EPA-600/2-78-024
March 1978
Environmental Protection Technology Series
SORBENTS
FOR FLUORIDE, METAL FINISHING,
AND PETROLEUM SLUDGE LEACHATE
CONTAMINANT CONTROL
Municipal Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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EPA-600/2-78-024
March 1978
SORBENTS FOR FLUORIDE, METAL FINISHING, AND PETROLEUM SLUDGE
LEACHATE CONTAMINANT CONTROL
by
Paul C. Chan
Robert Dresnack
John W. Liskowitz
Angelo Perna
Richard Trattner
New Jersey Institute of Technology
Newark, New Jersey 07102
Grant No. R803717
Project Officer
Fred Ellerbusch
Industrial Pollution Control Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Municipal Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publica-
tion. 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.
ii
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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 complex-
ity 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 solution,
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 preventing, treating, and managing waste-
water and solid and hazardous waste pollutant discharges from municipal and
community sources, for preserving and treating public drinking water supplies,
and for minimizing the adverse economic, social, health, and aesthetic effects
of pollution. This publication is one of the products of that research, a
most vital communication link between the researcher and the user community.
This report deals with the investigation of leachate contaminant control
using sorbents. Ashes, clays, and refined materials were tested to determine
their capacity to remove leachate contaminants produced from three industrial
sludges—calcium fluoride, metal hydroxide, and petroleum. The report will
provide data to government and industry alike contemplating residue leachate
control from industrial sludge impoundment via sorbent contact.
Francis T. Mayo
Director
Municipal Environmental
Research Laboratory
iii
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ABSTRACT
A laboratory evaluation of bottom ash, acidic and basic fly ashes, vermi-
culite, illite, activated carbon, kaolinite, natural zeolite, activated alumi-
na, and cullite for the removal of contaminants in the leachate and liquid
portion of three industrial sludges (calcium fluoride, metal finishing, and
petroleum) is presented. Batch and lysimeter studies were carried out to
evaluate the static and dynamic sorbent capacity for the constituents present
in the leachate. Also, permeability exhibited by these sorbents when con-
tacted with the above industrial sludge leachate was studied. The pH, con-
ductivity, chemical oxygen demand (COD), total organic carbon (TOC), cationic
and anionic species in the leachate before and after contact with the sorbent
materials, and the coefficient of permeability were determined.
The analysis of the leachate showed that considerable variations exist in
composition and concentration of constituents in the leachate prepared from
the same industrial sludge, which was collected over the period of this inves-
tigation. The results of the batch and lysimeter studies reveal that no
single sorbent, but combinations of two, three, or four sorbents, can be used
to reduce the concentration of the constituents found in the leachate of a
specific sludge. These are acidic and basic fly ashes, kaolinite, and illite
for the calcium fluoride sludge leachate; verrniculite, kaolinite, and illite
for the metal finishing sludge leachate; basic fly ash, vermiculite, and kao-
linite for the petroleum sludge leachate. The combination of the more expen-
sive activated carbon and activated alumina was found to be the more effective
combination for treating the calcium fluoride sludge leachate but less effec-
tive than the ash and clay combinations in treating the metal finishing sludge
leachate and petroleum sludge leachate. The selection of a sorbent combina-
tion is sludge leachate specific. In some cases, the most effective sorbents
for the remoyal of the same contaminant in the leachate from different sludges
are not the same. Also, significantly greater sorbent capacities for the
measured contaminants in the leachates are achieved by the sorbents under
dynamic conditions than are achieved under static conditions. In addition,
change in pH of the sorbent from acidic to alkaline, such as resulted when
alkaline fluoride sludge leachate and metal finishing sludge leachate were
passed through the acidic fly ash and illite, was found to favor the removal
of cations.
This report was submitted in fulfillment of grant No. R803717 by New
Jersey Institute of Technology under partial sponsorship of the U.S. Environ-
mental Protection Agency. This report covers the initial laboratory studies
carried out to identify the most promising sorbents that may be used to
significantly reduce the concentration of measurable contaminant in calcium
fluoride sludge leachate, metal finishing sludge leachate, and petroleum
sludge leachate. The study covers the period from June 1975 to May 1977.
iv
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CONTENTS
Foreword in
Abstract iv
Figures yi
Tables viii
Acknowledgment ix
1. Introduction 1
2. Conclusions 4
3. Recommendations 7
4. Materials Description 9
Sorbents 9
Sludge sources 11
5. Experimental Procedures 13
Preparation of sorbent materials 13
Preparation of background leachates from sorbents ... 13
Preparation of sludge leachates 13
Static studies 14
Dynamic studies 14
Analytical procedures 16
Permeability studies 17
Grain size determination 17
6. Results and Discussion 20
Results of static studies 20
Results of lysimeter studies 36
References 82
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FIGURES
Number Page
1 Laboratory arrangement of lysimeters 15
2 Grain-size distribution of sorbents 19
3 Lysimeter studies of pH in calcium fluoride sludge leachate 38
4 Lysimeter studies of calcium ion in> calcium fluoride sludge
1 eachate 40
5 Lysimeter studies of copper ion in calcium fluoride sludge
leachate 42
6 Lysimeter studies of magnesium ion in calcium fluoride
sludge leachate 44
7 Lysimeter studies of fluoride ion in calcium fluoride
sludge leachate 45
8 Lysimeter studies of COD in calcium fluoride sludge leachate.... 47
9 Lysimeter studies of TOC in calcium fluoride sludge leachate 48
10 Permeability studies of sorbent materials with calcium
f 1 uoride si udge 1 eachate 51
11 Lysimeter studies of pH in metal finishing sludge leachate 52
12 Lysimeter studies of calcium ion in metal finishing sludge
1 eachate 55
13 Lysimeter studies of copper ion in metal finishing sludge
1 eachate 57
14 Lysimeter studies of magnesium ion in metal finishing
sludge leachate 58
15 Lysimeter studies of nickel ion in metal finishing sludge
leachate 60
16 Lysimeter studies of fluoride ion in metal finishing sludge
1 eachate 61
VI
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Number Page
17 Lysimeter studies of COD in metal finishing sludge leachate 62
18 Lysimeter studies of TOC in metal finishing sludge leachate 63
19 Permeability studies of activated carbon 64
20 Permeability studies of sorbent materials with metal
finishing sludge leachate 66
21 Lysimeter studies of pH in petroleum sludge leachate 68
22 Lysimeter studies of calcium ion in petroleum sludge
1 eachate 69
23 Lysimeter studies of copper ion in petroleum sludge leachate 71
24 Lysimeter studies of magnesium ion in petroleum sludge
1 eachate 73
25 Lysimeter studies of zinc ion in petroleum sludge leachate 74
26 Lysimeter studies of fluoride ion in petroleum sludge
1 eachate 75
27 Lysimeter studies of cyanide ion in petroleum sludge
1 eachate 77
28 Lysimeter studies of COD in petroleum sludge leachate 78
29 Lysimeter studies of TOC in petroleum sludge leachate 79
30 Permeability studies of sorbent materials with petroleum
sludge leachate 80
vii
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TABLES
Number Page
1 Static Study Results of Calcium Fluoride Sludge Leachate #1 22
2 Static Study Results of Calcium Fluoride Sludge Leachate #2 23
3 Static Study Results of Calcium Fluoride Sludge Leachate #3 24
4 Comparisons of Sorbent Capacities in Static and Lysimeter
Tests (Calcium Fluoride Sludge Leachate) 25
5 Static Study Results of Metal Finishing Sludge Leachate #1 28
6 Static Study Results of Metal Finishing Sludge Leachate #2 29
7 Static Study Results of Metal Finishing Sludge Leachate #3 30
8 Comparisons of Sorbent Capacities in Static and Lysimeter Tests
(Metal Finishing Sludge Leachate) 31
9 Static Study Results of Tank Bottom Petroleum Sludge Leachate... 33
10 Static Study Results for API Separator Petroleum Sludge
Leachate 34
11 Comparisons of Sorbent Capacities in Static and
Lysimeter Tests (Petroleum SIudge Leachate) 35
12 Permeability Characteristics of Sorbent Materials 54
vi i i
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ACKNOWLEDGMENTS
The authors are deeply indebted to Fred Ellerbusch, Sanitary Engineer,
Industrial Environmental Research Laboratory, U.S. Environmental Protection
Agency, Cincinnati, Ohio, for his guidance in this project.
We would further like to express our thanks to the following companies
for their cooperation in supplying the sorbents used in this study: Georgia
Kaolin Company, Elizabeth, New Jersey (kaolinite); Double Eagle Petroleum
and Mining Company, Casper, Wyoming (zeolite); Culligan International Company,
Northbrook, Illinois (cullite); Public Service Electric & Gas Company, Hudson
Generating Station, Jersey City, New Jersey (fly ash and bottom ash); Alcoa,
Bauxite, Arkansas (activated alumina). In addition, we thank the Exxon Corpor-
ation, Linden, New Jersey, and Hoffman-LaRoche Corporation, Nutley, New Jersey,
for their assistance with the initial analysis of the leachates.
We appreciate the efforts of Mung Shium Sheih, Richard Trayer, and Tak
Hoi Lee, graduate students in the Institute, for their efforts in conducting
the various experiments. In particular, we thank Mr. Sheih for his contribu-
tions in various phases of this project.
The authors are especially appreciative of Irene Mitchell and Diana Mul-
drow for their patience and skillful typing of the entire manuscript.
IX
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SECTION 1
INTRODUCTION
As a result of the establishment under the Federal Water Pollution Con-
trol Act of 1972 of a nonpollutant 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 waste streams. Some progress has been made in the development of clos-
ed-loop type waste treatment. However, this technology is not expected to
significantly reduce the sludge volume in the near future. Currently, the
most often used sludge disposal technique for industrial sludges is the "sani-
tary" landfill. Moreover, the disposal of industrial sludge in landfills can
lead to contamination of ground and surface waters through runoff and percola-
tion. Present-day sanitary landfills cannot be considered a panacea for the
ultimate disposal of hazardous wastes.
At present, means to accurately predict the leaching potential, direction
and rate of flow of the leachate through the soil surrounding the landfill
site is lacking. These problems could be overcome by isolating the landfill
site from its immediate soil surroundings. By lining the base and sides of
the landfill with compacted soil of low impermeablity, horizontal groundwater
movement of the leachate is prevented. Polyvinyl chloride and butyl rubber
liners have also been used for this purpose. This liner creates a "tub with-
out a drain" unless the rainwater that percolates down through the landfill is
provided a route of escape. This could be accomplished by using gravity out-
lets, such as drainage tiles, or perforated corrugated metal pipe, installed
in the lowest portion or along the base of the landfill to remove and collect
the leachate. Further treatment of the collected leachate would be required
to reduce the pollutants to acceptable discharge levels, assuming that treat-
ment technology is available. In any event, additional construction and
operating costs would be required.
It is the intent of this study to establish a design approach for the
removal of leachate components at the landfill site using relatively inexpen-
sive natural clays and other sorbents such as fly ash and bottom ash.
This report deals with the results of a laboratory study which has been
conducted to evaluate the effectiveness for contaminent removal of ten natural
and synthetic sorbent materials on the liquid portion and leachate generated
from three different industrial sludges.
The sorbent materials that were used were fly ash, bottom ash, illite,
kaolinite, vermiculite, natural zeolite, Ottawa sand, cullite, activated car-
bon and activated alumina. Activated carbon and activated alumina were
1
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included in this study even though they are far more expensive than the other
sorbents because they are generally known to be effective sorbents for the
removal of organics, cations and anions from waste streams. Their use may be
warranted if the above inexpensive sorbents are not effective in removing a
specific component from the leachate. Cullite, which is a synthetic zeolite,
was examined because it is widely used in water softening applications.
Ottawa sand is included because it is mixed with some of the naturally occur-
ring sorbents to improve their permeabilities. It was found in our prelimi-
nary work prior to this study to be relatively inert to the experiments.
Studies exploring possible application of fly ash in this area of waste-
water treatment have been investigated by a number of investigators. Deb
et al. (1) and Nelson and Guarino (2} reported the use of fly ash for the re-
moval of COD from wastewater. They concluded that the unwashed fly ash added
appreciable COD but not BOD to the solution. Ballance et al. (3) investigated
fly ash as a coagulant aid in water treatment, reporting that fly ash has cer-
tain properties which enhanced chemical coagulation and settling of turbid
water.
Soil chemists have shown an interest in ion removal by clay soils for
many years. For a complete discussion of chemical reaction and clay mineral
structures, the reader is referred to standard works—for instance, Grim
(4) and Brown (5). Investigations have dealt, however, in the main, with
selected ions, e.g., phosphorous adsorption by Fried and Shapiro (6), Olson
and Watanable (7), Ellis and Erickson (8), zinc adsorption by Tiller (9), and
Sharpless, Wallihan, and Peterson (10). For ion removal, Bittell and Miller
(11) investigated the removal of lead, cadmium, and calcium by montmorillonite,
illite, and kaolinite. They found that the cations exhibited consistent pre-
ferential sorption characteristics for the three clays. Calcium and cadmium
competed evenly, while lead showed favorable sorption over calcium by a factor
of 2 to 3. Recently, several investigators have examined the effectiveness of
kaolinite, illite, montmorillonite, and soil mixtures in removing pollutants
such as heavy metals and organic compounds. Fuller et al. (12) examined
eleven soil mixtures, ranging from sandy loam to clay mixtures, mixing with
limestone and hydrated Fe2$04, for developing a sanitary landfill liner. Pre-
liminary results indicated both limestone and dehydrated FepS04 nad a signifi-
cant retarding influence on migration rate of the cations and anions studied.
Another investigation by Griffin et al. (13) examined the effect of pH on
removal of heavy metals by kaolinite and montmorillonite. They concluded
that both cationic and anionic adsorption on these two clays were pH depen-
dent. Ihe adsorption of the cations was increased as the pH was raised.
The above investigations, however, examined the effectiveness of clays
for removing specific contaminant(s) from leachates that were synthesized or
modified in the laboratory. Early laboratory work (14) on the chemical and
physical reactions of radioactive liquid waste with soils indicated that the
removal of radioisotopes from solutions by exchange with the soil is influ-
enced by the concentration of other cations in solutions as well as the total
salt concentration. These results indicate that the composition of a leachate
could influence the removal of a specific contaminant using a given sorbent.
Therefore, our studies were carried out using leachates prepared directly from
the industrial sludges without modification to achieve a more realistic eval-
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uation of the sorbents for contaminant removal.
The sludges chosen for this study were a calcium fluoride sludge (of the
type generated by the electronic and aircraft industries), a metal finishing
sludge, and a petroleum sludge. These sludges were selected because their
annual production is of a significant magnitude to present disposal problems.
Also, the leachate from these sludges contains a cross-section of hazardous
organic constituents, heavy metal hydroxides, anions such as cyanide, and sub-
stantial amounts of fairly soluble toxic salts such as calcium fluoride.
Analysis of the leachate generated from these sludges involved the determina-
tion of pH, conductivity, chemical oxygen demand (COD), total organic carbon
(TOC), anionic species, and cationic species, before and after contact with
sorbent materials.
Static studies were initially conducted to evaluate the capacity of these
sorbent materials, using leachate with the maximum concentrations of contami-
nants that could be obtained from the sludge. These studies were carried out
to define the most promising sorbent materials for removal of the constituents
in the sludge leachate. The static studies were then followed by lysimeter
studies using the most promising sorbent materials to obtain information re-
garding the dynamic capacity and permeability characteristics of these mate-
rials.
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SECTION 2
CONCLUSIONS
A number of sorbents have been identified as exhibiting a removal capa-
city for leachate constituents under flowing conditions from the three types
of sludges investigated. No single sorbent material was found to be effective
in removing all the objectionable ions from the leachates studied. Two,
three, or four different sorbents could be collectively combined to reduce
sludge leachate contaminant levels. The combination of acidic fly ash, kaolinite,
illite and basic fly ash, respectively, in a layer system may be used for
treating the calcium fluoride sludge leachate under flowing conditions. The
acidic and basic fly ashes are effective in reducing the magnesium and the
organics whereas kaolinite and illite are effective for the calcium, kaolinite
for copper and illite and kaolinite for fluoride based upon a comparison of
their sorbent capacities. The basic fly ash is recommended, even though it is
not as effective as the acidic fly ash, for removal of copper and magnesium
because it can retain the copper and magnesium ions that are initially leached
from the acidic fly ash. This leaching occurs until the effluent from the
acidic fly ash lysimeter becomes basic as a result of prolonged passage of the
alkaline fluoride sludge leachate through the column.
Based upon a comparison of all sorbent capacities, the combined use of
the relatively expensive sorbents, activated alumina and activated carbon,
may be more effective in reducing the above cations, anions, and organics in
the calcium fluoride sludge leachate than the inexpensive ashes and clays.
The activated alumina reduces the levels of the calcium, copper, magnesium and
fluoride and the activated carbon is effective in reducing the organic concen-
trations. However, the usefulness of the activated alumina for treating this
leachate is limited by the marked reduction observed in its permeability as
the calcium fluoride sludge leachate flows through this sorbent. A point can
be reached where the activated alumina is impermeable to the flow of this
sludge leachate.
The combination of illite, kaolinite, and vermiculite, respectively, in
a layered system may be used to treat the metal finishing sludge leachate
under flowing conditions. Illite and vermiculite are effective for reducing
the concentrations of calcium, copper, magnesium, nickel, and the organics.
Vermiculite, although not as effective as the illite, is used to retain the
calcium and copper ions which are initially leached from the illite. This
occurs until the illite becomes alkaline due to prolonged passage of the alka-
line metal finishing sludge leachate through this sorbent. The kaolinite is
effective for reducing the fluoride ion levels in this leachate.
The combination of the activated alumina and activated carbon can also be
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used to treat the metal finishing sludge leachate. The activated alumina is
found to be effective in reducing the calcium, magnesium and fluoride ions, and
the activated carbon is effective in reducing the copper, nickel and organics.
However, the clay sorbent combination, rather than the more expensive activa-
ted alumina and activated carbon combination, is more effective in reducing
the contaminant levels measured in this leachate.
The combination of basic fly ash, vermiculite, and kaolinite may be used
to reduce the measurable contaminants present in the petroleum sludge lea-
chate. Basic fly ash is effective in reducing the copper and the fluoride ion
concentrations based upon an examination of the sorbent capacities. Vermicu-
lite is effective for the calcium, zinc, cyanide and the organics, and kaoli-
nite is effective for the magnesium ions. The combination of activated alumi-
na and activated carbon can again be used to reduce the measurable contami-
nants in the petroleum sludge leachate. The activated alumina is effective
for the calcium, copper, magnesium, and fluoride ions, and the activated carbon
is effective for the zinc and cyanide ions as well as the organics. However,
their sorbent capacities, as was the case for the metal finishing sludge lea-
chate, are again significantly lower than the ash and clay sorbent combina-
tions.
In summary, the removal of organics from the calcium fluoride leachate is
best accomplished by the use of activated carbon. However, with regard to the
metal finishing and petroleum sludge leachates, illite and vermiculite, res-
pectively, are the most effective for treating the organics.
The behavior of a sorbent with regard to the removal of a particular con-
taminant varies with the type of leachate being treated. This effect may
result from the competitive ion exchange and sorption processes which exist
among the constituents of a leachate and the sorbent and cannot be easily pre-
dicted on the basis of results obtained from the use of synthetically consti-
tuted leachate. This latter point serves to emphasize the choice of an actual
industrial sludge leachate rather than a synthetically constituted leachate if
one wishes to draw predictive conclusions regarding the effectiveness of sor-
bents in reducing the contaminants in an industrial sludge leachate.
The experimental conditions, a 2.5 gram of concentrated leachate mixed
with 1 gram of sorbent for 24 hours, did not provide results that were in
agreement with some of the results obtained under flowing conditions but were
useful in indicating promising sorbents. In general, the sorption capacities
exhibited by a sorbent for a specific constituent in a leachate, under flowing
condition, was significantly higher than that achieved under non-flowing con-
ditions. In some cases no removal of specific constituents by a sorbent was
observed under non-flowing conditions but significant removals were observed
under flowing conditions.
The pH of the leachate is a factor in the leaching and removal of consti-
tuents by a specific sorbent. The pH of the effluent leachate, after prolong-
ed passage through the lysimeter, approaches that of the influent leachate.
Some sorbents are more effective in removing specific cations under alkaline
conditions than acidic conditions. Acidic fly ash leaches cations into the
leachate under acidic conditions, but under alkaline conditions it effectively
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removes these constituents. When this occurs, another sorbent, such as basic
fly ash, should be used in combination with the acidic fly ash in a layered
system to remove the constituents being leached out. This leaching will de-
crease to insignificant levels when the effluent from the acidic fly ash be-
comes alkaline.
The permeabilities exhibited by the sorbents are a significant factor in
the removal of the contaminants from the three leachates studied. The coeffi-
cients of permeability for the clays were so low that mixtures of 20 percent
clay and 80 percent sand were used to obtain adequate flows of leachate
through the sorbents in the lysimeters.
The coefficients of permeability for most of the sorbents, with the ex-
ception of activated alumina, kaolinite, and bottom ash, remained fairly con-
stant for both the calcium fluoride sludge leachate and petroleum sludge lea-
chate. The coefficient of permeability for kaolinite exhibited a decrease but
it was not as marked as the decrease in the coefficient of permeability for
the activated alumina and bottom ash upon the addition of these leachates.
For the cases of the metal finishing sludge leachates, most of the sorbents
exhibited a decrease in the coefficient of permeability with the exception of
the activated carbon. The coefficient of permeability for this sorbent re-
mained fairly constant for all three types of leachate. The marked decreases
in the coefficient of permeabilities may result in ponding when the mixtures
containing these sorbents are used to treat the leachate studied unless pro-
visions, such as the addition of inert materials to these sorbents, are made
to minimize these decreases in permeability.
The composition and concentration of constituents in the industrial
sludges collected over a period of a year show considerable variations lead-
ing, in some cases, to wide fluctuations within the leachate. Thus, the
selection of sorbents to treat these leachates must take into account the
changes in composition and concentrations that can be encountered.
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SECTION 3
RECOMMENDATIONS
A test, preferably under non-flowing conditions, must be devised for
predicting the effectiveness of the sorbents selected for removing specific
constituents from industrial sludge leachates. This may be achieved by
identifying the desired properties such as clay type, inorganic composition
and carbon content in naturally occurring sorbents located in the vicinity of
the landfill. Under flowing conditions, evaluation of a sorbent in a lysi-
meter is time consuming and requires analysis of a large number of samples.
Means for handling suspended solids present in the leachate must be de-
vised to minimize the clogging of the sorbent bed in the field. In this
study, the suspended solids in the leachates (generated from the industrial
sludges) were removed prior to treatment.
Each sorbent was evaluated separately in the treatment of the various
types of industrial sludge leachates. Since a combination of sorbents must be
used in a single bed for treating the leachate, the removal capacity of these
combinations in a single column must be evaluated.
The influence of variations in weather conditions such as temperature, pH
of precipitations, etc., on the removal processes must be studied. For exam-
ple, pH has been shown to be a factor in the leaching - removal process.
Since it is well known that the pH of precipitation can vary dramatically with
locality (15), process development must define and design for this effect.
Since these naturally occurring sorbents show promise for removal of
cations, anions, and organics from the leachates studied, an investigation
should be carried out using these inexpensive natural sorbents rather than
refined sorbents such as activated carbon for tertiary treatment of waste
streams. Fly ash has been studied extensively for this purpose, but its use
as part of a sorbent mixture has not been examined. Also, the sorbents could
be used in sand beds or mixed media filters. The low cost of these sorbents
warrants their being discarded rather than being regenerated, as in the case
with activated carbon.
The application of sewage treatment effluents to agricultural soils has
been handicapped by the presence of trace amounts of toxic cations and anions
in this effluent. The naturally occurring sorbents and waste products should
be tested with the agricultural soils to determine whether these sorbents can
provide an inexpensive means of tying up these toxic substances before they
can contaminate ground or surface waters or be incorporated within the vegeta-
tion.
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The selection of sorbents used in this study was limited by time and
financial considerations. Other sorbents should be looked at. For example,
in our study, alumina was shown to have a great affinity for a large number of
cations and anions; however, its low permeability negated its usefulness as a
sorbent. By choosing a naturally occurring soil or waste materials such as
red mud, etc. with a high alumina oxide content or by admixing with sand, this
permeability problem can be overcome.
Likewise, the choice of industrially generated sludges used in this study
led to a limited number of measurable contaminants being encountered in the
leachate. Sorbent combinations for the treatment of only calcium, magnesium,
copper, nickel, zinc, fluoride cyanide and organics have been defined. Addi-
tional industrial sludges whose leachate contains significant concentration of
cadmium, chromium, lead, iron, mercury, arsenic, antimony, tin, strontium,
etc. should be examined to define the sorbent combinations that can be used to
treat these contaminants.
The results of this additional work could provide a list of promising sor-
bent combinations that may be recommended to industry for treating the heavy
metal, toxic anions and organics encountered in their sludge leachate.
8
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SECTION 4
MATERIALS DESCRIPTION
SORBENTS
The sorbent materials that were selected for this study are bottom ash,
fly ash, zeolite, vermiculite, illite, kaolinite, activated alumina, cullite,
and activated carbon. The selection of these materials was based on the con-
sideration of three factors, namely, (1) economics, (2) availability, and (3)
removal potential.
Fly Ash
Fly ash is a waste product of fossil fueled power generating plants and
is collected by electrostatic precipitators from the fuel gases before they
enter the stacks. This material is generally dark gray in color and is com-
posed of constituents present in coal or their combustion products. Physical-
ly, it is a fine gritty substance with the individual particles ranging from
0.5 to 100 microns. The principal chemical constituents of fly ash are
silica, alumina, iron oxides, sulfur trioxides, and alkali and alkaline earth
metals. Approximately 30 million tons of fly ash is produced annually in
this country; only 17.4% is eventually utilized, and the balance is disposed
of in landfills. The samples, both acidic and basic, used for this study were
supplied by Public Service Electric & Gas Company, Hudson Generating Station,
Jersey City, New Jersey.
Bottom Ash
As in the case of fly ash, bottom ash is also a waste product of fossil
fueled power generating plants and is collected as a residue of the furnace.
This material is generally dark gray in color and is also composed of consti-
tuents similar to those present in fly ash. However, the individual particle
is much larger than that of fly ash. The samples used for this study were also
furnished by Public Service Electric & Gas Company, Hudson Generating Station,
Jersey City, New Jersey. The material as received contained grain sizes rang-
ing from 150 microns to 1/2 inch. They were ground to pass a sieve size of 80
mesh before use.
Zeolite
Any mineral belonging to the zeolite family of minerals and synthetic
compounds is characterized by an aluminosilicate tetrahedral framework and
loosely held water molecules, permitting reversible dehydration. Zeolites
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have been extensively studied from theoretical and technical standpoints be-
cause of their potential and actual use as molecular sieves, catalysts, and
water softeners. Zeolites are low temperature and low-pressure minerals found
in aurygdaloidal basalts and also as authigenic minerals in sandstones and
other sediments. These materials are usually white in color. After consider-
ing potential sorption characteristics, as well as availability, zeolite was
selected for the present study. The sample used was from Brickhorn, New
Mexico, and was furnished by the Double Eagle Petroleum and Mining Company,
Casper, Wyoming. Physically, the material is light tannish-white in color
and has a powder-like texture. The sorbent was used as received.
Kaolinite
The structure of kaolinite is composed of a single silica tetrahedral
sheet and a single alumina octahedral sheet combined in a unit. It is the
principal mineral of the kaolinite group of clay mineral. The mineral kaoli-
nite has a moderately low cation-exchange capacity (5-15 milliequivalent per
100 g). Broken bonds around the edges of the silica-alumina units are the
major cause of this exchange capacity. Kaolinite may form under acid condi-
tions at low temperatures and pressures. It is a principal component of
lateritic-type soils. Kaolinite has been used extensively in the ceramics
industry and in paper products. The selection of this sorbent material was
principally due to its importance in clay family as well as its potential
sorptive properties and availability. This material was furnished by Georgia
Kaolin Company, Elizabeth, New Jersey. Physically, it is tannish-white pow-
der. It was used as received.
Vermiculite
This micaceous mineral exfoliates when heated or subjected to certain
chemical reactions. It is a hydrated magnesium aluminum iron silicate. The
structure of vermiculite consists of trioctahedral mica sheets separated by
double water layers and is unbalanced by substitution of aluminum for tetra-
hedral layer. The resulting charge deficiency is satisfied by exchangeable
cations which occur chiefly between the mica layers. Vermiculites have a high
cation-exchange capacity (150 mi Hi equivalents per 100 g). They also adsorb
certain organic molecules between the mica layers. It is frequently listed as
an alternate product of biolite mica in ancient sediments. Vermiculite is ex-
tensively used in many industries, including fireproofing, insulation, ferti-
lizer conditioners, and packing materials. This material was used as received
and was obtained from W.R. Grace & Co., Trenton, New Jersey.
mite
The term illite is used to denote the aluminum, magnesium, and iron rich
mica found in the clay fraction of weathered shale in Illinois. The basic
structural unit is composed of two silica tetrahedral sheets with a central
octahedral sheet. The size of naturally occurring illite particles is very
small with well-defined edges. The illites have a moderate cation-exchange
capacity (20-30 milliequivalent per 100 g). It is primarily due to broken
bonds, but lattice substitution may also be a cause in poorly crystallized
varieties. Illite is a common product of weathering and is particularly
10
-------
abundant in deep-sea clays. The sample used for this study was obtained from
A.P. Green Refractory Co., Morris, Illinois.
The material received was in rock form and was ground to powder that
passed through an 80-mesh screen before use.
Activated Alumina
Activated alumina is a highly porous, granular form of aluminum oxide with
preferential adsorptive capacity for moisture and odor. Sizes range from powder
to 1.5-inch diameter particles. In this study, particle sizes less than
.045 mm and in the size range from 0.147 mm to 0.295 mm were examined. Acti-
vated alumina has been used as a desiccant for gases and vapors in the petro-
leum industry. It is also used as a catalyst or catalyst carrier. The sample
studied was furnished by Alcoa, Bauxite, Arkansas.
Activated Carbon
Activated carbon is a manufactured form of carbon with high adsorptivity
for gases, vapors, and colloidal solids. It is obtained by the destructive
distillation of carbonaceous materials and activated by heating to 800-900°C
with steam or carbon dioxide. This results in a porous internal honeycomb-
like structure. The specific area of air activated carbon is generally very
large, ranging from 600 to 2000 square meters per gram. Although capable of
adsorbing large amounts of water vapor, activated carbon finds its major use
in solvent recovery, odor and taste removal, and as a catalyst and catalyst
carrier. The sample (Grade 718, Granular) was obtained from Witco Chemical,
Activated Carbon Division, New York, New York.
Cullite
Cull He is a commercial name of a synthetic zeolite. It is a chemically
bound mixture of oxides of sodium, aluminum, and silicon. Physically, it has
a white granular form, ranging from 16 to 40 mesh. The primary use of this
material is in water softening. This material was selected primarily due to
potential capacity as a reference point of synthetic sorbent material. The
sample used in this study is called "High Capacity Cullite", abbreviated
"Cullite" hereafter. The sample was supplied by Culligan U.S.A., Northbrook,
Illinois.
SLUDGE SOURCES
The calcium fluoride sludge used in this study is the result of lime pre-
cipitation of fluoride in waste streams from etching processes used in the
electronics and aircraft industries. Three samples designated as #1, #2, and
#3 were collected over a period of a year to determine how changes in produc-
tion schedules and process influence the composition of the leachate generated
from this sludge.
The metal finishing sludges designated as #1, #2, and #3 were also collec-
ted over a year and are the result of alkaline treatment of a waste stream from
11
-------
a metal finishing plant.
Storage tank bottoms and the API separator were the source of the petro-
leum sludge #1 and #2 generated by refineries.
12
-------
SECTION 5
EXPERIMENTAL PROCEDURES
PREPARATION OF SORBENT MATERIALS
All sorbent materials were used as received. Sorbent materials which
were not obtained as a powder (illite, bottom ash, and vermiculite) were
ground in a laboratory hammer mill (Weber Bros, and White Metal Works, Inc.
Type 22) and passed through an eighty mesh A.S.T.M. standard sieve. All sor-
bents were dried to constant weight at 103°C (in accordance with "Standard
Method" procedures; 13th Ed., 1971, A.P.M.A.) and stored in a desiccator until
used.
PREPARATION OF BACKGROUND LEACHATES FROM SORBENTS
Background leachates of all sorbents except vermiculite were prepared
using deionized water and dried sorbent material in the ratio of 2.5 ml water
per gram of sorbent material and agitated in a Burrell Shaker for 24 hours at
ambient temperature. Our studies revealed that saturation of the mixture with
respect to total dissolved solids as measured by conductance was achieved in
24 hours. The vermiculite leachate was prepared in ratio of 10 ml of water to
one gram of sorbent material because all the water was taken up by the vermi-
culite and none was available for analysis when the 2.5 to 1 ratio was used.
The resultant mixture was then filtered using a glass fiber filter (Reeve
Angel Type 934A; 1.6 microns pore size) in order to remove all undissolved and
non-filterable solids. The filtrates (leachates) were then analyzed according
to procedures described later.
PREPARATION OF SLUDGE LEACHATES
A sample of each type of sludge was dried at 103°C to constant weight in
order to determine its moisture content. In the case of the calcium fluoride
and metal finishing sludges, the unaltered sludge was then mixed with deion-
ized water in a ratio of 2.5 ml water per gram of dried sludge (as defined by
the above moisture content determination) and mechanically stirred for 24
hours. The above ratio used in the test was arrived at after a series of
trial ratios were carried out. This involved decreasing the quantity of water
in the mixture until maximum sludge leachate concentrations were achieved.
The petroleum sludge leachates presented a filtration problem because of
the extremely high concentration of oils and greases present in the sludge.
Thus, a higher mixture ratio (i.e. 10 to 1) of water to sludge was employed.
Ratios less than this were extremely difficult to filter. All suspensions,
13
-------
with the exception of the metal finishing sludge leachate, were filtered
through a glass fiber filter (Reeve Angle Type 934A) after stirring. The
resultant filtrates were analyzed, stored in screw-capped plastic bottles or
carboys at ambient temperatures until used.
The metal finishing sludge leachate was prepared by filtering the suspen-
sion with a Trommel Rotary Vacuum Laboratory Filter (Fabricators, Inc., of
Piscataway, New Jersey) using newsprint paper, because of the slow rate of
settling of the solid encountered with this sludge. This leachate was then
passed through a glass fiber filter to remove any nonfilterable residue, ana-
lyzed and stored in plastic carboys at ambient temperature until used.
All leachates were analyzed again just before use, even though stored
leachate samples failed to exhibit any significant changes in contaminant
concentration.
STATIC STUDIES
Into a tared, one liter screw-capped, polypropylene Erlenmeyer flask was
placed 100 grams of dried sorbent material. To this was added 250 ml of
sludge leachate. To the vermiculite, 1000 ml of sludge leachate was added
because the 250 ml amount of leachate initially added was absorbed by this
sorbent and none was left for analysis after filtration. 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 filtered the filtrate was
analyzed. Vermiculite, illite and kaolim'te were used as a mixture containing
80 grams of inert Ottawa sand and 20 grams of sorbent (see Tables 3,7, and
10). These mixtures were required in the dynamic studies to increase the
permeability of these sorbents to acceptable levels (see the following sec-
tion). Thus, these mixtures were used in the static studies to provide a
basis for comparing the static results with the lysimeter results.
DYNAMIC STUDIES
In order to simulate dynamic conditions, lysimeter studies were conducted
using 500 g of sorbent material, except for activated carbon where 250 g pro-
vided approximately the same column height. The sorbents, vermiculite, il-
lite, and kaolim'te, were prepared as a mixture consisting of 80 percent inert
Ottawa sand and 20 percent clay. This ratio was arrived at after a series of
studies established that this would permit adequate flows of leachate through
these sorbents. "Pure" clay lysimeters did not exhibit adequate permeability
characteristics.
Lysimeters were constructed of plexiglass tubing (6.2 cm i.d.; 0.6 cm
wall thickness; 90 cm length), supported in a vertical position. The labora-
tory arrangement of the lysimeters are shown in Figure 1. A 164 micron pore
size corundum disc (6.10 cm diameter; 0.6 cm thickness) was placed in each
column, directly over the drain hole in order to prevent clogging of the out-
let and also to support the sorbent material. The column was packed with the
preweighed sorbent, placing 3 to 4 cm of Ottawa sand below and above the sor-
bent to prevent disturbing the geometry of the sorbent column during addition
of leachate or water. The packed column was then slowly wetted with leachate
14
-------
Figure 1. Laboratory Arrangement of Lysimeters
to allow total saturation and to force all entrapped air in the soil voids
out of the column packing. After a saturation period of at least 24 hours,
the column was then filled with leachate to the level of an overflow drain,
which had been trapped into the top side of the column, to permit a constant
head condition. Leachate was fed to the top of the column through a valved
manifold that distributed the leachate to 10 lysimeters simultaneously,
from a central reservoir. The central reservoir, a 100-liter polyethylene
carboy, delivered the leachate to the manifold system by means of a gravity
syphon feed arrangement. Any overflow from the constant head drains was col-
lected and pumped back up to the central reservoir. All tubing in the system
was made of Tygon tubing (3/8" i.d.). A constant hydraulic head was main-
tained in the lysimeters at all times, and the volume of leachate passing
through the columns was continuously monitored. Samples of leachate effluent
were collected at intervals and analyzed to determine the concentration of
all measurable constituents remaining in the effluent after a known volume of
leachate had passed through the column. This was continued until break-
through for all measurable contaminates had occurred or excessively low
permeabilities were encountered. Break-through is defined as that condition
when the concentration of the species of concern in the collected effluent
sample approached or exceeded that in the influent.
15
-------
ANALYTICAL PROCEDURES
The constituents in the leachate generated from each sludge were initial-
ly identified using emission spectroscopy and x-ray fluorescence. Their con-
centration was then determined using atomic absorption and specific ion
probes. The concentration of organics was determined using total organic
carbon and chemical oxygen demand measurements. pH and conductivity measure-
ments were also carried out on the leachate to further characterize the sam-
ples.
pH Measurements--
The pH of the samples was measured by means of an Orion Model 701 Digital
pH/mv Meter using an Orion combination pH electrode, Model 91-02.
Conduct! vi ty~
Measured,using a Beckman conductivity bridge (Model RC16B2) together with
a specific conductance cell having a cell constant of 1.
Chemical Oxygen Demand (COD)«
An automated procedure based on the manual method described in "Standard
Methods" was employed in the determination of COD. The sample was digested
with a potassium dichromate - sulfuric acid digestion mixture, and the deple-
tion of the hexavalent chromium (due to the oxidation reaction with the sam-
ples) was measured colorimetrically. This automated analysis was performed
using a Technicon Autoanalyzer II (Industrial Method Number 137-71W).
Total Organic Carbon (TOC) —
Measured by use of the Dohrmann Envirotech DC-52D Carbon Analyzer.
Determination of Anionic Species--
The analysis for the anions Cl~, F", CN~ were as follows:
Chloride ion analysis—Analysis of chloride ion was conducted using a
chloride ion electrode (Orion Model No. 94-17) in combination with a single
junction reference electrode (Orion Model No. 90-01) connected to an Orion
Model 701 digital/mv meter. This electrode responds directly to chloride ion.
The chloride ion concentration of a sample solution was determined directly by
comparing the electrode potentials obtained using standards of known chloride
ion content. Straight-line calibration curves were obtained over the range of
1 to 1000 ppm using reagent grade sodium chloride.
Fluoride ion analysis—Analysis of fluoride ion was carried out using a
fluoride ion electrode (Orion Model 94-09) in combination with a single junc-
tion reference electrode (Orion Model 90-01) connected to an Orion Model 701
digital pH/mv meter. The fluoride content of a sample solution was determined
directly by comparing the electrode potential reading in the sample solution
to electrode potentials obtained in standards of known fluoride content.
Straight-line calibration curves were obtained over the range of 0.1 ppm to
1000 ppm using reagent grade sodium fluoride. A total ionic strength adjuster
buffer containing 1,2-cyclohexylenedinitrilotetraacetic acid (Orion Cat. No.
94-09-09A) was used in the ratio of one part reagent to one part sample for
all fluoride ion measurement. This reagent will "swamp out" variations in the
16
-------
levels of other ions present in the solution as well as destroy polyvalent
cation complexes of fluoride by preferentially complexing these cations.
Therefore, total fluoride was measured.
Analysis of cyanide ion—Analysis of cyanide ion was conducted using a
cyanide ion electrode (Orion Model 900100) connected to an Orion Model 701
digital pH/mv meter. This electrode responds directly to cyanide ion activi-
ty, without regard to sample ionic composition, total ionic strength, pH or
complexing species. The free cyanide ion content of a sample solution was
determined directly by comparing the electrode potentials obtained using stan-
dards of known free cyanide ion content. Semi-logarithmic calibration curves
were obtained over the range of 0.01 to 10 ppm using reagent grade socnum
cyanide. All solutions were adjusted with 10M NaOH to concentrations of 0.1M
in NaOH.
Determination of'Metals--
The concentrations of the various metals reported (i.e. Ca, Cd, Cr, Cu,
Fe, Mg, Ni, Pb, Zn) were determined using a Varian Techtron Atomic Absorption
Spectrometer (Model 1200) according to E.P.A. procedures (16). The reference
solutions used to construct calibration curves in these determinations were
made up using deionized water with a specific resistence of 18 Megohm-cm
(25°C).
PERMEABILITY STUDIES
After a steady flow condition through the column was established, volume
throughput per second was recorded. The permeability coefficient, k, was then
calculated by means of the following equation (17):
k = (QL)/(aht)
where a = Cross-sectional area of soil column
Q = Total quantity of water which flowed through the soil column in
elapsed time, t.
h = Total hydraulic head, i.e., distance from the bottom drain to the
top of the leachate level corresponding to the level of the top
overflow drain.
1 = Length of soil sample in the lysimeter.
t = Total elapsed time in seconds for quantity collected, Q.
Permeability tests were conducted each day, until break-through had been
achieved. In certain cases, where the flow through the lysimeters ceased, the
studies were discontinued even though leachate analysis indicated that the
sorbtive capacity of the soil column was not yet exhausted.
GRAIN SIZE DETERMINATION
The test procedure for grain size determination follows: For large grain
17
-------
sorbents (i.e. >200 mesh) sieve analysis was performed. For those sorbents of
a fine particle size (<200 mesh) the hydrometer test was used to determine
grain size. For mixed size composition a combined analysis was used.
Sieve Analysis--
A sieve analysis consists of passing a sample through a set of sieves and
weighing the amount of material retained on each sieve. The sieves used were
specified according to ASTM.
Hydrometer Analysis--
The hydrometer analysis is based upon Stokes' law, which relates the ter-
minal velocity of a sphere falling freely through a fluid to the diameter. It
is assumed that Stokes1 law is valid to a mass of dispersed solid particles of
various diameter and shapes. The hydrometer is used to determine the percen-
tage of dispersed particles remaining in suspension at a given time. The
grain size equivalent to a spherical particle is computed for each hydrometer
reading using Stokes1 law.
The results of both sieve and hydrometer analysis were plotted in the
form of a grain-size distribution curve on a semi-logarithmic chart (see
Figure 2). The grain size distribution curve was obtained by plotting parti-
cle diameter on the logarithmic abscissa and the percent finer by weight on
the arithmetic ordinate. The grain diameter whose size is greater than that
of 10 percent of the particles by weight is called the effective diameter be-
cause of the influence of the smaller grain sizes on soil properties. In
order to demonstrate the characteristics of gradation, the two most commonly
used indices are the uniformity coefficient and the coefficient of curvature.
The uniformity coefficient is defined as the ratio of the size of the 60 per-
cent particle diameter, by weight, to the effective diameter, i.e.,
Cu= (D60)/(D1Q).
The coefficient of curvature,
Cz - [(D30)2]/[(D6())(D10)],
is a value that can be used to identify such samples of poorly graded mater-
ials. The reader is referred to standard texts of soil mechanics for a more
detailed explanation (17).
18
-------
100
80
60
m
—j en
vo ac
20
10
1.0
0.1 0.01
GRAIN SIZE (mm)
Activated Alumina
Activated Carbon
Bottom Ash
Cullite
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
Kaolinite
Vermiculite
Zeolite
0.001
Figure 2. Grain-Size Distribution of Sorbents.
-------
SECTION 6
RESULTS AND DISCUSSION
Three calcium fluoride sludges and three metal finishing sludges were
collected over a one-year period in order to determine the magnitude of
changes in the concentration of the constituents due to changes in production
schedules and manufacturing processes. Comprehensive analyses were performed
in accordance with "Standard Methods" on leachates generated from these'
sludges. Petroleum sludges were collected from two separate sources, a stor-
age tank bottom and API gravity separator, to determine the effect of two
different sources of petroleum sludge on the composition and concentration of
the constituents in their respective leachates.
The heavy metals present in the leachates from the different sludges
were found to be copper, chromium, cadmium, iron, nickel, lead, and zinc.
Their concentrations are listed in the first column of Tables 1 to 3, 5 to 7,
9, and 10. The concentrations of calcium and magnesium were also measured
because they contribute to the hardness in water. The concentrations of
chloride, fluoride, and cyanide ions were also determined because their pre-
sence in water in sufficient concentrations can lead to its rejection as
potential drinking water. As described earlier, this study is divided into
two phases; namely, the static study and dynamic study.
RESULTS OF STATIC STUDIES
Calcium Fluoride Sludge Leachate
Analysis of the leachate prepared from the three calcium fluoride sludge
samples collected over a period of one year indicated that most variations in
concentrations of the measured constituents are within a factor of two with
the exception of cyanide (see Tables 1 to 3). Cyanide was not found in sig-
nificant quantities in sludge sample #3 (see Table 3), the most recent one
collected, because the use of cyanide in the production processes was discon-
tinued during the study year period. This was established through discus-
sions with plant personnel at the place where the sludge was obtained after
it was determined that amounts of cyanide found in the leachate prepared from
sludge sample #3 were significantly lower than those encountered in sludge
leachates #1 and #2.
Further examinations of the concentration levels of the constituents in
the leachate prepared from the fluoride sludges reveal that the calcium, mag-
nesium, copper, nickel, fluoride, and cyanide and organic concentrations (as
indicated by COD and TOC) are significant. However, cadmium (with the
20
-------
exception of sludge #1 leachate) Iron, lead, chromium, and zinc are found at
concentration levels that do not differ significantly from the minimum concen-
tration levels that can be readily measured using the atomic absorption
spectrometer and specific ion probes.
The sorbent capacity of eleven natural and refined sorbents for the re-
moval of constituents in the leachate is represented in Tables 1 to 3 for each
of the constituents that exist in the leachate at measurable levels. This
data was obtained by subtracting the amount of each constituent remaining in
the leachate after treatment with sorbent, from its initial concentration and
dividing by the amount of sorbent used. Both acidic fly ash and activated
carbon were not evaluated using leachate #1 (see Table 1) and leachate #2 (see
Table 2) but were examined using leachate #3. During our static studies on
leachate #1 and leachate #2, only the basic fly ash was available. Also, our
limited supply of activated carbon was depleted due to the unanticipated large
amounts required for these studies. Since we had collected a limited amount
of sludge, we were unable to prepare leachate #1 and leachate #2 to evaluate
the activated carbon and acidic fly ash once we obtained sufficient supplies
of these sorbents.
An examination of the static study data (see Table 1, Table 2, and Table
3) resulting from the mixing of eleven sorbents with three types of leachate
suggests the following observations: The sorbent exhibits a capacity for a
specific contaminant and may be used to remove this contaminant from the
leachate. The sorbent exhibits no capacity for a contaminant in the leachate
but the amount of t^his contaminant that is leached from the sorbent when it is
mixed with the leachate is significantly less than the amount obtained when it
is mixed with water (see sorbent capacities designated as L). Finally, the
sorbent exhibits no capacity for the contaminant and no reduction in leaching
is observed when it is mixed with the leachate. For example, the acidic fly
ash (see Table 3) exhibits a sorbent capacity of 105 mg of COD removed per
gram of acidic fly ash used. For the case of the calcium, copper and fluoride
ions, this sorbent exhibits no removal capacity but the concentration of these
ions after treatment 1s significantly less than the mathematical sum of the
concentration of these ions in the influent sludge leachate and that which is
leached from the sorbent with water. Perhaps, the addition of a slightly
alkaline leachate or the presence of contaminants in the leachate reduces the
leaching potential of the calcium, copper, and fluoride ions from the sorbent.
me acidic fly ash exhibited no removal capacity for the nickel ion since the
sum of the nickel ion concentration in the sludge leachate and that which can
oe leached from the sorbent is equal to the effluent concentration level of
mckel ion after treatment.
. The sorbent capacities are listed in Table 4 for both the static and the
lysimeter tests. The sorbent .capacities are considered to include the removal
ctnH ies related to such processes as ion exchange, adsorption, etc. A
rana-2- the sPecific removal processes such as the determination of exchange
im/ 1- s °r 9enerat1on of sorption isotherms was not carried out in this
investigation because it would be necessary to modify the sludge leachate by
altering the contaminant concentration to obtain this data.
21
-------
TABLE I : STATIC STUDY RESULTS OF CALCIUM FLUORIDE SLUDGE LEACHATE II
ro
ro
Initial
Condition Fly
Measured of Bottom Ash Activated Activated
Minimum
Detectable
parameters L
pH
Conductivity
Ca (mg/1)
Cd (mg/1)
Cr (mg/1)
Cu (mg/1)
Fe (mg/1)
Hg (rag/1)
N1 (mg/1)
Pb (mg/1)
Zn (mg/1)
f (rag/1)
Cl" (mg/1)
CtT (mg/1)
COO (mg/1)
TOC (mg/1)
eachate Description* Ash
fi , 1) 7.2
6'3 ?| 6.0
2680 }1
400 2
3
1
0.08 2
3
0.25 J2
3
1
0.22 2
3
0.10 2
{?
11.0 li
3
0.22 2
3
<0.20 2
3
0.02 2
3
6.1 2
3
58.5 2
3
0.60 2
3
76.0 2
3
) 2780
5200
20.0
385
37.5
<0.01
<0.01
0.18
<0.20
0.25
0
0.25
0.10
0.30
<0.05
0.10
0
93.2
52.0
A
<0.05
0.15
0.18
<0.20
<0.20
<0.01
0.10
0
0.31
2.5
9.0
500
470
L
0.07
0.48
0.30
40.3
79.8
L
16.5 (2) 16.3
(3) 0
(Basic)
8.5
10.0
2500
2990
300
485
L**
<0.01
<0.01
0.18
0.50
0.80
0
0.06
<0.03
0.48
<0.05
<0.05
0.13
3.2
1.0
25.0
<0.05
0.10
0.30
0.28
0.28
L
<0.01
0.02
0
1.7
2.2
9.8
9.5
60.0
L
0.04
0.56
0.10
4.8
36.8
93.5
4.1
0
41.3
Zeolite
7.8
7.4
81 50""
7000
6.0
135
663
<0.01
0.03
0.13
0.30
0.30
L
0.07
0.05
0.43
<0.05
0.15
0
169
6C.O
<0.05
0.15
0.18
0.28
0.25
L
0.03
C.04
L
0.51
1.7
11.0
12.6
180
0
0.04
0.54
0.15
'26.6
76.0
L
0
16.4
0
Verraiculite
8.1
7.3
182
2800
1.5
400
0
<0.01
<0.01
0.70
<0.20
<0.20
0.50
<0.03
0.07
0.15
<0.05
0.10
0
4.7
20.2
L
<0.05
0.13
0.09
<0.20
<0.20
<0.01
0.03
0
1.2
5.9
0.20
2.9
56.0
2.5
<0.03
0.50
0.10
13.0
53,2
22.8
2.1
10.9
5.6
Illite
3.0
3.0
4" 60
4400
' 2.S
335
163
0.06
0.06
0.05
0.70
0.80
L
3.6
3.7
L
2.2
2.3
0
' 70.0
48.0
L
0.65
0.75
L
0.33
0.29
L
1.5
1.7
0
0.33
0.64
13.7
'2!7 '
40.0
46.3
<0.03
0.15
1.1
15. '8
48.0
70.0
0
0
41.3
Kaolin He
5.1
4.2
295
1980
""42.0
355
113
<0.01
<0.01
0.18
0.30
0.25
L
" 0.16
0.29
L
<0.05
0.10
0
4.9
14.0
L
<0.05
0.25
0
<0.20
<0.20
0.27
0.06
L
2.3
3.1
7.5
6.8
50.0
21.3
1.2
1.6
L
7.0
140
0
IS. 5
26.0
0
Aluraina(I)
9.8
8.6
1790
3590
-------
TABLE 2 : STATIC STUDY RESULTS OF CALCIUM FLUORIDE SLUDGE LEACHATE K
ro
CO
Initial
Condition
Measured of Bottom
Parameters Leachate Description* Ash
PH
Conductivity
Ca (mg/1)
Cd (mg/T)
Cr (mg/1)
Cu (mg/1)
Fe (mg/1)
Hg (mg/1)
N1 (mg/1)
Pb (mg/i;
Zn (mg/1)
r (mg/1)
el' (rag/1)
CfT (mg/1)
COD (mg/1)
TOC (mg/1)
75 S1 7>1
7'5 (2 7.2
3080
365
<0.01
0.30
0.49
1 Z780
2 5950
1 20.0
2 2.61
3 260
1 <0.01
2 <0.01
3
1 <0.20
2 0.30
3 0
[]) O.Z5
2) 0.20
3) 0.73
(1) <0.05
<0.05 (2 <0.05
(3
5.0
0.10
0.38
0.02
5.9
78.0
0.42
88.5
8.5
1 93.2
2 96.6
3) L
1) <0.05
2) <0.05
3 0.13
1 I <0.20
2) 0.33
3) 0.13
V <0.01
2) 0.04
3) 0
Vi 0.31
2) 2.5
3) 8.5
1) 500
2) 482
3) L
1 0.07
2 0.47
3 0
) 40.3
2) 89.3
3 L
1 0
2) 8.5
3) 0
Fly
Ash
(Basic)
8.5
8.9
2500
3410
300
365
L
<0.01
<0.01
0.50
0.70
L
0.06
0.16
0.83
<0.05
<0.05
3.2
3.3
4.3
<0.0'»
<0.05
0.13
0.28
0.28
0.25
<0.01
<0.01
0.03
1.7
2.3
9.0
9.5
88.0
0
0.04
0.50
0
4.8
52.1
91.0
4.1
0
21.3
Zeolite
7.8
7.6
8150
11550
6.0
88.0
693
<0.01
<0.01
0.30
0.40
L
0.07
0.20
0.73
<0.05
<0.05
169
174
0
<0.05
<0.05
0.13
0.28
0.38
L
0.03
0.05
0
0.51
2.1
9.5
126
195
0
0.04
0.44
0
26.8
93.8
L
0
8.3
0
Venn1cul1te
8.1
7.3
182
3200
1.5
318
47
<0.01
<0.01
<0.20
<0.20
1.0
<0.03
0.29
0.20
<0.05
<0.05
4.7
9.7
0
<0.05
<0.05
0.05
<0.20
<0.20
1.8
<0.01
0.02
0
1.2 '
5.4
0.50
"• 2.9
80.0
0
<0.03
0.43
0
13.0
67.0
21.5
2.7
8.0
0.5
mite
3.0
3.2
4460
4150
2.5
300
163
0.05
0.07
0
0.70
0.70
L
3.6
3.8
L
2.2
2.2
0
70.0
55.0
L
0.65
0.69
L
0.33
0.38
L
1.5
1.6
0
"0.33
0.91
12.5
2.7
70.0
20.0
<0.03
0.16
0.65
15.8 '
40.0
121
1 0
0
21.3
Kaollnlte
5.1
4.3
295
2680
4Z.O
231
335
<0.01
<0.01
0.25
0.30
L
0.16
0.60
0
<0.05
<0.05
4.9
9.9
0
<0.0b
<0.05
0.13
<0.20
0.33
0.13
0.27
0.32
0
2.3
3.5
6.0
6.8
74.0
10.0
l.Z
1.1
L
7.0
140
0
15.5
18.5
L
Activated
A1um1na(l).
9.8
8.7
1790
4150
<0.10
<0.10
913
<0.01
<0.01
1.1
1.1
L
0.04
0.21
0.70
<0.05
<0.05
0.06
0.23
11.9
-------
TABLE 3 : STATIC STUDY RESULTS OF CALCIUM FLUORIDE SLUDGE LEACHATE «3
ro
Measured
Parameters
pH
Conductivity
C« (ng/1)
Cd (mg/1)
Cr (mg/1)
Cu (rog/1)
Fe (mg/1)
Hg (mg/1)
N1 (mg/1)
Pb (mg/1)
In (mg/1)
F- (mg/1)
CT (mg/1)
C)T (mg/1)
COD (mg/1)
TOC (mg/1)
Initial
Condition
of Bottom
Leachate Description* Ash
7.2
1680
318
<0.01
<0.20
0.10
<0.05
21.3
i
1
1
3
*
J
1.2
6.9
2780
4160
20.0
275
108
<0.01
<0.01
-
<0.20
<0.20
-
1) 0.25
2} 0.10
3) L
2
3
2
3
0.15 (2
(3
<0.20 (2
• (3
0.18
6.7
6S.O
0.05
44.0
16.0
r— fsj ro
I
I
i
2
3
<0.05
<0.05
93.2
90.0
L
<0.05
0.15
0
<0.20
<0.20
<0.01
0.14
0.10
0.31
3.0
9.3
500
550
0
0.07
0.06
L
40.0
80.0
0
U 0
2) 16.0
3) 0
Fly
Ash
(Acidic)
5.1
5.4
3150
3800
357
344
L
<0.01
<0.01
0.50
<0.20
0.29
0.34
L
<0.05
<0.05
64.4
98.0
0
1.40
1.55
0
0.30
0.30
0
1.6
1.8
0
1.7
7.5
L
10.0
70.0
0
0.04
0.04
0.03
<2.0
<2.0
105
0.50
0.70
38.3
* (1) Background of Sorbent Material (mg/1)
(2) Effluent Level After Treatment (mg/1)
(3) Sorbent Capacity ug Removed per g of Sorbent Used
** L Represents no Sorbent Capacity and a Reduction In
Fly
Ash
(Basic) VermlculHe
10.1
9.8
2030
2430
300
337
L
<0.01
<0.01
0.50
<0.20
<0.06
0.06
0.10
<0.05
<0.05
3.2
4.0
43.3
<0.05
<0.05
0.25
0.28
<0.20
<0.01
0.28
0
1.7
1.5
13.0
9.5
45.5
48.8
<0.03
<0.03
0.05
4.8
14.8
73.0
4.1
8.0
20.0
leaching
9.3
8.2
115
1120
1.5
266
65.0
<0.01
<0.01
<0.20
<0.20
<0.03
0.09
0
<0.05
<0.05
4.7
69.0
0
<0.05
0.50
0
<0.20
<0.20
<0.01
<0.01
2.1
1.2
7.2
L
2.9
60.0
5.0
<0.03
<0.03
0.02
13.0
39.9
4.1
Z.7
20.5
0
nine
3.0
3.2
4460
2360
2.5
325
0
<0.06
<0.01
0.70
<0.20
3.6
0.10
L
2.20
0.60
L
70.0
34.0
L
0.65
0.49
L
0.33
<0.20
1.5
0.74
L
0.33
0.31
79.9
2.7
40.0
313
<0.03
<0.03
0.25
15.8
22.9
264
0
10.3
71.3
of Contaminant When
Kaolin) te
5.1
4.5
295
1600
42.0
250
85.0
<0.01
<0.01
0.30
<0.20
0.16
0.27
0
<0.05
<0.05
4.9
23.5
0
<0.05
0.13
0.25
<0.20
<0.20
0.27
0.28
L
2.3
0.32
79.9
6.8
50.0
188
1.Z
1.2
0
7.0
40.5
43.8
15.5
21.3
L
Sorbent 1s
Activated
Alumina (I)
9.8
9.8
2790
3490
<0.10
<0.10
795
<0.01
<0.01
>o!so
0.04
0.04
0.15
<0.05
<0.05
0.06
0.10
53.0
<0.05
<0.05
0.25
<0.20
<0.20
<0.01
<0.01
0.43
Z.3
1.2
13.8
46.0
89.0
L
0.22
0.25
0
24.0
49.5
L
37.6
20.0
L
Mixed with
Activated
Carbon
9.4
8.7
575
1000
0.50
208
275
<0.01
<0.01
<0.20
<0.20
<0.03
0.09
0.25
<0.05
<0.05
0.10
12.8
21.3
<0.05
<0.05
0.25
<0.20
<0.20
<0.01
<0.01
0.43
0.04
5.2
3.8
5.0
75.0
0
<0.03
<0.03
0.05
<2.0
2.5
104
5.1
1.3
36.8
Leachate
Minimum
Detectable
Value
-
-
0.10
0.01
0.20
0.03
0.05
0.05
0.05
0.20
0.01
0.02
2.0
0.03
2.0
-
-------
TABLE 4 : COMPARISONS OF SORBENT CAPACITIES IN STATIC AND LYSIMETER TESTS
(CALCIUM FLUORIDE SLUDGE LEACHATE)
ro
in
Measured
Parameters Description*
Ca
Cd
Cu
Kg
HI
f
cr
CN"
coo
TOC
Static Test fl
Static Test 12
Static Test 13
Lysimeter Test
Static Test 11
Static Test 12
Static Test 13
lysimeter Test
Static Test 11
Static Test 12
Static Test 13
Lysimeter Test
Static Test 11
Static Test 12
Static Test 13
Lysimeter Tost
Static Test i\
Static Test 12
Static Test »3
Lysimeter Test
Static Test 11
Static Test 12
Static Test 13
Lysimeter Test
Static Test 11
Static Test 12
Static Test *3
Lysimeter Test
Static Test 11
Static Test 12
Static Test 13
Lysimeter Test
Static Test 11
Static Test 12
Static Test 13
Lysimeter Test
Static Test #1
Static Test 12
Static Test 13
Lysimeter Test
Bottom
Ash
37.5
260
108
0.18
0.30
0.73
L
L
L
L
0
0.18
0.13
0
9.0
8.5
9.3
34.4
L
L
0
0.30
0
L
~L
L
0
100
MOOO
b
Fly
Ash
(Acidic)
L
350
-
L
2.2
0
250
0
L
109
0
0.03
105
704
38.3
156
Fly
Ash
(Basic)
L"
L
L
0
0.18
0.48
0.83
0.10
0.49
25.0
4.3
43.3
172
0.30
0.13
0.25
9.8
9.0
13.0
57.0
L
0
48. 8
0.10
0
0.05
93.5"
91.0
73.0
232
41.3
21.3
20.0
62.4
Zeolite
663
693
0.13
0.43
0.73
L
0
0.18
0.13
11.0
9.5
0
0
0.1S
0
L "
L
0
0
Vermicullte 11 lite
0
47.0
65.0
84.8
0.70
0.15
0.20
0
0
L
0
0
0
0.09
0.05
0
0.2
0.5
L
2.4
2.5
0
5.0
o.lo-
0
0.02
22.8
21.5
4.1
0
5.6
0.50
0
0
163
163
0
630
0.05
0
0
L
L
L
0
L
L
L
0
L
L
L
13.7
12.5
79.9
205
46.3
20.0
313
1.1
0.65
0.25
70.0
121
264
250
41.3
21.3
71.3
88.0
Kaolinlte
113
335
85.0
1190
0.18
L
0
0
8.9
L
0
0
0
0
0.13
0.25
7.5
6.0
79.8
183
21.3
10.0
188
L
L
0
268
0
0
44.0
102
0
L
L
Activated
Alumina
(I)
99S
913
795
6300
0.18
0.48
0.70
0.15
2.9
26.0
11.9
53.0
534
0.43
0.13
0.25
11.3
11.5
13.8
348
L
L
L
0.30
0
0
L
L
L
0
L
L
L
0
Activated
Alumina
(II) Culllte
1000
913
0.18
0.48
0.70
24.8
12.4
0.35
0.13
10.5
10.8
L
L
0.15
L
0
0
0
0
1000
912
0.15
L
0.18
20.0
11.5
0.03
0.13
10.3
10.0
0
0
0
0
L
L
L
L
Activated
Carbon
275
547
-
0.25
2.0
21.3
19.0
0.25
3.8
0.60
0
0.05
104
956
36.8
325
• Sorbent Capacities are expressed In »g of Ion removal per g of sorbent used.
- Indicates data not obtained for specific sorbent.
**L Represents no sorbent capacity and a reduction 1n leaching of contaminant when sorbent is mixed with leachate.
-------
In Table 4 a comparison of the magnitude of the micrograms of consti-
tuents removed per gram of sorbent used between the various sorbents indicates
which sorbents are the most effective for removing a specific constituent.
Chromium, iron, lead, and zinc are omitted from this table because their con-
centrations in the leachate are not significantly greater than the minimum
detectable value. There is no single sorbent material which is effective in
removing all measured parameters. However, either a combination of the
natural sorbents basic fly ash, kaolinite, vermiculite, and illite or the re-
fined sorbents, activated alumina and activated carbon, can be used to treat
all the measurable ions found in the calcium fluoride sludges provided that
leaching of ions from the sorbents does not exceed the sorbent's capacity for
removing these ions. The natural sorbents, basic fly ash and illite, exhibit
leaching of specific ions in the presence of water which may reduce the effec-
tiveness of these sorbents for treating the calcium fluoride sludge leachate.
The basic fly ash leaches significant amounts of calcium whereas the illite
leaches significant amounts of copper and magnesium ions (see Tables 1, 2, and
3). However, this leaching is reduced when these sorbents are placed in con-
tact with the slightly alkaline leachate. This is indicated by the effluent
concentration of the above ions being significantly less than the concentra-
tion level that is defined by the mathematic sum of the concentration of the
ion in the leachate and the background of sorbent material. These were ob-
tained with leachates that contained magnesium ion concentrations of 5.0 mg/1,
11.0 mg/1 and 21.3 mg/1.
The above reason however doesn't explain the results where significant
sorbent capacities are obtained for the removal of a specific ion in one or
two leachates but not in the third leachate. The calcium ion concentration in
all three fluoride leachates is above 300 ppm (see Tables 1, 2, and 3).
Yet, the illite exhibits significant sorbent capacities for calcium in lea-
chate #1 and leachate #2 but no sorbent capacity for calcium in leachate #3.
The reason for these results is not clear at the present time. However, re-
moval capacities may be highly pH dependent, and a slight difference in the
leachate pH will give different results. That is, the pH of leachates #1 and
#2 was 7.5, and that of #3 was 7.2.
Of the natural sorbents, illite was found to be the most effective for
fluoride, chloride, cyanide, and organic removal. Among the refined sorbents.
activated alumina was best able to reduce fluoride levels. Calcium and copper
removal was best accomplished with activated alumina. Regarding the natural
sorbents, kaolinite could be used for calcium and basic fly ash for copper
removal. Basic fly ash and activated alumina were the most effective for mag-
nesium and nickel removal. Vermiculite was the most effective for removing
cadmium.
Marked variations in the sorbent capacity for the removal from the three
leachates of specific contaminants can be observed in Table 4. One of the
possible reasons is that the sorbent capacity was determined using a constant
ratio of leachate to sorbent. The concentration of some of the contaminants
in the leachate using this ratio may not have been sufficient to saturate the
sorbent. As a result, the magnitude of these capacities could increase with
the concentration of the contaminant in the leachate being examined. For
example, the sorbent capacities exhibited by the basic fly ash for the magne-
26
-------
slum ion in the three leachates are 25.0, 4.3, and 43.3.
Metal Finishing Sludge Leachate
Analysis of the leachate prepared from the three metal finishing sludges
collected over a period of a year showed much greater variations in particular
contaminant concentrations than those encountered with the calcium fluoride
sludge leachate. Here, the concentration in some cases varied by at least a
factor of six when a specific constituent within the three leachates was com-
pared. For example, the calcium concentration ranged from 6.5 mg/1 to 38 mg/1
(see Tables 5 to 7).
The analysis of the metal finishing sludge leachates indicated the pre-
sence of significant concentrations of calcium, copper, magnesium, nickel,
fluoride, chloride, as well as organics (see Tables 5 to 7). The concentra-
tions of chromium, cadmium, iron, lead, cyanide, and zinc did not differ sig-
nificantly from the minimum measurable levels that can be determined using the
atomic absorption spectrometer and specific ion probes.
The sorbent capacity of the eleven natural and refined sorbents, with
respect to each of the measurable constituents in the leachate, is represented
in Tables 5 to 7. The sorbent capacities for the natural zeolites, the syn-
thetic activated alumina II and cullite were again evaluated using only the
metal finishing sludge leachate #1 and leachate #2. The sorbent capacities
for acidic fly ash and activated carbon were determined using leachate #3.
The sorbent capacities were obtained according to the calculations described
earlier.
A comparison of the sorbent capacities (see Table 8) indicates the most
effective sorbent material for removing specific constituents. Cadmium,
chromium, iron, lead, and zinc were omitted from this table because their con-
centrations in the leachate were at levels that could not be measured. The
natural sorbent, illite, was found to exhibit the largest sorbent capacity for
the oraanics and fluoride ion. Kaolinite exhibited the largest caoacity for
calcium; vermiculite for magnesium, nickel and copper. Vermiculite and illite
exhibited a capacity for chloride removal.
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 lea-
chates examined. However, a combination of vermiculite, illite and kaolinite
shows promise for treating the metal finishing sludge leachate provided that
the leaching of ions from one of the sorbents does not exceed the other sor-
bent 's capacity for removing these ions. The vermiculite exhibits the best
capacity for magnesium, copper, and nickel; kaolinite for calcium; illite and
vermiculite for the organics and chloride; and illite for fluoride.
A significant reduction in the copper leaching from illite, as was the
case for the fluoride sludge leachate, was only observed for leachate #3 (see
Table 7). The lack of this reduction in copper when the illite was mixed
with leachate #1 and leachate #2 is not understood at the present time.
27
-------
TABLE 5 : STATIC STUDY RESULTS OF METAL FINISHING SLUDGE LEACHATE II
ro
oo
Initial
Condition
Measured of Bottom
Parameters Leachate Description* Ash
pH 8.9
Conductivity 1200
•
Ca (mg/1) 6.5
Cd (mg/1) <0.01
Cr (mg/1) <0.20
2
{
1
2
3
t
2
3
i
Cu (mg/1) O.K J2
Fe (mg/1) <0.05
Mg (ng/1) 18.0
N< (mg/1) 0.15
Pb (mg/1) <0.20
Zn (mg/1) <0.01
F" (mg/1) 1.2
Cl" (mg/1) 125
CN" (mg/1) <0.03
COD (mg/1) 97.0
TOC (ng/1) 39.9
1
2
3
1
2
3
(1
2
3
1
2
3
1
2
3
2
3
2
3
1
3
2^
1
I
7.2
8.7
2780
3750
20.0
22.0
L**
<0.01
0.02
0
-------
TABLE 6 : STATIC STUDY RESULTS OF METAL FINISHING SLUDGE LEACHATE 12
ro
Measured
Parameters
PH
Initial
Condition
of Bottom
Leachate Description* Ash
8.8
Conductivity 1670
Ca (fig/1)
Cd (mg/1)
Cr (ng/1)
Cu (rng/1}
Fe (mg/1)
Hg (mg/D
Hi (ng/1)
Pb (ng/1)
Zn (mg/1)
r ("9/1 )
Cr (mg/l)
Of (rag/1)
COD (mg/1)
TOC (mg/1)
13.5
<0.01
0.25
(
0.05 (.
<0.05 (<
20.0 i
0.12 2
C
1
<0.20 i
C
(i
0.28
i) 0
<0.05
! <0.05
i
93. Z
' 46.0
! L
<0.05
• 0.15
1 0
) 0.13
0.07
0.07
0
<0.05
<0.05
169
54.0
L
<0.05
0.16
0
O.ZS
0.28
0
0.03
0.03
0
0.51
1.9
0
126
425
L
0.04
<0.03
26. ft
127
688
0
53.2
260
Vernlcullte
8.1
8.6
182
1360
1.5
8.0
55.0
<0.01
<0.01
<0.20
<0.20
0.50
<0.03
<0.03
0.20
<0.05
<0.05
4.7
15.0
50.0
<0.05
0.08
0.40
-------
TABLE 7 : STATIC STUDY RESULTS OF METAL FINISHING SLUDGE LEACHATE 13
OJ
o
Measured
Parameters
pH
Conductivity
Ca (mg/1)
Cd (rcg/1)
Cr (mg/1)
Cu (mg/1)
Fe (mg/1)
Mg (mg/1)
Ni (mg/1)
Pb (mg/1)
Zn (mg/1)
r (mg/1)
el' (mg/1)
CN' (mg/1)
COD (mg/1)
TOC (mg/1)
Initial**
Condition
of Bottom
Leachate Description* Ash
8.2
1140
38.1
<0.01
<0.20
0.53
<0.05
{
2
•1
7.2
7.5
2780
3800
20.0
30.5
19.0
<0.01
<0.01
<0.20
<0.20
T} 0.25
2) 0.39
3) 0.35
U> INJ — «
(1
25.5 (?
(3
0.19 (2
b
<0.05
<0.05
93.2
95.8
L
0.20
0.25
L
(1) <0.20
<0.20 (Z) <0.20
(3)
(1) <0.01
0.06 (2) 0.10
(3) L
1.5
95.0
2
3
<0.03 (2
(3
49.8
0.31
0.90
1.4
500
575
0
0.07
0.05
0
1) 40.3
2) 70.9
3) 0
(1) 0
19.7 (2) 19.5
(3) 0
Fly
Ash
(Acidic)
5.1
6.6
3150
4580
357
446
0 •
<0.01
<0.01
0.50
<0.20
0.29
0.13
1.0
<0.05
<0.05
64.4
15.3
25.5
1.4
1.4
0
0.30
0.30
0
1.6
1.4
L
1.7
1.6
L
' 10.0
75.0
50.0
' 0.04
0.04
0
<2.0
19.8
75.0
0.50
6.6
32.8
Fly
Ash
(Basic)
10.1
8.9
2090
2600
300 "
472
0
<0.01
<0.01
0.50
<0.20
0.06
0.16
0.93
<0.05
<0.05
3.2
2.2
58.3
<0.05
0.10
0.23
0.28
<0.20
<0.01
<0.01
0.13
1.1
1.1
0.88
9.5
57.5
93.8
<0.03
<0.03
4.8
26.4
58.5
4.1
12.0
19.3
Vermtcullte
9.3
8.4
115
1075
1.5
16.3
273
<0.0l
<0.01
0.13
2.1
1.0
1.2
4G.O
79.9
37.8
0.22
0.30
0
24.0
63.2
L
37.6
39.3
0
Activated
Carbon
9.4
9.0
575
1125
o;so
6.5
79.0
<0.01
<0.01
<0.20
<0.20
<0.03
<0.03
1.3
<0.05
<0.05
0.10
2.1
58.5
<0.05
0.10
0.23
<0.20
<0.20
<0.01
<0.01
0.13
' 0.04
1.6
0
5.0
75.9
47.8
<0.03
<0.03
<2.0
3.9
115.0
5.1
4.4
38.3
Minimum
Detectable
Value
-
-
0.10
0.01
0.20
0.03
0.05
0.05
0.05
0.20
0.01
0.02
2.0
0.03
2.0
-
1) Background of Sorbtnt Material (mg/1)
2) Effluent Level After Treatment (mg/1)
3) Sorbent Capacity ug Removed per g of
L Represents no Sorbent Capacity and a
Sorbent used.
Reduction In Leaching of Contaminant when
Sorbent 1s mixed with Leachate.
-------
TABLE 8 : COMPARISONS OF SORBENT CAPACITIES IN STATIC AND LYSINETER TESTS
(HETAL FINISHING SLUDGE LEACHATE)
Measured
Parameters Destriotion*
Ca
Cu
Hg
HI
F'
cr
coo
TOC
Static Test *1
Static Test 12
Static Test 13
Lysi meter Test
Static Test 11
Static Test «
Static Test »3
Lysineter Test
Static Test
-------
Petroleum Sludge Leachate
Analyses of the leachates prepared from the tank bottom sludge and the
A.P.I, gravity separator sludge indicated significant concentrations of cal-
cium, copper, iron, magnesium, nickel, zinc, fluoride, chloride, cyanide, and
organics (see Tables 9 and 10). However, marked differences in the concentra-
tions of constituents in each leachate were observed. The leachate prepared
from the tank bottom sludge contained a greater number of constituents of
higher concentration levels than those present in the A.P.I, separator sludge
leachate. For example, the organics in the tank bottom sludge leachate are
some four times higher than found in the separator sludge leachate. The cya-
nide concentration in the bottom sludge leachate is 40 times higher than in
the separator sludge leachate. Also, the tank bottom sludge leachate contain-
ed significant levels of iron and nickel whereas the levels of these metals in
the separator sludge leachate were not significantly higher than the minimum
detectable values observed using the atomic absorption spectrometer and the
specific ion probes.
The sorbent capacities exhibited by eleven sorbents for the removal of
constituents in the leachate is represented in Tables 9 and 10. The sorbent
capacities of the zeolite, cullite, and activated alumina II were determined
with the tank bottom sludge leachate. The acidic fly ash capacity was only
determined with the A.P.I, sludge leachate because we depleted our supply of
the tank bottom sludge leachate.
The sorbent capacities are listed in Table 11. Here, a comparison of the
sorbent capacities indicates the most effective sorbent for removing a speci-
fic constituent. Cadmium and chromium were omitted because their concentra-
tion levels in the leachate were not significantly different from the minimum
measurable concentrations.
In the natural sorbent category, illite appears to be effective for re-
moving magnesium and fluoride. Illite and vermiculite are effective for
chloride and the organics. Vermiculite is more effective than illite for re-
moving the cyanide ion in the tank bottom leachate but the reverse is true for
the A.P.I, sludge leachate where the cyanide ion concentration is lower. Il-
lite exhibits a greater sorbent capacity than the kaolinite for the calcium in
the tank bottom sludge leachate where high leachate concentrations of calcium
are encountered (see Table 9). On the other hand, kaolinite exhibits a grea-
ter sorbent capacity for the calcium in the A.P.I, sludge leachate where the
calcium leachate concentration is significantly lower. Activated carbon is
the best sorbent in the refined category for the removal of the chloride, cya-
nide, fluoride, and organics. Vermiculite exhibits the best sorbent capaci-
ties for copper in the A.P.I, sludge leachate, iron in the tank bottom sludge
leachate, and zinc in both leachates. Basic fly ash exhibits a capacity for
nickel for both leachates. Thus, combination of basic fly ash, kaolinite,
vermiculite, and illite shows promise for treating the constituents present in
both petroleum sludge leachates provided that the leaching of ions from one
sorbent does not exceed the other sorbent's capacity for removing these ions.
For the case of the refined sorbents, activated alumina and activated carbon
show promise for treating both leachates.
32
-------
TABLE 9 : STATIC STUDY RESULTS OF TANK BOTTOM PETROLEUM SLUDGE LEACHATE
co
CO
Measured
Parameters
pH
Initial
Condition Fly
of Bottom Ash
Leachate Description* Ash (Basic) Zeolite
7.4
Conductivity 15000
Ca (mg/1)
Cd (mg/1)
Cr (mg/1)
Cu (aig/l)
Fe (mg/1)
Hg (mg/1)
N1 (mg/1)
Pb (mg/1)
Zn (mg/1)
327
0.05
0.22
0.09
0.20
400
0.23
0.48
0.06
F" (mg/1) 1.5
CT (ng/1)
Of (mg/1)
COO
TOC
10990
7.9
1299
(
448
1
2
[
1
3
1
2
3
I
1
2
3
1
I
2
3
1
*
i
2
3
i
2
i
2
3
1
1
2
3
t—
-------
TABLE 10 : STATIC STUDY RESULTS FOR API SEPARATOR PETROLEUM SLUDGE LEACHATE
Measured
Parameters
P«
Conductivity
Ca (pig/1)
Cd (rag/1)
Cr (mg/1)
Cu (mg/1)
Fe (mg/1)
Kg (mg/1)
N1 (mg/1)
Pb (mg/1)
Z.i (mg/1)
F" (rag/1)
Cl* (mg/1)
CN" (mg/1)
COD (ng/1)
TOO («ig/l)
Initial
Condition
of Bottom
Leachate Description* Ash
ii J3
|i
(I
50.0 (2
(3
27SO
230
20.0
102
) 0
' — hr • *0.35
<0.05
<0.05
93.2'
71.4
L
...... .. fl_M
0.20
L
(i)
-------
CO
en
TABLE 11 : COMPARISONS OF SORBENT CAPACITIES III STATIC AND LYSIMETER TESTS
(PETROLEUM SLUDGE LEACHATE)
Measured
Parameters
Ca
Cu
Fe
«g
Ni
Zn
f
cr
or
COO
TCC
Description*
Static Test *1
Static Test 12
Lyslmeter Test
Static Test 11
Static Test i2
Lysimater Test
Static Test 11
Static Test #2
Lysimeter Test
Static Test tl
Static Test *2
Lyslmeter Test
Static Test #1
Static Test 12
Lyslireter Test
Static Test *1
Static Test 12
Lyslmeter Test
Statfc Test #1
Slatic Test *2
Lysimeter Test
Static Test fl
Static Test *2
Lysimeter Test
Statvc Test *1
Static Test 12
Lysimeter Test
Static Test i\
Static Test *2
Lysimeter Test
Static Test #1
Static Test 12
Lysimeter Test
Bottom
Ash
0
0
157
L
0.35
0.04
0.15
L
L
0
0
L
0.08
0.30
0.23
1.3
0.90
0
1C630
L
12.5
0.33
0
"628
588
495
208
224
219
Fly
Ash
(Acidic)
0
0
L
2.7
-
L
0
0
L
2.0
L
9.9
40.0
0.43
3.3
825
4545
318
1813
Fly
Ash
(Basic)
L
L
0
0
0.28
2.5
0.38
7.5
58.8
140
0.10
0.13
0.08
0.30
2.0
0.50
0.25
7.2
11980
75.0
7.5
0.35
3.3
1 628
712
5125
225 '
273
983
Zeolite
0
0
0
110
0
0.05
1.3
10630
12.3
703
175
Vermiculite
0
0
1010
0
1.8
1.6
1.0
100
0
90.0
0.20
0
0.30
1.5
6.4
1.0
L
0
49600
313
45.0
1.8
13.0
2850
2900
12555
810
1124
4995
Illite
415
0
1110
0.15
0.
0
0
0
70.0
25.6
180
0
L
0
L
0
3.Z
10.1
12.1
19780
1750
16.3
2.1
15.5
"1628
3526
5525
618
1325
2620
Kaollnite
300
100
14.0
0.15
L
0
0
37.5
18.8
753
0
0.25
L
1.5
o •
3.3
L
4.3
17280
350
6.5
0
4.2
465
3200
795
213
1240
273
Activated
Alumina
(I)
812
125
200
0.15
0.28
0.39
0.38
995
68.0
107
0.25
0.13
0.10
0.30-
0.43
2.7
L
3.4
11530
15.0
6.5
0
0
575
308
556
253
125
248
Activated
Alumina
(ID
811
0.15
0.38
995
0.23
0.05
1.9
11630
4.8
448
189
Cull He
765
L
0
903
0.03
0.05
1.6
13730
1.8
420
108
Activated
Carbon
723
92.8
160
0.08
0.23
0
0.38
468
43.8
10.0
0.15
0.13
0.10
0.30
1.3
3.3
0.50
1.3
20490
288
19.0
0.43
2.9
2985
753
300J
1055
289
1270
* Sorbsnt Capacities are expressed In g of Ion removal per g of sorbent used.
Indicates data not obtained for specific sorbent.
**L Represents no sorbent capacity and a reduction 1n leaching of contaminant when sorbent Is nixed with Leachate.
-------
DISCUSSION OF STATIC RESULTS
The results of the static tests on the three types of leachates (i.e.,
calcium fluoride, metal finishing, and petroleum) indicate that constituents
present in these leachates in some cases can be removed by the same sorbent,
and in other cases, different sorbents must be used to remove the same consti-
tuent in the leachate. The fluoride, chloride, cyanide, and organics in all
three types of leachate can be treated with illite. Vermiculite exhibits re-
moval capacities for the copper in the metal finishing sludge leachate and
petroleum sludge leachate whereas basic fly ash exhibits the highest capacity
for copper ion in the fluoride sludge leachate. Magnesium in the calcium
fluoride sludge leachate can be best treated with basic fly ash. In the
petroleum sludge leachate, illite is the most effective for magnesium whereas
vermiculite is most effective in treating the magnesium in two of the three
metal finishing sludge leachates. Calcium in the fluoride and metal finishing
sludge leachates can be treated with kaolinite. On the other hand, the illite
is more effective than the kaolinite in removing the calcium ion in the tank
bottom sludge leachate. Nickel, in the fluoride sludge leachate and petroleum
sludge leachate, may be treated with basic fly ash and in the metal finishing
sludge leachate, with vermiculite.
The reason for the above differences in behavior of the sorbents toward
the same constituents in different leachates is not known at this time. How-
ever, it is believed that the effectiveness of a specific sorbent for removal
of a contaminant may be influenced by the other contaminants present in the
leachate because of competition for available sorbent sites. Thus, some of
the constituents may tend to bind more readily to the active sites on the sor-
bents than others.
RESULTS OF THE LYSIMETER STUDIES
As a result of the static studies using the leachates prepared from the
three industrial sludges, the natural sorbents (i.e., basic fly ash, vermicu-
lite, illite, kaolinite) and the refined sorbents (i.e., activated alumina and
activated carbon) showed the most promise for treating the constituents found
in the three leachates. Although bottom ash and acidic fly ash were not as
effective in the static studies, they are also included in the lysimeter stu-
dies because preliminary examinations under flowing conditions indicate a
greater removal than under static conditions.
The vermiculite, illite, and kaolinite used in these lysimeter studies
consisted of a mixture of 20 percent sorbent and 80 percent inert Ottawa sand
because the permeability exhibited by the "pure" sorbents was so low that
virtually no flow was obtained. The results of a series of permeability stu-
dies using different mixtures of sand and clay indicated that the above clay-
sand mixture would provide the minimum flow of leachate through the solids
that could be measured within a reasonable time.
In these lysimeter studies, only the leachates prepared from the calcium
fluoride sludge #3, metal finishing sludge #3, and the petroleum sludge from
the gravity separatory were used. There was not enough of the calcium fluo-
ride sludges #1 and #2, metal finishing sludges #1 and #2 and the petroleum
36
-------
tank bottom sludge remaining after the static studies to permit the prepara-
tion of the 50 gallons of each leachate required for the lysimeter studies.
In view of the large number of measurements required for the lysimeter
studies, the analyses for the constituents in the effluent from the lysimeter
were performed only on those constituents whose concentrations were signifi-
cantly higher than the minimum measurable concentration or exceeded the ac-
ceptable concentration for raw water standards (18). The analysis for the
calcium, copper, magnesium, fluoride, and organics were carried out with the
calcium fluoride sludge leachate. Cadmium, chromium, iron, and lead were ex-
cluded because the concentrations in leachate #3 were below the measurable
levels (see Table 3). Both zinc and chloride were not determined because
their concentrations in the leachate were below raw water standards.
The analysis for calcium, copper, magnesium, nickel, fluoride, and the
organics were performed on the metal finishing sludge leachate #3. The cad-
mium, chromium, iron, lead, and cyanide were excluded because their concentra-
tions were below measurable levels (see Table 7). Both zinc and chloride were
below raw water standards.
The analysis for the calcium, copper, magnesium, zinc, fluoride, cyanide,
and the organics were performed on the A.P.I, separatory sludge leachate. The
cadmium, chromium, and iron were excluded because their concentrations were
below measurable levels (see Table 11). Chloride was excluded because its
concentration was below raw water standards.
Calcium Fluoride Sludge #3 Leachate
The effectiveness of selected sorbents for removing calcium, magnesium,
copper, fluoride, and the organics under flowing conditions was determined by
measuring the concentration of these constituents in the leachate before and
after it had been percolated through the sorbent. The pH of the leachate
before and after it passed through the sorbent was also monitored. The re-
sults are represented in Figures 3 through 9. Here, the concentration of the
constituent remaining in a sample collected, after a known volume of leachate
was passed through the column, is plotted against this volume of leachate.
The background of the sorbents were not evaluated using water under flowing
conditions because leaching from the sorbent was indicated when the effluent
concentration exceeded the influent leachate concentration of a particular
contaminant.
The pH of the specific leachate samples collected from the lysimeter
changed as leachate is passed through the columns (see Figure 3). The pH
values of the effluent leachate collected initially are defined by the pH of
the sorbent. For example, the pH of the leachate sample collected initially
from the illite-sand mixture is 3. This sorbent, when mixed with water, ex-
hibits a background pH of 3 (see Table 3). However, after 4 liters of lea-
chate were passed through the sorbent, the pH of the effluent approached that
of the leachate. This is observed for all the sorbents studied.
Calcium Removal--
Kaolinite, activated alumina, activated carbon, illite, vermiculite, and
37
-------
11
u>
00
m
-h
-h
(D
3
•o 7
8
Leachate
O Activated Alumina
Activated Carbon
Q .Fly Ash (Acidic)
• *Fly Ash (Basic)
Q Illite
O Vermiculite
A Kaolinite
JL
Q Bottom Ash
16
Effluent Volume, liters
24
32
Figure 3. Lysimeter Studies of pH in Calcium Fluoride Sludge Leachate.
-------
acidic fly ash were examined in the lysimeter for their ability to remove cal-
cium under dynamic conditions. Leachate was passed through these columns un-
til the concentration of calcium in the sample effluent leachate approached
that of the influent leachate or excessively low permeability was encountered.
The results indicate that activated alumina is the most effective for
treating the calcium in the calcium fluoride sludge #3 leachate up to the
addition of 29 liters of leachate (see Figure 4). Beyond this point, the per-
meability of the activated alumina became excessively low (see Figure 10).
For the inexpensive sorbents, kaolinite-sand mixture is the most effective
with break-through occurring after 10 liters of leachate had been passed
through this sorbent.
The sorbent capacities that are exhibited by each sorbent for a specific
contaminant in the calcium fluoride sludge leachate #3 were determined from
the curves in Figure 4. The area under each lysimeter curve, which also in-
cludes that portion where (in some cases) the concentration of contaminant
exceeds that in the influent, was integrated and multiplied by the total vol-
ume of effluent collected until break-through was achieved or the permeability
exhibited by the sorbent became excessively low. (Break-through is defined
as the point where the concentrations of a specific contaminant in the influent
and effluent leachates are comparable and there is no longer any significant
removal of a specific contaminant by the sorbent.) This provides the total
amount of contaminant added to the lysimeterj the result is equal to the total
amount of contaminant removed by the sorbent. This latter value is determined
by multiplying the concentration of the contaminant in the influent leachate
by the volume of leachate used. The sorbent capacity is determined by divi-
ding the total amount of contaminant removed by the amount of sorbent used in
the lysimeter.
The sorbent capacities for activated alumina, activated carbon,
acidic fly ash, illite, vermiculite and kaolinite are presented in Table 4.
Here, it is shown that activated alumina exhibits the largest capacity follow-
ed by kaolinite, illite, and then activated carbon.
A comparison of the sorbent capacities exhibited by the acidic fly ash
and illite under static and dynamic condition reveals that calcium is only
removed from the leachate under flowing conditions. These results are proba-
bly due to the greater increase in pH that occurs as the slightly alkaline
leachate flows through these sorbents than is achieved under static conditions.
The initial fraction of leachate effluent collected shows that calcium is
being leached from both sorbents (see Figure 4). The pH of the acidic fly ash
and illite effluents collected initially are 5 and 3.2 respectively (see
Figure 3) and are comparable or slightly more acidic than the pH of those
effluents collected under static conditions (see Table 3). The analysis of
the next effluent fraction collected from the acidic fly ash and illite lysi-
meters show removal of the calcium ion from both leachates. The pH of these
fractions are 6.0 and 3.8 respectively.
There are significant variations in the concentration of calcium ion in
the initial effluent fractions collected from the lysimeters containing the
39
-------
n>
o
o
o
n>
01
o>
300
200
100
O
A
9
o
o
A
Leachate
Activated Alumina
Activated Carbon
Fly Ash (Acidic)
Illite
Vermiculite
Kaolin!te
12 16
Effluent Volume, liters
20
Figure 4. Lysimeter Studies of Calcium Ion in Calcium Fluoride Sludge Leachate.
-------
different sorbents. This is presumably due to the different amounts of cal-
cium leached from the various sorbents.
Copper Removal--
The sorbents which are effective for removing copper, based on the static
results, from the calcium fluoride sludge #3 leachate are basic fly ash, acti-
vated alumina, and activated carbon. Their removal capacities were 0.10,
0.15, and 0.25 micrograms removed per gram of sorbent used, respectively (see
Table 4). Thus, these sorbents were examined for removal of the copper under
flowing conditions. The kaolinite, vermiculite, and acidic fly ash were also
examined.
The effective sorbents for the treatment of copper were found to be aci-
dic fly ash, activated alumina, activated carbon, and kaolinite (see Figure
5). The vermiculite-sand mixture showed no removal of copper under flowing
conditions. Acidic fly ash and kaolinite-sand mixture were found to be ef-
fective for copper treatment under flowing conditions even though their static
tests showed no sorbent capacity for copper. pH may be a factor, in both
cases. As leachate is added to the acidic fly ash in the lysimeter, the pH is
raised from 4 to slightly above 7 after 4 liters have passed through the col-
umn (see Figure 3). When the effluent leachate becomes slightly alkaline, the
copper is removed. The concentration of copper in the effluent leachate now
falls below the dotted line which represents the initial concentration of
copper in the untreated leachate. For the case of the kaolinite the pH of the
initial kaolinite effluent collected is significantly more alkaline than the
pH of the kaolinite effluent obtained under static conditions. The pH of this
effluent remains relatively constant at slightly greater than 6 and becomes
neutral when break-through occurs (see Figure 5).
Considerable variations of the copper ion concentration is observed in
the initial fractions of effluent collected from the different lysimeters.
This is probably due to the different amounts of copper that are leached from
the various sorbents. In fact, the concentration of copper in the first 0.09
liters of effluent collected from the acidic fly ash is 2.5 mg/1. This is far
in excess of the background concentration of 0.06 mg/1 obtained in the static
studies (see Table 3).
These excessive concentrations, when'compared to the static data, occur
because the leachate to sorbent ratio for the initial effluent collected from
the lysimeters is equivalent to only 0.2 to 1, as opposed to the water to sor-
bent ratios of 2.5 to 1 used for the determination of background of sorbent
material in the static studies.
These results indicate that the maximum amount of copper that can be lea-
ched from the acidic fly ash was not achieved (as defined by the conductance
measurements) using the water to sorbent ratio of 2.5 to 1 or that the lower
pH of 4.2 exhibited by this effluent fraction resulted in greater leaching of
the copper than had occurred in the static studies -where a pH of 5.4 was en-
countered.
The sorbent capacities for the removal of copper by the acidic fly ash, kao-
linite-sand mixture, activated alumina and activated carbon are 2.2, 8.9, 2.9,
41
-------
-p.
ro
m
-h
-h
n>
rt-
o
o
3
O
H-
QJ
O
3
O
-h
O
£Z
u
ua
0,10
0.05
(2.5 mg/1, at 0.09 1)
(0.28 ng/1, at 0.08 1)
Leachate
Activated Alumina
Activated Carbon
Fly Ash (Acidic)
Fly Ash (Basic)
Vermlculite
KaolJnlte
12 16
Effluent Volume, liters
20
Figure 5. Lysimeter Studies of Copper Ion in Calcium Fluoride Sludge Leachate.
-------
and 2.0 micrograms of copper removed per gram of sorbent used. The sorbent
capacity for the kaolinite-sand mixture is significantly greater than the
other sorbents, even though it is not apparent from a comparison of the curves
in Figure 5 because the amount of kaolinite used in the lysimeter is only 20
percent of the weight of the other sorbents used.
The kaolinite-sand coefficient of permeability shows a significant de-
crease with the addition of leachate to the lysimeter. However, this levels
off at the point of copper break-through (see Figure 10). This reduction in
coefficient of permeability for the kaolinite-sand mixture is not as signifi-
cant a problem as would occur if the next best sorbent, activated alumina,
were used. The coefficient of permeability for the activated alumina shows no
leveling off. Thus, a point could be reached where the activated alumina
could form an impermeable barrier.
Magnesium Removal —
Acidic and basic fly ash, activated alumina, and activated carbon were
examined for removing the magnesium from the leachate under flowing conditions.
The results indicate that basic fly ash and activated alumina are effective
sorbents for treating the magnesium in the leachate (see Figure 6). Acidic
fly ash was found to be effective for removing the magnesium after the pH of
the leachate became alkaline. This occurs after approximately 2 liters of
leachate has been passed through this sorbent. Prior to this, magnesium was
continuously leached from acidic fly ash. Thus, basic fly ash should be used
with the acidic fly ash in a layered system to remove the magnesium during
this initial leaching period.
The activated alumina appears to exhibit the greatest capacity for remov-
al of magnesium ion and is capable of handling the largest volume of leachate
(30 liters). Beyond this, its permeability becomes excessively low.
The sorbent capacities for acidic and basic fly ashes, activated alumina,
and activated carbon were determined to be 250, 172, 534, and 19 micrograms of
magnesium removed per gram of sorbent used. This order of effectiveness for
removing the magnesium ion is also apparent from the lysimeter curves (see
Figure 6) since all the lysimeters contain 100% of the sorbent.
Fluoride Removal~
The effectiveness of acidic and basic fly ashes, bottom ash, illite, ver-
miculite, kaolinite, activated alumina, and activated carbon were investigated
for the treatment of fluoride sludge #3 leachate. The results show that the
refined sorbent, activated alumina, is the most effective for removing the
fluoride (see Figure 7) even after 26 liters of leachate was added to the
lysimeter. Acidic fly ash appears to be the most effective natural sorbent
for fluoride removal. The illite-sand mixture and bottom ash exhibit similar
types of removal curves. Both vermiculite and activated carbon are least
effective.
The sorbent capacities for the bottom ash, acidic and basic fly ashes,
vermiculite-sand mixture, illite-sand mixture, kaolinite-sand mixture, acti-
vated alumina, and activated carbon are listed in Table 4. Illite and acti-
vated alumina, which proved to be the most effective in treating fluoride
43
-------
25
20
-h
215
c
fD
3
ft-
O
O
O
n>
Ol
O
3
10
to
(59
[—
.5 mgjl,
T
at 0.19 1)
— Leachate
^ Activated Alumina
£ Activated Carbon
Q Fly Ash (Acidic)
A Fly Ash (Basic)
I
12 16 20
Effluent Volume, liters
24
28
32
Figure 6. Lysimeter Studies of Magnesium Ion in Calcium Fluoride Sludge Leachate.
-------
n>
O
O
o
o>
-x
Ol
0
Leachate
O Activated Alumina
A Activated Carbon
O Bottom Ash
® Fly Ash (Acidic)
• Fly Ash (Basic)
Illite
Vermiculite
D
O
A
Kaolinite
-ft
12 16
Effluent Volume, liters
20
Figure 7. Lysimeter Studies of Fluoride Ion in Calcium Fluoride Sludge Leachate
-------
under static conditions, also appear to be most effective under flowing condi-
tions. However, the basic fly ash and bottom ash, which appear to be more
effective than acidic fly ash for fluoride treatment under static conditions,
are not as effective under flowing conditions.
The removal of fluoride under flowing conditions appears to be favored by
acidic conditions. The acidic fly ash exhibits significantly better removal
than either the bottom ash or basic fly ash when acidic conditions are encoun-
tered during the initial 4 liters of effluent collected. As the effluent be-
comes basic, the removal of fluoride by the acidic fly ash decreases (see
Figure 7). In the case of the illite-sand mixture and kaolinite-sand mixture,
the fluoride is removed until their effluents become basic. At this point, no
removal of the fluoride is observed for both sorbents.
Considerable variation was observed in the amount of leachate influent
passed through the sorbents before break-through occurred. Activated alumina
again appeared to be able to handle large volumes of leachate before fluoride
break-through occurred (see Figure 7). Fluoride break-through for the acidic
fly ash did not occur until approximately 12 liters of leachate had been
passed through this sorbent. The kaolinite exhibited fluoride break-through
at 10 liters. Fluoride break-through for the illite-sand mixture and bottom
ash occurred at slightly above 4 liters.
Organic Removal--
Bottom ash, acidic and basic fly ashes, vermiculite-sand mixture, illite-
sand mixture, kaolinite-sand mixture, activated alumina, and activated carbon
were examined for their effectiveness in removing the organics under flowing
conditions. The results indicate that acidic fly ash and activated carbon are
the most effective sorbents for removing the organics in the calcium fluoride
sludge #3 leachate (see Figures 8 and 9). The performance of the activated
carbon was as expected since it is widely used for the removal of organics in
waste streams. The illite-sand mixture, however, which appears to be the most
effective under batch conditions (see Table 4) is not as effective as acidic
fly ash under flowing conditions even though account is taken of the fact that
the illite lysimeter contains only 20 percent illite. The removal capacity of
acidic fly ash for both COD and TOC is 704 and 156 micrograms removed per gram
of acidic fly ash used, respectively, as compared with the removal capacity of
illite for both COD and TOC of 250 and 80 micrograms removed per gram of il-
lite used, respectively.
Acidic conditions appear to be a factor in the removal of the organics
but the acidic fly ash is seen to be less dependent than the illite. Break-
through of organics for the illite is observed when its effluent becomes alka-
line but the acidic fly ash continues to remove the organics even though its
effluent is alkaline (see Figure 8).
The treatment of appreciable volumes of leachate before COD and TOC
break-through occurs can better be handled by the activated carbon than acidic
fly ash. The COD and TOC break-through for acidic fly ash occurs after 9
liters of calcium fluoride sludge #3 leachate was passed through the sorbent
(see Figures 8 and 9). For the case of the activated carbon sorbent, the flow
of leachate through this sorbent was stopped after 12 liters had been passed
46
-------
m
-*>
o>
o
o
O
a>
O»
O
=3
O
O
- Lcachate
A Activated Carbon
O Bottom Ash
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
A Kaolinite
Effluent Volume, liters
Figure 8. Lysimeter Studies af COD in Calcium Fluoride Sludge Leachate
-------
00
m
-h
o>
o
o
o
(D
Ol
rt-
o
-h
O
o
(£>
Leachate
Activated Carbon
Bottom Ash
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
Kaolinite
6 8
Effluent Volume, liters
10
12
14
Figure 9. Lysimeter Studies of TOC in Calcium Fluoride Sludge Leachate
-------
through. However, even at this point, effective removal of the organics con-
tinued to be observed.
Permeability Results--
The use of refined and natural sorbents for the removal of specific con-
stituents in the leachate of industrial sludge depends on the removal capaci-
ty of the sorbent for a constituent in the leachate. The sorbent should also
exhibit suitable permeabilities to handle hydraulic loadings without ponding
occurring at the bed surface. A series of constant head permeability tests
were performed on activated alumina, activated carbon, bottom ash, basic fly
ash, the illite-sand mixture (20 percent illite 80 percent Ottawa sand), and
vermiculite-sand mixture (20 percent vermiculite, 80 percent Ottawa sand)
using the calcium fluoride sludge #3 leachate in order to determine the per-
meability characteristics of these sorbents. Here the coefficient of permea-
bility versus leachate volume was determined for each sorbent until break-
through of organics from the illite-sand mixture occurred at about 5 liters
(see Figures 8 and 9).
The results indicate that the coefficient of permeability remains essen-
tially constant with effluent volume for the sorbents tested, with the excep-
tion of activated alumina and kaolinite (see Figure 10). The coefficient of
permeability for the activated alumina is reduced from an initial value of
7.7 x 10'4 cm per sec. to 2.1 x 10-5 cm per sec. at the completion of the
test (see Table 12). This amounts to approximately one-fortieth of its ini-
tial value but then appears to level off after break-through of contaminants
has occurred. Apparently, the removal of constituents from the leachate by
these sorbents results in a reduction in pore volume through which the leach-
ate flows. This does not appear to be the case for the other sorbents where
the coefficient of permeability remains fairly constant as the constituents
are removed from the leachate. Thus, although activated alumina is effective
in removing the cations from the calcium fluoride sludge #3 leachate under
flowing conditions (see Table 4), its presence in a bed for treatment of
leachate from calcium fluoride sludge over a period of time may lead to pond-
ing due to the marked reduction in its coefficient of permeability.
Summary of Results
In general, a comparison of the results of the batch tests with those
obtained with the lysimeter using the same calcium fluoride sludge #3 lea-
chate indicates that significantly greater removal capacities for given con-
stituent are obtained under flowing conditions than under static conditions
(see Table 4). For example, the fluoride sorbent capacity obtained for il-
lite under non-flowing conditions was 79.9 micrograms of fluoride removed per
gram of illite used as compared to 205 micrograms of fluoride removed under
flowing conditions. Also, in some cases, where the static test results show-
ed no sorbent capacity the lysimeter tests showed significant removals. The
sorbent capacity of acidic fly ash for magnesium under non-flowing conditions
was zero. Under flowing conditions, 250 micrograms of magnesium was removed
per gram of acidic fly ash used (see Table 4).
In some cases, the removal of calcium, copper, and magnesium by sorbents
49
-------
such as illite-sand mixtures and acidic fly ash appears favored by an increase
in pH to alkaline conditions. As the pH of their effluent is increased, the
cations that are leached from these sorbents at lower pH are removed at the
higher pH. In other cases alkaline conditions do not appear to favor the re-
moval of copper and magnesium by the basic fly ash, or calcium by the vermicu-
lite-sand mixture. Greater removals are achieved by these sorbents under
flowing conditions, even though the effluent collected from the lysimeters and
from the static test are both alkaline. The reasons for the latter observa-
tions are not known at this time. However, it is presumed that the selecti-
vity of specific sorbents for the removal of a constituent is influenced by
other constituents in the leachate. In the static tests, the more competitive
constituents could bind to the sorbent first and thus reduce the available
binding sites to the less competitive constituents. However, under flowing
conditions, the more competitive constituents may be primarily removed in the
top of the column. The less competitive ions may bind to the sorbents further
down the columns as a result of decrease in the concentration of the more com-
petitive constituents in the top of the column. The combined effects of pH,
ion exchange capacity and sorption capacity on the interaction between the
contaminants in the leachate and the sorbents are the areas that need further
study.
Metal Finishing Sludge #3 Leachate
The effectiveness of acidic and basic fly ashes, vermiculite, illite,
kaolinite, activated alumina, and activated carbon for removing calcium,
copper, magnesium, nickel, fluoride, and organics in the metal finishing
sludge #3 leachate, was examined under flowing conditions. The above consti-
tuents were selected because their concentrations in the leachate were at
levels that could be measured using the atomic absorption spectrophotometer or
specific ion probes. In addition, the pH, before and after the leachate
passed through the sorbents, was monitored to determine if pH has an effect
on the sorbent's ability to remove a specific constituent.
The results of this study are shown in Figures 11 to 18. The dotted
lines in each of these figures represent the concentration of the constituent
present in the metal finishing sludge #3 leachate prior to treatment with a
sorbent.
The pH of the effluent leachate samples collected from the lysimeter con-
taining the different sorbents again approaches (with the exception of activa-
ted alumina and kaolinite) upon the addition of leachate, the pH of the in-
fluent leachate (see Figure 11). It is presumed that if additional volumes
of leachate were added to the activated alumina and kaolinite, the pH of their
effluents would also approach that of the leachate. The collection of lea-
chate from the activated alumina was stopped after 10 liters because its per-
meability became excessively low (see Figure 20). The kaolinite was not taken
beyond 10 liters because break-through of calcium occurred at this point
(see Figure 12). After 4 liters of leachate was added to the sorbents,
the pH of the effluent metal finishing sludge leachate approached that of
the influent. Sixteen liters of leachate was required to reach this point
for the fluoride sludge leachate, however. The stronger alkalinity of the
metal finishing sludge #3 leachate (pH = 8.2) may be the reason for this
50
-------
10
u
OJ
CO
•o
c
O Activated Alumina
O Bottom Ash
O Fly Ash (Basic)
D Illite
O Vermiculite
^ KaoTinite
fc Fly Ash (Acidic)
l
10 20
Effluent Volume, liters
30
Figure 10. Permeability Studies of Sorbent Materials with Calcium Fluoride
Sludge Leachate
51
-------
10
-h
-b
CD
3
rt-
T3
— Leachate
O Activated Alumina
A Activated Carbon
O Fly Ash (Acidic)
C Fly Ash (Basic)
D Ulite
O Vertniculite
A Kaolinite
J_
12 16 20
Effluent Volume, liters
24
28
32
Figure 11. Lysimeter Studies of pH in Metal Finishing Sludge Leachate
-------
behavior. As a result, the pH of the effluent in all cases becomes alkaline
after a little less than 2 liters has passed through the sorbents.
Calcium Removal-
The removal of calcium from the metal finishing sludge #3 leachate by the
sorbents, under flowing conditions, is represented in Figure 12. Here, the
illite-sand mixture, vermiculite-sand mixture, kaolinite-sand mixture, and
activated alumina were shown to be effective sorbents for the removal of cal-
cium. The sorbent capacity exhibited by each of these sorbents is 1828, 1280,
930, and 737 micrograms of calcium removed per gram of sorbent used, respective-
ly (see Table 8). The sorbent capacity obtained for the activated alumina is
lower than the clay-sand mixtures even though it appears more effective (see
Figure 12). Calculation of this sorbent capacity is based on only 10 liters
of leachate being passed through this sorbent, as compared with 22 liters and
14 liters of leachate passed through the illite and vermiculite, respectively.
The flow of leachate through the activated alumina essentially stopped after
10 liters had been passed through this sorbent.
It should be noted that both acidic and basic fly ashes exhibit leaching
at leachate volumes below 2 liters (see Figure 12). After this, the calcium
is removed. The concentration of calcium in initial effluent fractions col-
lected from the fly ash lysimeters is greater than that obtained when the
acidic and basic fly ashes were mixed with water under static conditions (see
Table 7). The volumes of effluent collected from the acidic and basic fly
ash lysimeters is equivalent to leachate to sorbent ratios of 1.2 to 1 and 0.6
to 1, respectively. This is significantly lower than the water to sorbent
ratio of 2.5 to 1 used in the static studies to achieve maximum leachate con-
centrations as indicated by conductance measurements. Apparently, the larger
ratio did not provide a saturated concentration of Teachable calcium since the
concentrations of calcium in the initial effluent fraction collected from the
lysimeters is greater than that obtained in the background of sorbent mater-
ials determinations under static conditions.
Considerable variations are observed in the concentrations of calcium
present in the initial fractions of effluent collected from the lysimeters
(see Figure 12). This is presumed to be due to the different amounts of cal-
cium that may be leached from the sorbents as is apparent from the data for
background of sorbent materials obtained under static conditions (see Table
' / •
Greater sorbent capacities were obtained under flowing conditions than
under static conditions (see Table 8). In fact, no sorbent capacities were
obtained for the acidic and basic fly ashes and illite under static conditions,
but significant removals were obtained under flowing conditions.
The reason for this is not clear at this time. The pH does not appear to
be a factor, as was indicated earlier for the calcium fluoride sludge leachate
lysimeter results, since the initial fractions of effluent collected from the
acidic and basic fly ash lysimeters exhibit alkaline pH.
The illite-sand mixture appears capable of handling the greatest volume
of leachate before break-through of calcium occurs (see Figure 12). Activated
53
-------
TABLE 12 : PERMEABILITY CHARACTERISTICS OF SORBENT MATERIALS
SORBENT MATERIAL
cn
1. Illlte (20X) mixed with Ottawa Sand (SOX)
2. Vermlcullte (20X) nixed with
3. Fly Ash (Acidic)
4. Fly Ash (Basic)
5. Bottom Ash
6. Kaollnlte (20X) mixed with Ottawa Sand (80X)
7. Activated Alumina
8. Activated Carbon
1. Illlte (20!) mixed with Ottawa Sand (80X)
2. Vennicullte (20X) mixed with (
3. Fly Ash (Acidic)
4. Fly Ash (Basic)
5. Kaollnlte (20X) mixed with OH
6. Activated Alumina
7. Activated Carbon
1. Illlte (201) mixed with Ottawa Sand (BOX)
2. Vermlcullte (20X) mixed with (
3. Fly Ash (Addle)
4. Fly Ash (Basic)
5. Bottom Ash
6. Kaollnlte (20X) mixed with Ottawa Sand (SOX)
7. Activated Alumina
8. Activated Carbon
A.
fid (SOX)
rf» Sand (SOX)
Sand (80X)
B.
id (80X)
» Sand (80X)
Sand (80X)
C.
id (BOX)
(a Sand (BOX)
Sand (SOX)
e K} (Cm/sec)
Calcium Fluoride Sludqe Leachate
0.52
1.83
1.41
1.38
0.69
0.79
2.07
1.66
Metal Finishing
0.49
1.81
1.50
0.84
0.53
2.29
1.45
Petroleum Sludge
0.44
2.01
1.50
1.01
0.64
0.40
2.20
1.50
2.2
5.8
1.5
1.1
3.3
7.1
7.7
5.2
x
x
X
X
X
X
X
X
IO-5
io-5
io-4
ID'4
ID'4
ID'5
io-4
io-2
K^Cm/sec) K^l^ d10(«n.)
3.7 x
6.4 x
1.3x
9.9 x
3.8 x
2.1 x
2.1 x
6.4 X
ic-5
io-5
io-5
ID'5
io-5
ID'5
io-s
io-2
0.6
0.9
1.2
1.1
8.7
3.4
36.7
0.8
0
0
0
0
0
0
0
1
.016
.20
.0041
.010
.028
.028
.075
.1
Cu
37.5
3.0
2.0
1.4
6.4
21.4
1.3
1.8
Specific
Gravl ty,Gs
2.68
2.52
2.13
2.25
2.69
2.67
3.24
1.26
Sludge Leachate
9.2
1.4
2.1
9.4
2.5
1.4
7.2
X
X
X
x
x
X
X
ID'4
io-4
io-4
10'5
10"5
io-3
io-2
2.7 x
1.1 x
4.7 x
1.3x
1.2 x
4.5 x
8.6 x
io-4
ID'5
io-5
io-5
ID'5
ID'6
io-2
3.4
12.7
4.5
7.2
2.1
311.
0.84
0
0
0
0
0
0
1
.016
.20
.0041
.010
.028
.075
.1
37.5
3.0
2.0
1.4
21.4
1.3
1.8
2.68
2.52
2.13
2.25
2.67
3.24
1.26
Leachate
1.2
8.5
2.7
1.3
4.4
1.4
1.2
6.7
X
X
x
X
x
x
X
X
io-4
ID'5
10'4
ID'4
10
10
ID'3
ID'2
7.5 x
6.3 x
3.1 x
1.8 x
1.5 x
3.0 x
1.7 x
6.7 x
ID'5
io-5
io-4
ID'4
10'6
io-6
ID'6
ID"2
1.6
1.4
0.9
0.7
293.
4.7
706.
1.0
0
0
0
.016
.20
.0041
0.010
0.028
0.028
0.075
1.1
37.5
3.0
2.0
1.4
6.4
21.4
1.3
1.8
2.68
2.52
2.13
2.25
2.69
2.67
3.24
1.26
REMARKS: e "Void Ratio
K, - Initial Coefficient of Permeability
Kg • Terminal Coefficient of Permeability
d10(mm) •
Cu «
Grain Size Diameter at 10X finer
Coefficient of Uniformity
-------
m
-t>
-h
c
n>
F+
o
o
=3
O
n>
3
o
-h
O
(Q
40
35
30
25
20
15
10
—i—i—i—\—r—
(535 mg/1, at 0.6 1)
(344 mg/1, at 0.30 1)
-J
Leachate
O Activated Alumina
A Activated Carbon
O Fly Ash (Acidic)
Fly Ash (Basic)
Illite
Vermiculite
9
a
o
A
Kaolinite
OOKM—
-------
alumina would probably handle the greatest volume of leachate prior to break-
through if the samples of effluent leachate could be collected beyond the 10
liters of leachate that were passed through the activated alumina. This could
not be shown because the flow through this sorbent virtually stopped after 10
liters had been passed through the sorbent.
Copper Removal--
The removal of copper from the metal finishing sludge #3 leachate can be
achieved by the acidic fly ash, the illite-sand mixture, the vermiculite-sand
mixture, and activated carbon (see Figure 13). Although acidic fly ash ap-
pears to be more effective for removing the copper than the illite and vermi-
culite-sand mixtures, it must be remembered that the amount of vermiculite and
illite used in these tests is only 20 percent by weight of the acidic fly ash
used. If this is taken into account, the illite and vermiculite are then
found to exhibit sorbent capacities of 57.5 and 20.5 micrograms of copper re-
moved per gram of sorbent used, as compared with 16.5 micrograms of copper re-
moved per gram of the acidic fly ash (see Table 8).
No leaching of copper from the acidic fly ash is observed. The fact that
the pH of the effluent leachate from this sorbent is never acidic may be the
reason, when the effluent leachate is acidic, as was encountered with the
illite at volumes below 1 liter, copper is leached out of illite (see Figure
13).
An analysis of the sorbent capacity exhibited by the illite for copper
shows a significant removal capacity for copper under flowing conditions
but none under static conditions (see Table 8). Apparently, the fact that
the pH of the illite effluent was significantly acidic in the static studies
resulted in leaching rather than removal of the copper.
Activated carbon appears to be able to treat copper in the largest volume
of metal finishing sludge #3 leachate (see Figure 13). Acidic fly ash and the
illite-sand mixture appear to be next for treating large volumes of this lea-
chate.
Magnesium Removal--
The activated alumina, acidic fly ash, and illite-sand mixture appear
to be the most effective sorbents for the removal of magnesium and for hand-
ling the largest volumes of the metal finishing sludge #3 leachate before
break-through occurs (see Figure 14). The sorbent capacities for each of
these sorbents were 495, 488, and 1840 micrograms of magnesium removed per
gram of sorbent used, respectively (see Table 8).
No Teachable magnesium was observed with the acidic fly ash, as was en-
countered with fluoride leachate. This may be due to the fact that the pH of
acidic fly ash, even in the initial effluent fractions collected, remains
above 7.
Nickel Removal--
Activated carbon, acidic fly ash and activated alumina appear to be the
most effective in removing the nickel in the metal finishing sludge #3 lea-
56
-------
tn
Leachate
O Activated Alumina
A Activated Carbon
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
Vermiculite
8 12 16
Effluent Volume, liters
20
24
Figure 13. Lysimeter Studies of Copper Ion in Metal Finishing Sludge Leachate.
-------
tn
CO
Leachate
Activated Alumina
Activated Carbon
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
Vermiculite
12 16
Effluent Volume, liters
Figure 14. Lysimeter Studies of Magnesium Ion in Metal Finishing Sludge Leachate
-------
chate (see Figure 15). However, if account is taken of the fact that the
illite-sand mixture contains only 20 percent by weight of the activated carbon
and acidic fly ash used, then illite is the most effective. The sorbent capa-
cities for illite, activated carbon, acidic fly ash and activated alumina are
7.3, 7.2, 4.9, and 2.5 micrograms of nickel removed per gram of sorbent used
(see Table 8). These sorbents are also capable of handling the largest volume
of leachate before break-through of the nickel occurs. Break-through for the
illite-sand mixture occurs at 24 liters whereas, with acidic fly ash or activa-
ted carbon, break-through of the nickel did not occur even after 24 liters of
metal finishing leachate had passed through these sorbents (see Figure 15).
Fluoride Removal —
Significant removal of fluoride in the metal finishing sludge #3 leachate
appears to be difficult. Neither the illite-sand mixture, kaolinite-sand mix-
ture nor activated alumina (which were effective for removing fluoride from
the calcium fluoride leachate) seems suitable for treating the fluoride in
this leachate (see Figure 16). The removal capacities for the illite and
activated alumina are only 2.7, 3.6, and 11.4 micrograms of fluoride removed
per gram of sorbent used, respectively (see Table 8) as compared to 205, 183,
and 348 micrograms of fluoride removed per gram of sorbent used for the fluo-
ride sludge leachate (see Table 4).
Apparently, the basic conditions encountered in the effluents from the
lysimeters due to the addition of the alkaline metal finishing sludge leachate
minimizes the removal of the fluoride. In the illite lysimeter, fluoride is
removed where acidic conditions were encountered. Above 1 liter, where alka-
line pH was measured, break-through of the fluoride from the illite lysimeter
is observed (see Figure 16).
Organic Removal —
The activated carbon, acidic fly ash, and the illite-sand mixture appear-
ed to be the most effective sorbents for the removal of organics (see Figures
17 and 18).
The COD sorbent capacity exhibited by these sorbents are 1476, 1228, and
3060 micrograms of COD removed per gram of sorbent used, respectively (see
Table 8). The TOC removal capacities are approximately one-third of that ob-
tained with the COD measurements. A comparison of the sorbent capacities for
the illite-sand mixture and activated carbon reveal that the clay-sand mixture
is more effective than the activated carbon in removing the organics from this
leachate. These results are significant because an inexpensive sorbent has
been identified for treating the organics in the metal finishing sludge lea-
chate that shows as much promise as the activated carbon. The activated car-
bon is generally recognized as being an excellent sorbent for the removal of
organics in waste streams.
The sorbent capacity exhibited by these sorbents for the organics in the
metal finishing sludge #3 leachate is much higher than that obtained in the
removal of organics from the fluoride sludge leachate. Apparently, the acidic
conditions which favored the removal of organics from the calcium fluoride
sludge leachate are not required for the removal of organics from the metal
finishing sludge leachate. In all cases, with the exception of the initial
59
-------
0.20
D-n-a CHD/-D—n
Leachate
Activated Alumina
Activated Carbon
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
O Vermiculite
12 16
Effluent Volume, liters
Figure 15. Lysimeter Studies of Nickel Ion in Metal Finishing Sludge Leachate.
-------
CTl
n>
o
o
n
OJ
1.5
0.5
— Leachate
O Activated Alumina
D Illite
Kaolinite
6 8
Effluent Volume, liters
10
12
Figure 16. Lysimeter Studies of Fluoride Ion in Metal Finishing Sludge Leachate.
-------
01
I\3
Leachate
Activated Carbon
Ash (Acidic)
Ash (Basic)
D Illite
12 16
Effluent Volume, liters
Figure 17. Lysimeter Studies of COD in Metal Finishing Sludge Leachate.
-------
en
CO
Leachate
Activated Carbon
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
Vermiculite
12 16
Effluent Volume, liters
Figure 18. Lysimeter Studies of TOC in Metal Finishing Sludge Leachate.
-------
o
O)
o
(O
0)
CL
O)
•r-
U
„
0) O
O --1
° X
-—-A A- A A
A-"
X
A
A- A
Calcium Fluoride Sludge Leachate
Metal Finishing Sludge Leachate
Petroleum Sludge Leachate
10
20
30
Figure 19. Permeability Studies of Activated Carbon.
64
-------
fraction collected from the illite lysimeters, the pH of the effluent from the
lysimeters is basic (see Figure 11). In fact, the break-through of organics
did not occur for the illite when its effluent became basic as occurred with
illite in the removal of organics from the calcium fluoride sludge leachate.
Permeability Results--
In addition to the sorbent capacities exhibited by activated alumina,
activated carbon, acidic and basic fly ashes, illite-sand mixture, and vermi-
culite-sand mixture, for the various constituents in the metal finishing
sludge #3 leachate, variations in the permeability exhibited by these sorbents
as the leachate passes through were also examined. All the sorbents examined,
with the exception of activated carbon (see Figure 19) exhibited a decrease in
the coefficient of permeability. The results again show - as was the case
with the calcium fluoride sludge #3 leachate - that the activated alumina ex-
hibits the greatest reduction in the coefficient of permeability upon the
addition of influent (see Figure 20). This decrease was approximately a hun-
dred times greater than the decrease encountered with the fluoride leachate
(see Table 12). In addition, the coefficient of permeability for the basic
fly ash and the vermiculite-sand mixture showed significant decreases. This
decrease was approximately an order of magnitude greater than that observed
with the fluoride leachate.
Summary of Results
In view of the above results, the effective treatment of calcium, copper,
magnesium, nickel, and the organics can be best handled by the use of the
illite-sand mixture, vermiculite-sand mixture, and kaolinite-sand mixture in a
layered system. The vermiculite-sand mixture, although not so effective as
the illite, could be used to remove the calcium because the lysimeter results
for the illite suggest the possibility of leaching of calcium from this sor-
bent during the period when the effluent from the illite is acidic (see Figure
12). Kaolinite is effective for the fluoride removal. However, the reduction
in the permeability of vermiculite and permeability of kaolinite must be con-
sidered in the design of a bed to minimize the possibility of ponding at the
surface.
Activated alumina, which is effective for removing the majority of the
constituents in the metal finishing leachate, does not appear suitable for the
treatment of this leachate. The marked decrease in the coefficient of permea-
bility exhibited by this sorbent could result in the formation of an imperme-
able barrier.
Petroleum Sludge Leachate from an A.P.I. Gravity Separator
The effectiveness of activated alumina, activated carbon, bottom ash,
acidic and basic fly ashes, illite and vermiculite for the removal of calcium,
copper, magnesium, zinc, fluoride, cyanide, and tbe organics was investigated
under flowing conditions. These constituents were selected because they were
at concentration levels in the leachate that could be readily measured with
the atomic absorption spectrometer and specific ion probes. In addition, the
pH of the leachate, before and after it was treated with the sorbents, was also
monitored to study the effect that pH may have on the removal of the various
65
-------
o
(O
0)
O)
a.
o
•M
c
OJ
•r~*
O
O)
O
o
o
rH
X
O
1-1
X
vO
O
X!
10 20
Effluent Volume, liters
30
Figure 20. Permeability Studies of Sorbent Materials with Metal Finishing
Sludge Leachate.
66
-------
constituents by these sorbents. The results of these studies are shown in
Figures 21 to 29.
The monitoring of pH in the effluent leachate collected from the lysi-
meter containing the different sorbents again showed that the pH of the ini-
tial effluent samples was similar to that exhibited by each sorbent, but soon
approached that of the leachate (see Figure 21). In fact, the pH of each of
the sorbents became acidic after 6 liters of leachate was passed through.
An examination of the changes in pH of the ill He and acidic fly ash,
which both exhibit acidic conditions initially, revealed different behavior.
The effluent from the illite remained acidic, as would be expected since the
leachate added to it is acidic, but the acidic fly ash became alkaline and
then acidic again (see Figure 21). The reason for this latter observation is
not understood at this time.
Lysimeter effluent samples of activated alumina and bottom ash were not
collected and analyzed beyond a volume of 2 liters because of the marked re-
duction in permeability exhibited by both of these sorbents (see Figure 28).
Calcium Removal--
The removal of calcium in the petroleum sludge leachate by activated
alumina, activated carbon, illite-sand mixture, kaolinite-sand mixture, vermi-
culite-sand mixture, and bottom ash is shown in Figure 22. Here it may be
seen that both the illite-sand mixture and vermiculite-sand mixture are most
effective for removing calcium, followed by activated carbon and kaolinite-
sand mixture. Their sorbent capacities are 1110, 1010, 160 and 74 micrograms
of calcium removed per gram of sorbent used, respectively (see Table 11). The
initial effluent fraction collected from the illite lysimeter indicates that
calcium is being leached from this sorbent. However, as leachate is contin-
ually added to this lysimeter, the calcium begins to be removed.
The reason for the calcium being leached initially and then removed upon
further addition of leachate is not clear at this time. The alkaline condi-
tions which favored the removal of calcium in the calcium fluoride sludge
leachate and metal finishing sludge leachate by the illite do not appear es-
sential for the removal of calcium in the petroleum sludge leachate by the
illite. Acidic conditions were encountered in the effluent from the illite
until break-through of the calcium occurred at 9 liters (see Figure 22).
The activated alumina would probably exhibit a greater sorbent capacity
for calcium than the illite-sand mixture as seen from the lysimeter result
(see Figure 22) if additional effluent could be collected from this lysimeter.
However, such low flows were encountered through this sorbent after 2 liters
of leachate passed through, that the time required for collection of signifi-
cant volumes of effluent could not be justified within the scope of this in-
vestigation.
The vermiculite-sand mixture, although not as effective as the illite-
sand mixture in removing the calcium, should be used in combination with the
illite-sand mixture in a layered system. The illite exhibits leaching of
calcium in the initial fractions of effluent collected from the lysimeter.
67
-------
11
T
T
CO
m
-h
-tl
CD
3
c-f
TJ
o
A
O
®
o
D
Leachate
Activated Alumina
Activated Carbon
Bottom Ash
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
A
A Kaolinite
O Vermiculite
A 6 8
Effluent Volume, liters
10
Figure 21. Lysimeter Studies of pH in Petroleum Sludge Leachate.
-------
80
60
vo
m
-b
o
3
O
ft)
2
o
o
Q>
to
•^ 20
40
(158 mg/1, at 0.30 1)
I
— Leachate
O Activated Alumina
A Activated Carbon
D Ulite
O Vermiculite
A Kaolinite
I
I
I
o
8
10
246
Effluent Volume, liters
Figure 22. Lysimeter Studies of Calcium Ion in Petroleum Sludge Leachate.
12
-------
Thus, the vermiculite-sand mixture could remove this initial Teachable calcium
and reduce its concentration in the effluent.
Copper Removal--
Activated alumina, activated carbon, bottom ash, acidic and basic fly
ashes, illite and vermiculite were investigated for removal of the copper in
the petroleum sludge leachate. The most effective sorbents under flowing con-
ditions were observed to be acidic and basic fly ashes followed by vermicu-
lite-sand mixture, activated alumina, and bottom ash. The sorbent capacities
were 2.7, 2.5, 1.6, 0.39 and 0.04 micrograms of copper used per gram of sor-
bent used, respectively (see Table 11). Break-through of copper for the aci-
dic and basic fly ashes is not apparent even after these sorbents were treated
with 9 liters of leachate (see Figure 23). The acidic fly ash again appeared
to leach copper until the effluent leachate became alkaline. The copper be-
gan to be removed by this sorbent when slightly less than 2 liters of leachate
had been passed through this sorbent.
No removal of copper is observed with the illite. In fact, copper is
leached from this sorbent until 10 liters of effluent have been collected.
Alkaline conditions were not encountered in the effluent. The effluent re-
mained acidic for all the fractions collected (see Figure 21). Significant
variations are observed in the copper concentrations present in the initial
fractions of effluent collected from the lysimeters. These variations are
presumed to be the result of the different amounts of copper that are leached
from the sorbent into the effluent. Illite exhibited the greatest amount of
copper leaching in the static studies (see Table 10). In the lysimeter stu-
dies, it also exhibited the greatest amount of leaching. The initial 0.6
liters of illite effluent collected contains 1.4 mg/1 of copper.
The basic fly ash, although not as effective as the acidic fly ash in
the removal of copper, should be used in combination in a layered system with
acidic fly ash to remove the Teachable copper from the acidic fly ash. The
copper is leached from the acidic fly ash until its effluent becomes alkaline.
Magnesium Removal--
The basic fly ash and the kaolinite-sand mixture appear to be the most
effective, followed by illite-sand mixture, activated alumina, and vermicu-
lite-sand mixture for removing the magnesium ion according to the lysimeter
results (see Figure 24). Break-through of the magnesium occurs after 4 liters
of leachate is added to the basic fly ash and after 5 liters of leachate have
been added to the kaolinite. However, the kaolinite-sand mixture exhibited a
significantly greater sorbent capacity than the basic fly ash. There were
753 and 140 micrograms of magnesium removed per gram of sorbent used, respec-
tively. The larger sorbent capacity for the kaolinite resulted from the fact
that the amount of kaolinite used in the lysimeter was only 20 percent of
that used for the basic fly ash. The sorbent capacities for the illite-sand
mixture, activated alumina, and vermiculite-sand mixture were 180, 107, and
90 micrograms of magnesium removed per gram of sorbent used, respectively.
The acidic fly ash was observed to exhibit significant leaching of mag-
nesium in the initial 4 liters of effluent collected from the lysimeter.
The maximum concentration of magnesium that was encountered was 49.5 mg/1 in
70
-------
mg/
-------
the column effluent collected at 1.9 liters (see Figure 24). Changes in pH of
the effluent to more alkaline conditions do not appear to inhibit this leach-
ing. This leaching appeared in the effluents that exhibited acidic pH and
those that exhibited alkaline pH. The reason for this is not clear at this
time. The effect of changes in pH on specific ion exchange and adsorption
interactions between the contaminants in the leachate and these sorbents is an
area of study that may provide the answer to above results.
Zinc Removal--
The removal of zinc from the petroleum sludge leachate under flowing con-
ditions can be achieved with the use of acidic and basic fly ashes, followed
by the vermiculite-sand mixture, activated carbon, activated alumina and bot-
tom ash (see Figure 25). However, if account is taken that the vermiculite
used is only 20 percent of the fly ash used, then vermiculite appears to be
the most effective sorbent for zinc removal based upon the sorbent capacities.
The sorbent capacities exhibited by vermiculite, acidic and basic fly ashes,
and activated carbon, activated alumina and bottom ash are 6.4, 2.0, 2.0, 1.3,
0.43, and 0.23 micrograms of zinc removed per gram of sorbent used, respective-
ly (see Table 11).
The acidic fly ash exhibited leaching of the zinc when its lysimeter ef-
fluent is acidic but began to remove the zinc once this effluent became alka-
line. The alkaline condition occurred after slightly greater than 1 liter of
leachate has been added to this sorbent (see Figure 21).
Both the illite-sand mixture and kaolinite-sand mixture exhibited leach-
ing of the zinc until 9 and 6 liters of leachate were added to the 1111te and
kaolinite lysimeters, respectively. After the addition of these volumes, the
concentration of zinc in the effluents coincided with the concentration of
zinc in the influent and no removal of zinc was observed (see Figure 25).
The effluent from illite column exhibited only acidic conditions. The
lack of pH change in the lysimeter effluent may be responsible. Where there
was a pH change from acidic to basic effluent, such as for the acidic fly ash,
leaching of zinc from the acidic fly ash was inhibited.
Fluoride Removal--
The activated alumina, activated carbon, acidic and basic fly ashes, il-
lite, kaolinite, and vermiculite were examined for their effectiveness in re-
moving fluoride from the petroleum sludge leachate. The results indicated
that the illite-sand mixture, acidic and basic fly ashes are the most effec-
tive sorbents studied, followed by kaolinite-sand mixture, activated alumina,
and activated carbon, for removing fluoride. No removal of the fluoride by
the vermiculite-sand mixture was observed. The concentrations of fluoride in
the lysimeter effluent were the same as in the influent (see Figure 26).
The sorbent capacities exhibited by the illite-sand mixture, acidic fly
ash, basic fly ash, kaolinite-sand mixture, activated alumina and activated
carbon for fluoride removal are 12.1, 9.9, 7.2, 4.3, 3.4 and 1.3 micrograms of
fluoride removed per gram of sorbent used , respectively (see Table 11)
72
-------
CO
(49.5 mg/1, at 1.9 1)
A
— Leachate
O Activated Alumina
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
Vermiculite
Kaolinite
Figure 24.
Effluent Volume, liters
Lysimeter Studies of Magnesium Ion in Petroleum Sludge Leachate.
-------
0.14
0.12
2 0.10
CD
t~>
o
o
3
rfr
-S
c-l-
«j.
O
O
-h
'I '' '' I
Q(0.54 mg/1, at 0.6 1) ' ' ' '
(0 (0.24 mg/1, at 1.5 1)
10.40 rag/1, A D(0.22 mg/1, at 3.5 1)
at 0.25 1) *™?l SS(r A D (0.20 mg/1, at 5.5 1)
(0.24 mg/l, 0(0.16 mg/1, at 7.3 1)
3 L 1 * _L •*- /
._A D
0.08
0.06
0.04
0.02
O
Leachate
<^> Activated Alumina
A Activated Carbon
Bottom Ash
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
Kaolinite
Vermiculite
4 6
Effluent Volume, liters
10
Figure 25. Lysimeter Studies of Zinc Ion in Petroleum Sludge Leachate.
-------
1.6
en
G
ID
o
o
o
n>
o
o
Leachate
Activated Alumina
Activated Carbon
Fly Ash (Acidic)
Fly Ash (Basic)
Illlte
Kaolinite
Vermiculite
0.4
Effluent Volume, liters
Figure 26. Lysimeter Studies of Fluoride Ion in Petroleum Sludge Leachate.
-------
Cyanide Removal--
The activated alumina, activated carbon, acidic and basic fly ashes, bot-
tom ash, illite-sand mixture, kaolinite-sand mixture, and vermiculite-sand
mixture were investigated to determine their effectiveness in removing cyanide
from petroleum sludge leachate. The results indicated that all the sorbents,
with the exception of activated alumina and bottom ash, exhibited removals of
the cyanide (see Figure 27). Their sorbent capacities were 2.9, 3.3, 3.3,
15.5, 4.2, and 13.3 micrograms of cyanide removed per gram of sorbent used,
respectively (see Table 11). The illite-sand mixture followed by the vermi-
culite-sand mixture appeared to be the most effective based upon a comparison
of the sorbent capacities. No removal of cyanide was obtained using either
bottom ash or activated alumina.
Organic Removal--
The activated alumina, activated carbon, bottom ash, basic and acidic
fly ashes, illite-sand mixture, kaolinite-sand mixture, and vermiculite-sand
mixture were examined to determine their effectiveness in removing organics
from the petroleum sludge leachate, under flowing conditions. The results
indicate that all these sorbents exhibit some removal of the organics (see
Figures 28 and 29). A comparison of the sorbent capacities indicate that the
vermiculite-sand mixture is the most effective in removal of COD and TOC,
followed by the illite-sand mixture, basic and acidic fly ashes, activated
carbon, activated alumina, and bottom ash in decreasing order (see Table 11).
It should be noted from the sorbent capacities that the vermiculite-sand
mixture is significantly more effective than the activated carbon in removing
the organics from this leachate for the 10 liters of leachate added to these
lysimeters. This finding is significant in that activated carbon is consider-
ed to be an effective sorbent for the removal of organics from waste streams.
Permeability Results—
The type of leachate being treated by a sorbent has a significant effect
on the permeability of the sorbent, with the exception-of activated carbon.
The initial magnitude of the coefficient of permeability exhibited by the
activated carbon was not influenced by the leachate (see Figure 19). Also,
it did not change significantly upon the addition of leachate. On the other
hand, the activated alumina decreased markedly upon the addition of the lea-
chate (see Figure 30). The coefficient of permeability for bottom ash also
exhibited a parallel behavior.
The coefficient of permeability for acidic and basic fly ashes, illite-
sand mixture and vermiculite-sand mixture in general exhibited far less var-
iation upon the addition of the petroleum sludge leachate than either the
activated alumina or bottom ash. The coefficient of permeability for the
kaolinite initially was much lower than the above sorbents. However, it ex-
hibited less of a decrease upon the addition of leachate than either the bot-
tom ash or activated alumina.
Summary of Results
The basic fly ash, the vermiculite-sand mixture and the kaolinite-sand
mixture appear to be the most effective sorbent combination for treating the
76
-------
0.25
-t>
-Jj
to
o
o
o
n>
-s
Q>
O
O
-h
o
0.20
0.15
0.10
0.05
O
A
O
®
9
D
O
Leachate
Activated Alumina
Activated Carbon
Bottom Ash
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
Vermiculite
Kaolinite
0 2 4 6 8 10
Effluent Volume, liters
Figure 27. Lysimeter Studies of Cyanide Ion in Petroleum Sludge Leachate.
12
-------
300
o
ft)
01
O
-h
O
O
200
00
100
Leachate
O Activated Alumina
Activated Carbon
Bottom Ash
Fly Ash (Acidic)
Fly Ash (Basic)
Illite
Vermiculite
A
O
D
O
t
468
Effluent Volume, liters
10
12
Figure 28. Lysimeter Studies of COD in Petroleum Sludge Leachate.
-------
160
120
o
o
vo
Leachate
Activated Alumina
Activated Carbon
O Bottom Ash
41 Fly Ash (Acidic)
• Fly Ash (Basic)
G Illite
o Vermiculite
6 8
Effluent Volume, liters
Figure 29. Lysimeter Studies of TOC in Petroleum Sludge Leachate.
12
-------
10
u
OJ
to
o
•p
-------
petroleum sludge leachate. The basic fly ash would be used for removing the
copper and fluoride, the vermiculite-sand mixture for the calcium, zinc, cya-
nide and the organics and the kaolinite-sand mixture for removing the magnesium
ion.
The kaolinite-sand mixture is significantly more effective than the other
sorbents for removing the magnesium ion based upon a comparison of the sorbent
capacities. Hence, it is included in the above combination even though it
exhibited leaching of zinc ion. The presence of a significant amount of ver-
miculite-sand mixture in a layered system could minimize this problem.
Although illite was found to be the most effective for the removal of
calcium, fluoride and cyanide based upon a comparison of the sorbent capaci-
ties, the illite does not show promise because it exhibited leaching of copper
and zinc in over half of the effluent fractions collected from the lysimeter.
Similarily, the acidic fly ash was found to be the most effective for the re-
moval of the copper and the next most effective for fluoride, but it was not
selected because in over two-thirds of the effluent fractions that were analy-
zed for magnesium, the acidic fly ash showed leaching of this ion.
81
-------
REFERENCES
1. Deb, P.K., A.J. Rubin, A.W. Launder, and K.H. Mancy, (1966), "Removal of
C.O.D. from Wastewater by Fly Ash" Engineering Bull., Purdue University,
No. 121.
2. Nelson, M.D. and Carmen F. Fuarino, (Nov. 1969), "The Use of Fly Ash in
Municipal Waste Treatment," Journal WPCF, Vol. 41, No. 11, pt. 1, pgs.
1905-1911.
3. Ballance, R.C., J.P. Capp and J.C. Burchinal, (1966), "Fly Ash as a
Coagulant Aid in Water Treatment" U.S. Dept. Interim, Bureau of Mines,
Report of Investigations - 6869.
4. Grim, Ralph E., (1967), Clay Mineralogy (2nd Ed.), McGraw Hill Book Co.,
Inc., New York.
5. Brown, G. (ed.), (1961), The X-Ray Identification and Crystal Structures
of Clay Minerals, Jarrold and Sons, Ltd., Norwich.
6. Fried, M. and R.E. Shapiro, (1956), "Phosphate Supply Pattern of Various
Soils," Soil Sci. Soc. Am. Proc., Vol. 20, p. 471-475.
7. Olson, Sterling R. and Frank S. Watanable, (1957), "A Method to Determine
a Phosphorous Absorption Maximum of Soils as a Measure by the Langmuir
Isotherm," Soil Sci. Soc. Am. Proc., Vol. 21, p. 144-149.
8. Ellis, B.G. and A.E. Erickson, (1969), "Movement and Transformation of
Various Phosphorous Compounds in Soils," Report to Michigan Water Resources
Commission.
9. Tiller, K.G., (1967), "Silicic Acid and the Reactions of Zinc with Clays,"
Nature, Vol. 214, p. 852.
10. Sharpless, R.G., E.F. Wallihan, and E.F. Peterson, (1969), "Retention of
Zinc by Some Arid Zone Soil Materials Treated with Zinc Sulfate," Soil Sci.
Soc. Am. Proc., Vol. 33, p. 901-904.
11. Bittel, J.E. and Raymond J. Miller (1974), "Lead, Cadmium, and Calcium
Selectivity, Coefficients on a Montrnorillonite. Illite, and Kaolinite,"
J. Environ. Quality, Vol. 3, No. 3, p. 250-253.
12. Fuller, Wallace H., Collen McCarthy, B.A. Alesii, and Elvia Niebla,"
(1976), "Liners for Disposal Sites to Retard Migration of Pollutants,"
Residual Management by Land Disposal, Proc. Hazardous Waste Research
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Symposium, U.S.E.P.A., p. 112-126.
13. Griffin, R.A., R.R. Frost and N.F. Shimp, (1976)," Effect of pH on Removal
of Heavy Metals from Leachates by Clay Minerals," Residence Management by
Land Disposal, Proc. Hazardous Waste Research Symposium, U.S.E.P.A.,
p. 259-268.
14. McHenry, J.R., D.W. Rhodes and P.P. Rowe, (Dec.-1955), "Chemical and
Physical Reactions of Radioactive Liquid Wastes with Soils," in Sanitary
Engineering Aspects of the Atomic Energy Industry, A.E.G. Publication No.
TID-7517, Cincinnati, Ohio.
15. Likens, Gene E., (Nov. 22, 1976), "Acid Precipitation", Chemical and
Engineering News, pp. 29-44.
16. E.P.A. (1974), Methods of Chemical Analysis of Water and Waste," U.S.E.P.-
A. Tech. Transfer, Cincinnati, Ohio.
17. Scott, R., (1963), Principles of Soil Mechanics. Addison-Wesley Publish-
ing Co., Waltham, Mass.
18. U.S. Public Health Service, 1962 Public Health Service Drinking Water
Standards PHS Pub. No. 956, Washington, D.C.
83
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-78-024
3. RECIPIENT'S ACCESSION'NO.
4. TITLE ANDSUBTITLE
SORBENTS FOR FLUORIDE, METAL FINISHING, AND PETROLEUM
SLUDGE LEACHATE CONTAMINANT CONTROL
5. REPORT DATE
March 1978 (Issuing
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Paul C. Chan, Robert Dresnack, John W. Liskowitz
Angelo Perna, Richard Trattner
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
New Jersey Institute of Technology
Newark, New Jersey 07102
10. PROGRAM ELEMENT NO.
1BB610
11. CONTRACT/GRANT NO.
B803717
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory—Gin.,OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final report 6/75 to 5/77
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
Project Officer: Fred Ellerbusch
Contact: Robert E. Landreth (513) 684-7871
16. ABSTRACT
This report covers the initial laboratory studies carried out to identify the most
Dromising sorbents that may be used to significantly reduce the concentration of meas-
urable contaminant in calcium fluoride sludge leachate, metal finishing sludge leachate
and petroleum sludge leachate. Laboratory evaluations were made of bottom ash, acidic
and basic fly ashes, vermiculite, illite, activated carbon, kaolinite, natural zeolite,
activated alumina, and cullite for the removal of contaminants in the leachate and
liquid portion of these three industrial sludges.
Batch and lysimeter studies were carried out to evaluate the static and dynamic
orbent capacity for the constituents present in the leachate. Permeability exhibited
by these sorbents when contacted with an industrial sludge leachate was also studied.
he pH, conductivity, chemical oxygen demand (COD), total organic carbon (TOC), cationii
and anionic species in the leachate before and after contact with the sorbent materials
and the coefficient of permeability were determined.
Considerable variations in composition and concentration of leachate constituents
vere shown. Batch and lysimeter studies revealed that no single sorbent could be used
to reduce the concentration of the constituents found in the leachate of a specific
ludge; rather, combinations of two or more sorbents could be used.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS C. COS AT I Field/Group
Leaching
Pollution
Waste treatment
Linings
Sorbents
Solid waste management
Industrial sludaes
13B
3. DISTRIBUTION STATEMEN1
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
94
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
84
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