted only at the start of the contact
period.
It should be noted that preliminary tests investigated mixing with a
six-paddle stirrer at 100 rpm and vith a magnetic stirrer. However, these
techniques were not utilized because they did not provide adequate contact at
high sorbent Joses «ad allowed release of volatile organics from the open 900
ml glass beakers.
For the continuous flew studies, 1.90 or 2.54 cm diameter glass columns
operated individually and in series were used. Bed height was varied by
arranging the coluass in series. Sampling ports were provided before the
first column, at aid-points between columns in series, and after the last
colusa. Feedwater was pumped to the first colucn either from a storage
container or an upstream process using a chemical metering pump; column
effluent was discharged to laboratory drains, fed directly to a subsequent
treataent proo.ss, or stcred and fed over a period of time to a post-treatment
process. Prior to filling the columns, a weighed acount of GAC vas mixed with
distilled water and soaked to degas the carbon. Columns then were charged and
backwashed. Studies were conducted under a vented hood when volatile con-
stituents were knova or suspected to be present in the wastewater. Figure 1
illustrates a typical GAC continuous* flow experimental apparatus.
16
-------
TABLE 3. GRANULAR ACTIVATED CARBON PROPERTIES
PROPERTIES
U.S. Standard Series Sieve Size
Larger Chan No. 8 (aax.)
Smaller then No. 30 (aax.)
Iodine Number (og/g) (min.)
Abrasion Number (oin.)
Mean Particle Dlaaeter (min.)
Effective Size (csa)
Water Soluble Asb (max.)
Moisture Content (max.)
Base Material
Total Surface Area
(N2 BET Methanol. mz/gm)
Apparent Density (lb/ft3)
Backvashed and Drained Density (lb/ft3)
CAC
Flltrasorb
300
15*
«
900
75
1.5 - 1.7
0.8 • 0.9
0.5%
2.0X
bituminous coal
950 - 1050
NA
26 - 27
CAC
30
15Z
52
900
70
1.5 - 1.7
0.85
NA
2.0Z
coal
900 - JOOO
32
27
NOTE: Properties defined by manufacturer's specificacion literature.
NA: Not Available
17
-------
5/8" 1.0.-*
Glon
Tubing
Pump
i O—1
lr— &~
Somp!«
1 J Contoincr
||
•*• * '
v\\\\\\\\\\\\\
(
\
s
^
..•
h
* ,
\\\\\\\\\\\\\\
i
1
>
/
/
/
/
/
/
/
/
/
/
/
/
t
\
\
7
/
X
/
/
/
/
/
/
/
/
/
/
/
.'•'.
<
k_
1"
^
1-
'.'*'."
p
^
s
\
\
0r-^
•—
<•«
ci
•
•
•
c
E
3
"5
0
M
•
O
O
"•»
^B«
«ni
— -
tJ
•
a
c
0
A
!•
a
0
•
10
-— --
"-^
1 — 901
P<
•^~
i— ••
-^
npU
irtt
Efflutnt
Figure 1. Typical CAC Continuous Flow Experimental Apparatus.
-------
Powdered Activated Carbon —
Studies of powdered activated carbon (PAC) also involved batch isotherm
tests as described for GAC studies. However, continuous flow studies involved
addition of PAC to acti/ated sludge reactors for concurrent adsorption and
biological treatment.
Tbe two carbons used for these studies were:
o Hydrodarco C (HOC) - ICl Americas, Inc.
o Nuchar SA - Uestvaco
Table 4 summarizes properties of these carbons.
In continuous flow studies, PAC was added to the aeration chamber of the
activated sludge reactor and relieved from the settling chamber with the
settled sludge floe. Various PAC doses were tested; study conditions also
were controlled to evaluate various hydraulic retention times and activated
sludge mixed liquor suspended solids concentrations. Operation of the acti-
vated sludge system Is described later.
Adsorption - Resin
Batch isocherm and continuous flow column adsorption studies were con-
ducted using the following polymeric and carbonaceous resins produced by Rohm
and Haas Corporation:
o Amberllte XAD 4 - polymeric
o Ambersorb XE 340 - carbonaceous
o Ambersorb XE 347 - carbonaceous
o Ambersorb XE 348 - carbonaceous
Properties of chese resins are presented in Table 5.
Isotherm and column studies were conducted in a manner similar to those
described previously for CAC.
Biological Treatment
Biological treatment processes investigated included:
o activated sludge
o triclcling filter
o upflow anaerobic filter
19
-------
TABLE 4. POWDERED ACTIVATED CARBON PROPERTIES
TYPICAL PROPERTIES
Pareical Size (min Z -325 nesh)
Tamped Density (g/al)
Apparent Density (kg/m3)
Surface Area (m2/gm)
pH
Water Solubles (Z)
Ash (Z)
Total Pore Volume (cm3/g)
Base Material
Iodine Number (min)
Hydrodarco
70
0.70
NA
550
10. 5
5.5
KA
NA
lignite
NA
PAC
C Nuchar S-A
65-85
NA
385-415
1400-1800
4-6
3-4
4-8
2.2-2.5
SCO
NOTE: Properties defined by manufacturer's specification literature.
NA: Not Available
20
-------
TABLE 5. PROPERTIES OF ADSORPTION RESINS
PROPERTIES
Aobcrsorb
XE-340
Anberaorb
XE-347
ABbcrsorb
XE-348
AoberllU
XAD-4
Appearance
Total Surface Area
(HI BET Bcthod MVg»)
Bulk Density (Ibs/cu ft)
Particle Density (g/cm>)
dig displacement)
Skeletal Density (g/ca>)
dig displacement
Pore Volume (g/ca1)
Particle Size
(U.S. Sieve Series
Crush Strength
(kg/Particle)
Ash Content (%)
Average Particle Dlaoctcr (m)
True Met Density In Distilled
Hater (go/I)
Average Pore Dlaacter (An-jst
black, spherical
non-dust Ir.g
400
37
0.92
1.34
0.34
30-50
CT 3.0
LT O.S
black, spherical
non-dusting
350
43
1.05
1.85
0.41
ZC-50
CT 3.0
LT O.S
black, splicrical
non-dusting
500
37
0.91
1.95
0.58
20-50
1.0
LT 0.5
hard, hydratcd
opaqu* beads
725
44
1.08
JO-vO
0.30-0.45
1.02
40
NOTE: Properties dctlnjil by Manufacturer's specif leal Ions.
CT: Greater Than
IT: I«ss Than
-------
Activated sludge process investigations Included conventional activated
sludge, conventional activated sli.dge with the addicion of powdered activated
carbon (PAC) to the aeration chamber, and activated sludge seeded with Pheno-
bac*, a commercial mutant bacteria product. All biological oyatems were
operated on a continuous flow basis using either raw wastewater or wascewater
pretreated in different ways. Attempts were made to acclimate the systems to
the wastewater beins Investigated prior to assessing process performance.
For activated sludge studies, either 350 ml Swisher reactors (Figure 2)
or one liter reactors (Figure 3) were used. The smaller reactors generally
were used to screen the feasibility of aerobic biological treatmeMt or when
available wastewater quantities were limited, necessitating reduced through-
puts while still operating at the desired hydraulic and organic loading rates
and retention times. They also facilitated examination of the extent of
stripping of volatile organlcs due to aeration because two Swisher units, one
operated with activated sludge biomass and one containing only wastewater,
could easily be operated in parallel. It should be noted that several prob-
lems were experienced with the Swisher reactors:
o Because flow rates were small, the quantity of effluent produced
over a reasonable period of time greatly United effluent analytical
testing options.
o Close control of the air.fd liquor suspended solids (MLSS) was
difficult because the quantity of sampla required for MLSS analysis
would severly deplete the volune of sludge remaining in the reactor.
Despite these problems, the reactor? were relatively easy to maintain and
useful for screening the feasibility of aerobic biological treatment.
Larger reactors were used during the PAC addition studies, when longer
duration runs were intended, when larger quantities of treated effluent were
required for priority pollutant analyses, and when better mixed liquor sus-
pended solids (MLSS) control was desired.
Two sizes of trickling filter apparatus were used: a 4.9 cm diameter by
58 cm long plexiglass column, and a 2.54 cm by 122 cm glass column. Each
ccntalned a rock media and was operated in a downflow mode. Although this
configuration facilitated Influent dosing, maintaining an aerobic environment
proved to be difficult. The filter discharged to a clarifying apparatus from
which settled sludge was recycled back to the filter or wasted. Be ause of
difficulties associated with their operation and poor performance, studies
using a trickling filter were terminated and are not discussed further herein.
Anaerobic biological treatment was Investigated using a heated, packed
bed anaerobic filter operated in an upflow morie. Figure 4 schematically
illustrates the reactor and gas collection system. Operating criteria are
discussed in Section 4 where process perfoirjnce is reviewed.
For the aercbic systems, seed sludge initially was obtained from munici-
pal wastewater treatment facilities. To acclimate the biomass, the processes
22
-------
33cm
Outltt
Figure 2. Davis-Svisher Feactcr
23
-------
Influent-
Effluint
Sludge Wotting
Figure 3. One Liter Biological Reactor.
-------
6AC
Column
l"lD*
(Glot«)
K)
01
ANAEROBIC
COLUMN
(Clatl)
Pump
dipih
B.rl
SoddU
Pocking
Figure A. CAC/Anaerobic Filter Schematic.
-------
were operated on • municipal wastewater feed for ocoe period of tine and then
were gradually converted to the fesdwater being used in che Investigation.
When necessary, feedvater oooposition was Kodlfied by pH adjustment (with
dilute phosphoric or sulfuric acid) and nutrieut addition.
The anaerobic filter initially was filled one-half full wlrh sludge from
a veil-operated municipal wastewatcr treatment sludge anaerobic digester and
operated for eight days on raw ouniclpal sewage before converting to ground-
water pretreated by CAC adsorption. Feed later was converted to raw contam-
inated grouudwater. Operating details are given In Section 4.
Filtration
When vastevat£rs contained suspended solids that were expected to Inter-
fere with the operation of the primary treatment process (e.g., plugging of
CAC adsorption column), granular media filtration was used for pretreacsont.
Columns of various sizes were loaded with white sand which patsed a No. 40
sieve (<0.0165 in. particle size) and operated In a gravity dovnflow sode.
Qy.onacion
evaluation of ozonation was conducted on a batch basis. The process was
used as the primary treatment process and as a pretreatment technology.
Figure 5 Illustrates a schematic of the ozonatlon assembly. A Welsbach Model
T-408 laboratory scale ozone generator was operated under the following condi-
tions:
o ozone production using air feed
o ozone g»s flow rate - 2 1/oln
o ozone dose - approximately 2 g/hr (generator operating at 90 volts)
o glass reactor vessel with fritted glass dlffusers
o batch volume - 7.5 to IS 1.
Studies using contaminated groundwater began after preliminary studies with
distilled water to assure good nixing and ozone transfer. Ozone measurements
were made according to Standard Methods (4) using the lodometric Method.
Stripping'
Air Stripping —
Air stripping techniques included diffused aeration as well as stripping
under mechanical nixing and quiescent conditions in open containers. Air
stripping generally «-as Investigated whenever stripping was judged to be one
of several avenue? of contaminant removal associated ulth a particular treat-
ment technology; for example, during diffused aeration activated sludge
treatment or ozonation. In these situations, either a stripping reactor was
26
-------
OZONE
GAS
Woltr SomplM
eir to
purgt
from wottr
Kl Solution tor
63 tntropmtnt
Figure 5. Schematic of Ozonation Assembly .
-------
operated In parallel with Che primary process being investigated (for activat-
ed sludge a parallel Swisher or larger reactor was operated) or the primary
process reactor was operated solely to investigate stripping (the ozonatlon
reactor was operated with air rather than ozone).
Steam Stripping —
A packed column, continuous flow apparatus was used to evaluate steam
stripping; Figure o illustrates a schematic of the system. Although numerous
variables affect sysfes performance, the primary operation parameters inves-
tigated were feed flow race and overhead flow rate. Maintenance of steady
state conditions proved to be difficult and the apparatus was not capable of
operating in the desired overhead to teed flow ratio range of 0.02 to O.OS.
Operating and performance details are discussed In Section 4.
28
-------
FEED
PREHEATER
FIBER GLASS!
WRAPPED
STEAM
FEED •
GLASS
COLUMN
VOLATILE
ORGAN ICS
.T.OW
METER
IN
VENTED
ASPIRATOR
BOTTLE
(CONOENSATE
RECEiVER)
VALVE
8
FLOW METER
VALVE
ffl
PUMP
ROUND
BOTTOM
HEATER
S MM BERL
SADDLE PACKING
FIBERGLASS
WRAPPED
-
SIPHON
PUMP
45/54 T FITTING
AND ALUMINUM
SUPPORT
SCREEN
REBOILER
(5L)
BOTTOMS —-
ANT I-
SIPHON PUMP
VALVE
_IN
COOLING
WATER
i=OUT
TEMPERATURE
CONTROLLER
Figure 6. Continuous Flow, Packed Column Steam Stripping Apparatus.
29
-------
SECTION 4
STUDIES USING CONTAMINATED GROUNDWATER FROM THE OTT/STORY SITE
BACKGROUND
AC Che Ott/Story site in North Muskegon, Michigan, groundwater has been
contaminated by the disposal and poorly controlled storage of chemical produc-
tion wastes by previous owners of a chemical production facility. The present
owner, Cordova Chemical Company, cooperated with the State of Michigan in
carrying out efforts to remove contamination sources; characterize site
geohydrology, groundwater quality, and contaminant plume migration; and iden-
tify and evaluate remedial action options for management of contaminated
groundwater. Results of the study described herein were nade available to the
Michigan Department of Natural Resources (DNR) as they evolved to assist that
agency in its evaluations. Subsequently, the Ott/Story site was declared a
Superfund site by the U.S. Environmental Protection Agency.
Most of the technology evaluations discussed herein were performed using
composite samples obtained from two wells in the contamination plume: wells
OW9 and W17d. Groundwater composition differed substantially at the two well
locations as Illustrated by the data contained in Table 6. Croundwater
composition at other points in the plume also varied widely from that reported
in Table 6. lable 7 presents a summary of contaminated groundwater compo-
sition data measured at various points in the plume.
Identified organic compounds at the measured concentrations listed in
Table 6 do not account for the measured TOC concentrations.
Chroma tographs of several GC'/rlS analyses for priority pollutants in
samples from studies using composite groundwater from wells OW9 and Wl?d were
examined to investigate the presence of non-priority organlcs. Several
phenolic, aniline, phthalate, and organic acid compounds were irdicated.
However, because extraction procedures used for priority pollutant analyses
are not suitable for extracting all non-priority organic compounds, other
organics present cannot be identified and thus, a comprehensive estimate of
constituents comprising groundwater TOC cannot be prepared. The legal and
health effects significance of non-priority pollutants in raw groundwater, and
in partially treated groundwater are unknown.
TECHNOLOGY EVALUATIONS
As described in Section 2 and summarized in Table 1, the following
technologies were evaluated using groundwater from the Ott/Story site:
30
-------
TABLE 6. COMPARISON OF ORGANIC POLLUTANT ANALYSIS
OF RAW GROUNDWATER FROM WELLS OW9 AND
W17d (mg/1)*
Parameter
Vinyl Chloride (P)
Mechylene Chloride (P)
1.1-Dlchloroethylene (P)
1,1-Dlchloroe thane (P)
Chloroform (P)
1.2-Dlchloroe thane (P)
1,1,1-Trlchloroethane (P)
2-E thoxyp ropane
Tricliloroethylene (P)
Benzene (P)
Perchloroethylene (P)
Toluene (P)
Chlorobenzene (P)
2-Chlorophenol (P)
Phenol (P)
Benzyl Alcohol
Benzole Acid
Hexanic Acid
Cresol
Methyl Propyl Phenols
1 ,2-Dlchlorobenzene (P)
Aniline
Methyl Aniline
n,n-Dicethyl Aniline
2-Chloroaniline
Camphor
Benzonitrile
Substituted Benzenes
1,4-Dichlorobenzene (P)
TOC
Well
OW9
2.23
0.60
0.18
1.03
0.87
103.
0.13
0.18
0.01
0.12
0.01
0.2
-------
TABLE 7. OTT/STORY SITE CROONDWATER GENERAL CHARACTERIZATION
Parameter
Composition Range**
pH
BOD
COD
TOC
NH3-N
Organic N
Chloride
Conductivity
TDS
Volatile Organics:
Vinyl chloride*
Methylene chloride*
1,1-Diehloroethylene*
1,1-Dlchloroethane*
1,2-Dichloroethane*
Benzene*
1.1,2-Trichlorotf thane*
1.1,2,2-Tetrachloroethar.c*
Toluene*
Ethyl benzene*
Chlorobenzene*
Tvtchlorofluoronethane*
Chloroform
Trichloroethylene
Tetrachloroethylene
Acid Extractable Organics:
o-Chlorophenol*
Phenol*
o-sec-Butylphenol***
p-Isobutylanisol*** or
p-Acetonylanlsol***
p-sec-Butylphenol***
p-2-oxo-n-Butylpheaol
m-Aceconylanisol***
Isopropylphenol***
1-Ethylpropylphenol
Dimethylphenol*
Benzole acid
10-12
300 - 1600 og/1
5400 - 8300 mg/1
200 - 2100 mg/1
50 - 200 mg/1
110 mg/1
500 - 4100 ng/1
18,060 umhos/cm
12.000 mg/1
140 - 32.500
<5 - 6570
60 - 19.850
<5 - 14.280
0.350 - 111 eg/1
6 - 7800
<5 - 790
<5 - 1590
<5 - 5850
<5 - 470
<5 - 140
<5 - 18
1400
40
110
<3 - 20
<3 - 33
<3 - 83
<3 - 86
<3 - 48
<3 - 1357
<3 - 1546
<3 - 8
<3
<3
<3 - 12.311
(Continued)
32
-------
TABLE 7. (continued)
Parameter Composition Range**
Methylphenol 40
Methylethylphenol 20
Methylpropylphenol 210
3.4-D-Methylphenol 160
Base Extractable Organics;
Dicblorobenzene* <10 - 172
Dlmethyianiline <10 • 17,000
m-Ethylaailine <10 - 76^0
1,2,4-Trlchloiobenzene* <10 - 28
Naphthalene* <10 - 66
Methylnai-hthalere <10 - 290
Camphor <10 - 7571
Chloroaniline <10 - 86
Benzylaoine or o-Toluidine <10 - 471
Phenanthr-jne* or
Anthrare-.u:* <10 - fc70
Methylanillne 310
*A ptloricy pollutant
**A11 concentrations in ug/1 except as noted
***Structures not validated by actual compound
33
-------
o adsorption - granular activated carbon
- powdered activated carbon resins
o biological treatment - activated sludge
anaerobic filter
o ozonation
o stripping - air
- steam
Efforts commenced with preliminary investigations focused on pretreatment by
neutralization, chemical coagulation, and precipitation; methods of sol-
ids/liquid separation; and volatility concerns. Following this, batch studies
of Individual unit processes were undertaken. Sequential batch studies and
continuous flow studies of one unit process and trains of processes then were
undertaken.
In the following sub-sections, results are organized and reported pri-
marily by unit process. However, because numeious process train evaluations
were made, it is most useful to report certain results by process train rather
than by individual unit process.
Preliminary Studies
Results of preliminary batch investigations in the area of chtmical
neutralization, coagulation, and precipitation first are summarized below.
1. Small amounts of fine sedicent and silt were present in the ground-
water samples. This material did not have associated measurable TC
or TOC content. It settled slowly under quiescent as well as
stirred conditions. Attempts to coagulate this sediment with ferric
chloride and several polymers produced no effect either in app^ar-
ance or in TOC reduction in the supernatant liquid.
2. Samples in contact with 5 gm/1 powdered activated carbon for five
minutes filtered more readily and appeared clear and colorless, even
when TOC removals were less than IS percent.
3. Samples stored for two days ir. full, sealed glass flasks showed TOC
reductions of 0 t- 7 percent.
4. Reductions in TC and TOC concentrations in raw groundwater by separ-
ation using vacuum filtration, gravity filtration, and centrifuglr.,-
all were very slight. Vacuum filtration was selected for use ii»
subsequent studies (when solid/liquid separation of this type was
necessary) because it was the most convenient technique and did not
appear to induce significant stripping of volatile organics.
5. Studies on volatilization of organics were conducted for periods of
48 hours using open quiescent, stirred, air sparged, and closed
34
-------
containers at the prevailing groundwater pH of about 10 and adjusted
pH values of 7.5 and 6.0 with the following results:
a. less than 7 percent TOC reductions in closed containers,
b. 20 to 25 percent TOC loss from quiescent samples at all pH
values and from stirred and sparged samples at pH 10.
c. 40 percent TOC loss from stirred and sparged samples at pH
values of 6.0 and 7.5.
The preliminary investigations led to the conclusion that careful sample
handling was necessary to minimize experimental error due to loss of volatile
organics and for protection of laboratory personnel. All work was conducted
in fume hoods using glass containers to the maximum extent possible.
Air and Steam Stripping
Since chlorinated hydrocarbons were of key concern at the Ott/Story site,
technologies found useful in the treatment of similar constituents in drinking
waters seemed appropriate for use in this research. Techniques lor the
removal of halogenated hydrocarbons from drinking water previously have been
summarized (5). Ott/Story site groundwater differed qualitatively from
drinking water in that it contained chlorinated hydrocarbons, aromatics and
simple organic acids analogous to drinking water "chlorinated hydrocarbon
precursors", and uncharacterlzed high molecular weight "non-priority" pollu-
tants.
Simple aeration and steam stripping are considered viable approaches for
volatile halogenated hydrocarbon removal in drinking water (5). Since nost of
the priority pollutants at the Ott/Story site were associated with the vola-
tile fraction (Tables 6 and 7), air stripping would provide the simplest
approach for removal of bulk hazardous constituents. Steam stripping with
reflux would provide a greater degree of volatile halogenated hydrocarbon
removal and also allow for recovery and concentration of such materials in the
condensed overhead stream thus abating a potential air pollution problem.
Air Stripping—
Air stripping experiments were carried out in a series of 2.5 1 Plexiglas
reactors which were equipped with porous airstones to sparge the groundwater.
Data shown on Table 8 illustrate that all volatile priority pollutants were
reduced to non-detectable levels after air sparging. In addition, activated
carbon treatment of the air sparged effluent resulted in virtually complete
removal of the remaining base neutral and acid fraction priority pollutants.
Therefore, it was concluded that technology similar to that suggested by EPA
for drinking water applications (5), would be applicable to removal of prior-
ity pollutants from the Ott/Storage groundwater. However, a significant
organic residual as measured by TOC remained after air stripping and the air
stripping/carbon sorption batch treatment sequences.
35
-------
TABLE 8. REMOVAL OF GROUSDWATER ORGANIC
POLLUTANTS BY AIR STRIPPING
Concentration in:
Type
V
V
V
V
V
V
V
V
V
V
V
V
V
B/N
B/N
Compound
Methylene
Chloride
1 , l-Dichlo-
roethane
1,1-Dichlo-
roethylene
Chloroform
1,2-Dichlo-
roethane
1,1,1-Trl-
chloroethane
Trichloro-
ethylene
Benzene
Perchloro-
ethylene
Toluene
Chloro-
benzene
Ethylbenzene
1,1,2-Tri-
chloroethane
Dlchloro-
benzene
Methylani-
line
Raw
Ground-
water
0.07
1.6
1.0
2.0
14
0.28
0.05
5.3
0.19
3.6
0.18
0.02
0.05
0.05
0.24
(Continued)
36
Air
Spar-
ging
Effl1
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.53
Sparge
and
Carbon
Sorp-
tlon
Effl2
0.50*
HD
ND
"ND
0.01
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
-------
TABLE 8. (contl.iued)
Concentration in:
Type
B/N
B/N
B/N
B/N
B/N
A
A
A
A
A
A
A
Compound
Ethylanllene
Trlchloro-
benzene
Naphthalene
Dimethyl-
aniline
Camphor
Chloiophcnol
Phenol
Methylphenol
Methylethyl-
phenol
Methylpro-
pylphenol
3,4-Diaiethyl-
phenol
Benzole Acid
TOC
Rav
Ground-
watar
3.8
0.01
0.01
15.0
3.9
0.03
0.01
0.04
0.02
0.28
C.12
0.30
720
Air
Spar-
ging
1
Effl1
0.60
ND
ND
0.61
0.47
0.01
0.01
0.03
0.02
0.28
0.14
0.02
641
Sparge
and
Carbon
Sorp-
tion
Effl2
ND
ND
ND
0.08
0.01
ND
ND
ND
ND
ND
ND
ND
Footnotes:
'Air sparge for 48 hr at pH 6.0
2Air sparge for 48 hours at pH 6.0 followed by 2 hr
contact with SO g/1 dose of FS 300 carbon
V » Volatile Priority Pollutant
B/N - Base neutral extracted fraction
A • Acid extracted fraction
ND - Not detected (detection limit - 0.01 ng/1)
* •> Possible saeple contamination during extraction
37
-------
Stean Stripping—
Figure 6 illustrates the continuous flow, packed coluon steam stripping
apparatus. Independent operating variables were reboiler temperature and
overhead:feed flow ratio. The apparatus was operated at feed stream flow
rates of 40 to 80 ml/min, overhead (condensate) flow rates of 3.5 to 9.2
ml/min (overhead:feed flow ratios of 0.064 to 0.14), Influent TOC concen-
trations of 480 to 610 mg/1, and time durations of 1 to 4 hours after estab-
lishing steady-state operation within the available operational controls.
Figure 7 presents a summary of results on a TOC basis. Average TOC in
the stripper bottoms ranged from 300 to 400 mg/1 and vas virtually independent
of overhead to feed ratio. This represented an approximate 34 percent overall
TOC concentration from feed stream to stripper bottoms.
Steam stripping resulted in a concentrated overhead product which, at an
overhead:feed ratio of 5 percent, had a TOC of about 4,000 mg/1. This repre-
sents a concentration of organics by a factor of 10 to 13 tines and flow
reduction to 5 percent of the feed value. While the laboratory-scale dis-
tillation column experienced stability problems at overhead:feed ratio of less
than 6.4 percent, commercial scale units can operate at much lower ratios,
thus providing for even further enrichment of the volatile priority pollutant
and TOC fractions.
Conclusions regarding steam stripping are summarized below:
o Stream stripping is an energy intensive operation with marginal
environmental advantages over simple aeration.
o Stean stripping removed a greater fraction of TOC from the bulk flow
than air stripping. Air sparging resulted in about 11 percent
volatilization of TOC from the bulk flow with removal of virtually
all volatile priority pollutants. Steam stripping resulted in
removal of about 34 percent of TOC from the bulk flow with recovery
of these organics in a more concentrated overhead product.
o The environmental health and regulatory significance of materials
remaining in air and steam stripper bottoms are unknown. The
environmental health and regulatory significance of air emissions of
small quantities of volatile priority pollutants also are unclear.
Air stripping appears to be an acceptable pretreatsent technique if
air emissions are judged insignificant. Aerated groundwater aay
require further treatment for oxygen demand, trace organic, and
heavy metal removal before discharge.
o As will be shown below, while air stripping was considered an excel-
lent choice for the fourth site studied (Clear., N.Y.), it did not
appear to completely resolve problems at the Ott/Story site.
38
-------
u
o
4000-r
3000-•
2000- •
1000* -
OVERHEAD CONOENSATE
• STRIPPER BOTTOMS
A ***
•+•
•+•
-H
006 008 010 O.iZ OJ4
OVERHEAD--FEED RATIO
Fi'jure 7. Continuous Steam Stripping of Contaminated Groundwater
at Study Site .
39
-------
Adsorption
Isotherm Studies-
Table 9 summarizes isothena studies completed and study conditions for
each. Tests were performed using raw groundwater (Including composites and
Individual samples from veils OU9 and U17d) and groundwater pretreaeod by
aeration, ozooatlon, biological treatment, and various sorbents. Variables
Investigated included sorbent, sorbent dose, pK, and contact time. Results
are presented in Tables 10 through 17; isotherm data *re plotted according to
the Freundlich equation on Figures 8 through IS.
Prior to conducting tne studies listed in Table 9. preliminary tests were
performed which indicated that:
o Adsorption equilibrium is achieved after about 2 hours and 4 hours
of contact for carbons and resins, respectively.
o Sorbents did not contribute significant concentrations of soluble
organics to adsorption study filtrates. In studies in which distil-
led water was contacted with powdered FS-300 carbon and XE-347
re&in, filtrate TOCs were 0 and 21 mg/1, respectively.
Examination of the isotherm batch contact study -jata resulting fron use
of raw composite groundwater indicates the following:
o Freundlich isotherms for all sorbents are steeply sloping straight
lines when plotted on a logarithmic scale.
o Generally, carbons had slightly greater adsorption capacities than
the resins at all pH values studied. In addition, carbons were
capable of achieving slightly lower effluent TOC concentrations than
were the resins.
o With regard to TOC removal efficiencies, carbons all performed about
the same (See Table 10). Greater removals were observed at pH 10
and pH 4 than at pH 7.
o XE-347 performed slightly better th&n the other resins, with slight-
ly better TOC removal at pH 4. IP part, the poor wetting of XE-340
may have affected its performance.
o No sorbent was capable ot achieving greater than 62 percent TCC
removal even at sorbent doses as high as 100 g/3.
These results show that sorption alone is not capable ot achieving high
degrees of TOC removal from raw groundwater. This, In part, could be expected
based on the presence of numerous soluble, low molecular weight organic
compounds in the groundwater.
Similar, although less extensive. Isotherm studies were completed using
composite groundwater pretreated by aeration, ozonatlon plus activated sludge,
40
-------
TABLE 9. SUMMARY OF ISOTHERM STUDIES
fortenl HI
m CMOUII* ymnna] n HO (.11
>.
••
MX t.ll
1.
4.
OC M t.M
I.
4.
OOMI
ta'll
0.1. 1, 90,
0.9, 9, W,
O.I, 1. M,
O.I, 1, 90,
O.I, 1, 10,
O.I, 1, JO.
0.9. 1, 90,
0.1. 9. SO.
0.1. 1. 10.
r«niKt l>n i.l
TIM TOT
Ik 1 In/ II
100
100
100
109
100
too
ICO
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It- 110 g.« O.I. 1. 9O. lot 1 (Ot
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II II
II II
II II
pr«trt*l«4 by monatloB
C
•
OKUII* IOW/III Ml
nHfokLc Illltr
n 100
lei o.i. I, u, loo i
9*1
II
11
-------
TABLE 9. (Continued)
*»t«ll»
Coxxull* IO»/»IMI
PI.II..IKJ br IK
cilUm lOjorpllon
Covuiu (on/HiTdi
pulrrtlvd br IE-MI
Kiln rtioiplloi
Om CtounOnKr
on GroundMUr
piitrMiM br •ctimx
HI 74 Ccoun4Mt«r
Ciiton Colt
S..IMOI pH
IS nolcl 9.7
n no 9.t
7.0
HOC 9.4
7.
tfcchir S-» 9.4
7.0
ra too 9.1
ra no 1.1
n no «.9
9.4
7.
HC 9.9
9.4
7.
Huctur 8-« 9.9
9.1
7.
•ma - studr rand
<-.,
90
9, 10, 90. 100
1, 10, SO, 100
1, 10. 10. IOO
9. 10. 10. 100
9. 10. 90, 100
9. 10, HI, 100
1
9
,
0.9. 9. 90
0.1. 1. 10
9
0.9, 9, 90
0.9, 9, SO
9
0.9, 9. 90
0.9, S, 90
tlm>
ConlKt
Tin iBlllil
(be) in/11
1 411
4 MX
4 IUIO
4 tin
4 1190
4 lira
4 IUO
a.t. i, i. i KM?
1 1077
0.1.1, 1, 4 110
1 1M>
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0.1.1. 1. 4 MO
i in
1 110
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i in
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11-117 I
19 II
It 11 UD-4 9.4
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It II If-liO 9.4
It II 7
It II lt-147 9.1
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-
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lit
rim*
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IS
II
19
II
-------
TABLE 9. (Continued)
llulmKr C«iKoa «etl»«t« • ilodi Condi limn «»«la l»rt>«ciU • 'iwtt fciKUIaM
Conl«cl (fluid CocUet
Sortmt t*
-------
TABLE 10. CARBON SORPTION ISOTHERM DATA USING RAH COMPOSITE GROUNMATER
DOSE
SORDFNT M(g/l
BLANK 0
FS 300 0.5
5.0
50.0
£. 100.0
*-
HOC 0.5
5.0
50.0
100.0
GAC 30 0.5
5.0
50.0
100.0
Nuchar S-A
0.0
1.0
5.0
15.0
30.0
50.0
TOC
C (ng/1)
pll 9.85 pll 7.0 pll 4.0
603 641 690
504 557 593
388 441 421
266 326 326
248
574 635 641
457 502 526
306 362 367
271
541 575 599
370 454 417
271 326 308
230
pH 10.1
736
653
558
491
452
429
pH 9.65
99
215
337
JS5
29
146
297
332
62
233
332
373
83
178
245
284
307
TOC SORBED LOADING
x (nq/l) X/H (ag/g)
pll 7.0 pll 4.0 pll 9.85 pll 7.0 pll 4.0 p
84 97 198 168 194
200 269 43.0 40.0 53.6
315 364 6.74 C.JO 7.28
3.55
6 49 58.0 12.0 98.0
13* 164 29.2 27.8 32.8
279 223 5.94 5.58 6.46
3.32
66 91 124 13? 182
187 273 46.6 37.4 54.6
315 382 6.64 6.30 7.64
3.73
83.0
35.6
16..'
9.47
6.14
TOC
H 10.0
16.4
35.7
55.9
S8.9
4.8
24.2
49.3
55.1
10.3
38.6
55.1
61.9
11.
24.
33.
38.
41.
REMOVAL
pH 7.0 pH 4.0
13.1 14.1
31.7 39.0
49.1 52.8
0.9 7.1
21.7 23.8
43.5 46.8
10.3 13.2
29.2 39.6
49.1 55.4
-------
TABLE 11. RESIN SORPTICN ISOTHERM DATA USING RAH COHTOSITE GROUKDHATER
SORBBiT
BLANK
XAD-4
XE-347
XE-340
DOSE
Hlg/1)
0
0.5
S.O
50.0
100.0
0.5
S.O
50.0
100.0
O.S
S.O
50.0
100.0
pH 10.0
715
654
593
487
448
598
570
404
331
670
620
537
537
TOC
C log/I)
pll 7.0
567
.'17
455
388
-
528
438
393
-
534
494
449
-
pH 4.0
551
511
433
36S
-
517
399
264
-
534
483
376
-
pH 10.0
61
122
228
267
117
145
311
384
45
95
178
178
TOC SOK3ED
x (ng/g)
pH 7.0 pH 4.0
50
112
179
-
39
129
275
-
33
73
118
-
40
118
185
-
34
152
287
-
17
68
175
-
LOADING
X/N («g/ll
pH 10.0 pH 7.0
122
24.4
4.56
2.67
234
29.0
6.32
3.84
90.0
19.0
3.5C
1.78
100
22.4
3.6
-
78
25.8
5.5
-
66
14.6
2.4
-
1
pH 4.0 pH 10.0
80
23.6
3.7
-
68
30.4
5.7
-
34
13.6
3.5
-
8.5
17.1
31.9
37.3
16.4
20.3
43.5
53.7
6.3
13.3
24.9
24.9
TOC REMOVAL
(U
pH 7.0 pH 4.0
8.8
19.8
31.6
6.9
22.8
48.5
5.8
12.9
20.8
7.3
21.4
33.6
6.2
27.6
52.1
3.1
12.3
31.8
-------
TABLE 12. ISOTHERM DATA FOB COMPOSITE GRODNDKATER
PRETREATED BY OZOHATIOH OB AERATION
SAMPLE SOSBENT
Raw GrovBdraler
Grouodwater
after oxoaatlon
faroundvater
after aeration
Fretreated by rs 300
Osonatloo
ZU> 4
XE-340
XE-347
Pretreated by FS 300
Aeration (2.5 hr
aeration)
ZM> 4
SORBEWT
DOSE
8(9/1)
0
0.5
5
50
106
0.5
5
50
106
0.5
5
50
106
0.5
5
50
106
0
0.5
5
50
106
0.5
5
50
106
FINAL
TOC
Cf(«g/l)
1050
1020
1020
985
900
615
633
573
984
942
682
852
970
ISO
920
888
985
930
830
730
940
876
754
609
560
925
912
8JO
767
toe
SOBBED
Z(B9/1)
85
170
352
412
1
43
103
133
15
35
65
97
0
55
155
255
64
186
331
380
15
28
90
17J
SORBEHT
LOADING
X/H (119/9)
170
34
7.0
3.9
2
8.6
2.1
1.2
30
7
1.3
0.9
0
11
3.1
2.4
128
37.2
6.6
3.6
30
5.6
1.8
1.6
OVERALL
TOC
REMOVAL (%)•
14.3
22.4
39.7
45.4
fi.3
10.3
16.0
18.9
7.6
9.5
12.4
15.4
6.2
11.4
21.0
30.5
16.6
28.2
42.0
16.7
11.9
13.1
19.0
27.0
• Calculated on the basis of rav groundvater TOC and final TOC after adsorption.
-------
TABLE 13. ISOTHERM DATA FOR COHPOSITE GROTODWATER PRETREATED
ANAEROBIC FILTER BY OZONATXON/ACTIVATS) SLUDGE AND DPFLOH
SORBEMT DOSE
M(g/U
FINAL TOC
C£
-------
TABLE 14. TOC REMOVAL DURING SEQUENTIAL
BATCH STUDIES OF SORPTION AND
AIR STRIPPING
STUDIES
Results
Sorbenc
Loading
(mg/g)
Aeration followed
by Carbon Sorption
Carbon Sorption
followed by
Aeration
Carbon Scrption
followed by
Resin Sorption
Condlcicnn
of Study
Aerate 48 hr at
initially adjust-
ed pR 6.0; 5 g/1
dose HOC carbon
for 2.5 hr at
pH 6.0
50 g/1 dose FS 300
carbcri for 3.5 hr
at initially ad-
Justed pH 6.5;
aerate 48 hr at
pH 8.0 to 8.75
50 g/1 dose HOC
carbon for 3.5 hr
at initially -id-
Justed pH 6.5;
50 g/1 dose XE-
347 resin for 1
hr at pH 8.0
Initial TOC: 650
TOC after aeration:
346. TOC after
sorption: 199
First seen TOC
removal: 47Z
Overall TOC
removal: 69Z
29.4
Initial TOC: 600
TOC after sorption:
259 (C ). TOC affer
aeration: 189
First step TOC
removal: 57%
Overall TOC
removal: 68Z
6.82
Initial TOC: 600
TOC after carbon
sorption: 268 (Cf)
TOC after resin
sorption: 237 fCf)
First step TOC
removal: S2Z
Overall TOC
removal: 60Z
First step: 6.24
Second step: 1.02
48
-------
TABLE IS. REMOVAL OF TOC AND AND SPECIFIC ORGANIC POLLUTANTS5
DURING SEQUENTIAL BATCH STUDIES
Pollutant Concentration (mg/1)
Raw
Compound Uastewater
TOC
Methylene
Chloride
1 , 1-Dichlo-
roethane
1 , 1-Div-hlo-
roethylene
Chloroform
1,2-Dlchlo-
roethane
1,1,1-Tri-
chloroechane
Tricholoro-
ethylene
Benzene
Perchloro-
ethylene
Toluene
Chloro-
benzene
Ethylbenzene
1,1,2-Tri-
chloroethane
638
0.06
1.2
0.06
1.4
111
0.12
0.04
7.8
0.11
2.6
0.14
0.01
0.16
Study A
1
Resin Carbon Raw
Sorption Sorption Wastevater
Effluent Effluent
455
ND
ND
ND
ND
0.23
ND
ND
0.17
ND
ND
ND
ND
ND
332
ND
ND
ND
ND
0.01
ND
ND
0.01
ND
ND
ND
ND
ND
(Continued)
49
720
0.07
1.6
1.0
2.0
14*
0.28
0.05
5.3
0.19
3.6
0.18
0.02
0.05
Study B2
Aeration Aeration
Effluent Carbon
Sorption
Effluent
641 301
ND 0.503
ND ND
ND ND
ND ND
ND 0.01
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
-------
TABLE IS. (continued)
Pollutant Concentration (ag/1)
Rav
Compound Wastevater
Dlchloro- 0.09
benzene
Methylanl- 0.31
line
Ethylanllinc 3.3
Trlchloro- 0.01
benzene
Naphthalene 0.01
Dimethyl- 17.0
aniline
Camphor 4 . 0
Chlorophenol 0.02
Phenol 0.01
Methylphenol 0.04
Methylethyl- 0.02
phenol
Methylpro- 0.21
pylphenol
3,4-Dlnethyl- 0.16
pnenol
Benzole Acid 0.17
Sorption Capacity
(mg/g)
TOC Removal (7.)
Study A1
Study B2
Resin Carbon Raw Aeration
Sorption Sorption Wastevater Effluent
Effluent Effluent
ND
ND
ND
ND
ND
0.25
0.04
ND
ND
ND
ND
ND
ND
ND
7.32
29
HD
ND
ND
ND
ND
ND
ND
SD
ND
ND
ND
ND
ND
0.18*
6.12
276
0.05 ND
0.24 0.531*
3.8 0.60
0.01 ND
0.01 ND
15.0 0.61
3.9 0.47
0.03 0.01
0.01 0.01
0.04 0.03
0.02 O.G2
0.28 0.28
0.12 0.14
0.30 0.02
Aeration
Carbon
Sorption
Effluent
ND
ND
ND
ND
ND
0.08
0.01
ND
ND
ND
ND
ND
ND
ND
6.8
536
50
-------
NOTES
1 Study A Involved resin sorptlon followed by carbon sorption. Conditions
during the study stages were:
Sorbent: XE-347 FS 300
Dose: 25 g/1 SO g/1
Contact Time: 4 hr 2 hr
Wastewater pH: 9.7 9.7
2 Study B Involved treatment by aeration followed by carbon sorption.
Aeration accomplished by sparging for 48 hr at pH 6; aeration effluent
contacted with FS 300 carbon at SO g/1 dose for 2 hr.
3 Sample believed to be contaminated vith methylene chloride
** Questionable results
5 Specific organic analyses focused on priority pollutants. A few non-
priority compounds were detected by the procedure and were quantified;
however, no effort was made to identify all non-priority pollutants.
6 Rumoval attributable only to the unit process
KD - Not Detected at detection limit of 0.0' tng/1
51
-------
TABLE 16. ISOTHERM SORPTION DATA ON CROUNDWATER FROM WELLS OW9 AMD W17d
saaan
turn
n MO
Hjctar «-»
me
it-no
11-117
UD-I
0061
ii/n
0
,
10
M
in
s
10
so
100
J
10
so
100
100
100
100
on c
TOC
C((»g/ll II
pH t 1
IIM
Itl7
ISII
117)
III*
It It
Itlt
lilt
nai
I70t
It7l
DM
IIM
117}
IMI
1171
pi 7.0
1110
ItW
mi
1111
IIM
Itlt
1547
IIM
lilt
not
Itl7
1117
1117
mi
III)
ISO!
PH t.l
171
Ul
M7
70S
Ml
KM
Ul
til
IIS
III
411
190
I4S
SI*
IIS
IOU04MUI
III
TOC SOHUD
•g/ll «/!l(«g/fl>
DH 7.O
110
111
M?
Ml
101
HI
in
MM
IIS
171
101
til
It*
til
117
pll t.l pH 7.0
ll.t 11.0
M.I 11. I
10.
7.
10.
10.
1.
••
11.
II.
1.
S.
ll.t
t.t
IB.l
17.1
I.I
1.0
:i.o
li.l
1.1
t.l
I.I l.t
t.l I.I
I.I 1.1
TOC RDUVM.
D* t.l
t.s
It.*
M.O
M.7
11.0
11.0
IS 1
II.*
t.l
7.*
11.7
li.l
11.0
n.:
11.0
DH 7.O
ll.t
It.*
ll.t
U.I
11.0
lt.0
M.t
11.1
t.l
t.»
11.1
11.1
IS.*
li.l
17.1
cost
l/ll HI
0
O.I
S
M
O.S
S
so
O.S
I
so
s
s
s
e, tag/i
t.i p
110
ISO
I*
10
IIS
10
II
17*
11
*
Ul
100
117
•171 <
TOC
1
* 7.O pi
in
IM
M
10
111
II
II
IT*
M
10
It?
in
ISO
40WXM4I
.,"'
TOC MOD
Il>g/ll I/m«g/|l
1 t.l PH 7.0
•0
IM
110
ts
IM
117
SI
II*
III
It
H
SI
•1
ItO
110
M
IM
101
11
III
II*
SI
M
TO
Pll t.l
IM
M.*
I.I
in
M.O
1.1
IM
I7.t
4.1
t.*
t.O
10.*
at 7.0
III
M.O
1.1
111
ll.t
I.I
M.O
M.I
1.1
10.*
1.0
11.0
TOC tOOOL
III
pll t.l
14.*
M.I
ts.t
li.l
li.l
M.I
li.l
11.7
M.I
li.l
11.0
11.0
dl 7.0
17.1
M.I
W.I
11.1
li.l
M.I
It.l
• 1.1
M.I
li.l
ll.t
11.*
III Cutiet Tin • I tr
111 Coottct TIM - I br
-------
TABLE 17. ISOTHERM SORPTIOH DATA FOR OW9 AND
U17d CROONDWATERS PRETREATED BY
ACTIVATED SLUDGE
TOC
TOC
Sample
Capacity
C,(ag/l) Adsorbed X/M(mg/g)
1 X(og/l)
TOC
Removal
(Z)
Blank - OW9 Croundwater 1077
pretreated by activated
sludge
OU9 Groundwater 744
pretreated by activated
sludge
333
66.6
30.9
Blank - W17d Groundwater
pretreated by activated
sludge
W17d Croundwater
pretreated by activated
sludge
99
12
87
17.4
87.9
Sorbent: FS 300 Carbon
Dose: 5 g/1
Contact Time: 1 hr
53
-------
1000-
100-
0
CARBONS
O FS 300
A HOC
Q GAC 30
O NUCHAR S-A
ElO-
RESINS
O XAO-4
A XE - 347
D XE - 340 100
A XE -347(PH 9.7)
RESINS Q pH 10
CARBONS Q pH 9 85
EXCEPT NUCHAR 0 10.1
200 300 900 600 100
residual TOC (Cf) rmj/l
200 SCO 900 BOO
Fig\ir« 8. Adsorption Isoth«ras, Raw Composite Groundwater, pH 10.C .
54
-------
1000-
RESINS
O XAO-4
A XE-347
Q XE-340
100-
10-
CARBONS
O FS 300
A HOC
O GAC 30
• FS300 (pH6.5;
A HOC (pH 6.5)
RESINS Q pH = 7 0
CARBONS B pH = 7.0
!OO 200 SCO 500 80O 100
residual TOC (Cf) mg/l
200 300
500
300
Figure 9. Adsorption Isotherns, Raw composite Groundwater, pH 7.0.
55
-------
Rums ($ pH 4
Carbon
-------
WOO -I
100-
o
o
Q OZONE«-FS 300 CARBON
• AERATION (2.5 HR.)+FS 300 CARBON
A OZONE+XAD 4 RESIN
A AERATION fXAD 4 RESIN
O OZONE + XE-340
O OZONE + XE-347
V AERATION (48 HRS) + FS 3OO CARBON
10-
I
100
1000
Figure 11.
Residual TOC(Cf)mq/l
Adsorption Isotherms, Cooposite Grour.cwater Pretreated by
Ozonation or Aeration.
57
-------
100-
10'
o
o
Anaerobic
Filttr
Effluent
+ FS300
Carbon
Oxont/AS Effluent
•»• FS 300 Carbon
10
100
Residual TOC (Cf) mq/l
1000
Figure 12. Adsorption Isotheras, Composite Groundwater Pretreated by
Ozonation/Activated Sludge and Upflow Anaerobic Filter.
58
-------
O FS 300
A Nuchor SA
O HOC
• XE-340
A XE-347
Q XAD-4
40-
30-
* 20H
1
^ 10-
- 9-
? 8-
S 7-
o
O
6-
5-
2-
I-
pH 9.4
40
30
20-
10
9
8
7
6
5
4-
3-
2-
1000 2000 300O
Figure 13. Adsorption Isotherms, Hell OW9.
PH7.0
1000 2000
RMidual TOC (Cf) mg/l
3000
-------
100-
w
10-
u
o
O FS 300
A Muchar SA
Q HOC
• XE-340
A XE-347
I XAD-4
T—
!0
100
R»«idual TOC (Cf)mg/l
Figure 14. Adsorption Isotherms, Well W17d, pH 7.0.
60
-------
O FS 300
A Nuehor SA
D HOC
• XE-340
A XE-347
• XAD-4
100
10-
o
o
7 10
IOO 1000
Residual TOC (Cf )
Figure 15. Adsorption Isothetas, Well 17d, pH 9.4.
61
-------
and anaerobic treatment by upflow filter. Results are presented in Figures 11
and 12 and Tables 12 and 13. Operating conditions for these pretreatment
processes are described in subsequent sections pertaining to tbe unit process.
Results of these studies indicate that, in general, Freundlich isotherms
are steeply sloping straight lines when plotted on a logarithmic scale.
However, pretreatment by ozonation plus activated sludge (0?/AS) resulted in
an isotherm which changes slope sharply indicating the presence of adsorbates
with different sorption characteristics. Except in the case of ozona-
tion/activated sludge pretreatment, sorption characteristics were not affected
by the different pretreatment methods even though initial TOC concentrations
varied considerably as a result of pretreatment. Except for the ozona-
tion/activated sludge pretreatment case, sorbentu were not capable of achiev-
ing effluent TOC concentrations of less than 290 mg/1 or TOC removal effi-
ciencies of greater than 51 percent at sorbent doses of up to 100 g/1. Where
comparisons were made between carbon and resin sorbents, carbon always had
better sorption capability.
Figure 16 summarizes the best activated carbon and resin sorption results
from the aeration and ozonation pretreatment studies.
Sequential/Batch Studies
Prior to undertaking continuous flow column adsorption studies, the
following batch sequences were examined: (1) air stripping followed by carbon
sorption, (2) carbon sorption followed by air stripping, and (3) carbon
sorption followed by resin sorption. Uastewater TOC concentration following
these treatments remained high (greater than 189 mg/1).
Results of the sequential experiments raised questions with regard Co the
nature and composition of the residual TOC. Therefore, it was deemed neces-
sary to perform some specific compound analyses to gain better insight. To
extend the investigation, additional separate carbon and resin sorption and
sequential air sparging-carbon sorption batch experiments were conducted. Raw
wastewater and treated waters were analyzed for organic priority pollutants.
Results of these studies are summarized below:
o Carbon adsorption reduced clmost all organic priority pollutants to less
than GC/MS detection limits. An exception was benzole acid, which would
not be expected to be removed by carbon. TOC removal capacity compared
favorably with earlier results.
o Resin sorption proved to be only slightly less effective tlian carbon
sorotion. TOC removal capacity compared favorably with earlier results.
Most organic priority pollutants were reduced to below detection limits.
All were reduced by at least 98 percent, however, several still i-smained
at 170 to 250 mg/1.
o Carbon treatment of air stripped groundwater generally resulted in re-
duction to less than detection limits for the organic priority pollutants
62
-------
200-
100-
X 30-
10-
o
o
E 5-
3-
I
Colgon FS300 Activated Carbon
Well Composite'
O Ozone Prttreflted
{TOC)0«985mg/l
Well Compotit«<
O Aerated Prttrtattd
(TOC)0 =940 ma/I
I
W4I No. OW-9 only:
• Aerated ftetreated
100 200 300
1000
Residual TOC(Cf) mg/l
XAD-4 Resin
O Ozone Pretreated
(TOOo-985 mg/l
O Aerated Pretreoted
(TOC)0 =940 ma,/1
1000
Figure 16- Adsorption Isotharas: Comparison of the Best Carbon and
the Bast Resin (Aerated or Ozone Pretreated).
63
-------
remaining after stripping. All were reduced by more than 98 percent.
TOC adsorption capacity was similar to previous tests.
o Despite good removals of organic priority pollutants, a significant
residual TOC (301-455 mg/1) was measured in all treated samples. This
residual represents unidentified, non-priority organic pollutants.
Specific organics breaking through most consistently were 1,2-dichloro-
ethane, benzene, dimethylaniline and camphor.
o Preaeratlon followed by granular activated carbon eorption appeared to be
effective for the Ott/Story Site removing volatile priority pollutants,
and virtually all acid and base/neutral substances. Residual TOC values
remained high, however.
A limited number of isotherm adsorption studies were conducted using OW9
and Wl7d groundwater samples individually (See Table 16 and Figures 13, 16,
and 15). The isotherms again are steeply sloping lines. Results indicate
that:
i
o pH adjustment made very little difference in TOC adsorption with the
exception that XAD-4 performed slightly better at pH 9.4.
o Carbons performed much better than resins for both waste streams and at
both pH values.
o The three carbons performed similarly with FS-300 and Nuchar SA having
slightly greater equilibrium adsorption capabilities.
o At the maximum dose tested, TOC removals from OW9 and W17d groundwater
were 39 percent and 95 percent respectively and resulting TOCs were about
1100 mg/1 and 10 mg/1, respectively.
As a result of the Isotherm and sequential batch studies, it generally
was concluded that adsorption is a unit process applicable to the situation at
the Ott/Story Site. Carbon adsorption alone and resin sorption to a lesser
extent were capable of achieving high degrees of organic priority pollutant
removals. However, the adsorption process alone was not capable of reducing
groundwater TOC concentrations to levels typically acceptable for direct
discharge co a surface water.
Based upon the steeply sloping straight line of the adsorption isotherms,
1C is assumed that carbon capacity is not fully used; thus, residual organics
are not sorbable. Pretreatment by various unit processes with adsorption used
as a polishing process provided additional TOC removal. Results of continuous
flow process trains employing adsorption in the pretreatment as well as
polishing modes are presented later.
Continuous Flow Studies
Table 18 provides a comprehensive listing and summary of continuous flow
adsorption studies. For this series of studies, adsorption was used as the
primary treatment process, for precreatment, and for post-treatment. When
64
-------
TABLE 18. CONTINUOUS FLOW ADSORPTION STUDIES
CONTINUOUS HYDRAULIC LOADING
FLOH STUDY RATE
NUMBER SORBENT HASTENATER C/B2.Bln) COLUMNS
1 FS 300 raw composite (OW9 and H17d) 81 1
2
3
«
2 PS 300 rnw composite (OH9 and H17d) 81 1
2
3
4
3 FS 300 raw coaposlte (OH9 an! H17d) 81 1
2
3
4 FS 300 raw coaposlte (OH9 and W17d) 81 1
2
3
S XE-347 raw coaposlte (OH9 and H17d) 81 1
2
3
6 XE-347 raw coaposlte (OH9 end H17d) 81 1
2
3
CUMULATIVE
SORBENT
DEPTH
lo)
90
180
270
360
90
180
270
360
90
ISO
270
90
180
270
48.3
104.2
156.3
SO
100
ISO
EMPTY BED
CONTACT
TIME
(Bin)
11
a
33
44
11
22
33
44
11
22
33
11
22
33
6
13
20
6
13
20
BED
VOLUMES
PROCESSED
351
175
117
88
248
124
83
62
503
2S1
168
£25
312
208
121
56
38
106
S3
35
COMMENTS
See Figure 17
See Figure 19
See Figures 18, 20 and
Table 19| activated
sludge used as post-
treatoent
See Figures 18 and JO)
activated sludge used I
post-treatrent
See Figure 19
(Continued)
-------
TABLE 18. (Continued)
CONTINUOUS HYDRAULIC LOADING
TltW STUDY KATE
NUMBLR SORBEHT HASTEHATER Activated
•ludge used (or pest*
treataent
See Figure 20; Activated
sludge used for post-
treatMnt
Activated sludge used for
post-treatsent
See Figure 20; activated
sludge used for post-
treataent after adsorption
See Figure 20
See Figure 20
(Continued)
-------
TABLE 18. (Continued)
(.am mmus
FLOW STUDY
NUMBER SORBDTT
NASTEHATER
HYDRAULIC LOADING CUMULATIVE DUTY BED BED
RATE SORBENT COKTACT VOLUMES
tl/«2.«ln) COLUMNS DEPTH TIME PROCESSED
(cm) (Bin)
CONKEHTS
It re 300 OH9 Croundvalor
15 rs JOO OH9 Groiuidw«ter
2.B2-4.ll
2.77-1.75
60
97
1«0
196
B2
63
See Flour* 22| Activated
sludge used for post-
treataent
6e« n«ura »f Activated
ui*d for post-
16 FS 300 raw coaposlto (0» and H17d) 1.96-3.92 1 68.S 203 65
17 PS 300 rav coaposllo (OU9 and H17d) 2.S6-4.S3
IB PS 300 H17d groundvater
81.6
78. i
85
167
J3$
II
21
34
122
S6
Option aiworeblc fllUr
Iben activated sludge
used for post-trealaent
Upflov anaerobic filter
then activated sludge
used for poat-treataent
See Figure 22
19 rs 300 OH9 gruind«ater
3.55-4.44
69
182
23
See Figure 22) upflow
anaerobic filter used for
poit-treatBent
-------
used as the primary process, three or four carbon columns were arranged in
series and operated ft a constant hydraulic loading rate of about 2 gpm/ft2.
(See Table 2 for SI conversion). When used is part of a continuous process
train, a single carbo" column operated at a loading rate dictated by the other
unit operations was used. Based upon results of the isotherm studies, FS-300
granular activated carbon (GAC) and XE-347 carbonaceous resin were selected as
sorbents to be further investigated throughout the continuous flow study
phase.
During the course* of conducting the studies listed on Table 18, it was
noted that TOC rapidly broke through the adsorption system; this is illus-
trated on Figures 17, 18, and 19. Effluent TOC values of less than about 100
ng/1 could be achieved only within the first three to ten bed volunes of
loading. Removal efficiency decreased rapidly to less than SO percent.
Therefore, with influent TOC ranging from 600 to 1000 mg/1 (In the composite
of OU9 and W17d), an effluent TOC of 300 to JCO mg/1 was typical after a short
period of operation.
Figure 17 illustrates the progression of TOC breakthrough through a
system wich four columns in series. These results are typical of Che adsorp-
tion process In general and of other studies conducted during investigations
at the Otc/Story site.
Figures 19, 20, and 21 illustrate TOC adsorption by CAC and XE-3&7 resin
for selected studies under different conditions as summarized in Table 18.
These data indicate that:
o Operating at empty bed contact time? (EBCT) from 10 to 226 mln had no
consistent effect on the adsorption of TCC. This also is demonstrated by
the results of studies wich two columns In series (Figure 19) and three
columns in series (Figure 20, 2P. In these studies, Che equilibrium
weight of TOC adsorbed per unit veighc of carbon in the first column
(having an EBCT of 11 mln) of the series was equivalent to the adsorption
of the entire bed (having an EBCT of 22 mln for two columns and 33 min
for three columns) at any point along the carbon loading curve.
o The adsorption capacity of XE-347 was lower than that of FS-300 under
similar study conditions. Adsorption capacity of FS-300 and typical TOC
breakthrough characteristics were not affected by procreating Che waste-
water vlth ozone.
o Carbon adsorption capacity appeared to be slightly improved by pre-
treating with a process crain consisting of ozonacion followed by acti-
vated sludge. However, Improvement in capacity was only slightly better
than demonstrated by activated sludge pretreatment alone.
Despite the inability to maintain high levels of TOC removal, GAC adsorp-
tion demonstrated substantial organic priority pollutant removals. As indi-
cated on Table 19, even when loaded a I 111 ing TOC/g carbon, FS-300 continued
to sustain high levels (83 percent or better; of priority pollutants removal
at TOC removals of only 35 percent and effluent TOC concentrations of greater
68
-------
80 100
Volumt TrtaUd (liters)
COLUMN I EFFLUENT - D
COLUMN 2 EFFLUENT - O
COLUMN 3 EFFLUENT - A
COLUMN 4 EFFLUENT - *
Influent TOC*SOO tolOOOmg/l
.io
Figure 19. Typical TOC Performance (Breakthrough) Curve.
-------
Study 3
Study 4
lOOO-i
800-
600-
01
E
o
o
400-
200-1
virgin carbon cddad
adeorp. unit offl.
act. tludgt unit I «ffl.
act. «ludo« unit 2 effl.
0
10
SO
DURATION (daya)
Ficjure 18. Performance of GAC/Activated Sludge Process.
I
40
I
50
£0
-------
100
-------
200-
O
O
o
Study
3
3
6
S
II
12
13
(Sat Tabio
Conditions
Column I
Columns 1,233
Column I
Column* 1,2 E 3
Column I
Column I
Column I
Column I
Column I
.'8 )
ESCT (rein) Procesi Troln
11333 GAC
II a 33 GAC
II a 33 GAC
11 & 33 GAC
213-226 GAC
2I3-22S GAC
433 Gic-r.s Prefreoimant
143 Ozons/Activafsd Sludgu PrafreoJmsnt
10 Activated Sludga Proirca'mont
300 400 600
TOC Loading (ng TOC/g GAC)
eoo
Figure 20. TOC Adsorption by Granular Activated Carbon,
-------
Study Conditions
A
0
0
X
V
e
125-
O
**
3 IOO-
9
0
o
H 75-
o
E
SO-
ti
o
TJ
0 25-
(J
O
H
O
*
a
(Sc«
o
*n«M
Jgx>
1
50
3
4 Colunm 1
4 Co'umna 1 3
JJ ""
8
9
II —
12
13
Tobi« 18 )
*
V^
Cffi
o cP0^ »
'. " gOclK
»
*o
r
v X
X x
1 1 1
100 130 200
ESCT(rr.!n)
33
1 1
33
20
222
21 3
4C3
143
10
9
o o°o
o
A «>
> Q
I 1
25O 300
Process Troin
PAC
GAC
GAG
K:«i,i XE-347
GAC/AS
e AC/AS
O^on-J/GAC/AS
02cn;/GAC/AS c
AS/OAC c i
O
p
^
«*
0
i i i i i i r
J50 400 450 500 550 600 65O
TOC Loading (mg TOC/gGAC)
Figure 21. TOC Adsorption by Granular Activated Carbon.
-------
TABLE 19. TOG AND PRIORITY POLLUTANT DATA FOR
GRANULAR ACTIVATED CARBON/ACTIVATED
SLUDGE P30CESS TRAIN
Collected on
Day 2*
Raw GAG
Ground- Effl.
water
Collect on
Days 9 and 10*
Collected on
Day 17*
Raw CAC AS GAG AS
Ground- Effl. Effl. Effl. Effl.
water
Average carbon loading
when sample collected
(mg TOC/g Carbon)
Parameter (mg/1):
TOC
Total Cyanide
CNA
Total Phenol
Hethylene chloride
1.1-Dichloroethene
1,1-Dichloroethane
Trans-1,2-dichloro-
19
111
233
637 380 929 604 90 770 183
NA NA 0.11 0.21 0.23 0.23 0.20
NA NA <0.05 <0.05 <0.05 <0.05 <0.05
NA NA Id <0.16 <0.10 <0.10 <0.10
2.1 0.029 14 0.01 ND 0.16 ND
1.6 ND 0.06 0.01 ND ND ND
2.4 ND 0.17 0.02 ND ND ND
ethane
Chloroform
1 ,2-Dlchloroe thane
1,1,1 -Trichloroe thane
Trichloroethylene
Benzene
1,1 ,2-Trichlorce thane
0.06
9.8
72
7.6
0.06
1.2
0.11
ND
ND
ND
ND
ND
ND
ND
0.04
0.70
25
0.39
0.03
1.5
0.07
ND
0.06
1.4
C.04
ND
0.02
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.05
ND
CT
ND
ND
ND
ND
ND
ND
ND
ND
(Continued)
74
-------
TABLE 19. (Continued)
Collected on
Perchloroethylene
Toluene
Chlorobenzene
Phenol
2-Chlorophenol
2 , 4-Dlchlorophenol
1 ,2-Dichlorobenzene
Dibutyl phthalate
Day 2*
Raw
Ground-
water
0.49
2.3
0.23
0.025
0.040
0.010
0.085
ND
Collect
on
Days 9 and 10*
CAC
Effl.
ND
ND
ND
ND
ND
ND
ND
ND
Raw
Ground-
water
1.9
0.97
0.29
0.028
0.036
0.010
0.077
ND
GAC
Effl.
ND
0.05
ND
ND
ND
ND
ND
ND
Collected on
Day 17*
AS
Effl.
ND
ND
ND
ND
ND
ND
ND
0.05
GAC
Effl.
ND
0.01
ND
ND
ND
ND
ND
ND
AS
Effl.
ND
ND
ND
ND
ND
ND
ND
ND
NA - Not Analyzed
ND - Not Detected
No other priority pollutants detected at 0.01 ag/1 detection limit
* - Refers to Adsorption Study No.3 as illustrated on Figure 18
75
-------
than 600 mg/1. At 71 bed volumes, representing a loading of 233 mg TOC/g
carbon, Che only priority pollutants detected in the GAC effluent were meth-
ylene chloride, 1, 2-dichloroethane, and toluene.
The significant differences in the adsorption characteristics of ground-
waters from two different wells at the Ott/Story site are illustrated in
Figure 22. Organic materials In W17d, as measured by TOC concentration, were
more readily sorbed by FS 300 than was TOC in W17d. Moreover, the sorption
characteristics of OW9 were comparable to the OW9/W17d composite, Indicating
that some compounds in either OW9 or U17d are preferentially adsorbed to the
exclusion of other compounds despite the fact that sufficient opportunities
for adsorption still exist.
During the course of the continuous flow adsorption studies, results were
found to correlate well with isotherm data previously presented. Moreover,
priority pollutant removals were in agreement with other published data sum-
marized in an earlier project report (1).
Biological Treatment Activated Sludge
A number of activated sludge trearabillty studies were conducted. These
included use of a biomass acclimated to raw contaminated groundwater, sludge
seeded with Phonobac®, addition of powdered activated carbon to the activated
sludge aeration chamber, and pretreatinent of the groundwater by carbon adsorp-
tion or ozonation. Table 20 summarizes the operating conditions and results
of these studies. Time was allowed between studies for acclimation to new
study conditions.
Several attempts were made to acclimate an activated sludge culture to
the raw groundwater. Mixed liquor, obtained from the preaeration basin of the
Muskegon County wastewater treatment plant, was fed a mixture of raw municipal
wastewater and groundwater. Cver the course of about nine weeks, the fraction
of groundwater in the feed was increased from 0 to 100 percent in approxi-
mately 10 percent increments. Hydraulic retention time in the aeration
chamber was about seven hours and mixed liquor suspended solids averaged about
3300 mg/1 during this oeriod. To assure adequate nutrients, phosphorus, as
phosphoric acid, was added to provide a TOC:N:P ratio of about 100:17:5.
Hydrochloric acid or sodium hydroxide were used to keep the pH in the range
6.5 - 7. Daily pH adjustment was needed due to the high alkalinity and
buffering capacity of the water.
Attempts to develop an acclimated culture were minimally successful. As
system influent contained a greater fraction of groundwater, slignt loading
fluctuations resulted in growth of a poorly settling, light colored, fila-
mentous biomass. As shown on Figure 23, once the systems were acclimated to
the extent possible, TOC removal ranged from about 35 to 60 percent. EL fluent
TOC concentrations ranged from 176 to 472 mg/1 as shown in Figure 26. How-
ever, subsequent studies indicated that the strippirg effect of diffused
aeration could account for about two-thirds of the removal. Performance (TOC
removal) at retention times of 4.3 to 8.3 hr and about 16 hr did not appear to
be significantly different.
76
-------
100-
90-
80-
o
o
60-
40-
o
o
30-
20-i
10-
Theorjtlcol
100% Adsorption
O
O Row Ccmpcslto - Typical Adsorption
O OW9 flroua^^a««r - Study Mo. 14
© OVV9 grcundwatcf - Study Na. 15
© OV»9 cfocndaoJer - Study f»o. !3
A U'lTd groundti-aJar - SJudy No. iS
(Ssa Tobl« ia i
50
100 150 200 250
TOC Loading (mg TOC/gGAC)
330
400
Fir re 22. TOC .Adsorption by GAG for Composite Groundwater and Individual Wells.
-------
TABLE 20. STUDIES OF THE ACTIVATED SLUDGE PROCESS
00
STUDY
NO. NASTEHATER
OPERATING I
TUITIONS REMOVAL
REACTOR HUT Ihr)
TYR AVER
RANGE 1
TOC LOADING
ia/1 Lb/lOOOcu.ft./day
AVER
raw coBposlte IOW and V17d)
raw capos Ite (CMS and H17dl
raw coipoalte (OH<> and H176)
raw coaposlte 1(*W and H17dl
raw coapoilte (CH9 and H17dl
raw coBpoille (OH9 and HI7dl
raw coBposlle (OU9 and H17d)
raw composite t*M9 and HlTdl
raw cacposlle (OH9 and H17d)
11 raw enapoilte IOW« and H17dl
.1 law coaposltc IOU9 and HI7dl
R
R
R
S
S
S
R
R 1
R 1
R
g
.6
.1
.6
.O
.1
.9
.1
.6
.1
.1
.7
1.0-9.8
1.6-4.4
4.0-6.2
5.0-7.9
4.1-1.0
1.1-14.6
6.9-10.4
10.8-18.2
11.9-17.8
1.4-S.2
1.1-9.7
651
641
622
511
SIB
541
614
611
664
645
517
AVER
209
217
208
115
127
157
114
62
62
228
156
RANGE
114-101
115-280
114-216
96-205
80-205
45-279
94-145
52-79
51-76
184-266
74-625
No.
of
Data
Points
20
6
8
26
22
11
6
7
8
5
28
TOC
REMOVAL COMMENTS
AVER RANGE
50
47
17
54
51
41
46
61
61
42
48
40-57
42-57
10-40
15-69
41-48
25-«4
42-49
52-60
59-70
15-49 Trace elcBenti added
17-58 Ptwnobac*) culture
12 coapoaUa (I1W9 and W17J) GAC
pmtreatoil
8 4.1
1.0-5.6
212
68
4i-ei
7
90
78-95 Cffluent froa GAC Study I
11 coapoall* ((W9 and HI7d) GAC
prut totted
8 4.8
1.4-5.6
201
69
17-94
7
90
77-100 tffluent from GAC Study I
14 coopoilte (OU9 and H17d) GAC
pretreatcd
S 5.0
4.5-6.0
192
119
41-156
6
88
72-98 Effluent froa GAC Study I
IS cuBDOSlt* (OM9 and NI7dl GAC
pretreatcd
R 6.2
5.6-6.4
489
124
61-185
10
87
61-100 effluent fro» GAC Stud.' I
16 conposlte (OH9 and N17d) GAC
prelrcatcd
R 6.1
5.1-7.1
489
128
55-196
10
85
61-100 effluent fro» GAC Study S
17 coaposlta (OH9 and HI7d) GAC
pntreated
IB coaposlt* (OH9 and N17dl QIC
prelrnted
PAC to aeration checbor
R 8.0 7.0-9.1 647 122 97-141 7 71 65-79 Effluent fra GAC Study 1
R 8.1 7.1-10.4 647 120 94-117 7 71 65-74 Effluent froa GAC Study 1,
PAC reddual In aeration
chamber
(Continued)
-------
TABLE 20. (Continued)
STUDY
MO.
19
20
21
22
21
24
25
1*
27
28
29
10
OPERATING
CONDITIONS
REACTOR HUT (hi)
NASTUUTER
roepoilte (OH9 and N17d) GAC
pretreated
composite (OM9 and HI7dl GAC
prelreated
composite (cm and N17J) GAC
pretreaturt
composite (UN9 and NI7d) GAC
prctrealed
composite 10W and HI7dl reiln
pret reated
composite (OH9 and N17d) realn
pretreated
composite (OH9 and HI7dl resin
prttt 1*04 1 od
composite (OHO and HI7d) realn
pret leafed
composite (OH* and HI7d) GAC
pretreated
conposlte (ON9 and H17d) GAC
pretreated
composite (DHt and N17d) GAC
pretreated
cwpoalte tom and WI74) GAC
pretreated
TYPE
R
R
R
R
R
R
R
R
R
R
R
AVER
5.9
16.7
6.0
6.6
4.0
8.8
9.5
7.7
8.6
8.6
8.9
RANGE
1.6-11.1
9.8-21.9
5.6-8.4
S. 1-7.0
1.9, 4.0
7.1,10.4
8.8,11.5
6.2-9.8
7.6-8.9
7.6-9.8
6.O-11.9
•9./I
AVER
170
402
465
450
520
520
518
119
179
490
542
TOC LOADING
ll>/!OOOcu.fl./day
AVER RANGE
92
41
107
107
197
87
IJLfl
lou
86
ei
66
85
98
19-121
14-72
66-146
66-146
152-241
81-91
47-119
11-116
5«-89
10-121
57-161
No.
of
Data
Polnti
11
20
14
8
2
2
1
10
9
2]
21
REMOVAL
TOC REMOVAL GUNNIMO
AVER RANGE
87 62-100
76 58-99
69 Sl-BI
59 51-72
79 74. 82
80 71. 81
fiB S4 7*1
72 SI, 79
91 47-100
81 76-88
76 S4-IOO
82 59-100
Effluent froa
Effluent fro*
Effluent fro*
Effluent froa
Effluent froa
Effluent froa
Effluent froa
Effluent froa
Effluent froo
Effluent froa
Elfluanl froa
GAC Study 4
GAC Study 4
GAC Study 4
GAC Study 4
rmln Study S
mln Study S
reiln Study 6
reiln Study 6
GAC Study 7
GAC Study 7
GAC Study 8
GAC Study 9
used for GAC Study 12
(Continued!
-------
TABLE 20. (Continued)
00
o
OrOO.TIHG COOITIWS
STUDY
NO.
11
J]
11
11
IS
M
18
19
«0
11
41
41
44
41
46
REACTOR IIRT Ihrl
MAST OUTER
commit* (OM and UI7d) GAC
pratrcated
napoille IOH9 and MI7d)
coipatlU (MM and NI7d)
oBono pretreated
CMpoalte IOM9 and H17dl
oione prelrealed
composite (OH9 and H17dl
oiono and dAC prslreatcd
rapoMte IUM9 and Wild)
utoiM prelrcaced
17 composite
One and UAr pratrcated
coapoalte «CN9 and UI7d)
GAC and U»F protreatid
OH9 o/roundvater
OW9 groii'.dvaler
OM erouMvater
OH9 groundvaler TAG pretreated
OM9 groumlvaler CMC pretrealed
HI7d troundna'nr
H17d ^loundvattr
H17d «rounrt»«t«r
TY1-E
R
R
8
8
8
two ai
R
B
s
s
R
R
8
8
B
AVER
T.9
17.2
21.7
3.7
Id NI7d)
9.7
9.8
12.1
11.1
10.4
10.4
5.9
10.4
14.1
TOC LOADING
RANC.C «g/l
AVER
7.1-9.8
11.9-20.8
16.2-29.2
4.9-7.1
8.1-12.8
7.2-12.8
10.8-11.9
11.2-1S.4
9.1-11.6
8.8-11.9
S.B-6.t
9.7-11. J
I2.1-1M
762
M9
777
Kjn
Sfu
RAI
OOI
96
69
im
i jf
1907
1992
1761
1171
181
221
228
Lb/luOOcu.rt./dar
AVM RANGE
119
»7
17
206
111
1 Jl
5«»
• VI
IS
11
• 1 1
Jl 1
216
'215
182
191
47
12
2S
110-202
51-72
14-77
102-104
M*fM
•JOT
m*!JUk
••TOO
1-11
2-16
)atJ»i1f A
afVWIO
191-299
179-279
7S-100
151-117
12-64
2C-40
16-14
No.
of
Data
Point!
24
a
21
IS
17
10
IS
9
11
7
11
IS
S
RHOVAL
TOC RBPVAL UJ8UIIIJ
AVER RANGE
76
68
47
48
17
40
SO
56
72
SS
SI
SI
42
49-98
61-81
11-66
10-fl
9I»?A
af I**O
•JWtlA
JV^SV
0-79
0-100
Ir.B*
> >•
10-67
1S-65
14-02
11-81
18-72
11-7S
22-S7
Effluent fm CAC Study 10
PAC «d4ted to Mratlon
cbaatMr
ft ft .. ant fv^tB AaU* Clmfci 11
•ilium iron UN*. DiiMy •*
«- A •••••*• BlIltA^ dtf f llBAtlt
ML%l*4l\VU •lUBy* *• IktimK
Cfflueot froa CAC Study 16
Effluent fn» CAC Study 17
Bfflwhl rna CAC Study 14
Ef flora t froa GAC Study IS
R - I liter reactor unit
S - 250 ml Sulaher unit
CAC - Granular Activated Carhon
UAf - Uuflo* Anaerobic Filler
PAC - Pondered Actlvalrd Cailion
-------
100-
90-
00-
70-
3 eo-
4C— *
•^
? 30-
«, °
t- E
^ 40-
U
0
30-
20-
10-
V Phenobac Study No. 11 57HRT
O AS Study NOB. 182 4SHRT
+ AS Study No. 3 46HRT
Vr AS Study No. 4 60KRT
O AS Study No. 9 16 1 HRT
X AS Study No. 6 15.6 HST
(Sea Tobl« 20 )
0
^^^-^^ X >V
*^^- <\ ?,* * *
.*> C)4*- -'V "* ,
^X X ^--^ v 7 * ft
o^W ,v v^ v ey ° «
x * ^ ^^*S*^ e °
v ^v ^>~^^-Z___ 0 0
••*•; *-^TTV%^-^—
V
* +
i I | | | II I | 1 1 1 1 j 1 1
20 40 60 80 100 120 140 160 180 200 220 220 240 260 230 300
Figure 23.
Ibs TOCL/ 1000 ft3 doy
Activated Sludge TOC Removals.
-------
500
400-
300-
OD
K> ^
"o
£
o
O
2CO-
100 •<
Ronga of Data for
Phcnobac System
20
I
40
Study No. II
Study i\'oi. I a 2
Study No. 3
Study No. 4
Study No. 5
Study No. 6
60 100 120 140 160
Ibc TOCL/ !000ft 3
—I—
180
—I—
Z CO
Z20
—I—
240
260 280
300
—I
320
Ficjure 24. Activated Sludge Effluent TOC Concentrations.
-------
A conoerclally available bacterial culcure adapted for hydrocarbon degra-
dation also was studied. Phenobac* provided by Folybac Corporation was se-
lected because of its reported suitability for the type of wastewater occur-
ring at Che Ott/Story site. The culture was prepared according to Polybac's
instructions. Both the Fhenobaco system and the conventional activated sludge
system were fed only rav groundwater. Operating conditions are shown in Table
20. The Phenobac® system achieved an average TOC reduction of about 48
percent with a range of 37-58 percent. There was no observed advantage to the
use of Phenobac* based on effluent TOC.
Adsorption Pretreatment/Biologieal Treatment Process Trains
Adsorption/Activated Sludge System —
As a result of marginal performance by both conventional activated sludge
and Phenobac* systems using raw groundwater, additional activated sludge
studies were conducted using groundwater pretreated by (a) sorption using
granular activated carbon (GAC), (b) organic resin, (c) chemical oxidation via
ozone, (d) CAC and ozone, (e) CAC and upflow anaerobic filter processing and
(f) the addition of powdered activated carbon (PAC) to the aeration chamber.
Studies 12 through 22 and 27 through 31 summarized in Table 20, were
conducted to study the influence of GAC pretreatnent on activated sludge
performance. Although a variety of operating conditions were investigated,
results were found to be fairly consistent. Figure 25 illustrates performance
of the activated sludge process in the GAC/activated sludge process train
during studies 15 through 22 and 31. Figure 26 summarizes daily results;
these data are judged to be representative of all studies. To normalize.
variations in wastewater composition from run to run, influent loading to the
GAC/activated sludge process train is presented on tho. basic of cumulative TOC
loading per unit weight of activated carbon.
It was found that GAC pretreatment of raw 5roundwater permitted develop-
ment of a culture of aerobic organisms capable of further treating GAC efflu-
ent.' In excess of 95 percent TOC removal was achieved by this process train
during the period when the GAC process accounted for at least 30 percent of
the TOC renoval. After this initial period, process train performance de-
clined as GAC performance declined. These data indicate that some fraction of
TOC began to leak through the system after a short period of operation. The
fraction of TOC which leaked through the GAC system was not toxic to activated
sludge (AS). These organics did not appear to be removed or reduced either
biologically or by the air stripping associated with AS aeration.
Operation of the AS portion of this process train at hydraulic retention
times (HRTs) ranging from 4 to 16 hr, with or without the addition of powdered
activated carbon to the biological reactor, or with or vithout Phenobac®
addition seemed to have little impact on process train performance (based upon
TOC removal). Overall system performance was maintained at 75 to 85 percent
TOC removal (effluent TOC of 100 to 185 mg/1) for about 21 days. This repre-
sents processing of more than 110 BVs for the GAC process and 46 retention
times for the AS process. Results of these studies are illustrated in Figure
27. Although not illustrated in the figure, Phenobac* subsequently was added
83
-------
Converted from 3 column
to tingle column 6AC
- Ntw OAC column
placed on lint
Sludgt Efflutnb
10
40 60
Duration (dayt)
70
60
90
Figure 25. Performance of GAC/Activated Sludge Process Train.
-------
8 lo
lOO-i
90-
80-
70-
!""
5 so-
.«
30-
20-
10-
O Removal by 6AC/A8 system
A Incremental TOC removal by AS
a Removal by GAC alone
20 40 60 60 100 120 140 160 160 200 220 240 260 280 300 520
mg TOO loaded/ gram of carbon
Figure 26. TOC Removal by GAC/Activated Sludge Process Train.
-------
Specialized sampling events (Sao Toble 21 ,)
lOOO-i
eoo-
600-
U
o
400-
200-
GAC
Influent
., . O
GAC
Effluent
o — *
Stripper Effluent-^
PAC Effluent
9-'5 '«
IB 19 22 23 24 25 26 29 30 10-1
Date (I960)
Figure 27. Performance of GAC and Activated Sludge Process Modifications.
-------
to one of the reactors during the course of this run. There was no difference
in TOC removal between the Phenobac® reactor (operated at 6 hr HRT) and the
conventional AS reactor (operated at 16 hr and 6 hr HRTs). As TOC leakage
from the GAC process increased, biological process removal performance dimin-
ished. Conventional AS and Phenobac* reactor effluents contained about 200
mg/1 TOC when this phase of the study was completed. Visual observations and
typical mixed liquor analyses (MLSS and MLVSS) suggest that the biological
systems could survive in and utilize GAC pretreated groundwater even after GAC
performance had declined to about 10 percent TOC removal.
During the entire two month duration of this phase of study, TOC removal
by the GAC/AS process train varied from 100 to 74 percent. Effluent TOC could
be maintained at levels less than 100 mg/1 only for short periods of time and
only when GAC performance was at Its peak. Limited analyses, however, suggest
that high levels of organic priority pollutant removals can be attained even
with effluent TOC concentrations of 100 to 200 mg/1. Table 21 presents
results of GC/MS analyses for organic priority pollutants conducted at several
times during the operation of the GAC/AS process train. Almost all organic
priority pollutants detected in raw groundwater were removed consistently to
less than the level of detection (0.01 mg/1) by the process train. One
consistent feature of these data and previous GC/MS analyses from batch carbon
adsorption studies is the early leakage of 1, 2-dichloroethane. A few other
compounds (benzene, mcthylene chloride, and toulene) also were detected to
have broken through in soae batch and continuous flow studies. The acid and
base neutral extractablc compounds generally did not break through the GAC
process.
Data in Table 21 indicate that the activated sludge process completely
removed the few organic priority pollutants leaking through the GAC system
even though overall TOC removal declined. The continued remcval of organic
priority pollutants may be due to stripping, biological degradation, or
adsorption to sludge floe.
As expected, neither the GAC nor AS process effected removal of either
total cyanide or CN . Hcvever, greater than 99 oercent total phenol removal
was observed, which is consistent with results of previous studies.
An off-gas sample from the aeration chamber of the activated sludge
reactor was collected using a cold trap (acteone and dry Ice) to condense and
freeze off-gas vapors. Air flow to the reactor was approximately 2 1/m and
the collection period was four hours. The following organic priority pollu-
tants were detected in this sample:
Methylene Chlorius 1.02 ug/l air
1.2-Dichloroethane 1.04 ug/l air
Benzene 0.250 ti£/l air
Perchloroethylene (tetrachloroethylene) 0.125 ug/l air
Toluene 0.0875 ug/l air
87
-------
TABLE 21. TOC AND SPECIFIC POLLUTANT DATA FOR
GRANULAR ACTIVATED CARBON/ACTIVATED
SLUDGE PROCESS TRAIN (mg/1)
[Dates of Sampling shown on Figure 27]
Raw
Compound Ground-
water
9-16
TOC
Total Cyanide
CNA
Total Phenol
Methylene chloride
1 , l-Dichloroethene
1 , 1-Dichlo roe thane
Trans-1 ,2-dichloro-
ethane
Chloroform
1 ,2-Dichloroe thane
1 , 1 ,1-Trichloroe thane
Trichloroethylene
Benzene
1,1, 2-Tr ichloroethane
Perchloroethylene
Toluene
Chlorobenzene
Phenol
2-Chlorophenol
2,4-Dichlorophenol
1 ,2-Dichlorobenzene
Dibutyl phthalate
637
NA
NA
NA
2.1
1.6
2.4
0.06
9.8
72
7.6
0.06
1.2
0.11
0.49
2.3
0.23
0.025
0.040
0.010
0.085
ND
GAC
Effl.
9-16
380
NA
NA
NA
0.029
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Raw
Ground-
water
9-23
929
0.11
<0.05
16
14
0.06
0.17
0.04
0.70
25
0.39
0.03
1.5
0.07
1.9
0.97
0.029
0.028
0.036
0.010
0.077
ND
GAC
Effl.
9-23
604
0.21
<0.05
<0.16
0.01
0.01
0.02
ND
0.06
1.4
0.04
ND
0.02
ND
ND
0.05
ND
ND
ND
ND
ND
ND
AS
Effl.
9-24
90
0.23
<0.05
<0.10
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.05
GAC
Effl.
10-1
770
0.23
<0.05
<0.10
0.16
NT)
NT)
ND
ND
0.05
ND
ND
ND
ND
ND
0.01
ND
ND
ND
ND
ND
ND
AS
Effl.
10-1
183
0.20
<0.05
<0.10
ND
ND
ND
ND
ND
ND
KD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NA - Not Analyzed
N*D - Not Detected
No other priority pollutants detected at 0.01 mg/1 detection Unit
88
-------
XE-347 resin also was examined as a prctreatment adsorption process.
Operating conditions for resin adsorption were as follows:
o 3 columns in series
o columns were 2.54 cm dianeter and contained resin bed
depths of 48.3 cm, 55.9 en, and 52.1 cm, respectively
o total BV « 792 cm3
o downflow operation at 41 to 50 ml/Bin (3.11 to 3.79 BV/hr)
o EBCT ranged from 19 to 16 nin
When the pretreatment process was converted frcm GAC to XE-347, there was a
rapid loss in TOC removal capacity. A second resin trial produced similar
results. In both cases, TOC removal diminished to less than 59 percent after
about five bed volumes were loaded and appeared to stabilize at 10-20 percent
removal for at least 120 BV. The shape characteristics of the TOC break-
through curves are similar to those of GAC except that TOC removal declined
much more rapidly. The period of operation with XE-347 resin was from day 2
through day 27 in Figure 25. Subsequently the adsorber 'was switched to
activated crabon whereupon overall performance improved substantially. As
shown on Table 22, activated sludge units following resin pretreatment were
not able to produce effluents containing less than 100 mg/1 TOC.
Adsorption/Anaerobic Biological System—
Anaerobic biological treatment was believed to be a candidate treatment
process because of the high organic content ct the groundwater and because the
air pollution potential associated with volatile priority pollutant stripping
in the activated sludge process could be avoided.
Operating conditions for the upflow anaerobic filter (UAF) apparatus,
which is described in Section 3, were as follows:
o organic loading rate 26.4 to 52.9 Ib TOC/1000 ft3/d
o hydraulic flow rate - 1.15 to 2.0 ml/min
o EBCT - 13.1 to 22.8 hr
o temperature - 35"C
Performance of the GAC/UAF process train is illustrated in Figure 28. TOC
removals by the process train and individual processes are summarized below:
average range
TOC removal by GAC/UAF train: 66% 38-81Z
TOC removal by GAC process: 31% 10-467.'
TOC removal by UAF process: 50* 12-67%
89
-------
TABLE 22. TOC REMOVAL BY XE-347 RESIN
Wastewater
Processed
(L)
3
6
12
17.5
24.9
29.8
Column 1
BV
Loaded
12.2
24.5
50
71.4
102
122
Z TOC
Removal
20
16.3
9.6
25.2
10.4
10.4
BV
Loaded
5.68
11.4
22.7
33.1
47.2
56.4
Column 2
Z TOC
Removal
38.5
23.7
18.5
35.6
17.8
16.0
Column
BV
Loaded
3.79
7.58
15.2
22.1
31.4
37.6
3
Z TOC
Removal
57.0
23.0
20.0
39.9
19.0
19.0
Columns recharged with virgin resin
2.46
4.92
9.92
14.8
17.2
22.1
27.0
8.57
17.1
34.3
51.6
59.9
77.0
.--.3
31.9
19.9
18.7
15.8
10.9
8.2
8.2
4.49
8.98
18.0
27.0
31.4
40.3
51.1
43.9
29.8
24.6
21.1
18.6
16.9
14.8
2.95
5.89
11.8
17.7
20.6
26.5
32.3
66.7
33.9
33.9
25.7
23.0
16.9
18.0
90
-------
1000-
BOO
•Converted from
acwoge to groundwoter
Duration (days)
Figure 28. Performance of CAC/Anaerobic Filter Process Train.
-------
UAF effluent TOC increased as TOC leakage from the GAG pretreatment process
increased. Results of one six hour batch air stripping study indicated that
UAF effluent contained about 40 percent (117 mg/1) strippable TOC at the time
the sample was collected. Overall, the GAC/UAF process train, with an upper
TOC removal limit of about 81 percent did not perform as well as the GAC/AS
system.
Selected operational data (TOC loading, effluent pH, sludge pH, sludge
total alkalinity, volatile acids concentration, and gas production) are
Indicated in Figure 29. Gas production during the study averaged 505 ml/g TOC
fed. In an attempt to bring sludge pH into a range reported to be most
optimal (pH 7.2 to 7.6), tne GAC Influent pH was adjusted to pH 7.0 to 7.5.
This had no apparent effect on performance.
Figure 30 illustrates performance of a process train consisting of
GAC/upflow anaerobic filter/activated sludge. These results indicated that
performance of the AS process in the train is inversely proportional to GAC
performance; that is, as leakage from the GAC column increased, the amount of
overall removal attributable to the AS process increased. Data indicate that
this largely may be due to stripping in the aerobic system. Batch air strip-
ping tests showed minimal TOC removal from the UAF effluent when the GAC
system was performing at its highest levels, whereas, 40 percent TOC removal
by stripping was reported when GAC performance was poor. Performance of the
entire system was not as good as the GAC/AS process train; i.e., it did not
maintain low effluent TOC levels (less than 50 mg/1) for as long as the GAC/AS
train. However, both systems appear to be able to produce effluent TOC levels
below 100 mg/1 for equivalent durations.
Chemical Oxidation Pretreatment with Ozone
Preliminary batch grounduater ozonation studies were conducted under the
following conditions using a Welsbach Model T-408 laboratory scale ozone
generator:
o ozone production using air feed
o ozone gas flow rate - 2 1/mln
o ozone dose - approximately 2 g/hr (generator
operating at 90V)
o contact time - up to 9 hr
o batch volume - 15 1
After conducting studies with distilled water to assure good mixing, ozone
transler studies using groundwater were completed. Ozone measurements were
made according to Standard Methods (4) using the lodometric Method.
After several preliminary batch ozonation studies which indicated little
reduction in groundwater TOC (which would be expected in view of the parameter
92
-------
too
80
60
40
20 •
0-
5OO
290
0-
1900
1000
50O
9
8
7
6-
29
2O
19
10-
8
6
4
2
0-
(Oafes correspond with figure 28 )
% TOC Removal
Volatile Acids
(mg/l)
Alttalinlty
(mg/l)
TOC Load (g/ft?«0)
Gas Production
(ml/min)
-o-'
-o-o-
6789 II 13 19 17 19 21 23 29 27 29 31 33
Duration (days)
Figure 29. Anaerobic Filter Operation.
93
-------
e 6AC Influtnt
O 6AC Effluent
A UAF Effluwit
Q AS Effluent
13 17 21 29 29 32 33 33 43 47 91 99
•7 101 109 109 113 117 121
Duration (dayi)
Figure 30. Performance of GAO/Anaeroblc Filter/Activated Sludge Process Train.
-------
being measured and Che mechanisms of the ozone reaccion), studies were made to
determine if ozonatlon enhanced either adsorption or biologic/il treatment.
Effects on adsorption were determined by ozonating a batch of raw ground-
water and then conducting adsorption isotherm tests using activated carbon
(FS-300) aid resins (XAD-4, XE-340, and XE-347). To measure the effect of
stripping during ozonation, a parallel system was operated at the same gas
flow rate feeding air rather than ozone and adsorption isotherms were pre-
pare a. Operating conditions for these studies were as follows:
o air or ozone gas flows - 2 1/mln
o air or ozone contact times - 2.5 hr
o groundwater Latch volume - 7.5 1
o ozone dose - about 2 g/hr (at 90V)
o sorbent doses - 0.5 to 106 g/1
o sorbent contact time - 2 hr
o sample temperature - 22 Co 25°C
o sample pH - 9.6
Results are summarized in Table 23. No cl»ar difference IP adsorption process
perfortKan:e was observed with the two pretreatment techniques (aeration and
ozonation). As before, results did indicate better TOC removal by activated
carbon than by resins.
Ozonation as a pretreatment before biological processes also was exam-
ined. Batch ozonated groundwater served as feed for an activated sludge
process, and as feed for a GAC/AS process train.
Figure 31 Illustrates results for a representative portion of these
studies. They indicate that:
o preozonation did net improve AS performance which remained at about 40 to
SO percent TOC removal.
o preozonation did not improve performance nor extend TOC breakthrough
characteristics of :he GAC process.
Post-Treatment with Granular Activated Carbon
To provide a prelixinaiy assessment of CAC as a polishing rather than a
pretreatment process, an isotherm study was conducted with effluent from the
O./AS train using FS-300 povered activated carbon. Then, a continuous flow
CAC column was placed on-line co form a O./AS/GAC process train. Results of
the isotherm study, conducted with O./AS effluent (282 mg/1 TOC) after two
hours contact time are presented belowf
95
-------
TABLE 23. SUMMARY OF BATCH OZOKATIlN AMD ADSORPTIOH STODtES
SAMPLE
SORBBrt SOEBQff
DUE
(g/1)
FINAL
TOC
C (ng/1)
TOC SORBENT
SOBBED LOADING
X(Bg/l) X/H(og/g)
OVERALL
TOC
REMOVAL(%)
Raw groundwater
Blank-groundwater
after ozoaatlon
Blauk-gxaundwater
alter aeration
1050
1020
1020
Blank-ozonatlon
and shaking
Blank-aeration
and shaking
Ozonated FS 300 0.5
5
50
106
XAD 4 0.5
5
50
106
XE-340 0.5
5
50
106
XI-347 0.5
5
50
106
Aerated FS 300 0.5
5
50
106
XAD 4 0.5
5
50
106
985
940
900
815
633
573
984
942
882
852
970
950
920
888
985
930
830
730
876
754
609
560
925
912
850
767
85
170
352
412
1
43
103
133
15
35
65
97
0
55
155
255
64
186
331
380
15
28
90
173
170
34
7.0
3.9
2
8.6
2.1
1.2
30
7
1.3
0.9
0
11
3.1
2.4
128
37.2
6.6
3.6
30
5.6
1.8
1.6
14.3
22.4
39.7
45.4
6.3
10.3
16.0
18.9
7.6
9.5
12.4
15.4
6.2
11.4
21.0
30.5
16.6
28.2
42.0
46.7
11.9
13.1
19.0
27.0
a. Calculated on the basis of raw groundvater TOC and final TOC after adsorption
Sorbent contact tlee - 2 hr
Sample pH - 9.6
Sample temperature - 22 to 2S°C
96
-------
o-
10
20-
100-
O Ozone a AS traatmont
A Ozono & GAC treatment
0 Ozona.GAC a AS treotmont
Duration (days)
Figure 31. Comparison Between Process Trains Using Czone .
-------
M Cf X/M
carbon dose final TOG (mg/1) TOG adsorbed (mg/g carbon)
0 274
0.5 g/1 233 82
5. g/1 144 26
SO. g/1 20 5.1
100. g/1 6 2.7
These data are illustrated by the isotherm shown in Figure 32. Comparing some
of these data with previously presented sorption Isotherm data for raw ground-
water and ozone pretreated groundvater suggests that much lower effluent TOG
concentrations can be produced by the process train of O./AS/GAC. However,
continuous flow operation of the O./AS/GAC process train showed no advantage
to GAC polishing. Under the following operating conditions for the GAC
process, the O./AS/GAC process train was less efficient than the GAC/AS train:
hydraulic loading rate: 0.5 gpm/ft2
EBCT: 2.3 hr
72 BVs processed (-65.9 mg TOC loaded/g GAC)
98
-------
100
§ 40
JO
8 30
o>
^
•« 20-
O
o
10
9
9
7
6
3'
4
S -
Treatment Train-Ozone/AS/6 AC
Feeds affluent from Ozone/Activated
Sludge Train (TOC)0 = 282 ma/I
10
30 90
too
300
Residual TOO (C, ) mg/l
Figure 32. Adsorption Isotherm, Composite Groundwater Pretreated
by Ozone/Activated Sludge •
99
-------
SECTION 5
STUDIES USING GROUNDWATER FROM THE
GRATIOT COUNTY LANDFILL
BACKGROUND
The Gratiot County Landfill located near St. Lcuis, Michigan was used
primarily for disposal of municipal solid waste; however, between 1971 ~nd
1973 122,000 kg (269,000 pounds) of waste containing 60Z to 70% polybronin-
ated/biphenyls (PBB) also was disposed there (6). As a result of a previous
PBB incident in Michigan in 1977, the Department of Natural Resources (MDNR)
began investigating site conditions. PBB and other contaminants vere round in
the shallow groundwater aquifer; isoconcentration contour maps were prepared
for several parameters. Table 24 summarizes groundwater quality in the middle
sand aquifer.
Because one remedial measure under consideration at Cratiot County
Landfill involved encapsulation by installation of an impermeable cover and
subsurface barrier and a well point system for groundwater withdrawal, MDNR
expressed interest in the on-going Baker/TSA groundwater treatability project.
Croundwater quality at Gratint County Landfill differed considerably from that
at the Ott/Story site; thus it was believed that this waste stream would
provide a different set of conditions to evaluate selected technologies. The
technologies judged to be suitable candidates were granular activated carbon
adsorption, coagulation/precipitation, sedimentation, filtration, ion ex-
change, and reverse osmosis.
PROCEDURES
Of the mraerous existing monitoring wells, well DW-7 was selected for use
in this study because previously it had yielded cmong the more highly contam-
inated samples and also because the volume yield Jas sufficient to collect the
quantities of groundwater necessary for experimental studies. Samples from
well DW-7 were collected by MDNR personnel. The procedure involved evacuating
five well volumes using a manual bailer, allowing the well to recharge, and
then sampling. Samples were placed in 18.9 1 (five gallon) polyethylene
carboys, and shipped to 3aker/TSA's laboratory in Beaver, Pennsylvania. The
time span between sample collection and receipt at the laboratory was about 24
hours. No preservatives were added at the tine of collection or receipt.
Instead, one carboy fron the sampling batch was selected for immrdiane use and
others were frozen until needed. As required, carboys were allowed to thaw at
room temperature prior to use. Freezing was judged to be the most suitable
preservation method to minimize transformations which would affect technology
evaluations without detrimentally affecting vasce stream properties. Prior to
100
-------
TABLE 24. GRATIOT COUNTY LANDFILL QUALITY OF MIDDLE SAND AQUIFER
(1)
PARAMETER
CONCENTRATION RANGE fag/1)
PBB
Chemical Oxygen Demand
Total Dissolved Solids
Toral Organic Carbon
PH
Ammonia Nitrogen
Total rjeldahl Nitrogen
Chloride
Sulfide
Hardness
Chromium
Iron •
Nickle
Lead
Zinc
Cadmium
Phenol
Bromine
Arsenic
0.012 - 0.12 vg/1
1.0 - 140
290 - 710
0.90 - 24.0
7.1 - 11.6
0.02 - 0.59
0.02 - 13.0
1.0 - 39.0
0.01 - 1.2
36.0 - 760.0
C.OOi - 0.40
0.91 - 80.0
0.010 - 0.11
0.001 - 0.58
0.2 - 87.0
0.002 - 0.049
0.003 - 0.28
0.002 - 1.9
0.003 - 0.038
(1)
Source: Michigan Department af Natural Resources. Hydrogeologi-
cal Investigation and Engineering Alternatives for Control Measures
Gratiot County Landfill Michigan. Resource Recovery Division,
Department of Natural Resources, Lansing, Michigan. June. 1979.
101
-------
freezing, a representative sample was withdrawn and analyzed for PBB, and
total and dissolved metals including most priority pollutant metals. Results
were conpared with drinking water standards and other water quality criteria
to identify areas of concern and principal parameters to measure treatment
process effectiveness. Initial technology evaluations then were designed.
Granular media filtration was evaluated on a batch basis using a 50 ml
buret containing 23 ml of white sand which passed a No. 40 sieve ('0.0165 inch
particle size). Flow rate was 9.5 ml/min. (approximate surface loading rate
of 1.8 gpm/ft.2). Sample collection spanned the period between the passage of
74 through 99 bed volumes.
Gravity sedimentation was examined on a batch basis by monitoring quies-
cent settling In a one liter beaker. Turbidity initially was used to measure
performance. Results indicated that turbidity decreased from 150 NTU to 100
NTU in 15 minutes and stabilized at about 85 NTU after 1 to 3 nours. Subse-
quently supernatant samples were drawn after 1 hour for analysis of the metals
of concern.
Following batch evaluation of granular media filtration and gravity
sedimentationi the following continuous flow studies where initiated:
o sand filtration i -Ing a 2.54 cm ID by 32.5 cm Plexiglas column
o granular activated carbon (GAG) using a 1.9 cm ID by 133 cm Plexi-
glas column
o sand filtration followed by GAG using columns similar to those
described above
Once these studies had begun, raw groundvater being used was found to
have low metal concentrations and no PBB at a detection level of 0.001 mg/1
(although 0.68 mg/kg of PBB was measured in sediment filtered from the ground-
water samples). Therefore, la view of the raw groundwater quality, continuous
flow evaluations were discontinued.
RESULTS
Analysis of samples initially received at the Baker/TSA laboratory
indicated that metals were predominantly in tha insoluble form. Thus, batch
evaluation of granular media filtration and gravity sedimentation were exam-
ined first. Results along with raw groundwater quality data are summarized in
Table 25. Only the metals found to exceed interim primary drinking water
standards or water quality criteria were used to monitor process performance.
Granular media filtration and gravity sedimentation (without pH adjustment or
chemical additives) provided significant removal of the insoluble fraction of
the metals.
It was concluded that these physical separation processes effectively
remove metals associated wr.th silt in the sample. Because PBB also appears to
be associated with the slLt, it is expected that these processes also would
achieve significant levels of PBB removal.
102
-------
TABLE 25. CRATIOT COUNTY LANDFILL GROUMDWATER METALS CONTENT - RAW AND TREATED
Paiameter
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Zinc
Iron
Raw Typical Sand Gravity Sedimentation
Croundwater Well Filtration Supernatant .
Total0 Soluble" DH-7C Effluent Total8 Soluble"
(mg/1) (ine/1) (mg/1) (mg/1) (mg/1) (mg/1)
<0.02
<0.002
0.02
0.05
0.20
0.11
0.0001
0.10
0.055
<0.01
12.8
31.6
<0.02
<0.002
0.01 <0.003 0.01 0.02 <0.01
<0.02 0.024 0.07 <0.02
0.02
<0.03 0.58 <0.03 <0.03
<0.0005
0.06 0.011 0.04 0.04
0.008
<0.01
1.56 3.1 2.88 3.00
<0.03 7.1 0.20 2.28
a. Sample was digested for total metals
b. Sample was filtered and acidified before analysis
c. Hydrogeologlcal Investigation and Enginceilng Alternatives for Control Measures
Crntlot County Landfill, Michigan Resource Recovery Division. DNR, Lansing, MI.
Final Report June, 1979 Exhibit 14. Parts J-0
-------
SECTION 6
STUDIES USING LEACHATE FPOM THE MARSHALL LANDFILL
BACKGROUND
Marshall Landfill located in Bouldar County, Colorado is a privately
operated, predominantly municipal solid waste landfill that accepted some
industrial wastes froa surrounding light manufacturing and fabricating Indus-
tries. In 1979, seepage was observed to be draining from the fill into a
small surface waterway used to convey water from Marshall Lake to the
Louisville Reservoir which is part of the drinking water supply for
Louisville, a nearby Boulder County municipality. Analysis of the seepage
indicated the presence of numerous priority and non-priority organic compounds
ct concentrations varying from less than detection levels to about 6 mg/1.
Table 26 summarizes available seepage and groundwater composition data at
several sampling locations .it the landfill.
PROCEDURES
Seepage collected in an impoundment designated as Lagoon 2 was selected
for use in laboratory technology evaluations. Although limited composition
data were available for this location, the TOC was significant (168 mg/1).
Moreover, an adequate volume of sample for use in treatability studies could
be collected easily and dependably which was not the case for other locations.
Samples were collected by Boulder County Health Department personnel in
five-gr.llon polyethylene carboys, express air shipped to the 3aker/TSA lab-
oratory and initially either used Immediately or frozen. However, it was
found that freezing altered sample composition. Samples frozen and then
thawed at room temperature had TOC concentrations up to 58 percent lower than
the concentration prior to freezing. As a result, it was necessary to store
subsequently obtained samples in tightly closed, five-gallons shipping con-
tainers at room cemperature until needed for use in the study.
The evaluation protocol using Marshall Landfill seepage is outlined
below:
(1) Batch adsorption isotherm tests with 0.5 to 2.5 g/1 doses of the
following sorbents:
104
-------
TABLE 2o. ANALYSES OF WATERS AT MARSHALL LANDFILL
Concentration (mg/1)
Contaminant Well 1 Leachate Seep Lagoon 2
methylene chloride 2.00. 2.183 0.061, 0.200
1,1-dichloroethane 0.100. 0.413 0.045. 0.100. 0.194 *
1,2-dlchloroethylene 0.053 0.050, 0.130
benzene 0.100 0.011
toluene 0.724. 1.200 <0.010, 0.020
ethylbenzene 0.0100, 0.110 *
1.1.1-crichloroeehane 0.021 0.100, 0.227
chlorobenzene *
vinyl chloride 0.182 <0.010, 0.014
trichlorofluoromethane 0.112 <0.010, 0.078
1,1,2,2-tetrachloroethane *
2-othoxypropane *
trichloroethylene 0.300. 0.616 0.010, 0.040, 0.053
chloroform * *
chloroethane * <0.010, 0.018 *
1,2-transdlchloroethylene l.COO, 5.65 <0.010, 0.202. 0.062
1,2-dichloropropane 0.014
oechyl chloride 0.010
dichlorodifluoramechane 0.292 O.C65
tetrachloroethyl.ene 0.300. 0.616 0.035. 0.1000. 0.162
1,3-dichloropropylene *
bis(2-ethylhexyl) phthalate <0.010, 0.012 *
icenaphthane *
butylbenzyl phthalate *
dl-n-butyl phthalate 0.033 * *
diethyl phthalate 0.217 * 0.0'2
phenol 0.088 0.272 *
2,4-dimethylphenol *
acrolein *
TOC 168
^Detected at less than 10 ug/1
105
-------
activated carbon: Calgon FS-300
Westvaco Nuchar SA
Darco HOC
resins: Rohm and Haas XAD—4 (polymeric)
Rohm and Haas XE-340 (carbonaceous)
Rohm and Haas XE-347 (carbonaceous)
(2) Aerobic biological treatment using the activated sludge
process - A culture of activated sludge organisms was obtained from
a large publicly owned treatment works having a substantial indus-
trial contribution. This sludge was used to seed a Swisher reactor
which then was fed Lagoon 2 wastewater at a rate that maintained a
hydraulic retention time of 6 hours. Attempts to acclimate an
activated sludge culture to raw seepage continued over a four-week
period.
(3) Continuous flow adsorption tests - Continuous flow granular acti-
vated carbon (GAC) systems consisting of two or three columns in
series were operated. Columns were 1.90 cm ID (0.75 in). The
two-column system was loaded with approximately 167 g of FS-300 GAC;
'the three-coluim system contained about 268 g of FS-300 GAC.
Additional system operation details are provided below.
(4) Activated sludge treatment of CAC pretreated seepage - A process
train consisting of one 1.9 cm (0.75 in) ID GAC column containing
about 87 g of FS-300 GAC followed by a one liter activated sludge
reactor was used to determine if GAC pretreatment enhanced activated
sludge performance in a manner sini'ar to the results found at the
Ott/Story site.
(5) Air stripping - Bate!; air stripping was evaluated by aerating
wastewater for up to 24 hours.
RESULTS
Batch Adsorption Isotherms
Results of adsorption isotherm studies are presented in Figure 33 and
Table 27. The activated carbons effected better TOC removal than did the
resins. This is similar to the results obtained at the Ott/Story site. The
three carbons performed similarly. Of the resins considered, the XE-347 resin
produced noticeably better results than the others.
106
-------
200
100
I
e SO
0
s
o
o
10
S
carbons:
A Calgon FS-300
• Ntichar SA
• Oaree HOC
raalna:
A XE-340
D XAD-4
O XE-347
realns
10
residual TOO (Cf)
Figure 33. Adsorption Isotherms.
107
100
-------
TABLE 27. ISOTHERMS AT PREVAILING pH (7.95) - MARSHALL LANDFILL
Conditions: T = 22°C
initial TOC • 168 mg/1
Sorbent
Carbons
Calgon FS-300
Nuchar SA
Darco HDC
Resins
XE-347
XE-340
XAD-4
Blank
Dose (mg/1)
0.5
5.0
25.0
0.5
5.0
25.0
0.5
5.0
25.0
0.5
5.0
0.5
£.0
25.0
0.5
5.0
25.0
_
Equilibrium TOC
(ng/1)
113
26
10
108
43
23
126
49
18
155
43
152
148
145
150
140
119
164
mg TOC sorbed/g
of sorbent
102
28
6.2
112
24
5.6
76
23
5.8
18
4.2
24
3.2
0.'6
28
4.8
1.8
-
108
-------
Activated Sludge Treatment
Although nutrient levels. pH, dissolved oxygen concentration, and heavy
metal concentrations were determined to be within acceptable ranges for
aerobic biological treatment. attempts at activated sludge acclimation to raw
groundwater were unsuccessful ao measured by TOC removal and biological solids
growth. Influent and effluent TOC averaged about 93 mg/1 and attempts at
maintaining sludge solids by frequent reseeding were unsuccessful.
Continuous Flow Carbon Adsorption
Based upon adsorption isotherms, continuous flow systems using FS-300
granular activated carbon (GAC) were further evaluated. Operating conditions
for systems with two and three columns in series are outlined below:
Column Diameter, cm (in)
GAC Contents, g
2-Column System 3-Column System
1.90 (0.75 )
Contact Time. oin.
Hydraulic loading rate
l/m2/sec (gpm/fta)
Bed Vol'ine, ml
Column 1-87
Column 2-80
Column 1-6.7
Column 2-6.2
1.54 (2.24)
Column 1 - 90.5
Column 2-93
Column 3-85
Column 1 - 18.1
Column 2 - 36.7
Column 3 - 53.7
0.59 (0.86)
Column 1 - 174
Column 2 - 160
Column 1-181
Column 2 - 186
Column 3 - 170
Influent TOC during these studies ranged from 126 to 182 ffig/1.
For the 2-coluran system, results ire presented in Table 28 and Figures 34
and 35. At a system empty bed contact time (EBCT) of about 13 minutes, 91
percent TOC removal was achieved inir.'ally; however, after processing about 50
bed voluaes (BV), removal had decreased to 70 percent. Effluent TOC was about
40 mg/1.
Results for the 3-column system are presented on Figures 36 and 37; a
comparison with the 2-column system is shown in Figure 35. Those data Indi-
cate slightly better performance at the increased contact time. During
109
-------
TABLE 28. CRANULATKD ACTIVATED CARBON PERFORMANCE - TWO COLUMN SYSTEM
(MARSHALL LANDFILL SEEPAGE)
Column 1
Ciioula- Cumula-
tive tlvi
Operating Flow
(Hln)
IS
30
60
110
1BO
240
300
360
420
460
540
600
660
720
.39
.78
1.56
3.12
4.68
6.24
7.8
9.36
10.92
12.48
14.04
15.6
17.16
18.72
Influ-
ent
TOC
137
117
137
1S7
137
137
137
137
137
126
126
126
126
126
Cumula-
tive TOC
Loading
53
106
212
425
638
851
1064
1277
1490
1647
1884
2081
2278
2475
Efflu-
ent TOC
(mg/1)
21
23
25
36
"3
47
53
52
55
59
65
69
69
69
TOC
Removal
t
85
83
82
74
69
66
61
62
60
53
48
49
45
4J
TOC adsorbed Bed
(eg TOC/g Voluaes
carbon) Processed
.6 2.2
1.
2.
^a
7.
9.
12.
14.
17.
19.
21.
23.
26.
28.
4.5
8.3
17.8
26.7
35.7
44.6
53.5
62.4
71.4
80.3
89.2
98.1
107.0
Efflu-
ent TOC
(•g/1)
12
18
19
24
26
29
28
31
32
30
32
35
38
Total System
Colunr. 1 and 2
TOC
Renoval
%
91
87
86
82
81
79
80
77
77
76
75
74
70
TOC adsorbed
lug TOC/g
carbon)
.3
.6
1.3
2.5
3.8
5.1
6.4
7.6
8.9
10.1
11.3
12.5
13.6
Bed
VolUBM
Processed
1.2
2.3
4.7
9.3
14.0
18.7
23.4
28.0
32.7
37.4
42.0
46.7
51.4
-------
I.O-i
0.8-
o
o
o
d>
c
£
"5
o.e-
£ a:
o
0.4-
0.2-
0.1
Column 1 effluent
Column 2 effluent
16
30
45
60
76
80
106
120
Bed Volumes Processed
Figure 34. Breakthrough Curve - 2 Column CAC System.
-------
100
o
2
80
40H
20-
2 column system:
+ Column 1
O Total system
3 column system:
• Column 1
A Columns 142
• Total System
20
40
60
80
100
120
140
Mg TOC loaded / g carbon
Figure 35. GAG Performance-2 and 3 Column Systems.
112
-------
120i
a
o
n
o
B
1
O
O
UJ
100
eo-
60-
40-
20-
9 Plrot column «fflu«nt
A Second column effluent
• Third column effluent
(§) Last sample before backwaeh
Q Sampling of ayatem effluent for
priority pollutants (See Table 29
20
~T— —T— —r— —i—
40 90 60 100
mg TOG loaded / g carbon
120
-------
120
100
80
9
o
E
^0
o eo
40-
20-
0 60 100 160 200 260
Fiyure 37. VOC Removal vs. Seepage Volume Processed - 3 Column GAC System.
r100
-80
•eo
o
^\
*
-40
20
—r—
300
-------
operation of the 3-colunm system, the lead column frequently plugged with silt
present in the seepage. When this column was backwashed, temporary improve-
ment in TOC removal was observed (see Figure 36).
To evaluate removal of organic priority pollutants, samples of raw
seepage and effluent from the 3-colunm system were obtained at three points on
the operating curve as shown en Figure 36. These points correspond to TOC
breakthroughs of about 52, 101, and 227.. Priority pollutant and TOC results
are summarized in Table 29. Priority pollutants detected in the raw seepage
but not detected in the carbon column effluents were: benzene, 1,2-dichloro-
prcpane, ethylbenzene, tetracholorethylene, toluene, diethyl phthalate.
Compounds detected in at least one effluent sample but in not the raw seepage
were: 3,3-dichlorobenzidene, anthracene, bis(2-c'uloroisopropyl)ether, di-n-
octyl phthalate, phenanthrene, isophorone. Other pollutants were partially
sorbed but were detected in at least one effluent sample. No trend of in-
creasing priority pollutant breakthrough with increased TOC breakthrough is
apparent.
To illustrate abserved variations in GAC system performance, results of
evaluations using Marshall Landfill seepage and groundwatcr from the Ott/Srory
site are compared on Figure 38. At comparable TOC loading rates and operating
conditions, TOC adsorption per unit weight of GAC was approximately two times
greater for the Marshall Landfill seepage than for the Ott/Story site.
Granular Activated Carbon and Activated Slr.dge Process Train
During the two-month duration of study, a process train consisting of GAC
adsorption followed by activated sludge treatment reduced TOC levels to 20
mg/1. However, the GAG column alone reduced the TOC to 23 mg/1, showing that
the activated sludge process did not contribute appreciably to TOC removal.
Air Stripping
As indicated by the data summarized below, air stripping (via batch
aeration) achieved minimal TOC removal.
Aeration Time TOC TOC Removal
(Hr.) (ng/l) (Z)
0 137
6 120 12
24 126 8
This result was not unexpected since, as can be seen from inspection of
Table 29, Marshall Landfill leachate did net contain high concentrations of
volatile priority pollutants but rather contained primarily phenolicn, aro-
ma tics, and heavier priority pollutants with low vapor pressures.
115
-------
TABLE 29. TOC AND PRIORITY POLLUTANT ANALYSES FOR THREE-COLUMN GAC SYSTEM
(MARSHALL LANDFILL SEEPAGE;
(a)
Parameter
TOC (mg/1)
benzene
chloroform
1 ,2-cichloropropane
echylbenzane
methylene chloride
tetrachloroethylene
toluene
4-nitrophenol
p-chloro-m-cresol
bis (2-ethylhexyl) phthalate
diethyl phthalate
di-n-butyl phthalate
3,3'-dichlorobenzidene
anthracene
bis (2-chlorobenzidene) ether
di-n-octyl phthalate
phenanthrene
isophorone
Raw
Seepage
175
1
5
1
2
8
1
2
17
3
16
2
2
GAC System Effluent
-------
100
80
o
o
o
40
20-
Marahall
Landfill Seepage
Ott Story Qroundwator
0 60 100 160 200
mg TOG loaded / o carbon
Figure 38. CAC Performance Comparison.
260
300
-------
SECTION 7
STUDIES USING GROUNDWATER FROM THE CLEAN UELLFIELD
BACKGROUND
In lace 1981, three wells providing 70 percent of the drinking water
supply for the City of Olean, New York were found to contain 120 to 250 ug/1
of trichloroethylene (TCE). Subsequent testing at other private wells in the
area detected TCE at concentrations of 2,000 to 9,000 ug/1. As a result, the
city had to revert to using its 60-year old filtration plant to treat an
alternate surface water supply source. To aid those relying on private wells,
small scale activated carbon adsorption systems were installed at some private
hoves with individual wells; their performance was monitored by the city and
county. Local officials requested and received Superfund status for the site
to aid problem Investigation efforts and the installation, monitoring, and
maintenance of the individual carbon treatment systems. Because of the
nationwide prevalence of TCE contamination of drinking water supplies, ground-
water from the Olean Wellfield was selected as the fourth contaminant stream
to be used to evaluate treatment technologies.
PROCEDURES
Samples from Olean well 37M were collected by municipal personnel. These
samples were placed in six completely full one-half gallon glass containers,
and shipped overnight to the Eaker/TSA laboratory in Beaver, Pennsylvania.
Analyses indicated that the groundwater had a COD of 4.8 mg/1 and a TCE
concentration of 46 ug/1, well below the anticipated concentration of 200-250
Ug/1. It was speculated that, because this well had not been used for some
time, the configuration of the TCE contamination plume may have changed from
that found during earlier problem assessments. Using these samples, batch air
stripping tests and adsorption isotherm studies were conducted at the Baker/
TSA laboratory. A second set of samples was later obtained from the combined
flow of city wells 37M and 38 M by City of Olean personnel under the super-
vision of the Cattaragus County Health Department. These samples were placed
in VOA vials, two of which were air-shipped to the Baker/TSA laboratory and
were subsequently found to contain 90 and 95 ug/1 of TCE.
Based upon this analysis and results of the air stripping and adsorption
isotherm studies, it was determined that approximately 250 gallons of ground-
water would be required to develop a granular activated carbon (GAC) break-
through curve for TCE using a bench scale system. Arrangements then were made
to obtain the required quantity of groundwater. The sample was collected from
a sample line (with a flow of 1-5 gpm) tapped into a main line served by wells
118
-------
37H and 38M (main line flow was 1,400 gpm). The sample line was used to fill
five 55 gallon steel drums; once filled to overflowing they were tightly
sealed and shipped overnight to the Baker/TSA laboratory. Sample collection
encompassed approximately 3.5 hr.; cumulative flow through the main line was
302,000 gallons. Analysis of the contents of the fifth drum collected indi-
cated a TCE concentration of 117 ug/1. The sealed, steel drums were stored at
ambient temperature at the laboratory until used.
Isotherm studies were repeated with this batch of sample. Continuous
flow CAC colunn studies then were conducted. Study conditions are described
below.
During the course of this study, the U.S. EPA Office of Drinking Water
conducted a pilot test of air stripping at Olean. Data from the pilot tests
were used to calibrate a>i EPA developed mathematical model for estimating
design parameters and treatment costs for volatile organic compound removal by
packed column air stripping. A brief description of the EFA model as well as
field test results are contained in Appendix A.
RESULTS
Adsorption Isotherm Studies
Adsorption isotherms were prepared for Westvaco Nuchar and Calgon Filtra-
sorb 300 carbons, and Rohm and Haas carbonaceous resin XE-340. Samples were
contacted with the sorbent for two hours at 20°C using a platform shaker
operated at 180 excursions/minute. Sorbent doses were 0, 4, 20, 40, 120 and
200 mg/1. At the end of the contact period, samples were filtered and placed
in VOA vials.
Figure 39, which compares Olean isotherm data with a single constituent
TCE sorption Isotherm reported by EPA (7), shows good agreement between the
results (EPA also used Filtrasorb 300). The Nuchar carbon, a powered carbon,
exhibited somewhat poorer TOE absorption characteristics. Resin sorption delta
do not show a clear trend and are not plotted. Since there were indications
that the manufacturer planned to discontinue this product, additional work
with resins was not undertaken.
Continuous Flow Carbon Adsorption
Continuous flow granular activated carbon (GAC) column studies were
conducted using two columns In series; however, to facilitate observation of
TCE breakthrough the first column was divided into three segments. Operating
data for the columns are given below:
119
-------
1001
I
10
i-
I
.0.1
0.0001
0.001 0.01 0.1
Residual Cone. (Cf) mg / JL
1.0
Data from Dot*, rJ-A. and J.M. Coh«n,
Cartoon Adsorption ifothorma for Toxic Oraanlcs, EPA-600/8-80-023.
US. EnvironnMntai Protection Agency. Cincinnati. Ohio 1980. p 332.
Otoan cfoondwater - C*.lgon Filtraaorb 300 Carbon
Ol«an groundwater - Calgon Filtratorb 300
Otoan groundwatvr. - WaaWaco Nuc.iar Carbon
Figure 39. TCE Adsorption Isotherms.
120
-------
Cumulative Average
Carbon _ Cumulative Total Bed Volumes Effluent
Column Volume (en ) CBCT (min.) Processed TCE
1A 123.8 3.1 6907 HD
IB 255.8 6.4 3343 ND
1C 387.7 9.7 2206 ND
2 793.1 19.8 1078 ND
(ND - not detected)
This systca was operated until the supply of contaminated well water was
exhausted. No TCE breakthrough was detected at that tine. However, summar-
ized below is the theoretical TCE breakthrough calculated on the basis of
published Freundlich isotherm parameter? for a constant TCE concentration of
100 ug/1:
Bed Volumes Effluent TCE
Processed Concentration (ug/1)
2000 1
5000 5
7750 10
This suggests that some breakthrough should have been detected during the
experimental study. It was observed that volatilization losses of TCE from
the storage ccntainers prior to ana during use reduced the actual influent TCE
concentration below 100 ug/1. Monitoring of these containers indicated that
TCE losses ranged up to 513! with -he average loss being 36% (27 ug/1). These
monitoring results were used to calculate the actual TCE load applied to the
carbon. The loading on Column 1A at termination of the run was calculated to
be 0.762 mg TCE/g carbon. This should have resulted in a theoretical effluent
TCE concentration of 3 ug/1. The measured value was re made of carbon effluent to investigate
the possibility of biological growth in the GAG columns and subsequent contam-
ination of the treated water. The following samples were assayed:
GAG column influent during the
processing of BV 2556-3803 =500 colonies/1 ml
Column 1A effluent after 2556 BV 87,000 colonies/1 ml
Column 1A effluent after 3,456 BV 510,000 colonies/1 ml
121
-------
These data Indicate elevated plate council following GAC treatment. This may
partially explain the non-detectable TCE levels in the carbon effluent.
Further study in this area for health effect determination may be warranted
when carbon adsorption systems are planned for the treatment of residential or
small scale water supplies.
EPA Modeling of Packed Air Stripping
The Olean site was an ideal situation for evaluation of advanced TCE
removal techniques. During the course o; Baker/TSA studies at this site, the
State of New York Department of Health requested further EPA research involve-
ment resulting in a field evaluation of TCE removal by packed column air
stripping. Operation of the field pilot system and development of a mathe-
matical model for the system was carried out by the EPA Office of Drinking
Water - Technical Support Division.
Appendix A contains a reproduced report describing the EPA field work and
evaluation. Their results show that greater than 99 percent TCE can be
removed by air stripping economically.
122
-------
REFERENCES
1. Shuckrow, A.J., A.P. Pajak, and C.J. Touhill. Concentration
Technologies for Hazardous Aqueous Waste Treatment. EPA
600/2-81-019. U.S. Environmental Protection Agency. Cincinnati,
Ohio. 1981. 37J pp.
2. Kopp, J.F. and G.D. McKee. Manual - Methods for Analysis of Water
and Wartes. 1978. EPA 600/4-79-020. U.S. Environmental Protection
Agency, Cincinnati, Ohio. 1979. 441 pp.
3. Sampling and Analysis Procedures for Screening of Industrial
Effluents for Priority Pollutants. U.S. Environmental Protection
Agency, Cincinnati, Ohio, 1977.
4. American Public Health Association. Standard Methods for the
Examination of Water and Wastewater, Fifteenth Edition. American
Public Health Association, Washington, D.C., 1980. 1134 pp.
5. Symons, James M., A.A. Stevens, R.M. Clark, E.E. Geldreich, O.T.
Lcve, Jr., and J. DeMarco. Treatment Techniques for Controlling
Trihaloaethanes in Drinking Water. EPA-600/2-81-156, U.S.
Environmental Protection Agency, Cincinnati, Ohio, 1981, 289 pp.
6. Shah, B.P. Hydrogeological Investigation and Engineering
Alternatives for Control Measures, Gratlot County Landfill
Michigan. Resource Recovery Division, Department of Natural
Resources, Lansing, Michigan. 1979. 68 pp.
7. Dobbs, R.A. and J.M/ Cohen. Carbon Adsorption Isotherms for Toxic
Organics. EPA-600/8-80-023. U.S. Environmental Protection Agency,
Cincinnati, Ohio. 198G. 332 pp.
8. EPA Office of Drinking Water, Technical Support Division, "Field
Evaluation of Trichloroethylene Removal by Packed Column Air
Stripping," May 25, 1982.
123
-------
APPENDIX A
PACKED COLUMN AIR STRIPPING PILOT TEST
CLEAN, NY - MAY 25, 1982
The United States Environmental Protection Agency (EPA), Office of
Drinking Water (ODW), Technical Support Division (TSD) is conducting a program
for evaluation of packed column air stripping for removal of volatile com-
pounds from contaminated water supplies. TSD has constructed a portable pilot
packed column air stripping system which is used to generate data for field
evaluation of the treatment process. This report discusses one in a series of
pilot packed column air stripping field tests. This field test was conducted
May 25, 1982, at Olean, NY. The contaminant monitored was trichloroethylene
in levels ranging from 170 to 210 wg/1. The packing material evaluated was 5
cm (2 in.) plastic saddles.
In November 1981 a portion of the City of Olean1s water supply was found
to be contaminated with trict.loroethylene. Subsequent analyses revealed that
three cf Clean's four municipal wells were contaminated vith trichloroethylene
In excess of 100 ug/1. These three wells, which supplied 702 of the City's
water supply, were shut down and a 60-year old filtration pl.int was returned
to service. The City Is investigating the source of the contamination and
possible treatment alternatives. The TSD pilot system was used to evaluate
the treataent alternative of packed column air stripping.
The TSD pilot packed column air stripping system (shown in Figura A-l)
consists of a 0.6 m (2 ft.) diameter aluminum column packed with 5.5 m (18
ft.) of 5 cm (2 in.) plastic saddles. Eighteen sample ports were installed at
0.3 m (1 ft.) intervals along the column height to sample the center 0.3 m (1
ft.) of the column. This sampling system allowed monitoring the concentration
profile of trichloroethylene along the column height. The column was designed
to operate at air to water volume ratios of 10, 15, 25, 50, 75, and 150.
The field evaluation at Olean consisted of operation at the 6 air to
water ratios shown in Table A-l. At Olean, 20 samples (including influent and
effluent) were collected at each air to water ratio for a total of 110 samp-
les. Fifty-six of these samples were analyzed by the liquid-liquid extraction
GC technique for trichloroethylene. These data were plotted, as shovr. in
Figure A-2, as concentration vs length of travel through the packed column.
From Figure A-2 it was observed that an effluent concentration of less than 1
iig/1 could be obtained despite the high influent concentration of 200 ug/1.
From Figure A-2 it was observed that the concentration declined, as expected,
as the water passed through the packed column. It was also apparent that
increasing the air to water ratio improved the removal efficiency.
124
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Not so apparent in Figure A-2 was the phenomena that at high air to water
ratios the concentration profile was linear; whereas, at low air to water
ratios the concentration profile was curvilinear. A transition from linear to
curvilinear was observed from the high to the low air to water ratio. This
curvature was due to the air becoming saturated with trichloroethylene in the
lower sections of the stripping column. When this happened, the packed column
was unable to effectively remove trichloroethylene from the water phase. This
condition was forced in the pilot system so that Henry's coefficient for
trichloroethylene could be determined in the field conditions experienced at
Olean.
A data analysis procedure has been developed to determine Henry's coef-
ficient, the mass transfer coefficient, and the influent concentration from
the concentration profiles shown in Figure A-2. The procedure consists of
estimating the above three parameters by fitting a concentration profile math
model to the data points using a non-linear multi-regression analysis. Equal
statistical weight is allowed for each data point. The math model is shown
below and plotted along with the data points in Figure A-2. The relative
standard deviation between the model and all the data points was 62.
Concentration Profile Math Model;
X - X * (R*A) - 1
Z T (R*B) - I
Where: A - exp Z* \a * (R - 1)
L R
B - exp Z * La * (R - 1)
L R
R =. c" * II = (G*pa/MWa) * H
I" P.. (L*pw/MWw) P
Where:
G
L
pa
pw
MWa
MWw
ZT
Z
Air loading (m m sec )
3 -2 -I
Liquid loading (m m sec )
Density of air (Kg m~ )
Density of water (Kg m~ )
.-1,
Molecular weight of air (28.8 Kg KM )
Molecular weight of warer (18.0 Kg KM'1)
Packing height (m)
Location within column measured from
bottom of column (m)
125
-------
KLa * Mass transfer coefficienc (see" )
Jt_ • Influenc concentration (ug 1 )
X, - Concentration at location Z (ug 1~ )
2
R - Stripping Factor
G" - Air molar loading (KM m~2 sec'1)
L" * Liquid molar loading (KM m~ scc~ )
H - Henry's coefficient (atm KM H-0 KM* air)
F • Operating pressure (1 atm)
The Henry's coefficient was estimated as that value which results in the
minimum relative standard deviation between the concentration profile math
model and the data points, determined by an iteration procedure. The relative
standard deviation (RSO) was computed as follows.
RSD
- A
Where: RSD - Relative standard deviation
Xi = Concentration profile data point
X - Concentration profile math model
2
N " Number of data points
This relationship is shown in Figure A-3 for the 10:1 air to water ratio.
Throughout Figure A-3 the influent concentration and mass transfer coeffi-
cients were determined by a regression analysis. This relationship revealed
that a minimum relative standard deviation occurred at 3.42. This minimum
relative standard deviation indicated that the estimated value for Henry's
coefficient was 175 atm KM H.O KM'1 air (0.13 atm m3 H.Onf3 air).
The mass transfer coefficients for each air co water ratio were deter-
mined by a method similar to that used in determining Henry's coefficient.
The relationship between the relative standard deviation and each mass trans-
fer coefficient are shown in Figure A-4. In Figure A-4 the Influent concen-
tration was optimized throughout while the Henry's coefficient was held
constant at 175 atm. Similar to Figure A-3, the minimum points indicated the
best fit values for the mass transfer coefficients. The best fit values for
the mass transfer coefficients are included in Table A-l.
126
-------
From Figure A-4 it was observed that a trend existed between the best fit
value for the mass transfer coefficient and the air to water ratios. For
volatile compounds! such as trichloroethylene, this trend is generally be-
lieved to be due to the liquid loading. On-, of the key parameters in design-
ing a packed column air stripping system is this relationship between the mass
transfer coefficient and the liquid loading. Examination of this data set
revealed that the relationship was log-log linear between liquid loadings
0.005 through 0.026 n3 m~2 sec'1 (7.3 through 38 gal. min"1 ft~2). Above
0.026 m3 m~" sec**1 liquid loading the relationship was not linear. This was
probably due to hydrauiically overloading the packed column. This relation-
ship is shown in Figure A-5. A linear regression of the data between liquid
loadings 0.005 and 0.026 m3 n~2 sec'1 resulted in a correlation coefficient
of 0.996 — an excellent fit. The equation of the best fit line was as
follows.
K. - 0.12*L°'59 (for 5 cm plastic saddles)
LA
Where: 1C - Mass transfer coefficient (sec'1)
L - Liquid loading (m3 m'2 sec'1)
fnr n nn^
-------
Table A-2 presents a series of packed column air stripping systems and
cost estimates for trirhloroethylene removal efficiencies from 80 to 99Z. The
packed column systems shown in Table A-2 are based on the K equation and
Henry's coefficient. The cost estimate indicated that 99% tr&hloroethylene
removal can be obtained with a total production cost of l.9c m3 (7.2c per
1,000 gal) using 5 cm (2 in.) plastic saddles.
The packing material investigated in this study was 5 cm (2 in.) plastic
saddles. TSD has also investigated at other municipalities trlchloroethylene
removal using 1.5 cm (1 in.) plastic saddles. The Henry's coefficient of 175
atm observed ac Olcan, NY, was in excellent agreement with Henry's
-------
Figure A-l. Packed column air stripping pilot
system at Olean, NY on 5/25/82.
129
-------
o
o
o
o
•*
a
e o
O T*
o
c
O
o
O)
CM
I
o
Concentration
Profile Math Model
Alr:V/ater
Ratio
10
4-
tu
43
22
12
5.7
2.1
0.8
0
12345
Length of Travel Through Column (m)
Figure A-2. Trichloroethylene concentration
profile at Clean, NY on 5/25/82.
-------
AlnWater Ratio
bptlmum Value for
Henry's Coefficient
10 100 1000
Henry's Coefficient (atm)
10000
Figure A-3. Relative standard deviation vs.
Henry's coefficient for trichloroethylene
at Glean, NY.on 5/25/82.
-------
Alr:Water Ratio
Note: Henry's Coeff.
Held Constant
at 175 atm
Optimum
Mass Transfer Coefficients
0.01
0.02
0.03
O.04
-1
0.05
Mass Transfer Coefficient (sec )
Figure A-4. Relative standard deviation vs. KLa
for trichloroethylene at Clean, NY
on 5/25/82.
-------
CO
*•» o
'o
«
09
o
u
!°.
o o
CO
I-
a
a O
2C O
H 1—I—I Mill
0.001
10 AlnWater Ratio
Not Used In
Regression
KLa=0.12*L
r2 - 0.998
0.89
-t 1 1 I i I i
0.01
3—2 — 1
Liquid Loading (m m aec )
0.1
Figure A-5. Mass transfer coefficient vs. liquid loading at Olean NY
on 5/25/82 - Trichloroethylene.
-------
TABLE A-l. PILOT PACKED COLUMN AIR STRIPPING RESI'LTS
OLEAN. NY - MAY 25. 1982
Water Temp. ° 10.5'C; Air Temp. - 20°C
Run
1
Liquid Loading (m3 a"*2 sec'1) 0.035
Liquid Loading (GPM ft~2) 51
Air Loading (m3 m~2 sec"1) 0.34
Air Loading (CFM ft2) 67
Alr:Water Volume Ratio 10
X Removed* 75
Mass Transfer Coeff (sec'1)* 0.014
Tnfluent Concentration (ug/1)* 174
Effluent Concentration (ug/1)* 4'.
2
0.026
38
C.43
85
16
87
0.014
173
22
3
0.020
29
0.49
96
24
93
0.012
175
12
4
0.014
20
0.66
130
48
96.8
0.0096
177
5.7
5
0.0082
12
0.72
140
88
98.9
0.0072
192
2.1
6
0.0050
7.4
0.74
145
150
99.6
0.0052
207
0.8
*Based on curve fitting 9 or more data paints.
-------
TABLE A-2. PACKED COL'JKJ AIR STRIPPING DESIGNS
5 cm (2 In.) Plastic Saddles
Packed Column Size
Number of Columns
Column Diameter
Pecking Height
Air Flow
Air Pressure Drop
Economic Estimate
Total Capital
Operating Cost
Production Cost
(K$)
(K$/yr)
(C/1.000 gal)
80
Z TCE Removal
90 95 98
215
27
4.5
245
30
5.3
280
35
5.7
320
40
6.8
99
(ft)
(ft)
(SCFM)
(in H20)
8.8
13.6
5,500
2.8
9.2
19.0
6.400
3.2
9.7
23.2
7,400
3.4
1C
29.7
8,000
3.8
10
35.4
8.000
4.2
350
43
7.2
2.5 cir (1 in.) Plastic Saddles
Packed Column Size
Number of Columns
Column Diameter
Packing Height
Air Flow
Air Pressure Drop
Economic Estimate
Total Capital
Operating Cost
Production Cose
(ft)
(ft)
(SCFM)
(in H20)
I
10.0
12.6
4.000
3.0
1
10.0
18.0
4,000
3.4
2
8.2
19.0
6,400
3.4
2
8.8
22.5
7,700
3.6
2
8.9
25.8
8,200
3.8
(K$)
(KS/yr)
(c/1,000 gal)
230
26
4.b
270
30
5.4
350
32
6.4
410
36
7.3
450
39
7.9
135
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