EPA-600/9-76-015
July 1976
RESIDUAL MANAGEMENT
BY LAND DISPOSAL
Proceedings of the
Hazardous Waste Research Symposium
U.S. ENVIRONMENTAL PROTECTION AGENCY
Cincinnati, Ohio 45268
-------
EPA-600/9-76-015
July 1976
RESIDUAL MANAGEMENT BY LAND DISPOSAL
PROCEEDINGS OF THE HAZARDOUS WASTE RESEARCH SYMPOSIUM
Proceedings of a Research Symposium held at
The University of Arizona, Tucson, Arizona 85721
February 2, 3, and 4, 1976, and Cosponsored by the
U.S. Environmental Protection Agency
Solid and Hazardous Waste Research Division and by
The Department of Soils, Water and Engineering
Agricultural College, The University of Arizona
Edited by Wallace H. Fuller
Department of Soils, Water and Engineering
The University of Arizona
Tucson, Arizona 85721
Project Officer
Robert Landreth
Solid and Hazardous Waste Research Division
Municipal Environmental Research Laboratory
Cincinnati, Ohio 45268
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
CINCINNATI, OHIO 45268
-------
DISCLAIMER
These Proceedings have been reviewed by the
U.S. Environmental Protection Agency and
approved for publication. Approval does not
signify that the contents necessarily reflect
the views and policies of the U.S. Environmental
Protection Agency, nor does mention of trade
names or commercial products constitute
endorsement or recommendation for use.
-------
FOREWORD
The Environmental Protection Agency was created because of increasing
public and government concern about the dangers of pollution to the health
and welfare of the American people. Noxious air, foul water, and spoiled
land are tragic testimony to the deterioration of our natural environment.
The complexity of that environment and the interplay between 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
searching for solutions. The Municipal Environmental Research Laboratory
develops new and improved technology and systems for the prevention, treat-
ment, and management of wastewater and solid and hazardous waste pollutant
discharges from municipal and community sources, for the preservation and
treatment of public drinking water supplies, and to minimize the adverse
economic, social, health, and aesthetic effects of pollution. This publi-
cation is one of the products of that research; a most vital communiciations
link between the researcher and the user community.
The proceedings identify research aimed at minimizing the impact of
disposing of hazardous wastes directly to the land and provides solutions
to unique problems.
Francis T. Mayo
Director
Municipal Environmental
Research Laboratory
-------
PREFACE
The proceedings are primarily intended to disseminate information on extramural
research projects funded by the Solid and Hazardous Waste Research Division
(SHWRD) of the U.S. EPA, Municipal Environmental Research Laboratory in
Cincinnati, Ohio. Selected papers from the programs of other organizations were
included in the symposium either to identify closely related work not included in
the SHWRD program or to present an alternative approach to a problem.
The symposium and the resulting proceedings have two objectives: (1) to dis-
seminate information from ongoing and recently completed SHWRD projects in a
timely fashion and (2) to bring together people who share common interests and who
can benefit from an exchange of research information and views.
Discussion of research projects on an interim basis provide data and information
that could be used by other researchers and the hazardous waste management
industry. The symposium provides a forum for these interim discussions.
Papers in this proceedings are grouped as they were presented in the.sessions
during the symposium. These groupings correspond to improtant aspects of disposal
research and reflect, we think, major areas of interest for government, uni-
versity, and commercial personnel engaged in hazardous waste management or
research.
The first session, "Introduction and Orientation," presented an overview of Federal
research and legislative development programs for hazardous waste disposal.
The second session, "Identification of Pollution Potential," dealt with techniques
for gathering and interpreting information about problems with disposal of
hazardous wastes. Generally, the papers in this session support the need for a
program of disposal research and outline some of the methods currently being used
to gather data on adverse environmental impacts from land disposal of hazardous
wastes.
The third session, "Modification of Disposal Sites and Waste Streams," discussed
some presently available techniques for dealing with potential disposal problems.
Papers in this session focused on preventing the release of contaminants from the
site by chemically altering the waste or the soil and by installing impervious
liners. Additionally, there was discussion of using naturally secure environments
such as salt mines for storage and disposal of hazardous wastes.
The fourth session, "Special Disposal Problems," described studies of specific
wastes which are "special" because they are either unusually concentrated or
contain substances that are hazardous in very low concentrations. Although several
of the studies were specific to one waste, the results are applicable to other
types of waste that were not studied. For example, the work on hexachlorobenzene,
Vinyl chloride, and pesticides will be useful in solving the general problem of
organic waste disposal on land.
In the last session, "Predicting Trace Element Migration," a series of papers were
presented on predicting how contaminants will move in a specific soil and waste. In
addition to discussing predictive and modeling procedures, the papers covered tech-
niques and problems of detecting contaminant movement in soils and of determining the
soil properties and contaminant characteristics which control this movement.
iv
-------
Because knowing how contaminants will move in a given situation is the starting
point for solving the problem of selecting safe land disposal sites, there was
much interest in this area of work. It is not surprising that there were also
some pronounced differences of opinion about the most effective way to model or
predict contaminant movement in soil and about the relative importance of soil
properties in controlling the rate of movement. We think these differences of
opinion are a reflection of the complexity of the soil-waste system and of the
rapidly developing state-of-the-art of dealing with this difficult problem.
Resolution of these differences is expected as work progresses and, particularly,
as conclusions based on laboratory studies are tested against field data.
The papers are printed here as received from the authors and do not necessarily
reflect the policies and opinions of the U.S. Environmental Protection Agency
or the management of this station. We hope that the printing of these proceedings
will enable a wider audience to benefit from the information available and that
these proceedings will stimulate interest in developing safer methods of hazardous
waste disposal on land as well as increased participation in subsequent symposia
on this topic.
-------
ABSTRACT
A research symposium was held to exchange recent information on land disposal of
municipal and hazardous wastes. Papers were presented and compiled into a report on
the following topics:
1. Case studies of actual and potential environmental impact from land disposal
of hazardous wastes;
2. Technology of preventing adverse environmental impact including: (a) process-
ing waste prior to disposal and (b) modification of disposal sites and manage-
ment of disposal operations;
3. Selection of disposal sites to minimize adverse impact;
4. Ameliorating damages at existing disposal sites and suggested modification
of future sites and wastestreams;
5. Identification of pollution potential of selected industrial solid wastes, and
6. Special disposal problems.
The presentations were grouped for convenience into five half-day sessions under
the topics of:
1. Current research (SHWRD) and demonstration projects (OSWMP) on land disposal
and disposal standards and criteria documents involving hazardous wastes;
2. Identification of pollution potential of solid and hazardous wastes;
3. Modification of disposal sites and waste streams;
4. Disposal problems of special industrial hazardous wastes; and
5. Predicting trace element migration through soils.
VI
-------
CONTENTS
Page
Disclaimer ii
Foreword i i i
Preface iv
Acknowledgement vi
Abstract vii
Contents viii
SESSION I: CURRENT RESEARCH (SHWRD) AND DEMONSTRATION PROJECTS (OSWMP) ON
LAND DISPOSAL AND DISPOSAL STANDARDS AND CRITERIA DOCUMENTS
INVOLVING HAZARDOUS WASTES
Moderator: Wallace H. Fuller, University of Arizona
Current Research on Land Disposal of Hazardous Wastes
Norbert B. Schomaker, U.S. Environmental Protection Agency 1
OSWMP Chemical Waste Landfill and Related Projects
Alfred Lindsey, U.S. Environmental Protection Agency 14
Hazardous Waste Guidelines: Plans and Prospects
Walter W. Kovalick, Jr., U.S. Environmental Protection Agency 32
Documentation on Environmental Effects of Pollutants
Allen S. Susten, U.S. Environmental Protection Agency 38
SESSION II: IDENTIFICATION OF POLLUTION POTENTIAL OF
SOLID AND HAZARDOUS WASTES
Moderator: Carl ton C. Wiles, U.S. Environmental Protection Agency
Hazardous Waste Sampling
Robert D. Stephens, California Department of Health 45
The Effects of the Disposal of Industrial Waste Within a
Sanitary Landfill Environment
David R. Streng, Systems Technology Corporation 51
Practical Recommendations for Oil Spill Debris Disposal: A Progress Report
John S. Farlow, U.S. Environmental Protection Agency 71
Industrial Hazardous Waste Migration Potential
Martin Houle, Dugway Proving Ground 76
Field Survey of Solid Waste Disposal Sites: A Preliminary Report
B. L. Folsom, Jr., Waterways Experiment Station 86
Field Verification of Hazardous Industrial Waste
Migration from Land Disposal Sites
James P- Gibb, Illinois State Water Survey 94
vii
-------
SESSION III: MODIFICATION OF DISPOSAL SITES AND WASTE STREAMS
Moderator: Robert Landreth, U.S. Environmental Protection Agency
Evaluation of Selected Liners When Exposed to Hazardous Wastes -, Q2
Henry E. Haxo, Jr., Matrecon, Inc .......................
Liners for Disposal Sites to Retard Migration of Pollutants
Wallace H. Fuller, University of Arizona
Leachability and Physical Properties of Chemically Stabilized Hazardous Wastes
Jerome L. Mahloch, Waterways Experiment Station ...............
A Polymeric Cementing and Encapsulating Process for Managing Hazardous Waste IOQ-
H. R. Lubowitz, TRW Systems Group ......................
An Evaluation of Storing Nonradioactive Hazardous Waste in Mined Openings
Carlton C. Wiles, U.S. Environmental Protection Agency ........... 151
Evaluation of Selected Sorbents for the Removal of Contaminants
in Leachate from Industrial Sludges
John W. Liskowitz, New Jersey Institute of Technology ............ 162
SESSION IV: DISPOSAL PROBLEMS OF SPECIAL INDUSTRIAL HAZARDOUS WASTES
Moderator: Mike Roulier, U.S. Environmental Protection Agency
Problems Associated with the Land Disposal of Organic Industrial
Hazardous Waste Containing HCB
Walter J. Farmer, University of California .................. 177
A Preliminary Examination of Vinyl Chloride Emissions from
Polymerization Sludges, During Handling and Land Disposal
Richard A. Markle, Battelle Columbus Laboratories .............. 186
Disposal of Waste Oil Re-refining Residues by Land Farming
H. J. Snyder, Jr., U.S. Environmental Protection Agency
Behavior of High Pesticide Concentrations in Soil Water Systems
James M. Davidson, University of Florida ..... .............. 206
The Mobility of Three Cyanide Forms in Soils
Bruno Alesii, University of Arizona ..................... 213
SESSION V: PREDICTING TRACE ELEMENT MIGRATION THROUGH SOILS
Moderator: Norbert B. Schomaker, U.S. Environmental Protection Agency
Contaminant Attenuation - Dispersed Soil Studies
op n
Frank A. Rovers, University of Ottawa .................... c^
Estimation of Nonreactive and Reactive Solute Front Location in Soils
P. S. C. Rao, University of Florida ..................... 235
Trace Element Migration in Soils: Desorption of Attenuated Ions and Effects
of Solution Flux
Nic Korte, University of Arizona ....................... 243
Effect of pH on Removal of Heavy Metals from Leachates by Clay Minerals
Robert A. Griffin, Illinois State Geological Survey ............. 259
Development of a Computer Simulation Model for Predicting Trace
Element Attenuation in Soils
Joe Skopp, University of Arizona ....................... 269
viii
-------
ACKNOWLEDGMENT
In addition to the contribution of these, the following
monitors, Allen S. Susten, Norbert B. Schomaker, Michael
H. Roulier, and Robert Landreth (U.S. EPA, Solid and
Hazardous Waste Research Division, Cincinnati, OH); the
generous assistance of the Tucson Convention Bureau; the
program projectionists and lighting engineers, Bruno Alesii
and Juan Artiola; the stenographer and receptionist, Gwen
Pearl; the support provided by the department head of Soils,
Water and Engineering, University of Arizona, Dr. Kenneth
K. Barnes, and finally, the U.S. Environmental Protection
Agency and the University of Arizona for financial, personnel
and physical resources assistance which made this research
symposium a reality.
-------
CURRENT RESEARCH ON LAND DISPOSAL OF HAZARDOUS WASTES
N. B. Schomaker
U.S. Environmental Protection Agency
26 West St. Clair Street
Cincinnati, Ohio 45268
ABSTRACT
The Solid and Hazardous Waste Research Division (SHWRD), Municipal Environmental
Research Laboratory, U.S. Environmental Protection Agency, in Cincinnati, Ohio, has
responsibility for research in the areas of solid and hazardous waste management, in-
cluding both disposal and processing. This research is being directed towards new and
improved systems of solid and hazardous waste management, development of technology,
determination of environmental effects, and collection of data necessary for the
establishment of processing and disposal guidelines. In the past, the Division concen-
trated on problems associated with municipal solid wastes, but over the recent years
the emphasis has shifted more toward hazardous waste management, and disposal alone and
in combination with municipal wastes.
SHWRD has divided its hazardous waste research program into two general areas:
(a) Disposal of Hazardous Residuals to the Land, and (b) Hazardous Waste Materials Treat-
ment. This paper will discuss the overall hazardous waste research program, realizing
that this research symposium is primarily directed toward the land disposal aspects of
hazardous residuals. SHWRD has basically classified its current hazardous waste research
program into six categorical areas shown below:
1. Identification and Characterization of Hazardous Waste
2. Hazardous Waste Decomposition
3. Pollutant Migration Through Soils
4. Control Technology
5. Specialized Wastes
6. Alternatives for Hazardous Waste Landfills
INTRODUCTION
Increasing amounts of hazardous and
toxic wastes are being directed to the
land for disposal by landfill ing. At the
same time, there is increasing evidence of
environmental damage resulting from im-
proper operation. The burden of operating
landfills and coping with any resulting
damages falls most heavily on municipali-
ties and other local government agencies.
Their problems are complex, involving
legislation, economics, and public atti-
tudes as well as technology; additionally,
comprehensive information on how to land-
fill and protect the local environment is
not readily available.
Part of the long range solution to
this problem will be design and operation
manuals, to be published by the Municipal
Environmental Research Laboratory, des-
cribing recommended procedures and tech-
nology for minimizing the impact from
landfill ing of strictly municipal wastes
as well as hazardous and toxic wastes.
Although these manuals will not be pub-
lished until about 1980, a series of inter-
mediate reports will be published,
-------
detailing present and future research
findings that will be incorporated into
the final design and operation manuals.
This paper describes seven current proj-
ects supporting the development of these
manuals.
IDENTIFICATION AND CHARACTERIZATION
OF HAZARDOUS WASTES
Environmental Effects Documents
This research (1) is being performed
to provide human health and environmental
effects as they may relate to the manage-
ment and land disposal of selected haz-
ardous substances/wastes, thus providing
a data base that summarizes, assesses, and
interprets health and ecological effects
of specific hazardous wastes. The haz-
ardous waste environmental effects docu-
ments will contain:
Comprehensive effects data for:
—all forms of life, both human
and other living organisms, for
the air, water, and land
Environmental aspects of hazardous
materials for:
—environmental distribution
--transport through soil; through
soil to water or air; and
through water or air to humans
or other organisms
--transformation
— fate
—accumulation and magnification
These documents are currently being
developed for the following hazardous
materials and related compounds:
arsenic
asbestos
benzidine
beryllium
cadmium
chromium
cyanides
endrin
fluorides
lead
mercury
methyl/parathion
PCB's
toxaphene
Several previous reviews* of these efforts
have been presented.
Standard Sampling Techniques
Standard sampling procedures (2),
including collection, preservation, and
storage of samples, do not exist for solid
and semi-solid wastes. Hazardous wastes,
both at the point of generation and the
point of disposal, are not homogenous mix-
tures and, additionally, may range in con-
sistency from a liquid, through a pumpable
sludge, to a nonpumpable solid. Existing
procedures for sampling liquid effluents
and soils will have application but must
be adapted to a variety of circumstances
and, more importantly, field tested exten-
sively before they can be advocated as
"the" way to sample. Experience with
sampling procedures is being accumulated
as part of several on-going SHWRD projects
and our initial effort in this area relates
to the chemical composition, physical char-
acteristics, and origin of hazardous wastes
delivered to several Class I (hazardous
chemical) landfills in the State of
California.
Standard Analytical Techniques
Assuming that a representative sample
can be taken from a hazardous waste, the
next problem is to analyze the waste.
Existing instrumentation functions well on
simple mixtures at low concentrations but
encounters interference problems with com-
plex mixtures containing materials at high
concentrations (a percent by weight and
greater). In this range the sample cannot
be analyzed directly but must be diluted.
Options here are the development of stand-
ard procedures for diluting and accounting
for errors introduced thereby or, develop-
ment of instrumentation capable of accu-
rate, direct measurements at high concen-
trations in the presence of potential mul-
tiple interferences. Existing EPA proce-
dures for drinking water and liquid
effluents are often not applicable. Ana-
lytical procedures are being developed on
*Schomaker, N. B., and Roulier, M. H.,
Current EPA Research Activities in Solid
Waste Management: Research Symposium on
Gas and Leachate from Landfills: Forma-
tion, Collection and Treatment. March 25-
26, 1975, Rutgers, State University of
New Jersey.
-------
an as-needed basis as part of the SHWRD
projects. However, most of this work is
specific to the wastes being studied and a
separate effort is required to ensure that
more general procedures/equipment will be
developed. A compilation of analytical
techniques (2) used for hazardous waste
analysis is planned for award later this
fiscal year.
Standard Leaching Techniques
Because environmental impact cannot
occur until contaminants are released from
a waste, a standard leaching test is needed
to assess potential contaminant release
from a waste. Such a test must provide
information on the initial release of con-
taminants from a waste when it is contacted
not only with water but with other solvents
which could be brought for disposal. Addi-
tionally, such a test must provide some
estimate of the behavior of the waste under
extended leaching. Experience from on-
going SHWRD projects indicates that some
wastes may initially release only small
amounts of contaminants but, under extended
leaching, will release much higher concen-
trations. Such leaching behavior has an
impact on disposal regulation and on man-
agement of a disposal site and information
on this behavior must be obtained as part
of the process of classifying a waste. The
Office of Solid Waste Management Programs
(OSWMP) has funded an Industrial Environ-
mental Research Laboratory (IERL) proj-
ect (3) to examine this area and develop
procedures for determining whether a waste
contains contaminants in significant con-
centrations and whether a waste will re-
lease such contaminants under a variety of
leaching conditions. Work on extended
leaching is not planned as part of the
project.
HAZARDOUS WASTE DECOMPOSITION
Waste Leachability
In lieu of the development of a
Standard Leaching Technique, one current
on-going hazardous waste leaching study (4)
has been patterned after a method developed
by the International Atomic Energy Agency
(I.A.E.A.) for leach testing immobilized
radioactive waste solids. Plexiglass
columns of 0.35 cubic feet are loaded with
the sample and a 1-inch head of leaching
fluid is maintained on top of the samples.
Two leaching fluids are used, deionized
water and deionized water at a pH of 7.5 -
8.0. The two leaching fluids represent
both sides of the pH scale since the
deionized water will assume an acid pH due
to its reaction with carbon dioxide. The
selection of leaching fluids should provide
some concept of the pH effect on leaching.
Flow through the column is regulated to
maintain a velocity of approximately
1 x 105 cm/sec, and leachate samples are
collected at the base of the column. The
columns are translucent and observations
of flow patterns as well as possible bio-
logical activity can be made. Five in-
dustrial sludges and five Flue Gas Desul-
furization (FGD) sludges are being
investigated.
Another on-going Teachability study
(5) relates to the inorganic industrial
waste where there is no appreciable bio-
logical activity. Consequently, the chief
mode of decomposition and pollutant release
is solubilization and other strictly chemi-
cal changes which take place as the waste
is leached with water. Accordingly, the
testing program is designed to evaluate
leaching and pollutant release under a
variety of leaching conditions which may
be encountered in one or more disposal
situations.
A major consideration in the leaching
behavior of wastes is the pH. Conse-
quently, three types of leaching tests
similar to the one described above, are
being utilized with leaching fluids at
pH 5, 7, and 9 by mixing a sample of the
waste with water and adding a mineral acid,
as required to achieve the desired pH. The
solution is then filtered and the contami-
nant concentration in the liquid phase is
measured. A fourth type of leaching is
conducted by mixing a sample of waste with
deionized water and allowing the waste it-
self to control the pH; this type of
leaching, simulates the action of rainfall
or other water while the pH-adjusted
Teachings simulate the effect of the co-
disposal with strongly acid or alkaline
wastes, or of disposal on soils of those
pH's. A fifth type of leaching is con-
ducted using municipal landfill leachate
as the solvent. This highly odorous
material contains many organic acids and
is strongly buffered at a pH of about 5.
Consequently, it has proved to be a very
effective solvent. This type of leaching
is carried out to simulate co-disposal of
municipal and industrial wastes.
-------
A second major consideration in the
leaching behavior of wastes is time. Some
wastes will not release appreciable amounts
of contaminants until leaching has removed
salinity or reserve alkalinity from the
waste. Accordingly, each of the five types
of leaching is extended over time. After
the liquid has been in contact with the
waste for 72 hours (agitated gently), the
liquid is filtered off and a fresh volume
of liquid is added. This process is re-
peated seven times, each time for a contact
period of 72 hours. Results to date have
indicated great variability in the time-
dependent leaching behavior of wastes, con-
firming the need for careful consideration
of this variable in managing land disposal.
Co-Disposal
Environmental effects from landfill ing
result from not only the soluble and slowly
soluble materials placed in the landfill,
but also the products of chemical and
microbiological transformations. These
transformations should be a consideration
in management of a landfill to the extent
that they can be predicted or influenced
by disposal operations.
One current project (6) supporting
development of the landfill design and
operation manuals is a study of factors
influencing (a) the rate of decomposition
of solid waste in a sanitary landfill, (b)
the quantity and quality of gases and
leachate produced during decomposition,
and (c) the effect of admixing industrial
sludges and sewage sludge with municipal
refuse. Seven industrial sludges and
sewage sludge in three different amounts
have been added to the simulated landfill
test cells to evaluate the impact of a
practice which, though opposed by EPA, is
apparently prevalent in the United States
as a method of disposal for hazardous
wastes. Presently, little is known on
what effect adding sludge has on the de-
composition process, and quantity and
quality of gases and leachate produced
during decomposition. There is a strong
concern that addition of sludges, particu-
larly those high in trace and heavy metals,
will result in elevated metal concentra-
tions in the leachates and will pose a
threat to potable groundwater supplies.
Advocates of co-disposal of sludges with
municipal waste believe that presence of
organics in the landfill will immobilize
trace and heavy metals and, further, that
the presence of such sludges may accelerate
the decomposition process and shorten the
time required for biological stabilization
of the refuse. Periodic analysis of the
leachates in this study for trace and heavy
metals is expected to provide answers to
some of these questions and to allow
rational evaluation of the practice of co-
disposal .
Poliovirus (6) was also added to one
of the simulated landfill cells and the
leachates from all cells are being assayed
for fecal coliform and fecal streptococci
to study the potential health impacts of
landfill ing. It has been assumed that the
environment within a landfill is generally
antagonistic to pathogenic organisms, and
poliovirus has been shown in vitro to have
a very low survival in landfill leachates.
However, other studies have demonstrated
the presence of poliovirus in leachate when
municipal solid waste has been leached
rapidly, and fecal streptococci have been
found over long periods of time in landfill
leachates. Fecal coliforms were also pres-
ent, but their numbers in leachate de-
creased considerably within several months
after placement of refuse.
POLLUTANT MIGRATION THROUGH SOILS
Present management of land disposal of
hazardous wastes is frequently inadequate.
Significant environmental impacts from such
activities are not mere possibilities--
actual damages to groundwater have occurred
and are well documented. Although the po-
tential for damage in general can be
demonstrated, migration patterns of con-
taminants and consequent damages which
would result from unrestricted landfill ing
at specific sites cannot be predicted
accurately. The ability to do this must
be developed in order to justify the re-
quirement for changes in the design and
operation of disposal sites, particularly
for any restriction of co-disposal. Conse-
quently, a significant number of the re-
search projects funded by SHWRD are focused
on understanding the process and predicting
the extent of migration of contaminants
(chiefly heavy metals) from land disposal
sites for municipal and hazardous wastes.
This research is:
--studying migration of hazardous
materials in soils,
—documenting movement of such
materials to establish the link
-------
to health/environmental effects,
--establishing role of soil in con-
trolling or reducing the amount of
harmful substances reaching water
or air.
These pollutant migration studies are being
performed simultaneously in the areas of
(a) industrial hazardous wastes, (b)
municipal refuse, and (c) specialized
wastes. Several previous reviews* of these
efforts have been presented.
Bibliography and State-of-the-Art
The initial effort (5) in this area
resulted in a bibliography relating to the
disposal of hazardous wastes, other than
sewage sludge, on land. It comprises the
results of a search of recent literature
and includes information on the transport,
transformation, and soil retention of
arsenic, asbestos, beryllium, cadmium,
chromium, copper, cyanide, lead, mercury,
selenium, zinc, halogenated hydrocarbons,
pesticides, and other hazardous substances.
In order to limit the size of the resulting
publication, the literature search focused
on processes directly related to transport
(adsorption, ion exchange, etc.) and docu-
mentation of the occurrence and extent of
transport while specifically excluding
topics such as uptake and translocation by
plants, theoretical modeling, and effects
on microorganisms and processes mediated
by microorganisms. The bibliography has
been divided into two volumes to facilitate
its use; the pesticides citations have been
placed in a separate volume and detailed
information on chemical nomenclature and
structures of pesticides appended to this
volume.
The second effort (5) relates to a
"state-of-the-art" document on migration
through soil of potentially hazardous pol-
lutants contained in leachates from waste
materials. The document presents a criti-
cal review of the literature pertinent to
biological chemical, and physical reac-
tions, and mechanisms of attenuation
*Roulier, M. H. Research on Minimizing
Environmental Impact from Landfill ing;
Research on Contaminant Movement in Soils.
Presented at a meeting of the NATO Com-
mittee for Challenges to Modern Society,
Project Landfill. Oct. 20-23, 1975,
London, England.
(decrease in the maximum concentration for
some fixed time as distance traveled) of
selected elements such as arsenic, beryl-
lium, cadmium, chromium, copper, iron,
mercury, lead, selenium, and zinc, along
with asbestos and cyanide in soil systems.
Controlled Lab Studies
This initial effort (5) is examining
the factors which attenuate contaminants
(limit contaminant transport) in leachate
from municipal solid waste landfills.
Although the work is strongly oriented
toward problems with disposal of strictly
municipal wastes, the impact of co-disposal
of municipal and hazardous wastes is also
considered. The project is concerned with
contaminants normally present in leachates
from municipal solid waste landfills and
with contaminants that are introduced or
increased in concentration by co-disposal
of hazardous wastes. These contaminants
are: arsenic, beryllium, cadmium, chromi-
um, copper, cyanide, iron, mercury, lead,
nickel, selenium, vanadium, and zinc.
The general approach was to pass
municipal leachate as a leaching fluid
through columns of well characterized,
whole soils, containing a variety of or-
ganic and inorganic substances, maintained
in a saturated, anaerobic state. The
leaching fluid consisted of typical munici-
pal refuse leachate with high concentra-
tions of metal salts added to achieve a
nominal concentration of 100 mg/1. The
most significant factors were then in-
ferred from correlation of observed migra-
tion rates and known soil and contaminant
characteristics. This effort will con-
tribute to the development of a computer
simulation model for predicting trace ele-
ment attenuation in soils.
The second effort (5) in this area is
studying the removal of contaminants from
landfill leachates by soil clay minerals.
Soil columns were utilized and packed with
mixtures of quartz sand and nearly pure
clay minerals. The leaching fluid con-
sisted of "as is" typical municipal refuse
leachate without metal salt additives.
The general approach to this effort was
similar to that described in the preceding
effort except that (1) both sterilized and
unsterilized leachates were utilized to
examine the effect of microbial activity
on hydraulic conductivity, and (2) exten-
sive studies of the sorotion of
-------
contaminants from leachate on the clay
minerals as a function of pH and the com-
position of leachate were investigated.
The third effort (5) is examining the
potential for contaminant migration from
industrial hazardous wastes disposed of on
land. After the composition and leach-
ability of a waste has been established, a
leachate from the waste is applied to col-
umns of various soils in the laboratory to
allow study of rates of movement of con-
taminants. Wastes are being studied or are
scheduled for study from the following
industries:
Electroplating
Inorganic pigments
Water-based paints
Nickel-cadmium batteries
Chlorine
Lead-acid batteries
Carbon-zinc primary batteries
Hydrofluoric acid
Phosphorous
Aluminum fluoride
Titanium pigments
Re-refining of used petroleum
Flue Gas Desulfurization (FGD)
Because of the chemical complexity of haz-
ardous wastes, it is not possible to simu-
late them; actual wastes are being col-
lected and used in the project. Many of
these wastes are being disposed of with
municipal wastes. To assess the potential
adverse effects of co-disposal, the in-
dustrial wastes are leached with municipal
landfill leachate as well as water. Re-
sults to date indicate that when compared
with water, municipal landfill leachate
solubilizes greater amounts of metals from
the wastes and promotes more rapid migra-
tion of metals through soil. The soils
being used in this study are similar to
those being investigated by the above des-
cribed activities. It is anticipated that
during the life of this effort, studies
will be conducted on 43 industrial wastes,
3 types of coal flyash, and 6 sludges gen-
erated by the removal of sulfur oxides
from the flue gases of coal-burning power
plants.
The fourth effort (5) is a laboratory
study of the migration and degradation in
soil of the pesticides Methyl Parathion,
2,4-D, Atrazine, Trifluralin, and Terbacil
applied at concentrations much higher than
those used in normal agricultural practice.
The intent of the project is to supply in-
formation applicable to problems encoun-
tered in land disposal of pesticides and
solutions from the washing of pesticide
application equipment. Such information
is presently lacking because most work to
date has been conducted from an agricul-
tural rather than a disposal point of view
and very low application rates have been
used. The project includes work on
adsorption-desorption, chemical-microbial
degradation, production of metabolites, and
soil column studies of migration rates.
Data collected during the study will also
be used to test the applicability (at high
concentrations) of existing pesticide mi-
gration models in predicting the rate and
extent of movement through soil. Work on
this project has only recently been ini-
tiated and no results are available.
Field Verification
The initial effort (5) is to test
current assumptions about the effectiveness
of clays and other fine textured earth
materials in restricting the movement of
contaminants into groundwaters. This work
is examining patterns of contaminant migra-
tion around two secondary zinc smelting
plants and an organic chemical manufactur-
ing plant that are storing or disposing of
their wastes on land. The soils in the
area are quite fine textured and, based on
current knowledge of contaminant migration,
should provide safe disposal sites.
The second effort (5) relates to the
use of simulation modeling as one method
of predicting contaminant movement at dis-
posal sites. The two-dimensional model
which was used successfully to study a
chromium contamination problem is being
developed into a three-dimensional model
and will be tested on a well-monitored
landfill where contaminant movement has
already taken place. Although this type
of model presently needs a substantial
amount of input data, it appears promising
for determining contaminant transport
properties of field soils and, eventually,
predicting contaminant movement using a
limited amount of data.
Organic Contaminants
A planned effort (2) to be initiated
this fiscal year relates to organic con-
taminant attenuation by soil. _ Much more
is known about wastes containing inorganic
-------
contaminants than those containing organic
contaminants. Analytical techniques for
inorganic materials are well developed and
relatively cheap compared to analytical
techniques for organic materials which are
both time consuming and expensive. The
problem is compounded by the fact that or-
ganic contaminants are more numerous and
more are being synthesized all the time.
Work on predictive techniques has been
included as a part of all contaminant mi-
gration projects because the results from
this type of work are only useful insofar
as they can be applied to situations which
have not been studied. The results to date
lack generality and no one predictive tech-
nique can be advocated at this time.
CONTROL TECHNOLOGY
Control technology is needed because
experience and case studies have shown
that some soils will not protect ground-
water from contaminants. Even in "good
soil," selected sites may have to be sup-
plemented by additional protection to pre-
vent subsurface pollution from especially
hazardous wastes. To minimize the impact
of placing hazardous wastes in conventional
landfills, treatments under investigation
are directed either at modification of the
waste prior to disposal or modification of
the waste disposal site.
Treatments
Natural Soil Processes:
The treatment of pollutants (5) from haz-
ardous waste and municipal refuse disposal
sites by natural soil processes is basi-
cally being performed under the "Pollutant
Migration Through Soils" studies whereby
various raw soils are being evaluated in
column studies for their pollutant attenu-
ation capabilities. The U.S. Department
of Agriculture (USDA) soils series cur-
rently being investigated are: Anthony,
Ava, Chalmers, Davidson, Fanno, Kalkaska,
Mohave, Molokai, Nicholson, and Wagram.
These soils encompass the range of soil
types—from sand to clays to silts. Other
soils are also being investigated whereby
various percentages of the clay mineral,
kaolinite, montmorillonite, and illite are
mixed with pure sand to form various mix-
tures of sand and clay soils.
Physical/Chemical/Biological:
Recognizing the present inadequacy of
treatment/disposal technology for hazardous
materials, a SHWRD in-house research proj-
ect (4) was initiated that resulted' in a
report describing promising methods for
treating complex waste streams and provide
resource recovery potential. These prom-
ising methods identified were:
Chlorinalysis
Wet air oxidation
Decomposition by acids and bases
Chemical oxidation
Other chemical treatments
Biological degradation
—enzymes
--trickling filters
--activated sludge
Catalysis
Batch and continuous ion exchange
Photochemical processing
Low-temperature microwave discharge
Osmosis/ultrafiltration
Activated carbon absorption
Another in-house study (7) was con-
ducted to determine the impact of hazardous
materials released into the environment.
This study revealed that many of the
materials discharged are persistent or non-
biodegradable, will bioaccumulate in man,
and pose a serious threat to all living
systems.
A number of research efforts have been
initiated to develop and evaluate promising
treatment techniques, previously identi-
fied, for control of hazardous materials.
The initial effort (7) relates to the
chlorinalysis process which appears to be a
very desirable process for eliminating some
very toxic and hard to dispose of chloro-
carbons and pesticide residues. This was a
technical and economic study of the feasi-
bility of converted highly toxic wastes to
carbon tetrachloride and other useful
chemicals. Laboratory studies have con-
firmed that herbicide orange, still bottoms
from organic manufacturing operations, and
pesticides all can be converted to the
principal useful chemical, carbon tetra-
chloride.
A second effort (4) relates to the
investigation of catalytic techniques for
decomposing pesticides and other toxic
wastes to safe, reusable by-products.
Basically, the catalytic hydrogenation of
-------
chlorinated organic compounds is being
studied. While the results of catalysis
are not as favorable as those of chlo-
rinalysis, there is evidence that a cata-
lyst may be discovered that will remove the
group of elements conferring toxicity to a
parent structure, and thereby provide a
feedstock for the synthesis of new useful
chemicals.
A third effort (7) relates to the
assessment of techniques for the detoxifi-
cation of selected hazardous materials.
The existing techniques previously identi-
fied, including hydrogenation, are being
assessed for efficacy and practicality.
This also includes chemical and toxicologi-
cal investigation of all products and
residues provided in the above discussed
incineration or developing detoxification
studies.
A fourth effort (5) relates to a
laboratory evaluation of ten natural and
synthetic materials (bottom ash, flyash,
vermiculite, illite, Ottowa Sand, activated
carbon, kaolinite, natural zeolites, acti-
vated alumina, cullite) for the removal of
contaminants in the leachate and liquid
portion of three different industrial
sludges (calcium fluoride sludge, petroleum
sludge, metal finishing sludge). This in-
vestigation involves beaker studies to
evaluate the static adsorption capacity of
sorbent materials using maximum background
concentrations of contaminants in the
leachate, followed by lysimeter studies to
obtain information regarding the dynamic
absorption capacity and permeability char-
acteristics of these materials. The analy-
sis of the leachate involves the determina-
tion of pH, conductivity, residue, chemical
oxygen demand (COD), total organic carbon
(TOC), anionic species, and cationic spe-
cies before and after contact with sorbent
materials.
Thermal Decomposition:
Treatment by thermal decomposition re-
lates to the establishment of time-
temperature relationships for incinerating
pesticides. Specifically, through the test
program, existing information will be sum-
marized into a state-of-the-art document
and experimental incineration/decomposition
studies will be conducted on approximately
40 pesticides. A lab scale evaluation/
confirmation study and a pilot scale in-
cinerator study are being performed. The
pesticides investigated for thermal de-
composition were:
DDT
Aldrin
Picloram
Ma lathion
Toxaphene
Captan
Zineb
Atrazine
The initial effort (2) relates to the
determination of incineration conditions
necessary for safe disposal of pesticides.
An experimental incinerator was constructed
and utilized to determine the time-
temperature conditions needed for the safe
destruction of pesticides. This research
is being supplemented by another effort
documenting in detail the various research
projects relating to thermal destruction
of pesticides. Efficiencies of combustion,
residence time, and other parameters for
safe incineration were documented.
A second effort (2) relates to the
development of laboratory scale methods
for determining the time-temperature rela-
tionships for the decomposition of pesti-
cides. The successful achievement of this
effort would allow the use of quick labora-
tory test methods to determine best incin-
eration conditions for full-scale destruc-
tion of pesticides.
Isolation
Underground Cavities:
The isolation technology for under-
ground cavities offers attracuive disposal
sites for very concentrated toxic hazardous
wastes. Efforts have been performed to
evaluate the adequacy of:
--deep-well injection (for liquid
waste disposal) including wells and
permeable formations
--salt mines and hard-rock mines for
storage of solid, fixed, or encap-
sulated wastes
The first effort (8) consisted of a
review and analysis of available informa-
tion related to deep-well injection, and
an assessment as to the adequacy of this
method for managing hazardous wastes and
ensuring protection of the environment has
been made. The study provided a compre-
hensive compilation of available informa-
tion regarding the injection of industrial
hazardous waste into deep wells. Limited
-------
assessments made Indicated that deep-well
Injection of selected wastes is environ-
mentally safe provided sound engineering
and geologic practices are followed in con-
structing the well and in operating the
well. Geologic and engineering data are
available in many areas to locate, design,
and operate a deep-well system for inject-
ing hazardous liquid wastes into saline
aquifers (Salaquifers) and other deep
strata. However, there is a paucity of
information on salaquifer chemistry and the
chemical and microbiological reactions of
wastes within a receiving salaquifer.
Federal and state statutes and regulations
vary greatly or are nonexistent to answer
problems arising from the use of interstate
or intrastate aquifers. Regardless of
these identified problems, deep-well injec-
tion remains a viable alternative for waste
management.
The second effort (8) consisted of a
review and analysis of information on the
placement of hazardous waste in mine open-
ings. The study assessed the technical
feasibility of storing nonradioactive haz-
ardous wastes in underground mine openings.
The results showed that a majority of the
wastes considered can be stored underground
in an environmentally acceptable manner if
they are properly treated and container-
ized. Various mine environments in the
United States are applicable for such
storage, room and pillar mines in salt,
potash, and gypsum appear to be the most
favorable. This review concluded that
storage in underground mines is an environ-
mentally acceptable method of managing
hazardous wastes provided the recommended
procedures of site selection, treatment,
concainerization, and waste handling are
followed. The study showed that there now
exists within the United States environ-
mentally suitable underground space for the
storage/disposal of hazardous wastes. Sys-
tems adequate to detect, monitor, and con-
trol waste migration are available or can
be developed from current technology.
Encapsulation:
The encapsulation technology program
is evaluating promising organic and inor-
ganic processes for both fixing and coating
hazardous materials of pesticides, soluble
organics, and heavy oily residues. The
process relates to fixing the material in
a 55-gallon drum or up to a 500-pound block
and then encapsulating the drum or block
with a nonporous plastic coating.
The initial effort (8) relates to or-
ganic process to effectively encapsulate
hard to manage hazardous waste into a
relatively dense mass which will not pol-
lute and could be utilized or disposed in
roadbeds, mines, or fill areas.
Stabilization
Stabilization is achieved by incorpo-
rating the solid and liquid phases of the
waste into a relatively inert matrix which
is responsible for increased physical
strength and which protects the components
of the waste from dissolution by rainfall
or by soil water. If this slows the rate
of release of pollutants from the waste
sufficiently so that no serious stresses
are exerted on the environment around the
disposal site, then the wastes have been
rendered essentially harmless and restric-
tions on where the disposal site may be
located will be minimal.
Chemical Fixation:
The initial chemical fixation effort
(4) relates to the transforming of the
waste into an insoluble or very low solu-
bility form to minimize leaching. The test
program consists of investigating five in-
dustrial waste streams, both in the raw and
fixed state. Each waste stream will be
treated with five separate fixation proc-
esses and subjected to leaching and physi-
cal testing. These lab studies will iden-
tify which processes should be evaluated in
the field by using large scale field plots
or lysimeters. Co-disposal of the fixed
waste with municipal refuse will also be
investigated. The five industrial wastes
being investigated are the same as those
being researched under the pollutant migra-
tion study:
electroplating
chlorine production
nickel-cadmium battery production
inorganic pigment manufacturing
calcium fluoride (electronics)
The following fixation processes will be
utilized with either industrial waste or
flue gas desulfurization waste (SOx). The
assignment of processors to sludge cate-
gories is shown below:
Tl'T L
-Lli '
-------
Processor
Sludge Category
Industrial Waste Flue Gas Desulfurlzatlon
1. International Utilities Conversion
System, Inc. (IUCS)
2. Chem-Fix, Division of Environmental
Sciences
3. Nuclear Engineering Company -- Tiger-
Lok Process
4. Wehran Engineering -- Krete-Rok Process
5. TRW Systems Group, Inc. -- Organic
Binder
6. Lancy Lab
7. Dravo
X
Calcium fluoride only
The second effort (4) will identify
additional stabilization processes that
have potential application to landfilling
of hazardous wastes, study the chemistry
of these processes to eliminate duplication
of work already underway, and then evaluate
selected processes using the procedures
already developed.
The third effort (4) is a series of
field verification studies to assess the
success with which pollutants have been
immobilized at landfills receiving stabi-
lized hazardous and SOx wastes. Detailed
subsurface investigations will identify any
pollutant movement away from such sites and
interactions with soils that have acceler-
ated or retarded such movement. Sites will
be selected to give the widest possible
range of stabilization processes, wastes,
and soils.
Liners/Membranes:
The liner/membrane technology is being
studied to evaluate suitability for elimi-
nating or reducing leachate from landfill
sites of industrial hazardous wastes and
SOx sludge wastes. The test program will
evaluate in a landfill environment, the
chemical resistance and durability of the
liner materials over a 12- and 24-month ex-
posure period to leachates derived from
industrial wastes, SOx wastes, and munici-
pal solid wastes. Acidic, basic, and neu-
tral solutions will be utilized to generate
industrial waste leachates.
• Hazardous Waste Liners—The initial
effort (4) relates to the investigation of
materials for use as liners for hazardous_
waste disposal sites that will be tested in
rectangular, epoxy-coated steel cells (25
cm by 38 cm) containing about 30 cm of the
hazardous waste above the material being
tested. Since the composition of the
leachate from hazardous wastes is deter-
mined mainly by the solubility products of
the components and is not expected to
change significantly over the period of the
experiment, no provision has been included
for drawing leachate from above the liner
material. Any leachate passing through the
liner will be collected and analyzed to de-
termine 'whether there is selective passage
of hazardous substances from the waste. _A
number of materials are under consideration
for study as primary liner materials.
Final selection will be made from the fol-
lowing list:
Polymeric membranes
Butyl rubber
Chlorinated polyethylene (CPE)
Chlorosulfonated polyethylene
(Hypalon)
Ethylene propylene rubber (EPDM)
Neopreme
Polyvinyl chloride (PVC)
3110 (a PVC-type material by DuPont)
Admixed materials
Bentonite clay seal
Emulsified asphalt (Petromat)
10
-------
Soil cement
Hydraulic asphalt concrete
Compacted fine grained soil
Polymeric bentonite sealant
Acid-resistant concrete
Hot sulfur
A second effort (5) relates to a labo-
ratory evaluation of various materials
which could be utilized as retardant mate-
rials to minimize migration of pollutant
from disposal sites. This investigation
will study the following materials on a
pilot plant basis: (a) agricultural lime-
stone, (b) hydrous oxides of Fe (ferrous
sulfate mine waste), (c) lime-sulfur oxide
(stack-gas waste), (d) certain organic
wastes, and (e) soil sealants. Preliminary
research on limestone and Fe hydrous oxide
liners indicates these materials have a
marked retarding influence on many of the
trace elements.
• SOX Sludge Liners--The initial
effort (4) relates to the types of materi-
als to be tested for use as liners for
sites receiving sludges generated by the
removal of sulfur oxides (SOx) from flue
gases of coal-burning power plants which
will be somewhat different from those used
in the municipal and the hazardous waste
studies. The volumes of SOx sludge gen-
erated in any particular place will, typi-
cally, be much greater than those for other
types of wastes, the disposal sites will be
large, and the hazards (Teachable trace and
heavy metals) associated with the sludge
will not be great. Consequently, methods
of lining such disposal sites must have a
low unit cost to be covered. It is desir-
able that the materials be easy to apply.
Because of these considerations, the number
of polymeric membranes included in the
study have been reduced whereas admixed and
sprayed-on materials are being emphasized.
A total of 18 materials/processes will be
selected from the following:
Polymeric
Polyvinyl chloride
Polyethylene
Admixed
Soil cements
Lime stabilized soils
Asphalt cements
Emulsion asphalts
Chemically stabilized SOx sludge
Sprayed-on
DCA 1295
Uniroyal
Dynatech
Plastics
Asphalts
Hot sulfur
SPECIALIZED WASTES
The specialized waste test program re-
lates to hexachlorobenzene, vinyl chloride
monomer, (VCM), and oil spill debris.
--Hexachlorobenzene (HCB) wastes are
being investigated to determine the vola-
tilization aspects of the material and to
evaluate the effectiveness of various mate-
rials for covering these wastes to reduce
volatilization.
--Vinyl Chloride Monomer (VCM) is re-
tained in polyvinyl chloride (PVC) process-
ing sludge wastes. These sludges are being
investigated to determine the amount of VCM
present and the volatilization aspects of
the material.
—Oil Spill Debris disposal from
cleanup efforts is being investigated to
determine the best practicable technical
options available for disposal.
Hexachlorobenzene (HCB)
The initial effort (5) relates to an
evaluation of the effectiveness of the pro-
cedures presently being used to seal HCB
landfills by measuring the rate of movement
of HCB through soil, water, and polyethyl-
ene film. Results of the study, being
conducted under contract, will be used to
specify the conditions, if any, under which
is safe to store or dispose of HCB-contain-
ing wastes on land. The general approach
is to measure the steady state vapor flux
of HCB under laboratory conditions and
then, using Fick's first law, to calculate
the diffusion coefficient for HCB in that
material. Once the diffusion coefficient
is known, the flux through other thick-
nesses of the material can be calculated.
Planned future work on this effort
will examine the effect of soil water con-
tent on the HCB diffusion coefficient and
predicted fluxes through soil and will use
another HCB-contaim'ng waste to verify the
assumption that HCB flux is not affected by
11
-------
other substances present in the wastes
(e.g., hexachlorobutadiene, pentachloro-
benzene).
Vinyl Chloride Monomer (VCM)
The initial effort (9) relates to a
low level study done to determine whether
a potential threat to the health of land-
fill workers or nearby residents exists.
Seventeen grab air samples were collected
for laboratory analysis of VCM content at
three landfills where these sludges were
disposed. Samples of the PVC sludges which
were disposed at the three landfills also
were collected. VCM concentrations in the
grab air and sludge samples were measured
using the gas chromatographic-flame ioniza-
tion detection analytical technique. The
release rate of VCM from sludge also was
measured under controlled laboratory condi-
tions, using a specially designed appara-
tus. The VCM emissions potential of the
total sludge quantities disposed at these
landfills was calculated.
Oil Spill Debris
The initial effort (10) is being per-
formed by the Industrial Environmental
Research Laboratory (IERL) of EPA, OR&D,
and relates to the development of a de-
tailed, practical how-to-do-it manual for
oil spill debris disposal and to the mak-
ing of an accompanying film for State and
local officials. A literature search has
been carried out, sites for confirming
field studies chosen, and some film footage
taken. Present recommendations for dis-
posal of unrecyclable material include in-
dividual burial, incorporation into an
approved sanitary landfill, and land
spreading.
ALTERNATIVES FOR HAZARDOUS
WASTE LANDFILLS
Land Cultivation
The disposal technique of land culti-
vation, whereby specific waste residues
have been directly applied or admixed into
soils, has been an alternate disposal op-
tion for many years for oily waste materi-
als. Since many industrial waste sludges
have similar characteristics to oily waste
materials, it appears that land cultivation
could be viable alternative to landfilling
of hazardous industrial sludges. Conse-
quently, a planned research effort (4) this
fiscal year will prepare a state-of-the-art
document to assess and determine the feasi-
bility and beneficial aspects of land cul-
tivation of hazardous industrial sludges
including oily waste materials. This
state-of-the-art effort would then be fol-
lowed by technical and economic assessment
effort.
CONCLUSION
The laboratory and field research
project efforts discussed here reflect the
SHWRD overall effort in hazardous waste
management research. The projects will be
discussed in much more detail by the fol-
lowing speakers. More information about a
specific project or study can be obtained
by contacting the project officer whose
name, address, and phone number is listed
in this paper. Inquiries can also be di-
rected to the Director, Solid and Hazardous
Waste Research Division, Municipal Environ-
mental Research Laboratory, U.S. Environ-
mental Protection Agency, 26 West St. Clair
Street, Cincinnati, Ohio 45268. Informa-
tion will be provided with the understand-
ing that it is from research in progress
and conclusions may change as techniques
are improved and more complete data become
available.
12
-------
EPA PROJECT OFFICERS
1. Dr. Allan S. Susten, Health Effects
Research Laboratory, U.S. Environ-
mental Protection Agency, 26 West
St. Clair Street, Cincinnati, Ohio
45268. 513/684-7405.
2. Mr. Richard A. Carnes, Municipal Envi-
ronmental Research Laboratory, U.S.
Environmental Protection Agency,
26 West St. Clair Street, Cincinnati,
Ohio 45268. 513/684-7871.
3. Mr. Michael Gruenfeld, Industrial En-
vironmental Research Laboratory, U.S.
Environmental Protection Agency,
Edison, New Jersey 08817.
201/548-3347.
4. Mr. Robert E. Landreth, Municipal En-
vironmental Research Laboratory, U.S.
Environmental Protection Agency,
26 West St. Clair Street, Cincinnati,
Ohio 45268. 513/684-7871.
5. Dr. Mike H. Roulier, Municipal Envi-
ronmental Research Laboratory, U.S.
Environmental Protection Agency,
26 West St. Clair Street, Cincinnati,
Ohio 45268. 513/684-7871.
6. Mr. Dirk R. Brunner, Municipal Envi-
ronmental Research Laboratory, U.S.
Environmental Protection Agency,
26 West St. Clair Street, Cincinnati,
Ohio 45268. 513/684-7871.
7. Mr. Charles J. Rogers, Municipal Envi-
ronmental Research Laboratory, U.S.
Environmental Protection Agency,
26 West St. Clair Street, Cincinnati,
Ohio 45268. 513/684-7881.
8. Mr. Carl ton C. Wiles, Municipal Envi-
ronmental Research Laboratory, U.S.
Environmental Protection Agency,
26 West St. Clair Street, Cincinnati,
Ohio 45268. 513/684-7881.
9. Mr. Donald A. Oberacker, Municipal
Environmental Research Laboratory,
U.S. Environmental Protection Agency,
26 West St. Clair Street, Cincinnati,
Ohio 45268. 513/684-7881.
10. Mr. John S. Farlow, Industrial Envi-
ronmental Research Laboratory, U.S.
Environmental Protection Agency,
Edison, New Jersey 08817. 201/548-3347.
13
-------
OSWMP CHEMICAL WASTE LANDFILL
AND RELATED PROJECTS
Alfred W. Lindsey, Donald Farb, William Sanjour
U.S. EPA
Hazardous Waste Management Division
Office of Solid Waste Management Programs
U.S. Environmental Protection Agency
Washington, D.C. 20460
ABSTRACT
The Office of Solid Waste Management Programs conducts a variety of studies and demon-
strations designed to provide data base and support for the formulation of guidelines for
the treatment and disposal of hazardous wastes. These projects take the form of studies,
analyses, field investigations, and demonstrations. A major undertaking presently being
planned is a study of management options for predicting pollution potential from waste
disposal on land. In another area, the Office's largest single hazardous waste project,
the Chemical Waste Landfill Demonstration is currently getting underway in Minnesota.
This paper discusses the technological and scientific aspects of these two projects. In
addition, tables at the end summarize other OSWMP hazardous waste projects and list Office
reports.
BACKGROUND
Until relatively recently, comparative-
ly little attention has been given to the
disposal of hazardous wastes. However, as
air and water pollution regulations are
implemented, quantities of industrial
sludges, slurries, and liquids, some of
which are toxic or otherwise hazardous, are
increasing rapidly. The Office of Solid
Waste Management Programs (OSWMP) urges
that the following priorities be considered
in managing hazardous wastes:
(1) Recycling,
(2) Material Recovery.
(3) Energy Recovery,
(4) Physically/chemically/or biologically
treat the waste to permit recycling or
recovery,
(5) Incineration,
(6) Treat the waste so as to detoxify it,
(7) Treat the waste so as to immobilize
the hazardous materials or reduce
volume.
(8) Land Disposal
There are a number of processes, techniques,
and equipment designs available for manag-
ing wastes in this manner, but by and large,
wastes have been and continue to be dis-
posed of in a least-cost manner for the
producer/disposer of the wastes. These
least-cost disposal methods are often inade-
quate to protect the environment and the
public health. The methods of treatment
and disposal which are most often used are
landfilling, incineration, and dumping in
pits or lagoons. Land disposal, due to its
relative economy, is the method preferred by
disposers and will likely remain as such
unless regulatory action precludes this
approach. Numerous case histories attest to
groundwater pollution as a result of land
disposal of hazardous and other wastes.1
14
-------
In view of the preference that has been
shown for land disposal, OSWMP is under-
taking several projects to investigate the
adequacy of land disposal technology for
potentially hazardous wastes.
STANDARD ATTENUATION PROCEDURE
It is clear that although a waste may
contain one or more hazardous substances;
whether they pose a groundwater pollution
threat will depend on a variety of factors
including: quantity of waste, leachability,
rainfall, permeability, and attenuative
properties of the soil, and distance to
and quality of the groundwater. In most
cases, it is not known beforehand whether
these site and waste characteristics will
result in pollution. In fact, due to
limited or non-existing monitoring, pollu-
tion incidents are not usually predicted
or known until actual damage has been
experienced. To protect the public health
and the environment it is desirable to
develop a procedure or procedures at any
given site which can (1) evaluate the
potential for groundwater degradation from
potentially hazardous wastes, or (2) det-
ermine whether a harmful (polluting) quan-
tity of waste is involved in a given waste
disposal situation. Ideally, such a tech-
nique could also be used to determine the
maximum safe loading of any waste on or in
any given land parcel. Probably maximum
utility can be realized by use of the
technique as a standard tool in the site
permit decision making process by regula-
tory agencies. As such, it would provide
a uniform, organized approach to decision
making based on site/waste specific data.
Accordingly, OSWMP is embarking upon a
program which may lead to development of
a decision making tool, capable of pre-
dicting groundwater pollution potential
based on the characteristics of the dis-
posal site and the wastes to be disposed.
At the present time it is not clear which
of several possible approaches to devel-
opment of such a procedure is optimum.
That is, should it include a model, a
decision tree, criteria ranking process,
or other methods? It is also not clear to
what extent various techniques have been
developed or perhaps, are in use.
Therefore, as a first step, OSWMP will
determine the state of the development and
evaluate the potential usefulness of
techniques for predicting groundwater
pollution potential from disposal of
specific wastes on specific land parcels.
Objectives are as follows:
1. determine what viable techniques are
in use or under development.
2. assess the potential of possible tech-
niques or approaches (in use or
proposed) for development of a stand-
ard procedure,
3. estimate the costs, work and time
requirements for development of a
working standard procedure for each
viable option, and
4. prepare in detail, a developmental pro-
gram for the technique or combination
of techniques judged to be the best.
The study work period will be nine
months with a final report being published
in about one and one-half (1 1/2) years.
CHEMICAL WASTE LANDFILL DEMONSTRATION
In addition to developing a tool to
assist in evaluating pollution potential,
OSWMP is deeply involved in identifying
and demonstrating alternatives to improper
disposal. One of the alternatives is to
have a regional chemical waste disposal
facility, privately operated but government
owned where the local government provides
facilities for proper disposal and, through
regulation and strict enforcement, prevents
improper disposal within the region.
OSWMP is sponsoring a demonstration of
this approach with a grant to the
Minnesota Pollution Control Agency to
build and operate a chemical waste land-
fill. The objectives of this grant are
to demonstrate:
how local governments can organize and
finance such a venture
regulation and enforcement necessary to
make it work
arrangements for long-term care of the
site
public involvement in hazardous waste
disposal, and
15
-------
existing technology.
Development of information on techno-
logies is of limited value if that infor-
mation is not interpreted and disseminated.
Furthermore, technology alone will have
limited impact if other important issues
such as planning, financing, procuring and
managing are not addressed as well. Dem-
onstrations supported by OSWMP, which in-
stall technology into operating solid
waste management systems, develop the in-
formation needed to assist communities in
decision making. These projects must con-
sider whether the technologies under dem-
onstration are economically viable and can
be transferred to "real-world" situations.
They must be designed to consider not only
the technological efficacy, but how systems
can be adopted by political decision
makers.
An important technological considera-
tion in the concept of this project is to
make land disposal sites suitable for the
receipt of hazardous wastes by carefully
choosing the best site available and by
designing the facility so as to overcome
the shortcomings of the site. Proper
design when coupled with sound management
techniques will also prevent accidents,
fires and explosions, air pollution inci-
dents and other mishaps which are common
in many land disposal sites today.
In dry areas of our country, land
disposal can usually be carried out in a
sound and safe manner using well managed
solar evaporation, soil incorporation, and
trench disposal techniques. However, a
majority of the industrial waste (estima-
ted at 65 percent) is generated in the
humid regions, mostly east of the
Mississippi River. 2 Humid regions are
characterized by annual precipitation
rates that are in excess of annual evapo-
transpiration rates, thus creating a
potential leachate management problem.
Technology concepts for land disposal
of chemical wastes in humid regions have
been developed but never demonstrated on a
commercial scale. Commercial-scale demon-
stration of the environmental adequacy,
economic feasibility, and operating prac-
ticability of a variety of currently pro-
moted land disposal concepts is needed
before workable disposal guidelines and
regulations can be developed.
The technological and scientific
aspects of the project include:
demonstration of site selection methods
demonstration of appropriate site
preparation techniques to prevent
groundwater infiltration
demonstration of monitoring and sur-
veillance techniques
evaluation of waste handling and opera-
tional procedures
determination of costs
evaluation of social and institutional
issues
The proposal submitted by the
Minnesota Pollution Control Agency (PCA)
ranked highest among eight finalists who
submitted formal applications and was
selected for the grant award.3
The grant period is for five years
with a total cost of $5.4 million dollars,
three-quarters ($3.72 million) of which
will be funded by the federal government
and one quarter ($1.69 million) funded by
local sources. The project's implementa-
tion is scheduled as follows: the first
2 1/2 years will be directed to planning,
design, and construction of the facility;
the landfill will open in late 1977 and
operate as a demonstration project until
mid-1980 (Figure 1). It will continue to
serve the region's chemical waste disposal
needs after the demonstration period ends
in 1980.
The PCA has contracted with the
Metropolitan Waste Control Commission
(MWCC), a State chartered regional operat-
ing authority, to implement planning, and
construction of the facility as the manag-
ing agency. The MPCA will oversee the
project, manage public education and
citizen acceptance aspects of the project,
and eliminate improper disposal through
regulation and enforcement. Design and
environmental assessment activities will
be performed by consultants under contract
to the MWCC. Similarly, actual day-to-day
operation will be contracted to a private
firm.
16
-------
Figure 1. Demonstration Period
1st Year
2nd Year
3rd Year
4th Year
5th Year
1.Organize
2.Select Applicant's
subcontractors
3.Select Operator
4.Select Proj. Site
5.Phase I Public r-
Accept. Program t-
6.Arrange Loc. Fund.
7.Purchase Site
8.Phase II Public
Accept. Program
9.Collect Addit.
Backgr. Data
10.Sel.Proc.& Techn.
11.Design Processes
12.Facility Design
13.Envir. Surveillance
Design
14.Permits & Approvals
15.Equip. Purch. &
Delivery
16.Envir.Survel.Constr
17.Collect Backgr.
Envir. Data
18.Facility Constr.
19.Waste Flow Manage-
ment Set-Up
20.Cost Acct. Set-Up
21.Hire&Train Operat.
22.Facility Start-Up
23.Routine Operation
24.Envir.Surveillance
25.Public Education
26.Statewide Haz.
Waste Regulations
27.Statewide Haz.
Waste Inv. & Plan
28.Haz. Waste Transp.
Licensing System
29.Metr.Managem.Syst.
30.Statewide Manage-
ment System
17
-------
For purposes of discussion in this
paper, the demonstration program may be
considered in two parts: proposed sites
and technical design and waste handling
procedures.
Proposed Sites. The site selection
criteria used by the grantee emphasized:
low population density
compatibility with adjacent land uses
close proximity to chemical waste
generators
homogeneous soil well above recorded
high groundwater levels
groundwater discharge areas
adequate water and power supply with
good site access
low flora and fauna diversity
Six sites in the greater Minneapolis/
St. Paul metropolitan area were identified
and subjected to further analysis during
the proposed stage. Additional site eval-
uation studies are planned. As of now,
of the sites investigated, the Flying
Cloud site, a 36-hectare (90-acre) parcel
in Hennepin County, is the site that best
satisfies the selection criteria and is
considered to have the greatest potential
for this demonstration as of this time.
The Flying Cloud site is located immedia-
tely north of the Minnesota River in Eden
Prairie Township in the southwest portion
of the metropolitan Minneapolis/St. Paul
area. It is adjacent to the Flying Cloud
Airport on the north and east and is
accessible by way of U.S. Highway 169-212
(Figure 2). The site is 26 kilometers (16
miles) from the major industrial center of
the region.
Existing land use is quasi-public and
private with open fields and idle cropland.
Low fauna and flora diversity is typical
of such land use, pioneer species of vege-
tation and small animals are most predomi-
nant. Ultimate land use in the vicinity
of the site will be for industrial pur-
poses (Figure 3).
The area is not densely populated.
Peak density during working hours is
approximately 125 people per square mile.
Projected and planned population densities
for the City of Eden Prairie will not be
reached until after the facility has been
closed and such residential development
will not be permitted in the vicinity of
the demonstration facility.
The site is located on a bluff over-
looking the Minnesota River Valley and
well above (50 meters) the river's flood-
plain. The property boundary extends all
the way to the river and, thus includes
the river embankment and floodplain imme-
diately below the bluff. The river embank-
ment and floodplain have been designated as
open space by the City of Eden Prairie and
will be maintained as open space by the
grantee. Construction of the proposed
facility would be on the bluff, well back
from the river embankment. A series of
land-locked surface depressions or glacial
kettles (Figure 4) can be used to control
surface runoff and help assure that the
quality of surface waters is maintained.
Approximately 50 meters (159 feet) of
glacial outwash and grey till deposits
overlie Prairie-du-Chien dolomite (Figure
5). Groundwater in this area, the Prairie-
du-Chien aquifer, is typically 50 meters
(150 feet) below the surface and discharges
to the Minnesota River. The discharge rate
has been estimated to be 1,170 liters (310)
gallons per minute. Although the aquifer
is a source of drinking for residents of
the metropolitan area, drinking water wells
and supply points are located upgradient
(north) of the proposed site. The quality
of the groundwater beneath the site would
be maintained by an environmental fail-safe
design.
Technical Design and Waste Handling
Procedures. The geographic location of
the project and the permeability of the
overburden indicate that leachate migration
and groundwater infiltration from the land-
fill would occur if not for the addition
of impermeable barriers (liners) and
leachate collection systems below each
burial area. Therefore, such precautions
will be absolutely necessary if the pro-
ject's objective to demonstrate land dis-
posal of chemical wastes so as to preclude
leachate migration and groundwater quality
degradation, is to be achieved. To this
end, the Minnesota PCA has proposed three
levels of environmental safeguards to
manage chemical waste leachate. The pri-
mary level of protection will consist of
18
-------
Flood Plain Limits
Commercial and Industrial
Open
Public or Quasi Public
Residential Development
Residential Dwellings
Recreational Area
Parks
Schools
N
0 3000
6000
SCALE IN FEET
FLYING CLOUD SITE
R
P
S
Figure 2. FLYING CLOUD SITE. Existing Land Use.
Source: Barr Engineering Co. Minneapolis3
19
-------
Flood Plain Limits —•——'
Existing Major Road «—«——
Proposed Major Road •••••»
Fire Station
School
Industrial
Residential
Public or
Quasi-Public
Park
Figure 3. FLYING CLOUD SITE. Ultimate Land Use.
Source: Barr Engineering Co. Minneapolis3
N
6000
SCALE IN FEET
FLYING CLOUD SITE
20
-------
Drainage Divides
Direction of Flow
200O'
SCALE IN FEET
FLYING CLOUD SITE
Figure 4. FLYING CLOUD SITE.
Surface Drainage
''Source: Barr Engineering Co. Minneapolis.c
-------
T 0 P S 0 I L
1-20'
0 U T W A S H
100-150'
BEDROCK
Dark brown organic silty fine sand (SM)
in upland areas, 1 to 3 feet.
Brown-black organic silty fine sand,
organic clayey silt and organic silt
(OL-OH) in lowlying areas, 7 to M reel.
Fine to coarse sand with some gravel
(SP or SW).
Fine to medium sand with some gravel
Grey glacial till, clay and silt with
sand and gravel layers.
Data compiled from five soil
borings located in the SE%,
Sec. 27, T.116N. R.22W. and
approximately 3,600 feet
east of the proposed site.
Figure 5. FLYING CLOUD SITE. Typical Soil Profile
Source: Barr Engineering Co. Minneapolis
22
-------
an impermeable synthetic liner (such as
hypalon, polyvinyl chloride, or rubber)
positioned in the bottom of each disposal
cell (Figure 6). This barrier will be
protected by a layer of permeable washed
sand. A network of perforated pipes will
be positioned immediately above the pri-
mary liner to facilitate leachate collec-
tion. A secondary barrier of compacted
colloidal clay will underline the pri-
mary barrier and serve to further protect
the groundwater if the primary barrier
should fail. The secondary barrier will
also be served by a separate leachate
collection network. Discharge wells will
be installed upgradient and downgradient
of the site. These wells will serve as a
third level of protection to control
leachate plume movement in the very un-
likely event that both the primary and
secondary leachate management systems
should simultaneously fail to perform.
The performance of the leachate man-
agement system and groundwater quality
will be monitored at all times. The sur-
veillance program will include suction
lysimeters underneath the secondary bar-
rier, core soil samples around the peri-
meter, and observation wells with con-
tinuously recording pH and conductivity
probes. Groundwater and soil samples will
be collected routinely and subjected to
comprehensive laboratory analyses to
determine the presence of leachate species.
Monitoring will continue after the site is
closed to assure long-term environmental
protection.
Completed waste burial units will be
capped with an impervious liner to mini-
mize further infiltration from precipita-
tion.
Surface runoff will be managed and
collected on-site. No runoff will be dis-
charged from the site without receiving
quality analysis and wastewater treatment,
if necessary. Runoff from uncontaminated
or non-disposal areas will be collected in
lined depressions. Surface runoff from
disposal/treatment areas and leachate
effluents from disposal units will be
collected in separate lined holding basins.
Contaminated effluents will be treated on-
site by physical and chemical treatment
techniques prior to being discharged to
the Blue Lake activated sludge wastewater
treatment plant for final treatment.
Waste from 12 major Standard Indus-
trial Classifications (SIC) are generated
in the Minneapolis/St. Paul area. Fore-
most among these industrial wastes are
electroplating wastes, petroleum refining
wastes, inorganic chemicals manufacturing
wastes, and tannery wastes. Other indus-
trial wastes such as metals mining wastes
which are not immediately available
within the service area, will be imported
in sufficient quantities to demonstrate
their landfilling potential.
The grantee has completed an initial
inventory of waste generated in the service
area and will augment this data with addi-
tional inventory data to formulate the
facility's design engineering plan. The
overall process design proposed by the
Minnesota PCA emphasizes quality control
to assure safe waste handling, treatment,
and disposal (Figure 7). Waste receiving
techniques, including sample analysis,
and storage areas, will assure that non-
compatible wastes are segregated through-
out the entire waste handling, treatment,
and disposal process. Employee health
monitoring programs and safety equipment
will be provided to assure a safe work
environment. For example, chemical fire-
fighting equipment will be available to
control accidental fires.
Chemical waste disposal decisions
will include consideration of the
waste's:
chemical form (inorganic or organic)
persistence
acute or chronic toxicity
genetic effect
flammability/reactivity
Several waste preparation and treatment
techniques have been proposed including:
encapsulation, blending, neutralization,
fixation, and liquid-solids separation
(such as coagulation and flocculation).
These techniques will be further evaluated
during the facility design phase of the
demonstration program. Waste preparation
techniques selection criteria will
emphasize:
23
-------
^.Sloped
Sloped^
COMPACTED COVER MATERIAL Percolation Barriers
CHEMICAL WASTE'
•Primary Waste Control Barriers (membranes, liners)
Leachate Collection System
CLEAN SAND (permeabilities in the range of 1 cm/sec to 10 cm/sec) .'•.•
-'. '.' V- Leachate Collection System ': -^"r-^-^i. .'•'. ..'•'••
////^^//^//'/'COMPACTED COLLOIDAL CLAY '///////
X/////'///(Permeabilities in the Range of 10'9)////// ^
////////////' . -
////////////////
NATURAL SOILS
GROUND WATER
TABLE
Figure 6. Typical cross section through disposal area showing primary and
secondary waste control Barriers
Source: Barr Engineering Co. Minneapolis
24
-------
CHEMICAL WASTE STREAM
z
O
<
o.
ee
a.
1/1
<
a.
O
Inspect, Sample, Label. Weigh,
Assign Flow Route
| Storage | | Storage 1 [ Storage 1 | Storage 1 | Storage 1 | Storage 1 | Storage
pH
-------
economy of scale, i.e., techniques that
have applicability to a broad range of
waste types
. volume reduction to efficiently use
available landfill space and eliminate
initial water content
compatibility to the waste types and
forms generated in the service region
Waste inventories, both storage and
burial inventories, and burial maps will
be maintained by the landfill operator.
With such inventories, it will be feasible
to locate and extract any given waste with
minimal searching. This procedure will
facilitate future waste reclamation or
site repair efforts.
Technical methods, project results
and recommendations will be reported on by
the grantee at the conclusion of the five-
year grant program. Two interim reports,
submitted at the conclusion of the pro-
ject's second year, will discuss:
1. Site selection, site purchase, base-
line data gathering, and licensing
tasks. Initial phases of the citizen
acceptance campaign will also be
discussed.
2. Waste inventory findings, process
selection and design, environmental
surveillance design and other facility
design tasks. The report will also
project the environmental impact of
the facility's design and operational
procedures, including: liner inte-
grity, waste compatibility, leachate
management system effectiveness,
surveillance network effectiveness,
and contingency plans to handle system
failures or spills. This will serve
to update the Environmental Impact
Assessment prepared as part of the
grant application.
All interim and final reports will be
published by EPA and made available.
posal of hazardous wastes. Subject areas
include (1) investigation of pollution
incidents to determine causes and magni-
tude of damages, (2) identification and
quantification of potentially hazardous
wastes, (3) evaluation and demonstration of
adequate treatment and disposal techniques,
and (4) investigation of a variety of im-
plementation oriented issues such as
economic impacts.
Some are demonstration projects like
the Chemical Waste Landfill project. In
addition, two projects have been under-
taken to demonstrate destruction of
hazardous wastes by incineration. Versar,
Incorporated has completed a series of
test burns in which the destruction of DDT
and 2,4,5-T pesticides was demonstrated in
conjunction with the burning of sewage
sludge.^ The demonstration facility was
the multiple hearth municipal sewage treat-
ment facility in Palo Alto, California.
Destruction ratios in excess of 99.9 per-
cent were consistently achieved. A more
ambitious project is now underway in which
sixteen representative industrial wastes
will be test destructed under varying con-
ditions in seven commercial scale inciner-
ators.5 The facilities chosen represent
design variations which are currently
available. The second test sequence is
now underway. Total funding is approxi-
mately 1.5 million dollars. TRW Systems
Group and Arthur D. Little, Incorporated
are handling the sampling and analysis,
and waste acquisition and facility avail-
ability are being subcontracted.
Other projects include contract stu-
dies and field investigations. Table 1
summarizes these programs. Additional
information is available from the Project
Officers. The Appendix identifies OSWMP
sponsored publications on the subject of
hazardous waste management which can be
easily obtained.
OTHER HAZARDOUS WASTE MANAGEMENT PROJECTS
The Office of Solid Waste Management
Programs conducts a variety of studies
and demonstrations designed to provide
data base and support for the formulation
of guidelines for the treatment and dis-
26
-------
TABLE 1. OSWMP HAZARDOUS WASTE PROJECTS
Project
Chemical Waste Landfill
Standard Attenuation Proc.
Incineration Eval.
Treatment Process Analysis
Alternative Treatment Studies
Organic Chemical Industry
Wastes
Petroleum Refinery Wastes
Metals Refining Industry
Wastes
Inorganic Chemicals
Industry Wastes
Pesticide Incineration
Study
Groundwater Sampling Study
Standard Leaching Test
Pesticide Chemical Disposal
Energy Recovery
Capacity Creation, Waste
Industry
Container Landfill Analysis
Economic Analysis, Inorganic
Chemical and Petroleum
Industries
Industry Studies
Primary & Storage Batteries
Industrial Inorganic
Chemicals
Type
Grant
Contract
Contract
Contract
Contract
Contract
Contract
Contract
Contract
Contract
Intra Agency
Contract
Contract
Contract
Contract
Contract
Contract
Contract
Subject
Demo.
Study
Demo.
Study
Study
Study
Study
Study
Demo.
Field
Investigation
Research
Study
Study
Study
Study
Study
Study
Study
Project
Officer
Farb
Lindsey
Schaum
Grumpier
Grumpier
Grumpier
Tarnay
Tarnay
Schaum
Huber
Lazar
Trask
Corson
Kohan
Day
Shannon
Fields
Fields
Contractor
Minnesota
(Not Awarded)
TRW
A.D. Little
(Not Awarded)
(Not Awarded)
(Not Awarded)
(Not Awarded)
Versar
(Not Awarded)
EPA-Edison
TRW
Reynolds, Hill,
E.D. Snell
TRW
A.D. Little
Versar
Versar
Completion
June, 1980
April, 1977
January, 1977
July, 1976
November, 1976
November, 1976
February, 1977
February, 1977
March, 1975
January, 1978
March, 1977
January, 1976
Smith October, 1976
February, 1976
January, 1976
April, 1976
January, 1975
March, 1975
-------
Table 1 Continued
NJ
oo
Project
Industry Studies (cont.)
Pharmaceuticals
Metals Mining
Paint & Allied Products
Petroleum Refining
Organic Chemicals
Electroplating
Primary Metals
Textile Mill Products
Rubber and Plastics
Leather Tanning/Finishing
Special Machinery
Oil Refining
Waste Exchange Analysis
Type
Contract
Contract
Contract
Contract
Contract
Contract
Contract
Contract
Contract
Contract
Contract
Contract
Contract
Subject
Study
Study
Study
Study
Study
Study
Study
Study
Study
Study
Study
Study
Study
Project
Officer
Pearce
Pearce
Straus
Straus
Fields
Straus
Pearce
Straus
Straus
Pearce
Pearce
Straus
Porter
Contractor
A.D. Little
Midwest Research
WAPORA
Jacobs Engineers
TRW
Battelle
Calspan
Versar
F.D. Snell
SCS
WAPORA
(Not Awarded)
A.D. Little
Completion
January, 1976
May, 1976
January, 1976
March, 1976
January, 1976
February, 1976
April, 1976
April, 1976
April, 1976
May, 1976
April, 1976
May, 1976
July, 1976
-------
REFERENCES
1. U.S. Environmental Protection Agency,
Office of Solid Waste Management
Programs. Hazardous waste disposal dam-
age reports. Environmental Protection
Publication SW-151. Washington, U.S.
EPA, June 1975.
2. U.S. Environmental Protection Agency,
Office of Solid Waste Management
Programs. Disposal of hazardous
wastes; report to Congress. Environ-
mental Protection Publication SW-115.
Washington, U.S. Government Printing
Office, 1974. 110 p.
3. State of Minnesota demonstration grant
application - chemical waste land
disposal facility. Minneapolis, Barr
Engineering Co., 1975. 286 p.
4. Whitmore, F.C., and R.L. Durfee. A
study of pesticide disposal in a
Sewage sludge incinerator. Unpublish-
ed report to the Environmental Protec-
tion Agency. Springfield, Va., Versar
Inc., 1975. 174 p.
5. TRW Systems, Inc. Destructing chemical
wastes in commercial scale incinera-
tors; technical summary. Unpublished
report to the Environmental Protec-
tion Agency. Redondo Beach, Ca., TRW
Systems, Inc., July 1975. 139 p.
29
-------
APPENDIX 10.
HAZARDOUS WASTE PUBLICATIONS
Disposal of Hazardous Wastes; Report to 11.
Congress. U.S. EPA, Office of Solid
Waste Management Programs. Environ-
mental Protection Publication SW-115.
Washington, U.S. Government Printing
Office, 1974. 110 p. Available from
OSWMP (#345).* 12.
Federal Program for Hazardous Waste
Management. J.P. Lehman. Waste Age,
5(6):6-7, 66-68, Sept. 1974. Available
from OSWMP (#399).
Hazardous Wastes. Environmental Protec-
tion Publication SW-138. Washington,
U.S. Government Printing Office, 1975. 13.
24 p. Available from OSWMP (#450).
Environmental Information; Hazardous
Wastes and their Management. Washington,
U.S. Environmental Protection Agency,
May 1975. 3 p. Available from OSWMP
(#452).
Pesticides; EPA Proposal on Disposal 14.
and Storage. Federal Register, 39(200):
3687-36950, Oct. 15, 1974. Available
from OSWMP (#398).
Where Have All the Toxic Chemicals Gone? 15.
W.H. Walker. Ground Water, 11(2):11-20,
Mar.-Apr., 1973. Available from OSWMP
(#415).
One Private Plant Treats Oil, Chemical
Residues in Denmark. P. Henriksen. 16.
Solid Waste Management, 17(5):77-78,
139, May 1974. Available from OSWMP
(#418).
Incineration in Hazardous Waste Manage-
ment. A.C. Scurlock, A.W. Lindsey, T.
Fields, Jr., and D.R. Huber. Environ-
mental Protection Publication SW-141.
Washington, U.S. EPA, 1975. 104 p.
Available from OSWMP (#427).
Hazardous Waste Management Facilities
in the United States. A.J. Hayes. En-
vironmental Protection Publication SW-
146. Washington, U.S. EPA, Dec. 1974.
39 p. Available from OSWMP (#429).
Hazardous Waste Disposal Damage Reports.
Environmental Protection Publication
SW-151. Washington, U.S. EPA, June 1975.
8 p. Available from OSWMP (#449).
Industrial Waste Management; Seven Con-
ference Papers. Environmental Protec-
tion Publication SW-156. Washington,
U.S. EPA, Feb. 1975. Ill p. Available
from OSWMP (#453).
Organic Pesticides and Pesticide Con-
tainers; A study of their Decontamina-
tion and Combustion. R.C. Putnam, F.
Ellison, R. Protzmann, and J. Helonsky.
Environmental Protection Publication
SW-21c. U.S. EPA, 1971. 175 p. Avail-
able from NTIS (#PB-202 202). Cost
$6.25.
A Study of Hazardous Waste Materials,
Hazardous Effects and Disposal Methods.
Booz Allen Applied Research, Incorpor-
ated, U.S. EPA, 1973. 3v. (vol. 1 - 408
p., vol. 2 - 544 p., vol. 3 - 400 p.).
Available from NTIS (//PB-221 465 -
$10.50, #PB-221 466 - $12.50, #PB-221
467 - $11.50.
Tentative Procedure Analyzing Pesticide
Residues in Solid Waste. R.A. Carnes.
U.S. EPA, 1972. 23 p. Available from
NTIS (PB-222 165). Cost $3.25.
Public Attitudes Towards Hazardous
Waste Disposal Facilities. L.L.
Lackey et al. U.S. EPA, 1973. 181 p.
Available from NTIS (#PB-223 638).
Cost $7.00.
Recommended methods of reduction, neu-
tralization, recovery or disposal of
hazardous waste. R.S. Ottinger et al.
U.S. EPA, 1973. 16 v. Available from
NTIS.
PB-224 580 v.l. Summary report. 210 p.
($7.25)
PB-224 581 v.2. Toxicologic summary.
224 p. ($7.50)
PB-224 582 v.3. Ultimate incineration.
251 p. ($8.50)
PB-224 583 v.4. Miscellaneous waste
treatment processes. 149 p.
($5.75)
PB-224 584 v.5. Pesticides and cyanide
compounds. 146 p. ($5.75)
* Shelf number
30
-------
PB-224 585 v.6. Mercury, arsenic, chromium
and cadmium compounds. 207 p.
($7.25)
PB-224 586 v.7. Propellants, explosives,
and chemical warfare material. 266
p. ($7.50)
PB-224 587 v.8. Miscellaneous inorganic
and organic compounds. 79 p. ($4.75)
PB-224 588 v.9. Radioactive materials. 168
p. ($6.25)
PB-224 589 v.10. Organic compounds. 316 p.
($9.25)
PB-224 590 v.ll. Organic compounds (con-
tinued). 247 p. ($7.50)
PB-224 591 v.12. Inorganic compounds. 330
p. ($9.50)
PB-224 592 v.13. Inorganic compounds (con-
tinued). 290 p. ($8.75)
PB-224 593 v.14. Summary of waste origins.
160 p. ($6.25)
PB-224 594 v.15. Research and development
plans. 109 p. ($5.25)
PB-224 595 v.16. References. 424 p.
($10.50)
17. Alternatives to the Management of
Hazardous Wastes at National Disposal
Sites. Arthur D. Little, Inc. Envi-
ronmental Protection Publication SW-
46c. U.S. EPA, 1973. 85 p. Available
from NTIS (#PB-225 164). Cost $4.75.
18. Program fro the Management of Hazard-
ous Wastes. Battelle Memorial Insti-
tute. U.S. EPA, 1974. 2 v. (Vol. 1 -
385 p., vol. 2 - 778 p.). Available
from NTIS (#PB-233 630 - $10.25,
#PB-233 631 - $17.25).
19. Promising Technologies for Treatment
of Hazardous Wastes. R. Landreth and
C. Rogers. U.S. EPA, 1974. 44 p.
Available from NTIS (#PB-238 145) .
Cost $3.75.
20. Assessment of Industrial Hazardous
Waste Practices, Storage and Primary
Batteries Industries. Versar, Inc.
Environmental Protection Publication
SW-102c. U.S. EPA, Jan. 1975. 209 p.
Available from NTIS (#PB-241 204).
Cost $7.25.
21. Assessment of Industrial Hazardous
Waste Practices, Inorganic Chemicals
Industry. Versar, Inc. U.S. EPA,
Sept. 1975. Available from NTIS (#PB-
244 832). Cost $12.25.
22. State Program Implementation Guide:
Hazardous Waste Surveys. C.H. Porter.
Environmental Protection Publication
SW-160. Washington, U.S. EPA, July 1975
38 p. Available from OSWMP (#464).
23. Information About Hazardous Waste Man-
agement Facilities. D. Farb and S.D.
Ward. Environmental Protection Publi-
cation SW-145. Washington, U.S. EPA,
July 1975. 130 p. Available from
OSWMP (//468) .
24. Tetrachlorodibenzodioxin: An Acciden-
tal Poisoning Episode in Horse Arenas.
C.D. Carter, R.D. Kimbrough, J.A.
Liddle, R.E. Cline, M.M. Zack, Jr., W.
F. Barthel, R.E. Koehler, and P.E.
Phillips. Science 188(4189):738-740,
May 16, 1975. Available from OSWMP
(#474).
25. Landfill Disposal of Hazardous Wastes:
A Review of Literature and Known Ap-
proaches. T. Fields, Jr. and A.W.
Lindsey. Environmental Protection
Publication SW-165. Washington, U.S.
EPA, Sept. 1975, 36 p. Available from
OSWMP (#475).
26. Ultimate Disposal of Spilled Hazardous
Materials. A.W. Lindsey. Chemical
Engineering, Oct. 27, 1975. Soon to
be available from OSWMP.
27. Chemical Waste Land Disposal Facility
Demonstration Grant Application.
Minnesota Pollution Control Agency.
Environmental Protection Publication
SW-87d. Washington, U.S. EPA. Soon to
be available from NTIS.
PUBLICATION SOURCES
OSWMP publications can be obtained by
contacting:
Solid Waste Information Materials
Control Section
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
(please indicate three digit shelf no.)
NTIS publication can be obtained by
contacting:
National Technical Information Service
U.S. Department of Commerce
Springfield, Virginia 22161
(please indicate PB number)
31
-------
HAZARDOUS WASTE GUIDELINES: PLANS AND PROSPECTS
W.W. Kovalick, Jr.
U.S. Environmental Protection Agency
Office of Solid Waste Management Programs
Hazardous Waste Management Division
401 M Street, S.W.
Washington, D.C. 20460
ABSTRACT
Current Federal legislation authorizes EPA to issue both advisory guidances and
guidelines (which are mandatory for Federal facilities) related to solid waste management
systems. In addition, pending Congressional legislation contemplates a more regulatory
approach to hazardous waste management based upon a permit system operated primarily at
the State level.
This paper outlines the scope and tentative schedule for solid waste guidance/guide-
line issuances. It defines the nature of these issuances and contrasts them with the
EPA air and water regulatory approaches. In addition, the effect of pending legislation
is analyzed in the context of the current guideline/guidance plans.
It is a particular pleasure for me to
participate in this conference on land dis-
posal of hazardous waste in the "orienta-
tion" portion of the program. For as
essential as land deposition is to any
future waste management planning, it must
be viewed within the overall context of
complementary options and alternatives.
Thus, from the technical assistance pers-
pective of EPA, the opportunity to communi-
cate with the research community as to the
direction of our current guidance/guide-
line programs is very important.
Not only does it afford us an occasion
to assess the match between on-going re-
search efforts and current Agency guidance/
guideline plans, but also a chance for
dialogue as to what future gaps need to be
filled if effective guidances are to be
issued.
The cornerstone of current OSWMP
guidance/guidelines programs is the Solid
Waste Disposal Act, as amended (SWDA). The
critical sections of this Act relative to
hazardous waste bear some review as the
opportunities for formal guidance in it
are several.
Section 212 of the Act was the origin
of EPA's now familiar Report to Congress;
Disposal of Hazardous Wastes. Submitted to
Congress in June 1973, the Report was our
first major assessment of the seriousness
of the hazardous waste problem. Among its
major conclusions were that (1) hazardous
waste legislation was a key to solution of
the problem of mismanaged wastes and (2)
national disposal sites were not a viable
waste disposal strategy, given the avail-
able fledgling industry in this field. In
addition, the President submitted the
Hazardous Waste Management Act for consid-
eration by Congress in February 1973, be-
cause of the significance of this issue.
Section 204(a) of the SWDA Act carries
basic research, demonstration, and training
mandates. Much of the health and environ-
mental effects work, disposal operation
investigations, materials and energy recov-
ery work, and waste system studies now
underway are authorized under this section.
32
-------
Section 204(b) instructs EPA to collect
information and make it available through
publications and other means, to cooperate
with public and private groups, and to
make grants. This part of Section 204 is
significant to our guidance promulgation
efforts, and I shall return to it.
The mandate for guidelines for recov-
ery, collection, separation, and disposal
systems is contained in Section 209. Such
guidelines under Section 209(a) are recom-
mended to government agencies at all levels
- not just Federal ones. Section 209(b)
calls for model codes, ordinances, and
statutes as well as issuance of data on
costs of constructing, operating, and
maintaining technically feasible methods
for collection, separation, disposal,
recovery, and recycling.
Finally, Section 211 of the SWDA adds
some "teeth" to the otherwise advisory
guidelines under Section 209(a), in that
all Federal agencies shall ensure compli-
ance with such guidelines issued under that
section. You may be familiar with some of
the results of such guidelines. For exam-
ple, the Bureau of Land Management has
recognized the EPA Guidelines on Thermal
Processing and Land Disposal of Solid
Waste (Federal Register, May 14, 1974) as
well as the Recommended Procedures for
Disposal and Storage of Pesticides and
Pesticide Containers (Federal Register,
May 1, 1974) (also published by OSWMP) as
the minimum requirements for use of BLM
lands for waste disposal.
In summary, the current authorities of
interest here are Section 204(b)—the
issuance of recommendations—and Sections
209(a) and (b)—guideline issuances and
model ordinance drafting, respectively.
Before addressing our plans for haz-
ardous waste guideline development, some
definitions and clarifications are in
order. First, many of you are familiar
with the word "guideline" in the context
of Federal Water Pollution Control Act
(FWPCA) where "effluent limitation guide-
lines" (ELG) are to be set in accordance
with best practicable or best available
technologies. Thus, the ELG for an indus-
try sector is, in reality, an enforceable
permit requirement, not just technical
advice as is the case with solid waste
guidelines. The only persons for whom
solid waste guidelines are mandatory are
Federal agencies; for all others, they are
advisory. Thus, the word "guideline" has
a unique meaning in the solid waste legis-
lation.
A second issue of definition relates
to the focus in the FWPCA, as amended, and
the Clean Air Act, as amended, (CAA) on
performance standards. That is, the
standards or goals to be met by a potenti-
ally polluting activity should be specified
rather than the process or technology to
be used. We concur with this approach as
it leaves technological options open and
encourages development of new techniques.
Finally, one major contrast between
the FWPCA and CAA mandates and the approach
in solid waste bears review. Both the air
and water laws require industry-by-industry
standards relating to stationary emissions.
That is, specific levels of discharge to
the air and water environment are to be
set for each industry sub-segment. In
contrast to this legally required strategy,
those dealing with industrial wastes know
that they can be (and often are) shipped to
treatment/disposal facilities. In addition,
the solid waste statute refers to systems
and methods without reference to industry
segments. As a result, the current thrust
of our guidance/guideline development
efforts is on pathways that wastes follow
and the systems governing their flow.
What then are our plans to develop
guidances and guidelines? For ease of
discussion, we have defined the word
"guidance" as advice issued by EPA in the
Federal Register under the authority of
Sec. 204 of the Solid Waste Disposal Act.
Such guidance represents the Agency's best
technical counsel on an issue related to
hazardous waste management systems or path-
ways; it does not have regulatory status.
Guidelines are advice issued by the
Agency in the Federal Register under the
authority of Sec. 209. Although only
advisory to everyone else, Section 211
makes Sec. 209(a) issuances mandatory for
Federal facilities. Again, the guideline
represents our best technical advice, but
due to its impact on Federal facilities,
much more extensive impact analysis and
interagency review are necessary than
are needed for guidances.
33
-------
"System operations" guidances refer
generally to the flow of wastes from gen-
erator to storage, treatment, and ultimate
disposal. Potential subject areas are
many in number, but those in which the
States and others seem most interested at
present are waste transport control
(through trip-ticketing), wastes compati-
bility guides, facilities management sug-
gestions, site selection methodology, etc.
"Pathway" guidances would provide typical
performance specifications for incinerators,
chemical waste landfills, and chemical treat-
ment processes. As an example, an incin-
erator guidance would describe for the
person who has chosen incineration as his
disposal option, the optimum temperature,
dwell time, and turbulence characteristics
for the waste type he has selected. Obvi-
ously, our recommendation of such minimum
levels would be based on test burn experi-
ences with wastes of the same or similar
kind from which we had extrapolated.
Our strategy under current legislation
has two phases. First, issue system oper-
ation and pathway guidances under Section
204 as soon as practicable. This approach
allows us (1) to make Federal policy known
to a very broad audience (including indus-
try) , (2) to address our technical assist-
ance obligations to the States in a prior-
ity way, and (3) to signal industry and
the States as to our intentions, if
stronger Federal authorities should come
about.
A second part of our strategy is to
simultaneously explore the breadth and
extent of the hazardous waste management
problem among Federal agencies. To the
extent that specific problems are serious
enough and have not been addressed through
adherence to the guidances, Sec. 209 guide-
lines could then be issued.
Exhibit I is an interim plan for the
issuance of guidances and guidelines under
Solid Waste Disposal Act. It describes our
schedule for guidance/guideline issuance
over the next several fiscal years. Like
all good plans, it is subject to change.
It does, however, give a sense as to when
we expect the results of several technical
studies to be sufficient to issue advice.
Special comment regarding the column
marked Recommended Procedures is warranted.
Such a procedure will represent our best
technical counsel on a very specific pro
blem (such as disposal of wastes contami-
nated with a certain chemical) or advice
on a specific industry stream. The proce-
dures will be notable for their lack of
widespread applicability to many waste gen-
erators and disposers and/or their very
specific focus on single waste streams.
Such issuances are contemplated, for example
during FY 76 regarding PCB-contaminated
waste and during FY 78 regarding the trade-
offs of various treatment methods for some
streams in the organic chemical and petro-
leum refining industries.
Of special interest to this group
would be our plan to use the fruits of our
chemical waste landfill demonstration pro-
ject along with other results in FY 79 to
address waste-loading limits for landfill
sites and chemical waste landfill design.
With the long time frame on this in-
terim plan, the question of future Federal
legislative initiatives becomes very rele-
vant. As you may know, the Senate Committee
on Public Works has a bill numbered S.2150
which has been the subject of considerable
public dialogue for over a year. On
December 15, 1975, the House Subcommittee
on Transportation and Commerce issued a
staff print of a Solid Waste Utilization
Act for public comment. Thus, both Houses
of Congress appear to be ready to address
the issues of waste management, including
hazardous wastes, in specific terms.
The concepts included in both of these
legislative initiatives with regard to haz-
ardous waste are very similar. First, there
are special sections of these comprehensive
drafts devoted to hazardous wastes. Second,
the Administrator must define or identify
hazardous wastes within certain time frames
in the drafts in both Houses. Third, a
program for the permitting of the storage,
treatment, and disposal is mandated in both
drafts; the House version also recognizes
generator reporting obligations and the
importance of the transportation link to
effective management. Both drafts recognize
operational, technical, institutional, and
economic requirements for permit holders
through permit conditions.
Additionally, both drafts suggest State
implementation of such a permitting effort
via approved Federal programs, and outline
monetary disincentives in terms of withdrawn
-------
Federal grant funds if the States do not
assume the program. In the case of the
House draft, only funds supporting the
implementation of a hazardous waste program
would be withdrawn instead of all State
implementation money as in S.2150.
Even with this generalized overview,
I think you can see the match between our
current activities and prospective legis-
lative initiatives. Almost all of the
guidances that we have suggested could be
translated into decision tools and/or spe-
cifications for Federal of State permit
writers.
For that reason, we feel there is much
to be gained from the early dialogue that
will take place concerning guidance issu-
ances. Not only the research community,
but also industry, labor, public interest
groups, and the academic community inter-
ested in effective hazardous waste manage-
ment will be better able to focus their
effort if Federal policy is clear and an
open subject for continuing discussion in
the months ahead.
Thank you very much.
35
-------
Prospective
Hazardous Waste Management Federal Register Issuances
Guidance
(Sec. 204)
Recommended
Procedure
(Sec. 204)
Guideline
(Sec. 209
FY 76 Policy Statement
on HW Mgt.
Site Selection Criteria
Disposal of PCB-containing Wastes
Disposal of VC-containing Aerosol Cans
u>
ON
FY 77 Waste Transportation
Mgt. (Manifest Systems)
Compatability of HW at Disposal
Facilities
Policy on Use of Public Lands
for HW Facilities
Mgt. Aspects of HW Facilities
(Insurance, Bonding)
Model State HW
Statute (Sec. 209 b)
FY 78
Std. Sampling (and Analysis) for HW
State HW Mgt. Program - Resources
and Organization
-------
Exhibit I (Continued)
FY 79 (cont'd)
Definition of HW (including
Standard Leaching Test)
Reference Method for
Evaluating Chemically
Fixed Wastes
Incineration Processes
for HW
PCBTM* for Organic
Chemical and Petroleum
Industries
FY 79 Determination of Loading
Limit of Waste Sites
PCBTM* for Inorganic
Chemicals and Metals
Mining and Refining
Industries
Chemical Waste Landfill
Design
PCBTM = Physical, Chemical, Biological Treatment Methods
-------
DOCUMENTATION ON ENVIRONMENTAL EFFECTS OF POLLUTANTS
A. S. Susten and R. S. Raskin
U.S. Environmental Protection Agency
26 West St. Clair Street
Cincinnati, Ohio 45268
ABSTRACT
To support their expected regulatory posture regarding the management and land dis-
posal of hazardous wastes, the Office of Solid Waste Management Programs (OSWMP) is
actively assembling an extensive scientific data base which must be considered if promul-
gated guidelines are to be scientifically sound and economically feasible. As part of
that effort OSWMP has requested the Office of Research and Development (ORD) to develop
from the existing literature a series of documents on the human health and ecological as-
pects associated with a number of selected pollutants—largely trace elements and pesti-
cides. The reports are structured to be multimedia in scope, i.e., covering air, water,
and land environments, and to assess the impact on life forms interacting with those envi-
ronments. While each document is intended to be an authoritative compilation within the
scope requested by OSWMP, no attempt has been made to establish or recommend environmental
criteria levels. The format, component parts, and types of information being assessed
will be described.
INTRODUCTION
The Solid and Hazardous Waste Research
Division (SHWRD), as part of a program to
identify and characterize hazardous wastes,
is developing a series of comprehensive re-
ports on specific aspects of a number of
selected substances—largely trace metals
and several organic entities. The sub-
stances chosen for inclusion in the "REEP"
(Reviews of the Environmental Effects of
Pollutants) program have been deemed haz-
ardous and identified as components of
waste streams destined for land disposal.
The planned subjects for the REEP reports
are: arsenic, asbestos, benzidine, beryl-
lium, cadmium, chromium, copper, cyanides,
DDT, endrin, fluorides, lead, mercury,
methylparathion, PCB's, selenium, toxa-
phene, and zinc.
This paper is a brief overview of
three aspects of the REEP program. The
items to be discussed include:
1. Purpose and Use
2. Format and Scope
3. Some General Findings
PURPOSE AND USE
The REEP program was initiated in re-
sponse to a need expressed by the Office of
Solid Waste Management Programs (OSWMP) for
comprehensive multimedia, multireceptor re-
ports on selected pollutants. The REEP
program, presently being developed under
the authority of Sections 204 and 212 of
the Solid Waste Disposal Act, as amended
1970, is to provide information support for
OSWMP's anticipated regulatory posture re-
garding the proper management of hazardous
waste materials, including handling and
disposal. The documents developed under
this program do not and are not intended to
establish disposal criteria or recommended
levels of pollutants in any media. They
will, however, provide the user with part
of a growing data base which must be con-
sidered if promulgated guidelines/standards
for the storage, treatment, and land dis-
posal of hazardous residuals are to be
38
-------
scientifically sound and economically
feasible.
The reports present information on
factors which influence the potential es-
cape of pollutants from land disposal
sites and review potential impacts of the
subject pollutants on all media and life
forms. More specifically, OSWMP expects
the reports to:
1. provide an up-to-date compendium
of information on toxicities (ef-
fects associated with exposures
to specific substances contained
in the air, water, and land
media);
2. provide insight into the effec-
tive soil and plant indicators
for detecting the presence of
substances;
3. provide general data on the com-
plexity, cost, and reliability of
state-of-the-art analytical pro-
cedures for determining the pres-
ence of substances;
4. provide information on predict-
able reaction products of sub-
stances to aid in the design of
criteria relating to mixing of
wastes; and
5. permit assessment of the need for
additional air emission standards
due to the operational charac-
teristics of hazardous waste
treatment sites (1).
In addition to their designated user,
the OSWMP, the reports developed under
this program should be of value to other
program offices within the Agency as both
an information source and an identifier
of knowledge gaps.
FORMAT AND SCOPE
As stated above, these reports are
primarily concerned with the effects and
transport of selected pollutants in the
environment. Within the desired scope,
each document is structured to be compre-
hensive although not necessarily encyclo-
pedic. To facilitate the coverage of each
topic a "modular" format was chosen. This
format readily lends itself to constant
literature review and updating, almost in
a "loose leaf" fashion; and is directed at
the individual with specific scientific
interests and expertise. Topics which are
covered and the general format of a REEP
document are shown in Table 1. In general,
representative studies are selected to be
included in a REEP document. It should be
noted that REEPs do not cover or discuss
in detail anthropogenic sources, control
technologies, or economic aspects of the
subject pollutants. Much of this work is
being conducted by other groups and pro-
grams within the Agency.
The REEP format allows information to
be conveyed to two different audiences at
two different levels. In fact, a REEP re-
port could be considered to be two docu-
ments—an Executive Summary and a Detailed
Report.
The first, a brief overview or
"Executive Summary" (comprised of Chapter
1.0 of the REEP), is addressed primarily
to the relatively nontechnical individual
interested in a broad understanding of the
subject. The second document (embracing
Chapters 2-8) is aimed at individuals
working in the area who are concerned with
details and experimental approaches. The
detailed chapters and sections of the re-
ports are to provide the scientific basis
for the Summary Chapter and constitute the
referenced body of knowledge upon which
OSWMP/EPA intends to establish its case
for action in regard to the exercise or
nonexercise of regulatory controls, and
its defense of such actions in administra-
tive or judicial proceedings. A descrip-
tion of the types of information con-
sidered in each chapter and the manner in
which it is to be presented are given be-
low.
Chapter 1.0--Summary
This chapter should present in clear
and concise language the important find-
ings, concepts, and relationships estab-
lished in the scientific chapters and sec-
tions of the document. An individual read-
ing Chapter 1.0 should gain a brief over-
view of information relevant to the poten-
tial for transport, movement, reactions in
the environment, and health and ecological
effects which might occur. Conclusions
regarding the likelihood of environmental
hazard and existing information gaps are
presented as a conspicuous subdivision of
Chapter 1.0. (See Table 1.)
39
-------
The conclusions are numbered and
usually consist of one to two sentences.
No conclusions can be presented unless
they are justified in the Summary of Find-
ings subdivision of the Summary. (See
Table 1.) Any information presented in
the Summary of Findings subdivision should
reference by section numbers the appropri-
ate detailed chapter(s)/section(s) of the
report from which it was drawn.
Chapter 2.0--Chemical and Physical Proper-
ties and Methods of Analysis
In this chapter, the characteristics
of the pollutant are to be discussed from
a viewpoint which establishes a relation-
ship between properties and environmental
significance of the pollutant. Esoteric
chemical or physical properties, which can
only be observed under extreme laboratory
conditions and are environmentally un-
realistic, are not germane to the discus-
sion. On the other hand, information on
chemical formulas and structures, physical
states in the environment, stability and
persistence, volatility, reactivity, solu-
bility, and other properties of potential
environmental importance is of interest.
The discussion in Chapter 2.0 should be in
relation to the pollutant's potential for
transport and transformation in all media
and impact on life forms. Reaction
rates, thermodynamics, and other quanti-
tative estimates of probability of move-
ment, etc., are pertinent if they are en-
vironmentally feasible. Where specific
examples do exist, the full ramifications
and details should be presented in the
proper chapter(s)/section(s) which follow.
To effectively support the narrative dis-
cussion, tables containing formulas and
properties of the pollutant are included.
Also included as part of this chapter
are discussions relative to available
techniques for measurement and analysis of
the various environmentally significant
forms of the subject pollutant. Specif-
ically, some of the topics covered include
relevant methods and their applications to
air, water, sludge, and biological tis-
sues, the sensitivity and reproducibility
of the technique on routine use (upper and
lower levels in sample being tested),
problems encountered in sample prepara-
tion, selectivity of the method, and a
general indication of the economy of the
method.
Tables containing the above informa-
tion help to summarize the data for the
reader.
Chapters 3.0 through 6.0--Biological
Aspects
The interactions of pollutants with a
wide variety of life forms are covered in
these chapters. A suggested approach to
covering the biological information is
shown in Table 1. The writers, however,
do have some latitude in determining where
to cover information on certain life
forms. For example, some authors feel
more comfortable including phytoplankton
with the plants (Chapter 4.0) rather than
with microorganisms (Chapter 3.0) as shown
in Table 1. Regardless of how the life
kingdoms are classified, the discussion of
each chapter is approached in a similar
manner and, assuming the data are avail-
able, is divided into sections called
Metabolism and Effects. Metabolism (Meta-
bolic Processes) in these reports, is used
to describe the factors which ultimately
determine the body burden and form of the
pollutant in the organism. This section
is discussed from the standpoint of uptake
and absorption, transport and distribu-
tion, biotransformation and elimination.
The Effects portion of each chapter
or section presents data derived from both
acute and chronic studies. The aim is to
present information which would help es-
tablish clearly-defined cause-effect and
dose-response relationships. General and
detailed information pertaining to general
toxicity, teratogenicity, mutagenicity,
lethality, carcinogenicity, and growth and
development, is of interest and should be
included in the Effects section(s) under
the proper heading. Data should be taken
from epidemiological, clinical, and ex-
perimental laboratory studies.
Where possible, the influence of
other substances and life forms, disease
states, drugs, habits (such as smoking or
alcohol consumption), etc., on Metabolism
and Effects should be considered. In the
real world, the above conditions often
exist and may be of importance. For exam-
ple, it has been shown that calcium and
iron deficiencies, diets, and hereditary
enzyme deficiencies in children can affect
lead absorption and toxicity (2-5). These
factors must be considered if the health
and ecological hazards of a pollutant are
-------
to be "accurately" assessed.
SOME GENERAL FINDINGS
Sections 7.0 and 8.0--Environmental
Sections
Localized in these two chapters which
in some cases have been combined into one,
is information relevant to mechanisms of
environmental transport,transformation and
interactions, movements through food
chains .and model ecosystems. Pollutant
levels in various media, for what are
thought to be situations representing both
normal and abnormal levels, are also sum-
marized here. As part of the above dis-
cussions, items of interest include media
distribution processes and rates, and data
on persistence and degradation in each of
the media. The goal of these two chapters
is to provide a link between the chemical
and biological chapters 2-6, and the en-
vironmental chapters 7-8. Since the
physical and chemical properties and bio-
logical aspects have been covered in de-
tail in prior sections, the discussions on
mechanisms and rates can be general but
always supported by detail located in
other sections. Figures which illustrate
the flow of the hazardous pollutant
through the environment, subsequent envi-
ronmental and biological interactions,
incorporation in food webs, and environ-
mental sinks are included to support the
discussion.
Before leaving the discussion of
format and scope, it is important to point
out a particular facet of this "modular"
format which must be considered if the
document is to be efficient and concise
but still complete. In many cases infor-
mation is relevant to more than one chap-
ter or section. The potential for vast
duplications and repetitions of the same
information looms as a potential disad-
vantage. Recognizing this problem, con-
tractors are encouraged to maintain
close coordination among their writers so
that each is aware of what information
will be necessary in each section and what
level of detail is required. Decisions
can then be made as to the primary loca-
tion of the information. It therefore be-
comes very important to have closely
coordinated chapter to chapter and section
to section referencing to direct the
reader to pertinent information covered in
greater or lesser detail in other parts of
the document.
Since this program is primarily con-
cerned with the review of existing litera-
ture and is not a basic research program,
outstanding or newsworthy findings were
not anticipated. In that light, some of
the general findings of the program to
date will be presented.
Acute Data
Generally, a plethora of information
relative to acute and subacute exposures
of experimental animals, wild and domesti-
cated animals, and humans is available.
Much of what we know about metabolic proc-
esses and potential toxicities of these
pollutants is indeed derived from acute
data. Besides providing a means for
studying mechanisms of toxicity, acute
data may provide insight regarding the
degree of hazard that might be associated
with exposure to relatively high concen-
trations of the substance as well as an
indication of those physiological systems
or organs which may be affected.
Chronic Data
Although some chronic data on animals
and humans are available, there are those
that feel that "good" data on chronic ex-
posures and "low levels" (similar to en-
vironmental levels) are lacking. This is
especially true as it relates to assessing
the carcinogenic potential of pollutants.
As pointed out in a report to Congress,
"even in the case of recognized carcino-
gens the actual risk posed by ingesting
very low concentrations is not known at
this time." (6)
Unfortunately, data are also incom-
plete regarding subtle changes in physi-
ology, if any, that may occur as a result
of exposure to environmental levels of
pollutants. For example, in spite of a
great deal of study, the debate over the
role of cadmium as a potential etiological
factor in hypertension still continues un-
resolved. The data at present are gen-
erally insufficient quantitatively and at
times qualitatively to exactly predict the
degree of hazard posed by levels of pol-
lutants presently in or projected to be in
our environment.
The picture is even cloudier since
humans, animals, plants, etc., are often
41
-------
exposed to a combination of pollutants.
We know little at this time about the ef-
fects (additive, protective, etc.) which
may result from long-term simultaneous
exposure to low levels of pollutants. Do
different combinations and levels of pol-
lutants in drinking water and air result
in synergistic or antagonistic effects?
This in only one of many questions which
are unanswerable at this point in time
and perhaps even in the future.
Placenta! Transfer
Most of the pollutants studied to
date are capable of crossing the placenta.
However, except in a few cases of exposure
to relatively high concentrations of mer-
cury (7-8) and PCB's (9), gross fetal ef-
fects have generally not been confirmed
to be of environmental origin. Animal ex-
periments have verified that pollutants
will cross the placenta and in sufficient-
ly high doses result in demonstrable
teratological effects. Of more recent
concern, however, are the possible occur-
rences of subtle fetal effects which may
not be immediately apparent at birth but
become manifest much later in postnatal
development. For example, a recent retro-
spective study examining the effects of
high concentrations of lead in drinking
water (average about 400 micrograms/liter)
suggests a strong correlation between lead
levels in the drinking water and the de-
velopment of mental retardation in chil-
dren ages 2-6. The children studied were
exposed to lead during gestation and early
infancy. (10) Thus we can no longer be
confident, if indeed we were, that failure
to observe gross anatomical changes in
newborns is proof of nonhazard.
Reactions in Waste Streams
The interactions and reactions of the
hazardous materials are also of interest,
particularly to those concerned with waste
handling and disposal. The REEP documents
provide basic information on physical and
chemical properties which can be used to
attempt to predict potential reactions,
etc. However, the actual data on migra-
tion and chemical reactions of materials
in complex waste streams are just being
developed, some of which will be presented
in part at this symposium. Unfortunately,
most of the data will not be available
soon enough to be incorporated into the
REEP program.
Environmental Alterations of Pollutants
Finally, the form (speciation) of the
pollutant in the environment, which is or
can be an important determinant of its
movement and potential toxicity, is at
times not very clear. This is still the
case with mercury. Although much research
has been conducted and a good body of evi-
dence indicates that inorganic mercury can
be converted in water environments to the
more toxic organic mercury, there are
those who suggest that this transformation
cannot occur sufficiently fast or quanti-
tatively to be of environmental concern.
(11) Similarly, recent evidence suggests
that inorganic lead can be converted by
microorganisms in lake sediments into
volatile tetralkyl lead compounds. (12)
To what extent this occurs in the environ-
ment, if at all, still needs to be de-
fined.
In summary, documents such as the
REEPs can be and remain (with constant
updating) valuable sources of information
to EPA and others.
42
-------
TABLE 1. TOPICAL OUTLINE OF ENVIRONMENTAL EFFECTS REPORTS
1.0 Summary
1.1 Summary of Findings
1.2 Conclusions
2.0 Chemical and Physical Properties and Analysis
3.0 Biological Aspects in Microorganisms (generally uni-
cellular forms but may include plankton)
3.1 Bacteria
3.2 Protozoa
4.0 Biological Aspects in Plants
4.1 Non-Vascular (algae, fungi, mosses)
4.2 Vascular
5.0 Biological Aspects in Wild and Domestic Animals
5.1 Fish and Aquatic Organisms
5.2 Birds and Terrestrial Wildlife
5.3 Domestic Animals
5.4 Etc.
6.0 Biological Aspects in Humans
7.0 Media Distribution and Processes
8.0 Environmental Interactions and Their Consequences
43
-------
REFERENCES
1. Lehman, J., 1975, Memorandum to
Thomas Bath, May 9. SHWRL Criteria
Documents, Washington,D.C.,U.S.E.P.A.
2. Karhausen, L., 1973. "Industrial Lead 11.
Absorption," in: Proc., Int. Symp.,
Environmental Health Aspects of Lead,
Amsterdam. October 2-6, 1972. D.
Barth, A. Berlin, R. Engel, P. Recht,
and J. Sweets (eds.), p. 427-440.
3. Goyer, R. A., and B. C. Ryne, 1973.
"Pathological Effects of Lead," Int. 12.
Rev. Exp. Pathol... 12:1-77.
4. Six, K. M., and R. A. Goyer, 1970.
"Experimental Enhancement of Lead
Toxicity by Low Dietary Calcium,"
J. Lab. Clin. Med.. 76(6):933-942.
5. Six, K. M., and R. A. Goyer, 1972.
"The Influence of Iron Defiency on
Tissue Content and Toxicity of In-
gested Lead in the Rat," J. Lab. Clin.
Med.. 79(1):128-136.
6. Preliminary Assessment of Suspected
Carcinogens in Drinking Water. June
1975, Intel 1-Report to Congress
(cited in Toxic Material News, Janu-
ary 1, 1976, page 5).
7. Matsumoto, H. G. Koya and T.
Takeguchi, 1965. "Fetal Minamata Dis-
ease: A Neuropathological Study of
Two Cases of Intrauterine Intoxication
by a Methyl Mercury Compound," J_._
Neuropath Exp. Neurol., 2£: 563-574.
8. Curley, A., V. A. Sedlak, B. F.
Girling, R. E. Hawk, W. F. Barthel,
W. H. Likosky, and P. E. Pierce, 1971.
"Organic Mercury Identified as the
Cause of Poisoning in Humans and
Hogs," Science, 172-65-67.
9. Funatsu, H., F. Yamashita, Y. Ito, S.
Tsugawa, T. Funatsu, T. Yoshikane, and
M. Hayashil, 1972. "Polychlorbiphenyl
(PCB) Induced Fetopathy. I. Clinical
Observation." The Kurume Medical
Journal, 19 (1):43-51.
10. Beattie, A. D., M. R. Moore, A. Gold-
berg, M. J. W. Finlayson, J. F.
Graham, E. M. Mackie, J. C. Main, D.
A. Mcharen, R. M. Murdoch, and G. T.
Stewart, 1975. "Role of Chronic Low-
Level Lead Exposure in the Aetiology
of Mental Retardation," Lancet, 1
(7907): 589-592.
Stopford, W. and L. J. Goldwater,
1975. Mercury in the Environment: A
Review of Current Understanding,
Abstract. Third Annual Conference,
"Heavy Metals in the Environment,"
sponsored by NIEHS/EMG. Chapel Hill,
North Carolina, May 15-16.
Wong, P. T. S., Y. K. Chan, and P.
Luxon, 1975. "Methylation of Lead in
the Environment," Nature 254: 263-
264.
44
-------
HAZARDOUS WASTE SAMPLING
R.D. Stephens
California Department of Health
2151 Berkeley Way
Berkeley, California 94704
ABSTRACT
Procedures and equipment for the sampling of liquid and sludge hazardous wastes will
be discussed. The techniques are primarily applicable to bulk (vacuum trucks) and bar-
reled wastes. Materials of a wide range of viscosity, corrosivity, volitivity, and solids
content have been sucessfully handled. The techniques are designed to give representative
samples of actual complex multiphase wastes. Equipment design is simple and inexpensive
and allows for rapid sampling necessary for obtaining total input data on large hazardous
waste sites. Sampling handling and preservation will be discussed in light of the wide
variety of wastes handled. Appropriate sampling techniques do not necessarily produce
samples statistically representative of the total waste stream. In our experience, the
presence of sampling personnel significantly perturbs the flow of waste into a disposal
site. Approaches to deal with this problem will be discussed. Our experiences in a
large-scale sampling program in the Los Angeles area at six hazardous waste sites will be
related as well as the approaches to classification and analysis of the resultant hazard-
ous waste potpourri.
INTRODUCTION
The State of California, Department of
Health has been involved in several aspects
of sampling of hazardous wastes. These
activities have necessitated the develop-
ment of sampling equipment and procedures,
as well as sample preservation and analyt-
ical procedures. In this development many
problems of waste complexity, intracta-
bility and hazard have been encountered.
We have determined, however, that success-
ful sampling and analysis of hazardous
wastes is vital to a management system.
TEXT
The California Department of Health
is charged with the responsibility for
setting up a statewide management program
for hazardous waste. In this program we
are concerned with many aspects of hazard-
ous waste generation, transport, recovery,
and disposal in terms of the environmental
and public health impacts. One of the
primary tasks which faced us in our program
was to obtain information on the identity
of hazardous wastes generated and disposed
of in the State. Much information was
available to us from a variety of industry
studies, many of which were sponsored by
the U.S. Environmental Protection Agency.
Although these studies have been invaluable
to our program, they were not fully ade-
quate for our needs for two reasons.
First, much of the information on the waste
identity contained in these studies is
based on estimates of both waste volumes
and composition and not analytical data on
actual wastes. Extrapolation of such esti-
mated data to different areas of the coun-
ty and to different industries was felt to
be unsatisfactory. Second, except in a
few cases, the information is not in suffi-
cient detail to be of great assistance for
disposal site or regional waste management.
It therefore became apparent that a
certain amount of analytical data would
have to be generated from samples taken
45
-------
from real hazardous wastes. This sampling
and analysis program would be designed to
complement a new State hazardous waste
manifest system in which producers of
hazardous waste are required to reveal the
chemical identity and concentration of all
hazardous waste components prior to ship-
ment from production facility. A fac-
similie of this new manifest is shown in
Figure 1.
A second and equally important aspect
of the California Hazardous Waste Program
is the surveillance and enforcement of
State regulations on what wastes are to be
handled and how they are to be treated.
Assessment of waste hazards, environmental
impacts and compatibilities must be pri-
marily based on a sound knowledge of waste
chemical composition. Such knowledge
requires a simple, rapid.and representative
RavlMd Deeambtr 1974
CALIFORNIA LIQUID WASTE HAULER RECORD
STATE WATER RESOURCES CONTROL BOARD
009-Q00928
PRODUCER Of WASTE (Must be filled by producer)
1 1 1
Pick up Address:
(NUM..*) |.r-..T) (c.-rv)
Type of Process 1 I 1 I 1
wastewater treatment, pickling bath, petroleum refining)
DESCRIPTION OF WASTE (Mutt be filled by producer) ]
Check type of wattes:
D Other (Spec.fy) III
Component* COD« NO.
orgamcs (list), cyanide)
n n
r r
4. [
5. |
r r
Bulk Volume: Q gal D ton* D 42 gel.) Dottier (
(HUM. en) I«I.BC,FV»
Physical State: D solid Q liquid D sludge D other
Special Handling Initructlons (If any)
The watte is described to the bett of my ability and it was delivered to a licensed liquid waste hauler (If
applicable),
1 certify (or declare) under penalty a1 perjury.
HAULER OF WASTE (Must be filled by heulerl
I I I I
Dam
Pick Up. Time. nom
Jnh Nn .: No. of Loarl* nr Trios. Unit No.
(••-•CIFT)
facility named below and was accepted
that the foraoolna Is true end correct.
DISPOSER OF WASTE (Must be filled by disposer) [
1 1 1 1
CODE NO
The hauler above delivered the described weate to this disposal facility and it waa an acceptable
loo.l mnrlctlom.
Handling Method(s):
D recovery r— r— i
PI trB-tmant<«,eClfV): 1 1 1
Q disposal (specify): D pond D spreading Q landfill D injection well _____
nlnnniuil Date.
( f
FOR INFORMATION RELATED TO SPILLS OR OTHER EMERGENCIES INVOLVING
Figure 1. Hazardous waste manifest.
The identification in such detail of haz-
ardous components is something which
requires considerable effort on the part
of the waste producer. In our experience
such efforts are not taken unless there is
some attempt at verification. This veri-
fication has taken the form of sample
collection and analysis.
sampling method along with good analytical
techniques which provide the proper data.
Some of the parameters are listed
below which must be considered in hazard-
ous waste sampling programs.
46
-------
Phase Complexity
Hazardous wastes appear as all phases:
solid, aqueous, and organic liquid. Very
often the waste is a complex mixture of
all of these phases. Sampling techniques
must be able to give representative frac-
tions of all phases.
Access to Waste
in
Hazardous wastes are contained
ponds, vacuum trucks, barrels, etc.
Sampling must be adaptable to all of these.
Chemical Reactivity
Many wastes are highly corrosive or
strong oxidizers. Many wastes, although
not particularly reactive, are, because
of their physical nature, very hard on
equipment. These features place severe
demands on equipment design.
The relative undefined nature of most
waste, creates a significant safety prob-
lem to sampling personnel. Rather exten-
sive precautions must be taken.
Sample Containment and Preservation
The containment and preservation of
corrosive, highly toxic, or highly volatile
samples in the field, present significant
problems.
The California Department of Health
has been involved in two specific programs
of hazardous waste sampling during this
last six months. In cooperation with the
University of Southern California, Envi-
ronmental Engineering Department, under
the direction of Dr. Kenny Chen, we have
been involved in a "Case Study" of a
major hazardous waste disposal site in
southern California.
The location chosen for the study was
the B.K.K. disposal site, located in the
southern portion of the city of West
Covina, in the San Jose Hills area. This
site is classified by the State Water
Resources Control Board as a "Class I"
landfill. Under this classification, the
site, or certain portions of it, possesses
no continuity with ground waters or
surface waters. With this classification,
the site is virtually unlimited as to the
type of waste which can be accepted. The
primary exception is radioactive waste.
The B.K.K. Company is one of the largest
industrial waste disposal companies in the
Western United States. It averages about
5x10 gal./month of liquid waste.
Approximately 60% of this volume is clas-
sified by the Department of Health as
"hazardous". This volume represents
approximately 30% of the liquid industrial
waste "legitimately" disposed in the Los
Angeles area and approximately 45% of the
hazardous wastes. At the B.K.K. disposal
site, extensive "total input" sampling was
conducted over a period of two weeks.
During this period several hundred samples
were obtained which represented essentially
all of the waste types taken at the site.
Samples were taken with the sampler shown
in Figure 2.
COMPOSITE LIQUID WASTE SAMPLER
(CoLiWaSa)
Volume = .4U (.43 qt.)/ft. of depth
-3/8" PVC rod
,1 7/8" - outer dimensions
1 5/8" - inner dimensions
-Class 200 PVC pipe
•No. yh neoprene stopper
3/8" S.S. nut and washer
Figure 2. Composite Liquid Waste Sampler
This device is relatively simple, consist-
ing of a hollow PVC tube, nominally 11/2
inches I.D., with a concentric PVC rod
which is attached to a neoprene stopper.
The sampler is lowered into a liquid or
sludge waste to cut across a column of
47
-------
material. The sampler is then closed at
the bottom, trapping a sample inside
which is representative of all the layers
and phases of the waste. Volume of sample
taken is about 350 ml/foot of depth of sam-
ple. Characteristics considered important
in this sampling device are: It can be
used on ponded, bulk, or containerized
waste; sampling is rapid and simple;
equipment can be readily cleaned; equip-
ment is inexpenisve.
These characteristics are particular-
ly important for a total input type sam-
pling program at major disposal sites
because of the large numbers of waste
loads which must be sampled. Waste samples
can be transferred directly from the
sample tube to a sample container. The
currently used polyethylene sample bottles
are sealed immediately and stored in the
field vehicle until the end of the day.
At this time they are transported to cold
storage (4 C), where they are kept until
analysis begins. We attempt to start
analysis within one week subsequent to
sampling. We currently have no data re-
lating to either the stability or insta-
bility of these samples after sampling.
Proper and safe sampling procedures have
been greatly aided by the new haulers
manifest shown in Figure 1. This document
usually gives a good indication as to the
potential problems and safety hazards
which may be encountered. Current usage
of the waste hauler manifest gives fairly
good information on general waste cate-
gories. Some of these categories are
acids, alkalis, cyanides, pesticides,
plating solutions, etc. Although this
information is inadequate for the develop-
ment of a chemical inventory of wastes, it
is very helpful in the determinations of
proper sampling procedures and in initial
analytical techniques.
When the goal of a sampling program
is to develop a chemical inventory of
waste traffic at a disposal site, one must
consider the effect of the sampling pro-
gram on the flow of wastes. It has been
our experience that the presence of sam-
pling personnel at a disposal site signif-
icantly affects waste volumes. Informa-
tion as to where sampling is being conduct-
ed rapidly spreads among haulers and dis-
posal sites. This factor can lead to a
totally unrepresentative sample of waste
input. Our solution to this problem is
to simultaneously sample all or most of
the sites within a region. This elimi-
nates the alternative, non-sampled, dis-
posal site to the apprehensive waste
hauler or site operator. This approach
can however, be only partially successful
because waste can be sorted, dumped at off
hours, or illegally dumped. Some estima-
tion of the perturbation caused by sam-
pling can be estimated by an inspection
of detailed records over a several month
period. This is now possible in our
department because of the waste hauler
manifest and the automated data system
which it supplies. Inspections are made
of waste traffic into the sites in the
region of a sampling program several weeks
before and after the actual sampling. In
this way any unusual fluctuations can be
noted. This effect on waste volumes
appears not to be a significant problem
on spot checking or surveillance activi-
ties. In this type of operation, sampling
personnel come and go on an irregular
schedule, which precludes adaptation by
the haulers and disposal sites.
Record keeping is of importance in
any sampling program. In hazardous waste
sampling, this becomes an important con-
sideration when ten vacuum trucks are
lined up at a disposal site, waiting to
unload. To facilitate the process, the
form shown in Figure 3. was used. This
form is both sample record form and an
analytical approach which is described on
the reverse side.
Analysis of these waste samples pose
some rather unique problems. The variety
and complexity of them is sometimes over-
whelming. In light of this, a workable
scheme for the analysis had to be devel-
oped. Our approach has been to develop
four levels or hierarchies of analytical
complexity. At level I, only phase compo-
sition data is acquired, i.e. solid,
aqueous, and organic liquid phases. Pro-
gressing through levels II, III, and IV,
more and more detailed information is
acquired about the waste composition.
Level IV, is specific compound or ion
analysis. The analytical flow scheme is
shown on Figure 4. Decision on what
initial analysis to do is usually based
upon waste origin and composition infor-
mation taken off the waste haulers mani-
fest. More detailed analysis is usually
48
-------
Chemical Components
HAZARDOUS WASTE UNIT
SURVEILLANCE FORM
Lab No.
Sampling Date
Manifest No.
Time
Producer
Producer's Address
Hauler
Hauler's Address
Process Type
Waste Type
Concentration
Volume
(Units)
Brief Physical Description
HWU - 7/75
Requested Analysis
I. _ Physical Data (% wt) : Organic phase
II. _ General Chemical Data
_ A. Flash Point (°C) _
Aqueous phase Solid phase
B. Volatile Organics (% wt)
C. Percent Weight: Aromatics _
Saturates
Oxygenates
Other
95°
> 95°
D. Water Soluble Organics (% wt)
E. Residue on Evap. (mg/kg)
F. Sulfide Precipitate pH 3
pH 7
pH 9
(ppn)
(ppm)
(ppm)
G. Solution pH
H. Organometallics
I. Water Soluble Organics
J. Solid Phase: % organic
Total acidity/alkalinity
mg/1
mg/1
% inorganic
III. A. Organic Junctional Group Determination
B. Organic Quantitative Analysis:
Test Requested
1.
2.
3.
4.
Results
IV. A. Organic Characterization
1.
2.
3.
V.
Metals Analysis
Analysis Request
1.
2.
3
4.
5.
6.
Results
Figure 3a. California Liquid Waste Surveillance form.
Figure 3b. Hazardous Waste Analysis Form (reverse side
of surveillance form).
-------
E SAMPLE!
1 Aqueous Insoluble Organic Phase K — r-
IA LB
Flaah Point 1 1 95° Distillate
II
IB
Solubility Group Tests 1
III
I" , i-
Aromatics, Unsat. Soaps
) E F
, Org. 1 Residue III pH
ids on Evao. total H
1 Acid, Neut
A _
1 Oru. N, Ore. Cl , Ore. P. etc.
A
a —
G
+ OH-
. , Base, H?S
, Jt
Total e
Residue
ppt . If-'-
I
xtracted
(tol. )
-^ Solid Phase | L
Soluble
Volati
I LJ JT>
s Ignition ^Inorganic
e Oreanics Determination ^Organic
1 (Ashina)
I Specific Compound Analysis I
I Specific Anion, Cation Analysis
EXPLANATION OF STEPS
I Sample separation: Sample ie separated into respective phases. In case of emulsions or sludges, use appropriate separation techniques - Record % weight
and % volume of Aqueous, Organic, and Solid phases (Dry weight).
Flash point determination on organic liquid. o
Volatile organic determination done on all samples with organic phase: 10% by volume, record weight % <95° B.P. and>95 B.P.
C Separation using appropriate technique to separate class of organic cpds. i.e. aromatics, saturates, alcohols etc. Record % weight of each class.
D Acidify aqueous phase and extract with freon. Evaporate solvent and record % weight extractable, non volatile organics.
E Evaporate aqueous layer to dryness and record residue or evaporation. Subtract organic extractables from total residue.
F Precipitate metals as sulfide in acid, neutral, and base solution.
G Record pH titrate for total alkalinity/acidity.
Toluene extract of Aqueous layer. Evaporate toluene, ash residue, record residue for organometalics.
I Steam strip and record weight of volatile, water soluble organics.
J Ignite solid - determine general organic, inorganic nature.
If solid is mixture, dry at 105°, then ignite, record 7= organic and inorganic.
Do standard solubility tests for organic functional groups (qualitative) - Record all positive and negative tests.
Organic nitrogen, sulfur, chlorine, phosphorus, quantitative tests as requested. Do standard qualitative scheme for anion and cation groups.
TV A Specific identification of organic molecules with appropriate technique. Record identity and % weight of each cpd. found.
B Specific quantitative cation, anion analysis (quant.) by appropriate technique as requested.
Figure 4. Flow scheme for waste analysis.
done on the basis of indications from the
preliminary data. Using this approach we
are able to develop general analytical data
on all samples taken and to concentrate
efforts on selected samples for detailed
analysis. The analytical program is cur-
rently nearing completion of the work on
samples taken in the "total input" study.
I am, however, not as yet prepared to dis-
cuss these results in detail. A report
will issue jointly from the Environmental
Engineering Department at U.S.C., and the
California Department of Health, later in
the spring, covering this data.
The methods used in analysis in gen*-
eral have been classical wet chemical
methods including centrifugation, steam
distillation, gas chromatography and
others. Metals analysis has been by di-
gestion and atomic absorption on a selected
group of 20 metals. In addition we are
working on a rapid elemental scanning tech-
nique using X-ray fluorescence. This
method will allow simultaneous determina-
tion of 50-60 elements with a minimum of
sample preparation. In fact, many samples
may be analyzed directly after a simple
homogenization.
Our current effort is directed toward
the development of well standardized proce-
dures for waste sampling and the incorpora-
tion of these procedures in a field manual
which will be suitable for use by regula-
tory agencies, waste generators, haulers,
and disposal sites. We also are attempt-
ing to develop a standard scheme for "waste
to standard methods" suitable for publi-
cation in manual form.
Now, as California begins a new stage
of hazardous waste regulation, with full-
time field inspection, surveillance and
sampling, the methods that have been devel-
oped will be put to severe test. The next
six months will determine whether they will
withstand the test.
The author would like to fully ac-
knowledge the valuable assistance of the
many co-workers at the U.S.C. Environ-
mental Engineering Department and the
California Department of Health, as well as
the financial assistance of the U.S.
Environmental Protection Agency.
50
-------
THE EFFECTS OF THE DISPOSAL OF INDUSTRIAL
WASTE WITHIN A SANITARY LANDFILL ENVIRONMENT
D. R. STRENG
SYSTEMS TECHNOLOGY CORPORATION
P.O. Box 24016
Cincinnati, Ohio 45224
ABSTRACT
In an effort to assess the impact of the practice of co-disposal
of industrial waste materials with municipal refuse, a project utilizing
3 ton experimental landfill test cells was undertaken. Concern has been
voiced that the addition of industrial wastes may result in the occur-
rence of various toxic elements in leachates and thereby pose a potential
threat to potable groundwater supplies.
A combination of municipal solid waste and various solid and semi-
solid industrial and municipal wastes were added to several test cells.
All material flows were accurately measured and characterized, for the
continuing study. Data are presented on the chemical and microbial
composition of the leachates and the gases produced.
INTRODUCTION
APPROACH
Environmental effects from
landfilling result from not only
soluble and slightly soluble
materials disposed of in the land-
fill but also from the products of
chemical and microbial transforma-
tions. These transformations
should be a consideration in manage-
ment of a landfill to the extent
that they can be predicted or
influenced by disposal operations.
The motivational aspects of this
project were -the lack of quanti-
tative data on the decomposition
processes under field conditions
and, in particular, the introduction
of solid and semi-solid industrial
waste.
In an effort to evaluate the
effects of the co-disposal of
industrial wastes materials with
municipal solid waste, nineteen
(19) large scale experimental test
cells, Figure 1, are being monitored
to achieve the following objectives:
1. Assess varying rainfall
regimens, 203.2 to 812.8 mm/yr
(8.0 to 32.0 inches per year), on
the rate of decomposition and the
resulting mass flow of gases and
leachates (cells 1-4).
2. Determine the impact of
municipal sewage sludge additions
on the rates of decomposition and
gas and leachate.
51
-------
3. Determine the impact on
decomposition rates by the addition
of a pH buffer (limestone) into the
waste during landfill construction
(cell 8) .
4. Determine the survival of
polio virus in a landfill environment
(cell 15) .
5. Determine if differences
in ambient soil temperatures signif-
icantly affect the rate of decom-
position in gas and leachate
production (cells 2 and 16).
6. Determine the impact on
decomposition in gas and leachate
production of the co-disposal of
six selected industrial residuals
with municipal solid waste (cells 9,
10, 12, 13, 14, and 17).
7- Determine the ability of
duplicate test cells to generate
similar physical and analytical data
(cells 18 and 19).
8. Determine the impact on
decomposition rates in gas and
leachate production by rapidly
bringing the municipal solid wastes
to field capacity (cell 11).
The test cells (experimental
landfills), employed for this
study were epoxy coated steel,
1.8 meter (6 ft.) in diameter and
3.6 meters (12 ft.) in height;
capable of holding approximately
3000 kilograms (6600 Ibs.) of
municipal solid waste in a manner
comparable to large area landfills.
The size of the test cells was
selected to minimize problems of
scaling factors generally associated
with smaller laboratory lysimeters
and to avoid the use of shredded
refuse. Larger test cells would
have been more costly to construct
and provide adequate instrumentation.
A total of fifteen (15) cells were
placed in the ground outdoors with
the remaining four (4) cells in an
enclosed bay area where higher
ambient temperatures were maintained.
Five (5) of the industrial waste
test cells (cells 9, 10, 12, 13, and
14) were located outside and one
(cell 17) industrial waste cell
inside. Prior to placement of any
solid and/or industrial waste, a
layer of silica gravel, 300 mm deep,
was placed in all cells as a base
for the solid waste and to allow
leachate to permeate to the drain
system. Laboratory studies of the
silica gravel showed it to be non-
reactive to leachate. All test
cells were coated with coal tar
based epoxy which was proven to be
resistant to leachate.
All test cells were loaded
simultaneously in a period of five
(5) days employing the loading
sequence outlined below.
Municipal solid waste from the
City of Cincinnati was obtained
directly from the packer truck and
deposited on a concrete mixing pad.
All trash bags were hand slit and
mixing was accomplished employing
a front end loader. A truck with
a removable bed was utilized to
deliver an 18.2 kg (40 Ib.) charac-
terization sample and an 11.4 kg
(25 Ib.) chemical, microbiological,
and moisture sample for subsequent
analysis for each 363 kg (800 Ib.)
increment of waste delivered to each
test cell. As solid waste was being
added to the test cells, the in-
dustrial or municipal sludge wastes
were added simultaneously. After
each increment of waste was added,
the solid waste or the solid waste
and sludge was mixed manually. Each
increment of solid waste was com-
pacted to a height of 300 mm (1 ft.)
and a density of 470 kg/cu.m (800 Ib/
cu.yd.) using a 21m (70 ft.) crane
with a 1318 kg (2900 Ib.) drop
weight. This sequence was repeated
8 times for each test cell to
provide 2.4 m (8 feet) or approxi-
mately 3000 kilograms (6600 Ib.)
of compacted solid waste.
The solid waste was then covered
with 300 mm (1 ft.) of compacted
clay and all cells were shielded
from both moisture and sunlight.
Temperature monitors are installed
throughout all cells and in the soil
at various locations within the
52
-------
CELL NO
WASTE
STREAM
AMT Mu?»
--tlLO
TOP
TYPE *
Of PTH '^CM
TCMP
PROBES
GiS
PROBES
TOTAL
SOLID ^L(
1
OPEN/
CLOSED
6 --
^2C3.J
1410
-X533S
b
3
•'
>C(i?6
t"
3 ,-,
3
.N
IFQM
(.1
3
4
-^•-'
I1;, ,
•5
3
5
^t WAGE
' r-
OPI1N,
CLOSE.O
Ib
,,-L ,',-
T,
3
6
SEWAGE
u so
01 [ rj
^C-FD
"
'Or •
3
J ,
7
SEWAGE
tMl
OP EM,
:LC^EC
!b
106?*:
3
3 ^
8
CACO,
.-0. /
OPEN
n '."''.LD
]L
'Jo t
3
3
9
PETRO-
LEUM
SLUDGE
1*1 H
^ ^
3
Jv
/o
BATT^fii
^- 1291
tN
16 --'
-<• /b
^
"
//
H i"i
C» ^ N.
' l.'V LO
•ex-
/foei'.
3
3-
/2
ELELTRC
PLATING
WASTE
f ;0>!
6 ^
/I06?
3
'-
13
NORGANtC
WASTE
( 4 L' 0 6
;a -x"
^
3
2
" "
14
CHLORINE
PROD.
1 LUDGE
'^
JUN
**•/
lOl.?6
5
2
/ '
/5
POLIO
OPEW^-
CLOSED
"/
(0676
6
3 ,
U
/6
^.
0676
6
3 ^
17
SOLVENT
BASED
SLUDGE
3^361^
x'|60'w:
16 IX'
28^ I
i067.£
6
3
x^"'
""
/8
16/
28.' JX"
-'Xl0e.7.6
6
3^
s*
13
I6x^
282IX
X057.6
6
3v
^
PEA GR1VEL-
CLA1
SILICA GRAVEL-
T.
>c
CELL LAYOUT PLAN
ELEVATION Yet- GAS PROBES ELEV.
FIGURE }. OPERATIONAL CHARACTERISTICS OF EXPERIMENTAL LANDFILLS.
53
-------
solid waste. This solid waste was
hand separated into nominal cate-
gories (paper, glass, food wastes,
etc.) and chemical and microbio-
logical analyses were performed on
the individual categories and on
composite samples. Water addition
to the cells at a rate of 406 mm (16
inches) per year is accomplished on
a monthly basis in accordance with
anticipated net infiltration for
the midwestern portion of the
country.
INDUSTRIAL RESIDUALS
UNDER STUDY
The industrial process residuals
evaluated included a refinery sludge
(RS) , battery production waste (BPW),
an electroplating waste sludge(EW),
an inorganic pigment sludge (IPW),
a chlorine production brine sludge
(CPBS), and a solvent based paint
sludge (SBPS). The physical char-
acteristics and amounts of industrial
wastes added to each cell are provided
in Table 1.
The refinery sludge is a by-
product of the refining of crude oil.
The waste material obtained is what
is termed API bottoms sludge. This
is a material resulting from a
gravity oil/water separator which
is very high in biological activity.
The battery production waste
was obtained from the manufacturer
of lead/acid storage batteries. The
waste is a composite from all phases
of a manufacturing operation with
the exclusion of the battery plate
assembly section itself. This
operation is a closed system from
which the waste material is shipped
to a smelter for the recovery of
lead. The waste obtained goes
through a neutralization process
before entering a settling pond from
which the sludge was obtained.
The electroplating waste was
obtained from a large plating firm
which employs the follpwing plating
processes: Chromium (Cr), Nickel
(Ni), Cadmium (Cd), Copper (Cu),
Iron (Fe) and Zinc (Zn). No tin
plating occurs at this firm. These
wastes were treated in various
categories. The chromium wastes
were converted to trivalent chromium
(Cr + 3) by the addition of sulfur
dioxide in an acid system (pH 3.0).
The pH was then raised to approxi-
mately 8.0 with caustic to precipi-
pitate the trivalent chromium. The
cyanide containing wastes were
treated by raising the pH of the
water with caustic and then breaking
down the cyanogen systems by the
addition of sodium hypochlorite.
All other acid wastewaters were
treated with base to elevate the pH
to a range of -8 to 9. The waste-
waters were then pumped to a lagoon
for settling. The sludge used was
a brown soupy material which con-
tained large amounts of liquids.
Inorganic pigment waste was
from a supplier whose main product
was titanium dioxide. It was
obtained by processing raw ore
through numerous production stages.
Wastewaters from the various manu-
facturing operations were pumped
to a single facility and treated
simultaneously. The water was
pumped to a primary settler during
which the pH was raised with base
and an alkaline precipitate forms.
This sludge was then dewatered and
the residue removed. The waste used
was a black solid material containing
very little moisture.
The chlorine production brine
sludge was obtained from a manu-
facturer employing the mercury cell
technique for chlorine liberation.
In this facility, the production of
chlorine was by the electrolysis of
sodium chloride in a mercury cell.
As the electrolysis proceeded,
chlorine was liberated at one elec-
trode while a sodium/mercury amalgam
was formed at the other. The
majority of the sludge (60 to 80%)
was from the brine saturator while
the remainder was from the clarifier
after settling. The sludge used
appeared somewhat moist, brown in
color, and extremely dense.
54
-------
TABLE 1. INDUSTRIAL WASTE PHYSICAL CHARACTERISTICS
Cell
9
10
12
13
14
17
Waste Type
RSC
^
EW6
IPWf
CPBS8
SBPSh
Moisture3
Content
79.00
89.25
79.53
51.75
24.11
24. 751
Amount Added"
1518
1291
1191
1420
2039
1604
Characteristics
High bacterial activity,
black moist
Grey-lg amount of
liquid
Brown, soupy
Black, solid, no odor
Very dense, no odor,
light brown, moist
Red to white color,
putty consistency, strong
odor
Percent by wet weight.
V.
cRefinery Sludge.
Battery Production Waste.
eElectroplating Waste.
fInorganic Pigment Waste.
^Chlorine Production Brine Sludge.
^Solvent Based Paint Sludge.
"""Mainly organic solvents.
55
-------
The solvent based paint sludge
used was representative of a paint
sludge produced in industries in-
volved in painting large numbers of
metal products. Paint overspray was
caught in a water curtain and was
pumped directly to a holding tank
for disposal with no pretreatment.
The material was very high in organic
solvents and was extremely viscous,
its color dependent upon the pig-
ments present.
The chemical analyses of these
waste materials, Table 2, indicated
that the sludges contained toxic
materials; their leachability, still
was not known.
Notable components of these
sludges were: Cu, Fe, Hg and
moisture for the refinery sludge;
Cu, Fe, Cd, Pb, asbestos; Sn, Sb
and moisture for the battery pro-
duction waste; Cr, Fe, As, Cd,
cyanide and moisture for the elec-
troplating wastes; Be, chloride,
asbestos, clay volatile fibers and
moisture in the inorganic pigment
waste; and Ni, Pb, chloride, asbes-
tos, Hg and clay volatile fibers
for the chlorine production brine
sludge.
LEACHATE AND GAS
MONITORING
All leachates are collected
anaerobically (under an argon stream)
from a centrally located observation
cell. Gaseous samples are collected
via gas lines leading to an instru-
mentation shed. Gas composition is
determined by gas chromatography.
All leachates are collected on a bi-
monthly basis and gas samples are
taken on a monthly basis.
Leachate Composition
Immediately after compaction,
small volumes (less than 1 liter)
of leachate were obtained from the
majority of the cells. Chemical
analyses of the leachate indicated
high concentrations of metals
present; organic analyses of these
same liquids indicated very small
amounts of carbon containing
material present. Based on these
chemical characteristics and the
time of appearance, it was con-
cluded that these initial volumes
of liquid were interstitial water
squeezed from the refuse, or refuse/
sludge mixture as a result of the
compactive effort and was not truly
leachate derived from infiltrating
water and decomposition processes.
After collecting the initial squeez-
ings from the test cells, no further
liquid was produced for a period of
approximately six months. At this
time leachate production was noted.
The occurrence of leachate was
attributable to several factors.
First, the number of available mois-
ture retention sites was reduced by
the addition of the high moisture
content industrial wastes, i.e., the
refining wastes, chlorine production
brine sludge, etc. For this reason,
field capacity was approached at a
much earlier date than originally
expected. Data indicate that field
capacity was reached in cell 14 and
was rapidly being approached in cells
12 and 13. Secondly, it appeared
there was channeling within the solid
waste/industrial waste test cells.
Channeling prolongs the time required
to reach field capacity, but allows
the early appearance of leachate.
The organic acid concentration
histories in leachates from refuse/
CPBS, refuse/IPW, refuse/EW and
refuse alone were similar, though
not identical; peak concentrations
occurred between the 8th and llth
months; Figures 2. Of these leach-
chates, that from the refuse/CPBS
had the lowest peak concentration,
i.e., approximately 61 percent of
the refuse peak. Leachates from the
refuse/EW and refuse/IPW had peaks
which were 38 percent greater and
29 percent greater respectively than
the refuse leachate. The short term
data compiled does not permit
determination of the significance of
these differences in peak organic
acid concentrations.
56
-------
TABLE 2. INDUSTRIAL WASTE CHEMICAL ANALYSIS3
Waste Cell Number
Total Solidsh
Total Volatile Solidsh
Moisture11
Cr
Ni
Cu
Fe
As
Be
Se
Cd
Cn
Pb
Clh
Asbestos^
Hg
Sn
Sb
Clay Volatile Fibers^
Zn
V
B
Ti
RSb
9
21.00
31.00
79.00
125
23
35001
5560
1.0
4.8
26.0
0.50
1.0
182
2.35
3.00
10.6
NAk
NA
40. 0
NA
7.20
NA
BPWC
10
10.75
7.94
89.25
155
32
1125
2950
72
1.8
180
29.0
4.2
3.48h
1.12
208
4.80
6800
1.32h
720
120
8.10
NA
EWd
12
20.47
8.98
79.53
1.56h
35
100
1.37h
460
0.25
4.50
38.5
460
267
1.35
23.0
14.7
NA
NA
86.0
NA
19.0
NA
IPWe
13
48.25
22.25
51.75
0.50
10
110
1000
3.4
20.2
16.0
10.5
3.4
120
10.0
45.0
7.60
NA
NA
185
40
28.5
NA
CPBSf
14
75.89
1.17
24.11
5.00
65
125
2000
14.5
<1.0
16.5
0.70
14.5
697
20.0
110
227
NA
NA
480
NA
1.70
<0.1
SBPSg
17
75.25
55.31
24.75
75.0
0.5
2.0
150
12.8
<1.0
7.60
0.50
12.8
12.6
0.75
9.00
16.7
NA
NA
65.0
NA
11.4
NA
aAll values in ppm unless otherwise specified.
bRefinery Sludge.
°Battery Production Waste.
^Electroplating Waste.
elnorganic Pigment Waste.
^Chlorine Production Brine Sludge.
^Solvent Based Paint Sludge.
^Percent by wet weight.
^Underlined values indicate maximum sludge concentrations.
jFibers/100 g.
kNot analyzed.
57
-------
30,000
25,000
20,000
15,000 •
10,000 •
5000'
45676
TIME IN MONTHS SINCE TEST CELL INSTALLATION
30,0001-
25,000 •
_ 20,000'
t
g 15,000 •
10,000 •
5000-
MS"
O O ELECTROPLATING WASTE
A—A INORGANIC PIGMENT WASTE
O—
-------
The organic acid concentration
data for both the refuse/BPW and
refuse/RS failed to display any
peaks. The graphical display of the
refuse/BPW data, Figure 2, is
indicative of microbial inhibition
within this cell. Gas analysis has
failed to indicate any vigorous
methane production while COD and TOC
data verified the low organic acid
content of this leachate. The
refuse/RS organic acid concentration
history, Figure 2, indicates extremely
vigorous decomposition occurring
which has kept the quantity of
organic acids low. Gas composition
data has shown conversion from
aerobic to methanogenic within
several months of solid waste place-
ment.
The total organic carbon (TOC)
histories for leachates emanating
from the refuse/CPBS, refuse IPW,
refuse/EW and refuse alone, Fig-
ure 3, were again quite similar.
Peaks occurred between the 5th and
7th months and again between the
9th and 10th months. The. decline
noted between the 7th and 9th month
was caused by the lack of moisture
entering the test cells during that
time period. The refuse/BPW and re-
fuse/RS, Figure 3, showed low con-
centrations of TOC for the reasons
alluded to earlier.
Concentration histories for
chemical oxygen demand (COD) in
the leachates of refuse/CPBS, refuse/
IPW, refuse/EW and refuse alone
were again very similar. Increasing
concentrations were noted as the
decomposition proceeded with a
greater rate of increase during
periods of water infiltration. The
concentration history of the refuse/
BPW behaved in a similar manner but
at a reduced level due to bacterial
inhibition. The refuse/RS indicated
low COD concentrations because of
the rapid digestion taking place.
Anaerobic production of organic
acids at a rate greater than their
assimilation by other organisms, or
greater than the indigenous buffer-
ing system causes the pH to range
from 4 to 6. This acidic, reducing
condition generally increases the
solubility of cations such as Cd,
Figure 4 and Fe Figure 5.
The Cd concentrations in leach-
ates from the refuse/IPW and the
refuse/CPBS climbed rapidly to 0.8
and 0.5 mg/1, respectively after
leachate production began. The Cd
concentrations from the refuse/CPBS
continued to increase, ultimately
to 1.2 mg/1, but at a slower rate.
In contrast, leachate from the re-
fuse only showed a comparable rapid
increase of Cd to a peak of 0.5 mg/1
when leachate modulation began, but
then rapidly decreased to a relative-
ly constant emission of 0.14 mg/1.
This decrease may be indicative of
the removal of readily soluble Cd
followed by a lower, but steady
release of less available Cd. The
limited data available for Cd in
leachates from the refuse/RS and
refuse/BPW has not shown such a peak,
possibly due to their later instal-
lation, and consequently the smaller
quantity of water added to these
test cells. The refuse/EW leachate
Cd concentrations also did not show
the rapid increase noted earlier;
possibly due to availability of the
Cd. The significance of the Cd data
are two-fold: all Cd may not be
equally available in the different
waste streams and where Cd was
readily available, in CPBS and IPW,
the leachate Cd concentration re-
mained 4 to 10 times greater than
for refuse only.
The influence of the reducing
conditions on cation concentration
was exemplified by Fe, Figure 5.
There was similarity in the con-
centration histories for all leach-
ates except for those from the
refuse/CPBS. The refuse/IPW ranged
from 9 to 25 percent greater and
the refuse/BPW ranged 16 to 25 per-
cent less than the iron in leachate
from refuse alone. The refuse/CPBS
derived leachates never exceeded
90 mg/1 or 28 percent of the iron
combined in the refuse. The high
chloride content, 20 percent, of the
CPBS was suspected to be important
in these results, but a relatively
59
-------
30,000
25,000 •
20,000
15,000 •
10,000 -
5000
SOLID WASTE
-J 1_
45678
TIME IN MONTHS SINCE TEST CELL INSTALLATION
11 1
30,000
25,000
20,000
15,000
10,000
5000
o—©ELECTROPLATING WASTE
A—AlNORSANIC PIGMENT WASTE
O—O CHLORINE PRODUCTION BRINE SLUDGE
4567
TIME IN MONTHS SINCE TEST CELL INSTALLATION
10 11
30,000
25,000
20.000
. 15,000
10.000
5000 -.
A-A PETROLEUM SLUDGE
O—O BATTERY WASTE
1234567
TIME IN MONTHS SINCE TEST CELL INSTALLATION
FIGURE 3. TOTAL ORGANIC CARBON CONCENTRATION IN LEACHATE
60
-------
1.4-
1.3-
1.2-
1.1-
1.0-
. .9-
f •'•
E .7-
.4-
.3-
.2-
.1-
SOIIO WASTE
1.5 —
1.4-
1.3-
1.2-
1.1-
1.0-
_ .9.
| .7-
" .6-
.5-
.4-
.3-
.2-
.1-
4 5 6 7 I
TIME W MONTHS SINCE TEST CELL INSTALLATION
.--&
O— 0~
O OHECTBOPLATIHC WASTE
A—A INORGANIC PIGMENT WASTE
O—O CHLORINE PRODUCTION BRINE SLUDGE
1.5-
1.4-
1.3-
1.2-
1.1-
1.0-
.7-
.6-
.4-
.3-
.2-
.1-
45678
TIME IN MONTHS SINCE TEST CELL INSTALLATION
A—A PETROLEUM SLUDGE
O—O BATTERT WASTE
45678
TIME IN MONTHS SINCE TEST CELL INSTALLATION
FIGURE 4. CADMIUM CONCENTRATION IN LEACHATE
61
-------
34 56 7
TIME IN MONTHS SINCE TEST CELL INSTALLATION
450r-
300-
150-
O—O ELECTROPLATING WASTE
/^—j^lNOBGANIC PIGMENT WASTE
O—O CHLORINE PRODUCTION BRINE SLUDGE
,©-_ ,-o o—o---
-er
4567
TIME IN MONTHS SINCE TEST CELL INSTALLATION
10 11 12
1234 567
TIME IN MONTHS SINCE TEST CEIL INSTALLATION
FIGURE 5. IRON CONCENTRATION IN LEACHATE
62
-------
high Cl content, 10 percent, in the
IPW did not impair leachability of
iron from that waste stream. In-
hibition of biological anaerobic
activity was discounted since organic
acid production was high, despite
rather high contents of Pb (697 ppm)
and Hg (227 ppm) in the raw sludge.
The chromium concentration his-
tories, Figure 6, did not resemble
those of the organic acids and Cd.
Initial high peaks in electroplating
waste and chlorine production brine
sludge of 36 and 25 mg/1 respective-
ly resulted from sludge squeezings.
Subsequent analyses showed a steady
decline to lower levels, generally
less than the 3 mg/1 reported for
the other refuse/industrial sludges
and refuse only leachates. The
latter peaked at .14 mg/1 near the
9th month after placement of the
waste.
The non-conformance of the Cr
data to increased solubility is
probably due to the absence of
readily available Cr in all of the
waste streams examined. The high
levels leached from the squeezing
of the EW and CPBS represent the
removal of readily available Cr.
Alternatively, the Cr may have re-
acted with the other waste materials
and remained in the waste mass.
Long term monitoring and ultimate
analysis of the leached refuse on
termination of the study should
determine the accuracy of the latter.
Other characteristics of the
leachate also were monitored, but
on a less frequent basis; conse-
quently, since leaching has just
begun, sufficient data for graphical
presentation is not available. Sus-
tained maximum concentrations of
several characteristics were deter-
mined, Table 3; but only those con-
centrations which occurred on a
somewhat continual basis have been
tabulated. All five of the leaching
refuse/industrial sludges yielded
more maxima that exceeded those from
refuse than did not. Leachate from
the refuse/RS showed As, B, Ni and
Zn occurring at lower concentrations
than found in the refuse alone. On
the other extreme, the leachate from
the refuse/CPBS had showed 12 con-
taminants exceeding those in the
refuse only leachate and 10 of these
were maxima for all leachates
studied.
High concentrations of vanadium
were found in leachates from refuse/
BPW; catalysts used in the manu-
facture of various batteries was
suspected as the source. Vanadium
was also found in leachate from
refuse/IPW. Its source was believed
to be the ore used during processing.
Generally, any sludge derived from a
processing operation employing ore,
rock, or salt will contain high
levels of inorganic contaminants.
Assays of these sludges indicated
they were high in aluminum, iron,
sodium, magnesium, chromium, vanadium,
tin, nickel, and antimony.
Maximum selenium concentrations
were found in the refuse/EW leachates
even though the raw EW residuals
contained the least. Antimony was
detected only in the inorganic pig-
ment waste. Tin was found in all
leachates, occurring at 5 to 53
times greater in the refuse/industrial
waste leachates than in the refuse
leachates. Stabilizers in plastic
materials may have contributed to
the tin in the raw refuse.
Asbestos was found in leachates
from the refuse/IPW and the refuse/
CPBS. In both cases, the asbestos
was found to originate from con-
taminants introduced to the material
flow during processing operations.
Surprisingly no asbestos was found
in the leachate from the refuse/BPW.
Cyanide was found in the refuse/
BPW leachate but was not detected in
the refuse/EW despite the fact that
the raw EW contained 100 times more
cyanide than the BPW.
Phenols were determined by a gas
chromatographic procedure which
identified all phenolic compounds
regardless of their substituent
groupings. Approximately 4 mg/1
were found in leachates from the
refuse whereas 23 mg/1, or almost
63
-------
<0r
30-
20-
10-
SOLID WASTE
-O O OO O
i 1
1 2
345678
TIME IN MONTHS SINCE TEST CELL INSTALLATION
9 10
40
0- O-
O O ELECTROPLATING WASTE
^—^INORGANIC PIGMENT WASTE
O O CHLORINE PRODUCTION BRINE SLUDGE
-l 1 J
1 2 3
45678
TIME IN MONTHS SINCE TEST CELL INSTALLATION
9 10 11 12
A—APETROLEUM SLUDGE
O O BATTERY WASTE
1 2 3 4 5 6 7 jj 9
TIME IN MONTHS SINCE TEST CELL INSTALLATION
FIGURE 6. CHROMIUM CONCENTRATION IN LEACHATE
64
-------
TABLE 3. SUSTAINED MAXIMUM CONCENTRATIONS OF LEACHATE CONTAMINATE3
Waste
Cell
Vanadium11
Arsenic^
Selenium^-
Antimony^-
Tink
Sulfurh
Asbestos11
Cyanide^
Aluminum"
Phenol11
Beryllium^
Leadk
Titanium11
Mercuryk
Boron11
Nickelk
Zinch
Summation
SWb
4
<0.03
12.2
<5
<5
150
674
<100
<1
<0.05
4.3
<0.1
1510
<0.1
19.7
18.1
1360
4.3
RSC
9
<0.03
<3.0 *
(13)
<5
(800)
NSAm
<100
<1
(1.2)
([22.9])
(0.9)
1450
<0.1
(31.2)
2.8
1010
2.1
4. (6) [1]
BPWd
10
([0.29])iJ
([30.0])
<5
<5
(1200)
491
<100
([1.2])
(8.1)
NAP
([45.0])
([3380])
<0.1
7.2
13.3
1319
(5.2)
1 (8) [5]
EWe
12
<0.03
<3.0
([230])
<5
(3000)
68
<100
<1
<0.05
NA
([30.0])
(1820)
<0.1
(26.9)
(22.0)
([3505])
0.5
1 (7) [3]
IPWf
13
([0.23])
13.0
([10.0])
([17])
(2400)
(846)
([6000])
5.0
(5.4)
NA
4.5
(2140)
<0.1
(67.1)
(24.0)
(1490)
([11.2])
0 (13) [5]
CPBS8
14
<0.03
([54.0])
<5
<5
([8000])
([3362])
([3000])
<1
([11.2])
NA
([48.0])
([6460])
(0.6)
([328])
([83.0])
([6020])
(8.0)
0 (12) [10]
aHigher concentrations may have been detected.
bSolid Waste.
°Refinery Sludge.
dBattery Production Waste.
Electroplating Waste.
Inorganic Pigment Waste.
gChlorine Production Brine Sludge.
1( ) indicates exceeded solid waste.
[ ] indicates exceeded maximums.
Underscore indicates less than solid waste.
mlnsuff icient sample available.
nFibers/£
Not analyzed.
65
-------
6 times that amount, were found in
the refinery waste.
Beryllium was found in leachates
from all the refuse/industrial
sludges but was not detected in
leachates from the refuse only.
Highest concentrations were reported
for CPBS, BPW, and EW; whereas the
largest amount, detected in the raw
sludges was in the IPW.
Lead was found in all leachates
at generally the same level, even
though the raw BPW contained roughly
100 times the lead of the other
wastes.
Titanium was found only in the
raw sludge of the CPBS and the
leachate from the refuse/CPBS.
Mercury was found in all sludges
and refuse/industrial sludge leach-
ates , though the maximum Hg in re-
fuse leachate was greater than in
refuse/BPW leachate. Not sur-
prisingly the greatest amount of Hg
detected was in the CPBS and leach-
ates from the refuse/CPBS.
The greatest boron quantities
were also recovered in the refuse/
CPBS but the raw CPBS initially
contained the least.
Zinc, nickel, aluminum and
sulfate were also detected in most
industrial sludges and leachates
derived therefrom.
It can be seen from the solid
waste chemical composition, Table 4,
that municipal solid waste itself
contains many of the same consti-
tuents that are of concern in
industrial sludges. For example the
metals (Cd, Cr), glass (As), fines
(Cr), ash, rock and dirt (Cr,).
Other studies have indicated the
presence of the following; glass
(Cr, Al, B, Sn, Ti, Zn, Be and Ni),
metals (Be), ash, rock and dirt
(Cr, Al, B, Pb). These actions are
generally present in the solid waste
in the fractions which constitute
the lowest percentage (i.e, metals
constitute only about 10% of the
total solid waste).
Gas Analyses
The gas composition of most of
the industrial waste cells was
relatively constant, Table 5. They
recently went from the anaerobic
non-methanogenic stage, (during
which carbon dioxide production
exceeded 90% by volume), to the
early phases of methane production.
One would expect to see the for-
mation of hydrogen with a decrease
in CO2 and beginning of methane
production at this time. The slow
production of methane is attributed
to the reduced cell temperatures
which has slowed down the microbial
degradation. This was verified by
the higher methane production with-
in cell 17 which was maintained in
a heated bay area.
•
The refinery waste, as it was
placed, contained large numbers of
bacteria (2.4 X 10^ aerobic colonies/
gram). These bacteria, obviously
acclimated to this waste, have begun
to degrade this material at a tremen-
dous rate as evidenced by the high
methane content.
Microbial Analyses
The microbial populations within
the cells changed considerably since
initiation of the study. It was
found that dieoff of the fecal
coliform group occurred while the
fecal streptococci continued to sur-
vive. More recently, fecal strepto-
tococci showed an apparently de-
clining trend as the industrial waste
cell leachates continued to show
higher metal concentrations.
Additional assays will be required
before any conclusive results are
known.
Summary
Six selected industrial wastes
admixed with municipal solid waste
were placed in test lysimeters.
Their effects upon leachate genera-
tion and composition, gas com-
position and microgiological activity
was determined.
66
-------
TABLE A. SOLID WASTE CHEMICAL COMPOSITION
Component
CODe
TKN
Total Phosphate
Lipids
Ash
Crude Fiber
Total Carbon
Inorganic Carbon
Organic Carbon
Sugar as Sucrose
Starch
Asbestos
Arsenic
Selenium"
Mercury^
Leadh
Beryllium11
Cadmium"
Ironh
Zinch
Chromium"
Manganese^1
Potassium"
Magnesium
Calciumh
Sodiumn
Paper
0.804
0.028
0.048
2.47
92.0
21.7
58.0
4.30
53.7
<0.1
3.40
NAf
<0.1
NA
NA
NA
NA
0.36
375
50.0
8.2
13.1
11.2
160
77.5
9.70
Garden
0.815
0.171
3.14
3.04
36.5
16.6
14.4
4.66
9.74
1.71
7.42
NA
NA
NA
NA
NA
NA
NA
330
106
1.1
194
0.135a
4175
0.830a
185
Metal
0.492
0.022
2.79
0.420
4.85
0.235
4.80
3.40
1.40
<0.1
<0.1
NA
<0.1
NA
NA
NA
NA
20.9
6.25a
175
15.3
870
1.00
80.5
<0.25
37.0
Glass
0.011
0.140
0.049
1.54
2.25
0.040
0.750
0.220
0.530
<0.1
<0.1
NA
10.2
NA
NA
NA
NA
2.7
3220
9.75
1.1
15.7
2.70
472
16.2
60.0
Food
0.754
3.09
10.4
13.8
41.6
10.5
19.5
2.58
17.0
6.08
8.57
NA
NA
NA
NA
NA
NA
NA
505
59.0
1.3
12.2
0.162a
377
0.465a
804
PRLTb
2.14
1.25
1.40
5.02
182
21.5
15.8
5.75
10.1
<0.1
3.42
NA
NA
NA
NA
NA
NA
1.81
444
118
2.0
12.1
98.7
289
912
143
Fines0
0.935
0.131
1.97
4.85
49.5
6.39
16.4
4.30
12.1
1.18
7.20
NA
1.2
NA
NA
NA
NA
4.2
0.392a
322
13.1
115
135
1.02a
2.11a
400
ARDd
0.040
0.119
4.48
1.52
19.6
5.85
13.4
7.80
5.60
<0.1
6.40
NA
3.6
NA
NA
NA
NA
4.5
0.340
181
10.1
177
555
2.63a
4.08a
0.209a
Diapers
0.720
0.138
2.65
2.26
96.0
13.7
44.5
0.740
43.8
<0.1
<0.1
NA
<0.1
NA
NA
NA
NA
0.25
99.0
343
0.5
5.90
750
279
360
0.110a
Wood
0.503
0.228
0.103
1.00
77.9
20.8
51.0
0.380
50.7
<0.1
0.78
NA
<0.1
NA
NA
NA
NA
1.6
0.378
59.4
1.1
50.0
90.0
253
590
572
Composite
0.520
0.247
2.32
2.84
25.8
11.3
24.8
3.08
21.8
3.50
16.2
-------
TABLE 4 (cont'd)
Component
Copper11
Nickelh
Moisture
MoistureJ
Composition
Compos it ion J
Paper
4.5
15.7
56.7
35.20
42.6
41.62
Garden
9.34
15.7
156.4
56.91
10.7
15.77
Metal
0.221a
115
8.80
6.18
12.2
8.21
Glass
2.54
19.0
2.00
1.65
12.2
7.83
Food
8.58
12.5
216.5
70.07
3,6
7.56
PRLTb
12.4
32.0
57.04
49.27
8.7
10.91
Fines0
35.8
33.2
123
49.36
2.9
3.58
ARDd
32.6
10.1
30.79
18.52
3.2
3.36
Diapers
4.14
3.36
133
66.28
1.3
2.47
Wood
38.2
27.0
21.43
17.10
2.6
1.99
Composite
31.6
10.1
Percent by dry weight unless otherwise sepcified.
"Plastics, rubber, leather, and textiles.
c<25.4 mm (1.0 in.).
^Ash, rocks, and dirt.
eg COD/g sample.
%ot analyzed.
^Fibers per gram.
hparts per million by weight.
•"-Plastics, rubber, and leather not analyzed.
3Percent wet weight.
-------
TABLE 5. GAS COMPOSITION DATA3
Cell
4
9
10
12
13
14
17
Contents
Solid Waste
Refinery Sludge
Battery Production Waste
Electroplating Waste
Inorganic Pigment Waste
Chlorine Production
Brine Sludge
Solvent Based
Paint Sludge
02
0.3
0.2
1.1
0.3
0.2
0.1
0.4
N2
29.9
26.4
22.3
16.4
2.9
16.6
47.0
CH4
0.0
17.1
0.0
1.1
0.0
0.0
4.9
CO 2
69.2
56.1
76.5
81.9
96.9
83.3
41.0
H2
0.0
0.0
0.0
0.0
0.0
0.0
6.4
Percent by Volume.
69
-------
A reduction in moisture adsorp-
tion capacity resulted from the
addition of semi-solid industrial
wastes. High concentrations of
contaminants leaching from the
various waste streams have been
noted.
Metallic ions may respond in
several ways in a landfill environ-
ment. They may:
1. Become very soluble due to
the acid/reducing conditions (Fe);
2. Be initially discharged in
the leachate due to already solubi-
lized cations, or readily leached
during initial placement (Cu, Cr);
3. Be converted, either chem-
ically or microbially, to a form
which is more amenable to transport
(Hg) .
The solid waste/refinery sludge
mixture is undergoing rapid decom-
position which has reduced the
quantity of organic matter in the
leachate. This indicates that more
complete decomposition may result
from the addition of certain re-
finery wastes to municipal solid
waste.
70
-------
PRACTICAL RECOMMENDATIONS FOR OIL SPILL DEBRIS DISPOSAL:
A PROGRESS REPORT
J. S. Farlow
U.S. Environmental Protection Agency
Oil & Hazardous Materials Spills Branch, lERL-Ci
Edison, New Jersey 08817
D. E. Ross
SCS Engineers, Inc.
4014 Long Beach Boulevard
Long Beach, California 90807
ABSTRACT
Many oil spill cleanup efforts include the disposal of a significant quantity of
oily organic and inorganic debris. Because spills are emotion-charged events, debris
disposal is often impeded by the somewhat exaggerated fears of local inhabitants and
officials. In some cases on record, final disposal plans could not be implemented until
more than a year after the spill. It is felt that a written description of the techni-
cal options might help alleviate the difficulties. The U.S. Environmental Protection
Agency has retained SCS Engineers, Inc. to prepare a detailed, practical how-to-do-it
manual for oil spill debris disposal and to make an accompanying film for State and lo-
cal officials. A literature search has been carried out, sites for confirming field
studies chosen, and some film footage taken. The bulk of the field work is scheduled for
early spring. The completed manual and film are due in early summer 1976. Present rec-
ommendations for disposal of unrecyclable material include soil cultivation, incorpora-
tion into an approved sanitary landfill and individual burial. A description of the
rationale proposed for selecting one method over another and findings to date are pre-
sented.
THE PROBLEM
You all have read media accounts of
oil spills, seen pictures of sticky work-
ers cleaning up blackened beaches and felt
sorry for the wild birds being de-oiled by
toiling volunteers. Despite the signifi-
cant reduction in the number of spills,
achieved in part by the effective spill
prevention regulations being administered
by the U.S. Environmental Protection
Agency (EPA), the unfortunate truth is
that oil will continue to be spilled so
long as humans and equipment are involved.
Published Coast Guard figures show that
11,435 spills totaling 15,808,436 gallons
of oil were reported in 1974.'-'-)
In the course of cleaning up a spill,
some oily debris is almost inevitable. The
debris may be chiefly biodegradable mate-
rial, such as seaweed, leaves, driftwood or
grasses; or may be chiefly non-biodegrad-
able, such as sand, gravel, shingle, rocks,
beer cans, truck tires or plastic; or may
be almost any combination. If a spill gen-
erates a large volume of debris, the debris
may be stockpiled at one or more temporary
locations until a decision about final dis-
posal can be made.
The selection of a means of disposal
should not be made lightly. First, the
volume of material from a single spill may
amount to as much as 10,000 dump truck
loads. Next, even a small quantity of oil
71
-------
working its way into the drinking water
supply could produce taste and odor prob-
lems. Finally, and perhaps most signifi-
cant here, by this stage in a spill the lo-
cal population has been semi-traumatized
by the media coverage and by the shock of
seeing their very own land oiled up. A
typical reaction to this nightmare-come-
true is to want all evidence of it far a-
way, out of sight, instantly. The thought
of having the debris remain nearby, even in
the local landfill, is unthinkable. And
naturally, all the other, unaffected towns
in the region who've been watching the news
definitely don't want the debris transport-
ed to their landfills either.
Since the debris is often stockpiled
in the local swimming beach parking lot,
a real sense of the urgency of the problem
doesn't develop until the bathing season
approaches. In some cases, the impasse
remains until finally some state or
Federal land can be found to receive the
debris.
THE PROPOSED SOLUTION
Several EPA regional spill cleanup co-
ordinators have expressed the feeling that
state and local officials would be greatly
assisted in their efforts to dispose of the
oily debris locally if a written, rational,
practical, state-of-the-art description of
the options were available. Such a doc-
ument, especially if Federally sponsored,
would provide a comprehensive source of
authority which local officials could rely
upon for support in making their techni-
cal and political decisions.
In late June 1975 the EPA Oil & Haz-
ardous Materials Spills Branch in Edison,
New Jersey retained SCS Engineers to pre-
pare a practical, state-of-the-art, how-
to-do-it manual for the land disposal of
oily debris. The manual is to be based
both upon an extensive literature search
and upon confirming field work. The manu-
al is to contain:
a. A thorough discussion of the sci-
entific and engineering rationale (cross-
referenced to published literature and
site visits performed under this contract)
for selecting these recommended detailed
directions .
b. Detailed directions for select-
ing sites at which oil spill cleanup de-
bris may be disposed of in an environmen-
tally safe manner.
c. Detailed directions for preparing
the sites and for placing and treating oil
spill cleanup debris at the sites selected
in an environmentally safe manner.
d. Detailed directions for operating
the site and reworking the oil spill
cleanup debris deposited there (if desir-
able and/or necessary) so as to ensure
minimal environmental damage and maximal
environmental benefits.
e. Detailed directions for monitor-
ing the oil spill cleanup debris, the dis-
posal site and its vicinity so as to be
able to detect any possible environmental-
ly damaging situation early.
f. Detailed directions for remedial
measures to correct those potentially
damaging situations discovered by the mon-
itoring.
g. A thorough discussion of the po-
tential benefits and damages that may re-
sult from adhering to the above direc-
tions .
h. An appendix containing the out-
line of a suggested training course for
disposal site operations personnel in
these techniques recommended for disposing
of oil spill debris.
i. A technical appendix containing a
detailed account of sites visited, infor-
mation gathered, field work performed,
data obtained and conclusions drawn, to-
gether with the rationale for the actions
undertaken.
In addition, SCS is to prepare a
short, color summary film for State and
local officials. Both the film and the
manual are scheduled for completion in
early summer 1976.
72
-------
PROGRESS TO DATE
Literature Search
The chief objective of the information
gathering phase is to determine the state-
of-the-art of knowledge of the environmen-
tal effects of oil spill debris disposed
of on land. Efforts were organized to ob-
tain the following information:
- Properties of oil spill cleanup de-
bris;
- Integration of oil and oil emulsions
with soil;
- Degradability of oil spill cleanup
debris;
- Effects of oil disposal on vegeta-
tion; and
- Status of existing oily waste dis-
posal technology.
Materials from the literature were,
and continue to be, expanded and supple-
mented by data gathered through personal
interviews with various knowledgeable rep-
resentatives of industry, government, and
the academic community. A number of spills
and spill sites, debris disposal areas, re-
finery waste disposal areas and disposal
method test plots have also been visited.
Field Studies
Because most of the literature-based
information and data obtained from personal
interviews were not specific to oil spill
debris, field studies are planned to try
to obtain information pertinent to oil
spill debris disposal sites and to confirm
ideas in the literature.
Three case study sites have been se-
lected. The first site is in northern
California and involves straight burial.
The second is in Rhode Island and involves
an above-ground landfill. Both of these
contain oil spill debris only. The third
site is in Utah near the Great Salt Lake,
involves the soil cultivation of lube oil
from a waste lagoon and will be described
by Hal Snyder and George Rice in an inter-
esting presentation tomorrow.
We would like to find a fourth site to
investigate, but are having difficulty in
locating interesting ones about which suf-
ficient background information exists. If
any member of the audience has a sugges-
tion, please contact us.
The field work will begin this March.
Soil and debris samples will be collected
both from the surface and during the
drilling of about 5 wells at each disposal
site. Soil and oil spill debris samples
will be analyzed for oil content, total
extractable hydrocarbons, various ions,
and biological activity. Soil samples
will also be tested for permeability and
grain size distribution. In addition,
water and leachate samples will be col-
lected where appropriate and analyzed pri-
marily for oil content.
The samples will help determine:
a) whether the oil remains at the
disposal site
b) how much oil is present
c) the character of the oil at dif-
ferent locations within the site.
From these, an assessment of the effec-
tiveness of the disposal method may be
made.
Film Making
Some background film footage has
been obtained. The main work will be ac-
complished this spring.
PRELIMINARY CONCLUSIONS
On the basis of information review-
ed and interviews conducted thus far
during the project, the following conclu-
sions can be drawn.
1. Knowledge of important aspects of
oily waste interaction with the environ-
ment is generally lacking. Various tests
have been run at refineries and elsewhere
indicating that natural vegetation re-
establishes itself on oily waste treated
plots within one growing season. Rela-
tively little work has been done regard-
ing the effect of oily wastes on vegeta-
tion growing on a disposal area. Some re-
ports indicate that food crops may be
grown and safely eaten as little as three
years after oil has been placed on the
soil. Others suggest that no edible crops
should ever be grown on oil-treated lands.
This question requires resolution.
2. Only limited study of oil spill
debris disposal or of the debris' effects
on the environment has been conducted to
date. However, existing information on
73
-------
land disposal of oily refinery wastes and
crude oil is applicable to the problem of
oil spill debris disposal.
3. Debris from a single oil spill may
consist of either essentially one material
or a large variety. The range of sizes of
components may be widely varied or the re-
verse. The debris itself may or may not be
largely biodegradable.
4. The oil mixed with the spill de-
bris may have a relatively high metals con-
tent if it has been used for lubrication,
and its other properties may vary over a
wide range depending upon its origin and
history. The quantity of oil mixed with
the debris may range from almost none to
over 10 percent.
5. An attempt should be made to find
a use for as much of the debris as possi-
ble. Examples of uses are oil reclamation
and road bed construction.
6. Oil is an organic substance and as
such is subject to biodegradation. Biode-
gradation occurs fairly readily under aer-
obic conditions. Oil degradation in an
anaerobic environment is at best very slow,
and "buried oily waste will remain un-
changed for hundreds of years."(2) Over
100 species of bacteria and fungi commonly
found in the Temperate Zone are known to
attack one or more fractions of crude oil.
Suitable oxygen, nutrients, water, and
temperatures are also required. Data re-
garding oily waste degradation rates have
been obtained primarily from studies of
relatively homogeneous refinery waste.
Oil spill cleanup debris may be very dif-
ferent from oil refinery waste and may or
may not exhibit the same degradation rate
characteristics. Studies have shown that
oily wastes continually exposed to oxygen
have degraded to relatively imperceptible
levels of oil in periods ranging from a re-
ported six months up to three years. The
actual time depends upon disposal methods,
oil type, climate, and other site-specific
factors. Degradation rates on the order of
800-1000 barrels pure oil per acre per year
have been achieved.(2)
7. The soil cultivation process has
been used routinely for years to dispose
of oil refinery tank bottoms and separator
sludge wastes. Initially, the land is
cleared, fertilizer added and the area
roto-tilled to break up clumps and
distribute the fertilizer. A 6 inch
thick layer of sludge is added (dumped
from trucks at the edge of the field and
distributed by bulldozer) and left to de-
water by evaporation. When de-watering is
largely complete (several weeks), the
sludge is roto-tilled to mix it thoroughly
and evenly into the soil and fertilizer.
Roto-tilling is repeated at varying inter-
vals (from bi-weekly to quarterly) during
the growing season. The initial amount of
fertilizer and any later additions depend
upon the results of soil analyses. Roto-
tilling provides better mixing and is def-
initely superior to disking. The size and
nature of the debris must be such that it
will not damage the roto-tiller. Oil deg-
radation will be slower during the first
season until the bacteria numbers build up.
Degradation is often essentially complete
in less than three years. Because of var-
ious uncertanties, it seems best at the
present time to recommend that no edibile
crops be grown on land used for soil cul-
tivation of oil. Considerable land exists
which has a low slope and is not suitable
for pasturage or crop production. In more
built up areas, soil cultivation can be
practiced on top of completed portions of
landfills if suitable precautions are
taken to prevent penetration of the upper
impermeable layer. Some 8,000 cubic yards
per year of refinery separator sludge have
been handled in a 16 acre coastal Texas
site.(3)
8. Oil spill debris may be incorpora-
ted into existing sanitary landfills or a
specially constructed landfill, or buried.
In these anaerobic environments the oil
will degrade only slowly at best. Because
the potential for leaching is present for
decades, it is felt that these disposal
methods are inferior to the soil cultiva-
tion process. Measures must be taken to
ensure that leachate can never migrate from
the site. Careful site design and proper
materials of construction can reduce the
problem. These disposal methods do have
the advantage that they can accept both
large individual pieces of debris and non-
biodegradable synthetic materials. If one
of these anaerobic disposal methods is to
be used, an existing sanitary landfill
(assuming it is properly sited, construct-
ed and operated) is the first choice be-
cause the land has already been committed
to disposal operations. The other two
methods require the diversion of "new"
land.
74
-------
9. Research into the interaction of
oil and the environment is increasing
rapidly. Spurred by the public's concern
over oil spills and environmental pollu-
tion in general, refineries and univer-
sities are investigating more intensely
the pertinent factors. This suggests that
systems presently recommended for land
disposal should be reviewed periodically
in the light of new data that may be de-
veloped.
References
1. Polluting Incidents In and Around U.S.
Waters, Calendar Year 1974, U.S. Coast
Guard, Dept. of Transportation, Washington,
D.C.
2. Grove, G.W., "Use Gravity Belt Filtra-
tion for Sludge Disposal." Hydrocarbon
Processing, pp. 82-4 (May 1975).
3. Johnson, J.M., Exxon Company, U.S.A.,
private communication (1975).
75
-------
INDUSTRIAL HAZARDOUS WASTE MIGRATION POTENTIAL
M.J. Houle, R.E. Bell, D.E. Long, J.E. Soyland
Department of Army, Dugway Proving Ground, Dugway, Utah 84022
M. Roulier
U.S. Environmental Protection Agency, Solid and Hazardous Waste Research Laboratory,
National Environmental Research Center, Cincinnati, Ohio 45268
ABSTRACT
The migration of hazardous materials in soil is largely controlled by the physical
and chemical composition of the soil upon which the waste is placed. However, differ-
ences in waste composition and leachability cause large differences in migration of speci-
fic elements or compounds through a soil. This is demonstrated by comparing the migration
of cadmium, leached from four different industrial wastes, through one type of soil. The
wastes were nickel-cadmium battery, electroplating, water base paint and inorganic pig-
ment wastes. The soil used in these experiments was Davidson (N. Carolina) clay soil
which is classified as an Ultisol. information as to difference in penetration and dis-
tribution of the cadmium in the soil is presented and related to differences in the
wastes.
INTRODUCTION
Industrial processes along with air
and water pollution abatement activities
generate tremendous and ever increasing
amounts of solid and semi-solid wastes
which are disposed of in lagoons and land-
fills. These wastes often contain hazard-
ous substances that can be released from
these wastes by leaching or decomposition,
and then migrate down through the soil in-
to potable water supplies. Instances have
been reported of human and animal poison-
ing due to leaching of toxic substances
from wastes placed in disposal sites and
subsequently migrating into underground
water (1,2,3). It is therefore important
to examine the potential of these toxic
materials to move through various types of
soil.
The migration of toxic substances is
influenced by the chemical and physical
composition of the underlying soil. How-
ever, the chemical composition of the
waste itself establishes the ionic ex-
change capabilities of the resulting leach-
ate, which can produce vast differences in
the migration of a toxic substance even
through one type of soil. The effect of
waste is shown here by leaching four dif-
ferent industrial wastes with water and fol-
lowing the migration of cadmium through a
clay soil. (Cadmium was chosen as an exam-
ple from a larger study where a number of
toxic metals were leached from industrial
wastes by water and by landfill leachate
and passed through two types of soil.)
METHODS AND MATERIEL
Description of the Industrial Wastes
Nickel-Cadmium Battery Production Waste
This waste arises from the washing of
nickel and cadmium electrodes. The wash-
ings are quite alkaline (pH 11-12) and con-
tain nickel and cadmium hydroxide precipi-
tates. Most of the precipitates are re-
claimed. However, some "fines" are lost in
the waste water. The industrial plant
where the samples were collected disposes
of the wastes in a lagoon. The first waste
76
-------
sample was collected from the lagoon at the
outfall of the waste line. A second waste
sample was collected from the lagoon itself.
It was found that the waste "ages" rapidly
in the lagoon and a considerable quantity
of the excess basicity is washed out during
standing in the lagoon. When a sample of
aged waste was mixed with water in a ratio
of one part waste to two parts water, the
resultant pH was 9.1. Fresh waste mixed in
the same proportions gave a pH >11. This
shows the results of aging and also demon-
strates differences that are likely to occur
in samples from a single location. The
waste sample from the lagoon was used in
this study.
The cadmium content of the waste was
52 percent by weight. The cadmium was most
probably present in the waste as the hy-
droxide salt.
Electroplating Waste
The electroplating waste results from
plating, phosphatizing, and metal cleaning
operations. Metals are precipitated from
the waste water by the addition of lime or
caustic soda. The cadmium content in the
waste was 0.8 percent by weight. The cad-
mium probably exists in the waste as the
hydroxide. However, it may also be present
as cyanide complexes. A trace of cyanide
was found in the waste.
Inorganic Pigment Waste
Pigment manufacture waste water con-
taining dissolved and suspended solids is
adjusted with sulfuric acid to pH 3. Sul-
fur dioxide is added to reduce the hexava-
lent chromium, the pH is raised to eight
with slaked lime, sodium sulfide is added,
and the excess sulfide is precipitated by
ferrous sulfate. A flocculating polymer is
then added, the precipitate filtered off
and the liquid is discharged. The cadmium
content of the filter cake is 0.17 percent
by weight. The cadmium is probably present
in several forms in the waste. Some may be
hydroxide salts and some may exist as cad-
mium sulfide or other cadmium pigments.
Water Base Paint Waste
Waste and equipment washdown waters
are treated with sodium sulfite, slaked
lime is added to adjust to pH 10, alum and
a flocculating polymer are then added and
the mixture is allowed to settle. The
liquid is discharged and the solids pumped
into a lagoon. The cadmium content in the
dried waste was very low, 0.05 percent by
weight. The cadmium probably results from
the pigments added to the water base paint
and is in the forms previously described
under pigment waste.
Preparation of Waste Columns
The wastes and the soils were packed
in separate columns to allow tapping off
samples of waste column leachates (Figure
1).
Soil Column
Soil
Effluent
Waste Column
Leachate
Industrial
Waste
Figure 1. Column configuration.
The columns were made from 37 mm I.D. glass
tubing with a 8 mm diameter tip on the bot-
tom. A piece of glass wool was placed over
the bottom hole and covered with washed
quartz sand. One hundred grams of the
waste were then packed into the column, oc-
cupying a depth of 10-13 cm, depending upon
waste. The waste was covered with 1 cm of
77
-------
sand and a thin layer of glass wool and
then fitted with a stopper containing a 3-
way stopcock which allowed either sampling
the leachate after it passed through the
waste or directing it on an upflow path in-
to the soil column above. An upflow ar-
rangement was used to maintain saturation,
to minimize channeling, and to permit bet-
ter flow control at the desired flowrate
of 0.5 to 1.5 pore volume per day.
The ease with which water penetrated
the waste column varied greatly between
the wastes. At the 7 foot head pressure
used for these experiments, water quickly
penetrated the water base paint and inor-
ganic pigment wastes, but passed through
the fine, densely packed electroplating
waste very slowly. The nickel-cadmium
battery waste was so impervious that it
was mixed with an equal weight of washed
quartz sand to obtain a useful flowrate.
Description of Soil
Davidson soil, an Ultisol, was used
in this investigation. It is a dark red,
clayey, Kaolinitic, thermic Rhodic Paleu-
dult that was collected from the B-horizon
at a depth of 30 to 100 cm by personnel
from the Department of Soil Science, North
Carolina State University, Raleigh, North
Carolina. This soil is slightly acid and
contains over 60 percent clay; the re-
mainder is evenly divided between silt and
sand. Water penetrates columns of this
soil at a moderate rate.
Preparation of Soil Columns
Davidson soil was dried, mixed, and
sieved to remove roots and stones, using
that which passed a 20 mesh screen. Col-
umns were packed with 160 g of soil to a
density of 1.5 g/cc which gave a 10 cm
depth. The pore volume calculated for
this amount of soil was 38 ml, after de-
ducting 10 percent of the volume as being
unexchangeable with water percolating
through it.
Analyses
Column Eluates
The pH and electrical conductivity
were measured in each sample, HNC>3 was
then added and the cadmium content deter-
mined by atomic absorption spectrophoto-
metry using an air-acetylene flame. The
lower detection limit for waste leachates
and soil digestates was 0.02 mg Cd/1. Lit-
tle interference in the analysis was found
when cadmium was added to control soil
leachates or soil digestates.
Soil Digestion
At the completion of each leaching ex-
periment, the soil column was frozen and
cut into four equal sections. The first
section (first to receive the waste leach-
ate) was further divided in half. Each
section was dried at 105OC, weighed, pul-
verized, and blended. A one gram sample of
each section was transferred to a 400 ml
beaker, 20 ml of fresh aqua regia was added,
the beaker covered with a watch glass, and
the sample digested by boiling to incipient
dryness. After cooling, the watch glass
and beaker wall were washed down with dis-
tilled water and the volume was adjusted to
25-30 ml. Two ml of concentrated HNO3 were
added and the sample brought to a slow boil
for 15 minutes. Upon cooling, the sample
was filtered through Whatman 40 filter pa-
per into a 100 ml volumetric flask. The
residue was washed with IN HN03 and then 5
times with distilled water. The filtrate
was diluted to 100 ml and analyzed by atom-.
ic absorption spectrophotometry.
RESULTS AND DISCUSSION
Preliminary Waste and Soil Studies
'There is a large difference in the
solubility of various components contained
in the wastes. Table 1 shows the total
solids dissolved from a 1:2, waste:water
slurry that was mixed for 24 hours.
TABLE 1. DISSOLVED SOLIDS
Total Dissolved Percent of
Solids (mg/1 ex- criginal
Waste tract) Waste
Ni-Cd Battery
Electroplating
Pigment
Paint
3,270
1,530
540
470
6.53
3.07
1.08
0.93
The electroplating waste is about half
as soluble as the battery waste while the
pigment and paint wastes are far less solu-
ble. However, significant portions of the
78
-------
pigment and paint wastes are organic. This
may be responsible for the reduced water
solubility.
The water soluble fraction of the
paint and pigment wastes were analyzed for
carbon and nitrogen, giving the results
in Table 2. These indicate that some of
the organics in the wastes are water solu-
ble.
TABLE 2. CARBON AND NITROGEN CONTENT OF
WATER EXTRACTS
Waste
Percent
Carbon
Percent
Nitrogen
Pigment
Paint
2.3
16.5
0.7
0
Preliminary studies were conducted
using five different soils to determine
which soil removed the largest amount of
cadmium from the waste leachates. The
soils used in addition to Davidson were
Kalkaska, Anthony, Chalmers, and Nicholson.
Davidson was found to be the most effect-
ive; this is somewhat surprising because
its clay fraction is predominately kaoli-
nite. The soil has a relatively low ex-
change capacity (9 meq/100 g). In con-
trast, Nicholson soil contains a large
clay fraction composed predominately of
vermiculite and has a high exchange capa-
city (37 meq/100 g). However, it has been
suggested by Fuller (4) that iron present
in soils is effective in removing some me-
tals from waste leachate. Davidson soil
contains 17 percent ferric oxides (5).
Soil Column Studies
Nickel-Cadmium Battery Production Waste
Figure 2 shows that a high concentra-
tion of cadmium was leached from the nickel-
cadmium battery production waste throughout
the study, starting at approximately 28,000
(jig Cd/pore volume and gradually decreasing
to approximately 8,000 (Ag Cd/pore volume
after 26 pore volumes of water had passed
through the waste column. This high chal-
lenge to the soil resulted in substantial
quantities of cadmium penetrating the soil
column after only two to three pore volumes.
Figure 2. Penetration of Cadmium Leached from Nickel-Cadmium Battery Wastes .Through
Davidson Soil.
79
-------
The amount penetrating increased until five
pore volumes had passed through the soil and
then steadily decreased to a low level for
the next eight pore volumes. Apparently,
the cadmium was competing initially with
other soluble materials in the waste leach-
ate for absorption and/or exchange sites
resulting in a substantial quantity washing
through the soil. This is indicated by the
specific conductance of the soil effluent
which initially was very high (40,000 mi-
cromhos) but which decreased rapidly during
the next ten pore volumes. Similarly, the
amount of cadmium penetrating the column
dropped off even though the challenge concen-
tration remained very high and fairly steady.
Most of the cadmium was absorbed until the
soil became saturated and then breakthrough
was observed. If we use the definition of
"breakthrough" as that point when the con-
centration of metal in the soil effluent
equals the concentration of metal challeng-
ing the soil column, breakthrough was
achieved after 19-23 pore volumes.
Shortly after it was established that
the soil was saturated with respect to cad-
mium, the waste column was removed and the
soil column was flushed with distilled
water. This was done to gain information
as to how cadmium flushes from a soil satu-
rated with it. The results are shown in
Figures 2 and 3.
After the water leach was started, the
cadmium content in the soil effluent re-
mained very high for four to five pore
volumes. The level then dropped sharply to
a relatively low level. The water flush
was continued for 100 pore volumes. The
cadmium concentration stayed at approximate-
ly 100 mg Cd/pore volume for 50 pore volumes,
then increased to 250-300 p, g Cd/pore volume
and remained at this concentration until the
experiment was ended. The specific conduc-
tance of the soil effluent paralleled close-
ly the cadmium content in the flush samples.
Although the cadmium breakthrough, as
defined, did not occur for 19 pore volumes,
the safe drinking water level (O.Olug/1)
was exceeded continuously (6). This is also
true of the cadmium found in the soil ef-
fluent collected during the water flush.
HBB.BBT
300.00-
200.00--
0.00--
N-IM>flVIKDN SOIL
DUT
SPECIFIC OUUHICfflNO:
E0.00 TI
HOB
2B.00
PDRE VDLUHt:
Figure 3. Water Flush of Cadmium from Davidson Soil.
80
-------
This demonstrates the migration potential
of cadmium from the waste and indicates
the hazard that might result from improper
disposal.
At the end of the experiment, the
soil column was frozen, sectioned, and the
soil digested. The amount of cadmium in
the soil was found to be very high and
fairly uniformly distributed except for
the first half section. The cadmium in
this section was the lowest due to the pro-
longed water leach. The results are shown
in Figure 4; they provide some insight into
the problem of reclaiming a disposal site
if the underlying soil became saturated
with components from a highly soluble
waste.
For comparison, and to re-emphasize
the importance of the soil underlying a
disposal site, Figure 5 shows the ease
with which cadmium breaks through Kalkaska
soil, which is about 90 percent sand. The
challenge concentration was similar to
that used during the Davidson soil experi-
ments. Breakthrough occurred within the
first pore volume as compared to 19 pore
volumes with the Davidson soil column.
Electroplating Waste
The cadmium leached from the electro-
plating waste behaved much differently for
Davidson soil as shown in Figure 6. Al-
though the cadmium challenge concentration
was considerably lower than that from the
battery waste, the soluble ion content was
initially very high (conductance was 25,000
micro-mhos) . An initial surge cf cadmium
leached from the waste but it reached a
steady level after eight pore volumes. The
soil did not become saturated with cadmium
even though the waste challenge was contin-
ued for 30 pore volumes. This indicates
that cadmium from the electroplating waste
is fairly immobile in Davidson soil. The
concentration of cadmium in the soil efflu-
ent was very low (1-5 u.g/pore volume) and
nearly uniform throughout the challenge
period. When the column was placed on water
flush, the cadmium concentration in the soil
leachate samples dropped immediately to be-
low the detection limit of the atomic ab-
sorption method.
3
i
in
2.H&-
I.E&-
D ,Uu '
0.00-
IHS-ailL
OIMIUH IN DflVIDSON SOIL
IR IB
Figure 4. Distribution of Cadmium from Nickel-Cadmium Battery Waste in Davidson Soil
Column.
81
-------
HJIHIBt £
3.0ft
2.00-
1.00--
H-S-KHUffiffl MIL
t OOHIUH OUT
D OOHIffl IN
- SPECIFIC onountma
I0t H XT EJ0
-- H.J0
-• 3.0
POfiE VDLUHE
Figure 5. Penetration of Cadmium Leached from Nickel-Cadmium Battery Waste Through
Kalkaska Soil.
. BBr
TK.W-
75.00--
SOIL
10! H XT
I CHDHllffl DUT
o CHDmun in
- SPECIFIC
2.IB
I.HH
.7B
PDRE VOLUME
Figure 6. Penetration of Cadmium Leached from Electroplating Waste Through Davidson Soil,
82
-------
As seen in Figure 7, when the soil
column was sectioned and digested nearly
all the cadmium was retained in the first
half section, with only a small amount dis-
tributed in the second half section. The
cadmium found in sections 3 and 4 was the
same as that found in control columns of
Davidson soil that were flushed with a com-
parable volume of water. This shows that
the soil has the capacity to absorb a great
deal more cadmium leached from this type of
waste. It must be remembered that the
waste initially contains many soluble ions.
However, this did not result in a early
burst of cadmium penetrating the soil. The
cadmium is probably attenuated in the soil
through absorption. However, precipitation
may also account for part of the attenua-
tion. Because of the low level of cadmium
leached from the waste after the first
eight pore volumes, it is concluded that
little hazard would result from cadmium
contained in this type of industrial waste.
Inorganic Pigment Waste
Completely different results were ob-
tained from the studies using inorganic
pigment and water base paint wastes. A
much lower cadmium challenge was obtained
from both wastes and the specific conduc-
tances of the soil effluents were much low-
er.
The results from the pigment waste
study are shown in Figure 8. The initial
output of cadmium in the waste leachate de-
creased gradually to the detection limit
(lp,g Cd/pore volume) after 40 pore volumes.
Cadmium came through the soil column after
15 pore volumes and its concentration in the
soil effluent remained higher than the chal-
lenge concentration for the next 15 pore
volumes. After a total of 40 pore volumes
of waste leachate had passed through the
soil, cadmium decreased to a non-detectable
level except for some penetration at 83
pore volumes.
Digesting the soil after completing
the challenge period revealed that no cad-
mium was retained on the Davidson soil.
The results obtained from challenge
studies using water-base paint waste are
shown in Figure 9. The cadmium content in
I.0&T
60.00--
40.00--
20.00--
O0-
H-2B-5DIL
CRDMIUH IN MVID511N SOIL
3
5ECT1DN NO IH IB 1
Figure 7. Distribution of Cadmium from Electroplating Waste in Davidson Soil.
83
-------
51
n
ta
S
B.BI
Figure 8. Penetration of Cadmium Leached from Pigment Waste Olirough Davidson Soil.
HB.BBr
PDRE: VDLUHE
Figure 9. Penetration of Cadmium Leached from Water Base Paint Through Davidson Soil.
84
-------
the waste leachate was generally low to
non-detectable except for periodic surges
that probably occurred as the waste compo-
sition changed through leaching. The cad-
mium in the soil effluent was generally
low, remaining near or below the detection
limit but often exceeded the challenge con-
centration.
These results indicate that little
cadmium-ion hazard would result from the
disposal of these last two wastes on David-
son soil. They also indicate that the or-
ganic fraction may play an important role
in reducing the migration attenuation po-
tential of the soil, an effect that should
be examined further.
CONCLUSIONS
Various industrial wastes contain
hazardous metallic ions. However, speci-
fic metals leach differently from the
wastes depending upon the type of salt or
complex in which the metal exists. The
composition of the leachate and its solu-
bilizing and exchange characteristics de-
termines how a specific metal migrates
through a given soil. Metals previously
absorbed on the soil may also be flushed
off by a change in the leachate. Compo-
nents in highly soluble wastes can rapidly
exceed the absorption and/or exchange capa-
city of the soil and cause a serious water
hazard, but sparingly soluble wastes usual-
ly present less of a hazard. This work em-
phasizes the need to ascertain the poten-
tial of specific metals to migrate through
various soils when carried by leachates
having different compositions.
(4) N.E. Korte, J.M. skopp, E.E. Niebla
and W.H. Fuller, "A Baseline Study On Trace
Metal Elution From Diverse Soil Types",
1975, Water, Air, and Soil Pollution, 5-149-
156.
(5) W.H. Fuller, N.E. Korte, "Attenuation
Mechanism of Pollutants Through Soil", 1976,
In: Gas and Leachate From Landfills: For-
mation, Collection, and Treatment. E.J.
Genetelli and R.E. Landreth (EDS). Joint
Symposium, Cook College, State University
Rutgers and U.S. Environmental Protection
Agency, Mar 23-24 1975, EPA Mar 1976 600/9-
76-004.
(6) Environmental Protection Agency, "In-
terim Primary Drinking Water Standards",
Mar 1975, Federal Register, Part II, Vol.
40, No. 51:11990.
REFERENCES
(1) "Report to Congress, Disposal of
Hazardous Wastes'1, 1974, Superintendent of
Documents, U.S. Government Printing Office,
Washington, D.C. 20402, SW-115.
(2) "Polluted Groundwater; Some Causes,
Effects, Controls, and Monitoring", July
1973, Office of Research and Development,
U.S. Environmental Protection Agency, EPA-
600/4-73-001 B.
(3) "Polluted Groundwateri A Review of
the Significant Literature," Mar 1974,
U.S. Environmental Protection Agency, EPA-
600/4-74-001.
85
-------
FIELD SURVEY OF SOLID WASTE DISPOSAL SITES: A PRELIMINARY REPORT
B. L. Folsom, Jr., J. M. Brannon, and A. J. Green, Jr.
Environmental Effects Laboratory
U. S. Army Engineer Waterways Experiment Station
P. 0. Box 631
Vicksburg, Mississippi 39180
ABSTRACT
The vertical migration of chloride (Cl), total organic carbon (TOC), chromium (Cr),
copper (Cu), and cadmium (Cd) in the soil below a sanitary landfill was investigated.
Soil samples were taken at the municipal waste-soil interface, at groundwater, and at
several intermediate depths. Soil samples were extracted with both distilled-deionized
water and hot 8JI HNO^. Results indicated that the soluble species, as represented by Cl,
had migrated completely through the profile. The data indicated that the refuse in the
landfill was exerting a significant influence on the migration of Cr, Cu, and Cd through
the soil. The formation of unknown complexes of Cd, Cr, and Cu with constituents con-
tained in the leachate from municipal refuse resulted in their migrating deeper into the
soil profile when compared to soil in the natural state.
INTRODUCTION
The ultimate recipient of many types
of municipal and industrial solid waste is
the land. Within the disposal site biolog-
ical, chemical, and physical processes may
act on these solid wastes to release con-
taminants from them to the air or water.
Conversely, under proper conditions, chemi-
cal, biochemical, and physical processes
may serve to reduce contaminant concentra-
tions or chemically alter contaminant tox-
icity, reducing their potential threat to
the environment. This paper is a prelimi-
nary report of potential pollution of the
groundwater and vertical migration of sev-
eral selected constituents at a sanitary
landfill located in the upper midwest.
METHODS AND MATERIALS
Site Description
The site was given the designation
number 01. Site number 01 was first opened
in 1947 as an open dump and later changed
to a sanitary landfill. The trench method
of filling was adopted in 1950 and operated
as such until the site was closed in 1960.
The refuse placed into the sanitary landfill
was not compacted but was covered with a
16-inch layer of soil. A total of 28
trenches were eventually filled. Trench
positions at site 01 are illustrated in
Figure 1.
• ai
Figure 1. Municipal refuse disposal site
and boring location at site 01.
Three boring/sample locations were
positioned in the landfill and five out-
side the landfill. The three borings in
86
-------
the landfill were designated Bl, B2, and
B3. Two borings designated B6 and B7A were
located on the anticipated "updip" side of
the hydraulic gradient. Three borings were
also located on the anticipated "downdip"
side of the hydraulic gradient and were
given the designations B4, B5, and B8. The
borings located in the landfill were placed
in trenches that were filled in 1951 (Bl),
1957 (B3), and 1960 (B2). The boring loca-
tions are also illustrated in Figure 1.
Soil Sampling Procedures
Soil samples were taken at the
landfill-soil interface, immediately above
the water table, and at several intermedi-
ate depths. It should be noted that sam-
ples for the control borings were taken at
elevations corresponding to the elevations
of samples taken under the landfill. The
borings were made with a truck-mounted
rotary drill using a hollow core 6-5/8-
inch-O.D. flight auger. Soil samples were
obtained by first drilling the hole with
the flight auger to a depth slightly above
that where the sample was to be taken. The
internal drill rod was removed and either a
3-inch Hvorslev fixed-piston sampler fitted
with a 3-inch-O.D. Shelby tube or a 1-3/8-
inch split-spoon sampler lowered through
the inside of the auger and pushed into the
soil to obtain the sample. The Hvorslev
sampler was used to obtain undisturbed soil
samples and is illustrated in Figure 2.
The split-spoon sampler was used when the
soil would not remain in place in the
Hvorslev sampler. A portion of the undis-
turbed soil samples was taken for chemical
analysis and placed into airtight, acid-
washed polyethylene jars. The jars were
immediately packed in ice until time of
analysis. A bailed sample of the ground-
water from each boring was taken after the
last soil sample was obtained, placed into
airtight polyethylene jars, and immediately
packed in ice until time of analysis.
The waste composing the landfill from
each of the three trenches was sampled at
7 feet and at 20 feet, corresponding to the
upper half of refuse thickness and at the
soil-waste interface, respectively.
Following the completion of sampling,
soil, groundwater, and waste samples were
repacked in ice and shipped to the labora-
tory by air freight.
Figure 2. Hvorslev fixed-piston sampler
and sampling procedure.
Preparation for Chemical Analysis
Upon arrival at the laboratory, the
samples were placed in a 4°C cold room
until time of extraction and subsequent
chemical analysis. The time interval be-
tween sample acquisition and extraction-
analysis was two weeks. The groundwater
samples were centrifuged at 2200 rpm for
30 minutes. The supernate was then fil-
tered through 0.45-pm millipore filters
and preserved for chemical analysis as
outlined in Table 1. Preservation methods
and constituents to be analyzed are given
in Table 1.
TABLE 1. PRESERVATION OF GROUNDWATER
FILTRATES AND WATER EXTRACTS FOR CHEMICAL
ANALYSIS
Preservative
None
None
HN03
HC1
NaOH
Chemical
N0?
TOC
+ KMnOA (pH 1)
(pH 1)
(pH 11)
Hg
Mg
Cd
Pb
CN
y
5
y
species
, SOv 11,
Ca
Cr
Zn
y
y
9
Na
Cu
B,
N03,
, As, Be,
, Mn, Ni,
Se
87
-------
Water Extract
Two hundred grams of wet soil were
weighed into 1000-ml polycarbonate centri-
fuge bottles, 800 ml distilled-deionized
water added, the bottles sealed, and then
shaken on a rotary shaker for 1 hour. Per-
cent moisture was determined on a separate
subsample of wet soil. After shaking, the
bottles were centrifuged at 2200 rpm for 30
minutes and the supernate filtered through
0.45-ym millipore filters. The resulting
extracts were preserved as outlined in
Table 1 for chemical analysis. Results
are reported as micrograms of constituent
per gram of oven-dry soil.
HN03 Extract
Fifty grams of wet soil were weighed
into 250-ml teflon beakers and 60 ml of
81J HN03 added. The soil-acid suspensions
were heated to 95°C for 45 minutes and
stirred every 15 minutes. After cooling
to room temperature, the suspensions were
quantitatively transferred and filtered
with 8N HN03 through 0.45-ym millipore
filters. The digested soil was washed
three times with 20-ml portions of 8N_ HN03.
The filtrate was quantitatively transferred
with 811 HN03 to 250-ml volumetric flasks
and made to volume, again using 8N^ HNC>3.
The following elements were determined on
the acid extracts: As, Be, Cd, Cr, Cu, Mn,
Ni, Pb, Se, Zn, and B. Results are re-
,ported as micrograms of metal per gram of
oven-dry soil (percent moisture was ob-
tained from the distilled-deionized water
analysis).
Chemical Analysis
Chemical analysis of the groundwater
filtrates and water extracts listed in
Table 1 was accomplished using the proce-
dures and instrumentation as given in
Table 2. It should be noted that the HN03
extracts were analyzed for only 11 of the
22 constituents indicated in Table 2.
This paper is a preliminary report for
evaluation of a municipal sanitary landfill
site concerning the pollution potential and
vertical migration of contaminants; there-
fore, only five of the chemical contami-
nants outlined in Table 1 and Table 2 have
been examined.
TABLE 2. PROCEDURES AND INSTRUMENTATION
USED TO CHEMICALLY ANALYZE THE GROUNDWATER
FILTRATES AND WATER EXTRACTS OBTAINED FROM
SITE 01
Chemical species
Procedures and/or
instrumentation
S04
SO,
Cl
TOC
Hg
+Mg, Ca, Na, As,
Be, Cd, Cr, Cu,
Mn, Ni, Pb, Zn,
B, Se
CN
Standard Turbidimetric
Method* in combination
with a Varian Model No.
635 UV-VIS Spectropho-
tometer
Standard Potassium
lodite - lodate Titra-
tion Procedure
Standard Mercuric
Nitrate Titration
Method*
Technicon II AutoAnaly-
zer, Industrial Method
No. 100-70W**
Determined on an Envir-
otech Model No. DC 50
TOC Analyzer
Determined on a Nissei-
sangyo Zieman Shift
Atomic Absorption
Spectrophotometer
Determined on an
Argon Plasma Emission
Spectrophotometer,
Spectrametrics, Inc.,
Model No. II
Technicon II AutoAnaly-
zer, Industrial Method
No. 315-74W**
* Standard Methods for the Examination of
Water and Wastewater, American Public
Health Association, New York, Ed. 13,
1971.
** Technicon Industrial Systems, Terrytown,
New York.
+ Only these metals were analyzed for in
the HNO_ extracts.
-------
RESULTS AND DISCUSSION
Physical Analysis
Bulk density values ranged from 1.506
to 1.778 g/cc, averaging 1.645 g/cc. Water
content values ranged from 2.4 to 7.5 per-
cent and averaged 3.6 percent. Permeabil-
ity of the soils ranged from 2.0 x 10~^ to
1.4 x lO"1 cm/sec with an average value of
0.91 x 10" 1 cm/sec. The soil was classi-
fied as a sand to gravelly sand throughout
the profile.
From the results of the physical data
presented above, it can be concluded that
the soil under the municipal landfill site
01 was extremely porous and should have
little water-retention capacity. It should
be expected, therefore, that given a high
annual rainfall (50 inches per year) and
the extreme porosity of the soil, leaching
of contaminants from the municipal waste
into the lower depths of the soil profile
could occur.
Chemical Analysis
The curves in Figures 3 through 10
have been calculated in the following
manner. The data points for the control
curves represent the mean values of the
chemical species obtained for boring 6 and
boring 7A. The data points for the waste
curves are the mean values of the chemical
species obtained from borings 1, 2, and 3
taken directly under the landfill. Borings
6 and 7A were outside the landfill site,
"updip" from the hydraulic gradient, and
are therefore considered to represent con-
trol or background borings. The actual
curves were calculated and plotted by
fitting in a least squares sense the
equation:
9 3
y = a + bx + cxz + dxj
It should be pointed out that the r^
values indicated on Figures 3-10 are not
coefficients of determination but merely
a goodness of fit of the data points to
the third-order polynomial indicated above.
Chloride
The water extractable chloride (Cl) in
micrograms of Cl per gram of soil was
plotted against depth below the municipal
waste-soil interface (Figure 3). Prelimi-
nary examination of the data indicated that
CHLORIDE CONCENTRATION,
WATER EXTRACT
10 20
uj 30 -
' ' T
(
"
CONTROL -^
r* =0.99
_ \
\
<
x«- WASTE
I-* ' = 0.89
V
Figure 3. Chloride concentration in the
soil under the waste and control
borings as determined in water extracts.
Cl would be representative of the behavior
of the water soluble chemical species con-
sidered in this study. As illustrated in
Figure 3, Cl concentration was fairly con-
stant with depth below the landfill and
also below the control borings. The water
extractable Cl concentration was near 20
yg/g from the municipal waste-soil inter-
face through the soil column to a depth of
50 feet for both the waste and control. A
slight increase, 2-5 Pg/g, occurred below
a depth of 50 feet below the landfill.
Statistical analysis revealed no signifi-
cant difference between the two curves.
Chloride concentration in the groundwater
was 5 yg/ml under both the landfill and
the controls, indicating dilution had al-
ready occurred. The behavior of Cl, rep-
resenting the soluble species, woi'la indi-
cate that after 15 years, most of the
soluble species have been leached and have
migrated from the upper depths of soil and
from municipal waste through the soil into
the groundwater. Due to the high soil
permeability under site 01 and the high
average rainfall, the leaching of the
soluble species from the waste through the
soil profile would be expected to occur.
89
-------
Total Organic Carbon
The data in Figure 4 indicated that
water extractable total organic carbon
concentration (TOC) in the soil under the
landfill was higher than that in the soil
TOTAL ORGANIC CARBON, (ig/g
WATER EXTRACT
0 10 20 30 40
organic carbon through the soil column had
occurred and had reached the groundwater
under the landfill at site 01.
Chromium
Chromium (Cr) concentration in the
nitric acid extract versus depth below the
municipal waste-soil interface is shown in
Figure 5. The data indicate that Cr be-
havior was different under the landfill
CHROMIUM CONCENTRATION, (ig/g
HNO3 EXTRACT
Figure 4. Total organic carbon in water
extracts of soil under waste and con-
trol borings at site 01.
(
0
1-
"•„ 10
UJ
*
d
UJ
"~ 20
6
u 30
<
$
<40
O
1
o
Ld
m
i
h- 60
Q.
U
Q
> 1 23456
• i • i • T-n» ' i i i i i
"\ x
\
\ •
1
WASTE ^^ /
r*=0.79 ,
/
7 V
/ /
/ /**- CONTROL
y r*=o.oa
/]
/.L
- / 1
- / /
- \ /
- -\r
in the control borings. The TOC concen-
tration at the municipal waste-soil
interface was near 35 yg/g and indicated
that TOC was still leaching from the waste
some 15 years after the landfill had been
closed. The shape of the TOC curve under
the landfill (Figure 4) indicated that
vertical migration of organic carbon had
occurred. The concentration of TOC in the
control borings from about 30 to near 60
feet below the landfill indicated that ac-
cumulation of organic carbon had occurred
in the soil. The vertical migration of TOC
under the landfill was further evidenced by
the increased levels of TOC in the ground-
water under the landfill versus the con-
trols. The groundwater under the landfill
had a higher TOC level, 39.7 yg/g, than
that under the control, 23.5 yg/g. The
data indicated that vertical migration of
Figure 5. Chromium concentration in HNO-j
extracts of soil at site 01 under the
waste and control borings.
when compared to Cr concentration in the
control. The Cr concentration under the
landfill remained fairly constant with
depth, ranging from near 3 yg/g at the
interface to slightly less than 2 yg/g
immediately above the groundwater.
Chromium concentration in the HNOo extracts
of the control borings showed quite dif-
ferent behavior. Initial concentration
was near 3 yg/g at the interface, in-
creased to 5 yg/g at 15 feet, then de-
creased to 1-2 yg/g immediately above
the groundwater. The different behavior
of Cr in the HN03 extracts under the land-
fill and control borings indicated that
90
-------
vertical migration of Cr had occurred under
the landfill. Evidently, some chemical
component(s) leaching from the landfill
was mobilizing soil Cr, resulting in de-
creased Cr in the soil under the landfill.
Chromium concentration in the water
extracts versus depth below the municipal
waste-soil interface is illustrated in
Figure 6. The data indicated that there
CHROMIUM CONCENTRATION, (ig/g
WATER EXTRACT
0
0
H
uT
o
U.
E
Z 2°
-J
O
(0
u 3O
1-
w
I
< 40
0.
MUNICI
s 50
J
I
1- 60
0.
70
01 0.2 0
.
t
CONTROL -+A
r-2 = QSP 1
r t
~
_
; 1
—
™ i i
AT- *f<457-£
ft = 0 ff
\
Figure 6. Chromium concentration in water
extracts of soil at site 01 under the
waste and control borings.
was virtually no difference in Cr concen-
tration between the waste and control
borings and that Cr concentration was
constant (0.1 yg/g) throughout the soil
profile from the interface to the ground-
water. Solubility and movement of Cr from
the soil beneath the waste apparently had
already occurred. The data also indicated
that either Cr had not reached the ground-
water or that dilution had already occurred
as there was no difference in concentration
(0.025 yg/ml) between the waste and
controls.
By comparing the data obtained in the
water extract with those obtained in the
acid extract, it is apparent that the water
soluble Cr fraction was very low and fairly
constant. Since the nitric acid extracts
Cr from the organic fraction and part of
the mineral fraction, apparently the verti-
cal migration of Cr in the soil beneath the
landfill had been affected by constituents
contained in leachate from the municipal
waste. As the leachates migrate vertically
through the soil, they may form organic com-
plexes with Cr which are soluble and to-
gether they migrate downward through the
soil. Vertical migration of Cr proceeds
until a point is reached such that the
solubility of the proposed complexes is
reduced resulting in attenuation.
The behavior of copper (Cu) in the
nitric acid extract under the landfill
(Figure 7) is similar to that of Cr in
the nitric acid extract. In fact, the
COPPER CONCENTRATION, (ig/g
HNO3 EXTRACT
24 6 8 10 12
Figure 7. Copper concentration under the
waste and control borings in HNOg ex-
tracts of soil at site 01.
shape of the curves is almost identical.
Again contamination of the groundwater by
Cu was not indicated as the concentration
of Cu was the same, 0.020 yg/ml, for both
the control and the waste borings. This
would seem to indicate that the same
factors controlling vertical migration
91
-------
and attenuation of Cr are also applicable
to Cu. The same reasoning would hold true
for Cu in the water extracts (Figure 8).
COPPER CONCENTRATION,
WATER EXTRACT
0 01 0.2 0.3 0.4
-i—f—i r—
WASTE
=0.58
CONTROL
r* =0.99
05
—I
Figure 8. Copper concentration under the
waste and control borings in water ex-
tracts of soil at site 01.
Cadmium
The vertical migration and attenuation
of cadmium (Cd) in the soil beneath the
landfill and control borings were somewhat
different than the migration and attenua-
tion of Cr and Cu and are illustrated in
Figure 9 for the nitric acid extract and
Figure 10 for the water extract. The con-
centration of Cd under the landfill was
higher than that of the controls in both
the acid and water extracts and was near
0.3 yg/g for both cases. The data in
Figure 9 indicated that Cd concentration
was somewhat higher under the landfill than
under the control. The concentration of Cd
in the water extract was very nearly equal
to that in the nitric acid extract, espe-
cially under the landfill. The Cd concen-
tration in the groundwater under the land-
fill was 0.05 yg/ml (mg/&), while that
under the control was 0.02 yg/ml. From
the data presented for Cd, it can be con-
cluded that the vertical migration of Cd
CADMIUM CONCENTRATION,
HN03 EXTRACT
O.I O.2 O.3 0.4 ttS
Figure 9. Cadmium concentration in
extracts of soil at site 01 under the
waste and control borings.
CADMIUM CONCENTRATION, (ig/g
WATER EXTRACT
01 02 03 O4
0.5
Figure 10. Cadmium concentration in water
extracts of soil at site 01 under the
waste and control borings.
92
-------
through the soil profile is not affected
by the leachate from the municipal waste
to the extent that Cr and Cu are affected.
Apparently, the proposed formation of Cd
complexes with constituents contained in
the leachate from the municipal refuse is
more stable than the complexes of Cr and
Cu. Assuming this to be true, one would
expect Cd to migrate further down through
the soil profile than either Cr or Cu.
Since it has been proposed that the
mobility of Cr, Cu, and Cd was affected by
some constituent(s) originating from munic-
ipal refuse, a regression analysis of TOC
on the above metals was performed. Results
of the regression analysis revealed, how-
ever, that little or no relationship
existed between TOC and Cr, Cu, or Cd in
either water or acid extracts. A possible
explanation for the absence of a relation-
ship between TOC and the metals is that the
proposed organic complexes of Cr, Cu, and
Cd are present in fraction(s) extracted in
the acid digest (i.e. not water soluble).
Since TOC was not determined on the acid
extracts, little or no relationship between
TOC in the water extracts and Cr, Cu, and
Cd in the acid extracts should be expected.
CONCLUSIONS
From the results presented in this
preliminary investigation of site 01, a
municipal sanitary landfill, it appears
that vertical migration and resultant con-
tamination of groundwater occurred for the
soluble chemical species as represented by
the data presented for Cl. Vertical migra-
tion and resultant contamination by TOC and
Cd originating from the landfill did occur.
Vertical migration and groundwater contami-
nation of Cr and Cu originating from the
landfill did not occur.
The mobility and attenuation of Cr,
Cu, and Cd are apparently affected by un-
known constituents contained in the leachate
from municipal refuse.
93
-------
FIELD VERIFICATION OF HAZARDOUS INDUSTRIAL WASTE
MIGRATION FROM LAND DISPOSAL SITES
by J. P. Gibb
Illinois State Water Survey
Box 232, Urbana, Illinois 61801
ABSTRACT
Development of effective investigative and monitoring techniques for detecting and
quantitatively evaluating the extent of groundwater pollution from surficial toxic waste
disposal sites in humid regions is the primary purpose of this study. It is also designed
to verify in the field the effectiveness of soils and surface deposits in a glaciated
region to retain specific hazardous chemicals. Three study sites were selected on the
basis of geology, types and quantities of hazardous wastes, and manner of waste disposal.
These sites are underlain by low-permeability silts and clays that should be efficient in
retaining the toxic wastes and minimizing groundwater pollution. An extensive drilling
program to obtain uncoiisolidated sediment cores and groundwater samples for chemical
analyses has been undertaken at each site. This paper describes methodologies used and
preliminary results at one of the three sites. Work to date shows that soil coring is an
effective tool for mapping the migration patterns of chemical pollutants through the earth
materials. This approach also provides field data to verify the effectiveness of various
soil types to adsorb or retain different chemical pollutants.
INTRODUCTION
In Illinois, 62 land disposal sites are
permitted by the State Environmental Pro-
tection Agency to receive hazardous chemical
wastes. In addition, more than 1000 active
or abandoned landfill sites and several
hundred private industrial disposal sites
have received large but unknown quantities
of all types of wastes including toxic chem-
icals. Many of these are adjacent to or di-
rectly underlain by shallow aquifer systems
vulnerable to pollution from surficial
sources.
The amount and areal extent of hazard-
ous material migration from these disposal
sites in Illinois is not known. Few sites
are monitored for possible pollution of con-
tiguous aquifers and those that are monitored
appear to be ineffectively instrumented. Tra-
ditionally, monitoring wells are installed
and water samples collected and analyzed per-
iodically. However, these wells generally
cannot monitor very large vertical segments
of an aquifer, and the water samples are not
always analyzed for the many different organ-
ic or inorganic chemical compounds that may
originate from the disposal sites.
Existing air and surface-water pollu-
tion regulations are forcing an ever-in-
creasing volume of hazardous chemical waste
to the land for ultimate disposal. This is
true particularly in the heavily populated
and industrialized regions of the United
States where most of these wastes are gen-
erated, used, and eventually discarded. In
the humid parts of the country, shallow
groundwater reservoirs are recharged by
precipitation infiltrating through the land
surface. As a result, many shallow aqui-
fers may be in danger of serious water
quality degradation if soils are not ef-
fective in keeping hazardous wastes from
migrating downward to the aquifers. Knowl-
edge of groundwater pollution occurrences
from such sources is steadily increasing.
These occurrences indicate that a serious
threat to public health may exist until all
surface and underground toxic chemical dis-
posal sites are located, any migration or
-------
groundwater pollution evaluated, and correc-
tive measures applied where necessary.
Purpose of Study
The primary purpose of this study is
to develop effective investigative and moni-
toring techniques for detecting and evalu-
ating quantitatively the extent of ground-
water pollution from surface toxic waste
disposal sites. The study also is designed
to verify in the field the effectiveness of
glaciated region soils and associated sur-
face deposits in retaining specific hazard-
ous chemicals.
The findings of this study should pro-
vide an invaluable tool for predicting pos-
sible long-term effects of hazardous chemi-
cal disposal on land. Also, the methodol-
ogies used should be immediately applicable
in evaluating the extent of hazardous chem-
icals migration from disposal sites situ-
ated in similar geohydrologic environments
throughout Illinois and much of the other
15 glaciated, humid-region states in the
country.
SITE SELECTION
Three sites were selected for study on
the basis of geology, the types and quanti-
ties of hazardous wastes generated, and the
manner of waste disposal. Sites were se-
lected where the unconsolidated materials
range from about 15 to 75 feet thick and
consist predominantly of low-permeability
silt and clay soils. Pennsylvanian age
shales or sandstones also lie beneath the
glacial deposits at all three sites. Thus,
from the geology, these sites would theo-
retically be desirable disposal areas with
little resulting groundwater pollution.
Two sites (A and B) are secondary zinc
smelting plants located in south-central
Illinois. A large quantity of waste from
these plants has been disposed of in solid
form on the plant property over several
years of operation. The other site (C) is
a chlorinated hydrocarbon processing plant
located in east-central Illinois. Approxi-
mately half of the liquid waste from this
plant is stored and pretreated in lagoons
or pits on the plant property and then in-
jected into a deep disposal well. The pos-
sible effects of the surface lagooning and
storage pits are the principal concern in
this study. This discussion will be limit-
ed to work accomplished at Site A.
Site A
Site A is a secondary zinc smelter lo-
cated in south-central Illinois. The plant,
which started operations between 1885 and
1890, initially processed zinc ore. It was
converted to a secondary zinc smelting fa-
cility about 1915. Wastes from the smelt-
ing operations during the first 85 years
were principally heavy metals-rich cinders,
and ashes. During the early years large
quantities of cinders were used as road fill
or surfacing for secondary roads and farm
lanes in the plant area. The remainder was
used as fill material around the plant
buildings and as surfacing over the proper-
ty. As a result of these disposal prac-
tices, there now is a 1- to 10-foot thick
layer of metals-rich cinders covering about
12 acres of the plant property.
In compliance with air pollution con-
trol regulations, a scrubber was installed
on the plant stack in 1970. Prior to that
time, wind-blown ash, rich in zinc and other
heavy metals, was deposited on the plant
site and on approximately 100 acres of sur-
rounding farmland. This source of pollution
has now been minimized, but wastewater from
the scrubber (about 14,500 gallons per day)
is deposited in a seepage pit constructed
on the cinder materials that form the land
surface at the site. Several hundred tons
of high zinc content sludge have accumulated
from the frequent cleaning of this pit and
are now being reprocessed for zinc and lead
recovery. Most of the water from the pit
infiltrates into the ground underlying the
plant property.
Prior to the study, limited data sug-
gested that groundwater pollution might be
occurring from three possible sources:
1) the large volume of solid waste material
(cinders and stored junk to be processed)
at the plant site; 2) highly mineralized
liquid wastes from the stack scrubbers; and
3) wind-blown ash from the smelter furnaces
prior to installation of the scrubbers.
Because of the long period of operation
of this facility and the various sources and
forms of pollution likely to be present,
this site appeared to be most desirable to
study in detail. The decision was made to
devote maximum time, effort, and money at
this site to develop the study methodology
and optimize its application to other sites.
95
-------
METHOD OF INVESTIGATION
An extensive drilling program to obtain
unconsolidated sediment cores and groundwa-
ter samples has been undertaken at each
site. Chemical analyses of the core and
groundwater samples are being used to de-
fine: 1) the vertical and horizontal migra-
tion patterns of chemical pollutants through
the shallow glacial deposits and aquifer
profiles; 2) the seasonal variation of toxic
chemical levels in groundwater near these
sites; and 3) the residual toxic chemical
buildup in the unconsolidated materials in
the vicinity of the sites.
Continuous vertical core samples for
geologic study and chemical analyses have
been obtained with conventional Shelby tube
and split spoon sampling methods through
hollow stem augers. These dry drilling
techniques were used to minimize chemical
alteration of samples from drilling fluids
or external water during excavation.
Coring has been done with a truck-
mounted Central Mining Equipment (CME) 55
and a CME 750 rig mounted on an all-terrain
vehicle. The drilling crew consisted of an
equipment operator and helper, assisted if
necessary by the principal investigators.
For the first few test holes drilled at each
site, a geologist from the State Geological
Survey assisted in collecting samples and
made preliminary soil identifications for
use in subsequent testing.
Shelby tube and split spoon samples
were extruded in the field as collected, cut
into 6-inch lengths, placed in properly la-
beled wide mouth glass jars, and delivered
to the State Geological Survey and Environ-
mental Analytical Research Laboratory at the
University of Illinois for processing and
analyses. One 6-inch length of core from
each 5-foot segment and/or change in forma-
tion was taken by the drilling contractor
for moisture content determinations before
being sent for geological and chemical
analyses.
Core Analysis
Core samples for heavy metals determin-
ations are being analyzed at the Environ-
mental Analytical Research Laboratory with
zinc as a target element. Previous experi-
ence in determining heavy metal contaminants
in soil showed that digestion of a dried
soil sample in 3_N HC1 at slightly elevated
temperatures effectively releases the heavy
metals without destructing the silicate lat-
tice of the soil. The heavy metals so re-
leased are determined by atomic absorption
spectroscopy, the principal methodology
used to date.
For a limited number of soil samples,
the multi-element capability of optical
emission spectroscopy has been used to de-
termine the Cd, Cu, Pb, and Zn concentra-
tions. Now, instrumentation and methods
are being developed for use of nondisper-
sive X-ray emission spectroscopy to permit
semi-automated multi-element analysis for a
larger number of elements with greater ef-
ficiency than is possible with current
methods.
Preliminary tests using atomic absorp-
tion measurement of small spot samples in-
dicate that the 6-inch long samples are too
heterogeneous to permit reproducible anal-
ysis. Reproducible results have been at-
tained by homogenizing the samples and sub-
dividing them to sample weight levels of 1
gram for atomic absorption and 50 milli-
grams for emission spectroscopy. Pelletized
samples of approximately 2 grams have been
prepared for X-ray emission spectroscopy.
Well Construction
Analyses of water samples from observa-
tion wells has been the traditional method
for monitoring groundwater pollution. To
demonstrate the effectiveness of such an
approach and the relative cost of using
wells as compared to coring, a number of
small-diameter (2-inch) observation wells
were constructed. At Site A, where heavy
metal contaminants were expected, plastic
casing, screen, and pumping equipment were
used.
Observation wells at Site A were con-
structed in the following manner. A 7-inch
diameter hole was constructed and a 2-inch
diameter PVC pipe (bottom 2 feet slotted
with a hacksaw) was placed in the hole.
Gravel was placed from the bottom of the
hole to a level about 1 foot above the slot-
ted portion of the pipe followed by about
6 inches of sand. The remainder of the an-
nulus was filled with bentonite slurry to
land surface (see Figure 1). A shallow
well (10-15 feet deep) was constructed at
each location (see Figure 2) and deeper
96
-------
1/2" discharge
pipe
airline
7" bore hole -*-
slotted PVC
well casing
3"
x,
— \
x -
°n°o
°0°
o o
o o
00
o o
T
-vj
_
~
—
^
=
=
~
=
'^•
n
= ^
_^l
^^=
==
.-_
^mi
_^_
S
x ^\
/ ' ^
^
s
0 o°
° o o
O o
o
U"n
o 0
0%
°0
0°0
6" sand
gravel
Figure 1. Typical well and pumping
mechanism.
wells just above the bedrock were added at
nine locations.
Observation wells are equipped with in-
dividual pumping devices to minimize possi-
ble contamination of well samples from other
wells. The pumping device consists of a
1/2-inch diameter PVC discharge pipe that
extends from above the 2-inch well casing
to the bottom of the well. A tee fitted
with short nipples and removable caps is
placed at the top of this pipe (Figure 1).
The cap on the vertical segment can be re-
moved to allow for water level measurements
within the 1/2-inch pipe. The cap on the
horizontal segment (water discharge outlet)
is vented to permit stabilization of the
water level within this pipe.
A 1/4-inch plastic airline also is in-
stalled in each well. The airline is at-
tached to a Shrader valve at the top of the
well casing and extends the entire depth of
the well. The lower end of the airline is
bent up into the bottom of the 1/2-inch dis-
charge pipe for a distance of about 3 inches.
Water is pumped from the wells by re-
moving the cap from the horizontal portion
of the 1/2-inch pipe and applying air to
the system through the Shrader valve.
Pumping from depths as great as 70 feet is
possible with only a bicycle-type hand
pump. A gasoline powered 4-cylinder air-
compressor capable of delivering about 5
cubic feet per minute at pressures up to
60 psi is being used. An activated char-
coal filter has been placed in the dis-
charge line from the compressor to insure
that air from the compressor is not intro-
ducing airborne contaminants.
Water Sample Analysis
Water level measurements are made and
water samples collected from each well once
a month. Samples are collected in 6-ounce
plastic containers and placed on ice until
they can be refrigerated in the laboratory.
Each well is pumped for a period adequate
to insure that all stored water in the well
casing has been removed. The wells are al-
lowed to recover and a sample is then col-
lected from the water that has just en-
tered the well. This procedure insures
that the water sample collected is repre-
sentative of the water flowing through the
aquifer at the time of collection.
Heavy metals are determined by atomic
absorption spectroscopy with appropriate
correction for blank and background absorp-
tion. Concentrations of Zn, Pb, or Cu be-
low the detection limit of atomic absorp-
tion spectroscopy are determined by anodic
stripping voltammetry.
Secondary Methods
A number of qualitative methods of
groundwater pollution detection and mapping
have been used with varying degrees of suc-
cess. In an effort to evaluate the relative
effectiveness of a few of these methods,
electrical earth resistivity surveys, soil
temperature surveys, soil and vegetation
mapping, and color-thermal infrared and
normal color photography have been employed
at Site A.
RESULTS
To date, 47 wells at 34 locations have
been completed at Site A. Cores were taken
at each well and at 19 additional sites
(Figure 2). Total well and core sampling
97
-------
O CORE HOLE
• WELL
SCALE OF FEET
0 100 200 300
b
NORTH
Figure 2. Location map of central portion of Site A.
footages are about 1300 and 1275 feet
respectively.
The glacial materials at this site are
about 60 to 75 feet thick. The strati-
graphic units recognized are essentially un-
iform in character and thickness and gen-
erally flat. The elevation of the surface
of the Pennsylvanian bedrock dips from 447
feet above sea level on the east to about
432 feet on the west. A brief description
of the units, from top down, follows:
A) Peoria Loess (4-6') Brownish
gray clayey silt, noncalcareous,
with iron stains.
B) Roxana Silt (3-4') Dark brown
clayey silt with up to 34% sand
(av. 20%), noncalcareous.
Glasford Formation
C) Berry Clay Member (3-4') Dark
gray sandy silty clay with trace
gravel, up to 40% sand, noncal-
careous (an accretion gley).
D,E) Vandalia Till Member (2-8')
Yellowish brown, oxidized in up-
per portion, little yellowish
gray at base, sandy silt, slight-
ly gravelly, calcareous; thin
silty sand (D) at top (1/2-1 1/2')
appears continuous across area;
upper 14-18' of till below, al-
though less sandy, may be part of
Vandalia.
F) Smithboro Till Member (25-31')
Dark gray sandy silt till, with
little gravel, contains discon-
tinuous lenses of silt, sand and
dark olive brown, leached silty
clay, probably sheared into the
Smithboro from the Lierle Clay
below, generally tough, compact,
generally calcareous but carbon-
ate content less in lower 18'.
This unit may be divided into an
upper and lower zone separated
by a silt bed. No conclusion has
yet been drawn concerning the re-
lationship of units E and F.
98
-------
Figure 3. Water table contour map, Site A (November 1975),
G) Lierle Clay Member (1-2') Dark
olive brown sandy silty clay,
with little gravel, noncalcare-
ous, soft.
Banner Formation
H) Unnamed Till Member (1-2') Gray
clayey silty till, sandy, with
some gravel, mottled yellowish
brown, brown and gray in upper
part, strongly calcareous, hard,
dry, a few scattered silt and
sand lenses, predominantly dry.
Bond Formation (Pennsylvanian bed-
rock) - Greenish gray shale with
abundant m-i ca: *> ard, drv.
The stratigraphic units and the textur-
al mineralogical data are shown in Table 1.
The expandable clay minerals, generally
referred to as montmorillonite (M), make up
more than 80% of the clay minerals within
the Peoria Loess, Roxana Silt, and Berry
Clay Member, thereby suggesting a high base
exchange potential in the upper 13 feet of
the materials encountered. The thin, con-
tinuous silty sand zone at the top of the
Vandalia Till would appear to be the only
'permeable' unit to allow groundwater to
travel laterally at any moderate rate away
from the site. Although there is probably
some downward movement of groundwater through
the remainder of the Glasford Formation, it
would be expected to be extremely slow.
Water level measurements taken in the
shallow wells were used to construct month-
ly water table contour maps for the site.
These wells are from 10 to 15 feet below
land surface and are all finished in the
sandy unit (D) at the top of the Vandalia
Till Member. Data collected to date show
no significant change in the shallow water
levels at this site. The principal ground-
water flow paths from the plant site are
illustrated in Figure 3. Water from the
eastern half of the plant, including the
liquid disposal pond, appears to be moving
east-southeast; water from the western half
of the plant site seems to be moving west-
southwest. Therefore, any pollutants in
99.
-------
510
500
490
480
470
460
450
440
LAND SURFACE'
SHALLOW WELL
7
DEEP WELL
APR MAY JUN JUL AUG SEP OCT NOV
1975
Figure 4. Water level elevations.
TABLE 1. TEXTURAL AND MINERALOGICAL DATA
Thick-
ness % % % % M Total
Units
(A)
(B)
(C)
(D)
(E)
(F)
(G)
(H)
Peoria
Loess
Roxana
Silt
Berry
Clay
Vandalia
Till
Smithboro
Till
Lierle
Clay
Banner
(ft)
4-6
3-4
3-4
.5-1.5
2-8
25-31
1-2
1-2
Sd
3
20
28
51
34
29
21
28
St
58
49
28
31
35
42
40
41
Cl
39
31
44
18
31
29
39
31
in Cl
86
91
87
38
28
53
71
56
% M
33
28
38
7
9
15
28
17
NORTHEAST
a1
Sd = sand, St silt, Cl = clay,
M = montmorillonite
Figure 5. Soil zinc concentrations.
the shallow groundwater system should be
moving in the same general directions.
No piezometric surface maps have been
prepared for the deeper units at this site.
Measurements in the wells indicate that wa-
ter levels have not stabilized even after
5 to 6 months of nonpumping (Figure 4).
This is due to the low permeability of the
unit (Banner Formation) in which these wells
are finished.
Single element analyses for zinc have
been completed on samples from most of the
core holes at this site. Figure 5 illus-
trates zinc concentrations in the soil along
two vertical cross sections through the
study area. An explanation of the physical
and chemical phenomena controlling the move-
ment of zinc into the soil cannot be made
100
-------
until multi-element chemical analyses and
textural and mineralogical data are avail-
able for all soil samples.
From general observations, it is noted
that the higher zinc concentrations in soil
are limited to the areas directly beneath
the cinder fill covering the plant property.
The deepest vertical penetrations also seem
to lie beneath the areas of thicker cinder
fill and prefill topographic depressions.
Analyses of water samples from the
wells at this site are now in progress. In
general, zinc concentrations of water from
all wells are less than 1 ppm and do not
appear to vary significantly from month to
month. Preliminary data also suggest that
mineral concentrations in the samples sta-
bilize after the second or third month of
sampling.
Complete analysis of all soil and water
samples should provide the needed data to
explain the phenomena controlling the move-
ment of heavy metals from this site.
Preliminary Cost Analysis
As previously stated, it was decided
at the beginning of this project to devote
maximum time, effort, and money at Site A
to gain the needed experience and under-
standing of the methodologies being applied.
Therefore, the total expenditures at this
site are much higher than would be necessary
at other sites of this type. The cost to
study a similar site using a minimum moni-
toring approach would be considerably less.
As of January 1, 1976, approximately
1275 linear feet of piezometer-tube obser-
vation wells at 34 different locations have
been completed at a total cost of about
$6150 ($4.80/foot). Approximately 1300
linear feet of coring has been done for
about $9150 ($7.OS/foot).
As time permits and we gain better un-
derstanding of the monitoring methods be-
ing tested, the cost effectiveness of the
coring technique combined with a minimum
number of wells will be determined. Pre-
liminary data suggest that soil coring is
the more reliable monitoring technique and
definitely should be used to locate the
proper vertical horizons for installing
monitoring wells.
SUMMARY
Work completed at all 3 sites to date
has demonstrated that soil coring is an ef-
fective tool for mapping the migration pat-
terns of chemical pollutants through the
earth materials. This approach also pro-
vides field data to verify the effectiveness
of various soil types to adsorb or retain
different chemical pollutants.
The 3 sites investigated have been in
predominantly dense silt and clay environ-
ments. To determine the general applica-
bility of the coring technique to other
types of environments, it is planned to
conduct an abbreviated pilot study at a
zinc smelter located in a sandy river bot-
tomland area.
Sufficient comparative data are not
available at this time to determine the
relative usefulness of the supplemental
methods being tested in this study. Tem-
perature surveys, electrical earth resis-
tivity surveys, and vegetation mapping and
sampling may prove to be useful in certain
shallow geologic regimes. Although color
infrared photography is very limited in
detecting groundwater pollution, it is a
useful tool for soil and vegetation mapping
and for detecting surface water pollution.
ACKNOWLEDGMENTS
This study is sponsored by the Solid
and Hazardous Waste Research Division of the
Federal Environmental Protection Agency
(Grant R/803216-01) under the general guid-
ance of Mike Roulier, Project Officer. Spe-
cial thanks are given to Dr. Keros Cart-
wright of the Illinois State Geological
Survey and Dr. Arnold Hartley of the Environ-
mental Research Analytical Laboratory for
their enthusiastic cooperation in this study.
Thanks also are due W. H. Walker, Geraghty
§ Miller, Inc., who conceived and initiated
the project before leaving the Illinois
State Water Survey.
101
-------
EVALUATION OF SELECTED LINERS WHEN EXPOSED TO HAZARDOUS WASTES
H. E. Haxo, Jr.
Matrecon, Inc.
2811 Adeline Street, Oakland, CA 94608
ABSTRACT
Disposal or impoundment of hazardous wastes on land presents the potential of these
wastes, or leachates of the wastes, seeping into the ground and polluting surface and
ground water. The use of impervious barriers to intercept and control this seepage of-
fers a means of reducing and possibly eliminating such pollution. An experimental re-
search project is now underway to assess the relative effectiveness and durability of a
wide variety of liner materials exposed to hazardous wastes. The materials under study
include soils and clays, soil cements, asphaltic concretes and other asphaltic composi-
tions, and a wide range of polymeric membranes. The polymeric materials used in the manu-
facture of these membranes include polyvinyl chloride, chlorinated polyethylene, chloro-
sulfonated polyethylene, ethylene propylene rubber, neoprene, butyl rubber, an elastic-
ized polyolefin, a thermoplastic polyester, and polyurethanes. In this study the liner
materials are being exposed to such hazardous wastes as strong acids, strong bases, oil
refinery tank bottom wastes, lead wastes from gasoline, saturated and unsaturated hydro-
carbon wastes, and a pesticide. The experimental procedure being followed is described
and results of preliminary tests used in the selection of materials for extensive testing
are presented.
INTRODUCTION
Our highly industrialized society pro-
duces a great range of nonradioactive in-
dustrial hazardous and toxic wastes in the
manufacture of materials and products. The
need for improving the methods of handling,
storing, and disposing of these wastes is
becoming more apparent (1-4). In passing
the Resource Recovery Act of 1970, Congress
perceived the hazardous waste storage and
disposal to be a problem of national con-
cern (1). They mandated the Department of
Health, Education and Welfare, later the
Environmental Protection Agency, to prepare
a comprehensive report and plan regarding
the storage and disposal of hazardous waste
including an identification of the hazard-
ous waste streams which should require spec-
ial handling.
In their "Report to Congress on Haz-
ardous Waste Disposal" (1), EPA concluded
that the current management of the nation's
hazardous residues is "generally inadequate"
and that the "public health and welfare are
being unnecessarily threatened by the uncon-
trolled discharge of such waste materials
into the environment". In this report it is
pointed out that approximately 10 million
tons of nonradioactive hazardous wastes are
being generated per year and of these 60%
are organic and 40% inorganic. Of these
wastes 90% occur in liquid or semiliquid
form. Generation of these hazardous wastes
is growing at the rate of 5-10% per year.
Disposal on land is increasing even faster
as a result of air and water pollution con-
trols which deny air and water as disposal
sites and require the converting of such
wastes into solid or semisolid form which
must be disposed of on land. Furthermore,
ocean-dumping is becoming unacceptable for
many wastes. This increased disposal of
hazardous wastes on land requires greater
need to prevent toxic materials from en-
tering and polluting ground water systems.
102
-------
Confining hazardous wastes in pits,
ponds, lagoons, landfills or other storage
areas lined with impermeable barrier ma-
terials is being considered as a means of
storing hazardous wastes, even after treat-
ment to detoxify them. Accordingly, this
project was set up to assess the perform-
ance of various recognized liner materials
when exposed to hazardous wastes, to deter-
mine the state of technology, and to supply
information which would be realistic and
useful in establishing regulatory controls
which the EPA recommended (1) to insure ad-
equate management of the collection, stor-
age, and disposal of hazardous wastes.
This paper is a progress report of the
experimental work now underway on EPA Con-
tract 68-03-2173 to make this assessment of
liner materials. The overall approach is
described, the experimental plan outlined,
and exploratory results which were obtained
in selecting materials for intensive testing
are presented.
BACKGROUND
Potential Impermeable Barriers
A wide range of materials are poten-
tially useful as barriers for impounding
hazardous liquids and sludges (5-9). Many
are currently being used to line ponds, res-
ervoirs, lagoons, and canals for the pur-
pose of reducing or eliminating the loss or
seepage of liquids into the ground. These
liners vary considerably in permeability,
durability, and cost. Selection of a liner
for a given installation depends upon soil
conditions, availability of materials, the
level of performance required, and the de-
sign of the pond. Some of the materials
which have been used as pond liners or im-
permeable barriers, or appear to be good
candidates for such applications, are pre-
sented in Table I.
Compacted soils, clays, soil cements,
and asphaltic materials have found wide use
for lining ponds, etc.; nevertheless, they
have limitations particularly in respect to
their permeability to different fluids.
The synthetic polymeric membranes are
of particular interest because of their low
permeability. However, they can vary con-
siderably in physical and chemical proper-
ties, installation, overall performance,
and costs. In addition, even for a given
polymer, there can be considerable variation
TABLE I. MATERIALS POTENTIALLY USEFUL FOR
LINERS OF PONDS CONTAINING HAZ-
ARDOUS WASTES.
Compacted native fine-grain soils.
Bentonite and other clay sealants.
Asphaltic compositions:
- Asphalt concrete
- Hydraulic asphalt concrete
- Preformed asphalt panels
- Catalytically blown asphalt sprayed on
soil
- Emulsified asphalt sprayed on soil or on
fabric matting
- Soil asphalt
- Asphaltic seals
Portland cement compositions:
- Concrete, with seal coats
- Soil cement, with and without seal coats
Soil sealants:
- Chemical
- Lime
- Penetrating polymeric emulsions and
latexes
Sprayable liquid rubbers:
- Polyurethanes
- Polymeric latexes
Synthetic polymeric membranes - reinforced
and unreinforced:
- Butyl rubber
- Ethylene propylene rubber (EPDM)
- Chlorosulfonated polyethylene (Hypalon)
- Chlorinated polyethylene (CPE)
- Elasticized polyolefin (3110)
- Polybutylene (PB)
- Polychloroprene (Neoprene)
- Polyester elastomers
- Polyethylene (PE)
- Polyvinyl chloride (PVC)
in the liners among different manufacturers
due to compound and design differences.
Factors In Selecting Liners for Specific
Installations
In selecting liner materials for confining
hazardous wastes some of the factors which
must be considered are:
- "Compatibility"of the liner material with
the particular hazardous waste to be con-
fined. For example, many wastes will con-
tain organic materials even in small
amounts which can swell or deteriorate a
liner or damage the seams. Such liners
as butyl, EPDM and asphalt would probably
103
-------
be damaged by wastes containing hydrocar-
bons. Also, some impermeable soils can
lose their impermeability when impounding
strong acids, bases or brines. Some can
be seriously affected by increased temp-
eratures.
- The level of permeability allowable for a
given waste. At times very low permeabil-
ity is required.
- Lifetime required and the level of imperm-
eability needed over a period of time.
- Whether the liner will be exposed to sun-
light and weather. Some of the liner ma-
terials, such as soils, can lose imperm-
eability due to freeze-thaw and drying or
by wave action of the liquid being im-
pounded. Synthetic membrane films, such
as polyvinyl chlorides, can become exces-
sively brittle either due to loss of plas-
ticizer by evaporation or due to polymer
degradation resulting from ultraviolet
light. Butyl can crack because of ozone
on extended exposure.
Specific materials for exposure in this
test program were selected on the basis of
these factors.
OBJECTIVES OF PROJECT
- To determine the effects of exposure to
various wastes upon the physical proper-
ties, particularly the permeability, of
liner materials over a period of 24 moiths.
- To estimate the effective lives of twelve
liner materials exposed to six types of
nonradioactive hazardous waste streams
generated by industry under conditions
which simulate those encountered in hold-
ing ponds, lagoons, and landfills.
- To develop the information needed for rec-
ommending different lining materials for
confining hazardous wastes.
- To determine the durability and cost ef-
fectiveness of the various liners for con-
fining different hazardous wastes.
- To develop a method for assessing the rel-
ative merit of the various liner materials
for specific applications and for deter-
mining service lives.
EXPERIMENTAL PROGRAM
In our overall experimental program,
we shall:
- Expose liner specimens of about one square
foot area, with seams, sealed in the bot-
tom of cells containing approximately one
foot of waste above the specimen.
- Measure the seepage of the waste through
the liner and determine the effect on
properties of the liners over a two-year
period.
- Perform exploratory tests of liners and
wastes to determine their "compatibility"
and suitability for long-term exposure
tests,
- Determine the effects on the properties
of a wide range of liner materials im-
mersed in wastes.
- Expose specimens of the liners to the
weather, observe and measure changes in
properties.
- Expose samples of selected liners to the
weather and wastes simultaneously by
placing in partially filled troughs.
- Fully characterize each of the hazardous
wastes.
The main effort in this project will be
the exposing of selected liner specimens in
the one cubic foot cells and determining the
effects of the exposure upon the liners and
their performance. A schematic drawing of
the cells is shown in Figures 1 and 2.
The cell shown in Figure 1 is for the poly-
meric membrane liners with a seam; that
shown in Figure 2 is for the admix liner
specimens which are thicker and must be
mounted in a spacer between the base and the
tank containing the waste. These cells are
fabricated from steel and coated with a
chemically resistant epoxy coating. The
base of the cell is filled with a chemically
inert high quality silica in order to pre-
vent reactions of the waste which may seep
through the liner. These cells will be dis-
assembled after one and two years exposure
and the liners recovered and tested. The
cells, 144 in all, are placed on a rack at
the Richmond Field Station of the University
of California, Berkeley.
104
-------
Fisure 1. Schematic drawing of exposure cell for membrane liners. Exposed
area of liner la 10" x 15" and depth of the uaate la one foot.
asket or Epoxy Resin Seal
Sludge Column
11 Gauge steel
I0"nl5"xl2" High
With Weld Z'/z
Flange
Edge and Corners Epoxy Sealed
COMPACTED BARRIER SPECIMEN
After obtaining the wastes, it was
recognized that several of the liners
would not withstand exposure to certain
wastes and, thus, some combinations were
eliminated from the long-term testing. A
series of exploratory experiments were run
to determine which combinations should be
tested. These exploratory tests were of
three types:
- Immersing 1" x 6" strips of the membrane
liners in the wastes in one-gallon contain-
ers and observing the effects, e.g. swell,
over a period of several weeks.
- Mixing modified bentonites with sand in a
ratio of 1 to 4 parts by weight and placing
a one-inch layer in the bottom of perfo-
rated 400 ml polyethylene beakers, soaking
for one week, and then pouring two inches
of hazardous wastes on top and observing
seepage through the liners.
- Sealing permeability test specimens of
asphalt concrete, soils, and soil cement
in two-inch glass tubing, placing two
inches of strongly acidic and basic haz-
ardous wastes above them, and observing
seepage through the respective liners.
As we have a large number of different
liner materials, but could only test a lim-
ited number mounted in the bases of the
cells, it was felt that a wider study of
the other materials could be performed by
immersing specimens in the waste tanks
which are part of the exposure cells. These
specimens will be hung in the wastes and re-
moved at various times to have their phys-
ical properties determined.
Many liners for ponds are exposed to
the weather and sunlight. In some cases,
it is necessary to cover these liners to
avoid the degrading effects of wind and sun-
light. Consequently, we plan to expose sam-
ples on roof-aging racks in Oakland to sun-
light and weather and determine the effects
on the properties. In addition, the ef-
fect of raising and lowering the level of a
pond may cause degradation at the water
line. We, therefore,plan to expose se-
lected liners in troughs in which both sun-
light and wastes can interact with the lin-
er material.
We recognize that only a limited num-
ber of wastes can be used in these tests.
In order to give the data some broad use-
fulness, we shall characterize the wastes
fully. This characterization will be per-
formed by the Sanitary Engineering Research
Laboratory of the University of California
at Berkeley. We believe that extrapola-
tions can be made to a wide range of haz-
ardous wastes by using the experience ob-
tained on the highly characterized wastes.
As the ultimate failure of a liner
will be when it no longer holds the waste
which it is impounding, observation of the
seepage of the waste through the liners
will be made and the wastes will be anal-
yzed. It is expected that most of the lin-
ers will not allow seepage within the two-
year period. In order to make estimates
of the service life of these materials, the
normal physical properties will be meas-
ured as a function of time. It is felt
that some of the tests will correlate with
liner performance and service life. The
tests which will be run on the polymeric
membrane liners are shown in Table II;
tests for the admix materials are shown in
Table III.
105
-------
TABLE II. TESTING OF POLYMERIC MEMBRANE
LINERS.
Water permeability - ASTM E96.
Thickness.
Tensile strength and elongation at break,
ASTM D412.
Hardness, ASTM D2240.
Tear strength, ASTM D624, Die C.
Creep, ASTM D674
Water absorption or extraction at RT and
70°C, ASTM D570.
Seam strength, in peel and in shear,
ASTM D413.
Puncture resistance - Fed. Test Method Std.
No. 101B, Method 2065.
Density, ash, extractables.
TABLE III. TESTING OF ADMIX LINER MATERIALS.
Water permeability - Back pressure perme-
ameter (10).
Density and voids - ASTM D1184 and D2041.
Water swell - Calif. Div. of Hwys 305.
Compressive strength - ASTM D1074.
Viscosity, sliding plate of asphalts - Cal-
if. Div. of Highways 348.
PROGRESS OF WORK AND PRELIMINARY REPORT
Selection of Liners for Exposure
After reviewing the available liner ma-
terials, five admix type and eight specific
polymeric membrane materials were selected
for exposure testing as liners in the cells.
These materials are listed in Table IV.
The admix liners were selected or de-
signed to yield permeability coefficients
of 10 cm/sec or less. In the case of the
soil cements and compacted fine-grain soils,
a variety of compositions was compacted in
order to achieve the desired coefficient of
permeability. An extended search was made
for native fine-grain soils which would
have the level of permeability desired and
minimal interaction with the wastes. Such
a material was found at Mare Island, Cali-
fornia; it is a sediment of high silica con-
tent from the Sacramento River. The coeffi-
cients of permeability of the admixed ma-
terials are presented in Table V.
TABLE IV. LINER MATERIALS FOR HAZARDOUS
WASTES.
Thickness
Soil and Admix Materials in inches
Asphalt emulsion on nonwoven
fabric
Compacted native fine-grain soil
(from Mare Island)
Hydraulic asphalt concrete
Modified bentonite and sand
Soil cement with seal
Polymeric Membranes:
Butyl rubber reinforced
Chlorinated polyethylene (CPE)
Chlorosulfonated polyethylene
(Hypalon)- reinforced
Elasticized polyolefin (3110)
Ethylene propylene rubber (EPDM)
Polychloroprene (neoprene) rein-
forced
Polyester (experimental)
Polyvinyl chloride (PVC)
0.3
12.0
2.5
5.0
4.5
Thickness
in mils
34
32
34
25
50
32
7
30
TABLE V. PROPERTIES OF ADMIX MATERIALS
Permeability
cm/sec
Emulsified asphalt
on nonwoven fabric
Hydraulic asphalt
concrete
Mare Island soil
10
-io-8-io-7
Modified bentonite 2 x 10
and sand (1 to 4,
by weight)
-7
Soil cement
5 x 10
Remarks
Densely
compacted
Fine-grain
plastic
soil
Clay swells
to form
tight bar-
rier
Mixed in
place and
compacted
The polymeric membranes were selected
to represent examples of different poly-
mers. The thicknesses were selected to be
as close to the same thickness as possible
and yet used practically. Both reinforced
and nonreinforced films are included. The
106
-------
butyl rubber, ethylene propylene rubber,
and polychloroprene are all vulcanized and
require vulcanizable cements for seaming.
The remaining membranes are based upon non-
vulcanizable polymers which can be seamed
by heat, solvents or solvent cements. The
experimental heat scalable polyester film
was included because of its good resistance
to oily wastes.
Selection of Hazardous Wastes
Six classes of hazardous wastes were
selected for this test. These are:
- Acidic sludge
- Alkaline sludge
- Cyclic hydrocarbon sludge
- Lead waste from gasoline tanks
- Oil refinery tank bottom waste
- Pesticide sludge
Twelve specific wastes were obtained
and a preliminary characterization was made
of each. Eleven of these wastes meet the
classification and are being included in ex-
posure tests.
The individual wastes and limited data
on each are given in Table VI. Both of the
tank bottom wastes are satisfactory for the
test; however, neither was received in ad-
equate quantity to place in the required
number of cells and a third tank bottom
waste was collected; it is not satisfactory
and a fourth is now being collected.
The wastes were received in 55-gallon
drums; several have been found to be in-
homogeneous with phase separations taking
place. In order to place uniform wastes
in the exposure cells, drums of each waste
are being blended before loading into the
individual cells.
Preliminary Results of Exposing Liners to
Caustic Wastes
In order to determine which liners
could be used in the experiment to confine
the particular wastes that had been col-
lected, exploratory exposure tests were
run. Also included in the testing were
all of the raw materials which would be
used in fabricating the exposure cells and
sealing the liners in the cells, i.e. the
epoxy coating and the various caulks and
sealants. The results of these exposure
tests which were run for approximately
three months are presented in TablesVII
and VIII.
It is quite apparent that some of the
liners will not resist some of these wastes,
i.e., the modified bentonite liners allow
the strong bases and strong acids to seep
TABLE VI. PRELIMINARY CHARACTERIZATION OF .WASTES.
CLASS OF WASTE
Strong Acid
Strong Base
Tank Bottom
Lead
IDENTIFICATION OF
SPECIFIC WASTE
"HFL"
"HN03, HF. HOAC"
"Slopwater"
"Spent Caustic"
"Weed Oil"
SOLIDS, %
4.8
1.5
12.0
11.3
7.5
"Tergol Clay"
"Low lead gas washing" 7.2
"Gasoline Washwater" 7.9
"Mohawk leaded" 7.9
Saturated and
Unsaturated oil
Pesticide
"Weed Killer"
2.7
TOTAL
2.48
0.77
22.43
22.07
1.81
71.8
1.52
0.32
0.73
ca 36
0.78
VOLATILE
0.29
0.12
5.09
1.61
1.00
ca 39
0.53
0.17
0.60
^a 31
0.46
REMARKS
30/60 highly aro-
matic oil/water.
Oil and clay.
34 ppm lead.
11 ppm lead.
5 ppm lead
Note: Underlined wastes are included in the exposure testing at the base of the cells.
107
-------
o
CO
TABLE VII
EFFECT OF IMMERSING LINER MATERIALS IN HAZARDOUS WASTES
Page 1 of 2
Unit: %increase in area of portion of strip immersed
Waste No.
Membrane Liner
Polyvinyl chloride (PVC)
reinforced with nylon
reinforced with nylon
Chlorosulfonated Polyethylene (Hypalon) nylon reinforced
cured and reinforced
Chlorinated polyethylene (CPE)
nylon reinforced
polyester reinforced
polyester reinforced
Ethylene propylene rubber (EPDM)
Polychloroprene (neoprene)
Butyl Rubber
nylon reinforced
polyester reinforced
nylon reinforced
reinforced with polyester
nylon reinforced
Lead Wastes
Strong Acid
No.
10
11
17
40
49
59*
67
71
6*
50
55
12*
38
39
48
73
HFL
(1)
CC
NVC
NVC
NVC
-
NVC
NVC
NVC
NVC
NVC
NVC
NVC
NVC
-
NVC
HN03
(2)
NVC
NVC
NVC
NVC
-
NVC
NVC
a
ao.
NVC
NVC
NVC
NVC
NVC
.
NVC
Strong Base
Slop
Spent
Water Caustic
(3)
HDS
HDS
HDS
HDS
-
HDS
HDS
HDS
10 in
NVC
NVC
NVC
NVC
NVC
-
NVC
a Complete
8
26*
9
37
42
43
4/
56
74
NVC
NVC
CC
NVC
NVC
-
-
NVC
NVC
NVC
NVC
SCR
NVC
R
-
-
NVC
NVC
NVC
NVC
CC
NVC
NVC
-
-
SHD
a
aNeoprene
22
24
44
57*
NVC
NVC
-
NVC
NVC
NVC
-
NVC
NVC
NVC
NVC
(4)
NVC
NVC
NVC
NVC
-
NVC
NVC
NVC
swell each
NVC
NVC
NVC
NVC
NVC
-
NVC
Tank Bottom
"Weed
Oil"
(5)
NVC
NVC
+11
+24
+3
+26
+5
CC
direction,
R
6
R
R-92
R
Ra
-
Tergol
Clay
(6)
-17 HDS
-12 HOS
-10 HDS
SHD
-
-6
-6 SHD
-8 HDS
curled, and
NVC
NVC
6
NVC
NVC
_
NVC
Gasoline
Lo Pb
Washing
(7)
NVC
NVC
NVC
NVC
-
NVC
NVC
NVC
delaminated.
NVC
NVC
NVC
NVC
NVC
_
BLS
Wash
Water
(8)
NVC
NVC
NVC
NVC
-
NVC
NVC
NVC
NVC
NVC
NVC
NVC
NVC
-
NVC
Sat 6c Pesticide
Unsat
Oil
(9)
-10 HDS
-5 HDS
-6 HDS
SHD
-
SHD
SHD
-6 HDS
40
36
11
16
9
_
2-CC
Weed
Killer
(10)
NVC
NVC
NVC
NVC
-
NVC
NVC
NVC
NVC
~
NVC
NVC
NVC
NVC
-
loss of tear strength
NVC
NVC
NVC
NVC
NVC
-
•
NVC
NVC
75
90
111
67
REV
10
b
100
NVC
24
60
77
NVC
NVC
13
•
3
NVC
NVC
NVC
NVC
NVC
NVC
-
_
NVC
NVC
NVC
NVC
NVC
NVC
NVC
-
•
NVC
NVC
77
70
42
21
5
48
•
10
NVC
_
NVC
NVC
NVC
NVC
-
NVC
.
ok but reinforcing fabric (polyester) dissolved.
NVC
NVC
.
NVC
68
91
76
67
64
59
13
20
NVC
NVC
_
Nvn
NVC
NVC
_
NVH
69
89
94
NVC
_
_
uvr.
-------
TABLE VH continued)
EFFECT OF IMMERSING LINER MATERIALS IN HAZARDOUS HASTES
Page 2 of 2
Unit: % increase in area of portion of strip . jnersed
Lead Wastes
Strong Acid
Waste No.
Membrane Liner
Elastlcized polyolefin (3110)
Thermoplastic polyester
Polyurethanee P°|"es " reinforced
polyes er reinforced
reinfo ced
nylon einforced
Misc. liner materials - Coal Tar Pitch + PVC
Emulsified Asphalt on Petromat
Sealing Materials - Butyl cauVt
Polyureth.me caulk
Polysulfide caulk
| — i Teflon fiponflp rod
O
Neoprene sponge
No.
36
41
69
75
45
46
51
70
72
52
58
63
64
66
68
3
HFL
(1)
NVC
NVC
NVC
NVC
-
-
CC
cc
NVC
NVC
NVC
-
NVC
NVC
NVC
HN03
(2)
NVC
NVC
NVC
NVC
-
-
NVC
NVC
NVC
SCR /BLS
NVC
R
SPT 16.2
rev
NVC
SCR
Strong Base
Slop
Water
(3)
NVC
NVC
a
a
-
-
CC
CC
11DS
NVC
NVC
SFT 16,2
SCR
NVC
SHR
Tank Bottom
Spent "Weed Tergol
Caustic Oil1
: (4)
NVC
NVC
NVC
NVC
"Black
-
-
NVC
NVC
NVC
NVC
NVC
NVC
NVC
NVC
NVC
(5)
49
42
12
18
rubs of ft
50
44
2
33
28
17
R
R
SFT 16.2
NVC
ABS
38
Clay
(6)
17
18
NVC
NVC
indicating possible
-
-
NVC
NVC
NVC
R
_
-
NVC
ABS
SHR
Lo Pb
Washing
(7)
NVC
NVC
NVC
NVC
dissolving
:
-
cc
NVC
NVC
NVC
NVC
NVC
NVC
NVC
SHR
Gasoline Sat 6. Pesticide
Wash
Water
(8)
NVC
NVC
NVC
NVC
:
-
NVC
NVC
NVC
NVC
NVC
BLS
NVC
NVC
SHR
Unsat
Oil
(9)
32
24
NVC
9
:
-
14
5
NVC
R
.
-
NVC
ABS
SHR
Weed
Killer
(10)
NVC
NVC
NVC
NVC
-
-
NVC
NVC
BLS
.
.
-
.
SHR
* Materials incorporated in cells - underlined,
- Material not tested in the waste noted
Waste No. 1.Hydrofluoric acid
2«Hydrofluoric, acetic and nitric acids
3.Slopwater
4.Spent caustic
5.Weed oil (highly aromatic) 307,;
water 707. (Tank bottom waste)
6.Tergol-clay
7.Low lead gas washings
8.Gasoline wash water
9.011 (saturated and unsaturated)
10.Pesticide, a weed killer
R - Removed specimen from waste because of excessive swelling or disintegration
NVC - No visible change
SCR - Surface cracking and hardening
HDS - Hardened and shrank
SHD - Slightly hardened
DIS - Dissolved or disintegrated
BLS - Blistering of surface
SFT-1 - Softened above waste
SFT-2 - Softened in waste
SS - Slightly swollen
DEL - Delaminated
CC - Color change
REV - Reverted
Matrecon, Inc.
12/1/75
-------
TABLE VIII
EFFECTS OF PLACING WASTES ABOVE TEST SPECIMENS OF ADMIX MATERIALS
Time to first passage of wastes or fraction of waste through material» in days
Lead Wastes
Strong Acid Strong Base
Waste No.
Treated Bentonite-Sand Mixtures
A -
B -
Native Soil (Mare Island)
Soil-Cement containing Rice
Hull Ash
Soil-Cement, Portland
HN03 Slop
HFL Water
(1) (2) (3)
4.8 1.5 12
17d 3d 2d
> 44d 3d 2d
- >19d >19d
>19d >19d
Bubbling NVC
on
Surface
>19d >19d >19d
Surface NVC
Softer
Spent
Caustic
(4)
11.3
3d
3d
2dc
NVC
Tank Bottom
"Weed Tergol
Oil" Clay
(5) (6)
3'rt >47d
>47d >47d
Gasoline Sat &
Lo Pb Wash Unsat.
Washing Water Oil
(7 ) (8) (9)
7.2
> 47d > 47d 14d
>47d >47d >47d
Pesticide
Weed
Killer
(10)
3 See notes on Table VII.
Some dampening of bottom; neutral to litmus .
c Fluid passing through is basic.
NVC - no visible change to surface of specimen in 19 days .
-------
through in a relatively short time. Also,
almost all of the membrane liners tend to
swell in the oily wastes. Such combina-
tions are not being tested as liners in
the bases of the cells in the long expos-
ure tests. In the shorter tests, a var-
iety of these materials can be tested by
immersion in the various wastes and their
properties as affected by exposure can be
measured.
These exposure tests have been init-
iated and will require at least a year be-
fore results are available. Shorter term
immersion tests will also be run and the
results will be available at an earlier
date.
ACKNOWLEDGEMENTS
The work which is reported in this
paper is being performed under Contract
68-03-2173, "Evaluation of Liner Materials
Exposed to Hazardous and Toxic Sludges",
with the Environmental Protection Agency,
National Environmental Research Center.
The author wishes to thank Robert E.
Landreth, Project Officer, for his support
and guidance in this project. The author
also wishes to acknowledge Dr. Clarence
Golueke, who is Principal Investigator for
the Sanitary Research Engineering Labora-
tory, University of California, Berkeley,
who is responsible for the characterization
of the individual wastes, and the efforts
of R. M. White and the technicians of
Matrecon, Inc., in carrying out the exper-
imental work involved in this project.
REFERENCES
1. U.S. Environmental Protection Agency,
"Report to Congress on Hazardous Waste Dis-
posal", June 30, 1973.
2. R. L. Cummins, Report to Public Health
Service, Bureau of Solid Waste Management,
1970 (PB 214-924) "A Review of Industrial
Solid Wastes".
3. P.H. McGauhey and C.G. Golueke, "Con-
trol of Industrial Solid Waste" from book:
"The Industrial Environment - Its Evalua-
tion and Control", U.S. Department of
Health, Education and Welfare (1973).
4. T.J. Sorg, AIChE 68 (122) 1-5 (1972),
"Industrial Waste Problems".
5. Dallaire, Gene, "Tougher Pollution Laws
Spur Use of Impermeable Liners", Civil En-
gineering, ASCE, May 1975, p. 63.
6. Geswein, Allen J., "Liners for Land
Disposal Sites - An Assessment", EPA Re-
port EPA/530/SW-137, March 1975.
7. H. E. Haxo, "Assessing Synthetic and
Admixed Materials for Lining Landfills,"
EPA Symposium, "Gas Leachate from Land-
fills: Formulation, Collection and Treat-
ment," Rutgers University, March 26 and
26, 1975.
8. Jack Lee, Pollution Engineering, "Se-
lecting Membrane Pond Liners," January
1974.
9. Stewart, W.S., "State-of-the-Art Study
of Landfill Impoundment Techniques", EPA
Project R-803585, May 31, 1975.
10. B.A. Vallerga and R.G. Hicks, J. Ma-
terials 3^ (1) 73-86 (1968) "Water Permeab-
ility of Asphalt Concrete Specimens Using
Back-Pressure Saturation".
Ill
-------
LINERS FOR DISPOSAL SITES TO RETARD MIGRATION OF POLLUTANTS
Wallace H. Fuller, Colleen McCarthy,
B.A. Alesii, and Elvia Niebla
Soils, Water, and Engineering
University of Arizona, Tucson, AZ 85721
ABSTRACT
The potential hazard of polluting constituents from solid waste deposited on land is
influenced by the rate they migrate through the soil and/or geologic material to under-
ground water sources and links into the food chain. The rate is controlled by the nature
of (a) the solution carrying the pollution constituent, (b) the soil and geologic material
through which the constituents move, and (c) the constituent itself. The most prominent
properties of the above three habitats which influence migration rate were identified.
The measurable soil parameters which most affect attenuation of the selected trace ele-
ments (As, Cd, Cr, Cu, Hg, Ni, Pb, Se, V, and Zn) are: clay content, lime, hydrous
oxides of Fe, and surface area per unit weight of material. The individual trace elements
migrated at different rates through soils. The presence or absence of organic constituents
in the influent is a factor in Hg attenuation. The following liner materials are sug-
gested for study on a pilot-plant basis: (a) agricultural limestone, (b) hydrous oxides
of Fe (ferrous sulfate mine waste), (c) lime-sulfur oxide (stack-gas waste), (d) certain
organic wastes, and (e) soil sealants (independent of the U.S. EPA grant). Preliminary
research on limestone and Fe hydrous-oxide liners indicates these materials have a marked
retarding influence on the migration rate of many trace elements.
INTRODUCTION
Wastes from which polluting constitu-
ents originate, in large part, are depo-
sited either directly on land or end up on
land, indirectly, from air and water trans-
port systems. The pollution hazard is
intensified greatly if the constituents
tend to migrate through the soil and/or
geologic debris to underground sources of
drinking and irrigation water (Weddle and
Garland, 1974). Such wastes, whether muni-
cipal, agricultural, or industrial also may
pollute through the food chain as a result
of adsorption by food and field crops from
contaminated soil and water sources.
Although sanitary landfill is one of
the approved methods of solid waste dispo-
sal, rainwater may permeate the waste,
accumulate, and solubilize potentially
hazardous constituents. Some of these
constituents (including heavy metals) may
undergo a series of reactions possibly
reprecipitating and resolubilizing several
times as they migrate through the landfill
and underlying earth materials before
finally reaching an underground water
source (Miller, et al., 1974). The rate
of migration into underground water sources
determines the level of potential pollution
hazard. The rate of migration varies from
those constituents that migrate almost
uninhibited to those that may be almost
wholly immobilized. This rate is controlled
by the nature of the three main components
of the wastes habitat; namely, (a) the solu-
tion carrying the pollution constituent,
(b) the porous medium through which the
constituent is being transported, (i.e.,
the soil or geologic material) and (c) the
constituent itself.
112
-------
Under the usual condition of land dis-
posal, the above waste habitats which in-
fluence migration rate receive no particu-
lar attention for favorable alteration.
Yet, alteration of the pollutants' in situ
habitat can decelerate migration. Modern
land disposal management dictates that
those factors influencing attenuation of
pollutants, whether centered in the soil,
in the leaching solution, or in the con-
stituent itself, be identified and put to
practical work to help control migration.
The mass sampling surveys of garbage
dumps, landfills, and indeed a wide vari-
ety of disposal sites throughout the U.S.
reveal a great variability in the concen-
tration of pollutants in the waters sur-
rounding and below sites (Weddle and
Garland, 1974). To a certain extent this
situation may be expected, since disposal
sites often are located in coarse textured
materials, along river bottoms, abandoned
gravel and sand pits, rock quarries, and
in gaping aggregate-removal sites of the
building trades. Basins of such porous
media are virtual sieves which retain only
the large particles and permit soluble sub-
stances to pass through (Garland and
Mosher, 1974). Other basins which have
been located in finer textured material
have been filled with little knowledge
developed concerning the physical charac-
teristics of soil and geologic media (i.e.,
stratifications of texture, structure,
density, hydraulic conductivity, cracks,
etc.) surrounding the disposal site. Be-
cause of the great variability associated
with disposal sites as well as solid waste
disposal material, and the difficulty of
accurately characterizing the heterogenic
physical nature of the walls, floor, and
surrounding earth materials, it is manda-
tory that (a) solid waste deposits be
located in soil and/or geologic material
most favorable for retaining potential
pollutants generated by the waste, and (b)
something be done to the site pit to insure
retention maximization. Pollution control
of wastes should not be left to the
chances of nature. Studied location selec-
tion and site management are necessary.
The development of inexpensive liners from
waste material is one method to help in-
sure retention of hazardous constituents
deposited on land. For this discussion,
liners may be described as thin layers of
porous material through which liquid must
pass. They assume the position of control-
lable variables because disposal excava-
tions, typified by landfill sites, may be
lined easily to various thicknesses of
these materials and packed to densities to
achieve a favorable flux. In this way,
leachates and other wastewaters from dis-
posals must pass through a control barrier
before entering the natural soil and geo-
logical material.
One of the main requirements of most
landfills is that they leak. Leachates
collecting from natural precipitation, as
well as that applied, must escape. Another
requirement is the retention of pollutants
within narrow limits of the sides and floor
of the landfills. The soils and geologic
material associated with landfill sites,
vary greatly ranging from those that pro-
vide no effective attenuation to those that
are somewhat retentive. All sites require
modification if migration of pollutants is
to be retarded because all natural mate-
rials permit migration of at least some
polluting constituents found in waste
leachates. Liners provide the mechanisms
necessary to retain, at least to some
extent, the undesirable migration of pollu-
tants. This is a far greater task than
completely sealing the site boundaries,
although the latter may be necessary at
some sites.
To develop a practical site-liner
program it was necessary to identify
specific factors or properties of each of
the three components of the pollutant habi-
tat which influence rate of migration.
The most prominent of these factors are
described by Fuller and Korte (1976), and
Korte et al. (1976a). A more recent com-
plete coverage of this subject appears in
a U.S. EPA contract report by Fuller (1976).
Some of the on-going research at the
University of Arizona relating to attenu-
ation of trace elements in soils also will
be reported by Korte et al. (1976b), Alesii
et al. (1976), and Skopp et al. (1976), at
this symposium. Among the outstanding soil
parameters which influence the attenuation
of the 12 selected trace elements are the
content of clay, lime, and hydrous oxides.
The main thrust of this research re-
port will be to suggest possible low-cost
waste material liners for disposal sites
to retard migration of trace elements,
including some heavy metals. In the chemi-
cal literature "heavy metals'1 generally
113
-------
refers to those metals which have densities
>5.0. In this report "trace elements" will
refer to As, Be, Cd, Cr, Cu, Fe, Hg, Ni,
Pb, Se, V, and Zn.
MATERIALS AND METHODS
SOILS
Eleven soils representing 7 major
orders were collected throughout the U.S.
at depths below the organic laden top-soil.
Although the soils were not collected en-
tirely in the C horizons and parent mate-
rial profile position common to the loca-
tion of many landfills, the selection
provides an opportunity for a clearer eval-
uation between soil characteristics and
attenuation, the main purpose of this
research. Furthermore, disturbed soil
material, taken from landfill excavations
for covering, enveloping, "cell" encasing,
etc., usually is required and accepted as a
management practice. Other land deposits
such as the containment from air and water
pollution involves soil contact. Thus, if
others characterize a soil-like material
from a greater depth, for example, they
can take note of the characteristics of
the soil material used in this study and
select the one most similar to their loca-
tion. Knowledge of the behavior of domi-
nant and readily measurable soil parameters
in attenuation provides a basis for estab-
lishing control-prediction.
Some physical characteristics of the
soils collected are shown in Table 1. The
clay contents range from 3 to 61%. The
clay minerals of the >2y separate of the
11 soils varied widely from largely mont-
morillonite-type in Anthony s.l. and
Chalmers si.c.l. to largely Kaolinite-type
in Davidson and Molokai clays and Wagram
l.s. The pH values range from 4.2 for the
Ultisol, Wagram l.s. to 7.8 for the alka-
line Aridisols, Anthony s.l. and Mohaveca
c.l. Other characteristics are described
in detail in earlier publications by Fuller
and Korte (1976).
MUNICIPAL LANDFILL LEACHATE
The natural leachate used as a vehicle
for carrying the individual "spiked" poten-
tial pollutants (Al, As, Be, Cd, Cr, Cu,
Hg, Ni, Pb, Se, V, and Zn) came from a
municipal solid waste landfill (Korte,
Niebla, and Fuller, 1976). The trace ele-
ment was "spiked" at concentrations of 1000
ppm for Al, Cu, and Pb, and 100 ppm for all
other elements although lower ranges of 25
to 85 ppm also were used for those elements
which form anions. Such concentrations
were established for convenience of iden-
tifying attenuation effect of the liners
since the individual elements differ widely
in their rate of migration through the
liner barriers.
LINER MATERIALS
Liner materials considered for study
were ground limestone (CaC03), sand treated
with hydrated FeS04, and soil treated with
hydrated FeS04. The ground limestone is a
commercial product from Cedar Bluff, KY,
commonly used for agricultural soil appli-
cations. Particle size analysis of this
98% pure CaCOs appears in Table 2. Two
particle size distributions of the lime-
stone were used, namely (a) the original
material as it is sold, and (b) the same
material sieved to pass a 0.5 mm screen.
The treated sand and soil liners were
prepared by spraying the sand and soil with
aqueous FeS04 to attain a final FeS04«7H20
concentration of 1% by weight.
PROCEDURE
A series of "batch" studies were con-
ducted preliminary to the more definitive
"column" studies. The batch technique is
simpler and less expensive so was used
initially to determine (a) maximum adsorp-
tion interaction between selected trace
elements and limestone, (b) appropriate
concentration levels of spiked element
which would provide measurable data in the
column studies, and (c) the effect of lime-
stone particle size when used as a liner
material.
The details of the soil column proce-
dure have been described by Korte, et al.
(1976) and by Fuller (1976). In brief, 10-
cm lengths of 5 cm PVC pipe were filled
with soil to form a vertical soil column.
The procedure and equipment used in the
114
-------
TABLE 1. CHARACTERISTICS OF THE SOILS
Soil
Wagram
(N.Carolina)
Ava
(Illinois)
Kalkaska
(Michigan)
Davidson
(N.Carolina)
Molokai
(Hawaii)
Chalmers
(Indiana)
Nicholson
(Kentucky)
Fanno
(Arizona)
Mohave
(Arizona)
Mohaveca
(Arizona)
Anthony
(Arizona)
Order pH CEC
meq/
lOOg
Ultisol 4.2 2
Alfisol 4.5 19
Spodosol 4.7 10
Ultisol 6.2 9
Oxisol 6.2 14
Mollisol 6.6 26
Alfisol 6.7 37
Alfisol 7.0 33
Aridisol 7.3 10
Aridisol 7.8 12
Entisol 7.8 6
EC
Umhos
/cm
225
157
237
169
1262
288
176
392
615
510
328
Surface
Area
m2
8
62
9
51
67
126
121
122
38
128
20
Free
Iron
Oxides
%
0.6
4
1.8
17
23
3.1
5.6
3.7
1.7
2.5
1.8
Total
Mn Sand
ppm %
50 88
360 10
80 91
4100 19
7400 23
330 7
950 3
280 35
825 52
770 32
275 71
Texture
Silt Clay Class
7 7
fo /o
loamy
8 4 sand
silty
60 31 clay
loam
4 5 sand
20 61 clay
25 52 clay
silty
58 35 clay
loam
47 49 S"ty
clay
19 46 clay
sandy
37 11 loam
clay
28 40 loam
sandy
14 15 loam
Predominant
Clay Minerals*
Kaolinite,
Chlorite
Vermiculite
Kaolinite
Chlorite,
Kaolinite
Kaolinite
Kaolinite
Gibbsite
Montmorillonite ,
Vermiculite
Vermiculite
Montmorillonite,
Mica
Mica,
Kaolinite
Mica,
Montmorillonite
Montmorillonite
Mica
*Listed in order of importance
-------
TABLE 2. A COMPARISON OF PARTICLE SIZE DISTRIBUTION OF TWO COMMERCIAL
AGRICULTURAL LIMESTONE MATERIALS FROM TWO KENTUCKY SOURCES
Sieve Size
-2.5 to -2.0
-2.0 to -1.5
-1.5 to -1.0
-1.0 to -0.5
-0.5 to 0
0 to 0.5
0.5 to 1.0
1.0 to 1.5
1.5 to 2.0
2.0 to 2.5
2.5 to 3.0
3.0 to 2.5
3.5 to 4.0
Classes
-5.66
5.66 to 2.80
2.80 to 2.00
2.00 to 1.40
1.40 to 1.00
1.00 to 0.71
0.71 to 0.50
0.50 to 0.355
0.355 to 0.250
0.250 to 0.180
0.180 to 0.125
0.125 to 0.090
0.090 to 0.063
0.060 to 0.050
< 0.050
USDA Texture
Classes
gravel
very coarse
sand
coarse
sand
medium
sand
fine
sand
very fine
sand
silt + clay
Sieve Si
Source of
Lexington
0.9
17.3
13.2
15.2
11.4
10.2
7.5
8.3
6.0
3.0
2.4
1.5
1.0
0.8
1.2
ze and
Limestones
Cedar Bluff
ci
0
5.1
4.4
6.8
7.8
8.3
9.4
12.5
10.2
6.7
6.3
4.8
6.0
1.9
9.9
116
-------
quartz sand column study to evaluate the
attenuating effect of liner material inde-
pendent of soil differed from the soil
column studies only in that acid washed
quartz sand was used instead of soil. The
top 2 cm of the column consisted of the
liner material to be evaluated. The solu-
tion carrying the spiked trace element
being studied was in all cases natural mun-
icipal landfill leachate. The solution was
displaced through the column until the ef-
fluent concentration of the spiked trace
element was equal to the concentration in
the influent.
Potential liner-soil medium combina-
tions are:
1. Limestone layered over quartz sand,
2. Limestone layered over soil,
3. FeS04 treated sand layered over quartz
sand,
4. FeS04 treated sand layered over soil,
5. FeS04 treated soil layered over quartz
sand, and
800
6. FeS04 treated soil layered over soil.
RESULTS AND DISCUSSION
This presentation is represented by
a limited amount of data since the liner
phase of the grant program has been under-
way only a few months. Agricultural lime-
stone and the hydrous oxides of iron
received the most attention.
LIMESTONE
Tbere was essentially no difference in
influence on adsorption of trace element
attributable to particle size of limestone,
so data from only the sieved limestone
(<0.5 mm) are given here. The degree of
adsorption varied among trace elements and
among different contact time intervals
(Figure 1). Lead, Cu, and Al, for example,
O
00
oo
5 1 2 4 24 48 .5124 2448
2 4 24 48 .51 24 2448 .5124 2448
CONTACT TIME - Hours
.51 2 4 24 48
Figure 1. The adsorption of As, Be, Cd, Cr, Hg, Ni, Se, and Zn, irom
municipal landfill leachate, by Kentucky agricultural lime-
stone as influenced by time of contact.
117
-------
were adsorbed much more entensively than other elements (Table 3 and Figure 2)
TABLE 3. THE ADSORPTION OF TRACE ELEMENTS FROM MUNICIPAL LANDFILL
LEACHATE BY KENTUCKY AGRICULTURAL LIMESTONE AS AFFECTED
BY CONTACT TIME
Supernatant
Spiked
Element
Ni
Zn
Cr
Cr
Cd
Contact
Time
hours
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
PH
6.1
6.2
6.2
6.3
6.3
6.4
5.0
6.0
6.1
6.2
6.2
6.4
6.4
5.0
6.1
6.2
6.2
6.3
6.4
6.3
3.1
6.5
6.4
6.4
6.6
6.6
6.6
2.9
5.7
5.7
5.8
5.9
6.0
6.0
5.0
Ca
ppm
270
200
200
250
390
330
150
270
300
325
350
390
440
130
390
335
370
380
390
450
150
560
549
548
548
520
520
108
190
190
190
190
240
300
130
Spiked
Element
ppm
115
97
98
93
91
89
110
109
95
91
90
86
82
110
0
0
0
0
0
0
26
46
46
45
43
48
48
85
39
36
35
29
17
9
86
Element Sorbed
by Limestone
yg/g
0
120
120
170
190
210
-
50
150
190
200
240
280
-
260
260
260
260
260
260
-
380
380
387
435
375
380
-
470
500
520
570
700
770
_
118
-------
TABLE 3 (Continued)
Spiked
Element
As
As
Be
Hg
Se
Se
Supernatant
Contact
Time
hours
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
PH
6.3
6.3
6.4
6.3
6.4
6.5
5.1
6.2
6.2
6.3
6.4
6.5
6.6
5.1
5.6
5.7
5.6
5.7
5.7
5.8
4.0
6.3
6.4
6.4
6.4
6.5
6.4
5.1
6.2
6.3
6.4
6.3
6.5
6.5
5.1
6.3
6.2
6.2
6.4
6.5
6.5
4.9
Ca
ppm
270
270
270
325
370
370
130
346
303
333
371
415
443
136
480
480
510
500
500
570
130
270
320
330
370
380
420
130
260
260
285
300
325
370
130
314
328
300
300
377
391
189
Spiked
Element
ppm
37
35
33
32
35
36
43
90
90
90
90
90
90
103
64
64
63
60
54
35
103
83
69
63
43
23
21
100
8
5
4
3
4
5
35
45
45
22
23
23
23
96
Element Sorbed
by Limestone
yg/g
58
73
95
99
73
61
-
133
133
133
133
133
133
-
380
383
393
427
482
590
-
167
311
369
570
769
794
-
267
295
310
319
305
298
-
510
510
745
760
770
725
—
119
-------
TABLE 3 (Continued)
Supernatant
Spiked
Element
V
Cu
Cu
Cu
Al
Pb
Contact
Time
hours
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
0.5
1
2
4
24
48
Tank
pH
6.3
6.5
6.5
6.5
6.5
6.6
4.6
5.3
5.4
5.9
6.1
6.3
6.3
4.5
5.4
5.4
6.0
6.4
6.4
6.4
4.5
5.1
5.1
5.9
6.3
6.3
6.3
4.5
5.9
5.9
5.9
6.0
5.9
6.0
3.7
4.7
4.9
4.5
4.9
5.8
5.9
3.1
Ca
ppm
400
427
501
500
500
500
115
120
130
240
280
320
540
150
327
366
944
963
1001
1025
130
332
404
1098
1175
1329
1146
130
2000
2160
2160
2160
2200
2200
130
160
180
160
180
300
380
130
Spiked
Element
ppm
89
77
76
75
76
75
110
500
395
30
4
4
5
540
875
832
19
8
8
6
1032
1186
1169
56
18
12
7
1385
0
0
0
0
0
0
850
645
590
560
433
13
2
865
Element Sorbed
by Limestone
yg/g
210
335
345
350
330
325
—
300
2500
5100
5360
5360
5360
-
1575
2000
10,025
10,125
10,124
10,126
—
1985
2153
13,286
13,665
13,725
13,772
-
8500
8500
8500
8500
8500
8500
-
2200
2700
3000
4325
8520
8630
-
120
-------
10,000 -
9000 -
8000
7000
g 6000
•rl
O
00
00
w
w
W
2
w
5000
4000
3000
2000
1000
Cu
Pb
X
X
X
.51 2 4 24 48
.51 2 4 24
48
Figure 2.
CONTACT TIME - Hours
The adsorption of Cu and Pb from
municipal landfill leachate by
Kentucky agricultural limestone
as influenced by time of contact.
and adsorption was enhanced by greater
contact time. Also, in general, the longer
contact time between the spiked effluent
and limestone increased the concentration
of Ca in the supernatant and raised the pH
level (Table 3). In certain cases such
as with Al, Cu, Cr, and Pb, adsorption by
the limestone did not reach a maximum
because the element was depleted from the
leachate within the time limit established.
Adsorption comparisons among these elements
must therefore be interpreted as less than
maximum, particularly during the longer
contact time intervals. The attempt to
overcome this by increasing the concentra-
tion of element "spiked" (As, Cu, Cr, Pb,
Cu) did not achieve the goal. The lime-
stone only succeeded in adsorbing more of
the element (Table 3).
Commercial grind limestone used in the
sand and soil column studies in which one
column was overlaid by 1 cm of limestone
and the other by washed quartz sand,
reduced the migration rate of Cd through
Wagram l.s. (Figure 3). A similar experi-
1.0
.9
o
w
g.6|-
H
H
.
00
3.
> • •
.1
1 cm LIME
LAYER
10
15
20
Figure 3.
PORE VOLUMES
Effect of ground agricultural
limestone liner on movement of
Cd through Wagram l.s.
121
-------
ment was undertaken to determine the migra-
tion rate of Ni with similar results
(Figure 4). Those elements which form
anions, namely, As, Cr, Se, and V appear
to be the least subject to retention by
limestone liners associated with soil
(Figure 4).
The results from the "batch" studies
appear to be in disagreement with those of
the "column" studies. The former makes it
80i-
appear that the anion-forming elements may
be retained by the limestone as well if
not better than some strict cations since
their adsorption from the leachate follows
this pattern. Compare Se, As, and Cr with
Ni and Zn in Figure 1, for example. Lime-
stone layered in soil columns, however, had
no measurable attenuating influence on Cr
above that of either Wagram l.s. or Anthony
s.l. alone (Figure 4). Cadmium and Ni
moved through soil material much less
TREATMENTS
A Limestone
D Fe Oxides
O None
TREATMENTS
-A Limestone
Figure 4.
3456
PORE SPACE DISPLACEMENT
The effect of ground agricultural limestone and Fe oxides on
element retention.
122
-------
rapidly in the presence of a thin limestone
layer than in its absence. Again compare
Figures 3 and 4. The data imply that ele-
ments adsorbed by limestone may or may not
lose their capacity to migrate when
exposed to the leaching action of the solu-
tion. In other words, different elements
may be held by the limestone at different
levels of tenacity and some are displaced
more readily than others. For example,
the anion-forming elements appear to be
held less tightly to the limestone than
most of the strict cations. The capacity
of limestone to adsorb an element from
solutions, as in the batch technique, does
not necessarily imply an extent or degree
of retention of that element against migra-
tion.
Another factor is the capacity of the
soil alone to react differently to possible
resulting constituents formed as the dif-
ferent elements pass through limestone.
The soil beneath the liner may become an
added factor in migration which may be
supporting, undoing, or indifferent to
the effects of the limestone depending on
the specific element involved. An example
in which the limestone layer appears
merely to offset the retention effect of
soil is shown in Figure 3 illustrating the
migration of Cd through a Wagram l.s. col-
umn. The soil in this case appears to be
independant of the limestone effects.
Although the "batch" technique does
not appear to reflect trace element migra-
tion characteristics through a limestone
layer as well as the "column" technique
(i.e., limestone layer over soil in a
column), the procedure still offers promise
as a rapid screening aid since many of the
12 trace elements were taken out of solu-
tion similarly by both techniques.
When limestone liners are used on acid
soils, unnecessary mixing should be avoided
since the limestone will react with the
soil in neutralizing the acidity. Thus its
potential as a barrier for attenuation will
be consumed or inactivated to a degree
directly proportional to the extent it dis-
appears in soil neutralization.
LIME-SULFUR OXIDES (STACK-GAS WASTES)
Lime-sulfur oxide slurries from air
pollution control of stack gases from coal
burning appear to have residual potential
for controlling pollution because of their
content of unspent lime and accumulation of
sulfur oxides. However, undesirable char-
acteristics may accompany the use of these
slurries. These are the presence of (a)
potential hazardous heavy metals, (b) cer-
tain slowly degradable hydro-carbons, and
(c) possible carcenogenic tars and resins.
The management of the slurries also offers
a problem in the transport and actual phy-
sical lining. In contrast, limestone
quarries have long been developed for agri-
cultural soil liming purposes and there-
fore offer much less of a transportation
problem of distance and quality of active
attenuating agent.
FERROUS-SULFATE (MINE WASTE)
Ferrous sulfate accumulates as a
waste product of copper mines. When ap-
plied to soil the iron sulfates rapidly
change to insoluble hydrous oxide forms.
The iron oxides have the capacity to coat
soil particles readily forming very thin
layers which are highly active in attenu-
ation processes. The effectiveness of
ferrous sulfate as an attenuator of pollu-
tants has been studied in column studies.
Quartz sand and soil columns were
prepared by sprinkling the corresponding
materials with ferrous sulfate mine waste
at a calculated rate of 1% Fe2C>3 by weight
of the upper 2 cm in the column. The
effect of hydrous oxides of Fe on attenu-
ation of Cr in Wagram l.s. (pH 4.2) and
Anthony s.l. (pH 7.8) are compared with
limestone in Figure 3. Chromium migration
is clearly retarded by the presence of the
hydrous oxides of Fe. Significant correla-
tions have been reported (Korte et al.,
1976; and Fuller, 1976) to occur between
percentage trace element retained by soil
and "free" iron oxide content. Davidson
and Molokai clay soils have the highest
content of extractable "free" iron oxides
and also unusual high capacity to retain
trace elements, which is over and above
clay effect. Another point of interest is
the highly significant correlation found
between iron oxide and total soil Mn. The
importance of Mn or hydrous oxides of Mn
is not fully known although it is sug-
gested to be less significant in attenua-
tion than iron oxides. The practical
research reported here agrees with the
pure-system chemical research of Jenne
123
-------
(1968) and Gadde and Laitinen (1974).
ORGANIC WASTES (e.g., NUTSHELLS)
The abundance of nut shells that are
available for disposal near sanitary land-
fills could be used as liners to assist in
retaining heavy metals and other trace
elements. They have great capacity for
adsorbing metallic ions. Under the anaer-
obic conditions of many disposal sites the
rate of decomposition of nutshells is par-
ticularly slow, probably in the order of
many years. Data on possible "leak" rate
for trace elements are not available.
Because of the organic matter content
of many wastes disposed of on land and in
soils, the question of chelation as a fac-
tor in downward migration of pollutants
through soils and geologic material under-
standably is raised. This is not a new
question but one which has been researched
by soil scientists involved with plant
nutrition and radioactive fall-out pollu-
tion control. For example, after many
years of intensively studying movement (or
lack of movement) of inorganic phosphates
in soils, P was found by Fuller and his
colleagues (see Hanna'pel et al,, 1964a,
1964b) to move downward through soil pri-
marily in organic chelates. The same move-
ment of 90sr and 45ca through soil was
found to be enhanced by the association
with organic matter and chelates (Fuller
et al., 1966, 1968; and L'Annunziata and
Fuller, 1968). Thus, organic chelation as
a mechanism influencing attenuation is
established. Such mechanisms likely func-
tion in long-term migration of polluting
constituents through soils not only with
landfill leachates and organic waste
waters, but also in long-term land appli-
cation of municipal sewage sludges. In-
deed, much research is needed before quant-
itative data can be generated in sufficient
amount to aid in prediction of organic
initiated contaminant movement through
soils and geologic materials.
SOIL SEALANT (SALT)
Some land disposal sites should be
made completely impervious to leaking.
Despite the existance of a low water table
overladen with soil materials possessing
naturally favorable attenuation properties,
if the water from the site reaches the cap-
illary fringes of the sub-surface water,
it will contain some soluble constituents
which could contribute to quality deterio-
ration. Many examples of this punctuate
the history of irrigated agriculture in
arid lands (Fuller, 1975; Muller, et al.,
1973; and Richards (1954). Fortunately,
where soils are deep, and underground aqua-
fers are deep and flowing, accumulations
of salts and other pollutants may not take
place sufficiently to threaten water qual-
ity. This is made evident by many years of
irrigated agriculture located over deep
alluvium in the western states without
appreciable alteration of underground water
quality.
Artificial lakes have been success-
fully sealed in the southwestern desert
areas using natural clay soil material1.
The procedure involves lining the lake or
site boundaries with clay saturated to 25%
of its cation-holding-capacity with sodium.
The clay liner is compacted moist but not
wet at about 40% of normal field-holding
capacity. The aim is to approach maximum
possible density of compaction.
Prior to establishing artificial lake
or disposal sites, soil cores are taken to
the site depth and analyzed for clay con-
tent at 1-foot intervals. The clay laters
are plotted and stockpiled during excava-
tion for lining. If clay does not occur in
the excavation it must be brought in from
another area.
Liners for complete sealing seldom
measure less than 30 cm of clayey soil and
often approach a thickness of 60 cm if the
percentage clay is low. Both cation-
exchange-capacity and particle size distri-
bution (mechanical analysis for texture)
must be known to make liner recommendations.
The dominant clay mineral composition helps
considerably for establishment of confi-
dence limits for successful sealing.
Private communication of first author.
124
-------
CREDITS
This research was supported in part
by U.S. Environmental Protection Agency,
Solid and Hazardous Waste Research Division,
Municipal Environmental Research Laboratory,
Cincinnati, OH, from Grant No. R 803988-01
and.the University of Arizona; Agricultural
Experiment Station Paper No. 181.
REFERENCES
Alesii, B.A. and W.H. Fuller. 1976. "The
mobility of three cyanide forms in
soils." (In Hazardous Waste Research
Symposium: Residual Management by Land
Disposal), U.S. Environ. Protect. Agency,
Cincinnati, OH 45268.
Fuller, W.H. 1976. Investigation of leach-
ate pollutant attenuation in soils. U.S.
Environ. Protect. Agency. Munic.
Environ. Res. Lab. Report. Cincinnati,
OH 45268 (In press).
Fuller, W.H. 1975. Management of South-
western Desert Soils. Univ. Ariz. Press,
Tucson, AZ 85721.
Fuller, W.H. and M.F. L'Annunziata. 1968.
Movement of algae- and fungal-bound
radiostrontium as chelate complexes in
a calcareous soil. Soil Sci. 107:223-
230.
Fuller, W.H., J.E. Hardcastle, R.J.
Hannapel, and S. Bosma. 1966. Calcium-
45 and strontium-89 movement in soils
and uptake by barley plants as affected
by Ca(Ac) and Sr(Ac) treatment of the
soil. Soil Sci. 101(6):472-484.
Fuller, W.H., and Nic Korte. 1976. "Atten-
uation mechanisms of pollutants through
soils." (In Gas and Leachate from Land-
fills: Formation, Collection, and Treat-
ment. Ed. E.J. Genetelli and R.L.
Landreth). Joint Symp. Cook College,
Rutgers Univ. and U.S. EPA, Cincinnati,
OH 45268.
Gadde, R. Rao and Herbert A. Laitinen. 1974.
Studies of heavy metal adsorption by
hydrous iron and manganese oxides. Anal.
Chem. 46:2022-2026.
Garland, G.A. and D.C. Mosher. 1974. Leach-
ate effects of improper land disposal.
Waste Age 5(11) November.
Hannapel, R.J., W.H. Fuller, S. Bosma, and
J.S. Bullock. 1964a. Phosphorus movement
in a calcareous soil: I. Predominance of
organic forms of phosphorus in phos-
phorus movement. Soil Sci. 97:(5) 350-
357.
Hannapel, R.J., W.H. Fuller, and R.H. Fox.
1964b. Phosphorus movement in a calcare-
ous soil: II. Soil microbial activity
and organic phosphorus movement. Soil
Sci. 97(6):421-427.
Jenne, E.A. 1968. Controls on Mn, Fe, Co,
Ni, Cu, and Zn concentrations in soils
and water: The significant role of
hydrous Mn and Fe oxides. (In Trace
Inorganics in Water.) Advan. Chem. Ser.
73:337-387.
Korte, N.E., W.H. Fuller, E.E. Niebla,
J. Skopp, and B.A. Alesii. 1976. "Trace
element migration in soils: Desorption
of attenuated ions and effects of solu-
tion flux." (In Hazardous Waste Research
Symposium: Residual Management by Land
Disposal) U.S. EPA, Cincinnati, OH 45268.
Korte, N.E., E.E. Niebla, and W.H. Fuller.
1976. The use of carbon dioxide to sample
and preserve natural leachate. J. Water
Pollu. Control Fed. (In press).
Korte, N.E., J. Skopp, W.H. Fuller, E.E.
Niebla, and B.A. Alesii. 1976. Trace
element movement in soils: Influence
of soil physical and chemical proper-
ties. Soil Sci. (In press).
L'Annunziata, M.F. and W.H. Fuller. 1968.
The chelation and movement of Sr^9-
Sr90(y90) in a calcareous soil. Soil
Sci. 105:311-319.
Miller, D.W., F.A. DeLuca, and T.L. Tessier.
1974. Groundwater contamination in the
Northeast States. Wash. U.S. Gov't Print.
Office. June 1974.
Muller, Antony. 1973. An analysis of the
water quality problems of the Safford
Valley, Arizona Hydrology and Water
Resources Dept. Tech. Report, No. 15.
Univ. Ariz., Tucson, AZ 85721.
125
-------
Richards, L.A. 1954. Diagnosis and Improve-
ment of Saline and Alkali Soils.
USDA Agric. Handbook No. 60. U.S. Gov't.
Print. Office, Washington, DC.
Skopp, J. 1976. "Development of a computer
simulation model for predicting trace
element attenuation in soils." (In
Hazardous Waste Research Symposium:
Residual Management by Land Disposal)
U.S. EPA, Cincinnati, OH 45268.
Water Resources Associates. 1967. Flood
Control Feasibility Report, Indian
Bend Wash, Maricopa County, Arizona,
Water Resources Associates Dep't.,
Scottsdale, AZ 85251.
Weddle, Bruce and George Garland. 1974.
Dumps: A potential threat to our ground-
water supplies. Nation's Cities.
October, 1974. pp. 21-26 and 42.
126
-------
LEACHABILITY AND PHYSICAL PROPERTIES OF CHEMICALLY STABILIZED HAZARDOUS WASTES
J. L. Mahloch
Environmental Effects Laboratory
U. S. Army Engineer Waterways Experiment Station
P. 0. Box 631
Vicksburg, Mississippi 39180
ABSTRACT
The disposal of hazardous industrial waste sludges by landfilling has the potential
for an undesireable environmental impact due to leachate production and concommitant pollu-
tant migration. Chemical fixation of sludges is a viable treatment alternative which may
reduce this undesireable environmental impact. The U. S. Army Engineer Waterways Experi-
ment Station (WES), through an interagency agreement with the U. S. Environmental Protec-
tion Agency, is currently evaluating fixation technology to assess its role in sludge
disposal operations. The current program is divided into three phases involving the
characterization of the raw sludges, laboratory leaching and physical testing of raw and
fixed sludges, and pilot scale leach testing of raw and fixed sludges. The results pre-
sented within this paper will be confined to one of the five hazardous industrial waste
sludges, namely the electroplating sludge. Results of the physical testing to be presented
include bulk density, void ratio, porosity, specific gravity, and permeability. These
results have demonstrated that physical properties of the fixed products are processor
dependent and vary in quality. The results of the leaching tests show that all fixed
materials are leaching pollutants to some degree. Comparison between the leaching data
for the raw and fixed sludges demonstrates that leaching properties are dependent on the
pollutant analyzed. Based on the results presented in this paper, fixation appears to be
a viable alternative for reducing adverse environmental impact of sludge disposal.
INTRODUCTION
The disposal of wastes to land may re-
sult in an adverse environmental impact,
particularly if these wastes contain hazar-
dous materials. Interaction of wastes and
physical, chemical, and biological mecha-
nisms may permit the environmental trans-
port of hazardous pollutants at unaccept-
able rates. To avoid this adverse envir-
onmental impact, a treatment of these wastes
may be required prior to disposal.
Waste material which may be classified
as being potentially hazardous include
sludges or residues arising from industrial
wastewater treatment processes. These
treatment processes are specifically de-
signed to remove toxic pollutants from
water, and concentrate them in a solid
residue or sludge. Land disposal of such
residues may result in release of these
pollutants to the surrounding ecosystem.
The most prevalent pathway for this migra-
tion is through an aqueous medium. To
retard the movement of pollutants from
residues, several concepts may be applied
during or prior to disposal. Creation of a
barrier between the environment and waste
material by lining disposal sites is one
option. Investigation of disposal site
characteristics to assess its ability to
prevent pollutant migration constitutes
another option. Alternately, the waste may
be treated by a process designed to convert
it into a product in which pollutant mobil-
ity is retarded. This latter concept may
be termed chemical fixation if it takes
place by chemically altering the waste
material.
127
-------
Chemical fixation is a process which
generally produces a material in which the
waste is contained within an inert matrix.
Additionally, the fixation process may
chemically alter the state of the pollu-
tants within the waste material to reduce
their mobility. To successfully apply
chemical fixation in the treatment of
industrial sludges or residues, the pro-
cess must be evaluated to insure that it
will work in the fashion for which it is
designed. Since sludges are generally
very heterogeneous mixtures of materials,
evaluation must of necessity be on re-
stricted categories of sludges. Evalua-
tion should include assessment of physical
and chemical properties with respect to
stability.
The most direct test of chemical
stability is a leaching test. The leaching
test must be executed in such a fashion as
to realistically simulate the potential
environmental migration of pollutants from
the fixed material. Physical properties
of the fixed material are important to the
extent that they affect leaching proper-
ties; therefore, the results of physical
and chemical testing must be integrated
to assess the merits of fixation.
The U. S..Army Engineer Waterways
Experiment Station, through an interagency
agreement with the U. S. Environmental
Protection Agency, has embarked upon a
program to evaluate the chemical fixation
of sludges. Within the current program
ten sludges are being tested in combi-
nation with seven fixation processes.
This paper will present preliminary data
for one of the industrial waste sludges.
METHODS
Materials
The sludge under study originated
from an electroplating industry as a pro-
duct of wastewater treatment. The sludge
is currently disposed by ponding and
samples were obtained from the present
disposal site. This material contains
approximately 39 percent solids and the
major pollutants are the metals. The
principle metals of interest in the sludge
are chromium, nickel, copper, zinc, and
cadmium. Calcium is also present in large
amounts as a result of treatment processes
utilized. This raw sludge will be desig-
nated as R-200 for the remainder of this
paper. Samples of the sludge were fixed
by three commercially available fixation
processes and will be designated A-200,
B-200, and C-200 respectively.
Physical Testing
Physical tests performed on specimens
of raw and fixed sludge included determi-
nation of bulk density, void ratio, poros-
ity, specific gravity, and permeability.
With the exception of permeability, all
tests were performed in accordance with
American Society for Testing and Materials
(ASTM) procedures (1). Permeabilities
were determined by use of a falling head
permeameter for the raw sludges and by
use of a triaxial testing machine for the
fixed sludges.
Chemical Analysis
Leach Testing
Leach testing was performed on the
raw and fixed sludges. The procedures
and experimental conditions for the leach
testing have been documented elsewhere
(2,3). All leach testing was conducted in
triplicate, and blank columns were used
for controls. Two leaching solutions of
different pH, 4.7 and 7.5, were employed.
Elutriate Test
The elutriate test as modified (4)
was utilized as a rapid leach test and
involved the following procedures:
(a) Prepare a 1:4 (V/V or W/V)
mixture of material and water
at pH 4.7
(b) Mix on a wrist action shaker for
one hour
(c) Centrifuge at 2500 rpm for
30 minutes
(d) Filter centrifugate using a
0.45y filter
(e) Analyze filtrate for desired
constituents.
128
-------
Total Analysis of Specimens
A total analysis of raw and fixed
sludge specimens was determined by di-
gesting a sample in a mixture of hydro-
fluoric and nitric acid. The resultant
digest was analyzed for the desired metals.
RESULTS
Physical Properties
The results of the physical proper-
ties tests are presented in Table 1.
TABLE i
PHYSICAL PROPERTIES OF RAW AND FIXED SLUDGES
SAMPLE ID
R-2H
A-ZOO
B-200
C-200
In general, the bulk density is increased
for fixed sludges, and the void ratio,
porosity, specific gravity, and permea-
bility are reduced. For samples B-200 and
C-200, the permeabilities are increased
after fixation. In the case of B-200 this
may be explained by noting that process B
results in a fixed material physically
resembling a soil.
Chemical Properties
Results of the total digest for the
raw sludges and fixed products are pre-
sented in Table 2. Note that in most
TABLE 2
RESULTS OF TOTAL DIGESTS
BULK DENSITY
(LB/CF)
63.5
100.4
17.1
75.4
VOID
RATIO
3.115
1.209
3.162
1.251
POROSITY
(»
79.2
54.7
76.0
55.6
SPECIFIC
GRAVITY
3.27
2.65
2.94
1.81
PERMEABILITY
(CH/SEC)
1.3x10-'
4.1 «UT'
1.2«10-s
LI « «r<
METAL CONCENTRATION (%)
Ca
3.06
2.63
4.63
Cd
0.069
0.041
0.025
0.010
JiL
5.78
4.65
1.83
1.42
Cu_
3.65
3.02
0.96
0.68
M_
0.23
0.19
0.09
0.05
Zn
0.68
0.55
0.20
0.14
SAMPLE ID
R-200
A-200
B-200
C-200
cases concentration of metals are reduced
by fixation. The only exception to this
is in the case of calcium for sample A-200;
this is probably the result of calcium
being present in the fixation additive.
Decreasing concentrations of metals for
the fixed sludges is advantageous since it
is tantamount to a mass dilution effect.
The results of the leaching tests are
presented by the type of pollutant con-
sidered. The mean results for the control
columns are presented for all leaching
results. This method has the dual advan-
tage of establishing background concen-
trations to assess the true value of
leaching and also to present an overall
summary for the quality of the experimental
design. The leaching results presented in
this paper apply only to the acidic leaching
solution. A comparison between leaching
solutions will be made subsequently in this
paper.
Specific conductivity, which is pro-
portional to dissolved solids, is presented
in Figure 1. The raw sludge is
150.00O
100,000 -
10,000 J|
1,000
100
O- -O RAW SLUDGE
A PROCESS A
A PROCESS 8
• PROCESS C
40
80 120 ISO
ELAPSED TIME, DAYS
200
240
Figure 1. Leaching Results, Conductivity.
129
-------
characterized by a relatively constant
leach rate, while the fixed materials
demonstrate a reducing leach rate as a
function of time. The background level is
low, demonstrating a good blank and leach-
ing of pollutants from all specimens.
The leaching curves for sulfate and
chloride are presented in Figures 2 and
3, respectively. These anions represent
SOfBO
10,000 j
0 -O RAW SLUDGE
A PROCESS A
A PROCESS B
• PROCESS C
40
80 120 180
ELAPSED TIME, DAYS
200
240
Figure 2. Leaching Results, Sulfate
pollutants which are ubiquitously present
in most sludges. These leaching curves
demonstrate a constant rate for the raw
sludges and decreasing rates for the fixed
materials. In all cases the fixed sludges
are leaching at lower rates than the raw
sludges. For chloride, the leachates from
the fixed columns converge to the blank
level quickly, indicating that chloride is
rapidly eluted from these specimens. In
the case of sulfates the leach rates for
the fixed specimens are declining but the
leachates continue to contain significant
concentrations of sulfates.
100,000
O- O RAW SLUDGE
A PROCESS A
A PROCESS B
• PROCESS C
80 120 160 200
ELAPSED TIME, DAYS
240 280
Figure 3. Leaching Results, Chloride
The leaching curves for the metals;
calcium, cadmium, chromium, copper, nickel
and zinc are presented in Figures 4 through
9, respectively. The leaching curves of
calcium demonstrate that the raw and fixed
sludges are leaching equally. There
appears to be no decline for calcium with-
in the time frame of the data plotted.
Calcium is present in large concentrations,
Table 2, for all specimens tested. It is
presumably being leached at a solubility
limited rate and the columns will prob-
ably continue to exhibit equivalent leach
rates until the available calcium becomes
limited. For cadmium, nickel, and zinc,
Figures 5, 8, and 9, the leaching proper-
ties for the specimens appear to be simi-
lar. In all cases one of the fixed
specimens demonstrates a significantly
higher leach rate for these metals than
the raw sludge. In the case of cadmium
and zinc the raw sludge and the remainder
of the fixed specimens demonstrate rapidly
decreasing leachate concentrations. For
130
-------
nlcKel trie leacnate rrom cne raw s
appears to be relatively constant. The
leaching curves for chromium and copper,
Figures 6 and 7, appear to be similar with
the leachate concentrations for the fixed
sludges being equal to or greater than
the raw sludges. This fact is particular-
ly noticeable in the case of chromium.
For the raw sludges the leach rates appear
to be relatively stable while those of the
fixed sludges are decreasing as a function
of time.
10,000
10
1.0
0.1
LEGEND
O- -O RAW SLUDGE
A PROCESS A
A PROCESS B
• PROCESS C
100
10
i 1-0
0.1 OCt
0.01
0.001
LEGEND
O- -O RAW SLUDGE
A PROCESS A
A PROCESS B
• PROCESS C
40
60 120 1BO ZOO 240 280
ELAPSED TIME, DAYS
40 80 120 180 200 240 280
ELAPSED TIME, DAYS
Figure 4. Leaching Results, Calcium.
Figure 5. Leaching Results, Cadmium.
131
-------
10000 cr
100
10
1.0
0.1
0.01
O.OOI
I '
LEGEND
O O RAW SLUDGE
A PROCESS A
A PROCESS B
• PROCESS C
'BLANK;
/ / / /
40 8O 120 160 200 240 28O
ELAPSED TIME, DAYS
O 40
60 120 160 ZOO
ELAPSED TIME, DAYS
240
Figure 6. Leaching Results, Chromium
Figure 7. Leaching Results, Copper
132
-------
100
10
Q.
0.
i
O.I
0.01
0.001
7
LEGEND
O- -O RAW SLUDGE
A PROCESS A
A PROCESS B
• PROCESS C
\
O
40 eo 120 ieo 200 240 2ao
ELAPSED TIME, DAVS
1000
100
10
a.
a.
10
0.1
0.01
LEGEND
O 0 RAW SLUDGE
A PROCESS B
• PROCESS C
40
80 120 160 200 240
ELAPSED TIME. DAYS
280
Figure 8, Leaching Results, Nickel.
Figure 9. Leaching Results, Zinc.
DISCUSSION OF RESULTS
The leaching of pollutants from the
specimens tested in this experiment appears
to be a function of the physical and chem-
ical mechanisms operative on these speci-
mens. The effect of any biological mech-
anism on pollutant mobility is probably
insignificant due to the low organic
content of these materials. It is apparent
from the data presented that the physical
and chemical mechanisms are interactive.
133
-------
The results of fixation are generally
manifested by a consolidation or cementing
of the sludges into a definite shape. This
fact is confirmed by the decreasing poros-
ity, void ratio, and increasing bulk den-
sity of the fixed materials. This apparent
alteration of physical geometry changes
the principle mechanism for mobility of
pollutants between the raw and fixed
sludges. For the raw sludges the principle
mechanism must be assumed to be solubili-
zation of the pollutants from the sludge
solids to the aqueous medium. In the case
of the fixed sludges, the migration mecha-
nism is solubilization coupled with diffu-
sion of pollutants to the surface of the
fixed materials. It is assumed that the
diffusion step is the rate limiting event
for this mechanism.
The operation of these mechanisms may
in part be confirmed by observing the com-
parative leach behavior of the raw and
fixed specimens. The raw sludge is char-
acterized by stable leach rates for most
pollutants indicating a solubilization
proportional to the concentrations of
pollutants present. Those pollutants
demonstrating a decreasing leach rate for
the raw sludge would indicate a chemical
interaction decreasing the solubilities
of these consitituents, or a decrease in
pollutant available for elution. The
fixed sludges demonstrate a decreased
leach rate as compared to the raw sludge,
particularly for the more mobile species,
chloride and sulfate. This fact would
tend to indicate that diffusion, and not
solubility, was the rate limiting step,
confirming the mechanism proposed previ-
ously. Calcium behaves in a similar
fashion except that the solubility step
has not depleted the available calcium
allowing a diffusion mechanism to become
dominant. For the remaining metals it
must be assumed that similar mechanisms
are operative, although for process C it
appears that something is stimulating
metal mobility. Chromium appears to be
operating in a like manner, but the fixa-
tion process appears to have increased the
solubility of this metal.
An additional factor which must be
considered is the effect of permeability
on sample leaching. The experimental
design for the fixed specimens utilizes a
surrounding solid medium which is
relatively permeable compared to the fixed
specimens, except for the B. sample. In
this case the operation of a diffusion
mechanism is almost guaranteed by the
column hydrodynamics. For B-200 this is
not as evident since the material occupies
the entire cross sectional area of the
leaching column; however, this sample did
alter the physical configuration of the
sludge and the diffusion mechanism may be
assumed to be operative in a limited sense.
The comparison of leaching data in
terms of concentrations does have the ad-
vantage of allowing a ready interpretation
of possible environmental impact for the
experimental design employed. Interpreta-
tion of the leaching data, in terms of mass
of pollutant mobilized has the advantage of
presenting a more quantitative picture of
the results. An additional tool which may
be employed is to calculate apparent diffu-
sion rates for the specimens tested. These
rates may be calculated from the following
equation (5):
Za
n V^
A S
o
l/2tl/2
Where:
A
mass of pollutant leached in
n periods
initial mass of pollutant
present in the specimen
V = specimen volume
S = specimen surface area
(effective)
D = effective diffusion rate
t = leachate renewal time
The results of these calculations are
presented in Table 3 for copper during
four leaching periods. Figure 10 contains
the plots of the leaching data for copper
in the format of the above equation. The
plots in Figure 10 demonstrate the
following concepts:
(a) Data between fixed replicates
appear to be very precise except
134
-------
for the case of process C, and
for this process the slopes are
comparable.
(b) The data for the raw sludges do
not conform well to this plotting
format, indicating a lack of a
diffusion mechanism.
TABLE 3
SUMMARY OF LEACHING RESULTS. COPPER
TREATMENT
RAi
A
TOTAL MASS
LEACHED (m|)
2.5
21.0
91.0
45S3.0
MEAN LEACHATE
CONC (fflf/r)
2.47
2.03
5.46
415.00
EFFECTIVE DE
(cmVDAV)
1.28 » 10-"
L25"10-'
2.29 "W"
2.78 * 10 -'
2.10
0.23
0.94
152.00
Table 3 also contains the results from
the elutriate tests and the mean concen-
tration of copper leached during the noted
time frame. It is apparent that little or
no comparison is possible between leachate
data for the raw and fixed sludges for the
parameters utilized. Between the fixed
sludges a very good correlation may be
obtained for all parameters. The only
conflict appears to be for the effective
diffusion rates for process A and B.
LEGEND
O A-200
A B-20O
V C-200
D R-200
This may be explained in part by noting
that the volume to surface ratio is very
influential on the outcome of the diffu-
sion rate calculated. For sample B-200
there is no adequate method for easily
determining this ratio and a value was
assumed for these calculations; therefore,
the value for De may be in error. The
values for De for process A and B fall
within acceptable values (5).
The results of the elutriate test
for all metals plus pH and conductivity
are presented in Table 4. These values
TABLE 4
RESULTS OF ELUTRIATE TEST
MASS OF POLLUTANT ELUTED (mi)
SAMPLE ID
R
A
B
C
•200
-200
•200
•200
PH
7.2
6.4
6.8
5.1
CONDUCTIVITY
3.0
3.0
4.5
5.7
*10J
*10J
«10>
»10>
Cl
348
358
323
302
Cd
0.05
0.03
0.06
3.30
Cu
2.10
0.23
0.94
152.00
Nl
0.51
0.05
0.05
17.90
Zn
0.96
0.04
0.04
40.60
Cr
0.09
0.53
5.40
3.60
Figure 10. Diffusion Plot, Copper
correlate well with the results of the
leaching data presented earlier. This
fact would seem to indicate that the
elutriate test or some modification of it
may prove to be a reliable indicator
procedure for assessing the leaching of
raw and fixed sludges.
To obtain an overall assessment of
the leaching data from the columns, a
procedure known as discriminant analysis
was employed (6,7). Discriminant analysis
allows the comparison of multivariate
populations on a reduced dimensional plane
by the construction of a functional rela-
tionship between the variables and the
reduced space. If the "discriminant"
functions are well correlated to the
original variable set, then the data may
be interpreted graphically. To apply this
procedure the leaching variables plotted,
(Figures 1-9) plus pH were subjected to
discriminant analysis. The data set
included the first four leaching periods,
the results from both leachjing solutions,
and all control column results. The
results of the discriminant analysis are
shown in Figure 11 as a plot of the data
sets for the first two discriminant
functions (accounting for 85 percent of
the data variance).
135
-------
70
30.
B-20C
B-2«
b|
°" . R-ZOOo.
»R-ZOOb
A-ZOOa •
A-ZOOb •
1
C-4.
C-3»«c
•
1
2
C-l
-
C-200b
30
Figure 11.
50 6O 70
DISCRIMINANT FUNCTION-I
Leaching Results, Discriminant
Plot,
An examination of Figure 11 demon-
strates that little difference exists for
the results in terms of leaching solutions
applied. This was somewhat expected from
prior knowledge regarding properties of
these sludges and was confirmed by this
analysis. This result would presumably
justify elimination of applied pH from
consideration as one of the major vari-
ables affecting leachate quality. To
gain a greater insight to the meaning of
this plot, an examination of the corre-
lation of the discriminant functions with
the original variable space is required.
The first discriminant function is
inversely related to leachate pH and
directly related to chromium, nickel, zinc,
copper, and cadmium concentrations. The
second discriminant function is directly
related to conductivity, sulfate, chloride,
and calcium. These relationships have
meaning of their own merit; the first
discriminant function indicating a close,
inverse correlation between heavy metals
and pH and the second indicating a direct
correlation between conductivity and
the anions plus calcium. The plots are
made relative to a value of 50 for each
discriminant function, thus the distance
for the centroid of the plot is propor-
tional to the deviation from, the grand
mean for that sample.
Examining Figure 11, it is observed
that the control columns occupy the lower
left quadrant indicating a negative (lesser)
deviation from the overall leaching data.
The fixed samples for process C occupy the
middle right quadrant indicating a high
leaching of metals, but average leaching
rates for the remaining pollutants. The
raw sludges and those samples fixed by
processes A and B occupy the upper left
quadrant indicating comparable leachate
quality. In general, the results of this
analysis may be confirmed by an examina-
tion of the leachate data presented previ-
ously; however, this comparison is between
those data sets included in the analysis
and may tend to bias the results.
A realistic assessment relating to
the environmental effects of a fixed
sludge must, of necessity, include some
consideration of scaling parameters
associated with field disposal. This
assessment is related to the diffusion
mechanism which is presumably operating
for fixed materials and the exposed sur-
face area at a disposal site. To make a
preliminary evaluation of this concept the
data for copper from R-200, A-200, and
B-200 during the first four leaching
periods and both leaching solutions were
examined. For the case of a diffusion
mechanism, the leachate quality is a
function of the initial mass of pollutant
(i.e., copper) present in the specimen.
Figure 12 is a plot of mass of copper
leached versus percent copper present in
the specimen. A regression analysis of
the data demonstrated no dependence be-
tween copper present in the sample and
the leachate copper mass for the raw
sludge. If the previously proposed
mechanism is correct, then this should be
observed, as it was. Conversely, for the
fixed specimens a significant dependence
was demonstrated between copper initially
present in the specimen and mass leached.
This fact tends to confirm the diffusion
mechanism previously alluded to in this
paper.
To apply these results to a field
condition it is necessary to correct the
data for the fixed samples in Figure 12
136
-------
100
90
80
2
Q" 70
UJ
5 60
0 50
O
fe
v> 40
30
20
10
n
1
£
^
/
/
/
•
«
I1
/
/
/
i
X
'
-n-
1
/
c
4
/
LEC
) RAW
> FIXE
-------
CONCLUSIONS
As a result of the data obtained from
the study on raw and fixed electroplating
waste treatment sludges, the following
conclusions may be made:
(a) Chemical fixation of sludges is
manifested by physical and
chemical alterations of the par-
ent material. As a result of
these alterations the mechanisms
for leaching and its associated
environmental impact are altered.
(b) The effect of the pH of leaching
solutions applied to specimens
in this study was insignificant
in the pH of the leachates. The
effect of this variable, within
a reasonable range of values,
may be considered minimal.
(c) The relation of laboratory data
obtained in this study to field
disposal conditions is an inte-
gral phase of fixation assess-
ment. An evaluation conducted
in this paper demonstrated that
fixation is a viable alternative
for reducing pollutant migration
from sludges.
(d) The modified elutriate test
appears to offer a satisfactory
method for rapid evaluation of
the leaching of raw and fixed
sludges, although the data are
not interchangeable.
It should be stressed that these
conclusions reflect a limited analysis
of the data obtained from the present
study. An individual consideration of
all major pollutants is necessary to
completely describe the potential
environmental impact associated with
sludge disposal. Furthermore, the
assumptions related to field scale
disposal operations must be validated
and related to the laboratory tests.
REFERENCES
1. Annual Book of ASTM Standards, Parts
11 and 12, American Society for
Testing and Materials, Philadelphia,
PA, 1973.
2, Mahloch, J. L,, and D. E. Averett,
"Pollutant Potential of Raw and
Chemically Fixed Hazardous Industrial
Wastes and Flue Gas Desulfurization
Sludges," Unpublished Interim Report,
January, 1975.
3. Landreth, R. E. and J. L. Mahloch,
"Stabilization of Hazardous Wastes
and SOX Sludges," Proceedings of the
National Conference on Management and
Disposal of Residues from the Treat-
ment of Industrial Wastewaters,
February 3-5, 1975, Washington, D. C.
4, Keeley, J. W. and R. M. Engler,
"Discussion of Regulatory Criteria for
Ocean Disposal of Dredged Materials:
Elutriate Test Rationale and Imple-
mentation of Guidelines," Paper
D-74-14, U. S. Army Engineer Waterways
Experiment Station, Vicksburg, MS,
1974.
5. Godbee, H. W. and D. S. Joy,
"Assessment of the Loss of Radioactive
Isotopes from Waste Solids to the
Environment, Part I: Background and
Theory," Oak Ridge National Laboratory,
Report No. ORNL-TM-4333, Oak Ridge, TN,
1974.
6. Cooley, W. W. and P. R. Lohnes,
Multivariate Data Analysis, John
Wiley and Sons, New York, NY, 1971.
7. Mahloch, J. L., "Graphical Interpre-
tation of Water Quality Data," Water,
Air, and Soil Pollution, 3: 217-236,
1974.
138
-------
A POLYMERIC CEMENTING AND ENCAPSULATING PROCESS FOR MANAGING HAZARDOUS WASTE
C. C. Wiles* and H. R. Lubowitzt
*U.S. Environmental Protection Agency
26 W. St. Clair Street
Cincinnati, Ohio 45268
tTRW Systems Group
One Space Park
Redondo Beach, California 90278
ABSTRACT
A process using polymeric materials to cement and encapsulate dry hazardous waste was
researched, developed, and evaluated. The process involves cementing particulates of
waste into 500 to 1000 pound agglomerates, and then fusing a plastic jacket onto the
agglomerate surfaces, thereby encapsulating them. Polybutadiene, as a binder resin, was
found to be capable of cementing waste 94 to 96 percent by weight of the agglomerate. The
binder exhibits properties that contribute to ready processing of the agglomerates. En-
capsulating the waste-binder agglomerates with 1/4-inch jacket of high density polyethyl-
ene can be carried out by packing powdered polyethylene about the agglomerate and then
fusing the powder in situ. The method was satisfactorily applied to produce laboratory
specimens containing, in some cases, high concentrations of highly water soluble heavy
metal wastes, e.g., sodium metaarsenate. Test specimens were subjected to leaching so-
lutions for 120 days and mechanical stresses to evaluate the processes' capability to
isolate the hazardous waste from selected disposal environments. Results indicate the
processes' ability to prevent, or limit to acceptable levels, the release or de-
localization of the hazardous waste to the environment under various disposal schemes.
This paper discusses the process and provides results of the evaluations.
INTRODUCTION
Under Section 212 of the Resource
Recovery Act of 1970, the Environmental
Protection Agency became responsible for
the preparation of a Report to Congress
defining the various aspects of the hazard-
ous waste problem (1,2). The report was
based on specific contract efforts designed
and programmed to provide the information
and insight necessary to the presentation
of a complete and accurate picture. One
contract identified a number of hazardous
materials, their sources and quantities,
and the technology utilized for their
treatment. Another contract had three con-
current objectives: (1) to refine the
listing of hazardous wastes based on
further information, (2) to analyze and
assess current hazardous waste disposal
technology, and (3) to define research and
development necessary to provide infor-
mation or adequate technology (3).
The quantity of industrial and munici-
pal wastes generated in the United States
is increasing faster than the population.
The diversity of these wastes preclude the
utilization of a single method or technology
to provide adequate treatment and/or
disposal. As a result, a number of method-
ologies and technologies are in use, or
have evolved and are under development (4).
In addition, recycling and utilization of
wastes are being examined as techniques to
limit the quantity of waste which must be
139
-------
provided ultimate disposal. Although this
alternative is attractive, only limited
success is being claimed. Also, reality
must be faced; technologies are not likely
to emerge which will detoxify all com-
ponents of hazardous wastes. There will
most likely always be some form of toxic
residuals (wastes) which must undergo
ultimate disposal.
Of particular concern are those wastes
with the potential to harm man and/or the
environment. The hazardous wastes may be
either in the solid state or mixed with a
liquid, most often water, in the form of
sludges, slurries or slimes. Almost any
branch of modern industry, metallurgical,
chemical, ceramic, mineral, food processing,
metal treatment, petroleum refining,
treatment of municipal sewage, etc., gener-
ates some kind of wastes; described vary-
ingly as tailings, scraps, rubble, garbage,
refuse, residue, sludge, slime, slurry, mud,
etc. These wastes often contain toxic
compounds including arsenic, lead, mercury,
selenium, beryllium, cadmium, zinc, and
chromium. The potential hazard is increas-
ing rapidly due to the greater quantities
of concentrated toxic solids and sludges
being produced by control policies and
equipment designed to limit air and water
pollution.
One recommendation of the hazardous
waste studies led to the implementation of
additional research to more fully investi-
gate "fixation" as a solution to the
problem of providing acceptable disposal of
hazardous wastes. In July 1973, SHWRD
awarded a research contract to TRW, Inc. to
expand proof-of-principle and feasibility
testing of two processes for passifying
toxic waste. One process utilized polymeric
materials to form, contain, and isolate
toxic solids; while the other process
relied upon inorganic materials. The ulti-
mate objective of the research and develop-
ment was to provide a process capable of
localizing and limiting the release to the
natural environment of toxic waste materials
to levels consistent with control strate-
gies and with both short term and long term
protection of the environment. Most im-
portant were hazardous wastes that could
not be adequately localized by available
techniques.
The initial phase of the research pro-
gram was designed to determine information
on three important process characteristics:
(1) the technical behavior of the processes;
(2) the ability of the processes to passi-
vate (localize) hazardous wastes; and (3)
the process economics. Waste simulants were
used to ease the handling problems and to
insure a known baseline for the process
development and evaluation. A number of
different organic and inorganic cements and
jacketing materials were tried in various
proportions. The effectiveness of the
processes to isolate the wastes was de-
termined on the basis of results of leach
tests using various solutions in which
passivated waste blocks were immersed. Pre-
liminary design and economic analysis were
also determined for both the organic and
inorganic cementation processes.
Results of the first year's work are
available and describe results of tests on
both the "organic" and the "inorganic"
process.* Although promising, the process
utilizing inorganic materials was judged as
not sufficiently unique in its approach to
warrant additional EPA support. Addition-
ally, the process did not appear to be
suited to the adequate control of "extremely"
hard to manage hazardous waste, such as
arsenicals, for which other available
processes were judged not adequate.
Therefore, SHWRD directed TRW to cease work
on the inorganic process and to concentrate
their efforts on additional research de-
velopment, and evaluation of the "organic"
(polymeric) process.
Based upon results of the initial
studies high performance resins were se-
lected for the waste-binder agglomerization
and for the jacketing (encapsulation). The
additional studies concentrated on the
following: (1) to show general applicability
of the selected resins to passify hazardous
waste regardless of their chemical compo-
sitions, (2) to provide an encapsulation
process suitable for large scale operations,
(3) to evaluate and demonstrate, if possible,
the performance characteristics of the
process when subjected to harsh environ-
mental stresses and, (4) to provide initial
process designs and economic information.
*Contracts 68-03-0089 and 68-03-2037, Solid
and Hazardous Waste Research Division, U.S.
Environmental Protection Agency, Cincinnati,
Ohio 45268.
140
-------
The purpose of this paper is to de-
scribe the "organic" or polymeric process.
Details of process description, process
development and evaluation, process appli-
cability, limited economics, and additional
information will be presented.
PROCESS DESCRIPTION
The polymeric process used to passify
the selected hazardous waste involves the
following basic steps (Figure 1):
o dewatering of sludges
o coating the waste particulate with
the resin
o evaporating the solvent carrier
o agglomerating the waste particulate—
resin
o compacting by thermo-setting to form
a waste-binder block, and,
o encapsulating the waste-binder block
(jacketing).
Resin•
Waste
Jacket
Resin
Encapsulated
Waste
Figure 1. Schematic of the Polymeric
Process for Stabilizing Waste
Resins selected for forming the waste-
binder agglomerate and the jacket were
modified polybutadiene and polyethylene
respectively. This selection was based
upon results of the earlier study on resin
screening and the following criteria:
o High loading ability, i.e., small
amounts of resin must be capable of
agglomerating and cementing large
amounts of waste particulates.
o Chemical stability of the agglomerate
waste.
o Ability to readily wet solid waste
particulate.
o Easy and rapid formation of resin
coated waste agglomerate for a wide
variety of waste materials.
o Uniform distribution of resin in
the agglomerate.
o High heat distortion temperature
(HOT) to allow for wide selection
of resin for jacketing; fusion of
coating resin to the cemented waste
core should not cause any dimension-
al distortion of the compacted core
block.
o Low cost.
o Stability under normal conditions:
no special precautions for resin
storage.
o Satisfactory fluidity of waste/resin
agglomerate particulate for fast and
thorough filling of mold for com-
pacting by thermosetting.
o Long "pot life1' to allow the
processing time to vary widely.
Because of flexibility in their formu-
lation, hydrocarbon resin systems in gener-
al are excellent candidates for passifying,
by agglomeration and encapsulation, heavy
metal compounds. However, certain stereo-
configurations of polybutadienes were
found to be particularly applicable for
forming an agglomerate of waste and binder.
Those selected are liquid and polymerize
easily because of the high content of un-
saturated bonds.
The polybutadiene and polyethylene
resins in combination were found to yield
high performance, passivated waste products.
This assessment could not be applied dis-
tinctly to other resin systems; consequently,
the polybutadiene-polyethylene resin system
appears unique for passifying wastes by
agglomeration and encapsulation. Included
in the assessment were product processing
techniques. Technological barriers to
ready reproducible processing of encapsu-
lated wastes are markedly reduced by the
physical and chemical character of these
resins.
Prior to agglomerating 4 percent w/w
polybutadiene resin coated particulated
wastes, it was considered important to
141
-------
observe the free flowing character of the
particulates and their shelf stability.
Free flowing particulates facilitate load-
ing of large molds for subsequent thermal
fusion of particulates into large agglomer-
ates. The property of shelf stability
places essentially no time constraints upon
initiating fusion operations. These advan-
tages contribute to ease of making passi-
vated products. The product performance
is consequently less sensitive to the
mechanics of product fabrication. All resin
coated particulates freely flowed and
agglomerated readily (Figures 2, 3, 4, and
5).
Figure 4. Polybutadiene Coated Residue
of Sludge 700
Figure 2. Polybutadiene Coated Residue
of Sludge 200
Figure 5. Fused Residue of Sludge 700
Figure 3. Fused Residue of Sludge 200
142
-------
Method of Waste Agglomerating and Encapsu-
lating
A pictorial sequence of the laboratory
procedure employed for fabricating encapsu-
lated heavy metal wastes is provided. The
free flowing resin coated particulates are
placed into a mold (Figure 6).
Figure 7. Hazardous Waste Agglomerate
Positioned for Resin Jacketing
Figure 6. Agglomerated Hazardous Waste
Residue Emerging from Mold
Agglomeration of the particulates
placed under moderate mechanical pressures
occurs in the temperature range of 250 to
400°F at various time intervals after the
resin coating operation. Here demon-
strations were sought which showed different
wastes readily agglomerating over a wide
temperature range from free flowing resin
coated waste particulates stored at various
time intervals.
Next the agglomerates are coated with
powered polyethylene (Figures 1, 8, 9, and
10).
Figure 8. Agglomerate Submerged in
Powdered Polyethylene
143
-------
Figure 9. Non-Jacketed Side Seen on the
Free-Standlng Agglomerate After the First
Jacketing Step
Figure 11. Encapsulated Agglomerate Seen
After Final Resin Jacketing Step
Figure 10. Non-Jacketed Side of Agglom-
erate Seen Positioned for Final-Resin
Jacketing
Inspections of the encapsulated waste-
binder agglomerates showed that the jackets
adhered intimately and tenaciously to the
agglomerates (Figures 11, 12, and 13).
Figure 12. View of Cross Section of
Encapsulated Hazardous Waste
144
-------
Figure 13. Cross View of Encapsulated
Arsenic Containing Waste
WASTE IDENTIFICATION
Wastes available for evaluating the
polymeric process consisted of ten sludges
(Table 1). These sludges were made
available from a study being conducted for
SHWRD by the U.S. Army Corps of Engineers,
Waterways Experimental Station, Vicksburg,
Mississippi.*
Another waste from the pesticide
manufacturing industry became available
during the study and was included. The
waste contained 1-1/2 percent (by weight)
monosodium methane-arsenate, 49 percent
sodium chloride and 49 percent sodium
sulfate (Figure 13).
Selection of Waste
The wastes selected were those desig-
nated in Table 1 as 200, 300, 500, 700, and
900. These materials differ significantly
in chemical composition and material con-
sistency. Furthermore, they represent a
broad spectrum of sources in the chemical
industry, each source issuing significant
quantities of waste. A blend of equal parts
by weight of 200, 300, 500, 700, 800, and
900 were encapsulated for detailed leaching
and mechanical property studies. The blend
contained the following atoms: Cu, Cr, Zn,
Ni, Cd, Na, Ca, Fe, Hg.
The waste with monosodium methane-
arsonate was also selected for evaluating
the encapsulation process. The arsenic
contaminant, existing as a sodium salt in
a mixture of sodium salt compounds, is
expected to be very water soluble. As such,
test specimens from this material were
judged to provide an excellent measure of
the ability of the encapsulation method to
isolate such wastes.
TABLE 1. WASTES AVAILABLE FOR PROCESS EVALUATIONS
Code No.
100
200
300
400
500
600
700
800
900
1000
Source
SOX scrubber sludge, lime process, eastern
coal
Electroplating sludge
Nickel - Cadmium battery production sludge
SOX scrubber sludge, limestone process,
eastern coal
SOX scrubber sludge, double alkali process,
eastern coal
SOX scrubber sludge, limestone process,
western coal
Pigment production sludge
Chlorine production brine sludge
Calcium fluoride sludge
SOX scrubber sludge, double alkali process,
western coal
Major Contaminants
Ca,
Cu,
Ni,
Cu,
Na,
Ca,
Cr,
Na,
Ca,
Cu,
S04~
Cr,
Cd
so4~
Ca,
S04=
Fe,
ci-,
F~
Na,
/so3~
Zn
/so3=
S04~/S03=
/so3=
CN
Hg
so4=/so3=
*Interagency Agreement D40569, EEL-WES.
SWRD, Environmental Protection Agency,
Cincinnati, Ohio 45268.
145
-------
Waste Characterization
Five gallon quantities of aqueous
sludges 200, 300, 500, 700, 800, and 900
were dewatered by exposure to the atmos-
phere to a consistency that exhibited no
mobile water. The resulting residues were
then heated in an oven at 300°F for about
1/2 hour. The residues thereafter granu-
lated readily with mechanical stirring. A
uniform consistency, absent of gross aggre-
gates, was sought in particulation. No
attempt was made to obtain a particular
particle grind because various material
consistencies were desired for agglomer-
ation and encapsulation. Demonstrating
successful passivation would indicate that
it is not necessary to reduce wastes with
different particulation characteristics to
a specific grind, nor is it necessary to
reduce a given waste repeatedly to the
same grind. In some cases, mechanical
stirring was not necessary. Residues of
sludges 500 and 900 did not require stirring
to obtain uniform material consistencies
suitable for encapsulation.
The residues of sludges 200 and 700
appeared as agglomerated fines (Figures 14
and 15). The average dimensions of the
agglomerates ranged between 5 to 15 mils.
The monosodium methanearsonate containing
waste appeared as grey-white in color and
exhibited the consistency of sugar. It was
processed as received without pretreatment.
Figure 14. Waste 200 Residue (Electro-
plating Sludge) Magnification 100X, Scale
Division 0.5 Mil
Figure 15. Waste 700 Residue (Pigment Pro-
duction Sludge) Magnification 100X, Scale
Division 0.5 Mil
PROCESS EVALUATION
Since the process was expected to
provide adequate protection from toxic
waste entering the environment, investi-
gations included evaluation of the per-
formance characteristics of the coated
blocks of waste and polymers under various
simulated environmental stresses. Although
these tests were to be performed in the
laboratory only, they were designed to
provide indications of how well the coated
waste-binder agglomerates would be expected
to perform under actual disposal conditions
such as the landfill, storage in deep mines,
and the ocean.
Chemical (Leaching) Tests
The purpose of the chemical tests were
to provide a measure of the effectiveness
of the polyethylene jacket to prevent
migration of the toxic components from the
waste-binder (polybutadiene) agglomerate to
the environment. Sixteen sample blocks of
the waste were exposed to 8 different
aqueous solutions: distilled water, 10%
ammonium sulfide, 1.5 NHC1, 0.1 N citric
acid, 1.25 N NaOH, 0.1 N NH OH, a simulated
ocean solution, and 10% dioxane. These
solutions were selected to expose the blocks
to extremely harsh conditions, some of which
would not normally be encountered in
practice but which might represent a worse
case condition. The blocks were immersed
146
-------
into the solutions for 120 days (Figure 16).
Samples of the solutions were withdrawn on
a periodical basis (1, 2, 5, 10, 20, 30,
45, 60, 90 and 120 days) and analyzed for
selected components.
The concentration effects involved
because of sample withdrawal were considered
when calculating the concentration of the
cations over the sampling period. Details
of procedures, analytical techniques, and
results are available.* Summary results of
the sample analysis for cations after 120
days immersion indicate the effectiveness
of encapsulation to prevent release of the
components to the environment (Table 2).
Concentrations of the unencapsulated wastes
are provided in the right column. Of
particular interest are the results for the
citric acid and HC1 solutions, which repre-
sent good solvents for heavy metals.
High retention of the arsenic after 80
days immersion, contained in the encapsu-
lated monosodium methane-arsenate also
indicates the capability of the encapsu-
lation process to effectively control the
release of a wide range of potentially
toxic components to the environment (Table
3).
Figure 16. Encapsulated Wastes Specimens
Under Aqueous Solutions
TABLE 2. CONCENTRATIONS OF CATIONS (PPM) IN CHEMICAL TEST SOLUTIONS AFTER 120 DAY
IMMERSION OF THE ENCAPSULATED WASTE SPECIMENS*
Solutionst Distilled
Cations H2°
Cu
Cr
Zn
Ni
Cd
Na
Ca
Hg
.006
.012
.015
.085
.017
.218
.020
.001
0.33
325
.033
5.00
21.5
5,334
18,237
.002
Ocean
Water
.003
.030
.007
.004
.042
-
-
.002
91.4
0.34
1.50
0.40
984
-
-
1.05
NH4OH
.036
.003
.001
.088
.010
-
.016
.001
414
711
17.4
1.00
94.0
-
23.0
0.26
NaOH
.087
.008
.021
.068
.016
-
.006
.0003
339
5,884
15,519
0.2
1,500
-
44.3
.005
*Under each leachate, left column, encapsulated wastes; right, unencapsulated.
tSolutions: distilled water, simulated ocean water, 0.1N NH.OH, 1.25 N NaOH, 10% ammonium
sulfide, 0.1N citric acid, 1.5N HC1, 10% dioxane.
Contracts 68-03-0089 and 68-03-2037. Solid
and Hazardous Waste Research Division, U.S.
Environmental Protection Agency, Cincinnati,
Ohio 45268. Final reports are in prepa-
ration.
147
-------
TABLE 2. CONCENTRATIONS OF CATIONS (PPM) IN CHEMICAL TEST SOLUTIONS AFTER 120 DAY
IMMERSION OF THE ENCAPSULATED WASTE SPECIMENS* (CONTINUED)
Solutionst
Cations
Citric Acid
HC1
Dioxane
Cu
Cr
Zn
Ni
Cd
Na
Ca
Hg
.051
.009
.114
.093
.096
_
_
—
2,9
233
.089
2,589
8.3
_
_
—
.010
.012
.008
.055
.052
.035
.345
.0005
1,803
2,524
18,270
4,719
6,401
6,085
21,537
.004
.011
.035
.011
.168
.019
.218
.013
.019
25,035
127,390
8,231
42,352
106,416
45,098
590,650
171.5
0.14
.004
.004
.002
.037
.610
.146
.0003
5.9
71.6
1.6
5.5
19.5
4,834
134.9
.002
*Under each leachate, left column, encapsulated wastes; right, unencapsulated.
tSolutions: distilled water, simulated ocean water, 0.1N NH^OH, 1.25 N NaOH, 10%
ammonium sulfide, 0.1N citric acid, 1.5N HC1, 10% dioxane.
TABLE 3. ARSENIC AND SODIUM CONCENTRATIONS (PPM) IN TEST SOLUTIONS
Solution Blank Day Day
1* 80
Arsenic*
Distilled <.01 <.01 <.01
water
1.5 N HC1 <.01 <.01 <.01
Uncapsulated
Wastet
2,420
1,017
Comments
No arsenic detected
No arsenic detected
Sodium*
Distilled
water
Sodium
.050
(±.002)
.002
(±.001)
.191
(±.005)
.164
(±.001)
.21
(±0)
.176
(±.002)
10,685
10,919
No Na detected
Values within
Instrument noise
No Na detected
Values within
Instrument noise
*Days samples immersed in solution.
tValues determined for 400 grams of unencapsulated waste in 1200 ml of leaching solution
(equal to the encapsulated material).
^Determined by the silver diethyldithiocarbamate method.
^Determined by atomic spectroscopy.
Mechanical Tests
Tests were performed to evaluate the ability
of the encapsulated waste-binder agglom-
erate to withstand mechanical stresses.
These tests included measurements of com-
pression strength, freeze-thaw resistance,
impact strengths, puncturability, and a
measure of the bulk density. Variations
from standard testing procedures were re-
quired in some instances to accommodate
the test specimens and because of scaling
factors. Performance of the specimens,
however, was high and is typified by the
compressive strength at yield of approx-
imately 1600 psi. Although grossly
distorted, the jacket accommodated the
distortion and retained the hazardous waste
(Figure 17). Blocks exposed to freeze-thaw
cycles ruptured at approximately 1300 psi.
The density of the agglomerates tested were
90 to 100 Ibs/ft.
148
-------
Figure 17. Distortion Mode of Encapsulated
Hazardous Waste Under Unidirectional
Mechanical Pressure
Process Design
Engineering study yielded a process
flow sheet, a potential plant design, and
provided estimated costs for fabricating
production scale encapsulated waste
products. This study characterized the
production products as follows: dimensions,
cubic, approximately two feet on edge;
weight, in the range 800 to 1000 pounds;
jacket, about 1/4 inch thick polyethylene
resin; encapsulate, hazardous waste
agglomerate cemented by 3 to 4 percent w/w
polybutadiene resin.
The cost was estimated at $91 per ton
dry waste at 20,000 tons per year through-
put. Studies relating cost to various
parameters indicated that the most cost
sensitive area was the cost of resins,
accounting for approximately 50 percent of
the total cost. The cost was based upon
the price of commercial resins, but "crude"
and/or scrape resins appear to be applic-
able, especially polybutadiene. Con-
sequently, potential exists for significant
reduction of cost.
Details of the suggested process,
including mass and energy balances are
available.
CONCLUSIONS
Results of the study and evaluations
described in this paper led to the follow-
ing conclusions:
o Polybutadiene resin is an effective
medium for producing hazardous waste-
binder agglomerates containing 94
to 97% by weight of waste.
o Waste-binder agglomerates can be
securely encapsulated with 1/4-inch
thick polyethylene jackets by fusing
powdered polyethylene onto agglom-
erate surfaces, yielding passivated
hazardous waste.
o Based upon process performance under
laboratory chemical and mechanical
stress tests, the encapsulation of
waste-binder agglomerates would be
expected to provide a high degree of
control over the release to the
environment of unwanted quantities of
the hazardous waste tested.
o Difficult to manage hazardous waste
containing constituents such as
sodium metaarsenate and arsenic
trisulfide were assessed to be
amenable to control by the polymeric
encapsulation process described in
this paper. Based upon the process
evaluations and associated assess-
ments, the process appears to be
compatible with a wide range of
hazardous waste which may not be
adequately manageable by other
techniques.
o The process as designed is expensive;
estimated at $91 per ton of dry waste
for a plant processing 20,000 tons
per year. Commercial resins were
determined to account for more than
50% of the product production costs.
However, studies suggest that these
costs can be significantly reduced
by use of crude or scrap resins.
RECOMMENDATIONS
Additional study is recommended to
evaluate large production scale blocks
(800 Ibs) of encapsulated hazardous waste-
binder agglomerates under actual field
disposal conditions. Engineering design
modifications, as well as evaluations of
149
-------
less costly crude resins, are required to
provide a less costly process.
The process as described appears to
be costly in comparison to other available
techniques for managing hazardous waste.
Assessments are required, however, to
better .define the costs of the process
versus its potential ability to manage
hazardous waste that other processes may
not control within environmentally accepta-
ble levels. For such cases, costs of the
process will become of secondary importance.
REFERENCES
1. Lehman, J. P., "Federal Program for
Hazardous Waste Management." Waste
Age (Sept. 1974).
2. "Disposal of Hazardous Wastes", Report
to Congress, SW-115. Environmental
Protection Agency (1974).
3. Johnson, H., "Hazardous Waste Disposal
Studies'7. Waste Age (March, April
1973).
4. Landreth, R. E. and Rogers C. J.,
"Promising Technologies for Treatment
of Hazardous Wastes". EPA 67012-74-
088, National Environmental Research
Center, Office of Research and
Development, U.S. Environmental
Protection Agency, Cincinnati, Ohio
(Nov. 1974).
150
-------
AN EVALUATION OF STORING NONRADIOACTIVE HAZARDOUS WASTE IN MINED OPENINGS
C. C. Wiles
U.S. Environmental Protection Agency
26 W. St. Clair Street
Cincinati, Ohio 45268
ABSTRACT
An assessment was made of the technical feasibility of storing nonradioactive
hazardous wastes in underground mined openings. Since environmental protection was the
most important concern, basic criteria were established which had to be met before the
concept could be considered technically feasible. These basic criteria were established
so that a maximum level of environmental protection could be assured and the potential
for hazardous wastes stored underground to be carried from the mine in either air or
water would be minimized. These criteria include: geologic stability in and around
underground facility; hydrologic and surface isolation; chemical compatibility of the
stored wastes with each other and the host medium; personnel safety; underground mining
regulations and restrictions; and long term flexibility to meet changing conditions. The
results show that a majority of the wastes considered can be stored underground in an
environmentally acceptable manner if they are properly treated and containerized. Various
mine environments in the United States are applicable for such storage; room and pillar
mines in salt, potash, and gypsum appear to be the most favorable. Although the under-
ground storage and management of hazardous industrial wastes is both technically feasible
and environmentally sound, further and more detailed research, including an economic
evaluation, is recommended.
INTRODUCTION
This paper deals with the concept of
using underground mined openings in salt
and other media as a respository for non-
radioactive hazardous wastes. An assess-
ment was made of the technical feasibility
from an environmental point-of-view.
Throughout the study, the prime consider-
ations were an assessment of the potential
effects on the environment and that storage
of the hazardous wastes would be ac-
complished in such a manner that associated
environments were not harmed.
The concept of using underground
cavities as disposal sites for hazardous
wastes is certainly not unique. The United
States Atomic Energy Commission conducted
intensive investigations of storing radio-
active wastes. Although found feasible,
some technical uncertainties related to the
actual waste storage concept and socio-type
problems prevented implementation of the
concept (1). This is not true in the
Federal Republic of Germany where the Asse
Salt Mine began processing and disposing
of low-level radioactive waste in April of
1967. Intermediate level radioactive waste
was accepted in August of 1972, and test
disposal of solidified high-level radio-
active waste is scheduled for 1976-1977 (2).
There are no known underground mines
processing and storing hazardous (non-
radioactive) waste in the United States.
However the similarity of problems of
storing hazardous wastes to those of storing
radioactive wastes has been recognized.
Germany began consideration of the concept
in their June 1972 Federal Waste Removal
Law. Review of selected provisions of that
law indicate that parties engaged in mining
operations or the operator of a mineral
151
-------
extraction enterprise may be "obligated" by
an "appropriate authority" to "tolerate the
elimination" of wastes in cleared-out
sections of his facility and to make the
facilities available for such purposes. As
a result, some enterprising companies, after
meeting certain legal requirements and
receiving Government approval, began to
offer and promote the service of underground
storage and disposal of toxic chemical
wastes (3).
The problems of increasing quantities
of industrial and other wastes containing
toxic components and their associated
management (or mis-management) has been
documented (4). Technologies have been
identified which offer acceptable treatment
alternatives for selected hazardous wastes
(5). In many cases the wastes can be re-
duced to nontoxic materials. However, we
must recognize that technologies are not
available to reduce all toxic wastes to
nontoxic forms. Therefore, alternative
techniques must be investigated and
developed to manage these toxic residuals.
The study discussed in this paper was con-
ducted as a portion of a broader Federal
program directed at assessing technologies
available and potentially available for
treating and managing hazardous wastes (6).
The use of underground space in salt
deposits for the long term retention of
hazardous waste is considered a very
promising candidate technique for managing
toxic residuals. The study discussed in
this paper further explored the concept.
Although salt appeared to be the best
candidate, other media were considered.
Since the overriding study consider-
ations were environmental concerns, basic
criteria were established which had to be
met before the concept could be considered
technically feasible. These basic criteria
were established so that a maximum level of
environmental protection could be assured
and the potential for hazardous wastes
stored underground to be carried from the
mine in either air or water would be
minimized. These criteria include: geologic
stability in and around an underground
facility; hydrologic and surface isolation;
chemical compatibility of the stored wastes
with each other and the host medium;
personnel safety; underground mining regu-
lations and restrictions; and long term
flexibility to meet changing conditions.
As an added incentive to assure the
application of strict criteria to the
study, and for socio-related reasons, the
study team adhered to a basic philosophy
developed early in the study. This phi-
losophy involves the concept of controlled
storage rather than disposal of the waste.
The latter connotates placement of waste
in the mine with little or no subsequent
control of its disposition; similar to the
"open dump1'. The former is proposed to
permit emplacement of the waste for both
short and long-term retention under engi-
neered and controlled conditions. The
waste disposition would be continually
monitored and if determined necessary
because of impending problems, transferred
from one site to another. Also, in the
event of future changes in technology, or
for appropriate economic incentives,
selected wastes would be available for
recovery and redistribution for useful
purposes.
PROBLEM DEFINITION
Investigations Required
Assessment of the environmental
acceptability for storing hazardous waste
underground involved the following investi-
gations:
o The development of geological
criteria which can be used to
select those sites providing
maximum environmental protection
for the emplacement of hazardous
industrial wastes.
o The characterization of hazardous
industrial wastes to determine if
they could be placed in underground
mines in an environmentally accepta-
ble manner.
o The determination of the potential
for wastes to migrate from the mine
environment.
o An evaluation of the capability of
existing equipment to detect, monitor,
and control potential waste con-
tamination and migration.
o An evaluation of mine design, con-
struction, and operating requirements
necessary to ensure safe operation
and complete environmental protection.
152
-------
Although not within the scope of this
study, additional work is being initiated
to determine economic feasibility.
Approach
Based upon the primary objective of
assessing the environmental acceptability
of the concept, the study was divided into
the following major tasks (Figure 1):
o Problem Definition
o Geological Characterization
o Waste Characterization
o Geochemical Assessment
o Detection, Monitoring, and
Control Technology
o Regulations Assessment
o Mine Design
o Conclusions
STUD* ORGANIZATION
CONTROL
MONITORING
REVIEW
Figure 1. Study Organization
A concurrent review of the available
literature pertaining to underground mines,
subsurface disposal problems, industrial
waste streams, and current waste disposal
or storage techniques identified three
major problem areas concerning waste
isolation:
o The physical and geological environ-
ment of an underground storage
facility.
o The chemical and hazardous nature of
the wastes.
o The geochemical compatibility of the
wastes with mine environments.
These were considered to be of primary
concern in determining the environmental
acceptability of the concept. However, to
provide a more realistic assessment of the
concept, it was also necessary to evaluate
the following:
o Detection, monitoring, and control
technology.
o Regulatory aspects of waste storage
in mines.
o Design of an underground waste
facility.
Although important, the economic
aspects of this storage concept were not
directly addressed. However, in approach-
ing each area of the study, broad economic
considerations were often unavoidable when
choosing one alternative over another.
MAJOR STUDIES
Geology and Mine Selection Criteria
Lithologies
Basic lithologies for evaluation were
selected on the basis of known character-
istics and physical occurrence. Salt,
having received the greatest previous
attention as a waste disposal medium, was
of primary interest. Other evaporites
(gypsum and potash) were investigated due
to their similarity, occurrence, and
development. Other lithologies were
selected on the basis of their proven
storage potential of hydrocarbon products,
geographic occurrence, minability, and
general characteristics.
Limestones were considered because
they occur in many areas of the United
States, are often mined, and appeared to
satisfy many of the geologic and mine
criteria. In addition, by determining the
suitability of limestone, other related
lithologies would also be indirectly con-
sidered. The most important of these is
dolomites which are generally stronger,
commonly mined, and widely distributed.
153
-------
Shales were chosen because of their
widespread occurrence and potential for
beneficial reactions (ion exchange capacity)
with the wastes. Although not commonly
mined, shales are generally impervious and
have been successfully used for the storage
of liquid petroleum products.
Granite is less uniform (homogeneous)
than the other selected lithologies and is
not typically mined by room and pillar
methods. It is also often associated with
mountainous terrain. On the other hand, it
is a very competent lithology and is
essentially impervious except where locally
fractured. It does not weather easily,
which implies little reactivity to weather-
ing agents, occurs in large geographic
areas, and has been mined by room and pillar
methods for hydrocarbon storage.
Selection of candidate lithologies
recognized that general characterizations
are not wholly practical or realistic.
However, to meet the study objectives,
certain generalizations were required. The
lithologies considered in this study are
believed to be the most promising. This
list, however, is not restrictive and other
lithologic environments could be added as
required.
Preliminary Decision Model - Waste Storage
Mines
To facilitate the evaluation of
lithologic environments and mined openings,
a preliminary decision model was developed
(Figure 2). Using this model, it is
possible to screen any mined environment
for preliminary suitability. By subjecting
all potential underground storage sites to
this screening technique as information
becomes available, it will be possible to
arrive at a listing of the most promising
sites. These sites can then be further
evaluated and subjectively compared.
TENTATIVE REJECT
WET-IMPERVIOUS
UNCERTAIN
ACCEPTABLE
ALL UNDERGROUND MINES
ALL ROOM AND
PILLAR MINES
H DRY & IMPERVIOUS
H WELL ISOLATED
REJECT
-
-
H
MINES OF OTHER DESIGNS
WET-PERMEABLE
NOT ISOLATED
DETERIORATED
HETEROGENEOUS
SEISMICITY
MINOR & INACTIVE
FAULTING
DEEPER THAN 600 METERS
VARIABLE
LONG-TERM POTENTIAL
THIN S/OR LIMITED
OCCURRENCE
MODERATE RELIEF
LONG-TERM POTENTIAL
H STRUCTURALLY STABLE
-
HREACTIVITYSHOMOGENEITYh
-, 1
H NO SEISMICITY
]H NONFAULTED
-i| LESS THAN 900 METERS
H LOW INCLINATION
1
EROSION, ALTERATION
DISSOLUTION
H THICK S WIDESPREAD
-1 |
HLOW SURFACE RELIEF
NOT SUBJECT TO:
]- GLACIATION -
OCEAN INUNDATION
OTHER CONSIDERATIONS
S ECONOMICS
H
H
H
H
UNSTABLE
HIGHLY REACTIVE
HIGH SEISMIC RISK |
ACTIVE FAULTING
DEEPER THAN 900 METERS I
GREATER THAN 10U 1
-f
•f
H
SHORT-TERM POTENTIAL |
HIGH RELIEF I
SHORT-TERM POTENTIAL
Figure 2- Preliminary Decision Model -
Hazardous Waste Storage Mines
Geochemical and Waste Characterization
Analysis
Acceptability of Waste for Storage Under-
ground
Characterization of the wastes con-
cerned determining the environmental
acceptability of the wastes for underground
storage. This determination was approached
from three main viewpoints:
o An investigation of the physical,
chemical, and hazardous properties
of the wastes to assess their
acceptability for underground
storage before and after treatment.
o The control of possible environmental
contamination through proper treatment
and containerization.
o An investigation of possible environ-
mental degradation which may occur
after storage from the chemical
interaction of the wastes with each
other and with the geological for-
mations or from waste migration.
154
-------
Until very recently, studies have been
primarily concerned with identifying and
analyzing the most hazardous constituents in
waste streams rather than a total waste
stream analysis. This type of analysis has
been called the "pure-form" approach and
assumes the properties of a waste stream
to be identical to those of its most hazard-
ous constituent. Although the most real-
istic characterization of wastes will
require a complete waste-stream analysis,
it was necessary to use the "pure-form"
approach due to the lack of available infor-
mation on total waste streams. However,
the methodology for analysis that was
developed can be applied equally well to
either "pure-form" wastes or waste-streams.
As additional waste-stream data are obtained,
new candidates for storage in underground
mines can be realistically screened using
the developed methods.
During the EPA evaluation of the
hazardous waste problem 115 wastes were
identified as special problems, and were
recommended for disposal in National
Disposal Sites (NDS)(7). These were con-
sidered as the candidate wastes for storage
in a mined facility.
The waste characterization method
developed consists of the following steps:
o Compile and present the physical and
hazardous properties for the wastes
of concern.
o Define and establish the criteria
for "ideal" waste form for under-
ground storage.
o Develop a Hazard Index rating of the
wastes to indicate their accepta-
bility as candidates for under-
ground storage without pretreatment
(Figure 3).
o Screen and divide the wastes
according to their Hazard Index
into those which require:
a. no pretreatment
b. optional pretreatment
c. mandatory pretreatment
o Compile and present the best waste
treatment procedures available for
rendering the wastes to their most
ideal form for underground storage.
o Further screen and divide the wastes
into those which:
a. are acceptable for underground
storage without pretreatment
b. must be treated and whose treatment
products are toxic, but acceptable
for underground storage
c. must be treated and whose treatment
products are essentially nontoxic,
but acceptable for underground
storage
d. must be treated and whose treatment
requires further study
e. are unacceptable for underground
storage in any form.
o Define and explain any potential
reactions that could occur between
the stored wastes after they are in
place in a mine.
o Define and explain any potential
reactions that could occur between
the stored wastes and the receiving
geological formations.
o Assess the potential for migraton
of the wastes.
FL ARABLE
0 TO 7
HAZARD
HAZARD
HAZARD
0-HO HAZARD
EXPLOSIVE
7-SEVERE
HAZARD
HAZARD
1 AZARD
0-1(0 HAZARD
CATEGORY 3
EVOLVE GAS IN
AIR OR 'IATER
0 TO 3
3-SEVERE
HAZARD
HAZARD
1-SLIG T
HAZARD
0-HO HAZARD
CATEGORY 4
EVOLVE GAS
0 TO 3
3-SEVERE
HAZARD
1-SL1GIT
HAZARD
0-1(0 HAZARD
CATEGC
SOLUBLE
RY Li
Irl H,0
Z-SOLUBLE
SOLUBLE
0-IIISOLUBLE
CATEGORY 6
TQX C
3-SEVERE
HAZARD
1 -SLIGHT
0-110 HAZARD
Figure 3. Hazard Index of Candidate Wastes
155
-------
The environmental acceptability of a
hazardous waste underground depends upon
the level of hazard it presents prior to
storage. A waste must be evaluated with
respect to potential effects on the bio-
sphere resulting from its handling,
treatment, storage, or possible migration.
If it was found that a waste was too
hazardous to the environment in its pure
form, then its hazards could, in most cases,
be reduced through treatment. The treatment
procedures, as presented in the study
report, are theoretical in nature.
It was assumed that each waste would
be containerized for storage. This
assumption was based upon many factors.
From an environmental standpoint, the con-
tainerization of the wastes would provide
maximum safety during handling and storage
while minimizing the potential for con-
tamination of the biosphere through mi-
gration. In addition, if it became
feasible to recycle a waste or an environ-
mental calamity was eminent, containeri-
zation would allow a waste to be retrieved
from storage without danger. For these
reasons, it was concluded that hazardous
wastes should be stored in mines according
to the Bureau of Mines safety requirement
30 CFR, Chapter 1, part 57, 16-4 which
reads as follows: "Mandatory - Hazardous
materials shall be stored in containers of
a type approved for such use by recognized
agencies; such containers will be labeled
appropriately."
Waste Interaction
Once a waste has been placed under-
ground, the possibility of environmentally
hazardous compounds being formed by
chemical reactions among the stored wastes
must be assessed. It was assumed that, in
the event of a mine flood, the containers
would rupture allowing the wastes to go
into solution. Although this situation
could be prevented by proper treatment and
contalnerization, the "worst case" phi-
losophy was employed. Under these con-
ditions, the number of potential chemical
reactions is staggering. Due to the
enormous number of possible reactions,
consideration of only the immediate or first
level reactions was within the scope of the
study.
In an attempt to evaluate the types of
reactions which might occur, a waste inter-
action matrix utilizing the "Acceptable
Form" was developed.* The "Acceptable Form"
of a waste can be defined as the waste which
has been treated to its lowest level of
toxicity or hazard so that it approaches
the following guidelines:
o Nonflamible
o Nonexplosive
o Will not evolve hazardous gases when
exposed to air, water, or heat
o Containerized
o Unable to be dispersed in air or
water in concentrations exceeding
the established TLV for the material
The reactions are then described as hazard-
ous and nonhazardous. A hazardous reaction
is one in which either of the following
might occur:
o Potential for migration of a waste
is increased by the formation of a
more soluble toxic compound.
o New substances are formed which
present greater hazards to the
environment than the original
substances.
Geochemical Interaction and Compatibility
Since environmentally unfavorable
reactions may occur for the chemical inter-
action of the stored wastes with the
receiving geological formations, an
evaluation of this was a necessary step in
determining the environmental acceptability
of the concept. An unfavorable reaction
would be one in which any of the following
might occur:
o The potential for migration of a
waste is heightened by an increase
in its solubility through complexing
or ionization.
o The structural integrity of the
lithology is unfavorably altered.
o Any new substances are formed which
present greater hazards to the
environment than the original
substances.
*EPA Contract 68-03-0470, Solid & Hazardous
Waste Research Division, Environmental
Protection Agency, Cincinnati, Ohio 45268.
Figures and details of the waste interaction
matrix are too complicated for reproduction
in this paper.
156
-------
In a favorable reaction, the reverse
of the above would be true. If an un-
favorable reaction occurs, a waste is said
to be incompatible in a lithology. If a
favorable reaction or no reaction occurs,
a waste is said to be compatible in a
lithology.
The lithologies which were selected
as candidate formations for storage are:
o Rock salt (Halite)
o Gypsum
o Potash (Sylvite)
o Shale (1) (Relatively high
montmorillonite content)
o Shale (2) (Relatively low
montmorillonite content)
o Limestone
o Granite
For the purposes of this analysis, it
was assumed these lithologies were homo-
geneous in composition and that any im-
purities normally found within them would
not occur in amounts sufficient to alter
the basic reactions between the wastes and
the lithology.
In this investigation, the "worst case"
analysis was again employed. The storable
wastes were assumed to be in contact with
the selected lithologies under both wet
and dry conditions. These conditions would
not be possible unless the waste containers
were ruptured by some calamity such as
flooding. The reactions resulting from the
interaction of the wastes and receiving
formations could be controlled through
proper treatment and containerization.
However, this analysis was necessary to
ensure the appraisal of all conditions
which might adversely affect the environ-
ment.
Projected Waste Volumes
The last step in evaluating the wastes
as candidates for underground storage is
to investigate their probable volumes.
This is important in order to obtain some
idea of the magnitude of the problem of
waste disposal and to assess mined storage
as a potential answer. Previous studies
have estimated waste volumes and established
a relationship between population concen-
tration and volume of waste generated.
Waste Migration
The primary result of the investi-
gation of the potential environmental
effects of waste migration is that mi-
gration can be avoided if the proper
techniques of waste treatment and con-
tainerization are employed. Two principle
methods by which a waste may migrate from
the mine are to be carried by ground water
and by reacting with host rock. Both of
these are dependent upon the solubility of
a waste. Therefore, decreasing the solu-
bility of a waste during treatment should
be of major concern. Since the goal of
underground storage is the complete
isolation of the hazardous wastes from
the biosphere, the potential migration of
the wastes must be controlled. Perhaps
the best method of avoiding migration is
through the use of containers. If a
stored waste is never allowed to contact
the mine environment, there would be no
chance of it escaping. One disvantage of
containers is that their use could become
economically prohibitive.
A reasoning sequence was used to
analyze each waste for its acceptability
for storage underground (Figure 4). This
aid was developed to help insure that study
criteria were properly considered. It
provides a review of the assessments made
to determine the acceptability of wastes
that are candidates for underground storage.
I
HI-0-5
NO TREATMENT
1
i
1
CHEMICAL 1
rflMPATTnil [TV 1
1
1
(UNRESTRICTED 1
1
1 HAZARD ANALYSIS
n
1
HI-6-9
OPTIONAL TREATMENT
HI-10-.Jb
IIArlDATORY TREATMENT
1
TREATMENT PROCEDURES
(HAZARD REDUCTION)
1
1
ACCEPTABLE J
1
GEOCHEMICAL
1 COMPAT BILITY
1
| RESTRICTED
1
1 veil UME STUDY
1
1
| HOT ACCEPTABLE
1
1
i
I DEGREE OF PROBLEM SOLUTION
Figure 4. Simplified Waste Characterization
Analysis Flow Diagram
157
-------
Detection, Monitoring and Control
The emplacement, storage, and manage-
ment of noxious chemical wastes in under-
ground mined openings will require con-
tinuous surveillance of the mine opening,
contiguous subsurface areas, and surface
environments. The implementation of
detection monitoring and control systems
will help insure isolation and safety by
providing early warning of contamination
in air and water and will also allow early
detection of structural fatigue. By
these means the potential for waste inter-
action with the biosphere can be strictly
controlled.
The basic requirements of a detection,
monitoring, and control system will include
the following:
o Continuously monitor, sample, and
clean the circulating mine air.
o Provide immediate response (alarms,
etc.) to critical changes.
o Indicate long-term finite changes.
o Allow source area identification.
o Provide qualitative and quantitative
analysis of contaminants in air and
water.
o Provide high reliability.
o Be adaptable to change and im-
provement as the technology advances.
o Provide decontamination capability.
o Allow recovery and storage of
released wastes.
The importance of monitoring the short
and long-term structural integrity of a mine
used for housing hazardous wastes involves
several aspects of this storage concept.
Of immediate interest is the safety of
personnel working in the facility. Such
things as roof falls and slabbing are
hazards which can normally be prevented by
good maintenance practices. Hazards of a
larger consequence would result if such
failures were to rupture containers. If
this occurred, not only would mine personnel
be put in jeopardy, but the entire waste
facility might be lost temporarily, or even
permanently. To guard against such an
occurrence, mines must be selected with
high regard to stability; and to provide
additional insurance, various monitoring
instruments and techniques should be
implemented. Instruments which are
presently available can provide finite
measurements of short and long-term changes
and thus allow preventative measures to be
taken before failure occurs.
The hydrologic environment in the area
of an underground hazardous waste storage
facility will require monitoring to assure
isolation of the wastes and protection to
the environment. Streams, springs, and
wells in the vicinity can be physically
sampled using standard methods and the
samples then analyzed in a laboratory.
Regulation Assessment
Many existing laws and regulations are
related to hazardous and potentially
hazardous substances that could affect the
quality of our environment. The objectives
of these laws are, in general, to improve
the quality of the environment and to
protect it from further pollution by es-
tablishing national standards. Some of these
laws are related to disposal of waste
products, however, no laws or regulations
were found to directly govern the disposal
or storage of nonradioactive hazardous
waste products in underground salt deposits
and/or mined openings.
ADDITIONAL MINE CONSIDERATIONS
The concept of long-term storage of
hazardous industrial wastes in underground
mines appears feasible and might be preferred
to surface storage for several important
reasons. Among these are:
o It is well protected.
o It provides permanent, very long-term
containment.
o Valuable surface area is not used.
o It provides good security and control
of access.
o It requires a minimum of maintenance.
o Storage space can be continuously
expanded.
158
-------
o There is less chance of damage to
the environment in case of a spill.
o The facility could possibly be
designed to survive a nuclear blast.
o It is protected from the ravages of
the weather.
o A nearly constant temperature exists
underground.
o Humidity would not vary excessively.
o The waste would be out of sight.
o It is less subject to sabotage.
There are many different types of
mines existing today that have been exca-
vated using numerous mining methods. Of
the many mining methods in use, the room
and pillar method appears to be best suited
to the storage of wastes underground. The
room and pillar method consists of mining
a number of parallel rooms (drifts) in the
formation and connecting them by means of
another series of parallel rooms (crosscuts)
mined at right angles to them. The room
and pillar mining method is generally
reserved for deposits that can be mined
nearly horizontal.
Some advantages of the room and pillar
mine as opposed to other types that could
be used for hazardous waste disposal
include:
o The mine layout is usually near
horizontal or has a low dip with
the underground workings generally
all on one level. In most cases
the grade is shallow enough to
permit the use of rubber tired
equipment.
o The rooms are generally large.
o Large equipment can be used if
required to handle heavy or bulky
loads.
o The mine is relatively simple to
excavate.
o The mining plan provides for con-
siderable flexibility in overall
layout.
o Mine ventilation is simplified.
o Mine haulage is simplified.
A preliminary assessment was made of
the relationship between the location of
potentially suitable underground mines to
the volume of hazardous industrial waste
generated. It is clear that every region
where significant quantities of waste are
generated contains at least a few operat-
ing mines in the selected lithologies.
Several of these mines can be expected to
meet the criteria for hazardous waste
storage.
Waste Handling Procedure
The overall operation of the storage
facility must be well planned and coordinated,
The more important operations of a hypo-
thetical hazardous waste storage facility
is described in order to point out key
operations.
The waste material, as received at the
storage site, may be in a storage container
and a form suitable for final storage. On
the other hand, it may be more economical to
ship the waste in large, bulk tank cars to
the storage site where it would then be
transferred to smaller containers for
permanent underground storage. Economics
or other conditions may also dictate that
some of the waste products be reprocessed
at the storage site prior to being
permanently containerized and stored. These
are variables that would have to be con-
sidered in the final design of a hazardous
waste storage facility.
Once the waste has been received at
the site, careful inventory controls must
be maintained at all times. This is
necessary in order to keep close check on
the waste reprocessing and recontainerizing,
if any, and to verify that each given waste
product is stored in the proper storage
cell underground. A flow diagram was
developed to illustrate the possible waste
handling steps (Figure 5). The health
and safety staff would monitor the waste
handling processes from the time the waste
arrives at the site until it is safely
stored underground.
159
-------
Figure 5. Waste Handling Flow Chart
CONCLUSIONS
The following conclusions are based
upon the assessments made during this study:
o Storage in underground mines is an
environmentally acceptable method
managing hazardous industrial wastes
provided the recommended procedures
of site selection, treatment, con-
tainerization, and waste handling
are followed.
o Environmentally suitable underground
space for the storage of hazardous
industrial wastes now exists within
the United States.
o Room and pillar mines in salt,
potash, and/or gypsum offer the
most suitable containment with
respect to the study criteria.
o The first-level chemical interaction
of storable hazardous industrial
wastes with each other or with the
receiving geological formations will
not create any uncontrollable
situations.
o The potential for waste migration
out of a properly selected mine
is slight and can be controlled
through proper treatment, contain-
erization, and site selection.
o Systems adequate to detect, monitor,
and control waste migration can be
developed from current technology.
o A need for legislation concerning
the storage of hazardous industrial
waste in underground mines is
indicated.
o The design and operation of an
underground storage facility for
hazardous industrial wastes is
technically feasible.
o Locating regional waste storage
facilities at existing mines is
technically feasible.
DISCUSSION AND RECOMMENDATIONS
Procedures were developed to assess
selected lithologies as environmentally
acceptable storage sites for nonradio-
active hazardous waste. These procedures
are applicable to the evaluation of
specific sites. Once identified as a
candidate storage site, detailed physical
and geological evaluations of the mine
should be conducted using the criteria
and techniques outlined. In a like manner,
because of the unique physical nature of
each mine, the potential for waste migration
from each specific site should be assessed
even though migration is considered unlikely.
The concept appears technically
feasible. Economic feasibility, however,
has not been determined and should be
before performing additional technological
evaluations.
Throughout the study, decisions to
either accept or reject waste for under-
ground storage, or for accepting or
rejecting lithologies, or for similar
matters, were based upon strict and
demanding criteria aimed at providing
maximum protection to the environment. If
a waste were judged to be unacceptable
for storage based upon its hazard rating,
it was rejected. In reaching such decisions,
no attempt was made to judge the relative
degree of hazard of storing the waste
underground as opposed to some other dispo-
sition. For some waste, storage under-
ground may be the test alternative manage-
ment technique available. In addition,
further evaluations may determine that the
technical criteria established for accepting
160
-------
or rejecting waste for storage are too
restrictive. This would only increase the
concept's potential as a safe management
technique for nonradioactive hazardous
waste.
REFERENCES
1. Brandt, C. T. "Use of Salt Resposi-
tories for Long-Term Retention of
Hazardous Waste Materials". AOA Fourth
Annual Symposium on Environmental
Pollution (April 1973).
2. Kuhn, K. "Asse Salt Mine Federal
Republic of Germany - Operating
Facility for Underground Disposal of
Radioactive Wastes", Vol. 2, Under-
ground Waste Management and Arti-
ficial Recharge (Sept. 1973).
3. Herfe-Neurode Underground Waste Disposal
Facility, A Contribution to Environ-
mental Protection (from Company
Document).
4. "Disposal of Hazardous Waste", Report
to Congress, SW-115. Environmental
Protection Agency (1974).
4. Landreth, R. E. and Rogers, C. J.
"Promising Technologies for Treatment
of Hazardous Wastes". EPA 67012-74-
088, U.S. Environmental Protection
Agency, Cincinnati, Ohio (Nov. 1974).
6. Lehman, J. P. "Federal Program for
Hazardous Waste Management". Waste
Age (Sept. 1974).
7. Johnson, H. "Hazardous Waste Disposal
Studies". Waste Age (March-April
1973).
161
-------
EVALUATION OF SELECTED SORBENTS FOR THE REMOVAL OF
CONTAMINANTS IN LEACHATE FROM INDUSTRIAL SLUDGES
J.W. Liskowitz*, P.C. Chan*, R.B. Trattner*, R.
Dresnack*. A.J. Perna*, M.J. Sheih*. R. Traver*
and F. Ellerbuscht
ABSTRACT
This paper presents the laboratory results of the evaluation of ten natural and syn-
thetic materials (Bottom Ash, Fly Ash, Vermiculite, Illite, Ottowa Sand, Activated Carbon,
Kaolinite, Natural Zeolites, Activated Alumina, Cullite) for the removal of contaminants
in the leachate and liquid portion of three different industrial sludges (Calcium fluoride
sludge, Petroleum sludge, Metal finishing sludge). This investigation involves beaker
studies to evaluate the static absorption capacity of sorbent materials using maximum
background concentrations of contaminants in the leachate; followed by lysimeter studies
to obtain information regarding the dynamic absorption capacity and permeability charac-
teristics of these materials. The analysis of the leachate involves the determination of
pH, conductivity, residue, chemical oxygen demand (COD) total organic carbon (TOG), anio-
nic species, and cationic species before and after contact with sorbent materials. The
results of the beaker studies show that there is no single sorbent of those examined that
can significantly reduce the concentration of all the constituents in a leachate to accep-
table levels. Initial results using the lysimeters, confirm these findings. The results
however, indicate that combinations of different sorbents can be used to reduce all the
contaminants in the leachates obtained from a specific sludge to acceptable levels. The
selection of the combination of sorbents to treat a given leachate depend upon the sludge
and contaminants in the leachate.
INTRODUCTION
As a result of the establishment under
the Federal Water Pollution Control Act of
1972 of a no pollutant discharge policy to
receiving waters by 1985, industry will be
faced with finding feasible techniques for
the safe disposal of hazardous and toxic
sludges generated during the treatment of
their industrial waste streams. In the
main, the most often used sludge disposal
technique for industrial sludges has been
sanitary landfills. Some progress has and
is being made in the development of closed-
*Environmental Instrumentation Systems
Laboratory, New Jersey Institute of Tech-
nology, Newark, New Jersey.
tlndustrial Environmental Research Labora-
tory, Environmental Protection Agency,
Edison, New Jersey.
loop type waste treatment, however, this
technology is not expected to significantly
reduce the sludge volume in the near fu-
ture. The disposal of industrial sludge in
landfills can, however, lead to contamina-
tion of ground and surface waters by the
pollutants in the liquid portion of these
wastes. Also, pollutants may be transpor-
ted to the ground or surface water as a
result of ground water infiltration or rain-
water percolating or leaching through the
landfill (1).
At present, there is a lack of means
to accurately predict the leaching poten-
tial, and direction and rate of flow of the
leachate through the soil surrounding the
landfill site(2). These problems could be
overcome by isolating the landfill site
from its immediate soil surroundings. By
lining the base and sides of the landfill
162
-------
with compacted low impermeable loess soil,
horizontal groundwater movement of the
leachate is prevented (3). Polyvinyl chlo-
ride and butyl rubber liners have also been
used for this purpose (A) (2). This how-
ever, creates a "bath tub without a drain"
unless the rainwater that percolates down
through the landfill is provided a means of
escape. This could be accomplished using
gravity outlets such as drainage tiles or
perforated corrugated metal pipe installed
in the lowest portion or along the base of
the landfill (3)(2)(5) to remove and col-
lect the leachate. Further treatment of
the collected leachate would be required to
reduce the pollutants to acceptable dis-
charge levels, assuming that treatment
technology is available. In any event,
additional construction and operating costs
would be required.
We now propose a different approach to
remove hazardous materials in the leachate
within the landfill site and eliminate the
need for additional treatment of the leach-
ate. The approach is to line the landfill
site with an impermeable membrane and to
remove the leachate from the landfill and
permitting it to percolate through a bed of
inexpensive material whose sorbent and ex-
change characteristics are satisfactory for
reducing the concentration of pollutants to
acceptable discharge levels thereby pre-
venting contamination of ground and surface
waters.
A laboratory study was conducted in
order to evaluate the effectiveness for
contaminant removal of ten natural and syn-
thetic sorbent materials on the leachate
and liquid portion generated from three
different industrial sludges. The sludges
chosen for this study were a calcium fluo-
ride sludge (of the type generated by the
electronic and air-craft industries), a
metal finishing sludge and a petroleum
sludge. These sludges were selected be-
cause their annual production is of a sig-
nificant magnitude to present disposal
problems and the leachate from these
sludges would contain a cross-section of
hazardous and toxic organic constituents,
heavy metal hydroxides, toxic anions such
as cyanide and substantial amounts of fair-
ly soluble toxic salts such as calcium
fluoride. The sorbent materials used are
fly ash, bottom ash, Ottowa sand, activated
carbon, illite, kaolinite, vermiculite,
natural zeolites, cullite and activated
alumina (mesh size <325; 48-100 and <100).
Container studies were conducted to eval-
uate the batch-wise "static" sorption and
exchange capacity of the sorbent materials
using maximum background concentrations of
contaminants in the leachate. These batch
studies are then followed by lysimeter
studies in order to obtain information re-
garding the dynamic capacity and permeabi-
lity characteristics of these materials.
Leachate analysis involved the determina-
tion of pH, conductivity, residue, chemical
oxygen demand (COD), total organic carbon
(TOC), anionic species and cationic species
before and after contact with sorbent mate-
rials .
EXPERIMENTAL
Preparation of Sorbent Materials
All sorbent materials were used as
received. Sorbent materials which were not
obtained as a powder (i.e., illite, bottom
ash and vermiculite) were ground and passed
through an 80-mesh A.S.T.M. standard sieve.
All sorbents were dried to constant weight
at 103°C (in accordance with "Standard
Methods") and stored in a dessicator until
used.
Preparation of Sorbent Leachate
Background mixtures of deionized water
and dried sorbent material were prepared in
the ratio of 2.5 ml water/gram of sorbent
material and agitated in a Burrell Shaker
for 24 hours at ambient temperature. Pre-
liminary studies revealed that saturation
of the mixture with respect to total dis-
solved solids was achieved in 24 hours.
The resultant mixture was then filtered us-
ing a glass fiber filter (Reeve Angel type
934A) in order to remove all undissolved
and non-filterable solids. The filtrates
(leachates) were then stored in plastic
screw cap bottles at ambient temperature
until used.
Preparation of Sludge Leachates
A sample of each type of sludge was
dried at 103°C to determine its moisture
content. The unaltered sludge was then
mixed with deionized water in a ratio of
2.5 ml water per gram of dried sludge (as
determined by the above moisture content
consideration) and mechanically stirred for
24 hours. The above ratio was selected
after a series of trial ratios involving
decreasing quantities of water in the mix-
163
-------
ture indicated that maximum sludge leachate
concentrations were achieved. At the end
of that time, the mixture was filtered
through a glass fiber (Reeve Angel type
934A). The resultant filtrate was stored
in a screw-capped plastic bottle at ambient
temperature until used.
Batch Studies
Into a tared 1 liter screw-capped
polypropylene Erlenmeyer flask was weighed
100 grams of dried sorbent materials. To
this was added 250 ml of sludge leachate.
The flask was sealed and agitated for 24
hours at ambient temperature. At the end
of this time, the mixture was filtered
through a glass fiber filter and the fil-
trate stored in sealed plastic flasks at
ambient temperature until analyzed.
Dynamic Studies
In order to simulate dynamic condi-
tions, lysimeter studies were conducted
using 500 g of sorbent material, except
for activated carbon where 250 g were used.
The lysimeters were constructed of plexi-
glass tubing (5.8 cm i.d.; 0.6 cm wall
thickness; 90 cm length). The sorbent mat-
erial was packed into the lysimeter and
supported by a porous corundum disc (6.5
cm diameter; 0.6 cm thickness). Leachate
was permitted to flow through the sorbent
material maintaining a constant hydraulic
head. Samples were then collected at regu-
lar time intervals and analyzed for speci-
fic parameters.
Sources of Sorbent Materials
(1) Zeolite: This material is from the
Buckhorn New Mexico Mine and was sup-
plied by Double Eagle Petroleum and
Mining Company, Casper, Wyoming.
(2) Cullite: (Hl-capacity Cullite; 16-40
mesh; white particles) supplied by
Culligan USA, Culligan International
Company, Northbrook, Illinois.
(3) Illite: Obtained from A.P. Green,Re-
fractory Company Morris Plant, Morris,
Illinois.
(4) Kaolinite: Supplied by Georgia Kaolin
Company, Elizabeth, New Jersey.
(5) Vermiculite: Obtained from W.R. Grace
& Co., Trenton, New Jersey.
(6) Bottom Ash and Fly Ash: Supplied by
Public Service Electric & Gas Company
Hudson Generating Station, Jersey City,
New Jersey.
(7) Activated Carbon: (Grade 718) Obtained
from Witco Chemical, Activated Carbon
Division, New York, New York.
(8) Activated Alumina: Supplied by Alcoa.
RESULTS AND DISCUSSION
Comprehensive analyses were performed
in accordance with standard methods on
leachates generated from two calcium fluo-
ride sludges, two metal finishing sludges,
and one petroleum sludge.
The parameters chosen for analysis for
each specific sludge was determined on the
basis on results obtained from emission
spectroscopic and x-ray fluorescent analy-
sis of the leachates. Analyses were initi-
ally performed for the following heavy
metals: Copper, iron, nickel, lead, zinc,
chromium and cadmium. Further analyses
were performed for calcium and magnesium
ions (which contribute to hardness in wa-
ter) and fluoride, chloride and cyanide
ions (which, if in high concentrations in
raw water supplies, could cause rejection
of same as a potential drinking water sup-
ply source).
The findings given in Tables I through
V indicate only those ions where concentra-
tion levels are such that they could be
measured by the use of atomic absorption
and specific ion equipment. Tables I
through V indicate the analyses of the
leachates generated from the above-mentioned
sludges prior to their mixing with the ten
respective sorbent materials. In addition,
the analysis of the leachate generated with
deionized water from each of the sorbent
materials was also analyzed. Upon comple-
tion of the above, batch studies were per-
formed (as described above) to develop the
following data:
1 - The sorption capability of the respec-
tive sorbent materials tested for spe-
cific constituents (in micrograms per
gram of sorbent used, or pg/g).
2 - The removal efficiency of the sorbent
material studied for those ions in the
respective sludges.
(a) Calcium Fluoride Sludges: The analysis
of the calcium fluoride sludge leach-
ates show signifigant concentrations of
calcium, magnesium, copper, fluoride,
chloride and cyanide ions (see Tables
I and II). Also, signifigant levels of
organics as represented by the COD,
164
-------
TOG measurements were observed.
In analyzing the results in terms of
micrograms removed per gram of sorbent used
it is interesting to note that those effec-
tive sorbent materials found for each spe-
cific ion studied tend to achieve approxi-
mately the same values of sorbent capacity.
Thus, the removal capacities of effective
sorbents are within a relatively close
range.
Tables VI and VII show percent remo-
vals of various sorbents for the parameters
studied. The following can be appreciated:
1 - There is no single sorbent material
which is effective in removing all mea-
sured; however, all of the parameters
with the exception of chlorides can be
effectively removed by some sorbent
material. As shown in Tables VI and
VII, a combination of two or three sor-
bent materials can virtually remove all
objectionable ions found in the calcium
fluoride sludges.
2 - Regarding the specific ions in the
sludge leachate, namely calcium, fluo-
ride and cyanide: Of the naturally
occurring sorbents, illite and zeolite
were found to be the most effective for
fluoride removed. Among the synthetic
sorbents, activated alumina and cullite
were best able to reduce fluoride lev-
els. Illite (natural sorbent) and act-
ivated carbon (synthetic sorbent) were
the only sorbents able to effectively
reduce the leachate levels of cyanide
ion. Calcium ion removal was dramati-
cally accomplished by both of the syn-
thetic sorbents, cullite and activated
alumina. Regarding the natural sor-
bents, only zeolite achieved a signifi-
cant amount of removal.
3 - It should be pointed out that although
none of the sorbents were found to be
effective in chloride ion removal from
the calcium fluoride sludge leachate,
the levels involved in the leachate,
i.e., 78 mg/1 and 59 mg/1, are well
within acceptable levels set by the U.
S. Public Health Service (250 mg/1) for
drinking water supplies. Consequently,
the chloride levels present no problem.
(b) Metal Finishing Sludges: The analyses
of the metal finishing sludge leachates
indicate potentially high concentra-
tions of nickel, fluoride and chloride
ions. In addition, the leachates were
also analyzed for COD, TOG, calcium,
and magnesium ions.
Tables III and IV record the sorbent
capability of the various materials tested
on the sludge leachate in terms of \ig re-
moved per gram of sorbent used. Regarding
the removal efficiencies, the following
were found (see Tables VIII and IX):
1 - As in the case of the calcium fluoride
sludge leachates, there is no single
sorbent material which is effective in
removing all ions from the leachates
examined. However, with the exception
of chloride ion removal, there can be
found a combination of two or three
sorbents which may in combination ef-
fectively reduce all other ions stud-
ied.
2 - Regarding removal efficiencies, it was
found that of the natural sorbents,
only illite and kaolinite were effec-
tive in reducing fluoride leachate
levels (see Tables VIII and IX). Of
the synthetic materials, nickel ion re-
moval was effectively achieved with
activated alumina and activated carbon,
both synthetics. To a lesser extent,
the naturally occurring vermiculite and
kaolinite were also effective. Consid-
ering chloride ion removal efficiency,
only illite (natural) was found to be
moderately successful in reducing chlo-
ride levels in the leachate. In both
metal finishing sludges, the efficien-
cies achieved (36% and 39%) were suf-
ficient to reduce chloride levels to
acceptable raw water standard.
(c) Petroleum Sludge: The petroleum sludge
exhibited high COD, TOC, calcium, mag-
nesium, nickel, lead, fluoride, chlo-
ride and cyanide levels.
Table V lists the values of each para-
meter examined in terms of micrograms mate-
rial removed per gram of sorbent used.
Considering removal efficiencies of the
abovementioned parameters (see Table X) the
following was found:
1 - Of the synthetics, activated carbon was
found to be the most successful in low-
ering both COD and TOC levels in the
leachate. Illite was found to be the
most successful of the natural sor-
bents .
2 - All of the synthetic sorbents were ex-
tremely effective in removing calcium
165
-------
and magnesium ions. Moderate success
was achieved for calcium by the use of
the natural illite. None of the natu-
ral sorbents were able to appreciably
reduce magnesium ion levels.
3 - Fluoride ion removal was successfully
achieved with the use of illite (natu-
ral) , kaolinite (natural), and activa-
ted carbon (synthetic). Activated
alumina (synthetic) was effective as
well, to a lesser extent.
4 - Cyanide ion removal was best achieved
by activated carbon (synthetic) and to
a lesser extent by illite (natural).
However, only activated carbon treat-
ment was effective in reducing cyanide
leachate levels to a concentration ac-
ceptable for raw drinking water pur-
poses .
5 - Nickel ion removal can moderately be
achieved by using activated alumina as
a sorbent material. None of the other
sorbents achieved any reasonable suc-
cess in sorbing nickel ions. Fortu-
nately, the leachate nickel background
in the petroleum sludge studied was
sufficiently close to acceptable raw
drinking water standards to require
little treatment. If, however, such
background values should increase mark-
edly, further study would be required
to achieve higher removal efficiencies
by the sorbent or combinations of sor-
bents required.
6 - Lead ion reduction by all the sorbents
was virtually non-existent. Further
studies will be needed to solve this
problem.
7 - Chloride levels present a problem. Al-
though some removal can be achieved by
all of the sorbents studied (with ill-
ite and activated carbon found to be
the most effective), the high chloride
background, namely 10,990 mg/1, is so
large that percent removals in the high
ninety percentiles would be required in
order to achieve acceptable an accep-
table level of chloride ion.
In summation, lead and chloride ion
levels continue to present a problem as
shown by the initial batch studies perfor-
med on the petroleum sludge.
WORK IN PROGRESS
The abovementioned batch studies re-
present a first-cut approach at a design
for removing objectionable ions from sludge
leachates. It is appreciated by the auth-
ors that the studies described above do not
closely simulate anticipated field design
conditions nor do they consider the appli-
cation of various combination of sorbent
materials. To this end, further studies
are being conducted with the use of lysi-
meters in an attempt to more closely appro-
ximate the true conditions that sorbent
materials would be subjected to when sur-
charged with sludge leachates. Preliminary
results from these studies (as shown in
Table XI) indicate much greater removal
efficiencies with the same sorbent mater-
ials than was found in the batch studies.
Breakthrough points are being simultaneous-
ly determined during the lysimeter studies.
(Breakthrough point in these tests is con-
sidered to be the development of effluent
concentrations, for each ion tested, which
exceed acceptable raw water drinking lev-
els.)
Preliminary results indicate that some
of the sorbents tested are effective in re-
tarding breakthrough.
SUMMARY AND CONCLUSIONS
(1) There are a number of sorbent materials
(both natural and synthetic) which have
been found effective in removing objection-
able ions from industrial sludge leachates.
(2) Although no single sorbent material was
found to be effective in removing all ob-
jectionable ions from the sludge leachates
studied in general, two or three different
sorbent materials could be collectively
combined to reduce sludge leachate effluent
levels to acceptable values.
(3) Preliminary lysimeter studies indicate
that considerably higher removal efficien-
cies can be achieved than were achieved in
the batch studies using the same sorbent
materials. Considering the success indi-
cated in the batch studies, the authors are
convinced that the results of the lysimeter
studies will provide some valuable design
data for removing industrial sludge leach-
ates in the field on a cost-effective ba-
sis .
REFERENCES
1. Hughes, G.M., Landon, R.A. and Favol-
den, P.N., "Hydrogeology of Solid Waste
Disposal Sites in Northeastern Illi-
nois", Report SW-12d, U.S. Environmen-
166
-------
tal Agency, 1971.
2. Brunner, D.R. and Keller, D.J., "Sani-
tary Landfill Design and Operation",
Report No. SW-65ts, EPA, 1972.
3. Neely, G.A. and Axtz, N.S., "Demonst-
ration Sanitary Landfill in Kansas
City, Kansas", Civil Engineering-ASCE,
72, October, 1972.
4. "Sanitary Landfill in Odd,Gravel Pit",
Pollution Equipment News, page 1, Oct-
ober, 1972.
5. Witt, P.A. Jr., "Disposal of Solid
Waste", Chemical Engineering 78, 62-77
(1971).
This research was supported in part
by EPA Grant No. R803717-01-0, Industrial
Waste Treatment Laboratories, Cincinnati,
OH.
167
-------
TABLE 1. BATCH STUW RESULTS OF CALCIUM FLUORIDE (LOWER PIT) SLUDGE LEACHATE
Initial
Condition
Measured of
Parameters Leachate
PH
Conductivity
Total Dissolved
Solid(mit/l)
Total Dissolved
Volatile Solid
(ms/1)
Total Dissolved
Fixed Solid
COD (mg/1)
TOC(mg/l)
Ca(mg/l)
Cu(mg/l)
Mg(mg/l)
Cl-
Cn (mg/1)
6.3
2620
2783
329
2454
76
16.5
400.0
0.22
11.0
59
6.08
0.60
Description
Background' of Sorbent Material
Amt. Remaining After Treatment
Background of Sorbent Material
Amt. Remaining After Treatment
Background of Sorbent Material(mg/l)
Amt. Remaining After Treatment (mg/1)
ug Removed per g of Sorbent Used
Background of Sorbent Material(mg/l)
Amt. Remaining After Treatment (mg/1)
[i g Removed per g of Sorbent Used
Background of Sorbent Material(mg/l)
Amt. Remaining After Treatment (mg/1)
ug Removed per g of Sorbent Used
Amt. Remaining After Treatment(mg/l)
ug Removed per g of Sorbent Used
Background of Sorbent Material(mgA)
Amt. Remaining After Treatment(mg/l)
ug Removed jier g of Sorbent Used
Background of Sorbent Material(mg/l)
Amt. Remaining After Treatment(mg/l)
ug Removed per e of Sorbent Used
Background of Sorbent Material(mg/l)
Amt. Remaining After Treatment (mg/1)
ug Removed oer g of Sorbent Used
Background of Sorbent Material(mg/l)
Amt. Remaining After Treatment (mg/1)
Ug Removed per g of Sorbent Used
Background of Sorbent Material(mg/l)
Amt. Remaining After Treatment (mg/1)
UK Removed per e of Sorbent Used
Background of Sorbent Materlal(mg/l)
Amt. Remaining After Treatment(mg/l)
ug Removed per g of Sorbent Used
Background of Sorbent Material(mg/l)
Amt. Remaining After Treatment(mg/l)
ug Removed per g of Sorbent Used
Bottom Fly
Ash Ash
7.2
6.0
2780
5200
1853
4573
526
490
1327
4083
40
80
0
0.0
0.0
41.3
20.0
385.0
37.5
0.25
0.10
0.30
93.2
52.0
0.0
500
470
0
0.31
2.55
8.83
0.70
0.48
0.30
8.5
10.2
2500
2990
2901
3188
582
467
2319
2721
5
39
93
4.1
0.0
41.3
300.0
485.0
0.0
0.06
0.02
0.50
3.2
1.0
25.0
10
60
0
.71
2.19
9.73
0.04
0.56
0.10
Zeo- Vermi-
lite lite
7.8 8.1
7.5 7.3
8150 182
7000 2800
7224 136
9826 2925
530 30
809 422
6686 106
9017 2503
27 13
76 53
0 58
0 2.7
14.4 10.9
5.3 14.0
6.0 1.5
135.0 400.0
662.5 0.0
0.07 0.03
0.05 0.07
0.43 0.38
169.0 4.7
60.0 20.2
0.0 0,0
126 3
180 56
0 8
0.51 1.21
1.65 5.89
11.08 0.48
0.04 0.02
0.54 0.50
0.38 0.25
11-
lite
3.0
3.0
4460
4400
3985
4316
900
908
3085
3408
16
48
70
0.0
0.0
41.3
2.5
335.0
162.5
3.55
3.66
0.00
70.0
48.8
0.0
3
40
48
0.33
0.64
13.60
0.02
0.15
1.13
Kaolite
5.1
4.2
295
1980
32
3439
112
644
202
2795
7
140
0
15.5
26.0
0.0
42.0
355.0
112,5
0.16
0.29
0.00
4.9
14.0
0.0
7
50
23
2.28
3.08
7.50
1.20
1.60
0.00
Acti- Acti-
vated vated
Aluminae Aluminae Activated
(I) (II) Cullite Carbon
9.8
8.6
2790
3590
1254
2897
332
304
922
2593
24
85
0
37.6
16.3
0.5
0.75
998.1
0.04
0.02
0.50
0.1
0.6
26.0
46
89
0
2.09
1.59
11.23
0.22
0.48
0.30
9.7
9.3
3030
3670
1907
3603
555
585
1352
2718
22
98
0
76.0
45.7
0.0
< 0.1
999.8
0.03
0.07
0,38
1.1
24.8
38
91
0
2.28
1.85
10.58
0.02
0.53
0.18
9.0
7.9
4010
1660
3296
5130
391
465
2905
4665
21
87
0
40.1
17.5
0.0
999.8
0.42
0.31
0.00
0.2
3.0
20.0
7
61
0
0.30
2.02
10.15
0.02
0.60
0.00
9.4
9.9
575
2280
426
2924
10
260
416
2664
2
185
5.1
5.1
28.5
0.5
327.0
182.5
0.03
0.06
0.40
•^0.1
1.5
23.8
5
75
0
0.04
4.85
3.08
0.02
0.10
1.25
Acceptable
Raw Water
Standard
500
MA
NA
NA
NA
NA
NA
NA
250
1.5
0.20
168
-------
Table II. Batch Study Results of Calcium Fluoride (Upper Pit)
.Sludge Leachate
Measured
pH
Conductivity
Total Dissolved
Solid Cr.6/1)
Total Dissolved
Volatile Solid
frs/l)
Tocal Dissolved
Fixed Solid
(ne/l>
COD (mg/l)
TOO (ffig/1)
Ca (mg/l)
CU (lDg/1)
Mg (mg/l)
F" (mg/1)
Cl" (ng/1)
c:i" ds/l)
Initial
Condition
of
Leachate
7.5
3080
3390
537
2853
89
8.5
365.0
0.49
5.0
5.89
78
0.42
Description
Background of Sorbent Material
Amt. Remaining After Treatment
Background of Sorbent Material
Ant. Remaining After Treatment
Amt. Remaining After Treatment (mg/l)
Background of Sorbant Material (mg/l)
Ant. Remaining After Treatment (mg/l)
Background of Sorbent Material (mg/l)
Amt. Remaining After Treatment (mg/l)
Background of Sorbent Material (mg/l)
Amt. Remaining After Treatment (mg/l)
yg Removed per g of Sorbent I'sed
Background of Sorbent Material (mg/l)
Amt. Remaining After Treatment (mg/l)
Background of Sorbent Material (mg/l)
Arat. Remaining After Treatment (rag/1)
yg Removed per g of Sorbent Used
Background of Sorbent Material (mg/l)
ug Removed j>er g of Sorbent Used
Background of Sorbent Material (mg/l)
Amt. Remaining After Treatment (mg/l)
yg Removed per g of Sorbent Used
background of Sorbent Material (mg/l)
Ant. Remaining After Treatment (mg/l)
Background of Sorbent Material (mg/l)
yg Removed per R of Sorbent Used
Background of Sorbent Material (mg/l)
Amt. Remaining After Treatment (mg/l)
ug Removed per K of Sorbent Used
Bottom
Ash
7.2
7.1
2780
5950
1853
4848
526
581
1327
4267
40
89
0
0.0
0.0
21.3
20.0
261.0
260.0
0.03
0.20
0.73
93.2
96.6
0.0
0.31
2.49
8.50
500
482
0
0.07
0.47
0.00
Fly
Ash
8.5
8.9
2500
3410
2901
3262
582
328
2319
2934
5
52
93
4.1
0.0
21.3
300.0
365.0
0.0
0.06
0.16
0.83
3.2
3.3
4.3
1.71
2.28
9.03
10
88
0
0.35
0.50
0.00
Zeolite
7.8
7.6
8150
11550
7224
10189
530
603
6686
9586
27
94
0
0.0
8.3
0.5
6.0
88.0
692.5
0.07
0.20
0.73
169
174
0.0
0.51
2.09
9.50
126
195
0
0.04
0.44
0.00
Vermlcullte
8.1
7.3
182
3200
136
3324
30
467
106
2857
13
67
55
2.7
8.0
1.3
1.5
318.0
117.5
0.03
0.29
0.50
4.7
9.7
0.0
1.21
5.38
1.28
3
80
0
0.02
0.43
0.00
mite
' 3.0
3.2
4460
4150
3785
4425
900
667
3085
3758
16
40
123
0.0
0.0
21.3
2.5
300.0
162.5
3.55
3.75
0.00
70.0
75.0
0.0
0.33
0.91
12.50
3
'70
20
0.02
0.16
0.65
Kaollnlte
5.1
5.2
295
2680
32
3321
112
404
202
2917
7
90
0
15.5
18.5
0.0
42
231
335.0
0.16
0.60
0.00
4.9
9.9
0.0
2.28
3.50
5.98
7
74
10
1.20
1.11
0.00
Activated
Alumina
(I)
9.8
8.7
1790
4150
1254
3037
•332
308
922
2731
24
98
0
37.6
8.3
0.5
<0.1
0.1
912.3
0.04
0.21
0.70
0.1
0.2
12.0
2.09
1.25
11.60
46
95
0
0.22
0.52
0.00
Activated
Alumina
(II)
9.7
8.4
3030
5050
1907
3631
555
442
1352
3189
22
110
0
76.0
40.7
0.0
<0.1
5.0
900.0
0.03
0.23
0.65
<0.1
1.7
8.3
2.28
1.65
10.60
38
110
0
0.20
0.58
0.00
Culllte
9.0
8.0
4010
5000
3296
3697
391
243
2905
3454
21
96
0
40.1
10.3
0.0
<0.1
0.3
911.8
0.42
0.42
0.18
0.2
0.4
11.5
0.30
1.94
9.88
7
84
0
0.02
0.42
0.00
Activated
Carbon
9.4
8.5
575
2510
426
2875
10
224
416
2651
<2
<2
218
5.1
5.1
8.5
-0.5
1.1
909.8
0.03
0.08
1.03
<0.1
1.1
9.8
0.04
4.85
2.60
5
67
22.5
0.02
0.10
8.00
Acceptable
Raw Water
Standard
500
KA
KA
NA
SA
MA
1.0
XA
1.5
250
0.20
-------
Table III. Batch Study Results of Metal Finishing. Vacuum Filter Sludge Leachate
Measured
Parar-ecers
j/ri
Cond'jctivity
Total Dissolved
Solid (mg/1)
VolatiJe Solid
fr.e/1)
To:^l Dissolved
Fixed Solid
0»R/1)
COD
TOC
Ca (ng/1)
Kg (mS/l)
Xt (ng/1)
F~ (mg/1)
cr
Initial
Condition
of
Leachate
8.9
2000
1824
516
1308
97
39.9
6.5
18.0
0.15
1.20
125
Description
Aitt. Regaining After Treatment
Background of Sorbent Material
Ant. Regaining After Treatment
Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (mg/1)
ug Removed per g of Sorbent Used
Background of Sorbent Material (mg/1)
ug Penoved per g of Sorbent Used
Background of Sorbent Material (mg/1)
Amt. Renaining After Treatment (mg/1)
yg Removed per g of Sorbent Used
Background of Sorbent Material (mg/1)
ug Removed_per g of Sorbent Used
Background of Sorbent Maceria] (ng/1)
Arac. Renaining After Treatment (mg/1)
yg Removed per g of Sorbent Used
Background of Sorbent Material (mg/1)
Amt. Renaining After Treatment (mg/1)
yg Removed per g of Sorbent Used
Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (mg/1)
yg Removed per g of Sorbent Used
Background of Sorbenc Material (mg/1)
Amt. Remaining After Treatment (rag/1)
yg Removed per g of Sorbent Used
Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (mg/1)
yg Removed per g of Sorbent Used
Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (mg/1)
Bottom
Ash
7.2
8.7
2780
3750
1853
2770
526
416
1327
2354
40
97
0
0.0
8.6
78.3
20.0
22.0
0.0
93.2
42.0
0.0
<0.05
0.12
0.08
0.31
1.44
0.00
500
510
0
Fly
Ash
8.5
9.3
2500
2990
2901
3724
582
377
2319
2897
5
58
98
4.1
23.3
41.5
300.0
295.0
0.0
3.2
17.0
2.5
<0.05
0.08
0.18
1.71
1.44
0.00
10
135
0
Zeolite
7.8
8.2
8150
8750
7224
8158
530
658
6686
7500
27
109
0
0.0
32.8
17.8
6.0
10.0
0.0
169.0
53.0
0.0
<0.05
0.16
0.00
0.51
1.75
0.00
126
245
0
Verrfiicullte
8.1
8.5
182
1185
136
1189
30
286
106
903
13
77
50
2.7
20.6
48.3
7.5
7.1
0.0
4.7
20.0
0.0
<0.05
0.08
0.18
1.21
1.81
0.00
3
105
50
Illite
3.0
3.4
4460
3720
3985
4276
900
668
3085
3608
16
50
118
0.0
3.1
92.0
2.5
2.6
9.8
70.0
48.0
0.0
0.65
0.68
0.00
0.33
0.34
2.15
3
76
123
Kaolinite
5.1
7.1
295
1075
32
1231
112
428
202
803
7
122
0
15.5
42.1
0.0
42.0
42.0
0.0
4.9
2.0
40.0
<0.05
0.05
0.25
2.28
0.34
2.15
7
95
75
Alumina
(I)
9.8
9.4
1790
2290
1254
1751
332
427
922
1324
24
132
0
37.6
61.6
0.0
<0.1
0.17
15.8
0.1
0.2
44.5
<0.05
0.75
0.00
2.09
1.96
0.00
46
170
0
Alumina
(II)
9.7
9.6
3030
2900
1907
2540
555
884
1352
1656
22
133
0
76.0
112.6
0.0
<0.1
<0.1
16.0
0.1
0.1
44.8
<0.05
0.05
0.25
1.21
1.29
0.00
36
160
0
Cullite
9.0
9.5
4010
2100
3296
4364
391
894
2905
3470
21
138
0
40.1
63.7
0.0
<0.1
<0.1
16.0
0.2
0.8
43.0
<0.05
0.20
0.00
0.30
0.43
1.93
7
130
0
Activated
Carbon
9.4
9.9
575
1700
426
1418
10
245
416
1173
<2
<2
238
5.1
5.1
87.0
5.1
1.7
12.0
0.5
2.9
37.8
<0.05
<0.05
0.25
0.04
0.97
0.58
2
130
0
Acceptable
Raw Water
Standard
500
NA
NA
NA
HA
KA
NA
NA
1.5
250
-------
Table IV. Batch Study Results of Metal Finishing (Settling Tank) Sludge Leachate
Parameters
pH
Conductivity
local Dissolved
Solid (ag/1)
Total Dissolved
Volatile Solid
(**/!>
Total Dissolved
Fixed Solid
(r.jj/1)
COD (mg/1)
TOC (cg/1)
Ca (mg/1)
Mg (lg/1)
Nl (mg/1)
P" (mg/1)
Cl" (mg/1)
Initial
of
Leachate
8.8
1670
1835
673
1162
402
156.6
13.5
20.0
0.12
1.44
360
Description
Background of Sorbent Material
Amt. Remaining After Treatment
Background of Sorbent Material
Amt. Remaining After Treatment
Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (rag/1)
Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (mg/1)
Background of Sorbeut Material (mg/1)
Amt. Remaining After Treatment (ing/1)
Background of Sorbent Material (mg/1)
Ant. Remaining After Treatment (mg/1)
pg Removed per g of Sorbent Used
Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (mg/1)
ug Removed per g of Sorbent Used
Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (mg/1)
pg Removed per g of Sorbent Used
Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (mg/1)
Ug Removed per g of Sorbent Used
Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (mg/1)
P£ Removed per g of Sorbent Used
Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (mg/1)
pg Removed per g of Sorbent Used
Amt. Remaining After Treatment (mg/1)
yg Removed per a of Sorbent Used
Bottom
Ash
7.2
8.5
2780
3900
1853
2871
526
368
1327
2503
40
324
195
0.0
136.7
49.8
20.0
25.0
0.0
93.2
46.0
0.0
<0.05
0.15
0.00
0.31
1.68
0.00
500
700
0
Fly
Ash
8.5
9.0
2500
3000
2901
3948
582
854
2319
3074
5
350
130
4.1
149.1
18.8
300.0
305.0
0.0
3.2
4.0
40
<0.05
0.10
0.05
1.71
1.62
0.00
10
375
0
Zeolite
7.8
8.3
8150
7500
7224
8311
530
442
6686
7869
27
127
688
0.0
53.2
258.5
6.0
15.0
0.0
169.0
54.0
0.0
<0.05
0.16
0.00
0.51
1.90
0.00
126
425
0
Vennicullte
8.1
8.6
182
1360
136
I486
30
522
106
964
13
189
533
2.7
151.3
13.3
1.5
8.0
13.8
4.7
15.0
12.5
<0.05
0.08
0.10
1.21
2.03
0.00
3
360
0
Illlte 1
" 3.0
3.1
4460
4700
3985
5144
900
1349
3085
3795
16
114
720
0.0
18.9
344.3
2.46
2.55
0.0
70.0
51.0
0.0
0.65
0.68
0.00
0.03
0.35
2.73
3
230
325
taollnlte
5.1
7.6
295
1370
32
1365
112
317
202
1048
7
214
470
15.5
59.9
241.8
42
35
0.0
4.9
3.0
42.5
<0.05
0.08
0.10
2.26
0.49
2.38
7
345
38
Alumina
(I)
9.8
10.3
1790
2390
1254
332
922
24
400
5
37.6
195.0
0.0
<0.1
<0.1
33.5
<0.1
0.1
49.8
<0.05
0.06
0.15
2.09
1.73
0.00
46
400
0
Alumina
(II)
9.7
9.3
3030
2200
1907
3067
555
851
1352
2216
22
410
0
76.0
219.0
0.0
<0.1
<0.1
33.5
<0.1
0.1
49.8
<0.05
0.05
0.175
2.28
1.39
0.13
38
390
0
Culllte
9.0
8.9
4010
5050
3296
4936
391
950
2905
3980
21
342
150
40.1
178.8
0.0
<0.1
<0.1
33.5
0.2
O.S
48.0
<0.05
0.17
0.00
0.30
0.38
2.65
7
370
0
Activated
Carbon
9.4
9.7
575
1610
426
1498
10
253
416
1245
<2
<2
1000
5.1
5.1
143.3
0.5
2.6
27.3
0.1
7.0
32.5
<0.05
<0.05
0.175
0.04
1.12
0.8
2
177
458
Raw Water
Standard
500
KA
NA
KA
NA
NA
KA
HA
1.50
250
-------
Table V. Batch. Study Results of Bottom Tank. Petroleum Sludge Leachate
Measured
Parameters
?K
Conductivity
Total Dissolved
Sclid Jca/1)
Total Dissolved
Volatile Solid
(r.a/1)
Tocal Dissolved
(ng/l)
COD (Glg/1)
TOC (mg/1)
Ca (mg/i)
Mg (mg/1)
N'l (ng/1)
Pb (mg/1)
an (mg/1)
P" (ng/1)
Cl" (ng/1)
O- (mg/1)
Initial
Condition
of
Leachate Description
7.4 Background of Sorbent Material
Ant. Retraining After Treatment
15000 Background of Sorbent Material
Amt. Remaining After Treatment
Background of Sorbent Material (mg/1)
Background of Sorbent Material (rag/1)
Amt. Remaining After Treatment (mg/1)
Background of Sorbent Material (mg/1)
1299 Background of Sorbent Material (rag/1)
Amt. Remaining After Treatment (rag/1)
Ug Removed per g of Sorbent Used
488.0 Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (rag/1)
327.0 Background of Sorbent Material (mg/1)
ug 3e-.oved per g of Sorbent Used
400.0 Background of Socbent Material (mg/1)
Arat. Remaining After Treatment (mg/1)
UK Removed per g of Sorbent Used
0.23 Background of Sorbent Material (mg/1)
Anc. Remaining After Treatment (rag/1)
0.48 Background of Sorbent Material (mg/1)
Amt. Remaining After Treatment (rag/1)
UK Removed per e of Sorbent Used
.06 Background oE Sorbent Material (mg/1)
Amt. Remaining After Treatment (mg/1)
ug Removed per g of Sorbent Used
1.48 Background of Sorbent Material (mg/1)
ug Removed per g of Sorbent Used
Amt. Remaining After Treatment (rag/1)
7/93 Background of Sorbent Material (mg/1)
Ant. Remaining After Treatment (mg/1)
" " ' ' »2 Removed per g of Sorbent Used •
Bottom
Ash
7.2
8.3
2780
14800
1853
16935
526
2214
1327
14721
40
1048
628
0.0
365.0
207.5
20.0
342.0
0
93.2
438.0
0.0
<0.05
0.24
0.00
<0.20
0.61
0.0
0.01
0.03
0.08
0.31
0.89
1.48
500
6736
0.07
2.94
12.48
Fly
Ash
8.5
9.1
2500
14200
2901
15163
532
1571
2319
13592
5
1048
628
4.1
358.0
225.0
300.0
327.0
0
3.2
397.0
7.5
<0.05
0.19
0.10
0.30
0.48
0.0
0.01
0.03
0.08
1.71
1.26
0.55
10
6204
0.04
4.94
7.48
Zeolite
7.8
8.1
8150
19000
7224
22730
530
2107
6686
20623
27
1018
703
0.0
378.0
175.0
6.0
327.0
0
169.0
356.0
110.0
<0.05
0.24
0.00
0.30
0.78
0.0
0.03
0.04
0.05
0.51
1.00
1.20
126
6736
0.04
2.99
12.35
Vermiculite
8.1
8.4
182
8400
136
15012
30
1429
106
13583
13
1014
713
2.7
367.0
202.5
1.5
330.0
0
4.7
390.0.
25.0
<0.05
0.21
0.05
<0.20
0.50
0.0
<0.01
0.03
0.05
1.21
1.43
0.13
3
6027
0.02
3.38
11.38
Illlte
3.0
3.2
4460
14JOO
3985
16100
900
244
3085
13856
16
648
1628
0.0
201.0
617.0
2.5
161.0
41 5. 0
70.0
372.0
70.0
0.65
0.79
0.00
0.33
0.59
0.0
1.46
1.50
0.00
0.33
0.22
3.15
3
3084
19675
0.02
1.38
16.38
Kaollnite
5.1
7.4
295
13600
32
14506
112
1398
202
13108
7
1113
465
15.5
363.0
212.5
42.0
315.0
30.0
4.9
385.0
37.5 .
<0.05
0.25
0.00
<0.20
0.43
0.13
0.27
0.20
0.00
2.28
0.17
3.28
7
4077
17283
1.20
5.33
6.50
Alumina
(I)
9.8
9.4
1790
13200
.1254
12214
332
624
922
11590
24
1069
575
37.6
347.0
252. 5
<0.1
2.4
811.5
<0.1
1.6
996.0
<0.05
0.13
0. 50
<0.20
0.43
0.13
<0.01
0.02
0.10
2.09
0.44
2.60
46
6382
11520
0.22
5.33
6.50
Alumina
(II)
9.7
9.1
3030
13900
1907
12864
555
498
1352
12366
22
1144
388
76.0
397.0
127.5
<0.1
.7
815.8
<0.1
5.0
987.5
<0.05
0.13
0.50
<0.20
0.43
0.13
<0.01
0.02
0.10
2.28
0.49
2.48
38
4963
15068
0.20
7.15
1.95
Acceptable
Activated Raw Water
Cullite Carbon Standard
9.0
9.2
4010
16000
3296
20409
391
1175
2905
19234
21
1131
420
40.1
405.0
107.5
<0.1
21.0
765.0
0.2
39.0
902.5
<0.05
0.22
0.03
<0.20
0.43
0.13
0.08
0.04
0.05
0.30
0.86
1.55
7
5495
13/38
0.02
7.15
1.95
9.4
9.6
575
13300
426
15085
10
1081
416
14004
<2
105
2985
5.1
26.0
1055.0
0.5
36.0
727.5
<0.1
213.0
467.5
<0.05
0.17
0.15
<0.20
0.48
0.0
<0.01
0.02
0.10
0.04
0.17
3.28
5
2801
20473
0.02
0.30
19.08
500
KA
MA
KA
!JA
KA
NA
HA
SA
5.0
1.5
250
0.20
-------
Table VI. Percentage of Removal - Calcium Fluoride Sludge (Lower Pit) Leachate
Sorbent Materials
Measured
Parameters
COD
TOC
Ca
Cu
Mg
F~
Cl~
CN~
Bottom
Ash
0
100
4
55
0
58
0
20
Table
Fly
Ash
49
100
0
91
91
64
0
7
Zeolite
0
13
66
77
0
73
0
10
VII. Percentage
Vermiculite Illite
30
34
0
68
0
3
14
17
of Removal
Percentage
37
100
16
0
0
90
32
75
- Calcium
Kaolinite
of Removal
0
0
11
0
0
49
15
0
Activated
Alumina
(I)
0
1
100
91
95
74
0
20
Activated
Alumina
(ID
0
0
100
68
90
70
0
12
Cullite
0
0
100
0
73
67
0
0
Activated
Carbon
185
69
18
73
86
20
0
83
Fluoride Sludge (Upper Pit) Leachate
Sorbent Materials
Measured
Parameters
COD
TOC
Ca
Cu
Mg
F~
Cl~
CN~
Bottom
Ash
0
100
29
59
0
58
0
0
Fly
Ash
42
100
0
67
34
61
0
0
Zeolite
0
2
76
59
0
65
0
0
Vermiculite Illite
25
6
13
41
0
9
0
0
Percentage
55
100
18
0
0
85
10
62
Kaolinite
of Removal
0
0
37
0
0
40
5
0
Activated
Alumina
(I)
0
2
100
57
96
79
0
0
Activated
Alumina
(ID
0
0
99
53
66
72
0
0
Cullite
0
0
100
14
92
67
0
0
Activated
Carbon
98
40
100
84
78
18
14
76
-------
Table VIII. Percentage of Removal of Metal Finishing (Vacuum Filter) Sludge Leachate
Sorbent Materials
Measured
Parameters
COD
TOC
Ca
Mg
Ni
F~
Cl~
Measured
Parameters
COD
TOC
Ca
Mg
Ni
F~
Cl~
Bottom
Ash
Fly
Ash Zeolite Vermiculite
Illite
Kaolinite
Activated Activated
Alumina Alumina Activated
(I) (II) Cullite Carbon
Percentage of Removal
0
79
0
0
20
0
0
Table
Bottom
Ash
40 0
42 18
0 0
6 0
47 0
0 0
0 0
IX. Percentage
Fly
Ash Zeolite
21
48
0
0
47
0
16
of Removal
49
92
60
0
0
72
39
of Metal
Sorbent
Vermiculite Illite
0
0
0
89
67
72
24
Finishing
Materials
Kaolinite
0 0
0 0
97 99
99 99
50 67
0 0
0 0
(Settling Tank) Sludge
Activated Activated
Alumina Alumina
(I) (ID
0
0
100
96
0
64
0
Leachate
98
87
74
84
67
19
0
Activated
Cullite Carbon
; Percentage of Removal
19
13
0
0
0
0
0
13 68
5 66
0 0
80 0
17 0
0 0
0 0
53
3
41
25
33
0
0
72
88
0
0
0
76
36
47
62
0
85
33
66
4
0 0
0 0
99 99
100 100
50 58
0 4
0 0
15
0
99
96
0
74
0
100
97
81
65
58
22
51
-------
Table X. Percentage of Removal - Tank Bottom Petroleum Sludge Leachate
Sorbent Material
Measured
Parameters
COD
TOG
Ca
Mg
N±
Pb
Zn
F~
Cl~
CN~
Bottom
Ash
19
25
0
0
0
0
50
40
39
63
Fly
Ash
19
27
0
1
17
0
50
15
44
38
Zeolite
22
23
0
11
0
0
33
32
39
63
Vermiculite
22
25
0
3
9
0
50
4
45
57
Illite Kaolinite
Percentage
50
59
51
7
0
0
0
85
72
83
Activated
Alumina
(I)
Activated
Alumina
(ID
Cullite
Activated
Carbon
of Removal
14
26
4
4
0
10
0
89
63
33
18
29
99
100
44
10
67
70
42
33
12
19
100
99
44
10
67
67
55
10
13
17
94
90
4
10
33
42
50
10
92
95
89
91
26
0
67
89
75
96
-------
Table XI. Comparisons of Removal Capacities of Fly ash in Batch
and Lysimeter Tests (Calcium Fluoride Sludge Leachate)
Batch Tests
Fly Ash
(Acidic)
Fly Ash
(Alkaline)
Lysimeter Tests
Fly Ash
(Acidic)
Fly Ash
(Alkaline)
- **
F .0103
Ca 0.0000
Cu 0.0000
Mg 0.0000
.0093
0.0000
0.0002
0.0413
0.09
0.35
> 0.0014*
0.025
>0.05*
0.00
>0.0003*
>0.105*
* Removal still in progress
** Capacities are expressed in mg of ion removal per
g of sorbent used
176
-------
PROBLEMS ASSOCIATED WITH THE LAND DISPOSAL OF AN ORGANIC
INDUSTRIAL HAZARDOUS WASTE CONTAINING HCB
by
W. J. Farmer
M. Yang
J. Letey
Department of Soil Science
and Agricultural Engineering
University of California
Riverside, CA 92502
and
W. F. Spencer
Agricultural Research Service, USDA
Riverside, California
ABSTRACT
Hexachlorobenzene (HCB) is a persistent, water-insoluble, fat-soluble organic com-
pound present in some industrial wastes. Its transport in moving water would be negli-
gj.ble but its long term persistence allows significant volatilization to occur. Adequate
coverings are desired to reduce or eliminate HCB vapor movement when the wastes are
applied to land. Research was initiated to determine under what conditions, if any,
it is safe to dispose of HCB-containing waste on land. The volatilization fluxes of
hexachlorobenzene from industrial wastes were determined using coverings of soil, water
and polyethylene film in a simulated landfill under controlled laboratory conditions.
Coverings of water and soil were found to be highly efficient in reducing volatilization.
Polyethylene film was less efficient when compared on a cost basis. Volatilization
flux through a soil cover was directly related to soil air-filled porosity and was there-
fore greatly reduced by increased soil compaction and increased soil water content.
An organic liquid phase associated with the hex waste was heavier than water and contained
1.4% HCB by weight. The presence of HCB in this liquid phase creates the potential
for the rapid transport of HCB in porous media.
Land disposal of industrial wastes
containing hexachlorobenzene (HCB) has
been practiced for a number of years in
the United States and elsewhere. A recent
episode of HCB contamination of beef cattle
from farms in the vicinity of a municipal
landfill receiving HCB-containing industri-
al wastes has caused concern for and a
reevaluation of present procedures in
operation at such landfills.
Hexachlorobenzene is present in indus-
trial waste as a by-product in the commer-
cial production of several chlorinated
solvents such as perchloroethylene and
carbontetrachloride (7). HCB is a regis-
tered fungicide used as a seed protection
chemical for seed grains. In addition
significant quantities of HCB are produced
as impurities or by-products in the produc-
tion of certain pesticides such as PCNP,
dacthal, mirex, simazine, atrazine, and
propazine. Industry has used several
methods to dispose of the large quantities
of hexachlorobenzene-containing waste
(hex waste). These methods include munici-
pal landfill, land burial, lagooning,
deep well injection, incineration, and
product recovery. Land disposal in muni-
cipal landfills and land burial will be
the topic of this paper. Land burial
is distinguished from municipal landfill
in that land burial is a procedure used
177
-------
by the waste manufacturer on his own pro-
perty. Lagooning is a method whereby
hex waste is temporarily stored under
water in an unlined reservoir prior to
being placed into a landfill. Hence,
this project includes the effectiveness
of a water cover in reducing volatiliza-
tion.
A typical operation where land disposal
of hex waste is used is as follows:
*
Water Admixture
(Cooling and
Precipitation)
-»
Lagoon
-t
Land
Disposal
Storage
The solid phase remaining after the water
admixture step may be either hauled dir-
ectly to the final land disposal site
or temporarily remain in a lagoon storage
site. In cases where lagoon storage is
used, the cooling and crystallization step
(water admixture) and lagooning are one
and the same. That is, the waste stream
from the production process is fed directly
below the water surface of a water lagoon.
Cooling and precipitation take place and
the solid phase stored under water in
the lagoon. Periodically, the lagoon
Ls emptied and the hex waste carried by
truck to the land disposal site.
This study was initiated because
of a specific instance of HCB contamination
of beef cattle in December, 1972 in southern
Louisiana. Beef cattle to be slaughtered
for consumption were quarantined from
sale in a 200-square mile area because
of high levels of HCB in their fat tissue.
Following extensive investigations by
local, state and federal agencies and
the cooperation of HCB-producing industries
in the area, the source of the HCB was
traced to the disposal of waste containing
HCB in a municipal landfill. Uncovered
trucks had been used to haul hex waste
from the industrial source to the landfill.
This led to spillage and contamination
along the pathways followed by the trucks.
Waste material deposited at the landfill
sites was left uncovered. It was reported
that the hex waste was being used as a
covering over municipal waste as a fly-
repellent. Disposal of hex waste in muni-
cipal landfills has ceased in affected
areas in southern Louisiana. The uncovered
waste at these landfills has been collected
into a small area of the landfill and
covered with 4 to 6 feet of soil, with
a 10-mil thick sheet of polyethyelene
film buried approximately midway in the
soil cover.
The disposal of hex waste in landfill
sites in southern Louisiana has resulted
in a pattern of HCB contamination of resi-
dents in the area, operators of the munici-
pal landfills, beef cattle, and soil,
plant and air samples (1, 6, 11, 12).
Soil and plant samples taken from near
landfill areas used for disposal of hex
waste showed decreasing HCB contents as
distance from the landfill increased (6).
Burns and Miller (1) reported
high levels of HCB in the plasma of indivi-
duals exposed through the transportation
and disposal of hex waste in southern
Louisiana. In a sampling of 29 households
situated along the route of trucks contain-
ing hex waste, the average plasma level
of HCB was 3.6 ppb with a high of 23 ppb.
The range for landfill workers was 2 to
345 ppb plasma HCB. The average plasma
HCB level in a control group was 0.5 ppb
with a high of 1.8 ppb.
Hexacholorbenzene is a stable per-
sistent compound of low water solubility
and moderate vapor pressure. It exists
as a white powder at room temperature.
Its empirical formula is C/-C1/- and its
structural formula is:
Hexachlorobenzene (HCB)
178
-------
HCB has a melting point of 230°C and sub-
limes at 322°C (4). Little information
is available in the literature on HCB
solubility, but it is essentially insoluble
in water. We have measured its solubility
in water to be 6.2 Ug/1. Sears and Hopke
(7) reported a vapor pressure of 2.10
x 10"5 mm Hg at 25°C for HCB. We have
measured its vapor pressure to be 1.91
x 10"5 mm Hg at 25°C. HCB is soluble
in several organic solvents such as benzene
and hexane and is soluble in fats and
oil. Hence it tends to accumulate in
the fatty tissues of animals. HCB should
not be confused with the organochlorine
insecticide lindane which is hexachloro-
cyclohexane (CgHgClg) even though it has
the common name BHC for benzene hexachlo-
ride.
Based on the pattern of HCB contamina-
tion of soils and plants in the Louisiana
incident, its moderate vapor pressure,
low water solubility, and long-term persis-
tence, it was concluded that volatilization
and subsequent transport by moving air
currents would be the principle mechanism
by which HCB would move about the environ-
ment. Presently there has been no infor-
mation to indicate that significant degra-
dation of HCB occurs in the environment.
This means that HCB persists long enough
that even with its moderate vapor pressure,
significant quantities can escape into
the atmosphere and can be redistributed
by moving air currents.
Therefore, research was initiated
on the volatilization of HCB from hex
waste disposed of on land. Similar disposal
problems could be expected with any waste
material containing organic compounds
of moderate vapor pressure and persistence
deposited on land and the results of this
investigation would be expected to apply
to these compounds as well. The objective
of this study was to determine the condi-
tions, if any, under which it is safe
to dispose of HCB on land. The effectiveness
of various coverings - soil, water, poly-
ethylene film - in reducing HCB volatiliza-
tion from land was specifically investiga-
ted. In pursuing this objective it was
assumed that vapor phase movement to the
soil surface and subsequent volatilization
from the soil surface is the only pathway
by which HCB moves. For detailed discussions
of factors affecting the volatilization
of organic compounds from soils and on
vapor phase movement in soils the reader
is referred to recent review articles
by Spencer, Farmer, and Cliath (10) and
Letey and Farmer (5).
SIMULATED LANDFILL
In order to determine the effectiveness
of various coverings on the volatilization
of HCB from industrial waste, the simulated
landfill apparatus as depicted in Figure 1
FLOW
METER
Figure 1. Closed air flow system for
collecting volatilized HCB from
simulated landfill.
was constructed and operated under labora-
tory conditions so that critical factors
such as temperature and air flow rate
could be closely controlled and monitored.
The soil used for the volatilization
experiments had been collected from a
municipal landfill in Louisiana where
industrial hazardous waste containing
HCB had been previously deposited. The
soil was a silty clay loam with an organic
matter content of 1.4% and a field bulk
density of 1.2 g/crn-^. Samples of hex
waste to be used in the simulated landfill
apparatus were collected directly from
two separate manufacturers of chlorinated
solvents. Hex waste samples A and B, as
collected from the manufacturer, contained
54.9% and 56.9% HCB, respectively. The samples
were air-dried at room temperature before
being used in the simulated landfill.
After air drying the HCB contents of samples
A and B increased to 65.7% and 90.5% HCB,
respectively. A third material used in
the volatilization experiment was recrys-
tallized practical grade HCB which was
98+% hexachlorobenzene. We found no dif-
ferences in the volatilization of HCB
from these materials in the simulated
179
-------
landfill. That is, HCB volatilized from
all the materials as if they were pure
HCB. (There was one exception to this
which occurred with the use of the waste
without air drying. In this case the
presence of a reddish-brown liquid in
the samples caused more rapid HCB loss
as will be discussed later.)
The volatilization cell consisted
of plexiglass sections bolted together
with 0-ring seals between the sections.
Hex waste was placed in the bottom section
and soil or other coverings placed in
the section above the hex waste. The
cover or top section of the volatilization
cell contained a cavity 2 mm deep which
allowed air flow over the surface of the
covered hex waste. An air flow rate of
0.769 I/minute was used in this study
which provided an air speed across the
soil surface of 21.5 cm/sec (0.48 mile/hr).
The apparatus utilized a closed air flow
system with the volatilized HCB collected
in hexylene glycol traps in a manner simi-
lar to that used by Farmer et al. (3) to
measure the volatilization of insecticides
from soils. The entire simulated landfill
operation was carried out inside a temper-
ature-controlled cabinet maintained at
25°C. Volatilization processes are extremely
dependent on temperature due to the tem-
perature dependence of vapor pressure. The
hexylene glycol traps were changed at suit-
able intervals and the trapped HCB extracted
into hexane to be analyzed by gas liquid
chromatography using an electron capture
detector. Prior to analysis by GC most of
the samples obtained from the industrial
waste required a column cleanup on activated
neutral alumina to remove a great number
of interfering compounds which are present
in the industrial waste samples.
Sample Cleanup
Considerable difficulty was encountered
with the GC analysis of several of the vola-
tilized samples from the industrial waste.
Tailing solvent peaks, unstable base lines,
overlapping peaks, and dirty detectors were
common occurrences. The difficulties were
assumed to be caused by the presence in the
hex waste of interfering compounds which
volatilized into the air in the simulated
landfill and were extracted into the hexane
along with HCB. Certainly, one would suspect
the formation of compounds with similar
chemical and physical properties to those
of HCB during the industrial manufacturing
process. A column cleanup procedure was
developed using activated neutral alumina
to remove the interferences. Anhydrous
sodium sulfate was layered on top of the
alumina to remove any traces of water
which may have been present in the hexane
extract containing the HCB. The hexane
sample was first placed on the cleanup
column. The column was then eluted with
pure hexane followed by 10% benzene in
hexane. Essentially all of the HCB minus
the interfering compounds eluted with
the 10% benzene in hexane fraction. This
cleanup procedure was considered to be
a significant development. Essentially
no information exists in the literature
on procedures suitable for the cleanup
of industrial waste samples for analysis
by GC.
RESEARCH FINDINGS
The factors investigated for their ef-
fect on HCB volatilization included soil
compaction, soil water content, soil depth,
temperature, use of a polyethylene film
barrier, source of waste, and a water covtr.
HCB volatilization through these coverings
were compared with HCB flux from uncovered
wastes. The flux from uncovered hex waste
in the simulated landfill apparatus at
25 C and 0.769 ml/min air flow rate was
8700 ng/cm2/day.
Soil Compaction and HCB Volatilization
When in a field situation and faced
with a decision of what to do to a landfill
site to reduce volatilization of an organic
compound from a buried waste, one has a limi-
ted number of choices available. One of
these choices is whether or not to go to
the expense of compacting the soil cover
in the landfill. Soil cover is used to
reduce the volatilization of HCB. Since
HCB is almost insoluble in water, diffusion
in the vapor phase will be the major mode
of movement through soil. Soil compaction
or soil bulk density determines the porosity
of a soil and thus affects HCB vapor flux.
Data presented in Figure 2 show that HCB
fluxes from cover soil with a bulk density
of 0.96 g/cm^ (low compaction) are greater
than those from cover soil with a bulk
density of 1.15 g/cm3 (high compaction).
180
-------
320
0
10
20
30 40 50
TIME (days)
Figure 2. Effect of soil bulk density
on the volatilization of HCB from
industrial hazardous waste covered
with 1.9 cm (3/4 in.) soil.
The final soil water contents were very
close for these two experiments and the
major effect can be attributed to the
effect of bulk density on air-filled poro-
sity. Calculation of the effect of air-
filled porosity on steady state diffusion
shows that increasing relative air-filled
porosity by 34% increases HCB flux by
more than a factor of two. Similar expo-
nential effects of air-filled porosity
on vapor phase diffusion flux has been
shown for lindane (2).
Thickness of Soil Cover and HCB Volatili-
zation
Thickness of soil cover affects the
distance an HCB molecule has to travel.
The distance or pathlength determines
the concentration gradient which is the
driving force for diffusion. Thus the
flux is also affected by the soil thickness.
Figure 3 shows that HCB flux from hex
waste covered with 1.9 cm (3/4 inch) of
soil is greater than that covered with
2.5 cm (1 inch) of soil. HCB flux from
1.9 cm of soil cover reaches steady state
at about 55 days. The flux from 2.5 cm
0 10 20 30 40 50 60 70 80
TIME (days)
Figure 3. Effect of thickness of soil cover
on HCB volatilization from industrial
waste. Soil bulk density was 1.15 g/cm .
of soil cover is still increasing at 55
days. HCB flux from the thicker soil cover
will take a longer time to reach steady
state and the final steady state HCB flux
will be smaller because of the smaller
concentration gradient. Covering hex
waste with only 1.9 cm of soil reduces
HCB flux from 8700 to 120 ng/cm2/day or
by 98.6% indicating that soil is a very
effective covering material.
Soil Water Content and HCB Volatilization
To obtain maximum compaction of the
cover soil, it is often necessary to add
water to the soil while the soil is being
compacted. Natural rainfall also adds
water to the soil. The amount of water
in a soil affects the air-filled porosity,
or the pore space available for HCB vapor
diffusion, and thus affects the HCB flux.
Figure 4 shows the effect of soil water
content on HCB flux. It is clear that
HCB flux from 1.9 cm cover soil with a
water content of 16.7% is greater than
181
-------
that from cover soil of 23.5% water content.
Calculation of air-filled porosity shows
that decreasing soil water content by
6.8% (dry weight basis) increases relative
I I I 1 1 1
30 40 50
TIME (days)
Figure 4. Effect of soil water content
on HCB volatilization from industrial
waste covered with 1.9 cm (3/4 inch)
soil at bulk density of 1.19 g/cm^.
air-filled porosity by 27%, but because of
the exponential effect of air-filled porosity
on vapor diffusion, the HCB flux increases
almost two times. From previous consider-
ations of the effect of soil compaction,
it is obvious that lower soil water content
will have effects similar to that of lower
soil compaction. The lower the soil water
content of the cover soil, the more rapidly
will the HCB flux_reach steady state.
waste with 9/16 inch of water in the simu-
lated landfill apparatus reduces the flux
1000 times.
Polyethylene Film in a Soil Cover and HCB
Volatilization
Polyethylene film has been used together
with soil in a municipal landfill as a cover
for hex waste to reduce or prevent HCB vola-
tilization. As will be shown later, poly-
ethylene film is not very effective in pre-
venting HCB volatilization when in direct
contact with hex waste; however, its effec-
tiveness may differ when used between soil
layers. Figure 5 shows the effect of poly-
ethylene film on HCB volatilization flux
140 -
1.9cm soil cover plus
4 mi I polyethylene film
20 30 40
TIME (days)
Figure 5. Effect of a composite soil plus
polyethylene film cover on HCB volati-
lization from industrial waste.
Shearer et al. (9) studied llndane
diffusion in soil and observed a similar
exponential effect of soil water content
on vapor phase diffusion. Increasing
soil water content will decrease HCB vola-
tilization flux. When soil is saturated
with water it will have the same effect
as a covering of water. A water cover
was found to be very effective in preventing
HCB volatilization. Covering the hex
from hex waste covered with 1.9 cm of soil.
Four-mil polyethylene film was sandwiched
between two 0.95 cm soil layers. It is
clear that the film reduces HCB flux and
increases the time to reach maximum flux.
However, the amount of reduction is not
very large indicating that the film is
not very effective as a barrier to HCB
volatilization.
182
-------
Hex Waste Origin and HCB Volatilization
Temperature and HCB Volatilization
HCB volatilization from hex waste
taken from two different industrial sources
was studied to determine if different
sources of hex waste would have signifi-
cantly different HCB volatilization rates.
Figure 6 shows HCB fluxes from two hex wastes
covered with 1.9 cm soil. It is obvious
that there is little difference in HCB
volatilization from these two wastes. Both
hex wastes gave a steady state flux of
123 ng/cm^/day. Experiments with practical
grade HCB also gave the same steady state
HCB flux. Thus the vapor pressure of HCB
in these two hex wastes must be similar to
that in practical grade HCB.
160
140
. 120
e 100
- 80
60
40
20
-q-
10
20
30 40 50
TIME (days)
60
70 80
Figure 6. Volatilization of HCB from soil-
covered industrial waste collected from
two different manufacturers of chlorinated
solvents.
HCB saturation vapor densities from
practical grade HCB and hex waste at 15,
25, 35, and 45° C are shown in Table 1.
Table 1.
HCB saturation vapor densities from
practical grade HCB and hex waste
at 15, 25, 35, and 45°C.
Temperature
°C
15
25
35
45
HCB
Vg/1
0.0630
0.294
0.95
3.007
Hex
V:
0
0
0
3
waste
g/1
.0686
.286
.92
.095
The vapor density of HCB at 25 C is equi-
valent to a vapor pressure of 1.91 x
10"-' mm Hg. The vapor densities from prac-
tical grade HCB and from hex waste are
essentially the same. Increasing the
temperature 10 C increases the vapor density
about three and one-half times.
Vapor diffusion rate is dependent
upon vapor density gradient and the diffu-
sion coefficient. Both vapor density
and diffusion coefficient increase with
increased temperature. Changes in vapor
density are considerably greater than
changes in diffusion coefficient as tem-
perature changes. Since HCB moves through
soil by vapor diffusion, it is reasonable
to expect that temperature effects on
HCB volatilization flux will be about
the same but somewhat greater than that
on vapor density.
Assuming similar experimental designs,
increasing temperature 10°C will increase
HCB flux about three and one-half times.
Thus, the effect of temperature on HCB
volatilization flux is exponential. Ehlers
et al. (2) studied lindane diffusion in soils
and found that a similar exponential rela-
tionship existed between temperature and
the amount of lindane diffused.
183
-------
Effectiveness of Polyethylene Film for Re-
ducing RGB Volatilization
Synthetic membranes are widely used
as barriers to liquid and gas in the land-
fill operation. The effectiveness of one
of these membranes, polyethylene film, as
a barrier to HCB volatilization was tested
in the laboratory without a soil cover.
The polyethylene film was used alone without
soil and was placed next to the waste. Fig-
ure 7 shows HCB fluxes from uncovered hex
JWWW
8000
7000
1" 6000
" 5000
O1
c
x 4000
-i
a, 3000
o
i
2OOO
IOOO
' ' ' ' ' 'O Uncovered
-
n Solvated
^ ° o 03 0 He* w°5te
//
/'
o
:
f
A II 1 III
8 10 12
TIME (days)
Figure 7. Effect of liquid phase in
hex waste on volatilization of HCB
from hex waste covered with poly-
ethylene film. Volatilization from
uncovered hex wastes is shown for
comparison.
waste and from wet (solvated) and air-dried
hex waste covered with 6 mil polyethylene
film. Polyethylene film reduces HCB fluxes
by 19% and 37% from wet and air-dried
hex waste, respectively. The film does
not seem to be very effective as a barrier
to HCB volatilization. This supports
the conclusion obtained in the section
on a composite soil and film cover that
the addition of polyethylene film to a
soil cover was not very effective in redu-
cing HCB volatilization compared to a
soil cover alone.
Problems Associated with Liquid Compo-
nents of Waste
As mentioned earlier, the wet hex
waste contained an amount of reddish-brown
organic liquid. One waste sample from
the solvent production process was found
to contain as much as 76.6% liquid by
volume. This particular sample had been
collected prior to the water admixture
step. The samples used in this study
were collected after the addition of water
to the waste stream and they contained
only a small amount of the reddish-brown
liquid. For most of the studies reported
here the hex waste samples were air-dried
to remove the organic liquid before the
initiation of the experiments. For the
data in Figure 7. the wet (solvated) hex
waste sample was filtered only and therefore
contained some reddish-brown organic liquid.
This liquid portion of the waste was ob-
served to deposit on the polyethylene
film and to cause the film to partially
dissolve and expand. The liquid waste
may thus affect the HCB transmission pro-
perty of the film. Figure 7 shows that
HCB fluxes from wet hex waste covered
with 6 mil film are greater than HCB fluxes
from air-dried hex waste covered with
the same film. Evidently, the liquid
waste caused the film to expand and resulted
in an increased HCB flux of about 28%.
Since the reddish-brown liquid waste affects
the polyethylene film causing it to partial-
ly expand, conceivably this liquid waste
may also have deleterious affects on other
synthetic membranes and thereby reduce
their effectiveness as barriers to liquid
and gas movement when used as such in
a landfill.
The liquid portions of the waste was
found to contain 1.4% HCB and have a density
of about 1.67 g/ml. Because it is heavier
than water, it may move downward when placed
in a landfill and have a potential to leach
HCB into ground water.
SUMMARY
The following comparison of HCB volati-
lization fluxes in kg/ha/yr of HCB illus-
trates the effectiveness of various cover-
ings in reducing HCB losses from industrial
wastes.
184
-------
Uncovered Waste 317 kg/ha/yr
Covered
Polyethylene film,
0.15 mm 201
Soil, 1.9 cm 4.56
Water, 1.43 cm 0.38
Soil (calculated),
120 cm 0.066
The above results are for soil collected
from the landfill site and packed to a
bulk density of 1.19 g/cnP with a water
content of 17% by weight. The volatiliza-
tion flux through the 120 cm of soil was
calculated assuming diffusion in the vapor
phase as the mechanism of movement. All
other values were measured.
The effectiveness of the materials
is water > soil > polyethylene film.
(Polyethylene film is approximately as
•effective as water in reducing HCB flux
when compared on an equal layer thickness.
The cost of polyethylene film, however,
•precludes its use in thick layers.) In-
creasing soil bulk density and/or water
content decreases HCB flux through soil.
Increasing the layer thickness of all
materials decreases HCB flux proportionally
to the increase in thickness.
5. Letey, J., and W. J. Farmer. 1974.
Movement of pesticides in soils. In:
Pesticides in Soil and Water. Guenzi,
W. D. (ed.). Madison, Wise., Amer.
Society of Agronomy, pp. 67-98.
6. Louisiana Air Control Commission and
Louisiana Division of Health, Main-
tenance and Ambulatory Patient Ser-
vices: Summary of sampling results
for hexachlorobenzene in Geismar,
Louisiana, vicinity. New Orleans,
loose-leaf publication, Aug. 5, 1973.
7. Quinlivan, S., M. Ghassemi, and M.
Santy. 1976. Survey of methods used
to control wastes containing hexa-
chlorobenzene, U. S. Environmental
Protection Agency, Office of Solid
Waste Management Programs, Washing-
ton, D.C. (in press).
8. Sears, G. W., and E. R. Hopke. 1949.
Vapor pressures of naphthalene, anthro-
cene, and hexachlorobenzene in a low
pressure range. J. Amer. Chem. Soc.
71:1632-1634.
9. Shearer, R. C. , J. Letey, W. J. Farmer,
and A. Klute. 1973. Lindane diffu-
sion in soil. Soil Sci. Soc. Amer.
Proc. 37:189-193.
REFERENCES
1. Burns, J. E., and F. E. Miller. 1975.
Hexachlorobenzene contamination: Its
effects in a Louisiana population.
Arch. Environ. Health 30:44-48.
2. Ehlers, Wilfried, W. J. Farmer, W. F.
Spencer, and J. Letey. 1969. Lindane
diffusion in soils: II. Water content,
bulk density, and temperature effects.
Soil Sci. Soc. Amer. Proc. 33:505-508.
3. Farmer, W. J., K. Igue, W. F. Spencer,
and J. P. Martin. 1972. Volatility
of organochlorine insecticides from
soil: I. Effect of concentration,
and J. P. Martin. 1972. Volatility
of organochlorine insecticides from
soil: I. Effect of concentration,
temperature, air flow rate, and vapor
pressure. Soil Sci. Soc. Amer. Proc.
36:443-447.
4. Handbook of Chemistry and Physics.
1973. R. C. Weast, editor. 53rd ed.
CRC Press, Inc., Cleveland, Ohio.
10. Spencer, W. F., W. J. Farmer, and
M. M. Cliath. 1973. Pesticide volati-
lization. Chapter in Residue Reviews.
Vol. 49:1-47.
11. U. S. Department of Agriculture News
Release No. 1105-73, Washington, D.C.
1973.
12. U. S. Environmental Protection Agency,
Open Public Hearing of the Environmen-
tal Hazardous Materials Advisory Commit-
tee Meeting chaired by E. Mrak. Aug. 6-
7, 1973. Washington, D.C.
185
-------
A PRELIMINARY EXAMINATION OF VINYL CHLORIDE EMISSIONS FROM
POLYMERIZATION SLUDGES, DURING HANDLING AND LAND DISPOSAL
R. A. Markle, R. B. Iden, and F. A. Sliemers
Battelle, Columbus Laboratories
505 King Avenue
Columbus, Ohio 43201
ABSTRACT
Vinyl chloride monomer (VCM) is retained in sludge wastes produced during polyvinyl
chloride (PVC) processing at production plants. Industry is actively investigating pro-
cessing improvements that may reduce the amount of VCM in these sludges in the future and
is looking at alternate disposal and recycle schemes. However, the PVC sludges currently
being disposed of at landfills may still contain sufficient VCM to constitute a potential
health hazard when the gaseous VCM escapes. In a preliminary, low-level study done to
determine whether a potential threat to the health of landfill workers or nearby residents
exists, 17 grab air samples were collected for laboratory analysis of VCM content at three
landfills where these sludges were disposed. Samples of the PVC sludges which were dis-
posed at the three landfills also were collected. VCM concentrations in the grab air and
sludge samples were measured using the gas chromatographlc-flame ionization detection
analytical technique. The release rate of VCM from sludge also was measured under con-
trolled laboratory conditions, using a specially designed apparatus. The VCM emissions
potential of the total sludge quantities disposed at these landfills was calculated.
INTRODUCTION
Early in 1974 it became apparent that
there was a real need to establish the level
of exposure to VCM of workers in the vinyl
chloride/polyvinyl chloride (VCM/PVC) in-
dustry. This need was triggered by reports
in January, 1974, of the deaths of four
workers in the industry believed attribut-
able to VCM exposure. Since that time angi-
osarcoma of the liver, a rare and fatal
tumor, has been identified in at least 15
workers in U.S. PVC facilities. In addition,
other forms of cancer, certain nonmalignant
liver diseases, and acroosteolysis, a unique
occupational disease, also have been found
in workers within the industry (1).
Preliminary monitoring of VCM levels in
ambient air at a number of VCM/PVC facili-
ties was then carried out by the EPA. Lev-
els ranging from <0.05 to 33 ppm were found,
with about 10 percent >1 ppm (1 to 8 ppm).
Integrated 24-hour samples generally con-
tained 1 ppm or less (1). In this same
study, measurements of VCM contained in
sludge from the polymerization process re-
actor kettles ranged from <1 to as high as
3520 ppm. It is likely that this VCM is
released into the atmosphere at the land-
fills at varying rates which depend on a
number of factors such as the nature of the
earth and debris cover under which the
sludge is buried, the temperature of the
sludge deposit, the thickness of the sludge
layer, etc. Both municipal and industrial
waste disposal sites of the dump or land-
fill type are involved in the disposal of
these industrial wastes. Thus it was de-
cided by the EPA that a need existed to
investigate VCM emissions from PVC sludges
and typical disposal sites representing a
cross section of climate conditions, dis-
posal methods, and contiguous population
densities. Consequently the present study
was initiated as a preliminary, low-level
effort, to determine approximate VCM con-
centrations in landfill air and to perform
186
-------
initial measurements, in the laboratory and
under controlled conditions, on the rates
at which VCM is released from PVC sludges.
POLYVINYL CHLORIDE PRODUCTION
PVC, commonly known as vinyl plastic,
is produced from VCM, a colorless, faintly
sweet smelling gas. VCM is converted to
solid PVC by one of four different batch
polymerization processes. U.S. PVC produc-
tion for 1974 was about 4.75 billion pounds
(2). The processes used and the percentages
of total production they represent are
listed in Table 1.
TABLE 1. PVC PROCESSES
Process
Type
Suspension
Emulsion
Bulk
Solution
Polymerization
Medium
Water
Water
Monomer
Organic Solvent
Percent of
Total PVC
Production
78
12
6
4
Regardless of the process used, a typical
PVC plant includes the following operations:
(1) Receiving and storage of VCM and
catalysts
(2) Polymerization of VCM: measuring,
charging, and reaction
(3) Stripping and recovery: reactor blow-
down and recovery, and slurry handling
and storage
(4) Centrifugation or filtration
(5) Drying
(6) Pneumatic conveying and storage
(7) Packaging and shipping
(8) Blending
(9) Waste treatment.
We are interested here only in those
steps (4 and 9) of the PVC production pro-
cess which result in by-product wastes con-
taining suspended solid matter and VCM.
Since most PVC is produced in aqueous media
(Table 1) these by-product streams consist
basically of water suspensions of fine,
particulate PVC containing small amounts of
various polymerization processing aids, and
dissolved and/or absorbed VCM. It is this
entrapped VCM which is of concern in the
present study.
The aqueous waste streams are treated
in various ways at different PVC plants.
Basically the processing consists of steps
to concentrate the solids content of the
waste as much as possible while discharg-
ing waste water of acceptable quality to
the local water treatment system, or nat-
ural outlets such as rivers. The process-
ing includes chemical treatments to co-
agulate and sediment the solids and phys-
ical separation procedures such as large,
specially designed settling and concentra-
ting tanks and specialized centrifuging
and filtration procedures. The final waste
material is a water-based sludge ranging
from about 15 to 40 percent solids. Phys-
ically these sludges range from waterlike,
thin slurries to thick pastes approximating
the consistency of a concrete premix.
These PVC sludges are industrial waste
matter which could be used or disposed of
in various ways. At the present time most,
if not all, of these sludges, are discarded
at municipal or privately owned landfills.
Typically the sludges are transported to
the landfill in pressure-controlled tank
trucks or open-bed trucks and dumped into
bulldozer-prepared pits or trenches that
are 0.6 to 3 or more meters deep. They are
then covered with compacted layers of trash
and soil to a depth of 0.3 to 1 meter or
more.
SAMPLE COLLECTION
Arrangements
At the beginning of this study three
PVC plant site/landfill combinations were
selected for sampling purposes. These
combinations were chosen to provide good
cross-sections of geographical location
and climate, PVC plant technology, sludge
type, and landfill practice. The protocol
established for sample collection included
the following steps:
(1) Visit to PVC plant by EPA and Battelle
personnel
(2) Tour of PVC sludge processing, isola-
tion, and storage facilities
(3) Observations of PVC sludge collection
by waste hauling company
(4) Collection of PVC sludge samples for
VCM analysis
(5) Follow sludge hauling truck to land-
fill with PVC company and/or hauling
company personnel
(6) Meet landfill operating personnel and
gain access to landfill
187
-------
(7) Collect background air grab sample
before PVC sludge disposal
(8) Observe PVC sludge disposal practice
(9) Collect air and sludge samples during
disposal
(10) Collect air samples after PVC sludge
disposal and coverage
(11) Collect air samples at same landfill
site approximately 1 day later.
Air Samples
Grab air samples were collected at
landfills before, during, and after sludge
disposal and coverage, downwind of the
known VCM emissions sites. The samples
were collected in preevacuated (10~8 torr
at 150 C) 3.5-liter stainless steel cylin-
ders by opening the entrance port at normal
breathing levels. The date, time, weather,
and wind conditions were recorded for each
sample taken.
Sludge Samples
During this study samples of the PVC
sludges were collected both at the plants
and at the landfills. Sludge collections
at the landfill were done during the actual
disposal operation except at Landfill 1
where sludge was collected both after dis-
posal and after bulldozing and partial cov-
erage. Sludge samples were collected in
tightly sealed glass containers to prevent
VCM evaporation, returned to the laboratory
and stored at 5°C until analysis could be
performed.
ANALYTICAL METHODS
The standard equipment used for VCM
analysis in this study was a gas chromato-
graph-flame ionization detector (GC-FID)
apparatus. Seven crosschecks were per-
formed using a mass spectrometer (MS), with
excellent agreement found. Grab air samples
were analyzed directly, by injection of air
aliquots into the GC-FID or, in one case,
the MS. Headspace and liquid phase portions
of PVC sludge samples were also analyzed by
direct injection into the GC-FID or MS. PVC
sludges were rountinely analyzed for VCM
content by extraction with tetrahydrofuran
(THF) and injection of an aliquot of the THF
extract into the GC-FID (1). One direct
analysis of a PVC sludge sample was also
performed us ing.the MS.
VCM Concentrations
VCM concentrations are expressed in
parts per million (ppm). VCM concentra-
tions in air are based on a volume ratio, or
microliters of VCM per liter of air. Thus 1
ppm equals 1 |il VCM/liter of air. However,
VCM concentrations in PVC sludges are based
on a weight ratio, or micrograms of VCM per
gram of sludge. Thus 1 ppm VCM in sludge
equals 1 |J.g VCM/gram of sludge. Consequent-
ly, ppm VCM in air cannot be compared
directly with ppm VCM in sludge. However
a one-gram sludge sample analyzing 1 ppm
VCM will yield 0.391 |il (STP) of VCM gas.
Release of the VCM in 2.56 grams of this
sludge into 1 liter of air would produce
1 ppm in air.
VCM Analysis by GC-FID
The analyses were done on a Packard
Series 800 gas chromatography instrument
using the following conditions:
Column - Porapak Q in an 8' x
3/16" stainless steel
tubing
Temperatures - Column 120°C, Detector
120°C, and Injector
120°C
Flows - Nitrogen Carrier 30 ml/
minute; Air 300 ml/min-
ute; Hydrogen 30 ml/
minute 1„
Electrometer - 500 volts; 1 x 10 amps
Sample Injection - Hypodermic syringe septa
and six way gas sam-
pling valve
Detector - Flame ionization.
The GC was calibrated using commercial
(Matheson Gas Co.) standards of VCM in
nitrogen, supplied with a certified
analysis. These were reanalyzed in our
laboratory by MS. One standard contained
20.5 ppm VCM in nitrogen and the other
0.45 ppm. The 20.5 ppm standard was used
routinely for this work.
In addition, a mixture of saturated
and unsaturated hydrocarbons including
methane, ethene, acetylene, ethane, propane,
propene, isobutane, 1-butene and n-butane
was chromatographed. Also individual sam-
ples of dichlorodifluoromethane (Freon 12),
isobutylene and 1,3-butadiene were chromato-
graphed separately. The total set of com-
pounds chromatographed and their retention
times in comparison to VCM are listed in
Table 2.
188
-------
TABLE 2. RESOLUTION OF VCM FROM
POTENTIAL CONTAMINANTS
Compound
Methane
Ethene
Acetylene
Ethane
Propene
Propane
Freon 12
VCM
Isobutane
1-butene
Isobutene
n-butane
1,3-butadiene
Formula
CH4
C2H4
C2H2
C2H6
C3H6
C3H8
CC12F2
CH2=CHC1
CH(CH3)3
CH2=CHCH2CH2
CH2=C(CH3)2
CH3CH2CH2CH3
CH2=CHCH=CH2
Retention
Time,
minutes
0.6
1.0
1.0
1.1
2.8
3.1
3.7
5.7
7.9
8.7
8.8
9.9
18.3
Freon 12 and isobutane have the near-
est retention times to VCM of the thirteen
compounds listed. However even these two
compounds show differences in retention
time of 2 minutes or longer, which is a
substantial difference resulting in total
separation of the elution peaks.
VCM Analysis by MS
The MS used for the crosscheck of the
VCM analyses was a Consolidated Electro-
dynamics Corporation Model 21-620, equipped
with a calibrated inlet system specially
designed for gas analysis. Inlet sample
pressure is measured using a micromanometer.
lonization conditions used were 50 volts at
40 milliamps. Pure VCM was used for cal-
ibration so that standardization of the GC
and MS were completely independent.
Seven MS verification analyses were
performed during this study to confirm GC
analysis of VCM. These are summarized in
Table 3.
TABLE 3. CROSSCHECK VCM ANALYSES BY MS
VCM. ppm
Sample
MS
GC-FID
1, Sludge, Vapor Phase
2, Sludge, Vapor Phase
3, Landfill Air
4, Sludge, Dry Solids
8, Plant Stream Liquid
9, Plant Stream Vapor
10, Plant Stream Vapor
2,200. 2,700.
2,300. 1,900.
0.05 0.07
210. 200.
23,000. 28,000.
8,600. 8,600.
30,900. 37,400.
DISCUSSION
In the following sections data obtain-
ed on VCM concentrations in air samples
and PVC sludge vapor, liquid and solid
phases are discussed. Also the results of
a very preliminary study of VCM release
rates from PVC sludges are discussed.
Finally a brief analysis of the VCM emis-
sions potential of the sludges is present-
ed.
Grab Air Samples
The results of laboratory analysis of
grab air samples collected at three land-
fills are listed on the following page in
Table 4.
VCM concentrations ranging from 0.07
to 1.10 ppm were found at normal breathing
levels at three landfills. At Landfill 1,
the levels found were relatively low and
the spread in concentrations was quite
small (0.07 to 0.11 ppm). At Landfill 2
concentrations ranging from 0.13 to 0.49
ppm were found while concentrations found
at Landfill 3 ranged from 0.16 to 1.10 ppm.
Three important features of these data are
noted. First, there appears to be a VCM
background level of about 0.1-0.3 ppm in
the air at all three landfills. Secondly,
instantaneous VCM concentrations as high as
about 1 ppm are on occasion observed, even
as long as 24 hours after the PVC sludge is
buried under compacted soil. The third
observation concerns an air sample which
was collected about 5 cm from a stream of
liquid sludge discharging from a truck
during landfill disposal. This air sample
was, in effect, "spiked" with extra VCM.
The fact that this particular air sample
showed an appreciably higher VCM analysis
(1.90 ppm) than the other air samples
collected at the same landfill provides
good indirect proof that the VCM peaks in
the chromatographs of landfill air are
correctly identified.
Sludge Samples
The PVC sludges were analyzed to
determine VCM contents. The vapor phase
(head space) and liquid filtrate portions
of the sludge samples were analyzed first.
It was determined that the amount of VCM
in both these phases was <10 percent of
the total VCM in all seven sludges. In
fact the VCM content of these phases was
<1 percent of the total sludge VCM content
with even moderately high total VCM
189
-------
TABLE 4. VCM CONCENTRATIONS IN GRAB AIR SAMPLES TAKEN AT LANDFILLS
Air
Sample
Number
Controls
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Temp,
°C
14
14
14
17
17
16
16
23
23
29
22
23
23
23
21
26
27
Weather
Analysis
Very cloudy
Very cloudy
Very cloudy
Very cloudy,
raining
Very cloudy,
raining
Cloudy
Cloudy
Partly cloudy
Partly cloudy
Very cloudy
Partly cloudy
Partly cloudy
Partly cloudy
Partly cloudy
Partly cloudy
Partly cloudy
Partly cloudy
Collection Information
Wind
Velocity,
kph* Sampling Location
of laboratory air grab samples
Landfill 1
0-8 30 meters from disposal site just
before sludge dump (date 4/24/75)
0-8 At leading edge of freshly dumped
sludge (4/24/75)
0-8 30 meters from disposal site after
dumping and dozing (4/24/75)
Landfill 2
5-11 At disposal site before sludge
discharge started (6/12/75)
5-11 Edge of sludge pit as soon as
discharge is completed (6/12/75)
3-11 At previous days disposal site
before fresh discharge (6/13/75)
3-11 About 5 centimeters from sludge
discharge stream (6/13/75)
0-8 Edge of sludge pit during second
dump (6/13/75)
0-8 Edge of sludge pit during third
dump (6/13/75)
8-16 180 meters inside landfill, near
sludge disposal area (8/18/75)
Landfill 3
5-11 30 meters from disposal site be-
fore sludge discharge (6/24/75)
5-11 Edge of sludge pit between two
trucks, while both are dis-
charging (6/24/75)
5-11 Same as (12) near the end of the
discharge period (6/24/75)
5-11 30 meters from disposal site after
sludge pit is covered (6/24/75)
0-8 Standing over previous days covered
disposal site (6/25/75)
0-8 Same as (15) (6/25/75)
0-8 Same as (15) (6/25/75)
VCMf,
ppm
<0.01
0.11
0.10
0.07ft
0.13
0.13
0.27
1.90
0.30
0.12
0.49
0.16
0.40
1.03
0.16
0.17
1.00
1.10
* Wind velocity in kilometers per hour measured with an anemometer.
t Gas chromatography with flame ionization detector (GC-FID).
tt This sample was also analyzed by MS as a crosscheck and 0.05 ppm were found.
190
-------
contents (^200 ppm, dry solids). Thus the
amount of VCM in these two phases is neg-
ligible in terms of potential landfill VCM
emissions.
VCM Contents of Sludge Solids
The PVC sludges were filtered and the
sludge solids subjected to VCM analysis as
described earlier. The results obtained
are shown in Table 5.
VCM concentrations found in the sludge
samples ranged from 7 to 520 ppm in the wet
filtered sludge, and from 20 to 1260 ppm on
a dry solids basis. These concentrations
can be compared with the values found in
EPA studies (1) in the spring of 1974 at six
PVC plants. In that work, VCM concentrations
found ranged from <1 ppm to 3520 ppm in wet
sludge and from <1 ppm to 4200 ppm in dry
sludge but with most of the samples contain-
ing >10 ppm on either a wet or dry basis.
Thus the VCM concentration range found in
the present work is similar to that observ-
ed in the earlier studies, although the
highest concentration level found in the
present work is about 7 times lower than
the highest values found by the EPA workers
in the spring of 1974.
VCM Release Rate Studies
Release rate studies were performed
using the apparatus shown in Figure 1.
Release rate experiments were per-
formed on PVC sludge Sample 2. This sludge
was used since the VCM concentration was in
the middle range. Release experiments were
conducted at 25°C using 13 to 15 grams of
sludge. This provided a layer about 1.3
cm deep in the release rate apparatus. In
release experiment 2 an equal thickness
layer of loam soil was placed over the
sludge. A 30 cc/minute air flow was passed
TABLE 5. VCM CONCENTRATIONS FOUND IN PVC SLUDGES
VCM
Weight
No.
1
2
3
4
5
PVC Sludge
Identification
Freshly centrifuged sludge"*"
Fresh combination sludgett
Sludge from full truckx
Sludge freshly dischared
from truck^
Sludge after disposal and
doze
Percent
As
Collected
Plant 1
34
--
35
34
36
Solids
After
Filtration
42
55
41
42
41
Concentration,*
ppm by
Wet
Sludge
150
210
520
90
90
weight
Dry
Solids
360
380
1260
200
200
Sludge collected during
discharge from truck^
Sludge collected during
discharge from truck^
Plant 2
17
Plant 3
30
40
60
90
20
130
* VCM analysis of wet (filtrated) sludge by GC-FID analysis of THF extract.
Also calculated on a dry solids basis. 360 ppm = 360 |ig/g = 0.36 mg/g =
0.036 weight percent.
t Sludge collected at PVC plant directly from centrifuge discharge tube.
tt Sludge collected at PVC plant from partly filled truck loader.
x Sludge collected at PVC plant from full truck loader.
y Sludge collected during landfill disposal.
191
-------
Thermocouple
From breathing
air lank
- S.S. med. wall
Standby Position
G.C.inlet
Sample loop
Vent
Analysis Position
Capped To detector
G.C. inlet
Sample loop
(5.28 cc)
u
Carrier gas
over the sludge. This gas flow rate is
equivalent to a no wind (calm) day at a
landfill (~ 0.002 kph wind velocity). It is
under these conditions that maximum VCM con-
centrations might be expected to accumulate
at landfills. The VCM concentrations are
instantaneous values obtained by injecting
a 5.28—cc portion of the constantly out-
flowing air into the GC apparatus. The
release rate data collected are plotted in
Figure 2.
• PVC sludge, 1.3 cm layer
o PVC sludge, 1.3 cm layer
with 1.3 cm loam soil cover
(a) Air flow 30 cc/min at 25 C
FIGURE 1. VCM RELEASE RATE APPARATUS
0
0 5 10 15 20 25 3035
VCM, pprn
FIGURE 2. VCM RELEASE RATE FROM PVC SLUDGE
The VCM release curves are similar in
form to those recently reported by Berens
(3) for dry PVC powders which consisted of
a mixture of particle sizes and types in-
cluding relatively large particles, e.g.,
40 |i fused, glassy agglomerates, even
though Berens1 work was done using very
small samples (100 to 500 mg) at very low
pressures (0-100 torr). Berens' VCM re-
lease rates, initially rapid, slowed dra-
matically in a few minutes to rates indica-
ting that times on the order of an hour or
more would be required for all VCM to be re-
leased. This was in contrast to small (4 |J.)
uniform particle size PVC powders which
yielded all absorbed VCM in 1 or 2 minutes.
This indicates that the PVC sludges may
consist mostly of relatively large PVC
192
-------
particles or fused particle agglomerates.
However the slower absolute VCM release
rates observed in the present work are
probably more due to the relatively thick
samples and the very low air flow rate
over the sludge surface.
The absolute amounts of VCM represent-
ed by the curves of Figure 2 were deter-
mined by mechanical integration of the
areas under the curves. This was done by
tracing the curves on uniform weight trac-
ing paper. The curve areas were cut out
and weighed analytically (± 0.1 mg). A
reference area was also weighed. The VCM
equivalent of a unit weight was calculated
by multiplying ordinate VCM concentration
in cc VCM/cc air by abcissa values ex-
pressed as air volumes (30 cc/min x 60 min/
hr x number of hours). Then mg VCM = (cc
VCM) (2.556 mg VCM/cc). The amounts of
VCM found are given in Table 6 expressed as
percentages of the total VCM content of the
given sludge sample.
TABLE 6. FRACTION OF VCM AVAILABLE IN
SLUDGE SAMPLES RELEASED IN
SPECIFIED TIME INTERVALS
Sludge
Run
1
2
Grams
13.6
13.3*
VCM,
mg
2.86
2.79
Percent VCM Released
Time Interval,
2
5
2
8
16
5
24
25
8
hr
110
32
11
* 1.3 cm loam soil cover.
The results obtained indicate that a
minor portion of the VCM in PVC sludge may
be quickly released at the landfill but
that a major portion of the VCM is released
very slowly over a long time period. This
means that as PVC sludge is disposed,
absolute amounts of VCM will probably con-
tinue to rise for a long, indeterminate
period until a "quasi-steady-state cond-
dition" is reached. At this point contin-
uous, slow evolution of VCM will probably
occur for a long time after sludge is no
longer disposed of at the landfill. This
conclusion is consistent with the finding
that a VCM air concentration in the range
of 0.1 to 0.3 ppm was found at each land-
fill.
VCM Emissions Potential
The VCM emissions potential of the PVC
sludges was calculated based on the VCM
concentrations in Table 5 and data supplied
by the PVC companies on the amounts of PVC
sludge being disposed of at the landfills.
The results of these calculations are
shown in Table 7.
TABLE 7. POTENTIAL VCM EMISSIONS FROM
LANDFILLS BASED ON COMPANY
SUPPLIED PVC SLUDGE DISPOSAL
RATES AND ANALYTICAL VCM
CONTENTS
PVC
Sludge
Number
PVC
Dry
Sludge
Solids
Disposal
Rate,
kg/day
Dry
Sludge
VCM
Content,
mg/kg
VCM,
Daily
Disposal Rate
kg liter*
3
4
Plant 1
4,626 0.00126 5.83 2,285
4,490 0.00020 0.90 353
Plant 2
,t
2,948' 0.00002 0.059 23
Plant 3
172
0.00013 0.022
* (kg VCM)(10 )(24.5 l/mole)/(62.5 g/mole).
t Company supplied figure - 35,000 gal/wk.
Dry solids based on 159,110 L/wk and
1.1 kg/liter.
tt Company supplied figure - 4,000 gal/mo.
Dry solids based on 18,184 L/wk and
1.1 kg/liter.
The amount of VCM being disposed of at
the landfills thus varies between 0.022
and 5.83 kg or 9 and 2,285 liters on a per
day basis. However, it is pertinent to
note that industry is actively investigat-
ing processing improvements that may reduce
the amount of VCM in these sludges in the
future and is looking at alternate disposal
and recycle schemes. This should help
reduce the VJM concentration in sludge in
the future. Unless eventual increases in
PVC production offset these future decreases
in VCM concentrations, it can be anticipated
that the total amounts of VCM being dis-
posed of will eventually decline.
193
-------
CONCLUSIONS
The following conclusions are indi-
cated by the findings of this study:
(1) A background air concentration of
about 0.1 to 0.3-ppm VCM appears to
be present in air at landfills where
PVC sludge has been disposed of for
several years.
(2) Instaneous VCM air concentrations
on the order of 1.0 ppm can occur at
normal breathing heights (~1.5 meter)
above ground level at these landfills
as long as 24 hours after PVC sludge
deposits are covered.
(3) Prevailing landfill air temperatures,
and presumably ground temperatures
as well, appear to influence VCM re-
lease rates.
(4) Time-weighted average sampling (15-
minute, 8-hour, 24-hour) is required
to determine whether concentrations
of VCM in air that pose a health
hazard occur either at the landfills
or in adjacent residential or public
access areas.
REFERENCES
(1) "Preliminary Assessment of the Envi-
ronmental Problems Associated with
Vinyl Chloride and Polyvinychloride",
Report on the Activities and Findings
of the Vinyl Chloride Task Force,
Environmental Protection Agency,
Washington, D.C., September 1974.
(2) Carpenter, B. H., "Vinyl Chloride-An
Assessment of Emissions Control
Techniques and Costs", EPA-650/2-74-
097, September 1974.
(3) Berens, A. R., "The Diffusion of
Vinyl Chloride in Polyvinylchloride",
Polymer Preprints, JL5 (2), 203-208,
1974.
ACKNOWLEDGMENTS
This work was funded by a grant from
the Solid and Hazardous Waste Research
Division, Environmental Research Laboratory,
Cincinnati, Ohio, Mr. Donald A. Oberacker,
Project Monitor.
194
-------
DISPOSAL OF WASTE OIL RE-REFINING RESIDUES
BY LAND FARMING
H.J. Snyder, Jr.
Div. of Oil & Special Materials Control
Environmental Protection Agency (WH-548)
Washington, B.C. 20460
G.B. Rice
Region VIII
Environmental Protection Agency
Denver, Colorado 80203
J.J. Skujins
Department of Soil Science & Biometeorology
Utah State University
Logan, Utah 84322
ABSTRACT
In the Spring of 1974 the Environmental Protection Agency undertook the removal and
disposal of approximately 1,700,000 gallons of residues from a waste oil re-refining
plant. The waste was stored in unsafe lagoons near Ogden, Utah, that threatened a water-
fowl refuge and was responsible for the loss of numerous migratory waterfowl that landed
in the lagoon. It was decided to dispose of the oil-water emulsion portion of the lagoon
contents in a land farm. The paper discusses the evaluation of disposal alternatives,
criteria used for selecting a suitable site, methods of applying and treating the oil-soil
system, and methods for monitoring and evaluating the project. This project was conducted
in a semi-arid area and employed supplemental fertilization. After one year, oil degra-
dation on fertilized plots approached 80 per cent.
INTRODUCTION
In the summer of 1973, Region VIII of
the Environmental Protection Agency became
aware of a serious oil pollution problem
in a makeshift lagoon near Ogden, Utah.
The lagoon was adjacent to an irrigation
return canal that flowed directly into the
Weber river delta which comprised a por-
tion of the State of Utah operated Ogden
Bay Migratory Bird Refuge. The flow from
this area then discharged into the Great
Salt Lake, three miles distant from the
lagoon. Much of the initial notoriety of
the problem involved migratory waterfowl
in the flyways to the bird refuge landing
in the oil lagoon and becoming fatally
distressed. In addition the lagoon was
constructed without any attention to safe
design and posed a potential water pollu-
tion hazard if the weakened dikes of the
lagoon failed.
The lagoon was located at the site of
a small-time marginal auto salvage yard and
contained numerous scrapped vehicles and
miscellaneous auto parts along with the
oily waste. The oily waste in the lagoon
came from an oil re-refining operation of
the Western Petroleum Company who operated
a facility in Ogden. The re-refiner was
primarily involved in reclaiming waste
195
-------
journal box and crank case oils collected
from the Union Pacific Railroad along with
waste oil collected from other local
sources. The lagoon contained residuals
from this re-refining process which con-
sisted of an acid sludge containing spent
filter clay, up to 30% unrecovered pro-
cessed oil and various amounts of lead and
engine and bearing metals which had accu-
mulated in the feed stock. Some of the
waste had been disposed of on Union Pacific
property and right-of-way in the Ogden area
prior to 1967. The remainder of the waste
was disposed of in lagoons on the re-
refiner's property in Ogden, but these
lagoons were discovered to be polluting
the nearby Weber River. In 1967, the
lagoon site in question was leased from
the auto salvage yard and a cut and fill
disposal operation began. This technique
seemed to be satisfactory for the first
nine months of operation but the waste
production from the re-refiner increased
to such a rate that they were unable to
conduct the operation in the originally
intended manner, and a lagoon then was
quickly constructed by erecting temporary
dikes across drainage lines on the property.
The lagoon was used until 1972 when the
lease on the disposal site expired and the
lagoon was then abandoned. Upon abandon-
ment the lagoon covered approximately five
surface acres contained about 1,200,000
gallons of liquid and an estimated 10,000
cubic yards of acid sludge.
The lagoon contents were in three
distinct layers. The top layer contained
750,000 gallons of a tight oil-water emul-
sion at a pH of 2.5-3.0 and a moderately
high concentration of heavy metals such as
lead which ranged from 3 to 400 tnicrograms
per gram. The middle layer was 450,000
gallons of pH 1.0-3.0 water which probably
came from surface waters and ground water
percolation at the site. The high pH was
probably due to waste sulfuric acid. The
bottom layer was a highly acid sludge of
pH 1.0 and had a very high heavy metals
concentration with lead values of 11,000
micrograms per gram.
As a result of EPA actions under sec-
tion 311 of the Federal Water Pollution
Control Act and related Federal court
orders, EPA was directed to conduct an oil
removal and disposal operation to eliminate
the pollution threats at the site. The
most perplexing part of the operation was
to be the satisfactory disposal of the
material removed from the lagoon. The
Federal On-Scene Coordinator for the pro-
ject, George Rice of EPA's Region VIII
office in Denver, conducted an exhaustive
review of disposal and/or reuse alterna-
tives. Possible reuse of the lagoon oils
for roofing materials, coking, or asphalt
yielded negative responses as did the pos-
sibility of blending with crude oil feed
stocks at local refineries. Blending with
residual oils as fuels was also considered
but concerns about low BTU values and the
requirements to capture potential air
emissions of heavy metals such as lead
discouraged this alternative. Incineration
was also examined as an alternative but the
high water content of the tight oil emul-
sion and the need for satisfactory capture
of any lead emissions resulted in this
alternative being rejected. The next obvi-
ous step was a thorough review of potential
land disposal alternatives.
One of the initial land disposal alter-
natives considered was the use of landfills.
This alternative was a difficult one
because of the high ground water table
that exists in the areas near the Great
Salt Lake. Much of the land is very low
with poor drainage and standing water dur-
ing wet seasons. The use of the oil as a
dust control agent for rural roads or as
mix with sand and gravel for such roads
was also considered but the potential pro-
blem of heavy metal and oil migration dur-
ing periods of precipitation was a negative
factor. The search now seemed to narrow to
the alternative of land farming as a means
to safely contain and degrade the oil mix-
tures from the lagoon.
The paper will now discuss the factors
surrounding the selection of a suitable
site, the design criteria for the site, the
disposal operation, the scientific monitor-
ing at the site, and future plans for the
site.
SITE SELECTION
When it appeared that land farming was
going to be the disposal method, prospec-
tive sites had to be selected and evalu-
ated. The sites would have to be in the
general vicinity of the lagoon so that
transportation costs could be kept to a
196
-------
minimum, the topography would have to per-
mit adequate drainage control, soil char-
acteristics would have to be suitable for
good drainage and microbial activity, and,
perhaps most important, the owners of the
site had to give their permission and
local officials (including neighbors) had
to be willing to allow the project to take
place.
From the technical and economic point
of view three possible sites were evalu-
ated. One site offered by the Union
Pacific Railroad was flat and alkaline but
was only 10 feet higher than the Great Salt
Lake which meant strong ground water influ-
ence. It was also an attractive duck hunt-
ing area. Trading one water-fowl problem
for another potential one would not have
been wise. The State of Utah offered a
site, but it was even lower in elevation
than the railroad offer and was saline; so
that site was deemed unsuitable.
The third site was under the control
of Hill Air Force Base, Ogden, Utah, and
was located 1-1/2 miles west of the oil
lagoon. There were areas of satisfactory
soil depth and gentle to 5% slopes. Drain-
age from the area was directed toward a
quarry where runoff could be controlled
and monitored. Soil properties had been
grossly characterized in surveys published
by the Department of Agriculture Soil Con-
servation Service. The soil was non-agri-
cultural and soil texture appeared excel-
lent from the standpoint of adequate aera-
tion and structure. The elevation ranged
30 to 120 feet above the level of the
Great Salt Lake. This site had no special
use at that time and was concluded to be
very desirable. The next step was to ob-
tain the necessary approvals and clear-
ances .
One of the primary tools available to
a Federal On-Scene Coordinator for manag-
ing an oil or hazardous chemical spill
incident is the National Oil and Hazardous
Substances Pollution Contingency Plan (1).
This plan establishes a framework for
regional contingency plans and a Regional
Response Team (RRT) which is made up of
representatives of Federal and State agen-
cies that have a key role or interest in
the spill incident. This RRT was effec-
tively used throughout all phases of the
Odgen Bay lagoon project and it was very
helpful in obtaining necessary approvals
for the land farm. The State of Utah's
Division of Health worked directly with EPA
on investigating sites which streamlined
their approval of the site. The Depart-
ment of Defense is one of the primary
agencies under the National Contingency
Plan and this facilitated good communica-
tions with local Air Force officials. The
pollution problems of the lagoon received
extensive local press coverage, especially
the distressed ducks and other waterfowl,
and many local officials and agencies were
anxious to be part of the solution. EPA
assured the Air Force that after two years
no significant land use restrictions
were anticipated at the site, other than
the possible prohibition of cattle grazing.
The Air Force and EPA then entered into an
agreement to use the site.
SITE DESIGN AND PREPARATION
Site Design Considerations
To develop an adequate design for the
project and to assist in disposal operations
EPA contracted with Dr. John S. Skujins,
Associate Professor of Soil Biochemistry
and Microbiology at Utah State University.
Representatives from EPA research labora-
tories, EPA regional and headquarters spill
control staffs, the State of Utah, and
local county officials also contributed to
this phase. It was assumed that the soil
would have to be enriched to provide ade-
quate nutrients for good microbial degra-
dation and the alkaline level would have
to be increased to neutralize the acidic
oil emulsion. Most soils in Utah are alka-
line in nature and would have simplified
the neutralization phase, but the Little
Mountain site was a Utah rarity, acid soil.
The primary reference for determining the
feasibility of land farming and establish-
ing initial design values was an EPA funded
project with Shell Oil Company in Deer Park,
Texas, on the disposal of oily refinery
waste by soil cultivation (2). One of the
primary objectives of the Shell project
was to reapply waste to an oiled plot as
soon as the degradation process had pro-
gressed sufficiently to permit the added
waste load. They also benefited from the
long growing season in the Houston area
and the plentiful rainfall. The Ogden Bay
project had design constraints of maximum
loading on a one-time application in an
area with less than 12 inches annual rain-
197
-------
fall; a cold, wet winter season followed
by a dry, hot summer season; and the
requirement to return the site to as many
original uses as possible.
The use permit for the site covered
approximately 200 acres on the south slope
of Little Mountain, of which only 40 acres
were found suitable for oil application
because of slope limitations, soil depth
requirements, rock outcroppings, and pre-
existing roads (Figure 1). Plots were
laid out and staked by Dr. Skujins and
then individually surveyed and mapped
(Figure 2). Base line soil samples were
taken and comparative analyses made by
Ford Laboratories, Salt Lake City, and by
the Ecology Center, Utah State University.
On the basis of the background analy-
ses and the projected oil application rate
required to dispose of the lagoon contents,
the quantities of lime, phosphorus, and
nitrogen to be added were calculated
(Table 1). The governing design assump-
tion was the application rate for the oil
emulsion phase. Using previous studies and
limited field and laboratory tests, a rate
of 10,800 gallons of oil/acre for a six
inch soil tilling depth was selected. This
rate was for oil alone and did not include
the water phase of the emulsion. In order
to keep an accurate record of total oil
applied to a plot, the water content of
the emulsion-water mixture spread on the
plots would have to be determined at fre-
quent intervals.
The application rates and procedures
recommended by Dr. Skujins were guides set
up with the realization that limitations
of equipment, time and money could result
in considerable modification of these
guidelines. Varying combinations of oil
and nutrient application rates between the
plots were chosen to provide information
for later phases of this project as well
as guidance for other land farming pro-
jects.
Site Preparation
Soil depth within the designated farm
plots ranged from 6 to 20 inches, with
several rock outcroppings occurring ran-
domly throughout the area. The entire
farm was ripped using a D-8 Caterpillar
dozer and a Caterpillar C-12 road grader
with a scarifier. Quantities of medium
to large size rocks on the surface
unearthed during this operation were
removed by hand labor. After ripping and
rock picking had been completed, the en-
tire area was cultivated to a depth of
approximately five inches by disc or barber-
shank harrow action. Both disc and harrow
were suspended by a three-point hitch and
worked effectively in the shallow tilling
operations required of them. However, the
barber-shank harrow proved better during
rock encounters due to its ability to pass
the rock between the teeth where the disc
would have to step over.
Plans then called for complete appli-
cation of lime and soil nutrients to the
farm before depositing lagoon liquids.
Lime nutrients were applied to plots A
through N (see Figure 2) using a standard
agricultural spreader. The plots were
cultivated again after the application of
lime and nutrients to provide good mixing
prior to the application of the oil emul-
sion. No additives were applied directly
to plots 0, P, Q, and R.
In order to prevent runoff of the oil
after application, the road grader was
used to establish 12 inch high berms
around the perimeter of the plots. Straw
bales were also considered for this func-
tion, but a shortage of straw in the area
discouraged this alternative. Using the
grader turned out to be much quicker and
cheaper.
SITE OPERATION
Spreading and Distribution
Two tank trucks normally used for dust
control in highway construction were used
for transporting and spreading the emulsion
at the land farm. Emulsion liquids were
top loaded into the transport tankers
using a Crisifulli centrifugal pump and a
field erected loading arm. Liquids were
discharged from the tankers onto the pre-
pared plots through a 12-inch rear, gravity
feed, exit port onto a horizontal splash
pan suspended 10 inches below the port.
The emulsion liquids were spread as uni-
formly as possible on the designated plots.
The application rate was gauged by compar-
ing the tanker volume to the area covered
at a given truck speed. One of the trucks
was a converted military 6X6 and was able
to operate over a wide speed range in the
plowed field. The other truck was a con-
198
-------
•8
e
O.
O
rt
01
-------
H-
TO
KJ
O
o
rt
I— '
ft>
s
Location Map
Scale I" = I mile
SLUDGE DISPOSAL SITE
SOUTH TIP OF LITTLE MOUNTAIN
-------
TABLE 1. SUGGESTED APPLICATION RATES
Plot
Designation
A
B
C
D
E
F
G
H
I
J
K
L
M
N
0
1)
2)
3)
4)
r-t
(D
(1)
O
i-t
ID
01
6.9
10.97
8.04
.73
0.96
0.87
0.91
1.08
.96
1.2
1.02
0.94
0.84
0.84
app. 17
Material
emulsion
emulsion
emulsion
emulsion
emulsion
emulsion
emulsion
sludge
sludge
sludge
sludge
emulsion
emulsion
emulsion
sludge
Amount of
Material per
Plot
75,700 gal
119,000 gal
86,600 gal
7,884 gal
10,368 gal
18,792 gal
19,656 gal
160 cu. yd
160 cu. yd
190 cu. yd
160 cu. yd
20,302 gal
18,144 gal
18,144 gal
1-1
n>
o
I-. fl,
"I
kg
1200
1900
1400
140
140
250
250
2200
2200
2200
2200
350
300
300
1000 metric tons 17,100
o
pa
rt
H-
O
20
50
50
50
10
20
50
20
50
50
10
20
50
100
20
:1
:1
:1
:1
:1
:1
:1
:1
:1
:1
:1
:1
:1
:1
:1 30
Theoretical
N
kg
5300
3310
2420
220
1455
1320
550
3890
1400
1730
7340
1470
508
254
,000
cj
I-t
0)
Ln
kg
12,
7,
5,
2,
3,
1,
8,
3,
3,
16,
3,
1,
67,
600
370
360
540
700
600
340
000
200
200
000
240
200
600
000
Includes approximately 125 kg Ca(OH)2 per acre 6" to stabilize soil pH
Should be applied as commercially available potassium phosphate. Theoretical value
obtain approximate commercial weight of weight of fertilizer (0-10-0) .
1 cc pure
7.5% pure
oil per 30 cc
oil in soil
soil
Theoretical
P 2)
kg
570
330
240
24
120
160
60
360
144
144
720
145
54
27
3,000
should
13
ya H-
fa o
rt fa
(D rt
H-
O
3
10,800 gal/6" /acre
10,800 gal/6"/acre
10,800 gal/6"/acre
10,800 gal/6"/acre
10,800 gal/ 6" /acre
21,600 gal/6"/acre
21,600 gal/6"/acre
60 metric tons/6"/acre
60 metric tons/6" /acre
60 metric tons/6"/acre
60 metric tons/6"/acre
10,800 gal/6"/acre
10,800 gal/6"/acre
10,800 gal/6"/acre
60 metric tons/6"/acre
be multiplied by 10 to
-------
verted civilian highway vehicle and did
not have a versatile speed range and occa-
sionally had trouble negotiating the ter-
rain. The field engineer exercised direct
control of all truck movements to ensure,
as nearly as possible, conformity with Dr.
Skujins recommended application rates. The
water content of the water-emulsion mixture
had to be expeditiously determined in order
for the field engineer to be reasonably
certain of the amount of oil to be added
to the plot. The normal test method would
be a time consuming Soxhlet extraction but
satisfactory results were obtained using
a gravimetric procedure based on the prin-
ciple of weight loss after drying. This
procedure showed the water content in the
emulsion mixture increased from approxi-
mately 50% in the lagoon to 60-65% after
pumping and transport.
Plans originally called for the emul-
sion to lay on the surface after spreading
to allow for short-term weathering in the
hot sun before final cultivation. However,
due to the mixing of the emulsion and aque-
ous phases by the truck loading pump, the
liquids discharged from the truck were less
viscous than expected and accumulated in
the tire depressions and tended to run. On
the first day of land spreading the threat
of rain required that one of the tractors
in use at the farm follow the tanker with
the disc or harrow, mixing dirt and emul-
sion to hold it in place. This immediate
cultivation was difficult because of the
slippery conditions, but no oil was ever
detected in runoff from the site.
As the mixed loads of emulsion and
aqueous layers were pumped from the lagoon
the proportion of the aqueous phase became
greater and separated. The aqueous layer
was decanted after load stratification
during transport, and, after the emulsion
started to flow, the air-actuated valve
was closed and the remainder of the emul-
sion was spread on designated plots.
The total volume of liquids removed
from the lagoon exceeded the original esti-
mate of 1,200,000 gallons, and, eventually,
1,675,000 gallons of liquid was removed
from the lagoon. This included approxi-
mately 721,327 gallons of emulsion and
905,510 gallons of aqueous phase which
was spread on 40.85 acres, and 47,825
gallons of aqueous phase which was spread
on farm roads for dust suppression (Table
2). After final liquid loads were placed
and nutrient spreading completed, desig-
nated plots were tilled to a depth of 5
inches with an agricultural rototiller or
cultivated with the barber-shank harrow.
Follow Up Site Operations
The liquid distribution and soil treat-
ment operations at the land farm were com-
pleted in May 1974. The work plan called
for remixing the soil with a rotary tiller
in the Fall of 1974 and the Spring and Fall
of 1975 to improve soil aeration. Addi-
tional applications of nitrogen in the form
of urea were also planned with reseeding,
if necessary, in the Fall of 1975.
In practice, the nutrient levels in
the plots stayed at a satisfactorily high
level in the Fall of 1974 and the soil was
very friable indicating good aeration pro-
perties. Refilling and nitrogen addition
was then delayed until Spring 1975. Re-
seeding was done in Fall of 1975 and addi-
tional tilling and nutrients were not
needed at that time.
SITE MONITORING
In order to thoroughly understand the
degradation process at the land farm and
assess the degree of recovery of the land
for reuse, EPA contracted with the Utah
State University Ecology Center and their
Departments of Biology and Soil Science and
Biometeorology. This section of the paper
is not a complete discussion of the study
methods and results from the Utah State
effort but is intended to provide the reader
with a general summary.
Samples were taken from the established
land farm plots and analyzed to determine
soil characteristics, nutrient levels,
heavy metals, pH, oil content, dehydrogen-
ase activity, soil respiration, microbial
activity, and microbial composition and
density. A summary of the findings of the
analyses of the samples and field observa-
tions follows.
The first sampling taken after appli-
cation of the oil emulsion and fertilizers
was June, 1974. At this time there was a
triple increase in dehydrogenase activity
202
-------
TABLE 2. LAND FARM APPLICATION RATES
o
OJ
Plot
A
B
C
D
E
F
G
H
I
J
K
L
M
N
S
rprft "k
0-R
Dust
Acres
6.90
10.97
8.04
0.73
0.96
0.87
0.91
1.08
0.96
1.20
1.02
0.94
0.84
0.84
4.20
0.99
4.4
Control
Emulsion
(gal/acre)
16,030
19,740
14,350
23,030
23,030
25,660
25,660
23,920
23,920
23,920
23,920
19,520
19,520
19,520
9,780
-
-
Aqueous
(gal/acre)
2,730
1,590
2,050
11,080
11,080
14,930
14,930
14,620
14,620
14,620
14,620
13,519
13,510
13,510
11,020
-
150,810*
47,825*
Lime
(Ibs/acre)
800
930
935
935
935
1,680
1,660
1,900
1,900
1,900
1,900
1,670
1,670
1,670
-
-
-
Phosphate
(20%)
(Ibs/acre)
250
250
250
250
500
750
250
500
500
750
750
750
500
250
-
-
—
Urea -'74
(45% N)
(Ibs/acre)
1,180
1,180
1,180
1,180
2,360
3,540
1,180
2,360
2,360
3,540
3,540
3,540
2,360
1,180
-
-
-
Urea -'75
(45% N)
(Ibs/acre)
735
735
735
960
1,540
2,425
850
1,430
1,465
2,700
2,345
2,095
1,675
840
-
-
-
Total 45.85 721,327 953,336 - All plots tilled to a depth of five (5) inches.
* 50 Ibs of lime for pH control was added to each truckload of aqueous solution as it was pumped from the lagoon.
** Contains approximately 630 cubic yards of oil-stained soil stripped from exposed surfaces of lagoon non-sludge
contaminated bottom and perimeter areas.
-------
compared to the activity before addition of
oil indicating that the oil decomposition
has begun. The samples taken in March,
1975, (the same season that control samples
were taken before oil application in 1974)
showed approximately 4 times as great an
activity. The April and May samples of
1975 showed a gradual decrease in activity,
as did the samples for the summer of 1974.
The November 1974 analyses again showed an
increase, probably due to the increase in
moisture during the fall.
The soil respiration values doubled
from March 1974 to June 1974. The amount
of C02 released decreased in the summer of
1974, but in the fall the respiration rate
more than tripled. High respiration levels
indicate that the oil is being degraded,
releasing excess COo• This sharp increase
in overall soil respiration during the wet
fall season may indicate more active micro-
bial degradation at that time. The res-
piration decreased slightly in the March
1975 samples, and continued to show an
overall decrease throughout the Spring. It
is also significant that the untreated sam-
pling site had a much lower rate of res-
piration than those plots treated with oil.
The chemical analysis of the soils
shows that the heavy metal content has not
changed over the year's time. The pH
values for most of the plots have not
changed appreciably over the year; they
still average 6.9 to 7.7.
The percent phosphorous has remained
about the same, but the percent nitrogen
in the soil decreased about two-thirds by
the end of 1974. The plots were reculti-
vated and two-thirds of the amount of N
applied in Spring 1974 was applied again
to the plots in Spring 1975. It is inter-
esting that the cation ex-change capacity of
the soil increased slightly. This is a
good indication that more organic matter is
being formed in the soil.
The total microbial numbers increased
sharply in June 1974. This was probably
a response to the water added to the plots
along with the oil and fertilizers. There
was a significant drop in total numbers
during the summer 1974. This was a rela-
tively hot, dry summer; therefore the micro-
bial numbers were probably responding to a
lack of moisture. The total aerobic num-
bers reached a level point in late fall of
1974, then apparently responded to the
moisture from winter with another signifi-
cant increase shown in March 1975. Other
experiments of this type have shown an in-
crease in microbial populations after con-
tamination by oil, possibly due to an
increase in nutrients and organic substrate
as the oil is broken down.
Total streptomycetes show the same
sharp increase after application of oil but
they do not show as drastic a drop in the
hot summer months. In the Spring of 1975
the streptomycete numbers had reached the
level that they were in June 1974.
The total fungi numbers do not respond
noticeably to the addition of oil. They
remain approximately the same throughout
the Summer, then begin to decrease, reach-
ing the low point in November 1974 and
throughout the winter to March 1975. The
April and May 1975 samples again show an
increase in numbers. This may be a result
of cultivating the soil again, providing
better aeration of the soil which the fungi
need. It appears that fungi are not sig-
nificant contributors to oil decomposition.
The anaerobic bacterial numbers do not
show any response to the addition of oil.
Their numbers change little until March
1975, when there is an increase. At this
point, the investigators are not certain
whether this increase is due to imperfect
anaerobic conditions or to increased anaer-
obic conditions in the very moist, undis-
turbed winter soil. There is a decrease in
the April samples, possibly because culti-
vation aerated the soil.
The hydrocarbon utilizers show the
greatest response to the addition of the
oil. Their numbers shot up to 10 per gram
of soil. This also dropped sharply in the
summer months as did the other groups.
March 1975 again showed an increase in
hydrocarbon utilizers.
The lipolytic organisms give the same
results as hydrocarbon utilizers. There
was a sharp increase after addition of oil,
then a sharp drop which leveled off until
November. March 1975 again showed a sharp
increase in numbers.
The major microbial species found
during the first vegetative season were
Corynebacterium, Bacillus, Arthrobacter,
Pseudomonas, Flavobacterium, Acinetobacter,
204
-------
Alcaligenes, Micrococcus, and a yeast;
Proteus, Serratia, and Staphylococcus, also
appeared. In the second vegetative season
so far we have generally observed a de-
crease in gram positive rods such as
Corynebacterium and an increase in gram
negative rods such as Acinetobacter. and
Alcaligenes occurred. Yeast species also
disappeared.
Oil on the fertilized plots had de-
graded approximately 80% by Fall 1975. On
a study plot that had not been fertilized
the oil had degraded only 55%. Since the
oils were originally lubricating oils they
were probably more complex chemically which
could retard degradation rates.
The cultivated plots have been in-
vaded by the wild sunflower at various
degrees. Plots E and F, and L to N have
limited invasion, whereas plot B has
luxurious growth. Others are intermediate.
The reasons for this variation has not
been evaluated as yet.
FUTURE PLANS
The information available at this
time on the degradation process is encour-
aging enough that further tilling or fer-
tilizer additions are not expected. Fu-
ture efforts will include continuing the
technical monitoring of the site by Utah
State University with some of the emphasis
shifting to heavy metals uptake by the
vegetation that grows on the plots.
BIBLIOGRAPHY
(1) Federal Register, Vol. 40, No. 28,
Part II, pp. 6282-6302, February 10,
1975
(2) Kincannon, B.C., Oily Waste Disposal
by Soil Cultivation Processes. EPA
R2-72-110. Office of Research and
Monitoring, U.S. Environmental
Protection Agency, Washington, D.C.,
1972
205
-------
BEHAVIOR OF HIGH PESTICIDE CONCENTRATIONS IN SOIL WATER SYSTEMS
J. M. Davidson, Li-Tse Ou and P. S. C. Rao
Soil Science Department, University of Florida
Gainesville, Florida 32611
ABSTRACT
Factors effecting pesticide mobility from hazardous waste disposal sites containing
high pesticide concentrations were examined. Major consideration was given to the in-
fluence of the shape of the adsorption isotherm on pesticide mobility. Equilibrium
adsorption of dimethylamine salt of 2,4-D [(2,4-Dichlorophenoxy) acetic acid] on Webster
silty clay loam was measured in the concentration range of 0-5000 pg/ml. The adsorption
isotherm was nonlinear in shape with the exponent in the Freundlich equation equal to
0.71. The adsorption sites for 2,4-D on the Webster soil were not saturated even in the
presence of 5000 yg/ml of 2,4-D (amine salt). The mobility of 2,4-D in the Webster soil
at various 2,4-D concentrations was simulated with a numerical solution to the solute
transport model. These simulations revealed that pesticide mobility increased as solution
concentration increased when N<1.0. However, an increase in solution concentration
resulted in a decreased mobility when N > 1.0. The pesticide solution concentration did
not influence the mobility when N=1.0. Serious errors may be introduced by assuming a
linear adsorption isotherm (N=l) when predicting pesticide transport under waste disposal
sites where high pesticide concentrations exist. A procedure for estimating the arrival
time of a selected pesticide concentration at various soil depths below a disposal site is
presented and discussed.
Organic pesticides currently play an
important role in food and fiber production
in the United States. These materials have
increased the efficiency of agricultural
production as well as improved man's living
conditions. In general, application con-
centrations for most agricultural, indus-
trial, and domestic systems are low and do
not pose a direct problem unless accumu-
lated in the soil or biological systems.
However, because of the volume of pesti-
cides being produced and used, the problems
associated with disposal of surplus and/or
waste pesticide materials and empty or
partially empty pesticide containers has
become acute.
The soil as a sink for the disposal of
pesticides has come under attack by en-
vironmentalists (1). Presently many un-
used pesticides and empty containers are
buried in the soil (45 - 60 cm below the
surface in sandy soils). This procedure
does not guarantee that the chemical pesti-
cide will remain at the disposal site.
Therefore, the disposal site and the area
around it may become contaminated and
hazardous to human and animal health as
well as plant and other biological systems.
Physical, chemical, and biological
processes that influence the fate and
behavior of specific pesticides present in
the soil at low concentrations (0 - 10 yg/
ml) have been studied extensively. How-
ever, the direct application of this in-
formation to soil-pesticide systems con-
taining chemical concentrations several
orders of magnitude higher have not been
considered in detail. For example, the
biological activity of previously viable
soil micro-organisms may be reduced or
stopped in the presence of a pesticide at
waste or container concentrations. Also,
pesticide movement through the soil and
into the groundwater may be increased sig-
206
-------
nificantly owing to adsorption-desorption
characteristics of a pesticide at high con-
centrations.
The application of existing pesticide-
soil information to describe the mobility
of pesticides from disposal sites contain-
ing high pesticide concentrations will be
discussed in this manuscript. Adsorption-
desorption characteristics for a pesticide
and soil will be given major consideration.
Also, a conceptual process-oriented ap-
proach to modeling pesticide behavior in
soils will be presented.
THEORY
The mobility of a pesticide molecule
in a soil-water system is directly in-
fluenced and controlled by the adsorption-
desorption characteristics for the pesti-
cide and soil. Several reviews describe
in considerable detail mechanisms for pes-
ticide adsorption by soils (2,3,4,5). In
order to quantitatively describe the in-
fluence of adsorption on mobility, the
adsorption-desorption characteristics must
be described analytically. Numerous equa-
tions have been used to describe adsorption
isotherms for pesticides (3,4). The
Freundlich, Langmuir, and first-order
kinetic equations are the most commonly
used in the 0-10 yg/ml pesticide concen-
tration range.
The Freundlich equation is purely
empirical and may be stated as
KG
,N
[1]
where S is the amount of pesticide adsorbed
per gram of soil (yg/g), C is the pesticide
concentration in solution (yg/ml), and K
and N are coefficients that vary with the
chemical and soil. Equation [1] is valid
only when equilibrium conditions exist
between the adsorbed and solution phases.
The empirical nature of the Freundlich
equation is illustrated by the fact that a
maximum adsorbed concentration is not
reached as the solution concentration, C,
increases without limit. However, the
Freundlich equation has been successful
for intermediate pesticide concentrations
(3) where N was approximately unity.
A first-order kinetic adsorption equa-
tion has been used to describe adsorption
in systems where soil-water flow exists
(6). The kinetic adsorption equation may
be written as:
_3S
3t
^C - S
[2]
where t is time (hr), k^ and kD are forward
and backward rate coefficients (hr~l), 6 is
soil-water content fraction (cm^/cm^), p is
soil bulk density (g/cm^), and the other
terms are the same as those described pre-
viously. Note that when 3S/3t=0 (equili-
brium) equation [2] reduces to equation [1]
for N=1.0 and K=k^6/kDp. This approach is
limited to the case where the equilibrium
adsorption isotherm is linear and therefore
may not be valid for systems with high
pesticide concentrations.
The Langmuir equation is more concep-
tual in its description of adsorption and
may be written as,
S =
Smax b C
1 + bC
[3]
where b is analogous to k^/kp (equation 2)
and Smax is the maximum concentration that
can be adsorbed by the soil. In general,
the Langmuir equation has not been as
successful as the Freundlich equation in
describing pesticide adsorption in soil-
water systems. The failure of the Langmuir
equation is not surprising in that it
assumes the energy for adsorption is con-
stant and independent of surface coverage.
Soils, because of their characteristic
mixture of colloidal materials, do not have
the same energy of adsorption over the
entire surface area.
The movement of pesticides and other
solutes through soils, under steady state
soil-water flow conditions, have been
described by the following partial differ-
ential equation (6,7,8,9):
_3C
3t
= D
3x
[4]
where D is the dispersion coefficient
hr), V is the average pore-water velocity
(cm/hr), (Darcy flux divided by soil-water
content fraction), and the other terms are
as described previously. The dispersion
coefficient is a function of the average
pore-water velocity (10). The first two
terms on the right hand side of equation
[4] describe the transport of the solute
207
-------
and the third term the adsorption-desorp-
tion of the solute. If the adsorption pro-
cess is linear (equation 1 with N=1.0)
equation [4] reduces to
3C
32C
3C
where,
[5]
[6]
and R is the retardation term (11). If the
adsorption isotherm is nonlinear (N<1.0 or
to >1.0), the retardation term is not a con-
stant, but is dependent on the solution
concentration as follows:
R = 1 +
[7]
However, a weighted-mean value (R) for the
retardation term may be estimated (12),
R = 1 +
N-l
[8]
where, C0 is the maximum or incoming pesti-
cide concentration (yg/ml). The influence
of nonlinearity of the adsorption isotherm
on pesticide mobility will be discussed
later.
MATERIALS AND METHODS
The soil used in this study was ob-
tained from the top 15 cm of a profile
classified as Webster silty clay loam
(Typlc Haplaquoll). The soil profile is
located in Boone County Iowa. The pH,
organic matter content, and cation exchange
capacity of the soil were 7.3, 3.87%, and
54.7 me/lOOg, respectively. The soil had
19%, 43%, and 39% sand, silt, and clay,
respectively. The soil was air-dried and
passed through a 2.0 mm sieve prior to
storage and use.
Equilibrium adsorption of dimethyla-
mine salt of 2,4-D [(2,4-dichlorophenoxy)
acetic acid] on the Webster soil was
measured using a batch experiment proce-
dure. The 2,4-D solutions were prepared
in 0.01 N CaCl2 and spiked with 3.6 yCi/1
of l^C ring-labeled 2,4-D. Solution con-
centrations of 10, 50, 100, 500, 1000, and
5000 yg/ml were used for the adsorption
study. A 5 g sample of the Webster soil
and 10 ml of 2,4-D solution were equili-
brated by shaking for 48 hrs. Following
the equilibration, the samples were cenr,
trifuged at 800 x G for 30 min and the ^C
activity in the clear supernatent was
determined by liquid scintillation. Tri-
plicate samples were used for each con-
centration. The difference between ini-
tial herbicide concentration and the con-
centration in the supernatent was taken to
be the amount of 2,4-D adsorbed by the
soi . A mixture of antibiotics were added
to all 2,4-D solutions to prevent the
possibility of microbial degradation of
2,4-D during the 48 hr shaking period. The
adsorption experiment was conducted at a
constant temperature of 25 + 0.5°C.
A numerical solution to equation [4]
was used to simulate the mobility of 2,4-D
at various concentrations in a Webster
soil. The adsorption isotherm for 2,4-D
and Webster soil was used to describe the
adsorption-desorption process in equation
W.
RESULTS AND DISCUSSION
The adsorption isotherm for 2,4-D
(dimethylamine salt) and Webster soil is
presented in Figure 1. The data described
by the Freundlich equation (equation 1)
with K=4.34 and N=0.71. The fact that
equation [l] describes the adsorption of
2,4-D over the concentration range studied
(0-5,000 yg/ml) indicates that the adsorp-
tion sites were never saturated. This is
not true for all 2,4-D adsorbent systems
(13). The nonlinear relationship between
the adsorbed and solution 2,4-D concentra-
tion phases has a direct influence on the
mobility of 2,4-D in the Webster soil.
Many studies have assumed and/or measured
a linear relationship at low pesticide
concentrations (14,15,16).
The significance of a nonlinear ad-
sorption isotherm with regards to pesticide
mobility was examined by simulating 2,4-D
movement in the Webster soil with a numeri-
cal solution (9,17) of equation [4]. For
the simulations, the values of p, 6, V,
and D were assumed to be 1.4 g/cm^, 0.3
cm3/cm3, 3.0 cm/hr, and 1.0 cm2/hr, respec-
tively. The values for K and N were taken
from the experimentally measured isotherm
unless stated otherwise (Figure 1). For
the case considered in Figure 1, a pulse of
2,4-D with C0=5000 yg/ml was introduced at
the soil surface (x=0) for a period of 22
208
-------
hrs, followed by an input of water with
Co=0 for an additional 48 hr period (total
of 70 hrs).
4 Amine Salt 2.4-D on Iowa Webster Soil
= 4.34(C071)
10°
101 1O2 1O3
SOLUTION CONCENTRATION
(mg /ml)
Figure 1. Adsorption isotherm for 2,4-D
(amine salt) and Webster Silty clay
loam.
Two simulated cases, N=0.7 and N=1.0, are
presented in Figure 2. These illustrate
that 2,4-D is less mobile at high concen-
tration when N=1.0 than when N=0.7. The
front of a nonreactive solute (eg. chlo-
ride) would be located at 210 cm for the
above conditions (70 hr times the 3.0 cm/hr
average pore-water velocity). The apparent
difference in areas under the curves shown
in Figure 2 is because more of the 2,4-D
is in the adsorbed phase when N=1.0. The
nonlinear isotherm N<0.1 also leads to an
asymmetrical concentration distribution
profile (Figure 2). The information pre-
sented in Figure 2 clearly points out the
seriousness of assuming a linear isotherm
to predice pesticide mobility under waste
disposal sites where the pesticide concen-
trations may be high.
The mobility of a pesticide is also
influenced by the magnitude of the solu-
tion concentration when the adsorption
isotherm is nonlinear. Figure 3 presents
the simulated 2,4-D concentration distri-
butions in the Webster soil profile for
two pesticide concentrations (Co=10 and
5000yg/ml.. These curves.were simulated
using the same procedure as described
above for Figure 2. The pesticide is much
more mobile at high concentrations than at
low concentrations.
RELATIVE CONC, C/C0
O 0.2 0.4 0.6 0.8
E
u
Q.
LJ
Q
0
20
40
60
1.0
C0=50OOjjg/ml
v =3 cm/hr
t =7O hrs.
O
00 80
100L
Figure 2. Simulated relative 2,4-D con-
centration distributions in the soil
solution phase of Webster soil.
0
RELATIVE CONC., C/C0
0 Q2 0.4 0.6 0.8
Cp=5000>jg/ml
100U
Figure 3. Simulated relative 2,4-D con-
centration distributions in the soil
solution phase of Webster soil.
Both curves are asymmetrical in shape due
to the nonlinearity (N=0.7) of the adsorp-
tion isotherm.
The dependence of pesticide mobility
on the shape of the adsorption isotherm
and solution concentration is summarized
in Table 1. The retardation terms pre-
209
-------
sented in Table 1 were calculated by using
equation [8], with p=1.4 g/cm3, and 9=0.3
cm3/cm3. A larger value for the retardation
term represents a decreased mobility of the
pesticide. The position of the pesticide
front may be estimated by dividing the depth
of water penetration (average pore-water
velocity times input period) by the retarda-
tion term. It is apparent from the data
presented in Table 1 that the pesticide
mobility increases as CQ increases when N<
1.0. However, an increase in solution con-
centration results in decreased pesticide
mobility when N > 1.0. The retardation
terms are equal for all concentrations when
N=1.0, and also equal for N values when
C0=1.0 Vig/ml (Table 1). Thus, the error
introduced by assuming linear adsorption
isotherms may not be serious at low concen-
trations (< 10 yg/ml) but becomes significant
at high pesticide concentrations.
TABLE 1. RETARDATION TERMS FOR VARIOUS
PESTICIDE CONCENTRATIONS USING EQUATION
[8] AND BULK DENSITY AND SOIL WATER
CONTENT OF 1.4 g/cm3 AND 0.3 cm3/cm3.
RESPECTIVELY.
N
0.7
1.0
1.3
1
21.2
21.2
21.2
10
11.1
21.2
41.4
C0 (pg/ml)
100 1000
6.1
21.2
81.6
3.5
21.2
161.8
10,000
1.9
21.2
322.0
The pesticide transport model repre-
sented by equation [4] can also be utilized
to predict the time required for a specific
relative soil solution concentration (C/CO)
to be reached at any depth in the soil pro-
file below a waste disposal site. The solu-
tion concentration entering the soil at the
bottom of the waste disposal site is assumed
to be constant and equal to Co. Predicted
relative concentrations (C/CQ) at selected
depths for various reduced time (T/R) are
shown in Figure 4. The C/C0 values are
plotted on probability scale, while the
values of T/R are plotted on a log scale.
The reduced time scale can be converted to
real time by multiplying the T/R values by
the average retardation term (R) for the
soil-pesticide system in question (equation
8). The lines in Figure 4 were obtained
under the assumption that a given amount of
water passes through the disposal site (V
is the average pore-velocity, m/yr). Graphs
similar to Figure 4, but for different
groundwater recharge rates can be generated
with an analytical solution (11) to equation
[4], Graphs similar to Figure 4 may be of
value in establishing site selection cri-
teria.
0.99
o
o
\
O 0.90
O
Z 0.50
O
o
LJ 0.10
UJ
cr
o.oi
= 0.438 m/yr
= 0.0
d_
i 10 • wo
REDUCED TIME, T/R (yr)
Figure 4. Simulated concentrations at
various depths versus reduced time.
The average pore-water velocity, V,
times the average volumetric soil-
water content fraction gives annual
recharge rate.
Because most soil profiles are stra-
tified in the vertical direction, consider-
able computer time is required to solve
equation [4] for a soil profile with
different soil-water and physical charac-
teristics as well as solute adsorption
properties in each layer. Numerical simu-
lations of various multilayered soil pro-
files have shown, however, that the soil
stratification sequence does not alter the
shape or position of an effluent concentra-
tion distribution (17). Experimental re-
sults from the misicible displacement of
36C1 and 14c-labeled 2,4-D through a two-
layered soil column supported the simulated
210
-------
results (17). Based on these results, it
was concluded that effluent concentration
distributions from multilayered soil pro-
files could be predicted by treating the
soil as homogeneous or unstratified. The
mathematical solution uses a weighted-mean
retardation term based on the retardation
terms for each layer in the profile. The
procedure, however, can only be used for
equilibrium linear and nonlinear adsorption
processes.
SUMMARY
The shape of the adsorption isotherm
plays a significant role in determining the
mobility of adsorbed pesticides. This is
especially important when considering high
pesticide concentrations such as those found
under a waste disposal site. Mobility
studies conducted at low pesticide concen-
trations may not be of value for predicting
the location of pesticides from a point
source of high concentration. Pesticide
mobility studies involving chemicals other
than 2,4-D and soils representing five major
soil orders in the United States are cur-
rently being conducted in our laboratory.
ACKNOWLEDGEMENTS
This research was supported in part by
the U.S. Environmental Protection Agency
(Grant No. R-803849-1) and in part by
special funds from the Center for Environ-
mental Programs of the Institute of Food
and Agricultural Sciences, University of
Florida. Florida Agr. Exp. Station Journal
Series No. 9017.
REFERENCES
1. Atkins, P. R. 1972. The Pesticide
Manufacturing Industry - Current Waste
Treatment and Disposal Practices.
Water Pollution Control Res. Series
12020 FYE 61/72. pp. 185.
2. Adams, Russell S., Jr. 1973. Factors
Influencing Soil Adsorption and Bio-
activity of Pesticides. Residue
Review 47:1-54.
3. Bailey, G. W., and J. L. White. 1970.
Factors Influencing the Adsorption,
Desorption, and Movement of Pesticides
in Soil. Residue Review 32:29-92.
10.
11.
12.
Green, R. E. 1974. Pesticide-Clay-Water
Interactions. J_n W. D. Guenzi (ed.)
Pesticide in Soil and Water. Amer. Soc.
Agron., Madison, Wise.
Hamaker, J. W., and J. M. Thompson.
1972. Physicochemical Relationships of
Organic Chemicals in Soils - Adsorption
In; Organic Chemicals in the Soil
Environment (Goring, C. A., and J. W.
Hamaker, ed.) Marcel Dekker, Inc., New
York, p. 49.
van Genuchten, M. Th., J. M. Davidson,
and P. J. Wierenga. 1974. An Evaluation
of Kinetic and Equilibrium Equations
for the Prediction of Pesticide Move-
ment Through Porous Media. Soil Sci.
Soc. Amer. Proc. 38:29-35.
Lindstrom, F. T., L. Boersma, and D.
Stockard. 1971. A Theory on the Mass
Transport of Previously Distributed
Chemicals in A Water Saturated Sorbing
Porous Medium: Isothermal Cases. Soil
Sci. 112:291-300.
Hornsby, A. G., and J. M. Davidson.
1973. Solution and Adsorbed Fluometuron
Concentration Distribution in a Water-
saturated Soil: Experimental and Pre-
dicted Evaluation. Soil Sci. Soc.
Amer. Proc. 37: 823-838.
Wood, A. L., and J. M. Davidson. 1975.
Measured and Calculated Fluometuron
and Water Content Distributions During
Infiltration. Soil Sci. Soc. Amer.
Proc. 39:820-825.
Kirda, C., D. R. Nielsen, and J. W.
Biggar. 1973. Simultaneous Transport of
Chloride and Water During Infiltration.
Soil Sci. Soc. Amer. Proc. 37:339-345.
Lindstrom, F. T., R. Haque, V. H.
Freed, and L. Boersma. 1967. Theory on
Movement of Some Herbicides in Soils.
Linear Diffusion and Convection of
Chemicals in Soils. Environ. Sci.
Technol. 2:561-565.
Rao, P. S. C. 1974. Pore-Geometry
Effects on Solute Dispersion in Aggre-
gated Soils and Evaluation of a Predic-
tive Model. Ph.D. Dissertation. Uni-
versity of Hawaii. Diss. Abstr.
Internl. 36(2):527-B.
211
-------
13. Weber, W. J., Jr. and P. J. Usinowicz.
1973. Adsorption from Aqueous Solu-
tion. Tech. Publication, Research
Project 17020 EPF, U.S. Environmental
Protection Agency, Cincinnati, Ohio.
14. Harris, C. I. 1966. Movement of Her-
bicides in Soils. Weeds 15:214-218.
15. Huggenberger, F., J. Letey, and W. J.
Farmer. 1972. Observed and Calculated
Distribution of Lindane in Soil
Columns as Influenced by Water Move-
ment. Soil Sci. Soc. Amer. Proc. 36:
544-548.
16. Kay, B. D., and D. E. Elrick. 1967.
Adsorption and Movement of Lindane in
Soils. Soil Sci. 104:314-322.
17. Selim, H. M., J. M. Davidson, P. S. C.
Rao. 1976. Transport of Reactive
Solutes through Multilayered Soils.
Soil Sci. Soc. Amer. J. (submitted).
212
-------
THE MOBILITY OF THREE CYANIDE FORMS IN SOILS
B.A. Alesii and W.H. Fuller
Department of Soils, Water and Engineering
The University of Arizona
Tucson, Arizona 85721
ABSTRACT
Three solutions of cyanide, KCN in de-ionized water (simple form), ICiFeCClOg in de-
ionized water (complex form) and KCN in natural landfill leachate (mixed form) were each
leached through five soils (Ava, Kalkaska, Mohaveca> Molokai, and Nicholson) of varying
physical and chemical properties to evaluate which soil characteristics govern the move-
ment of the various cyanide forms in soils. The effluent from each column was collected
and analyzed for total cyanide each day. In general, KCN and ^FetCN)^ in water were
both found to be very mobile in soils, while KCN in landfill leachate was found to be
less mobile. Soil properties such as low pH, presence of free-iron oxide and kaolin,
chlorite and gibbsite-type clay (high positive charges) tended to increase attenuation
of cyanide in the three forms. High pH, presence of free CaC03 (high negative charges),
low clay content and montmorillonite clay tended to increase the mobility of the three
cyanide forms.
INTRODUCTION
Man's new sensitivity toward nature
has caused him to seek new answers about
the environment which surrounds him. Pre-
sently a busy area of research is the study
of toxic compounds in soils. Cyanide is
one of the compounds in question.
Cyanide is introduced into the soil by
natural means and through the activities of
man. It is produced naturally by several
fungi (Bach, 1956), at least one bacterium
(Michael and Corpe, 1965), and many mem-
bers of the higher plant community (Robin-
son, 1962). The amount produced by these
organisms is rather insignificant when
compared to the quantity which is discarded
each day as a waste product of some modern
industries. Cyanide has been used exten-
sively since the 1800's for extracting
precious metals and for stripping undesir-
able foreign substances from metal surface
before plating. Cyanide is introduced into
the waste system by drag-out losses, leak-
age and accidental tank spills. Rudolph
(1953) estimated cyanide concentration of
the CN® in the waste stream of cyanide
plants varied from 100 mg/1 to 50,000 mg/1,
depending on the efficiency of the plant
and the process involved.
The highly toxic nature of the cyanide
ion has been well documented. Ludzach
(1951) and Schant (1939) found that it has
an inhibitory effect on fish life at a con-
centration as low as 0.3 ppm. The U.S.
Public Health Service (1961) suggested
0.01 mg of HCN/1 to be the limiting con-
centration of cyanide in drinking water.
These figures indicate the harmful effect
that uncontrolled dumping of cyanide waste
could have on aquatic life and human health.
Fortunately, cyanide waste is treated in
most plants. Methods range from chemical
treatment (alkaline chlorination, acidifi-
cation, ponding, complexation, ozonation
and electrolytic oxidation) to biological
treatment using activated sludge (Murphy
213
-------
and Nesbitt, 1964). Although some of
these processes (alkaline chlorination and
activated sludge) are quite effective,
none of them completely remove the
cyanide.
Due to the highly toxic nature of
cyanide, it is important to gather infor-
mation on its behavior in soils. The
object of this investigation was to
measure cyanide mobility in soils and to
determine which soil properties govern
the mobility and/or attenuation of
cyanide in soil.
MATERIALS AND METHODS
Three solutions of cyanide (Table 1),
KCN in de-ionized water (simple form),
K3Fe(CN)g in de-ionized water (complex
form) and KCN in natural landfill leach-
ate (mixed form) were each leached through
five soils (Ava silty clay loam, Kalkaska
sand, Mohaveca clay loam, Molokai clay
and Nicholson silty clay). Table 2 shows
some of the soil characteristics.
Taras (1971) defines the simple and
complex form of cyanide as follows:
A(CN)X
where A = an alkali (Na, K, NH^ or
other metallic cations
x = the valence of A and the
number of CN groups
CN is present as CN® in solution
Complex form (Alkali-metallic cyanide)
AyM(CN)x
where A = the alkali present y times
M = the heavy metal (Fe3+, Fe +
and others)
e
x = the number of CN° groups which
is equal to the valence of A
taken y times plus that of
the heavy metal.
The anion radical in the complex
form appears as M(CN)X®.
TABLE 1. CHARACTERISTIC OF CYANIDE SOLUTION
Cyanide Solution
pH of Solution
Concentration of
Cyanide in Solution
Type of Ion
Present
ppm
KCN in de-ionized
water
10.0
97
CNC
K3Fe(CN)e in de-
ionized water
1.5
98
Fe(CN)
KCN in landfill
leachate
7.0
80
Unknown
214
-------
TABLE 2. CHARACTERISTICS OF SOILS
Soil
Ava
(Illinois)
Kalkaska
(Michigan)
Molokai
(Hawaii)
Nicholson
(Kentucky)
Mohave£a
(Arizona)
Order
Alfisol
Spodosol
Oxisol
Alfisol
Aridisol
PH
4.4
4.6
6.2
6.7
7.8
CEC
meq/
lOOg
19
10
14
37
12
EC
ymhos/
cm
207
75
1262
176
510
Surface
Area
m2/g
61.5
8.9
67.3
120.5
127.5
Free
Iron
Oxide
%
4
1.8
23
5.6
2.5
Bulk
Den-
sity
cm3/g
1.36
1.5
1.33
1.34
1.53
Sand
%
6
95
23
3
32
Silt
%
67
3
25
47
28
Clay
%
27
2
52
49
40
Texture
Class
Silty
Clay
Loam
Sand
Clay
Silty
Clay
Clay
Loam
Predominant
Clay
Mineral
Vermiculite
Kaolinite
Chlorite
Kaolinite
Kaolinite
Gibbsite
Vermiculite
Mica
Montmorillonite
-------
The mixed material contains both the
simple and complex forms. The formation
of blue precipitate occurred when KCN was
added to the leachate. Tests indicated
the precipitate to be Prussian blue
([Fe(CN)6]3Fe^). Other compounds of
cyanide are present, but their actual
identity is unknown.
The natural municipal solid waste
leachate was produced by packing represen-
tative solid waste in a 3800 1 commercial
septic tank, saturating it with water and
letting it digest for several months. Con-
centration levels of some constituents in
the leachate appear in Table 3.
TABLE 3. ANALYSIS OF THE NATURAL LEACH-
ATE FROM A MUNICIPAL WASTE-TYPE
LANDFILL USED IN THIS STUDY
PH
EC (ymhos/cm)
K (ppm)
Na (ppm)
Ca (ppm)
Mg (ppm)
Zn (ppm)
Si (ppm)
Cl (ppm)
Fe (ppm)
Mn (ppm)
6.7
2500
240
60
160
33
.3
14
200
90
1.3
Miller (1906) reported carbon dioxide
tended to degrade cyanide. Therefore,
the leachate was aerated and the de-
ionized water was boiled to drive off the
dissolved C02-
The soils used were collected from
the B and/or C horizons, dried in air
and passed through a 2 mm sieve. Each
soil was packed in a PVC column 5 cm in
diameter and 10 cm long to a specified
bulk density greater than natural condi-
tions to avoid column side effects and
insure uniform flow throughout.
The soils were saturated in an invert-
ed position to provide uniform wetting and
to exclude air. The cyanide solutions
were pumped through the soil using a
Pharmacia (Piscataway, NJ) Paristaltic
pump. The flow rate was regulated to
deliver approximately one pore volume of
effluent per day. The effluent was col-
lected in 125 ml plastic bottles contain-
ing 5 ml of 1 N NaOH. Sodium hydroxide
stabilizes any cyanide coming through the
column. The eluate was analyzed for total
cyanide each day by the Liebig distilla-
tion method (Taras, 1971). Distillation
of the sample is required to convert all
the cyanide forms in the sample to simple
cyanide (NaCN) which can be easily ana-
lyzed by the Liebig distillation method
using silver nitrate and Rhodanine indi-
cator (Taras, 1971).
RESULTS AND DISCUSSION
The relative mobility of the three
cyanide solutions is best illustrated in
Mohave,-, clay loam and Kalkaska sand
(Figures 1 and 2) . All data are plotted
as pore volume versus C/Cmax, where C/Cmax
is the ratio of effluent concentration to
influent concentration. KCN and K^Fe^N)^
in de-ionized water were both found to be
very mobile in soils, while KCN in landfill
leachate was the least mobile of the three
solutions .
The effect of soil type on the move-
ment of the three cyanide solutions is
illustrated in Figures 3, 4, and 5. Fig-
ure 3 shows the amount of KCN in de-ionized
water that was leached through four soils,
MohaveQa, Ava, Nicholson, and Molokai.
The figure indicates KCN leached most
rapidly in the soil having the highest
pH and free CaCO^ (Mohave^ clay loam) .
The negative charges on the clay surface
of Mohave^a tends to repel the CN®, causing
it to be leached out more rapidly than in
acid soils. The CN® was retained most by
soils having a high concentration of Mn
and hydrous oxides of Fe (Nicholson silty
clay and Molokai clay). Korte et al.
(1975) found similar results working with
the anion forms of As, Cr, Se, and V.
This conclusion is further supported by
data from Berg and Thomas (1959) . They
found
which is similar to CN® in its
216
-------
l.Or-
A-
KCN in water
KjFe (CN)6 in water
KCN in leachate
I
I
-A
10
12
Figure 1.
2468
PORE VOLUME
Relative mobility of KCN in de-ionized water, K3Fe(CN)s in
deionized water and KCN in leachate through Kalkaska sand.
14
217
-------
l.Oi-
:6—8
-A—A
K3Fe(CN)6 in water
KCN in water
KCN in leachate
I
I
I
02468 TO12
PORE VOLUME
Figure 2. Relative mobility of KCN in de-ionized water, K3Fe(CN)s in
de-ionized water and in leachate through Mohaveca clay loam.
T4
218
-------
l.Or
.8
.6
X
et
.2
// „/
' .s
s\ \
2 4
.xu *>
_• A
, n — L\
D-
I i
6 8
Molakai
1 1
10 12
1
14
PORE VOLUME
Figure 3. Relative mobility of KCN in de-ionized water through four diverse
soils.
219
-------
l.Or
A-A
D D D D
Mohaveca
O Nicholson
•D Kalkaska
•A Ava
,__A—A'
i
i
i
10
12
j
14
Figure 4. Relative mobility of
diverse soils.
PORE VOLUME
in de-ionized water through four
220
-------
1.0
.6
" -4
O
.2
-A Ava
-D Kalkaska
-O Nicholson
-X Molokai
i—A.—a n
6 8
PORE VOLUME
10
12
14
Figure 5. Relative mobility of KCN in leachate through four diverse soils
221
-------
adsorption behavior, attenuated in soils
having a high percentage of kaolin clay
and iron and aluminum oxides. Schofield
(1939) also reports that soils high in
these oxides have a high anion exchange
capacity. Kamprath (1956) found good
retention of SO,/,2" by an acidic soil high
in oxides and kaolin, whereas the 3-layer
minerals appeared to have poor retention
for SO^2". The acidic soil (Ava silty
clay loam) in this study proved on the
contrary, to be a poor attenuator of CN".
Texture seems to have little measurable
effect on the attenuation of KCN. Free
iron oxide and CaCO^ seem to have a
greater influence on the movement of KCN
in water than either soil pH or texture.
Figure 4 illustrates the movement
of K3Fe(CN)6 in de-ionized water through
four soils (Mohaveca clay loam, Ava silty
clay loam, Nicholson silty clay loam and
Kalkaska sandy loam). The ferricyanide
ion also migrated most rapidly through
soils having a high pH and in the presence
of free CaC03 (Mohave^a clay loam) for the
same reason as KCN in water. Ferricyanide
moved slowest in soils having a low pH
(Ava silty clay loam and Kalkaska sandy
loam). A low pH would indicate the clay
surface to have a high percentage of
positive exchange sites which would attract
the Fe(CN)63~ ion and retain it. Texture
seems to play a more important role in
this case. The high clay content soil
(Ava silty clay loam) retained more of the
Fe(CN)53~ than the sandier soil of similar
pH (Kalkaska sandy loam). Although iron-
oxide seemed to have some affinity for
Fe(CN)g3-5 its presence was not as effec-
tive as soil pH in governing the movement
of this form of cyanide.
Figure 5 portrays KCN in landfill
leachates migrating through four soils
(Ava silty clay loam, Kalkaska sandy loam,
Nicholson silty clay and Molokai clay).
This solution moved most rapidly through
soils with low pH (Ava silty clay loam
and Kalkaska sandy loam). Cyanide was
retained most by soils having a high
concentration of iron-oxide. Cyanide in
leachate seemed to behave similarly to
KCN in de-ionized water.
Of the three solutions, KCN in leach-
ate was found to be attenuated the best.
This can be partly explained by the pre-
cipitation of Prussian blue when KCN was
added to the leachate (Robine, Lenglen and
LeClere, 1906). This blue precipitate was
found permeating the top 4 cm of the soil
columns. The accumulation indicates that
Prussian blue may be quite immobile in
soils. The cyanide that came through the
soil probably was the CN0 that did not
react with the Fe in solution to form
Prussian blue.
The anaerobic state of the soil col-
umns inhibited any microbial degradation
of cyanide. Micro-organisms responsible
for degrading cyanide under anaerobic
conditions are very sensitive to high
cyanide concentration. Coburn (1949)
found 2 ppm in the wastestream to be the
limit for effective anaerobic degradation
of cyanide. This concentration is much
less than that passed through the soil
columns.
CONCLUSION
Cyanide as Fe(CN)63 and CN0 in water
were found to be very mobile in soils.
Cyanide as KCN in natural landfill leach-
ate was found to be less mobile. Soil
properties such as low pH, percent free-
iron oxide and kaolin, chlorite and
gibbsite type clay (high positive charges) ,
tended to increase attenuation of cyanide
in the three forms. High pH, presence of
free CaCOg (high negative charges), low
clay content and montmorillonite clay
tended to increase the mobility of the
cyanide forms. Cyanide could possibly
contaminate the groundwater if proper
treatments are not used.
ACKNOWLEDGMENT
This research was supported in part
by the U.S. Environmental Protection
Agency, National Solid and Hazardous Waste
Research Center, from Contract No.
803988-01; Arizona Agricultural Experiment
Station Paper No. 182.
222
-------
REFERENCES 11.
1. Advisory Committee on Revision of U.S.
P.H.S. August 1961. 1946 Drinking Water
Standards, Drinking Water Standard 1961.
Journal of American Water Works 12.
Association. 53(8):935.
2. Bach, E. 1956. "The Agaric Phaliota
aurea: Physiology and Ecology. Dansk 13.
Botau. Arkiv., 16, Hefte 3.
3. Berg, W.A. and G.W. Thomas. 1959.
Anion Elution Patterns from Soils and 14.
Soils Clays. Journal of Soil Science
Society of America Proceedings. 23:348.
4. Coburn, S.E. 1949. Limits of Toxic
Wastes in Sewage Treatment. Sewage 15.
Works Journal 21(3):522.
5. Kamprath, E.J., W.L. Nelson and J.W.
Fitts. 1956. The Effect of pH, Sulfate
and Phosphate Concentration on the 16.
Adsorption of Sulfate by Soils.
Journal of Soil Science Society of
American Proceedings. 20:463-466.
6. Korte, N.E., J. Skopp, W.H. Fuller,
E.E. Niebla and B.A. Alesii. 1975.
Trace Element Movement in Soils:
Influence of Soil Physical and
Chemical Properties. Soil Science
(In press).
7. Ludzack, F.J. , W. Allan Moore, H.L.
Krieger and C.C. Ruchhoft. 1951.
Effect of Cyanide on Biochemical Oxi-
dation in Sewage and Polluted Water.
Sewage and Ind. Waste 23(10):1298-1307.
8. Michael, R. and W.A. Copre. 1965.
Cyanide Formation by Chromabacterium
violaceum. Journal of Bacteriology.
89:106-112.
9. Miller, A.S. 1906. The Cyanide Process.
New York, John Wiley and Son Publishing
Co., p. 12-34.
10. Murphy, R.S. and J.B. Nesbitt. June
1964. Biological Treatment of Cyanide
Waste. Engineering Research Bulletin
B-88. p. 1-10.
Robine, R., M. Lenglen, and J.A.
LeClere. 1906. The Cyanide Industry
Theoretically and Practically Con-
sidered. New York, John Wiley and
Son Publishing Co., p. 1-84.
Robinson, T. 1962. The Organic Consti-
tuents of Higher Plants. Minneapolis,
MN, Burgess Publishing Co., p. 286.
Rudolph, W. 1953. Industrial Wastes
Their Disposal and Treatment. New
York, Reinhold Publishing Corp.
Schant, G.G. May 1939. Fish Catas-
trophies During Drought. Journal of
American Water Works Association.
31(5):771.
Schofield, R.U. 1939. The Electrical
Charge on Clay Particle Soils and
Fertilizer. Commonwealth Bureau.
Soil Science. 2:1-5.
Taras, M.J. 1971. Cyanide. (Ed) In
Standard Methods for the Examination
of Water and Waste Water. 13th Ed.
American Public Health Association,
New York, p. 397-406.
223
-------
CONTAMINANT ATTENUATION - DISPERSED SOIL STUDIES
F.A. Rovers*. H. Mooij, and G.J. Farquhar
*Department of Civil Engineering
University of Ottawa
Ottawa, Canada
ABSTRACT
Traditionally the approach to the examination of contaminant interaction with soil
has involved soil column experimentation. This paper presents the results of a. study
evaluating the attentuation of two liquid industrial wastes in soils typical of the
Ontario environment using a dispersed soil methodology which was shown to be suitable for
use to approximate the behavior of contaminants in soil. The liquid industrial wastes,
supplied by the Ontario Ministry of the Environment, were two steel plant wastes - Stret-
ford Liquor and Alkaline Cleansing Liquid Waste. Subsequent to characterization of the
soil and the liquid industrial waste, the attenuation of the liquid waste in the soil was
examined in a sorption and desorption phase. In the sorption phase the amount of con-
taminants attenuated were calculated while the amount and extent of contaminant release
was calculated in the desorption phase. The results of the dispersed soil studies were
used as input to a Soil-Waste Interaction Matrix for environmental assessment and as a
design tool to project contaminant concentrations in a simplified hydrogeologic environ-
ment under a given geometry of liquid waste application to the soil.
INTRODUCTION
Environmental legislation in Canada
currently limits the discharge of solid or
liquid industrial waste to the land to those
sites where it has been demonstrated that a
minimal environmental impact will be
effected. Historically, the soil has proven
to be an acceptable waste recepticle. En-
vironmental impact resulting from the dis-
charge of leachate from a solid waste or
from the infiltration of a liquid waste in-
to soils at a disposal site has to date
generally been of an aesthetic nature rather
than one of receiving water quality degra-
dation. The capacity of the soil to
attenuate contaminants by the physical,
chemical and biological processes described
by mechanical filtration, precipitation and
co-precipitation, sorption, gaseous ex-
change, diffusion and dispersion, and micro-
bial activity, is held to have controlled
contaminant migration to within acceptable
distances.
However, the scientific technology to
assess or predict the attenuation capacity
of a soil is only now being developed. En-
vironmentalists argue that this information
is needed in order to adequately assess the
environmental suitability of a waste dis-
posal system.
Contaminant interaction with soil has
been studied in many research programmes (1,
2,3,4). These were intended to provide in-
put data for the modelling of contaminant
migration in soil. The U.S. Environmental
Protection Agency intends that the input
data be collected using a standard pro-
cedure for the evaluation of the soils con-
taminant attenuation capacity (5).
Recognizing the need to develop a
methodology for assessing an industrial
waste disposal site suitability, relative
to other proposed sites, the Solid Waste
Management Branch of Environment Canada has
also been working towards the development
of a standard environmental assessment
224
-------
procedure, for the use by provincial pollu-
tion control agencies. The procedure now
being finalized would enable regulatory
agencies to evaluate a number of alternate
waste disposal sites based on a simple, yet
comprehensive, waste-soil site rating
scheme. The procedure will involve the use
of soil-waste interaction matrices for the
purpose of rating proposed sites for en-
vironmental acceptability based on a number
of criteria, and for the purpose of pre-
dicting the attenuation and mobility of
industrial wastes in soils.
The examination of contaminant inter-
action with the soil has been studied by
Farquhar and Rovers (1) using a dispersed
soil methodology. The research showed
"that the dispersed soil experiments can be
used to approximate the behavior of con-
taminants in soil" when flow conditions in
the field would be intergranular. The use
of a dispersed soil model wherein an in-
stantaneous well mixed condition exists
also has been found to be suitable for use
in mathematical modelling (6).
The purpose of this paper is threefold.
Firstly, the paper describes the develop-
ment of a standard environmental assessment
procedure suitable for alternate waste dis-
posal site evaluation. Secondly, the paper
describes the attenuation and desorption
characteristics of two liquid industrial
wastes, Stretford liquor and alkaline
cleansing waste, on three soils typical of
the Ontario environment. Thirdly, the
paper describes the use of the attenuation
and desorption data as input to a standard
environmental assessment procedure and the
use of the data in design to evaluate the
zone of influence of a liquid waste dis-
posal on land system.
ENVIRONMENTAL ASSESSMENT PROCEDURE
Soil-Waste Interaction Matrix Procedure
(SWIMP)
The environmental assessment procedure
being developed has been named the SOIL-
WASTE INTERACTION MATRIX PROCEDURE (SWIMP).
A site dependent matrix is being con-
structed using columns of soil-site para-
meters and rows of waste characterization
parameters. The basic structure of the
matrix is depicted in Figure 1.
SOIL-SITE PARAMETERS
SCII.
CTOJP
IT.DEtQlOC*
CRCUP
SITE
CROttf
FIGURE 1. SOIL-VIASTE INTERACTION MATRIX
(SITE DEPENDENT)
This matrix may be used as follows.
Matrix inputs are generated by determining
parameter values, for a given waste and a
given site, in points or arbitrary units.
These values are entered into the matrix as
shown in Figure 2. Waste parameter values
SOll, SITE PARAMETERS
KEY: x - waste parameter value
y - soil-site parameter value
ry •• matrix interaction element
FIGU11K 2. SWIMP (SOIL-WASTE INTERACTION MATRIX PROCEDURE)
are combined with soil-site parameters to
provide matrix interaction elements. The
sum of the matrix elements may be used to
provide an overall point score for com-
parison either with other point scores, or
with a scale of arbitrary acceptability.
225
-------
As a sub-set of this site dependent
matrix, a site independent matrix is also
being developed. This matrix consists of
columns of soil types and rows of waste com-
position parameters. A matrix entry is
essentially a soil attenuation factor, as
shown in Figure 3.
SOIL TYPES
O
t-
cn CNS
I 16.96
16.96 gm CNS attenuated
IOOO gm soil "A"
Figure 3. SITE INDEPENDENT MATRIX
Matrix entries are attainable from
past or current soil-waste interaction
studies, or possibly from field data which
is being collected routinely by pollution
control agencies. In time, the matrix may
become entirely filled using results from
dispersed soil study techniques such as
have been developed by Farquhar and
Rovers (1).
The attenuation information which is
intended to be input into the site depen-
dent matrix can be used in two ways. First
of all, the information can be used to cal-
culate an attenuation parameter value as an
input to the site dependent matrix. Once
the best site is chosen, the information
from dispersed soil studies can be reworked,
as will be discussed later, to assist in
site design and contaminant migration
modelling for the chosen site.
DISPERSED SOIL STUDIES
Methodology
The dispersed soil methodology used to
investigate the contaminant interaction of
the liquid waste, Stretford liquor and
alkaline cleansing waste, with soil has
previously been detailed (1). The develop-
ment and evaluation of the dispersed soil
methodology was done in experiments employ-
ing sanitary landfill leachate.
For each industrial waste 3 sets of 5
reactors, one for each of the 3 soils used,
were placed in series and prepared by
placing 200 gm of air dry soil in the re-
actor, bringing the soils to "field capa-
city" through the addition of groundwater,
purging the reactor with nitrogen and
sealing from the environment.
In the sequence of 5 reactors per
soil, 200 ml of industrial liquid waste was
added to the first reactor and mixed. The
liquid after chemical equilibrium in the
reactor had been reached was then drained
from the soil which was then passed on to
the next of the 5 reactors in series. An
aliquot of the filtrate was taken for
chemical analysis following drainage from
the first, third and last reactor.
Subsequently a total of 5 slugs, each
of 200 ml volume, of groundwater was passed
through the 5 reactor series to evaluate
the desorption of contaminants attenuated.
Figure 4 schematically presents the
dispersed soil study model.
Sequential addition of I, 200 ml volume, slug of
industrial waste followed by 5 slugs, ZOO mi volume,
of desorption water
I
R
E
A
T '
0
R
///
S .
— »
R
E
A
T2
0
R
///
^
~k
R
e
A
C 3
T
0
R
///
, t
(
|
R
E
A
C 4
5
R
',' '/
' L_
i
R
L
5
R
///
1
I \200 gm oir dry soil
\ wetted to field copocity
\Sequential addition of filtrate minus aliquot for
analysis to next reactor in series
i Sequential removal of on aliquot of contacted industrial waste
and desorption water for chemical analysis
Figure 4. SCHEMATIC OF DISPERSED SOIL
STUDY MODEL
Table 1 shows the sequence of experi-
mental activities per single soil per
single industrial waste.
226
-------
TABLE 1. SEQUENCE OF EXPERIMENTAL
ACTIVITIES
TABLE 2. SOIL CHARACTERIZATION-CHEMICAL
AND PHYSICAL
Sequential Sorption
Activities Slug
1
2
3
4
5
6
7
8
9
10
11
1
Rl#
R2 Rl*
R3# R2
R4 R3*
R5* R4
R5*
- -
- -
_ _
-
- -
Desorption
Slug Number
2
_
R1+
R2
R3+
R4
R5+
-
_
-
-
3
_
_
R1+
R2
R3+
R4
R5+
_
-
-
4
_
_
_
R1+
R2
R3+
R4
R5+
-
-
5
_
_
_
_
R1+
R2
R3+
R4
R5+
-
Rl denotes reactor 1.
//detailed chemical analysis of post-
contact liquid waste
*detailed chemical analysis of post-
contact desorption liquid
+partial chemical analysis of post-contact
desorption liquid
Experimental Materials
Soil
Three soils, selected to exhibit a
typical range of fine grained soils re-
presentative of Southern Ontario, were con-
tacted with the industrial liquid waste.
The soils range was selective to fine
grained ice-contact soils deposited by the
last period of glaciation in Southern
Ontario. Present knowledge indicates that
fine-grained soils are best suited for
liquid waste disposal.
The soil characteristics prior to
contact with the liquid waste are presen-
ted in Tables 2 and 3. Table 2 presents
the grain size, cation exchange capacity
and moisture content of the soils while
Table 3 presents the mineralogical
character of the soil.
Industrial Waste
Two industrial liquid wastes from a
steel plant, Stretford liquor and alkaline
cleansing wastes, were contacted with the
three soils. Table 4 presents the quality
characteristics of the liquid waste con-
sidered to be of most concern and given
primary consideration in the sorption and
desportion studies.
Soil
Soil 'jwj-j-
Character
Grain Size-Clay
-Silt
-Sand
Soil Type
Soil 1
4%
65%
31%
Silty
Loam
Soil 2
10%
59%
31%
Silty
Loam
Soil 3
28%
66%
6%
Silty
Clay
Loam
Cation Exchange
Capacity meq/100
gm
Moisture Content
2.27
8.04%
3.89
7.1%
10.52
19.01%
TABLE 3. SOIL MINEROLOGY
Soil 1
Soil 2
Soil 3
u
M
a
X
X
X
w
H
H
^j
M
>
w
H
M
<&
O
O
L
X
X
w
E-i
H
O
O
X
X
X
H
H
M
O
. 1
M
O
g
i
w
H
H
Pi
O
0
ND
ND
ND
H
H
M
O
. T
s
O
g
i
ND
ND
ND
w
H
M
£3
l-l
g
ss
X
X
X
sa
PM
en
Q
S
ND
ND
ND
w
g
N PQ
H H
"^ PH
8- <
L ND
L ND
L ND
W
H
1-1
^
u
H
§
>
ND
ND
ND
X - dominant; L - present; ND - not
detected
DATA ANALYSIS AND INTERPRETATION
Calculation
The chemical data describing the
changes in contaminant concentration dur-
ing the migration of the liquid waste and
desportion water through the dispersed
soil reactors were used to calculate:
1. the net attenuation of each contamin-
ant by all processes including dilution.
2. the net attentuation minus the effect
of dilution for each contaminant, and
3. the net desorption for each contamin-
ant.
The liquid waste and desorption water
upon being mixed with the moist sample is
diluted initially by the soil moisture.
In the field situation diffusion and dis-
persion would result in a similar effect
being imparted on the migrating contamin-
ant. However the magnitude of the effect
227
-------
TABLE 4. CHEMICAL PARAMETERS STUDIED IN
DEPTH IN THE LIQUID WASTE
STRETFORD LIQUOR
*total solids =288,000 mg/1
chemical oxygen demand(COD)= 15,000 mg/1
*total organic carbon (TOG) = 28,800 mg/1
*thiosulphate (S203> = 36,750 mg/1
*thiocyanide (CNS) =140,500 mg/1
*sulphate (804) = 12,818 mg/1
*sodium (Na) = 86,000 mg/1
*total iron (Fe) = 84 mg/1
*vanadium (V) = 90 mg/1
*lead (Pb) =3.2 mg/1
*Cadmium (Cd) = .460 mg/1
ALKALINE CLEANSING WASTE
*total solids = 50,000 mg/1
chemical oxygen demand(COD)= 6,500 mg/1
*total organic carbon (TOC) = 3,800 mg/1
*total phosphorus (P) = 720 mg/1
*sulphate (S04) = 19,135 mg/1
*pH = 13.1
*total iron (Fe) = 520 mg/1
*total manganese (Mn) = 46 mg/1
*sodium (Na) = 24,000 mg/1
*Aluminum (Al) = 13.00 mg/1
Characteristics given primary considera-
tion in the sorption and desorption
studies.
would be less. Therefore the dispersed
soil data would be corrected to account for
this difference. This is discussed further
on in the report. Therefore, in this paper
the field mechanism of diffusion and dis-
persion is related to the mechanism of di-
lution effected in the dispersed soil test.
In both cases the effect is to decrease the
contaminant concentration.
The calculation of the net attenuation
of a contaminant at each point in the dis-
persed soil reactor series was calculated
as
AN,D
~ M
(1)
where
M_.,
= net attentuation including di-
lution - mg contaminant per gm
soil
= mass of contaminant having
potential as effluent - mg
= mass of contaminant in
effluent - mg
Mj = mass of contaminant in influent-
nig
Wg = dry weight of soil - gms
where
-------
graphical form as C/C versus SM/VLW or
with dilution included where:
C = concentration of contaminant
after contact with soil in batch
reactor - mg/1
C = initial concentration of contami-
nant in liquid waste influent -
mg/1
SM
—— = gms soil per ml liquid waste
LW
SM
—— = gms soil per ml desorbing water.
DW
where
= volume of influent liquid
' waste - ml
= PSV - Vs
p = porosity
= volume of soil - cc
= concentration of contaminant in
soil water volume preceding the
addition of V, N - mg/1
= soil water volume available as
dilution water - mis
pE = effective porosity or pore
space
- psv - vs
"V
S,E
The dispersed soil reactors permit the
complete intermixing of the soil water and
the influent liquid waste. Therefore for a
known volume of liquid waste and soil and a
measured moisture content of the soil the
diluted concentration of an influent con-
taminant can be calculated from the dis-
persed soil reactor. This was given by:
vici
Vs
+ V
In a field situation where a volume of
liquid waste is allowed to contact a cer-
tain mass of soil the average effluent con-
centration of the leachate would be calcu-
lated somewhat differently. Dispersion and
diffusion in the field (or undisturbed
column) differs from that of the dilution
provided in the dispersed soil reactors (1).
In the field situation, "dilution" is pro-
vided by the effective moisture content
where the volume of liquid waste being
"diluted" equals the effective pore space,
pE, in an incremental soil volume. This
represents a mixing ratio. In effect the
liquid waste is routed through the soil
volume with the average effluent contamin-
ant concentration given by:
c . rVI.l'CI+VS.E'CS.o ,
E"[ VI,1+VS,E
i.z
ci
VS.EXCS,1
It has been shown that the predicted
breakthrough curve differs from the
observed breakthrough curve for chloride
(Cl) (1) . The predicted breakthrough curve
is calculated on the assumption that the
total volume of soil water is available for
"dilution" of the contaminant concentration
while in fact this is not the case in the
field or an undisturbed column. Therefore,
the predicted attenuation is greater than
that measured.
In the dispersed soil reactors all of
the soil water volume acts to dilute the
contaminant concentration. Therefore, the
effluent contaminant concentration measured
in the batch reactor is less than that
which would be measured in the field.
In order that the changes in the
liquid waste chemistry can be related to a
field situation, an empirical correction
factor, fg, must be used. This factor cor-
rects the contaminant concentration
measured by the dispersed soil technique to
correspond to the field situation or an un-
disturbed soil column where the diluting
mechanism is diffusion-dispersion.
It accounts for two (2) conditions:
(1) that, in the dispersed soil reactor,
the liquid waste and the soil water are not
mixed in the proportions existing in the
field and (2) that the intermixing of con-
stituents between the liquid waste and the
soil water, while virtually complete in the
dispersed soil reactor, may not be so in
the field.
I.N
S.E
I,N
_
^i
pE
To this point in time it has not been
possible to predict values for f£. For
this research then, it was necessary to
make use of existing experimental data col-
lected under varying conditions (1) to
229
-------
determine values of fg.
The value of fE equal to .71 was used
for this study.
Data Presentation
For purposes of this paper the data
analysis and discussion will be limited to
the interaction of the Stretford liquor
with the 3 soils. The contaminants con-
sidered included total organic carbon (TOC),
thiosulphate (S203), thiocyanide (CNS),
sodium (Na), total iron (Fe), vanadium (V),
lead (Pb), cadmium (Cd) and chloride (Cl).
Contaminant Attenuation
Tables 5, 6 and 7 summarizes the at-
tenuation and desorption data in the three
soils for the contaminants described above.
The tables show the influence of "dilution"
as a means of attenuation, the principles
of which were set out earlier. The influ-
ence was felt for all contaminants but was
clearly the major attenuation mechanism for
thiosulphate ($203), thiocyanide (CNS) and
sodium (Na). The data also show that other
attenuation mechanisms were operative, the
nature of which is not known but assumed to
have been related to soil-contaminant
interactions.
For the contaminants iron (Fe), vana-
dium (V) and to some degree total organic
carbon (TOC), "dilution" played a minor
role compared to the other mechanisms in-
volved. It was assumed that the formation
and filtration of the iron (Fe) and vana-
dium (V) precipitates would be the major
removal mechanism.
The removal mechanisms for total
organic carbon (TOC) in part would be via
some biological degradation but because of
the short duration of the tests biological
decomposition was not felt to be fully
developed. Therefore the primary attenu-
ation mechanism was thought to be sorption
of the organics onto the soil.
Tables 5, 6 and 7 show that as the
clay content of the soil increases the
amount of thiosulphate ($203), thiocyanide
(CNS), iron (Fe) and vanadium (V) attenua-
ted by mechanisms other than "dilution"
also increases. For example, the cumula-
tive net attenuation including "dilution"
of thiocyanide (CNS) is 16.962, 18.431 and
19.456 mg/gm respectively for Soils 1, 2
TABLE 5. CUMULATIVE NET ATTENUATION OF
STRETFORD LIQUOR CONTAMINANTS IN
SOIL 1
Contaminant
S2°3
CNS
Pb
Cd
Fe
V
TOC
Na
Batch
Reactor
Series
R
Dl
D2
D3
D4
D5
R
Dl
D2
D3
D4
D5
R,D1,D2
R,D1,D2
R
Dl
D2
R
Dl
D2
D3
D4
D5
R
Dl
D2
D3
D4
D5
R
Dl
D2
D3
D4
D5
Attenuation
with"Dilu-
tion" mg/gm
5.27
-1.151
- .684
- .176
- .223
16.962
-6.092
-1.108
- .369
- .435
- .301
0
0
.01
- .001
0
.016
- .001
- .001
0
0
0
4.016
- .398
- .225
- .025
- .01
- .058
10.885
-2.5
-1.435
- .79
- .299
- .134
Attenuation
minus "Dilu-
tion" mg/gm
2.00
- .013
0.0
- .04
- .016
1.212
0
0
- .004
- .001
0
0
0
.002
0
0
.014
0
0
0
0
0
1.58
.001
- .001
+ .001
- .005
- .007
1.786
- .008
- .036
0
- .009
.002
and 3. However the cumulative net attenua-
tion minus "dilution" is 1.212, 4.872 and
4.789 mg/gm for thiocyanide (CNS) in Soils
1, 2 and 3.
This trend of increased cumulative net
contaminant attenuation including "dilution"
with increased clay content is compatible
with expectations since clay, of all the
soil types, is considered to be most active
in soil-contaminant interactions.
The data presented for lead (Pb) and
cadmium (Cd) warrant some explanation.
They exhibit no calculated attenuation.
This is not however the case. Since the
230
-------
TABLE 6. CUMULATIVE NET ATTENUATION OF
STRETFORD LIQUOR CONTAMINANTS IN
SOIL 2
TABLE 7. CUMULATIVE NET ATTENUATION OF
STRETFORD LIQUOR CONTAMINANTS IN
SOIL 3
Contaminant
S2°3
CNS
Pb
Cd
Fe
V
TOC
Na
Batch
Reactor
Series
R
Dl
D2
D3
D4
D5
R
Dl
D2
D3
D4
D5
R,D1,D2
R,D1,D2
R
Dl
D2
R
Dl
D2
D3
D4
D5
R
Dl
D2
D3
D4
D5
R
Dl
D2
D3
D4
D5
Attenuation
with "Dilu-
tion'1 mg/gm
5.367
-1.798
-1.032
- .554
- .294
- .123
18.431
-2.958
-1.783
-2.218
- .788
- .397
0
0
.011
- .001
0
.017
- .001
- .001
0
0
0
4.847
- .422
- .302
- .033
- .016
- .06
12.309
-2.453
-1.865
- .865
- .399
- .217
Attenuation
minus "Dilu-
tion" mg/gm
2.617
- .01
- .002
- .001
- .009
0
4.872
0
0
- .001
0
0
0
0
.005
0
0
.016
0
0
0
0
0
3.683
0
- .005
.001
- .002
- .01
5.449
- .005
- .022
.003
- .017
- .004
concentrations in the waste are small, 3.2
mg/1 and 0.46 mg/1 respectively, the masses
attenuated in mg/gm soil are extremely small
numbers and appear as "0" in the tables.
The experimental data showed that the
concentrations of calcium (Ca), magnesium
(Mg) and aluminum (Al) increase during pas-
sage of the industrial wastes through the
soil. This was postulated to be due to the
solubilization of soil constituents and the
release of ions into solution during ion
exchange reactions. This trend is not un-
like that exhibited in the field.
It is to be noted that the soil water
does act to "dilute" the soil constituents
dissolved by the above process. This effect
Contaminant
S2°3
CNS
Pb
Cd
Fe
V
TOC
Na
Batch
Reactor
Series
R
Dl
R
Dl
R,D1
R,D1
R
Dl
R
Dl
R
Dl
R
Dl
Attenuation
with "Dilu-
tion" mg/gm
6.619
- .658
19.456
-3.158
0
0
.014
0
.018
0
4.348
- .452
12.697
-2.289
Attenuation
minus "Dilu-
tion" mg/gm
5.423
- .009
4.789
0
0
0
.009
0
.018
0
2.19
.001
4.819
- .004
of "dilution" was observed to occur for dis-
solved aluminum where the attenuation minus
"dilution" exceeded that of the total at-
tenuation. Only at the time that the cor-
rosive nature of the soil would be decreased
would "dilution" overcome the effect of
solubilization.
Contaminant Desorption
Tables 5, 6 and 7 presents the con-
taminant desorption character of the indus-
trial waste. The desorption experiments are
referred to as Dl through D5 with desorption
indicated by a negative sign (negative
attenuation).
It is seen that some measure of desorp -
tion was experienced for most contaminants.
As might be expected, desorption was exten-
sive for these contaminants for which
"dilution" through interchange between the
waste and the soil water was a major mechan-
ism of concentration reduction. The con-
tinous passage of desorption water eventu-
ally removes all of the contaminants in the
soil. Contaminants exhibiting extensive
"dilution" as described above included
thiosulphate (8203), thiocyanide (CNS) and
sodium (Na) for the Stretford liquor.
Active desorption was not exhibited on
the contaminants for which the attenuation
mechanisms other than "dilution" were pro-
minent. This is most clearly depicted for
vanadium (V) in the Stretford liquor. In
the three soils, the average mass of vana-
dium (V) attenuated across the five reactors
231
-------
was 0.017 mg/gm soil with an average of
0.016 mg/gm soil due to processes other than
"dilution". Correspondingly, almost none of
the contaminant was removed during desorp-
tion. This suggests the presence of a long-
term attenuation mechanism. Similar
characteristics were exhibited for iron(Fe).
The desorption process causes migration
of the contaminants in the down flow direc-
tion. However, even for the actively de-
sorb ing contaminants, the peak concentration
per desorbing slug reduces with increased
desorption.
Projection to Field Condition
Previously the calculation methodology
to plot C/CO versus gm soil/ml of waste was
discussed. The curves generated for sodium
(Na) and vanadium (V) in the Stretford
Liquor passing through Soil 2 are used for
discussion and are presented in Figures 5
and 6 respectively.
Eff/iflittal Cone
1.20
6.00E-OI-
6.00E-OI-
4.00E-OI-
2.00E-OI-
SOIL 2-3 NA
INITIAL CONC-
CALCULATED
BAT I
BAT 2
BAT 3
BAT 4
BAT 5
BAT 6
OOOOO.OOO
0 SORPTION
-I T 1 T
0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00
CM SOIL / ML LEACHATE
FIGURE 5. STRETFORD LIQUOR SORPTION 8 DESORPTION OF
SODIUM IN SOIL 2
Eff/imtiol Cone SOIL 2-3 V
1.20
1.00 -
eooE-a-
6.00E-OI-
4.00E-OI-
2.OOE-OI-
n nn
INITIAL CONC-
CALCULATED
BAT 1
BAT 2
BAT 3
BAT 4
1 BAT 5
\ BAT 6
\
\
\
/^•^^^^
/^ — =J~r~*^:f-*^^^.
ffff ^ DESORPTION
3 /
67
0.00 100 200 300 4.00
CM SOIL / ML LEACHATE
5 00 6 00 7.00 8 00
FIGURE 6 STRETFORD LIQUOR SORPTION 8 DESORPTION OF
VANADIUM IN SOIL 2
As identified previously, the primary
mode of sodium (Na) concentration reduction
in the soil was "dilution". Consequently,
active desorption was also the case. These
observations are clearly shown in Figure 5.
The concentration of the sodium (Na) re-
duced as the slug of Stretford liquor moved
through the soil (as gm soil/ml leachate
increases). Figure 5 also shows the concen-
tration of sodium (Na) as the 5 desorption
slugs (Batch 2 through Batch 6) moved se-
quentially through the soil. Note that the
concentration of sodium (Na) in the soil
reduces with increased desorption. For the
third and successive desorption slugs the
peak concentration of the sodium were not
found in the five reactors used.
In the case where the peak concentra-
tion of the desorption slugs could be plot-
ted the curve could be used to determine the
ratio of gm of soil/ml of leachate, re-
quired to achieve some desirable concentra-
tion. Figure 6 is suitable for this pur-
pose.
The initial concentration of vanadium
(V) in the Stretford liquor was 90 mg/1.
Assuming a tolerable concentration of 9 mg/1
a value of C/CO=0.1 is calculated. Figure 6
shows that a line has been projected hori-
zontally from the ordinate at C/CO=0.1 to
intersect the curve of peak desorption con-
centrations at approximately 2.2 gm soil/ml
of leachate. The interpretation of this
analysis is as follows.
Reference is made to the initial pas-
sage of industrial waste through the soil.
A ratio of 2.2 gm soil/ml of waste fixes a
point in space depending on the amount of
waste applied to the soil. The assumption
is that the soil to waste ratio is indepen-
dent of the geometry of the application of
the waste to the soil.
However, under a given geometry of
application, the ratio of 2.2 gm soil/ml of
waste fixes a point in space some distance
downflow. The distance is determined from
the application geometry and the density of
the soil. The data in Figure 6 shows that
the ratio of C/CO=0.1 occurs between the 2nd
and 3rd desorption slugs at approximately
2.5 slugs. Thus the concentration of 9 mg/1
is reached at the predetermined point down-
flow after 2.5 ml of desorption water per
ml of waste has passed through the soil.
From an assumed 15 foot application of
232
-------
Stretford Liquor to a soil represented by
Soil 2 with an in-plate density of 95 Ibs/
ft^ on a dry weight basis, the vanadium con-
centration downflow from the base to the
landfill can be calculated. From the graphs
of Stretford liquor migration through Soil
2 it is calculated that at a distance of 22
feet from the base of the landfill the con-
centration of vanadium (V) would be 9 mg/1.
Vanadium concentrations at this point have
been reduced to tolerable concentrations.
However, the concentration of other contami-
nants have not been reduced to tolerable
concentration levels.
Table 8 presents the calculated concen-
trations of various contaminants at the dis-
tance of 22 feet from the base of the land-
fill for the above considered disposal of
Stretford liquor. Table 6 indicates that
while the concentration of vanadium (V) at a
distance of 22 feet from the base of the
landfill has reached a tolerable concentra-
tion, the water is highly polluted.
TABLE 8. CALCULATED GROUNDWATER
CONTAMINANT CONCENTRATION
Stretford Liquor Peak Contaminant Concen-
Contaminant trations at Noted Dis-
tance From Base of Fill
mg/1
22 feet
Vanadium
TOC
S203
CNS
Na
Pb
Cd
Fe
9 mg/1
12960
22785
92730
47300
3.14
.3
48.72
The above calculations do not take into
account lateral dispersion of the migrating
contaminants nor microbial decay. This
serves as a factor of safety for the
analyses.
It would be recommended that for pur-
poses of design a factor of safety, maybe
2.0, be applied to the calculations.
CONCLUSIONS
1. "Dilution" is an important mechanism of
attentuation for all of the liquid waste
contaminants. By "dilution" alone or dif-
fusion and dispersion it is possible to
reach a tolerable contaminant concentration
in a hydrogeologic environment downflow
from the point of disposal in land.
The contaminants attenuated primarily
by "dilution" for the Stretford liquor were
thiosulphate ($203), thiocyanide (CNS) and
sodium (Na).
The contaminants which were primarily
attentuated by mechanisms other than "dilu-
tion" were lead (Pb), cadmium (Cd), iron(Fe)
and vanadium (V).
The contaminants attenuated by a com-
bination of "dilution" and other mechanisms
was total organic carbon (TOC).
Contaminants which desorbed during
waste migration through the soil were:
Stretford liquor: calcium (Ca), magnesium
(Mg), aluminum (Al)
Alkaline cleansing: calcium (Ca), magnesium
(Mg), aluminum (Al).
2. Desorption was exhibited by all contami-
nants studied and was most prominent for
those which were attenuated primarily by the
mechanism of "dilution". These include thio-
sulphate (8203), thiocyanide (CNS) and
sodium (Na). However the peak migrating de-
sorption concentration reduces as the amount
of desorption increases. Eventually a toler-
able concentration in the soil water is
reached.
For those contaminants attenuated pri-
marily by mechanisms other than "dilution"
such as iron (Fe) and vanadium (V) desorp-
tion at any time was limited.
It could be anticipated that desorption
processes would be complete over geologic
time spans.
3. Attenuation data collected from the dis-
persed soil experimentation can be used to
project soil water concentrations in a field
situation by the use of a correction factor
fg. While this factor was not determined
for this project, data from parallel experi-
mentation was considered to be suitable.
For design purposes it is suggested
that a factor of safety of 2 be applied to
the experimentally calculated soil water
concentrations downflow from the base of the
disposal site.
The attenuation data also can be used
for input to the SWIMP for the evaluation of
potential disposal sites.
4. The Stretford liquor from a steel plant
could be disposed of on land in an
233
-------
environmentally controlled manner. The
waste loading, opportunity for "dilution" and
subsequent desorption would determine the
time and space parameters defining the zone
of influence of the disposal operation.
5. The zone of influence of the disposal
operation is closely related to the waste
loading. In this regard the data suggests
that a number of small waste disposal sites
with a limited zone of influence are pre-
ferable to a large site with a large zone of
influence. It can be postulated that the
past practice of waste disposal in small
sites may account for the limited environ-
mental impact measured to-date.
REFERENCES
1. Farquhar, G.J. and Rovers, F.A.
"Leachate Attenuation in Undisturbed and
Remoulded Soils", Conference Proceedings
Symposium, Rutgers University, New
Brunswick, New Jersey, March 1975.
2. Personal Communication, EPA, U.S.A.,
Sponsored Study Illinois State Geo-
logical Survey, Urbana, Illinois.
3. Personal Communication, EPA, U.S.A.,
Sponsored Study, University of Arizona,
Arizona.
4. Personal Communication, EPA, U.S.A.,
Sponsored Study, Dugway Proving Grounds,
U.S.A.
5. Personal Communication, EPA, U.S.A.,
Study Session, Washington, December
1975.
6. Oregon State University Environmental
Health Sciences Center Task Force on
Environmentally Hazardous Wastes,
"Disposal of Environmentally Hazardous
Wastes", Oregon State Department of
Environmental Quality, December 1974.
234
-------
ESTIMATION OF NONREACTIVE AND REACTIVE SOLUTE FRONT LOCATIONS IN SOILS
P. S. C. Rao, J. M. Davidson, and L. C. Hammond
Soil Science Department, University of Florida
Gainesville, Florida 32611
ABSTRACT
A technique, based on the physical principles of water and solute transport, was used
to describe the position of nonreactive and/or reactive solute fronts in a soil profile.
The procedure estimates the solute front location after infiltration and redistribution of
the soil water to "field capacity", and includes extraction of soil water by plant roots
between irrigation/rainfall events. Linear equilibrium adsorption-desorption of the reac-
tive solutes was assumed. The approximation procedure was based on the principles that
(i) the soil water residing in all pore sequences participates in the transport processes,
and (ii) the soil water initially present in the profile is completely displaced ahead of
the water entering at the soil surface. An analysis of published field and laboratory
data on infiltration of nonreactive solutes (Cl~ and N0~p indicated that these assumptions
were valid. Agreement between predicted solute front location using a sophisticated one-
dimensional transient flow models and the above procedure further support the validity of
the assumptions. Field data for chloride movement in a sandy soil, in the presence of a
fully established millet crop, during a 60-day period were in agreement with the simpli-
fied model. The major drawback of the present technique is in its failure to describe the
attenuation or spreading of a solute pulse as it is leached through the soil profile.
The movement of chemicals through the
soil is influenced by several physical and
chemical properties of the soil and solute.
Complex interactions between the solute and
soil matrix (hydrodynamic dispersion,
adsorption-desorption, chemical/biological
transformations, etc.) play an important
role in solute mobility and concentration
distribution in the soil profile. Mathe-
matical models and numerical solutions of
these conceptual process-oriented models
are available (3, 9, 12, 15, 16). However,
because of the complexity and number of
input parameters required to solve these
models, they have not been used, in gener-
al, to simulate field cases.
A technique, based on the physical
principles of water and solute transport,
was used to describe the position of non-
reactive and/or reactive solute fronts in
a soil profile. The procedure estimates
the solute front location after infiltra-
tion and redistribution of the soil water
to "field capacity", and includes extrac-
tion of soil water by plant roots between
irrigation/rainfall events. Published data
on solute transport, for laboratory and
field conditions, were used to validate the
model.
COMPUTATIONAL METHODS
The computational techniques presented
here are limited to estimating the position
of an invading solute front. The spreading
of the solute zone behind the front due to
molecular diffusion and convective disper-
sion is not considered here. The technique
is based on the principal assumptions that
(i) the soil water residing in all pore
sequences participates in the transport
processes, and (ii) that the soil water
initially present in the soil profile is
completely displaced ahead of the water
entering at the soil surface. A simple
model for prediction of water and sediment
transport from a watershed was developed
235
-------
(5) based on these assumptions.
Infiltration
Consider the infiltration of an amount
of water, I, into a homogeneous soil pro-
file with a uniform initial soil-water con-
tent fraction of 6^ (cm3/cm3). The depth
to which the wetting front will advance can
be calculated from
wf
0f-9.
5f >9i
[1]
where, dwf is the distance (cm) from the
soil surface to the wetting front, and Qf
is soil water content in the wetted zone
behind the wetting front. For infiltration
of 5 and 10 cm of water into an initially
dry (9-^=0) soil, the wetting front depth
(dwf) would be 14.3 and 28.6 cm, respec-
tively, when 9f=0.35 cm3/cm3 (Figure 1).
However, if 9.^ was 0.10 cm3/cm3 and 9f was
0.35 cm3/cm3, the wetting front would be at
20 and 40 cm, respectively, for 5 and 10 cm
water applications (Figure 2). Therefore,
for a given water application and 9f, the
wetting front depth increases as
creases.
in-
If assumptions (i) and (ii) given
above are valid, then the water at the
observed wetting front for 9i > 0 is the
water initially contained in the soil pro-
file and not that added at the soil sur-
face. Hence, complete displacement of the
initial water (0^ > 0) results in a non-
reactive solute front being located at,
Soil-Water Content
0.0 0.2 0.4
sf e.
[2]
0 40 80
Concentration ( Xcc)
Figure 1. Distribution of water (solid
line) and nonreactive solute (dashed
line) after 5 and 10 cm of water had
infiltrated into an initially dry
(6i=0) soil profile.
where, dg£ is the solute front position
(cm). Solving equation [1] for I and sub-
stituting in equation [2] yields,
sf
or, upon rearrangement,
Asf _ 1 _ 9±
dwf 9f
[3]
3f >ei
Given the values of Qi and 6f, the
apparent retardation of the nonreactive
solute front with respect to the observed
wetting front can be estimated by equation
[4]. Note that the value of the ratio
(dsf/dwf) is equal to 1.0 when 9±=0 (i.e.,
infiltration into dry soil) ; thus the non-
reactive solute front rides on the wetting
front. However, when 6^^ > 0 (i.e., infil-
tration into moist soil), the nonreactive
solute front would lag behind the observed
wetting front [(dsf/dwf) <1]. Equation [4]
is not valid for the case of 9i=9f, as
the ratio (dsf/dwf) is equal to zero.
236
-------
Soil-Water Content
40 80
/ ./wo
Concentration ( *
o
Figure 2. Distribution of water (solid
line) and nonreactive solute (dashed
line) after 5 and 10 cm of water had
infiltrated into a soil profile at a
uniform initial water content (shown
as vertical dashed line) of 0.1 cm /
Note that the nonreactive solute front
position depends on the amount of water
added and the average water content in the
wetted zone behind the wetting front, but
not on the initial water content (Figures 1
and 2). This conclusion is in agreement
with experimental observations of previous
workers (1, 9, 10, 16).
Published data for NOo and Cl~ move-
ment in several soils were used to test the
validity of assumptions (i) and (ii).
These data are presented in Figure 3 using
equation [A]. Considering the wide range
in experimental conditions and that both
laboratory and field data were included,
the agreement between the 1:1 line and the
data is excellent. Apparently, in all the
cases considered, the initial soil water
in the profile was displaced ahead of the
applied water; thus, supporting our prin-
cipal assumptions.
O Balasubromanian, 1974
D Cassel, 1971
O Ghuman et al.t 1975
• Kirda et al , 1973
A Warrick el al., 1971
e,/ef
Figure 3. Comparison of experimentally
measured values (data points) and
calculated values (solid line) of the
ratio dsf/dwf as a function of
It has been suggested that the soil
water within the intra-aggregate micropores
may be excluded from solute transport pro-
cesses; thus, assumption (ii) may not be
valid for well-aggregated soils. Assuming
an analogy between heat and solute transfer
in spheres, the ohapacteTistic time (t0)
required for 99% of the solute to diffuse
out of an aggregate can be calculated by
(13),
to = (0.1012)
[5]
where, d is aggregate diameter (cm), DQ is
molecular diffusion coefficient (cm^/min)
in water, and T is tortuosity factor to
account for intra-aggregate geometry. The
dependence of to on d, as developed in
equation [5] , is graphically presented in
Figure 4 for several values of T. It is
apparent that the characteristic times (to)
are small (< 15 minutes) and that the
influence of T is not significant for small
aggregates (d < 0'2 cm). Other workers
(4, 12) have also reached similar conclu-
sions regarding the significance of aggre-
gate diameter for absorption of water and
diffusion of gases in aggregated media.
237
-------
100
c
I
d.
[7]
.2
AGGREGATE
.4 .6
DIAMETER (cm)
Figure 4. The relationship between aggre-
gate diameter (d) and the character-
istic time (t0) for 99% mass transfer.
Numbers shown along each curve are the
values of intra-aggregate tortuosity
(T).
A chara.oteTi.stic ori.ti.oal velocity
(Vc), above which intra-aggregate diffusion
becomes significant, may be calculated
from:
[6]
The dependence of Vc on d and T is shown in
Figure 5. For aggregates with d < 0.2 cm
(most common size used in laboratory column
studies), it would appear that intra-
aggregate diffusion becomes significant
only when Vc' > A cm/hr. Such velocities
are not generally encountered in most field
or laboratory studies. Thus, it may be
concluded that for most aggregated soils,
all the soil water participates in the
solute transport process.
Redistribution of Soil-Water
At the termination of infiltration,
the soil water content in the wetted zone
decreases due to drainage or redistribution
until the profile attains a "field capaci-
ty" water content (6pc)• The movement of
the solute front due to this process is
determined by the amount of "drainable"
water above the depth dg^. It can be shown
that,
FC
where, dg^ is solute front location after
redistribution, A0=(6f-6FC), and the pro-
duct (dsf) (A9) represents the amount of
"drainable" water above dsf.
AGGREGATE DIAMETER (cm)
Figure 5. The relationship between aggre-
gate diameter (d) and the characteris-
tic critical velocity (Vc). The
numbers shown along each curve are the
values of intra-aggregate tortuosity
factor (T).
Substitution of equation [3] for dsf in
equation [7] yields,
dsf =
[8]
FC
The validity of equation [8] is limited to
the case where the solute front is initi-
ally located at the soil surface (z=0)
prior to infiltration. For a case when the
solute front is located at some depth di
(di > 0) before infiltration, equation [8]
must be modified as,
d' = d. +
sf i
[9]
FC
238
-------
The mobility or depth to which a re-
active solute front penetrates is reduced
due to adsorption-desorption processes.
By assuming a linear and reversible equi-
librium adsorption model, a retardation
factor (R) can be calculated (3),
R
1 +
pk
6FC
[10]
where, p is soil bulk density (g/cm^) , k is
adsorption partition coefficient (cm-V
g) , and Q-pC ls field capacity water content
Equation [9] can be generalized to
predict reactive front locations,
dsf
1 _L_
R 8FC
[11]
where, R is defined by equation [10]. For
a nonreactive solute (k=0) the retardation
factor R=l, and equation [11] reduces to
equation [9]. Note that dsf of a previous
event becomes d^ for the next event.
Plant Root Extraction of Soil Water
Depletion of water by plant roots
creates a soil-water deficit in the profile.
The deficit above the solute front^ denoted
Id, is
/•dsf
Jo
- 6(z)] dz
[13]
where, the water content profile 6(z) is
predicted by equation [12] at any time, and
dsf is defined by equation [11]. The
deficit (I(j) must be satisfied by an input
(I) due to a irrigation/rainfall event
before further movement of the solute front
can occur. Furthermore, the evapotranspi-
ration losses during the redistribution
period, assumed here to be two days, must
also be accounted for in calculating the
"effective" amount of input water (Ie) re-
sulting from a rainfall/irrigation event.
This is done as follows:
Ie = I - [Id + (2)
(T)]
[14]
For the case when the deficit is over-
come by an event (i.e., Ie > 0), the new
location of the solute front may be calcu-
lated as,
Many practical solute transport pro-
blems occur in the presence of a growing
crop. Extraction of water from the root-
ing zone results in a nonuniform water con-
tent profile. Because of this several
modifications must be made in the equations
presented in the preceding sections. The
extraction of soil water by the plant was
simulated by a macroscopic model (11),
36(z.t) _
9t ~ T<
K(6) • A(Z)
Jo K(6>
A(Z) dz
[12]
where, 96/9t represents the change in water
content due to roots K(G) is soil hydraulic
conductivity (cm/hr), A(Z) is effective
plant root absorption function which was
assumed to be proportional to root density
distribution, T is evapotranspiration
demand (cm/hr), and L is the rooting depth.
Equation [12] distributes the evapotran-
spiration demand (T) over the entire root-
ing zone according to the product [A(Z)«
K(9)]. A "static" soil profile is assumed
where the vertical flow of water is ig-
nored.
,
sf
d. +
i
•, I'
R' e
> 0
[15]
However, for the case when an event is not
large enough to overcome the deficit (i.e.,
Ie < 0), there is no additional movement of
the solute front,
d , = d.
sf x
0
[16]
The input water, after adjusting for the
two-day evapotranspiration loss, was dis-
tributed in the soil profile to a depth dx
by successive interations to satisfy the
condition,
(I - 2T) =
FC-9(z)]dz
d < d ,
x - sf
[17]
All calculations involving root ex-
traction were performed on an IBM 360/370
digital computer (FORTRAN IV program).
Average computer costs for a 60-day simula-
tion period were less than five dollars.
239
-------
MODEL VALIDATION
Leaching of a chloride pulse through a
Eustis fine sand field profile, with a
fully established crop of millet (Panioim
milaeeum), was measured (7) during a 60-
day period between August 1-September 24,
1973 at Gainesville, Florida. The chloride
data was used to validate the present
model. Experimentally measured (8) soil
hydraulic conductivity versus soil-water
content for the same field plot was fitted
to the following relationship:
K(6) = Exp [B6a + D] [18]
with B = -3.3471, a = -0.62, and D =
10.1753. The effective root absorption
function, A(z), was assumed to be,
A(z) = Exp [-O.OOSz] - 0.471 [19]
where, z is soil profile depth. Equation
[19] describes an exponential decay root
absorption function, where 39, 28, 19, 11,
and 3% of the total root activity was pre-
sent in each successive 30 cm segments of
the soil profile to 150 cm. The evapotran-
spiration demand (T) was assumed to remain
constant at 0.3 cm/day during the 60-day
simulation period. The rainfall distri-
bution at the experimental site was also
recorded (7), and used as input in the pre-
sent model. The Eustis soil profile
drains to a field capacity (9FC) of 0.08
cm /cm two-days after any input event.
Plant available water was defined to be
that held in the profile between field
capacity (Qp^) and 15-bar value (6-^5=0.03)
water contents.
Experimentally measured (7) field data
for chloride front location and that esti-
mated by the present model are compared in
Figure 6. Considering all the simplifying
assumptions in the model, the agreement
between measured and predicted values is
very good; thus, validating the model.
An exact knowledge of the root absorp-
tion function [A(z)] for a given crop is
often unavailable. In such cases, a uni-
form extraction of soil water throughout
the rooting depth, i.e., A(z)= constant,
may be assumed without introducing serious
error in the prediction of solute front
locations. The magnitude of such error
was between 5-15% for the case of Cl~ move-
ment in Eustis sand (data of Figure 6).
II '
1
1
1 1
1
-
-
-
-
.
u
i "E
o
2 —
3 1-
4 0.
Z
5 -
=100
o
Ifl
O 50
a.
uj
o
predicted
measured
20 30 40 50
TIME, days
60
Figure 6. Comparison of the Cl~ front loca-
tions predicted (solid lines connect-
ing open circles) and those experi-
mentally measured (closed circles) on
a Eustis fine sand profile with a
fully grown crop of millet.
The influence of adsorption-desorption
processes in retarding the movement of a
reactive solute is demonstrated in Figure
7. The rainfall distribution data, K(6),
and A(z) functions were identical to those
used in Figure 6. A value of R=l repre-
sents the case of no adsorption (nonreac-
tive solutes), while R=2 and 4 represent
the case of reactive solutes. From the
curves shown in Figure 7, it is apparent
that the efficiency of any given rainfall
event in moving the solute front decreased
as R increased (see Eq. 11). Since the
reactive solute front remains closer to the
soil surface than a nonreactive solute
front, a larger fraction of the water input
may be effective in leaching the reactive
solute. However, a given amount of water
input is four-times less efficient (for R=
4) in moving the reactive solute front than
a nonreactive solute front (R=l). This
results in the reactive solute front move-
ment being retarded as shown in Figure 7.
240
-------
E
o
-
i
;
•11
.
-
-
u
A
E
2 ~y
3 —
tu
'c
55
20 40
TIME (days)
60
Figure 7. Influence of adsorption-
desorption processes in retarding the
reactive solute front movement in a
soil profile. R=l represents the
nonreactive solutes.
DISCUSSION
The model presented here is intended
to be a management model, which estimates
the solute front position. The procedure
does not predict the solute concentration
distribution in the soil profile. The
model is limited to the case of homogen-
eous, well-drained soil profiles. Cases
where the soil profile is layered or the
water table is close to the soil surface
were not considered in the present model.
However, based on transport studies for
reactive solutes through multi-layered
soils (15), the proposed model could be
adapted to predict the time of arrival of
the solute front at a given depth (such as
at the water table) by obtaining a
weighted-mean of the retardation factors
for each soil layer.
The adsorption of the reactive so-
lutes was assumed to be described by a
linear adsorption isotherm. When the ad-
sorption isotherm is nonlinear, the
retardation factor (R) is not a constant
as shown in eq. [10], but is concentra-
tion-dependent. However, a weighted-mean
R value may be used (14) to predict the
movement of reactive solute fronts.
Two additional processes not accounted
for in the present model are (i) plant
uptake of the solutes, and (ii) chemical
and/or microbiological transformations of
the solutes. Efforts are currently under-
way in our laboratory to improve the pre-
sent model capabilities by incorporating
both these processes.
ACKNOWLEDGMENTS
This research was supported in part by
the U.S. Environmental Protection Agency
Grant No. R-803849-01 and in part by
special funds from the Center for Environ-
mental Programs of the Institute of Food
and Agricultural Sciences. Florida Agr.
Exp. Sta. Journal Series No. 9018. The
authors acknowledge the assistance of Mr.
R. E. Jessup in development of the computer
program.
REFERENCES
1. Balasubramanian, V. 1974. Adsorption,
denitrification, and movement of
applied ammonium and nitrate in
Hawaiian soils. Ph.D. Dissertation,
University of Hawaii. Diss. Abstr.
Internl.
2. Cassel, D. K. 1971. Water and solute
movement in Svea loam for two water
management regimes. Soil Sci. Soc.
Amer. Proc. 35:859-866.
3. Davidson, J. M., Li-Tse Ou, and P. S.
C. Rao. 1976. Behavior of high pes-
ticide concentrations in soil-water
systems. Proc. of Hazardous Waste
Research Symposium, U.S. E.P.A. and
Univ. of Arizona, Feb. 2-4, 1976,
Tucson, Arizona.
4. Farrell, D. A. and W. E. Larson. 1973.
Effects of intra-aggregate diffusion
on oscillatory flow dispersion in ag-
gregated media. Water Resour. Res.
9:185-193.
5. Frere, M. H. 1975. Integrating che-
mical factors with water and sediment
transport from a watershed. J.
Environ. Qual. 4:14-17.
6. Ghuman, B. S., S. M. Verma, and S. S.
Prihar. 1975. Effect of application
rate, initial soil wetness, and re-
241
-------
distribution time on salt displacement
by water. Soil Sci. Soc. Amer. Proc.
39:7-10.
7. Graetz, D. A., L. C. Hammond, and J.
M. Davidson. 1973. Nitrate movement
in a Eustis sand planted to millet.
Soil and Crop Sci. Soc. of Florida
Proc. 33:157-160.
8. Hammond, L. C., J. M. Davidson, and
D. A. Graetz. 1972. Unpublished
data, Florida Agr. Exp. Sta.
9. Kirda, C.j D. R. Nielsen, and J. W.
Biggar. 1973. Simultaneous trans-
port of chloride and water during
infiltration. Soil Sci. Soc. Amer.
Proc. 37:339-345.
10. Kirda, C., D. R. Nielsen, and J. W.
Biggar. 1974. The combined effects
of infiltration and redistribution on
leaching. Soil Sci. 117:323-330.
11. Molz, F. J. and I. Remson. 1970.
Extraction term models of soil mois-
ture use by transpiring plants.
Water Resour. Res. 6:1346-1356.
12. Philip, J. R. 1968. Theory of ab-
sorption in aggregated media. Aust.
J. Soil Sci. 6:1-19.
13. Rao, P. S. C. 1974. Pore-geometry
effects on solute dispersion in aggre-
gated soils and evaluation of a pre-
dictive model. Ph.D. Dissertation.
University of Hawaii. Diss. Abstr.
Internl. 36(2):527-B.
14. Rao, P. S. C. and R. E. Green. 1976.
Quantitative evaluation of non-
solvent fraction of soil water. Soil
Sci. Soc. Amer. J. (in press).
15. Selim, H. M., J. M. Davidson, and P.
S. C. Rao. 1976. Transport of reac-
tive solutes through multilayered
soils. Soil Sci. Soc. Amer. J. (in
press).
16. Warrick, A. W., J. W. Biggar, and D.
R. Nielsen. 1971. Simultaneous
solute and water transfer for an un-
saturated soil. Water Resour. Res.
7:1216-1225.
242
-------
TRACE ELEMENT MIGRATION IN SOILS:
DESORPTION OF ATTENUATED IONS AND EFFECTS OF SOLUTION FLUX
N.E. Korte1, W.H. Fuller, E.E. Niebla, J. Skopp2, and B.A. Alesii
Department of Soils, Water, and Engineering
The University of Arizona
Tucson, Arizona 85721
ABSTRACT
A leachate from a simulated sanitary landfill was individually spiked with ten trace
elements (As, Cd, Cr, Cu, Hg, Ni, Pb, Se, V, Zn) and used to leach eleven soils from the
seven most prominent orders. When the leaching was concluded, each soil column was seg-
mented into ten sections which were extracted with water and with 0.1 N_ HC1. Results
indicate that the ions sorbed initially were retained most tightly, and that coarse tex-
tured soils most easily release sorbed ions. Extraction with water releases only a
minimal quantity of attenuated ions. Dilute acid leaching, in contrast, dissolves sig-
nificant quantities of sorbed ions even though it is preceded by complete drying of the
soil. Additionally, the leaching work displayed a dependence of the mobility of certain
ions to changes in flow rate. Accordingly, preliminary data are presented which demon-
strate the potential of controlling solution flux in order to optimize trace element
attenuation.
INTRODUCTION
Land disposal of municipal and indus-
trial wastes is increasing rapidly (U.S.
EPA 1973). These wastes may contain
potentially hazardous concentrations of
toxic materials (Ross 1968, Nemerov 1971).
Much current effort, therefore, has focused
on the ultimate fate of trace contaminants
in the environment (Page 1974, Lisk 1972).
In a previous report (Korte et al.
1976) equations were developed to predict
the movement of eight trace elements (As,
Be, Cd, Cr, Ni, Se, V, Zn) through soils
with varying properties. Where the depen-
dent variables were clay content, surface
area, and the content of free iron oxides,
-'-Current address, University Analytical
Center, University of Arizona, Tucson,
Arizona 85721.
2Current address, Department of Soil
Science, University of Wisconsin, Madison,
Wisconsin 53706.
predictive equations were significant at
the 99% confidence interval for the migra-
tion of Cd, Be, Zn, and Ni, and at the 95%
interval for As and V. By including pH as
a dependent variable the prediction of Cr
and Se was significant at the 95% level.
Cu and Pb did not migrate through the soil
columns so their behavior in the time frame
of that experiment was unrelated to soil
properties.
Despite statistical correlations,
actual mechanisms usually have not been
identified. This fact, coupled with demon-
strations that soils can release potential
pollutants when leached with various solu-
tions (Fuller et al. 1976), indicates that
the permanence of land disposal is unknown.
Rouston and Wildung (1969) suggested the
non-permanence of land disposal, but quan-
titative data are lacking.
243
-------
Extraction Studies
Studies of Solution Flux
One way to evaluate the permanence of
ion attenuation is by relating it to the
efficiency of extraction techniques. The
availability of trace metals for plant
growth has long been determined by extrac-
tion (Black 1965, Walsh and Beaton 1973,
Krauskopf 1972). Since mild extractants
reflect plant availability better than
total analyses (Ivanov 1969), it follows
that conditions of natural leaching are
best simulated by a mild extractant. In-
deed, to determine what portion of attenu-
ated metal ions are subject to leaching by
rain water, extraction with water would be
useful.
Extractions with harsher reagents also
can provide important information. Simple
"input-output" data do not completely des-
cribe an element's migration. A major
shortcoming is encountered if none of the
element passes through the soil column
during the experiment. It is then impos-
sible to determine if the soil's charac-
teristics are affecting the ion's movement.
In any case, knowledge of the distribution
of a sorbed element in a profile or soil
column yields greater insight into the
soil's capacity for retention of the ele-
ment.
Quantitative interpretation of extrac-
tion data, however, must be made cautiously.
Hodgson (1960) showed that heavy metal
sorption is not completely reversible. In
his experiment, non-extractable, sorbed Co
was considered to be a result of inter-
lattice penetration. It is clear that what-
ever mechanisms are involved, depending
upon the capacity and thermodynamic favor-
ability of competing sorbing reactions, an
extractant would remove different percen-
tages of sorbed material from varying
depths in a soil column or profile.
Therefore, the objective of this work
was to determine the distribution of ten
sorbed elements (As, Cd, Cr, Cu, Hg, Pb,
Ni, Se, V, Zn) in soil columns by means of
both a water and dilute acid extraction.
These data provide quantitative information
on the potential for desorption of the
attenuated ions, as well as further veri-
fication of the role of soil properties
in trace element attenuation.
It has been previously emphasized that
little in known about actual mechanisms
(Fuller and Korte 1975) of trace element
attenuation. Soil texture has been repeat-
edly singled out as an important factor in
trace element migration. However, whether
this is due primarily to surface effects
or the consequent effects on flow has not
been characterized. Previous work, especi-
ally by Biggar and Nielsen in 1960, has
indicated that the migration of ions is
strongly influenced by the flow rate of the
leaching solution. Leaching studies in
this laboratory using a conventional con-
stant head arrangement resulted in pseudo-
steady-state flow conditions. Small changes
in flow due primarily to trapped gas caused
an erratic output. Accordingly, experiments
were begun to examine the effects of solu-
tion flux or flow rate on a trace element's
migration.
METHODS AND PROCEDURES
Extractions
Ten sorbed trace elements (As, Cd, Cr,
Cu, Hg, Ni, Pb, Se, V, Zn) were extracted
from soil columns which had been leached
with a natural leachate individually spiked
with each element. The natural leachate
was effluent from a simulated sanitary land-
fill (Korte, Niebla and Fuller 1976). Trace
element concentrations were from 70 to 120
ppm and a leaching rate of 1/2 to 1 pore
volume per day was continued for 25 to 30
days. Complete details with respect to
apparatus and procedures have been provided
elsewhere (Korte et al. 1976).
Eleven soils representing the seven
most prominent orders were used in these
experiments. Their pertinent characteris-
tics are listed in Table 1. A complete
discussion of the soils and their properties
has been reported by Fuller et al. (1976).
At the conclusion of the leaching ex-
periments the 5 x 10 cm soil columns were
segmented into ten 1-cm sections. Each
segment was oven-dried so that a material
balance could be easily calculated so that
no variations in moisture content would be
244
-------
Table 1. CHARACTERISTICS OF THE SOILS'
Soil
Location
Wagram
(N. Carolina)
Ava
(Illinois)
Kalkaska
(Michigan)
Davidson
(N. Carolina)
Molokai
(Hawaii)
Chalmers
(Indiana)
Nicholson
(Kentucky)
Fanno
(Arizona)
Mohave
(Arizona)
(Arizona)
Anthony
(Arizona)
Soil
Order
Ultisol
Alfisol
Spodosol
Ultisol
Oxisol
Mollisol
Alfisol
Alfisol
Aridisol
Aridisol
Entisol
PH
4.2
4.5
4.7
6.2
6.2
6.6
6.7
7.0
7.3
7.8
7.8
CEC
meq/lOOg
2
19
10
9
14
26
37
33
10
12
6
EC
ymhos/cm
225
157
237
169
1262
288
176
392
615
510
328
Surface
Area
m2
8.0
61.5
8.9
51.3
67.3
125.6
120.5
122.1
38.3
127.5
19.8
Free
Iron
Oxides
%
0.6
4.0
1.8
17.0
23.0
3.1
5.6
3.7
1.7
2.5
1.8
Total
Mn Sand Silt
ppm % %
50 88 8
360 10 60
80 91 4
4100 19 20
7400 23 25
330 7 58
950 3 47
280 35 19
825 52 37
770 32 28
275 71 14
Texture
Clay Class
%
loamy
4 sand
silty
31 clay
loam
5 sand
61 clay
52 clay
silty
35 clay
loam
silty
49 clay
46 clay
sandy
11 loam
clay
40 loam
sandy
15 loam
Predominant
Clay Minerals
Kaolinite
Chlorite
Vermiculite
Kaolinite
Chlorite
Kaolinite
Kaolinite
Kaolinite
Gibbsite
Montmorillonite
Vermiculite
Vermiculite
Montmorillonite
Mica
Mica
Kaolinite
Mica
Montmorillonite
Montmorillonite
Mica
* Listed in order of importance
-------
c.
C MAX
ho
-p-
.4 -
.2 -
0 -
4567
COLUMN DEPTH (cm)
8
Figure 1. Extraction of Cd from Wagram, Davidson, and Molokai soils.
-------
c_
C MAX
1.0
.8
.6
.4
.2
0
ZINC
I
I
4567
COLUMN DEPTH (cm)
8
10
Figure 2. Extraction of Zn, Cr, and As from Davidson clay.
-------
c.
CMAX
0 -
O O WAGRAM
A A MOHAVE
FAN NO
4567
COLUMN DEPTH (cm)
8
10
Figure 3. Extraction of Cu from Wagram, Mohave, and Fanno soils.
-------
ho
4>-
VO
c.
C MAX
O O MOHAVE
A A NICHOLSON
MOLOKAI
4567
COLUMN DEPTH (cm)
Figure 4. Extraction of Pb from Mohave, Nicholson, and Molokai soils.
-------
involved. Preliminary results showed that
variations in extractability for dried ver-
sus saturated samples were slight.
Extractions were performed with 0.1 N_
HC1 to obtain a concentration profile of
the element for each soil column, and with
water to simulate natural leaching. Two
grams of dried soil were shaken with 20 ml
of extractant for the experimentally deter-
mined optimum time. Samples were than
centrifuged and filtered. The concentra-
tion of the ion in the supernatant was
measured by atomic absorption spectrometry
and a material balance was calculated.
Solution Flux
For the study of solution flux a uni-
form flow rate was provided by using
Pharmacia (Piscataway, NJ) peristaltic
pumps to add leachates to the soil columns.
These pumps are capable of flow rates as
low as .6 ml/hr with a reproducibility of
*1%. Samples were collected with a frac-
tion collector so that both the flow rate
and the trace element concentration could
be carefully monitored.
RESULTS AND DISCUSSION
Dilute Acid Extractions
The nature of all soil-trace element
relationships when extracting with 0.1 N_
HC1 is represented by the curves in Figures
1 and 2. Cmax is the maximum concentration
in any column segment as determined by the
0.1 N HC1 extraction, and C is the concen-
tration determined at other column depths.
Almost invariably, Cmax was the concentra-
tion determined from the top segment of
the column. By plotting the dimensionless
quantity C/Cmax versus depth, curves for
different columns can be easily compared
despite variations in concentration among
the columns.
Cadmium was not detected in the
effluent from the Molokai soil column as
evidenced by no Cd being extracted from the
last portion of the column (Figure 1).
Cadmium breakthrough (effluent cone =
influent cone) with Wagram loamy sand is
typified by the horizontal portion of the
extraction profile. With Davidson clay,
the concentration in the effluent leveled
off below C/Co (effluent cone/influent cone)
= 1.
This range of behavior, as shown in
Figure 1, was followed for each soil col-
umn and was observed not only for a parti-
cular element but also for individual soils
(Figure 2). Arsenic was fully retained
by Davidson clay, the Zn concentration in
the effluent equaled the influent, and Cr
attained a steady-state where the influent
concentration remained less than the ef-
fluent.
Copper and Pb were so immobile in the
soils studied that, from input-output data
alone, differences due to soil properties
could not be distinguished. Some results
for the dilute acid extraction for Cu and
Pb are shown in Figures 3 and 4. Although
the amount of leachate added to each column
was similar, there are obvious variations
among the soils. Copper was extracted from
Wagram loamy sand as deep as 6 cm, but from
Fanno silty clay only as deep as 3 cm
(Figure 3). Soil texture and its consequent
effects on flow obviously play a significant
role in the migration of Cu and Pb. Had
the soil columns been leached long enough,
the effect of soil properties on migration
of Cu and Pb could have been shown by moni-
toring the effluent as was done for other
divalent cations. These results suggest
that the behavior of Cu and Pb could be
added to Cd, Ni, Be, and Zn as divalent
cations whose movement is best estimated
by knowledge of surface area, clay content,
and the content of free iron oxides.
Relatively large quantities of sorbed
material were extracted by the 0.1 N_ HC1.
All of the attenuated ion was removed in
some instances (Table 2). Cd, Zn, and Ni.
were easiest to extract. Furthermore, the
more coarse textured the soil, the greater
the efficiency of extraction, since the
most effective extractions were with the
sandy soils—Anthony, Kalkaska, Mohave and
Wagram. The amount of sorbed Cd removed by
acid extraction for these four soils ranged
from 90 to 100%. For clay soils such as
Davidson, Nicholson, Fanno, and Mohaveca,
the efficiency was 70 to 80%.
Water Extractions
The order of extractability with water
250
-------
Table 2. THE AMOUNT OF SORBED TRACE ELEMENT EXTRACTED BY 0.1 N HC1
Trace Element
Soils
Wagram l.s.
Ava s.c.l.
Kalkaska s.
Davidson c.
Molokai c.
Chalmers s.c.l.
Nicholson si.c.
Fanno c.
Mohave s.l.
Mohaveca c . 1 .
Anthony s.l.
As
11
11
18
5
0
nd
11
24
11
20
13
Cd
90
85
100
77
87
nd
75
80
89
74
100
Cr
8
7
16
7
5
nd
13
8
7
17
100
Cu
60
40
67
67
57
nd
27
44
55
51
68
Hg
-------
was much different than with acid: V > Se
> As ! Cr > Zn > Ni > Cd > Hg > Cu > Pb.
Although this order is highly empirical
the trend is that elements sorbed as anions
are most susceptible to leaching by water.
These results support the work of Jacobs,
Syers, and Keeney (1970) whose data suggest
that in soils having a low As norption cap-
acity, a portion of the As is readily
mobile.
The percentage of sorbed ion extracted
by water can vary by an order of magnitude.
Total amounts extracted, however, were very
low (Table 3), usually <3% of the total
adsorbed. Virtually all of the ion was
released from the top ten percent of the
soil column. Thus, the percent extracted
does not reflect the potential for migra-
tion of the ions because the ions could be
re-adsorbed as they were moved down the
column. The implication is that leaching
with water would not cause serious desorp-
tion of attenuated ions. Of course, these
data give no clue to the effects of redox
potential.
Figure 5 shows that the relative effi-
ciency of the acid versus the water extrac-
tion is not constant throughout the column.
This was true in every case studied. Total
analyses performed on a few of the columns
confirmed that the efficiency of extraction
decreased with column depth. However, the
effectiveness of extraction with water de-
creased much faster than with acid. These
results suggest the presence of more than
one attenuation mechanism and that the
material initially adsorbed by the soil is
the most strongly held.
These data should primarily be viewed
as preliminary and be utilized only as a
point of departure for future research.
Clearly, questions with respect to redox
potential and the effects of extracts with
higher organic matter content have not been
answered. Where time and facilities permit,
an improved method of studying "leaking"
would be by leaching the soil columns suc-
cessively with a waste stream, then with
water or other leachates.
Solution Flux
In the initial leaching work in this
laboratory the migration of Cr was most
susceptible to changes in leaching rate.
Therefore, the effect of three flow rates
of 60 ppm Cr through Kalkaska sand was
examined and the results are shown in
Figure 6. These data were obtained with
the constant flow pump and fraction col-
lector. The most evident manifestation of
the effect of flux is a comparison of the
point at which initial detection occurred.
With both of the faster rates, Cr appeared
in the effluent prior to the leaching of
three pore volumes. With the slower rate,
it was not until 15 pore volumes were
leached that Cr was detected in the efflu-
ent. A similar situation is shown in
Figure 7 with Cr and Fanno clay.
To date three soils have been examined
in this manner for Cr and Cd. The results
have not been as dramatic, as shown in
Figure 8, with 100 ppm Cd and Davidson clay.
Initial detection of Cd was delayed for the
slower rates but the differences are rather
small.
Although these data concerning the
effect of flux are also preliminary, the
potential has been shown that studies of
this type may yield valuable information in
terms of site selection and water manage-
ment of landfills.
The need for other experiments is
suggested by this preliminary work. For
instance, it would be important to know
whether the additional material attenuated
at slow flow rates is as tightly retained.
These measurements may lead to additional
work in terms of measuring reaction rates
and elucidating mechanisms of attenuation.
CREDITS
This research was supported in part
by the U.S. Environmental Protection Agency,
Solid and Hazardous Waste Research Division,
Municipal Environmental Research Laboratory,
Cincinnati, OH, from Contract No.68-03-
0208 and U.S. EPA Grant No. R-803988-01;
University of Arizona Agricultural Experi-
ment Station Paper No. 183.
252
-------
Table 3. THE AMOUNT OF SORBED TRACE ELEMENT EXTRACTED BY DEIONIZED WATER
Ln
U>
Wagram 1 . s .
Ava si. c.l.
Kalkaska s.
Davidson c.
Molokai c.
Chalmers si. c.l.
Nicholson si.c.
Fanno c .
Mohave s . 1 .
Mohaveca c.l.
Anthony s.l.
As
0
3
2.5
0.5
0
nd
2
4.5
0
11.5
0
Cd
9
5
2
1
0.5
nd
1
1
2
0.2
3.5
Cr
0
2
0.5
4
1
nd
10
1
0
6
0
Tra<
Cu
0.5
0.3
0.5
1.5
0.1
nd
0
3
0.5
0.2
3
:e Elemei
Hg
- — 7 -
1.6
0
0
2.2
0
0.5
0
0.5
0
0
9
it
Ni
7
6
18
1
1.1
3
0.2
2
4
0.1
18
Pb
0
0.7
0.3
0
0
nd
0.2
0.2
0.4
0.1
0
Se
1.7
5
9
3
3
nd
0.5
0
3
6
1.8
V
9
0
7.5
0.4
0.7
3.8
1.5
8
0.3
23
28
Zn
8
5
5
3
2
nd
1
1.2
2.5
0.1
2.8
nd = not determined
-------
1.01-
C MAX
IN HCI
456
COLUMN DEPTH (cm)
8
10
Figure 5. Extraction of Ni from Fanno clay.
-------
ho
Ln
Ln
C/CQ
.2 -
0
0
8 12 16 20
PORE VOLUMES
24
28
32
Figure 6. Migration of Cr through Kalkaska sand as related to leaching rate.
-------
NJ
Ln
c/c
0
I.Oi-
.8
.6
.4
.2
0
34 cm/day/ /13cm /day
j I i L
i . i
0
8 10
PORE VOLUMES
i . i
12 14 16 18
Figure 7. Migration of Cr through Fanno clay as related to leaching rate.
-------
ho
Ln
c/c
0
.0
.8
.6
.4
.2
0
6cm/day
I4cm/day
A &24cm/day
0
_L
468
PORE VOLUMES
10
12
Figure 8. Migration of Cd through Davidson clay as related to leaching rate.
-------
REFERENCES
1. Biggar, J.W. and D.R. Nielson. 1960.
Diffusion effects in miscible displace-
ment occurring in saturated and unsatu-
rated porous materials. J. Geophysical
Research 65:2887-2895.
2. Black, C.A. (ed.) 1965. Methods of soil
analysis. Part 2. Chemical and micro-
biological properties. Agronomy Mono-
graph No. 9. Amer. Soc. Agron.
Madison, Wisconsin.
3. Fuller, W.H. and N.E. Korte. 1975,
Attenuation mechanisms of pollutants
through soils. [In Gas and Leachate
from Landfills: Formation, Collection,
and Treatment. Ed. E.J. Genetelli and
R. Landreth] Joint Symp. Cook College,
Rutgers Univ. and U.S. Environ. Protect.
Agency.
4. Fuller, W.H., N.E. Korte, E.E. Niebla,
and B.A. Alesii. 1976. Contribution
of the soil to the migration of certain
common and trace elements. Soil Science
121:76-85.
5. Hodgson, J.F. 1960. Cobalt reactions
with montmorillonite. Soil Sci. Soc.
Amer. Proc. 24. 165-168.
6. Ivanov, D.N. and V.A. Bolshakov. 1969.
Extracting available forms of trace
elements from soils. Khim. Sel. Khoz.
7(3)229-232.
7. Jacobs, L.W., J.K. Syers, and D.R.
Keeney. 1970. Arsenic sorption by soils.
Soil Sci. Soc. Amer. Proc. 34:750-754.
8. Korte, N.E., E.E. Niebla, and W.H.
Fuller. 1976. The use of carbon dioxide
to sample and preserve natural leachates.
J. Water Pollut. Cont. Fed. 40:371-374.
9. Korte, N.E., J. Skopp, W.H. Fuller, E.E.
Niebla, and B.A. Alesii. 1976. Trace
element movement in soils: Influence of
soil physical and chemical properties.
Soil Science (in press).
10. Krauskopf, K.B. 1972. Geochemistry of
micronutrients [In Micronutrients in
agriculture. Eds. J.J. Mortvedt, P.M.
Giordano, W.L. Lindsay]. Soil Sci.
Soc. Amer. Madison, Wisconsin.
11. Lisk, D.J. 1972. Trace metals in soils,
plants, and animals. [In N.C. Brady.
Ed. Advances in Agronomy 24:267-325.]
Academic Press, New York.
12. Nemerov, N.L. 1971. Liquid waste of
industry. Addison-Wesley, Reading,
Massachusetts.
13. Page, A.L. 1974. Fate and effects of
trace elements in sewage sludge when
applied to agricultural lands. Envi-
ronmental Protection Technology Series,
EPA-67012-74-005.
14. Ross, R.D. 1968. Industrial waste
disposal. Chapman-Reinhold, Inc.,
New York.
15. Rouston, R.C. and R.E. Wildung. 1969.
Ultimate disposal of wastes to soil
[In Water. Ed. L.K. Cecil. Chem. Eng.
Prog. Symp. Ser. 64. 97. 19-25].
16. U.S. Environmental Protection Agency.
June 1973. Report to Congress on
hazardous waste disposal.
17. Walsh, L.M., and J.D. Beaton (eds.)
1973. Soil testing and plant analysis.
Soil Sci. Soc. Amer. Madison, Wisconsin.
258
-------
EFFECT OF pH ON REMOVAL OF HEAVY METALS
FROM LEACHATES BY CLAY MINERALS
R. A. Griffin, R. R. Frost, and N. F. Shimp
Illinois State Geological Survey
Natural Resources Building, Urbana, Illinois 6l801
ABSTRACT
The potential usefulness of clay materials as liners for waste disposal sites depends
to a large extent on the pH of the leachate solutions that pass through the landfill and on
ionic competition during the ion adsorption process. Adsorption of the cationic heavy
metals—Pb, Cd, Zn, Cu, and Cr(lll)—was found to increase as the pH increased, while ad-
sorption of the anionic heavy metals—Cr(Vl), As, and Se—decreased as the pH increased.
The presence of leachate reduced the amounts of the cationic heavy metals removed from so-
lution by as much as 85 percent, whereas leachate had a relatively minor effect on the
amounts of the anionic heavy metals removed by the clays. It was concluded that removal of
the heavy-metal cations from solution is primarily a cation exchange-adsorption reaction
that is affected by pH and ionic competition, whereas removal of the heavy-metals anions
is primarily an anion-adsorption reaction in which the monovalent ion is the one being pre-
dominantly adsorbed. Precipitation of the heavy-metal cations in leachate was found to be
an important attenuation mechanism at pH values of 5 and above. No precipitation of the
heavy-metal anions was detected in the pH range 1.0 to 9.0. Adsorption isotherms deter-
mined at various pH values were used to compute how thick a clay liner must be to remove Pb
from solutions of Pb(N03)25 from 0.1 M NaCl, and from two landfill leachates at concentra-
tions ranging between 10 and 1000 ppm Pb and at pH values from 3 to 8. Where pH and ionic
competition are unfavorable, some undesirable environmental consequences of heavy-metal ad-
sorption reactions can occur.
INTRODUCTION
As industry in the United States com-
plies with the Clean Air Act and the Federal
Water Pollution Control Act, it finds itself
obliged to handle and dispose of huge vol-
umes of solid wastes, sludges, and liquid
concentrates of pollutants. With tradition-
al disposal methods outlawed, the quantity
of industrial wastes that must be placed in
landfills is expected to double in the next
10 years. The U.S. Environmental Protection
Agency (l) estimates that about 10 percent
of the nonradioactive industrial wastes will
be classified as hazardous and will there-
fore require special landfill sites and dis-
posal precautions.
While the volumes of industrial wastes
are doubling in the next 10 years, the amount
of land available for industrial waste dis-
posal will be declining. In Illinois, the
Illinois State Geological Survey has for the
past 15 years assisted the regulatory agen-
cies by evaluating the hydrogeologic condi-
tions at proposed or operating waste dispos-
al sites. During the past 8 years the Survey
has appraised conditions relative to pollu-
tion hazard for about 100 sites annually.
Our experience indicates that acceptable dis-
posal sites will be difficult to find in the
future. Their establishment will be approved
only after certain geologic and hydrologic
criteria are met and their operation will be
required to be environmentally acceptable.
259
-------
The relative unavailability of geolog-
ically acceptable sites close to industrial-
ized areas and the rapidly escalating costs
associated with transportation of waste ma-
terials across long distances now make it
economically feasible to consider physical
modifications of sites heretofore geologi-
cally unacceptable that may be ideal in
other respects. Sufficient studies (e.g.,
see 2) have been made to establish that pol-
lutants are attenuated by passage through
earth materials. It has therefore been sug-
gested (2) that a clay liner in the bottom
of otherwise unacceptable sites, such as
gravel pits or old quarries, could make them
acceptable for disposal of municipal and/or
industrial wastes. However, no sound evidence
was available to indicate how thick such a
layer must be or what types of clay minerals
would be best suited for removal of toxic
metals in the presence of the leachates that
would be encountered in the landfill.
This paper reports an overview of re-
sults obtained at the Illinois State Geolog-
ical Survey during an investigation that was
supported in part by U.S. Environmental Pro-
tection Agency contract No. 68-03-0211,
Cincinnati, Ohio. The complete results were
presented in the final report for that con-
tract (3). One purpose of the portion of
the investigation reported here was to de-
termine the capacity of two major types of
clay minerals for removing the potentially
hazardous heavy metals—As, Cd, Cr, Cu, Hg,
Pb, Se, and Zn—from solution. The effect
landfill leachates have on this capacity at
various pH values also was determined. An-
other purpose was to gain insight into the
mechanisms responsible for attenuation of
the various heavy metals and the relative
mobilities of the metals through clay ma-
terials. We also wished to evaluate the
potential usefulness of clay minerals as
liners for waste disposal sites.
EXPERIMENTAL
The research was conducted in the Environ-
mental Geology Laboratory of the Illinois
State Geological Survey. The clays used in
the study were the purified clay minerals
kaolinite and montmorillonite. These par-
ticular clays were chosen because they
closely represent clay minerals commonly
found in soils and because they are obtain-
able in commercially available quantities.
The details of the clay mineralogy, purifi-
cation procedures, and chemical analyses
are available in the final report to EPA (3).
The municipal leachates used in this
study were collected from the Du Page County
landfill and from the Blackwell Forest Pre-
serve landfill, both in northeastern Illi-
nois. Details of the site locations and
sampling procedures also are given in the
final report to EPA (3). The results of
chemical analyses of the leachates are re-
ported in Table 1. For comparison, Table 1
also contains a. summary of the range of
leachate characteristics found for more than
20 other leachates by Garland and Mosher (i)).
The details of the experimental proce-
dures used for the heavy-metal adsorption
studies were given in our final report to
EPA (3). In general, the studies were con-
ducted by placing a known weight of clay in
a flask containing a known volume of the
solution of interest. The pH values of rep-
licate suspensions were adjusted with either
HN03 or NaOH over the pH range 1 to 9. The
suspensions were then shaken in a constant
temperature bath at 25°C, the equilibrium
pH was recorded, the samples were centri-
fuged, and the solutions were analyzed for
their metal concentrations. The difference
between the initial concentration and the
equilibrium concentration was used to com-
pute the amount of metal removed from the
solution at the particular pH by a given
clay mineral. This procedure was carried out
for a range of initial metal ion concentra-
tions that varied between 10 and 1000 ppnu
RESULTS AND DISCUSSION
The results reported here are an over-
view of the detailed final report written
in fulfillment of EPA contract 68-03-0211.
More complete information concerning the
topics presented can be attained by request-
ing a copy of the final report from the
author.
Cationic Heavy-Metal Adsorption
During preliminary experiments on
Cr(lll) adsorption by kaolinite, the removal
curves shown in Figure 1 were obtained.
These curves illustrate the important effect
pH has on the removal of cationic Cr(lll)
species from solutions of Cr(N03)3 and Du
Page leachate. A marked reduction in Cr(lll)
removal due to the presence of leachate is
also shown in Figure 1. This reduction in
removal was observed for all the cationic
heavy metals studied (Cr(lll), Pb, Cu, Zn,
and Cd). The curve labeled "blank" in Fig-
ure 1, representing removal of Cr(lll) from
260
-------
TABLE 1. SUMMARY OF CHEMICAL CHARACTERISTICS
OF LANDFILL LEACHATES
(from Griffin and Shimp (3))
Component
COD
BOD
TOG
Organic acids
Carbonyls
as acetophenone
Carbohydrates
as dextrose
pH
Eh (m.v. )
TS
TDS
TSS
E.G. (mmhos/cm)
Alkalinity ( CaCOj )
Hardness (CaCO )
Total P
Ortho P
N%-N
NO,+N02-N
Al
As
B
Ca
Cl
Na
K
Sulfate
Mn
Me
1 A&
Fe
Cr
Hg
Ni
Si
Zn
Cu
Cd
Pb
Range of all
values from
Garland and
Mosher (4)
(mg/1)
40 to 89,520
9 to 54,610
256 to 28,000
—
—
—
3.7 to 8.5
—
0 to 59,200
0 to 42,276
6 to 2,685
3 to 17
0 to 20,850
0 to 22,800
0 to 154
6 to 85
0 to 1,106
0 to 1,300
—
—
5 to 4,080
34 to 2,800
0 to 7,700
3 to 3,770
1 to 1,826
0 to 1,400
16 to 15,600
0 to 5,500
—
— ~
—
—
o to 1,000
0 to 10
o to 17
0 to 5
Blackwell Forest
Preserve leaohate
data from Hughes ( 2 )
(mg/1)
39,680.
54,610.
—
—
—
—
7.10
-180.
—
19,144.
10.90
3,255-
7,830.
6.
—
—
1.70
2.20
4.31
_
—
1,697.
900.
—
680.
1.66
—
5,500.
0.20
~°~
—
0.05
< 0.05
—
Du Page
leachate used
in sorption
study
(mg/1)
1,362.
—
—
333.
57-6
12.
6.79
-155-
—
5,910.
—
7.20
4,220.
1,100.
< 0.1
—
809-
—
< 0.1
0.11
33.
49.
1,070.
822.
516.
< 0.01
< 0.1
204.
4.40
< 0.1
0.0008
0.3
15.1
o. 03
< 0.1
< 0.01
< 0.1
261
-------
100
90-
80-
i 60-
S
>s
•° 50H
TJ
V
I 40-
30-
20-
10-
Cr (N03)3 solution
Ou Page leachate
—Blank
2.0
—i—
6.0
—i—
8.0
10.0
PH
Figure 1. Removal of Cr(III) from solution by kao-
linite. The curve labeled "Blank" represents a
Cr(NO,), solution without kaolinite.
1 4500-
E
*- 2500
&
2000-
1750-
I50O-
1250-
6OO-
500-
400-
Pb Sorption from Leachote
by Kaolinite
10 ppm Pb
blank
25 30 35 00 45 50 55 60 65
pH
Figure 2. The amount of Pb removed from Du Page
leachate by kaolinite at 25°C plotted as a func-
tion of pH. Initial Pb concentrations (ppm) are
indicated beside each curve.
a solution containing no clay, shows that
precipitation becomes a very important mech-
anism of Cr(lll) removal near pH 5 and
above. The precipitate formed in these ex-
periments was collected and identified by
its color and X-ray diffraction pattern as
hydrated chromic hydroxide.
The results of heavy-metal removal from
25°C solutions of Du Page leachate by kao-
linite and/or montmorillonite were plotted
as a function of pH for Pb in Figure 2, for
Cu, Zn, and Cd in Figure 3, for Cr(Vl) in
Figure h, for Se in Figure 5, and for As(V)
in Figure 6. The data indicate that re-
moval of the heavy-metal cations from land-
fill leachate generally increases with in-
creasing pH values and with increasing con-
centration of the metal ion in solution. As
was true for the Cr(lll) data shown in Fig-
ure 1, the sharp rise in removal in the pH
range 5 to 7 is due to precipitation of var-
ious insoluble hydroxide and carbonate com-
pounds , depending on the pH and the partic-
ular ion in question. In sharp contrast is
the data for the anionic heavy metals
(Cr(Vl), Se, and As), which show a general
decrease in removal as the pH is raised.
In addition, no precipitation of the an-
ionic heavy metals was observed over the pH
range 1 to 9.
When data for heavy-metal removal from
leachate are plotted as a family of curves
of increasing concentration, as shown in
Figures 2 through 6, sorption isotherms may
be constructed from the plot for any desired
pH value within the range given in the plot.
A sorption isotherm can easily be construc-
ted from these plots by placing a vertical
line across the family of curves at the pH
of interest. Figure 2 gives an example at
pH values k, 5, and 6. The amount of metal
ion removed from solution is found on the
graph at the points where the vertical pH
line intersects each curve. The equilib-
rium ion concentrations that correspond to
the chosen pH value are then computed from
the initial concentrations (shown beside
each curve) and the amounts removed from
solution at each concentration. A more
complete description and examples of the
calculation were presented by Griffin and
Shimp (3).
Sorption isotherms were constructed by
this method for several pH values from the
plots given in Figures 2 through 6. A rep-
resentative isotherm computed for Pb from
Figure 2 at pH 5.0 is presented in Figure 7
262
-------
85
65-
"o. 45-
\
fas-
_3
04.5-
64.0-
o
~3.5H
§3.0H
E
£2.5
§2.0
o
< 1.5
1.0
0.5
0.0
MONTMORILLONITE
i . i . i . i . i . i I.!
Cu ,
990
Zn
\ ' i r i
468
PH
Cd
205
Figure i. The amount of Cu, Zn, or Cd removed from
Du Page leachate solutions by montmorillonite at
25°C, plotted as a function of pH. The plots are
labeled with the initial solution concentration
(ppm) of Cu, Zn, or Cd from which each plot was
obtained.
along with sorption isotherms obtained at
pH 5.0 for Pb sorption from Blackwell leach-
ate, pure Pb(N03)2 solutions, and 0.1 M
NaCl solutions containing added Pb(N03)2-
The results indicate that maximum Pb sorp-
tion occurred in pure Pb(W03)2 solutions,
with decreasing sorption in the 0.1 M NaCl
solutions, a further decrease in the Du Page
leachate, and the greatest decrease in
Blackwell leachate.
The sorption isotherms for the two
leachates show a sharp upswing occurring at
equilibrium concentrations of approximately
200 ppm Pb. A sharp upswing in a sorption
isotherm at higher concentrations is gener-
ally viewed as initiation of precipitation
of an insoluble compound. A white precipi-
tate was observed forming in the leachate
solutions and was identified by its X-ray
diffraction pattern as a highly crystalline
PbC03.
The sorption maximums of Pb in pure
Pb(N03)2 solutions, determined from sorption
isotherms such as that shown in Figure 7,
for kaolinite and montmorillonite are, re-
spectively, 15.36 and 79.56 meq Pb++/100 g
clay. These values are comparable to the
cation exchange capacity (CEC) values of
15.1 for kaolinite and 79.5 meq/100 g for
montmorillonite that were determined exper-
imentally. The CEC values are within 2 per-
cent of the Pb sorption maximums determined
from the sorption isotherm—i.e., Pb++ sorp-
tion is merely another method of measuring
the cation exchange capacity of a clay.
This is taken as evidence that cation ex-
change is the principal mechanism of Pb
sorption. More evidence comes from the fact
that, for each of the heavy-metal cations
studied, montmorillonite adsorbed five times
more metal ion than kaolinite. This five-
fold increase is the ratio of their respec-
tive CEC values.
Other evidence in support of a cation
exchange mechanism is the reduction in Pb
sorption from solutions containing 0.1 M NaCl
and from the two leachates (Figure 7). The
decrease in Pb sorption is attributed to in-
creasing competition for cation exchange
sites by Na+ in the 0.1 M NaCl solutions and
to an increase in the divalent cation compe-
tition in the two leachates. The Blackwell
leachate has a much higher total salt con-
tent than the Du Page leachate, and the high
concentrations of competing ions could ac-
count for the greatly reduced Pb sorption in
landfill leachate compared to the sorption
in pure Pb(N03)2 solutions.
The results of the above studies with
Pb, similar results for Cr(lll), Cu, Zn, and
o 0.000-
8.0
Figure 1J-. Chromium (VI) adsorption-pH curves for
kaolinite at 25°C. Initial Cr(Vl) concentrations
(ppm) are indicated beside each curve.
263
-------
Cd, and the evidence from other supporting
studies (3), have led to the conclusion that
the removal of the heavy-metal cations from
strongly acid solutions by clay minerals is
primarily an exchange-adsorption reaction
that is affected by ionic competition. As
the pH is raised, adsorption is increased
due to reduced competition from H+ and for-
mation of a series of hydroxyl complex ions
of lower valence. Finally, initiation of
precipitation occurs in the pH range 5 to 7
and precipitation becomes the major removal
mechanism in the neutral and alkaline pH
range. All of the heavy-metal cations stud-
ied followed this pattern. However, the
amounts removed and the pH at which precipi-
tation was initiated varied with the indi-
vidual element (Figures 1, 2, and 3).
Anionic Heavy-Metal Adsorption
The data for Cr(Vl) removal from solu-
tions of K^CrOLj and Du Page leachate (Figure
U) are in sharp contrast to the data for the
cationic heavy metals presented above. The
Montmorillonite
Figure 5. The amount of Se(IV) removed from Du
Page leaohate solutions by kaolinite and raont-
morillonite at 25°C plotted as a function of pH.
Labels are the initial solution concentration of
Se(IV) in ppm.
Montmorillonite
•
IZ8
Figure 6. The amount of As(V) removed from Du Page
leachate solutions by kaolinite and montmoril-
lonite at 25°C plotted as a function of pH.
Labels are the initial solution concentration of
As(V) in ppm.
0 25 30 100
Equilibrium Pb concentration (ppm)
Figure 7. The amount of Pb sorbed per gram of
kaolinite at pH 5.0 and 25°C plotted as a func-
tion of the equilibrium Pb concentration.
264
-------
most striking difference is that sorption is
reduced as the pH is increased. An important
point to note is that sorption actually goes
to zero at approximately pH 8.U. A second
major difference is that sorption is greater
from leachate than from pure K^CrOif solu-
tions. Other major differences, not obvious
from the figure, are the absence of precipi-
tation in the pH range 1 to 9 and the small
amounts removed from solution compared to
the results for cationic heavy metals. The
differences make it clear that the sorption
and removal mechanism for the anionic heavy
metals (Cr(Vl), Se, and As) is quite unlike
the mechanism for the cationic heavy metals.
Diagrams showing the distribution of
Cr(Vl) species in solution as a function of
pH were constructed to aid in interpretation
of the data. The principal species in solu-
tion throughout the pH range of maximum ad-
sorption was the HCrOTJ ion. The diagram
showed that the fraction of HCrOTJ ions in
solution begins at pH 5 to decrease rapidly,
reaching zero at pH 8.4. The principal spe-
cies present in solution at pH values above
8.4 is Cr042~. Below pH 2, the fraction of
HCrO'iJ ions decreases rapidly as the fraction
of I^CrOi,. species increases.
The behavior of the Cr(Vl) adsorption-
pH curves in Figure 4 implies that the HCrOIJ
ion is the principal ion being adsorbed by
the clay minerals. Conversely, the lack of
adsorption at pH values above 8.5 indicates
that the CrO^2" ion is completely unadsorbed
by the clay. Apparently the divalent anion
species is repelled by the net negative
charge on the clay surface.
For both clay minerals, more Cr(Vl) was
adsorbed from Du Page leachate solutions
than from pure K^CrO^ solutions throughout
the pH range 3 to 7. Evidently, anions
(e.g., Cl~ and HCO^) in the leachate do not
compete favorably with HCrOIJ ions, or ad-
sorption would have decreased. The higher
adsorption in leachate may result from for-
mation of organic or inorganic polynuclear
complexes in the leachate solution that can
be adsorbed by the clay.
Similar results have been obtained for
the clay mineral adsorption of Se(lV) and
As(v) species from leachate (Figures 5 and
6). Although the data are not as complete
as those for Cr(Vl) adsorption, the Se data
shown in Figure 5 apparently converge on
zero adsorption at approximately pH 10.
As was true for Cr(Vl), this result corres-
ponds to the point in the Se(lV) species
distribution at which the monovalent HSeOI
ion goes to zero and the Se032~ ion emer-
ges. At pH values below 3, H2Se03 is the
principal species in solution, and the
HSe03 ion decreases rapidly. This pattern
corresponds to the sharp decrease in Se ad-
sorption at pH values less than 3 shown in
Figure 5.
Results similar to those for Cr(Vl)
and Se(lV) species are shown for As(V) spe-
cies in Figure 6. It is noteworthy that
the amount of As(V) species removed from
solution reaches a maximum at about pH 5.
Comparison of the distribution of As(v)
species in solution as a function of pH re-
veals that the As(V) removal curves follow
the monovalent I^AsOi; species distribution
curve almost exactly. It was therefore con-
cluded that the monovalent H^AsO^ ion is
the principal species being adsorbed by the
clay minerals, a conclusion similar to those
reached for Cr(Vl) and Se(lV).
The results of this study indicate
that pH has a pronounced effect on the
amounts of Cr(Vl), Se(lV), and As(v) ad-
sorbed from solutions by clay minerals. It
was concluded that the principal adsorption
mechanism is anion exchange and the species
distribution diagrams led us to believe that
the adsorption was due principally to the
monovalent species of each element studied,
which led to the strong pH dependency of
the adsorption process. The precise mech-
anism for anion adsorption by clay minerals
is not known but we conclude, as others
have, that anion exchange plays an impor-
tant role in the adsorption process.
A comparison of the relative amounts
of heavy metals removed at pH 5.0 from 100
ppm equilibrium concentration solutions of
the metals studied, both cationic and ani-
onic, is presented in Table 2. The table
indicated that the cationic heavy metals
are generally adsorbed to a greater degree
than the anionic forms. However, this rank-
ing is somewhat pH dependent since the
greatest anion adsorption occurs in acid
solutions and the greatest cation adsorption
in alkaline solutions. Thus, the ranking
changes somewhat at different pH values.
A significant point shown in Table 2
is the importance of the valence state of
an element to the amount of that element
265
-------
TABLE 2. REMOVAL OF HEAVY METALS FROM
SOLUTIONS BY KAOLINITE AT pH 5.0
Amount removed at 100 ppm
equilibrium concentration
(micromoles/g)
Element
Cr (III)
Cu
Ft
As (V)
Zn
As (III)
Cd
Cr (VI)
Se
Pure"
solutions
769*
55-1
4-2.3
t
33.6
f
26.7
0.62
t
Du Page
leachate
576*
15-7
12.1
5-3
3.8
2.0
1.9
1.9
1.9
* Precipitation contributes to removal
at pH 5.0.
t Removals from 4-0 ppm solutions were
approximately the same as removals
from leachate.
t Removals from 4-0 ppm solutions were
30 percent greater than from re-
movals from leachate.
removed from solution by clay minerals.
Cr(lll) species are removed to a much great-
er extent than Cr(Vl) species. Studies
showed that the clay minerals removed 30 to
300 times more Cr(lll) from solution than
Cr(Vl). The table also shows the more ex-
tensive removal of As(v) than As(ill).
These results indicate that safer disposal
of certain elements may be achieved by con-
version of the element, prior to deposition
at the landfill or disposal site, to the
form that would be most strongly attenuated.
Application of Data to Site Design
An example of how data from the study
can be used is its application to the ques-
tion posed at the beginning of the paper—
how thick a proposed clay liner must be to
remove a specific heavy metal from a land-
fill leachate or industrial waste stream.
Lead is used here as an example.
From a family of adsorption-pH curves,
such as those in Figure 2, adsorption iso-
therms for a given pH solution can be con-
structed—for example, the Pb isotherms
constructed at pH 5.0 shown in Figure 7. The
amount of Pb that will be removed from a pH
5.0 solution of given concentration by one
gram of kaolinite clay can be read directly
from the graph or computed by fitting an
equation to the data. Therefore, if the
amount of Pb and the pH of the solution are
known, the thickness of clay necessary to
remove it from solution can easily be cal-
culated. Conversely, if the thickness of
clay is given, then the volume at which the
Pb will saturate the adsorption capacity
and break through the liner also can be
easily computed. However, this approach as-
sumes equilibrium conditions exist and also
that dispersion and diffusion are negligible.
Such ideal conditions seldom exist during
dynamic flow through a porous media.
To determine the validity of using ad-
sorption isotherms to predict the thickness
of a clay liner, leaching experiments were
carried out in laboratory columns. A col-
umn containing quartz sand mixed with a
known weight of kaolinite was leached with
pH 5.0 Du Page leachate containing 100 ppm Pb
added as Pb(W03)2. Analysis of the column
effluent for Cl~ and Pb++ were carried out
on 5 ml effluent fractions collected with
an automatic fraction collector. The volume
at which Pb breakthrough would occur was
computed from the data plotted in Figure T.
The results are shown in Figure 8. Chloride
is assumed to be a non-interacting ion, and
its breakthrough pattern gives a relative
idea of the dispersion component of the col-
umn. A slow flow rate of approximately 0.^-
ml/min was used so that the assumption of
equilibrium conditions was closely approxi-
mated. The results shown in Figure 8 indi-
cate that the actual Pb breakthrough closely
approximated the predicted Pb breakthrough
curve. Comparison of the Pb and Cl data
points indicates that deviations between
the "actual" and "predicted" curves were
largely caused by dispersion.
A second column containing a known
weight of clay in a clay-sand mixture was
leached with a fixed volume of solution.
The solution contained 100 ppm Pb in a 0.1
M Nad matrix. The solution was adjusted to
pH 5.0 and a known volume added to the top
of the column. The depth of Pb penetration
in the column was predicted by using the
data for Pb adsorption from NaCl solutions
given in Figure T. After the column had
drained freely, the contents were cut into
sections and analyzed for their Pb content.
The results are shown in Figure 9. The
266
-------
1 r\
I.U
0.9-
0.8-
0.7-
0.6-
o
•£0.5-
0.4-
03-
02-
0.1-
f\f\
\J\J
(
p.x*r*x
' /
Predicted
Pb breakthrough
\
Cl breakthrough
*
]
1 1
1 |
1 1
1 1
| 1
1 I
y VV V . V
31234
A
/ \
Actual distribution
of Pb
.
i i i i
5678
Volume/void volume
Figure 8. Predicted and actual breakthrough curves
for a column leached with Du Page leanhate with
100 ppm added Pb and containing 2 percent kao-
linite mixed with sand.
predicted depth, of Pb migration closely ap-
proximated the actual distribution of Pb in
the column.
A better prediction could undoubtedly
be achieved if the effect of dispersion
were included. However, the simplistic ap-
proach used here may give sufficiently ac-
curate estimates of the necessary clay depth
for many purposes without the expense of
computer-implemented calculations. The re-
sults of computations of the thickness of
clay liners necessary for removal of Pb
from solutions of various compositions are
given in Table 3.
Table 3 shows how thick a square meter
of a 30 percent clay liner, packed to a bulk
density of 1.60 g/cc, need be to remove all
the Pb from 762 liters (201 gal) of solu-
tion. This particular volume is the amount
generated from a typical sanitary landfill
containing municipal solid waste placed 3
meters (10 feet) deep and having an annual
net infiltration of 2$U mm (10 inches) (5).
The thicknesses of the clay liner given in
the table, therefore, effect total removal
of Pb for one gear by a square meter of lin-
er at the given concentrations of Pb and pH
values. They are, of course, the minimum
thicknesses possible, since they represent
an idealized situation. The actual thick-
ness necessary in a field application must
be somewhat greater to allow for nonequilib-
rium conditions, physical dispersion, dif-
fusion, and the normal engineering safety
factors.
The information in Table 3 indicates
that only relatively thin layers of clay,
especially montmorillonite, are necessary
for removal of Pb unless the pH values are
very acid and the Pb concentrations are
high. The high sorption capacity of clay
minerals and the reversible nature of ex-
change adsorption reactions have important
environmental consequences. Soils and
Pb odsorbed (%)
0 10 20 30 40 50 60 70 80 90 100
o-
2-
4-
6-
8-
10-
12-
14-
16-
? 18-
o
e 20-
a.
* 00
o 22-
24-
26-
28-
30-
32-
34-
36-
38-
/in-
]
I
1
Predicted depth of
»
,
!)
Figure 9. Predicted and actual distribution of Pb
with depth in a column leached with 0.1 M NaCl
with 100 ppm Pb added and containing 2 percent
kaolinite mixed with sand.
267
-------
TABLE 3. THICKNESS (cm) OF A SQUARE METER OF A 30% CLAY LINER
NEEDED TO REMOVE Pb FROM 762 LITERS (201 GALLONS) OF
SOLUTION PER YEAR
10 ppm Pb
at pH
3 5 8
100 ppm Pb
at pH
3 5 8
1000 ppm Pb
at pH
3 5 8
KAOLINITE
Pb(N03)2
0.1 M NaCl
Du Page
Blaokwell
—
—
15-9
19.8
< 1 —
< 1 —
2.1 *
1.0 *
5.3
—
28.9
19.6
1.8 < 1
2.3 —
6.1 *
11.3 *
—
—
79-1
264.6
10.0
15.5
*
#
—
—
*
*
MONTMORILLONITE
Pb(N03)2
Du Page
—
9-9
< 1 —
1.8 *
—
13.2
< 1 —
3.7 *
—
18.0
1.93
#
—
*
* Precipitation as PbCOj.
surface waters may change in ionic composi-
tion or pH as environmental conditions
change. A sudden decrease in pH may release
large amounts of potentially toxic Pb into
the aqueous phase, especially in places
where PbC03 has accumulated. Cations, es-
pecially di- and trl-valent, compete with
Pb and may exchange with it, thus allowing
Pb to come into solution. These multiple
interactions must be considered when a dis-
posal site is designed and th.e environmental
impact of Pb and other heavy metals assessed.
REFERENCES
1. U.S. Environmental Protection Agency.
Report to Congress on hazardous waste
disposal. U.S. EPA publication SW-115,
Washington, D.C. 20^60. June 30, 1973.
2. Hughes, G. M., R. A. Landon, and R. M.
Farvolden. Hydrogeology of solid waste
disposal sites in northeastern Illinois.
U.S. EPA report SW-12d, 1971.
3. Griffin, R. A., and N. F. Shimp. Attenu-
ation of pollutants in municipal land-
fill-leachate by clay minerals. Final
report for contract 68-03-0211, U.S.
EPA, Cincinnati, Ohio 1+5268, in prepara-
tion.
k. Garland, G. A., and D. C. Mosher. Leach-
ate effects from improper land disposal.
Waste Age 6:1*2-48, 1975.
5. U.S. Environmental Protection Agency.
Summary report: Gas and leachate from
land disposal of municipal solid waste.
U.S. EPA, Cincinnati, Ohio 1+5268, 197U.
268
-------
DEVELOPMENT OF A COMPUTER SIMULATION MODEL FOR
PREDICTING TRACE ELEMENT ATTENUATION IN SOILSl
Joe Skopp^
Department of Soils, Water, and Engineering
The University of Arizona
Tucson, Arizona 85721
ABSTRACT
Columns of differing soils were leached with various trace metals so as to obtain
breakthrough curves. A nonequilibrium model presented by Lapidus and Amundson was
applied to the data obtained from these short term laboratory soil columns. The data
was used to obtain the dispersion coefficient and first order rate constants assumed
in the model. This was done via a nonlinear parameter estimation procedure using a
standard least squares gradient technique. The parameters were then used to obtain
"time of travel" curves which were generated for long times. Such curves can easily
be used in formulating design criteria for the management of trace metal migration in
soils.
Original paper in the final draft of Report submitted to Solid and Hazardous Waste
Research Division, Municipal Environmental Research Laboratory, U.S. Environmental
Protection Agency, for Contract No. 68-03-0208, March 1976, Cincinnati, OH 45268,
(In press).
o
Current address, Soil Science, University of Wisconsin, Madison.
269
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1 . REPORT NO
EPA-600/9-76-015
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
RESIDUAL MANAGEMENT BY LAND DISPOSAL
PROCEEDINGS OF THE HAZARDOUS WASTE RESEARCH SYMPOSIUM
5. REPORT DATE
July 1976 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Wallace H. Fuller, Editor
8. PERFORMING ORGANIZATION REPORT NO,
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Dept. of Soils, Water and Engineering
University of Arizona
Tucson, Arizona 85721
10. PROGRAM ELEMENT NO.
1DC618(SOS 3 Task 04)
11. eeNTftACT/GRANT NO.
804330
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Oln'o 45268
13. TYPE OF REPORT AND PERIOD COVERED
Symposium Feb. 2-4, 1975
14. SPONSORING AGENCY CODE
EPA-ORD
15. SUPPLEMENTARY NOTES
Robert E. Landreth, Project Officer 513/684-7871
, research'symposium was held to exchange recent information on land disposal
of municipal and hazardous wastes. Papers were presented and compiled into a report on
the following topics: (1 )Case studies of actual and potential environmental impact
from land disposal of hazardous wastes; (2) Technology of preventing adverse environ-
mental impact; (3) Selection of disposal sites to minimize adverse impact; (4) Ameli-
orating damages at existing disposal sites and suggested modification of future sites
and wastestreams; (5) Identification of pollution potential of selected industrial
solid wastes, and (6) Special disposal problems.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS C. COS AT I Field/Group
Leaching, Collection, Hazardous
materials, Disposal, Soils, Ground
water, Pollution, Permeability,
Waste treatment, Linings
Solid waste management,
Hazardous waste,
Leachate, Toxic
13B
13. DISTRIBUTION STATEMEN1
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report)
UNCLASSIFIED
21. NO. OF PAGES
280
20. SECURITY CLASS (Thispagej
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
270
• U. S. GOVERNMENT PRINTING OFFICE:'1976-657-&95/5it61i Reg ion No. 5-11
-------
(b v> -~
O- sb -s
O .3 -<
5 CD' o
75
o §
••!
Q) ^1
3*
I:.
3 <*
3 I
M
* 3
g> a
§•
O
O-
§
1- 5t
II
~k 3
52
I 3
a
a
i -
» 2
s °>
^ Q>
3 «
Vl *
to S
1 ^
(b
§
3^
n
|
o
! P
f m
gb
u r-
x o
»-» G> .
J>
co
CD i
i-i p- ,
o m ?
"C O
CO
o
t—I
z
z
I
z
m
D
C
>
r
O
•o
T]
O
JO
H
c
z
H
<
m
Z
•o
f-
0
.<
Tn
TJ
."*
D
m
Z
(—
H
<
•n
O
X
-Q
D
<
>
-\
m
C
y>
m
(/)
0)
o
0
O
Tl
-n
O
>
f-
CD
C
CO
z
m
0)
0)
o
3
o
B'
^j
0)
O
:r
o'
A
en
N)
O>
00
— I
0
o
•3-
•3
o'
OJ
~
— *1
o
-^
3
03
»-*•
6'
C/5
r-f
0)
^
—4^
O
o
CD
O
— «*
33
CD
GO
CD
0)
^
O
IT
03
D
Q.
Develoi
o
3
CD
•^
~j
r-+-
m
z
<
J3
O
Z
S
m
z
H
[—
"D
U
0
m
0
H
O
>
o
m
z
o
0)
o
o
JT
0)
TJ
(D
O
Tl
O
C
O
m
Z
<
I 3
I H
1 s
m -i m
r z
T) O
-n _
o S
H m
m (/)
o.-.
m
Z
o ,.
<
------- |