EPA-600/2-75-043
October 1975
Environmental Protection Technology Series
SANITARY LANDFILL STABILIZATION WITH
LEACHATE RECYCLE AND RESIDUAL TREATMENT
Municipal Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
-------
RESEAECH REPORTING SERIES
Research reports of the Office of Research and Development, U.S.
Environmental Protection Agency, have been grouped into five series.
These five "broad categories vere established to facilitate further
development and application of environmental technology. Elimination
of traditional grouping was consciously planned to foster technology
transfer and a maximum interface in related fields. The five series
are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
k. Environmental Monitoring
5- Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to
develop and demonstrate instrumentation, equipment and methodology to
repair or prevent environmental degradation from point and non-point
sources of pollution. This work provides the new or improved tech-
nology required for the control and treatment of pollution sources to
meet environmental quality standards.
This document is available to the public through the National Technical
Information Service, Springfield, Virginia 22l6l.
-------
EPA-600/2-75-OU3
October 1975
SANITARY LANDFILL STABILIZATION WITH
LEACHATE RECYCLE AND RESIDUAL TREATMENT
by
Frederick G. Pohland
School of Civil Engineering
Georgia Institute of Technology
Atlanta, Georgia 30332
Grant No. R-801397
Project Officer
Dirk Brunner
Solid and Hazardous Waste Research Division
Municipal Environmental Research Laboratory
Cincinnati, Ohio 1*5268
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF AIR, LAND, AND WATER USE
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 1*5268
-------
DISCLAIMER
This report has been reviewed "by the Municipal Environmental
Research Laboratory, U.S. Environmental Protection Agency, and
approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the U.S.
Environmental Protection Agency, nor does mention of trade names
or coumercial products constitute endorsement or recommendation for
use.
11
-------
FOREWORD
Man and his environment must toe protected from the adverse effects
of pesticides, radiation, noise, and other forms of pollution, and the
unwise management of solid waste. Efforts to protect the environment
require & focus that recognizes the interplay between the components of
our physical environment—air, water, and land. The Municipal Environ-
mental Research Laboratory contributes to this multidisciplinary focus
through programs engaged in
9 studies on the effects of environmental contaminants on
the biosphere, and
0 a search for ways to prevent contamination and to recycle
valuable resources.
This research has provided the laboratory evaluation of experimental
landfills that forms the basis for design and operation of the sanitary
landfill method as a controlled process that allows assurance of environ-
mental protection over a short management period. Recirculation of
leachate in a controlled manner allows the rapidly stabilized solid waste
deposit to be considered for earlier and more extensive potentials for
land reclamation and ultimate use. This innovative contribution to solid
waste control technology must be developed further on a larger scale before
widespread application.
111
-------
ABSTRACT
JThis report presents the results of studies with an experimental system which
was developed to simulate landfill disposal of domestic-type refuse but with
opportunities for comparison of the characteristics of normal leachate pro-
duction with leachate collected, adjusted and recirculated back through the |
refuse in a manner analogous to the operation of an anaerobic trickling filter.)
The basic experimental system consisted of four 3-foot diameter columns con-*-"^
taining 10 feet of compacted refuse covered with 2.5 feet of soil. The system
was equipped to permit collection and analysis of changes in characteristics
of the refuse, gas produced and leachate generated in response to intercepted
rainfall. Of particular interest were the effects of initial sludge seeding
and pH control on the rate of biological stabilization of the refuse and
leachate constituents.
Since decisions on the acceptability of the leachate for ultimate disposal
into some receptor, and hence the time when leachate recycle would no longer
be needed, were considered functions of environmental and/or regulatory
requirements, the basic leachate recycle investigations were complemented by
separate physical-chemical as well as biological leachate treatment studies.
Results of analyses, procured over an experimental period of about three years,
indicated that leachate recycle was very beneficial in accelerating the removal
of at least the readily available organics from the refuse and leachate. Com-
pared to the leachate emanating from a control unit which contained significant
concentrations of pollutants even at the end of the experimental period, the
leachate subjected to recirculation through the refuse exhibited rapid decreases
in organic concentrations in a matter of months. This rate of decrease in
organic leachate pollutants was further enhanced by the initial addition of
sewage sludge and/or by pH control.
Results from the separate leachate treatment studies indicated that leachate
could be successfully treated by either aerobic or anaerobic biological pro-
cesses and that the effluent residuals could be polished by activated carbon
adsorption and/or ion exchange either separately or in combination. The
degree of residual treatment is predictable and therefore responsive to what-
ever effluent requirement may be imposed.
This report was submitted in fulfillment of Georgia Institute of Technology
Project Number E-20-6^2 under the sponsorship of the U. S. Environmental
Protection Agency, Research Grant R-801397.
IV
-------
CONTENTS
Page
Disclaimer ±±
Foreword iii
Abstract iv
List of Figures vi
List of Tables viii
Acknowledgements x
Sections
I Conclusions 1
II Recommendations 2
III Review of Literature 3
IV Materials and Methods 12
V Presentation of the Data 21
VI Discussion 67
VII Separate Treatment of Leachate and Leachate
Residuals 8l
VIII References 102
v
-------
FIGURES
No. Page
1 Simulated Landfill Columns 13
2 Leachate Distribution System 15
3 Results of Cover Soil Leaching Study 2^
k Internal Temperature Fluctuations of the
Simulated Lanifills 26
5 Biochemical Oxygen Demand of Leachate ^7
6 Chemical Oxygen Demand of Leachate ^°
7 Total Organic Carbon Concentration of Leachate ^9
8 Valeric Acid Concentration of Leachate 50
9 Butyric Acid Concentration of Leachate 51
10 Propionic Acid Concentration of Leachate 52
11 Acetic Acid Concentration of Leachate 53
12 pH and Total Volatile Acid Concentration of
Leachate 5^
13 Acidity of Leachate 55
ill Alkalinity of Leachate 56
15 Concentrations of Organic and Ammonia Nitrogen
in Leachate 57
l6 Phosphate and Chloride Concentrations of Leachate 5°
17 Iron and Sodium Concentrations of Leachate 59
18 Manganese, Magnesium and Calcium Concentrations
of Leachate
VI
-------
FIGURES (continued)
No.
19 Total Hardness of Leachate 6l
20 Solids Concentration of Leachate 62
21 Addition of Neutralizing Agent, Sodium Hydroxide,
During Phase II 63
22 Completely Mixed Continuous Plow Reactor System 83
23 Anaerobic Biological Treatment of Leachate in
Continuous Culture 86
2k Aerobic Biological Treatment of Leachate in
Continuous Culture 88
25 Removal of Metals from Aerobic Biological
Leachate Treatment Effluent by Cation Exchange 91
26 Effect of Cation Exchange on pH and Acidity of
Effluents from Aerobic Biological Treatment of
Leachate 93
27 Effect of Cation Exchange on Total Dissolved
Solids and Specific Conductance of Effluent
from Aerobic Biological Treatment of Leachate 9^
28 Mixed Resin Ion Exchange Treatment of Effluent
from Aerobic Biological Treatment of Leachate 95
29 Effect of Mixed Resin Ion Exchange on Dissolved
Solids and Specific Conductance of Effluent from
Aerobic Biological Treatment of Leachate 97
30 The Freundlich Isotherm of Carbon Adsorption on
Effluent of Aerobic Biological Treatment of Leachate 98
31 Possible Scheme for On-Site Treatment of Non-Recycled
Leachate
VI1
-------
TABLES
No. Page
1 Variations in Leachate Composition 7
2 Stimulating and Inhibitory Concentrations of
Alkali and Alkaline-Earth Cations to the
Digestion of Sewage Sludge 9
3 Composition of Simulated Refuse 1^-
k Initial Composition of the Organic Fraction
of the Simulated Refuse Used During Phase I
and Phase II 21
5 Changes in Composition of the Organic Fraction
of the Simulated Refuse for Each Test Unit
During Phase I and Phase II 22
6 Results of Cover Soil Leaching Experiments 25
7 Cumulative Surface Settlement of the Simulated
Landfills 28
8 Moisture and Precipitation Intercepted by
Simulated Landfills During Phase I 30
9 Moisture and Precipitation Intercepted by
Simulated landfills During Phase II 35
10 Concentrations of Extracted Materials in
Leachate Obtained from Control Landfill (Fill 1) 39
11 Concentrations of Extracted Materials in Leachate
Obtained from Recirculated Landfill (Fill 2) In
12 Concentration of Extracted Materials in Leachate
Obtained from Fill 3 ^3
13 Concentration of Extracted Materials in Leachate
Obtained from Fill k ^5
Ik Composition of Gas Produced During Phase II °5
Vlll
-------
TABLES (continued)
Ho. Page
15 Analysis of Raw Primary Sludge Added to Fill 4
in Phase II 6°
16 Estimated Incremental and Total Mass of Materials
Extracted from Fill 1 During Phase I 79
17 Characteristics of Leachate Used During Separate
Biological Treatment °2
18 Results of Separate Anaerobic Biological Leachate
Treatment in Continuous Culture Without Solids
Recycle °5
19 Results of Separate Aerobic Biological Leachate
Treatment in Continuous Culture Without Solids
Recycle b7
20 Cation Exchange Treatment of Leachate Residuals 90
21 Mixed Resin Treatment of Leachate Residuals 92
22 Carbon Treatment of Leachate Residuals 9^
23 Combined Mixed Resin Ion Exchange and Carbon
Treatment of Leachate Residuals 99
IX
-------
ACKNOWLEDGEMENTS
The participation and efforts of Messrs. W. F. Armentrout, L. I. Bortner,
P. R. Maye, P. R. Karr, S. J. Kang, C. G. Breland, M. Mao, F. C. Mingledorff,
R. R. Bouton, C. L. Simmons and V. J. Pujals in the conduct of the research
detailed in this report, and the able assistance of Messrs. E. E. Ozburn,
R. A. Wiscovitch, and J. W. Hudson of the SanitaryTEngineering Program at the
Georgia Institute of Technology are gratefully acknowledged.
Appreciation is also extended to the administrative and financial support
provided in part by the School of Civil Engineering at the Georgia Institute
of Technology and bv the Environmental Protection Agency through its Solid
Waste Training Program.
Finally, to Mr. Dirk Brunner, EPA Project Officer, a special recognition and
thanks for agency support and personal interest in the successful completion
of the project.
-------
SECTION I
CONCLUSIONS
The results of experimental studies on the treatment of leachate by recycle
and/or separate biological and physical-chemical methods have indicated that
a combination of these methods may be necessary to reduce the pollutional
potential of leachate from refuse disposal sites to a concentration acceptable
for ultimate disposal.
Recirculation of leachate through a landfill promotes a more rapid develop-
ment of an active anaerobic bacterial population of methane formers, increases
the rate and predictability of biological stabilization of the readily avail-
able organic pollutants in the refuse and leachate, dramatically decreases the
time required for stabilization, and reduces the potential for environmental
impairment.
Leachate recirculation with pH control and initial sludge seeding may further
enhance treatment efficiency so that the time required for biological stabili-
zation of the readily available organic pollutants in the leachate can be
reduced to a matter of months rather than years with the opportunity for con-
trolled final discharge and/or treatment of residuals as may be required.
Separate aerobic and anaerobic biological processes have proven satisfactory
for treatment of leachate; residual organics and inorganics in the effluent
are best removed by carbon adsorption followed by mixed resin ion exchange.
The degree of residual treatment is predictable and therefore responsive to
whatever effluent requirement may be imposed.
Based upon the concept of leachate containment, collection and treatment
either by recycle through a landfill and/or by separate biological and
physical-chemical methods, the landfill of the future may well be conceived
as a controlled process conducive to accelerated stabilization, environmental
protection, and rapid realization of potentials for land reclamation and/or
ultimate use.
-------
SECTION II
RECOMMENDATIONS
The studies reported herein have formed the basis for introduction of a
relatively new and innovative method for management and control of solid
waste disposal sites. However, the studies were somewhat limited in scope
and application since they were conducted on a laboratory scale essentially
as a research investigation.
Sufficient data have been accumulated to justify an extension of the studies
to pilot- or full-scale landfill operations. In addition to the development
of some test cells, simultaneous investigations of alternatives for leachate
containment, recycle, and residual treatment should be conducted together
with studies on: the predictability of refuse and leachate stabilization with
respect to rate and time required for eventual use of the site; the potentials
for possible energy recovery either from gas (methane) produced during rapid
biological stabilization or from the stabilized refuse as a raw material for
resource recovery; the variance between leachate problems, control procedures
and requisite treatment accountable to refuse characteristics, environmental
stresses, and operational procedures; and the economic and design factors
necessary to support the development and acceptability of a viable system.
Such information would also support the decision process necessary to deter-
mine applicability and potential environmental hazard and would therefore
contribute to the state of the art and possible development of guidelines for
landfill disposal of solid waste.
-------
REVIEW OF THE LITERATURE
Whenever refuse is deposited on land, some of its organic and inorganic
constituents are subject to leaching as water percolating through the refuse
carries these materials into aquifers, surface streams or impoundments. Such
leaching of pollutants may seriously impair water quality and endanger the
health and welfare of the community.
The leachate formed by such action has been defined as the contaminated
liquid which is discharged from a landfill to either surface or subsurface
receptors . For pollution of ground water to occur, three conditions are
required: (l) the refuse must be located over, adjacent to, or in an aquifer;
(2) super saturation must exist in the fill due mainly to the movement of
ground water into the fill and the percolation of precipitation and surface
water runoff; and (3) leached fluids must be produced and this leachate must
be capable of entering an aquifer .
EFFECT OF LANDFILLS ON WATER QUALITY
Based on the study of an existing landfill in an abandoned gravel pit,
Anderson and Dornbush reported that ground water in the immediate vicinity
of the landfill and in direct contact with the fill exhibited an increase in
ionic strength and that the impairment of water quality by excess ions de-
creased with distance from the fill area. Analyses on samples obtained at
various depths from 22 wells located around the landfill indicated that the
chloride and sodium concentrations and specific conductance were the most
appropriate chemical parameters of those employed to measure leachate pol-
lution. It was also reported that the pond downstream from the fill area
served to reduce the hardness and alkalinity during the summer months.
U fl
Hughes, et al. investigated the characteristics of four active land-
fills of varying ages in northeastern Illinois. Piezometers were installed
at various points in the landfills and core samples were obtained at the pie-
zometer locations. The results indicated that ground water mounds had formed
under each fill and that leachate moved away from the fill area through
springs in the superficial sand layer around the fills and vertically down-
ward into the subgrade. Analyses of samples revealed that ground water quality
improved with age of the fill material and with distance from the fill area.
Ground water quality also varied greatly over short vertical and horizontal
distances within the fill.
-------
Q
Coe reported from studies at the University of Southern California
that the ground water under the Riverside Landfill contained BOD, chloride,
sodium, and sulfate increases of 26, 10, 9 and 8 times, respectively, over
the concentrations found in the natural and uncontaminated ground water. In
general, the ground water at all points sampled downstream of the fill showed
significant increases in mineral constituents, hardness, and alkalinity; how-
ever, the effects were considerably less than those found in ground water
under the fill.
Calvert reported an increase in hardness, calcium, magnesium, total
solids and carbon dioxide in a well 500 feet from., a refuse storage pit at
a garbage reduction plant. Carpenter and Setter sampled water at the
bottom of a refuse fill and obtained average BOD, alkalinity and chloride
concentrations of l,98?j 3»867, and 3j506 mg/1, respectively. Lang re-
ported the pollution of well water 2,000 feet from a fill.
13
Davison studied the characteristics of refuse tips in England and
concluded that such effluents could promote the growth of bacterial slimes
or fungus in groundwater supplies and lead to taste and odor problems.
The pollution of the surface water supply of Kansas City, Mo., reported
by Hopkins and Paplisky was atrributed to the reactivation of an industrial
waste landfill with the subsequent leaching of organic compounds directly into
the Missouri River one mile above the city's water intake.
QUANTITIES OF LEACHATE PRODUCED BY LANDFILLS
Remson, e_t al. have developed a moisture routing model based on the
equation of continuity to predict the quantity of leachate which would be
produced by a landfill for a given refuse, soil, and precipitation pattern.
Sample calculations for a hypothetical landfill composed of eight feet of
compacted refuse and two feet of soil cover were provided together with
characteristics of a municipal refuse. Calculations were simplified by
assuming: (l) a fully vegetated fill surface with plants whose roots draw
water from all parts of the soil cover but not the underlying fill; (2) no
moisture removed by diffusing gases; (3) infiltration of all rainfall;
(h) a soil cover and refuse with uniform hydraulic characteristics in all
directions; and (5) a freely draining landfill and substrata. The examples
assumed instantaneous placement of a refuse of various moisture contents and
at various times of the year. The average rainfall was superimposed and the
amounts of leachate produced calculated.
A graphical phase relationship presented by Fungaroli showed a definite
lag between initial addition of water and the production of leachate as well
as a correlation between water added and leachate produced. The relation-
ships between field capacity and dry density of the refuse and the effect of
cover soil type on infiltration into the fill indicated that denser refuse
yielded higher field capacity and therefore a longer time to saturate the
landfill and produce leachate. A light clay loam proved to be the best cover
material because of the longer time required to bring a given thickness to
field capacity and allow percolation into the fill. It was concluded that
-------
leachate production could be attributed to refuse composition and placement,
channeling and/or type of wetting front.
Experiments by Merz and Stone with landfill cells of approximately
20 feet in depth and covered with two feet of earth indicated that little
leachate percolated into the subgrade beneath the landfills. Water was
applied in sufficient quantities to the refuse cells by a sprinkler system
so as to augment the natural rainfall and match the yearly rainfall of Seattle,
Wash, for one cell and to provide enough water to allow the growth of a thick
turf on the other. The moisture content of the soil cover, refuse and sub-
grade was obtained from core samples taken at various points in the cells.
Differences in moisture content at different levels (bands) in the cells were
noted. Except for the soil cover, the top band of the cell,simulating rain-
fall patterns of Seattle, was always drier than the other bands. During the
final year of the project, the middle band maintained a higher moisture con-
tent than the bottom band thereby indicating that the fill material had a high
holding capacity. The adobe-shale subgrade beneath the cell maintained a
moisture content only seven percent greater than native soils taken from the
same depth. The earth cover of the other cell had a lower moisture content
than the three bands at all times except for two core samples. rj.'here was no
relationship between the moisture content of the top and middle bands and the
subgrade averaged about the same water content as observed before for the
other cell until it was accidently flooded. After flooding, the moisture
content of the subgrade increased 38 percent.
CHARACTERISTICS OF IEACHA.TE PRODUCED BY LANDFILLS
Theoretically, any time the amount of water entering a landfill exceeds
the field capacity of the deposited refuse, leachate will be produced and
discharged. Leachate characteristics may vary widely and no general method
has been developed to forecast the exact composition of leachate which may be
associated with a particular fill at a particular time. Leachate character-
istics are influenced not only by the materials placed in the fill but also
by the stage of decomposition and the physical characteristics of the perco-
lating water and the soil adjacent to the fill or used for cover. Therefore,
leachate will be composed of various concentrations of pollutants in the form
of dissolved and finely suspended organic and inorganic materials as well as
products of microbial activity.
Several studies have been performed to ascertain the characteristics of
leachate. Coe" reported that the color of leachate ranged from green to brown,
and that odors were similar to those of garbage (decomposing food stuffs) and
oil and grease (hydrocarbons). Qasim ' noted that fresh leachate samples were
dark green and became darker and septic soon after collection.
Qasim and Burchinal17' reported experimental results obtained from
examination of leachate produced from simulated landfills consisting of 36-
inch concrete cylinders containing municipal refuse and covered to exclude
precipitation. Water was applied by an internal sprinkling system and leachate
samples were collected and analyzed for alkalinity, acidity, pH, BOD, total
hardness, calcium, magnesium, sodium, potassium, iron, sulfate, phosphate,
-------
chlorides, nitrogen, solids, tanin and lignin, coliforms and total plate
counts. Leachate analyses indicated an initial increase of pollutants
which decreased after four weeks depending upon the depth of fill and extent
of stabilization. The deeper fills took longer to become saturated so that
leaching started later. Moreover, leachate liquors from the deeper fills
were stronger although concentrations of pollutants per foot of fill decreased
as the depth of fill increased.
19
Fungaroli and Steiner have reported the results from examination of
leachate from an insulated lysimeter. The leachate was generally acidic
with the usual pH range between 5-0 and 6.5 except for some high and low
peaks. Erratic fluctuations in pH occurred during low leachate production
whereas relatively constant pH corresponded to periods of large production.
This implied that the volumetric flow rate of leachate through the refuse
was a moderating factor for pH. In addition, during low flow periods when
the pH was greater than 5-5? the iron concentration in the leachate was low,
about 100 mg/1. Conversely, when leachate production was high and the pH
less than 5-5> the iron concentration was high. The maximum combined concen-
tration for ferric and ferrous iron exceeded 1600 mg/1. The quantity of
leachate produced also influenced the total solids concentration. The total
solids increased with increasing leachate volume and decreased with decreasing
volume. This indicated the "washing-action" as the leachate moved through the
refuse. Similarly, after the initially high concentration of 50,000 mg/1
COD, the COD remained between 20,000 to 22,000 mg/1 during the duration of
the two-year study. The leachate was also analyzed for chlorides, copper,
zinc, nitrogen, phosphorous, sodium, sulfate, and hardness; no trends or
interrelationships between various ions were apparent.
20
Merz reported results from examination of leachate from two "perco-
lation bins" containing 10 feet of compacted domestic refuse. The con-
centrations of the organic and inorganic components were high in the first
samples of leachate and increased for five weeks. The initial BOD was 33jlOO
mg/1 and remained high for eight months. An 80 percent decrease in BOD
occurred after eight months; after 13 months the BOD had been reduced to
375 mg/1. The maximum ion concentration in the leachate was 10 to 20 times
the concentration found in the water applied to the refuse. The ammonia,
organic nitrogen and phosphate concentrations of the leachate were as much
as 10,000 times the concentration found in natural waters. It was concluded
that continuous leaching of an acre-foot of fill would result in minimum
extration of about 1.5 tons of sodium and potassium, 1.0 ton of calcium and
magnesium, 0.91 ton of chlorides, 0.23 ton of sulfates, and 3-9 tons of
bicarbonate. Removals of these quantities would take place in less than
one year after which removals would continue slowly with some ions always
remaining.
Table 1 contains the results of several leachate studies. These results
are influenced by differences in characteristics of the refuse and percolatin
water and by limitations in sampling and analytical techniques.
-------
Table 1. VARIATIONS IN LEACHATE COMPOSITION
Analysis
12
13
lit
15
16
17
pH
Total hardness, mg/1 as CaCO-
Total alkalinity, mg/1 as CaCO
Total iron, mg/1
Sodium, mg/1
Potassium, mg/1
Sulfate , mg/1
Chloride , mg/1
Nitrate, mg/1 H
Ammonia , mg/1 N
Total organic nitrogen, mg/1 N
COD, mg/1
BOD5, mg/1
Total dissolved solids , rng/1
Specific conductance, ^mhos/cm
5.6
8,120
8,100
305
1,805
1,860
630
2,21*0
-
81*5
550
-
32,1*00
-
-
5.9
3,260
1,710
336
350
655
1,220
-
5
11*1
152
7,130
7,050
9,190
-
8.3
537
1,290
219
600
-
99
300
18
-
-
-
-
2,000
-
-
-
-
1,000
-
-
-
2,000
-
-
-
750,000
720,000
-
-
-
8,700
-
-
-
-
91*0
1,000
-
-
-
-
-
11,251*
-
-
500
-
-
-
-
21*
220
-
-
-
-
-
2,075
-
-
900
-
1*0
-
-
225
-
-
160
-
3,850
1,800
-
3,000
-
290
-
2
-
-
100
-
-
100
-
. 21*6
18
-
2,500
7.63 5.60
8,120 650
9,520 730
305 6
1,805 85
l,86o 28
730 2l*8
2,350 90
-
81*5 0.2
550 2
-
33,100 81
-
-
7A
-
-
-
-
-
21*8
1,81*5
-
668
101
-
5,1*91
-
-
6.1*
-
-
206
1,200
-
91*0
1,100
-
-
-
5,700
-
1,251*
-
M
2,500
-
152
1,100
920
970
1,600
196
-
-
21,120
-
15,830
-
5.6
30
-
28
300
110
65
1*85
10
-
-
282
-
l,7<*o
-
8.1* 5.7
-
9,1*50 100
-
-
-
-
12,300 280
-
-
-
-
7,330 5.9
-
-
6.3
7,6oo
10,630
175
581*
1,050
615
951
-
!*73
288
-
lit, 760
-
-
6.lt8
13,100
16,200
51*6
1,1*28
2,535
1,002
2,000
-
756
661*
-
26,91*0
-
-
5.88
10,950
20,850
860
1,!*39
3,770
768
2,310
-
1,106
1,U16
-
33,360
-
-
Sample Identification:
1., 2., 3. From Eef. 20; no age of fill specified.
1*. From Ref. 21; Initial leachate.
5. From Ref. 21; 3-year old fill.
6. From Ref. 21; 15-year old fill.
7. From Ref. 22; new fill.
8. From Ref. 22; old fill.
9. From Ref. 23; maximum and minimum.
10. From Ref. 21*
11. From Ref. 7
12. From Ref. 1; Site 1*.
13. From Ref. 1; Site B
ll*. From Ref. 11; maximum and minimum.
15. From Ref. 17; Cylinder A, maximum.
16. From Ref. 17; Cylinder B, maximum.
17. From Ref. 17; Cylinder C, maximum.
-------
PARAMETRIC CONSIDERATIONS IN LANDFILL STABILIZATION
Moisture Content
One of the parameters of importance to the stabilization processes
occurring in a landfill is the moisture content of the refuse material as
placed. Refuse usually contains a large amount of paper which more than
counteracts any moisture associated witi. garbage and other moist materials.
However, moisture content increases with age and depth mainly because of
infiltration and percolatiorupf rainfall and surface water with time. In
landfill studies by2Eliassen , the moisture content ranged from 18.9 to
3^.3 percent. Merz found a mositure retention of 39-5 gallons per cubic
yard of refuse from which cans and bottles had been removed. However, in
California, rainfall did not penetrate a fill 7-5 feet thick.
The decomposition and stabilization in a landfill is dependent upon
many factors including the moisture content. In general, the rate of chemical
and biological reactions in a landfill increases with increasing moisture
content. In California, where a large amount of water was applied to the fill,
the settlement was abput four times greater than a similar fill without water
addition . Eliassen carried out studies to determine the optimum moisture
content for decomposition of landfill material. The procedure involved adding
given amount^ of moisture to 5-gram, dried samples of refuse. The results
indicated that for fresh landfill material, the optimum moisture content for
biological decomposition ranged between 50 and 70 percent and for older fills
between 30 and 80 percent.
Temperature
Another parameter of considerable significance is temperature. Although
a fill may be placed during cold weather, the material is insulated so that 2
heat is not readily transmitted to the atmosphere. In the study by Eliassen ,
the reactions in the fills were considered thermogenic initially and the tem-
peratures at the depths of 3 and 7 feet w^re between 5°-70°C; at a depth of
11 feet, the temperature ranged between 25-l4.0°C even though the air temperature
was between 10-20°C. These temperatures were in the range between the optimum
temperatures for mesophilic (20-400C) and thermophilic (50-70°c) organisms
and both types of organisms may be presumed to assist in the decomposition of
fill material.
Temperature has been monitored in several simulated landfill studies.
Fungaroli reported a peak temperature of 68°C within the first week of
testing an insulated lysimeter, followed by a slow decline to 6o°C and a
subsequent rapid decrease to a constant 30°C during the remainder of the
study. Sixteen days after placement, Carpenter and Setter reported a
temperature of k8°C at three feet and 55°C at seven feet; the air temperature
was about 2H°C. Temperature recorded after 10 months indicated that the
temperature of the fill had become stabilized at or near air temperature.
Merz and Stone reported the maximum temperatures of two simulated
fills to be 490C and 42°C and that during the final two years of the study,
the temperature ranged from l6°C in the winter to 32°C in the summer in one
-------
fill and from 12°C in the winter to 31°C in the summer in the other.
pH
The chemical and biological reactions occurring in a landfill are a
function of pH. Since these reactions occur primarily within an anaerobic
environment, the pH established during a particular stage of stabilization
is dependent upon the relationship between the volatile acids and alkalinity
in the leachate and carbon dioxide content in the gas evolved from the process.
Therefore, landfill stabilization is very analogous to anaerobic diges-
<=:C>^(
tion
The optimum pH for the anaerobic stabilization process with methane
production as determined by studies on wastewater sludge has been reported
in the range of 6.8 to 7.2 although limits of operation without significant
inhibition have been reported as varying from 6.6 to 7.^- ^ . Dague ^
reported that lime, sodium bicarbonate, sodium hydroxide, potassium hydroxide,
and ammonia may be used to control pH during digestion with the quantity
necessary for neutralization usually below toxic limits.
Published results concerning cation toxicity in the anaerobic digestion
process by McCarty and Kugelman and Chin indicated that alkali and alka-
line-earth cations can be moderately inhibitory at certain ranges of con-
centration. As summarized in Table 2, a concentration defined as moderately
inhibitory were those which normally could be tolerated,
Table 2. STIMULATING AND INHIBITORY CONCENTRATIONS OF ALKALI AND ALKALINE-
EARTH CATIONS TO THE DIGESTION OF SEWAGE SLUDGE
Cation
Sodium
Potassium
Calcium
Magnesium
Stimulatory
100-200
200-UOO
100-200
75-150
Moderately
Inhibitory
3500-5500
2500-4500
2500-^500
1000-1500
Strongly
Inhibitory
8000
12,000
8000
3000
but required some acclimation by the microorganisms. When introduced sud-
denly, the concentrations could be expected to retard the process significantly
for periods ranging from a few days to over a week. Table 2 also includes
ranges where the cations were considered stimulatory and strongly inhibitory.
In addition, Kugelman and ChinJ found that the toxic upper limit for cation
concentrations was 6900 mg/1 for sodium, 5100 mg/1 for potassium, 6000 mg/1
for calcium, and 1580 mg/1 for magnesium.
Dague27 emphasized that the addition of chemicals in order to raise the
pH during digestion may be only a temporary, holding action, and that such
measures will not correct the basic cause of poor methane formation. However,
-------
since the methane formers grow less rapidly than the organisms responsible
for the production of volatile acids, pH control could allow for their develop-
ment before they had been adversely influenced by low pH conditions. As early
as 195^, Sawyer, et al. concluded that, "since it is known that raw sludge
is deficient in buffering capacity, that highly buffered materials are most
resistant to changes in pH, and that natural buffers in digesting sewage
sludge consist of calcium, magnesium and ammonium bicarbonate, it seems
reasonable to conclude that the judicious addition of lime to neutralize
organic acids in order to maintain favorable pH values, will result in a
desirable climate for methane formers, thereby allowing normal digestion to
progress and at the same time adding to the total buffering capacity of the
system." A similar effect could be anticipated for possible control of pH
during landfill stabilization in order to accelerate anaerobic biological
decomposition processes and maximize the rate of methane production.
LANDFILL DESIGN AND OPERATIONAL CRITERIA
Some attempts have been made to include information on leachate charac-
teristics and behavior in design considerations for sanitary landfills.
Hughes suggested several criteria including a thorough knowledge of the
ground water flow system and soil characteristics at the proposed site. The
hydrological and geological suitability of the site could then be ascertained
with respect to retardation of ground water pollution. To preclude per-
colation and leaching, impermeable liners or covers were recommended together
with possible leachate collection with underdrain systems and ultimate dis-
posal. Culham and McHuglr recommended collection and treatment of leachate
from landfills including consideration of filtration, flocculation, and
addition of lime for pH control. The diversion of water from landfill areas
was emphasized as an important method for alleviating leachate problems which
should be included in design and operational procedures. The pollutional
characteristics of leachate also can be attenuated or renovated as it moves
through the underlying earth material before being discharged to the surface
or into the ground water. Emrich recommended one foot of suitable earth
material for every foot of refuse. Anderson and Dorribuslr reported that a
pond and trench located downstream from the slope of the water table improved
the quality of water emanating from a refuse disposal area.
37
Site selection procedures proposed by Cartwright and Sherman included
location of landfills in areas where soils of low permeability exist between
the bottom of the fill and the highest estimated water table. An interim
report on the development of construction and use criteria for sanitary
landfills recommended a geohydrological classification of landfill sites in
addition to reduction of leachate problems by diversion of surface runoff in
lined channels or storm drains, proper grading and use of relatively imper-
vious surface materials, and construction of suitable barriers to restrict
the infiltration of ground water into the landfill. Hughes, e_t al. dis-
cussed the importance of considering stabilization time in selecting sites,
particularly if treatment facilities were planned or if future use of the
site was contemplated. Decrease in stabilization time was considered advan-
tageous when leaching is rapid; permeable cover material and rapid drainage
10
-------
would accelerate leaching and also increase the amount of leachate moving
from the fill. Therefore, the advantage of reducing infiltration into a
landfill would be the reduction of quantity and rate of leachate produced.
However, reduction of infiltration would extend the "polluting life" of the
landfill and if the cover material used had a low permeability, it would tend
to force the gases produced during decomposition laterally rather than upward
through the surface and thereby create potential problems' if gas migration
control was not provided and maintained.
11
-------
SECTION IV
MATERIALS AND METHODS
SIMUIATED LANDFILL CONSTRUCTION
Since the purpose of the research was to develop and study the feasi-
bility of a leachate recycle system to provide leachate treatment and pol-
lution control as well as accelerated rates of biological stabilization within
sanitary landfills, four simulated landfills were constructed on the campus
of the Georgia Institute of Technology in Atlanta, Georgia. The construction
was accomplished in two phases. The two fills of Phase I were completed in
the spring of 1971; the two fills of Phase II were completed in the spring
of 1972. As indicated in Figure 1, all four simulated landfills were basi-
cally similar except for a few modifications instigated during Phase II.
Phase I
The purpose of the initial phase of the study was to demonstrate the
advantages of leachate recycle in accelerating the stabilization processes
within sanitary landfills and in removing readily degradable pollutants from
the leachate. To accomplish this purpose, two simulated landfill columns
were constructed; one with leachate recycle capabilities and the other to be
used as a control without recycle.
The units were constructed Ik feet high by joining sections of 36-inch
diameter AJRMCO corrugated steel pipe. The pipes were lined with two coats
of epoxy paint, placed on a wooden platform, and secured with steel angles
bolted around the base of each column. A conical concrete bottom with a 1.5*
inch drain was formed in each simulated fill to seal the bottom of the pipe
section and facilitate the drainage and collection of leachate. Nine inches
of coarse gravel (3/4 to 2-inch) were placed in the bottom of each column
to prevent clogging by the compacted refuse. The two columns were connected
by cross ties and guyed in two directions for stability.
After the units had been erected, all joints and connections were caulked
with a sealing compound to prevent air from entering the fill by any means
other than from diffusion through the soil cover. Leachate from the simu-
lated landfills was collected in epoxy-lined, 55-gallon drums. A 1.5-inch
ABS plastic pipe provided for drainage of the leachate from the conical base
of the simulated fills into the collection sumps. The drums were covered
to exclude rainfall and other external contaminants.
Initially it was proposed to have proportional sampling device to auto-
matically sample leachate from the sump of the control (non-recycling fill).
12
-------
Note: Wooden Platform is surfaced with 2 x 12 Stock and is
Supported by 4x4 Wooden Posts embedded in 12*of
Concrete.
21-10"
3-8"
4'-10 V2"
3-6"
36 0 Armco Epoxy
Coated Corrugated
Steel Pifre
SlfWlldtGO W«l fW» II ID ff _ I' VII I I**IM »W W h.UIIM I f If w
'/ /' /• r-—• lemperuture " / /*
''(Phase IT) //V \Monitoring Equipment .'• (PhaSC I) »\
211 PVC Plojtic
Pipe and o
Fittings -*
^"Instrument Shed
Discharge
Sumps
5-0
i/f*-l t/2"ABS
Plostic Pipe
and Fittings
4-6
PLAN OF SIMULATED SANITARY LANDFILLS
(NO SCALE)
Leachate Distribution
//System (See Fig. 2)
Compacted Top Soil
1" PVC Recycle Line
1" Pipe Strap
Compacted Refuse
Graded Aggregate
Conical Concrete Base
2" PVC and 1 1/2ABS
Plaslic Pipe and Fillings
Epoxy Cooled Steel Sump
SECTION A-A: RECIRCULATING
SIMULATED LANDFILL
(NO SCALE)
FIGURE 1 SIMULATED SANITARY LANDFILLS
-------
However, due to the small volume and the intermittent nature of the leachate
from this fill, the use of the device was not feasible. Instead, leachate
from the control, Fill 1, was collected in a sealed drain line which was
unplugged only to manually collect a leachate sample.
The leachate collected from the fill with leachate recycle. Fill 2,
was removed from the sump and pumped back through a distributor buried be-
tween the top of the compacted refuse and the soil cover and allowed to
percolate through the refuse (See Figure 1 and Figure 2). An upright float-
operated sump pump (Sears) was used to recycle the leachate to the distri-
bution arm. The drain pipe in the sump was completely submerged in the
leachate at all times by adjusting the float control to cut-off and maintain
the lowest leachate level about 6 inches above the drain discharge.
Three ports were installed in each fill; two for sampling, the third
(center) port contained a temperature probe. The ports were constructed of
0.5-inch galvanized steel pipe lengths inserted through the sides of the fill.
The lengths were secured on both sides of the columns by nuts and rubber
washers and the connections were covered with sealing compound.
Ten feet of compacted simulated refuse were placed in each of the land-
fill columns. The composition indicated in Table 3 was chosen to reflect
that of a typical residential refuse. A total of 2,800 pounds of refuse was
Table 3. COMPOSITION OF SIMULATED REFUSE
Constituent Dry Weight,
Paper
Plastic
Glass
Garbage and Garder
Debri s
Rags
Stone and Sand
Metal
Wood
50.0
3.0
7.0
25.0
5.0
5.0
4.0
1.0
Total 100.0
coarsely ground with a brush chipper and the dry refuse was mixed in 200-
pound batches. The ground refuse was then hauled manually to the top of
the simulated fills and dumped into the columns. The refuse was then manually
compacted to a dry density of about 535 Ib/cu.yd.
A 2-week period was allowed to elapse before the placement of the soil
cover, auring which time the two fills, which were capped to exclude rainfall,
settled approximately 6 inches. Due to this settlement, 30 inches of sandy
clay top soil was manually placed and compacted over the refuse to bring the
total height of each fill to 12 feet.
-------
b
CO
<
— \ «*"
COMPACTS D-^
COVER SOIL
i
J
1^-0"
n-/
J -
o n n n n n o OT
ft ffr/f//tfftf///z(r/^f 3?S/ =
Zjjftsg
.; — 1" PVC DISCHARG
*— 1.5" A BS or 2" PV
/1.5"ABS or 2"P
a
' fun on n niun.i
-1.5"ABSor 2" PVC PIPE
WITH CLOSED ENDS
1/8"SLOTS ON 1" CENTERS
FIGURE 2 LEACHATE DISTRIBUTION SYSTEM
-------
To expedite the production of leachate by the fills, 250 gallons of tap
water were added after the placement of the compacted soil cover. Based on
the moisture holdingcapacity of Timulated refuse reported in other studies,
the addition of 250 gallons of water was considered sufficient to bring the
fills to field capacity. However, since this quantity was applied in a 12-
hour period, some initial short-circuiting resulted; The addition of the
water and the added weight of the cover soil resulted in an additional
settlement of 8.5 and 16.5 inches, respectively, from the total height of
12 feet in the control and leachate recycle fills.
Production of 30 gallons of leachate by both fills after the initial
addition of water indicated that short-circuiting was occurring. Therefore,
to minimize short-circuiting by rainfall, a blanket of sod was placed over
the soil cover to provide better distribution of rainfall across the fill
surface and limit water from flowing down the sides of the fills. Short-
circuiting of recycled leachate was minimized by using a gravity flow dis-
tributor and capping the ends of the distributor pipe to direct the flow
through the center of the fill.
Phase II
The purpose of the second phase of the study was to illustrate the effects
of leachate recycle plus nutrient addition and pH control on stabilization
in sanitary landfills. Therefore, two additional simulated landfills were
constructed with leachate recycle capabilities. The basic columns in Phase II
were identical to those in Phase I (Figure l). However, the leachate drains
in the conical concrete bases were changed from 1.5-inch ABS to 2.0-inch PVC
pipe. The drains from each column discharged into 55-§aHc-n drums which were
equipped with polypropylene liners to provide a more corrosion resistant
container. The sumps for both fills were housed in a metal building (5* x 6' )
which provided cover and also served as an instrument shed.
Leachate recycle was provided as for Phase I except that the distribution
pipe (Figure 2) was increased in diameter from 1.5 to 2.0 inches. This
provided more volume in the pipe and thus reduced the chance of leachate over-
flowing the distributor system.
The refuse used in the Phase II units had the same composition (by
weight) as that used in Phase I (Table 3)» The refuse was coarsely chopped
manually and placed in the columns. The refuse was then again manually com-
pacted to a dry density of about 535 Ib/cu.yd. In one fill, Fill k, 30 gal-
lons of primary sewage sludge was added in three 10-gallon increments while
the refuse was being compacted. To avoid discrepancies, similiarity in
volume of liquid added, an equal volume of tap water was added to the other
column, Fill 3.
To prevent clogging, the distributor was separated from the top of the
refuse by a 3-inch layer of coarse gravel (l to 3-inch). Two feet of soil
cover was added immediately to each unit and rainfall was not excluded. In
order to bring the fills up to field capacity, 220 gallons (30 gallons pre-
viously added by sludge and water) of tap water were added to each fill. In
16
-------
an attempt to minimize short-circuiting, the water was added over a 72-hour
period. Finally, sod was placed on top of the soil cover as in Phase I.
To facilitate the collection of representative refuse samples at periodic
intervals, two sampling ports were installed on each of the new columns. The
ports were constructed by placing a section of 3-inch ABS plastic pipe through
the sides of the columns. The pipes were equipped with threaded plugs and
all joints and connections were caulked with sealing compound.
In each new fill, a 0.75-inch PVC pipe was placed to a depth of five
feet below the sod layer along the side of the corrugated metal pipe. To
this pipe was connected a rubber hose which was directed into a large beaker
of water. The purpose of this pipe-hose-beaker apparatus was to detect and
collect gas for analysis. The sod used for cover in Phase II was identical
to that used in Phase I and was obtained from the same location on the Georgia
Tech campus.
SAMPLING PROCEDURES
Phase I
Samples were obtained from the control fill whenever a sufficient quan-
tity of leachate was produced from rainfall to yield a sample of one to three
liters. When a sufficient volume of leachate had collected in the base of the
control fill, the drain line was opened and the leachate was allowed to flow
into a sampling container. The line was then again closed after all the
leachate had been collected for testing.
A 2l|— hour composite sample was taken from the sump of simulated landfill
with leachate recycle at one to 3-week intervals. An Instrumentation Special-
ties Company Model 780 Automatic Sample Collector was used to obtain 2k, 500-
ml samples which were composited at the end of the sample period (a day). A
1.0-liter aliquot was taken from the composite for analysis. The remainder of
the composite was initially discarded due to the large quantities of leachate
collected from the leachate recycling fill, however, after 30 days of sampling,
residual samples were returned to the collection sump.
Phase II
Samples collected during Phase II of the study were obtained by two dif-
ferent methods. The first method was used for the initial two weeks of the
study and consisted of a grab sample from each of the two sumps; one with the
leachate recycle and pH adjustment (Fill 3) and the other with the leachate
recycle, pH adjustment and initial sludge addition (Fill 4). The second
sampling method employed during the remainder of Phase II consisted of obtain-
ing a 2l).-hour composite sample using an Instrumentation Specialties Company
Model 780 Automatic Sample Collector to remove 500-ml samples from the appro-
priate sump every hour. A 1.0 liter aliquot was taken from the 2*4-hour com-
posite for analysis and the remaining leachate was returned to its appro-
priate sump with none being discarded.
17
-------
In order to manually control the pH of both fills near neutral, sodium
hydroxide (NaOH) was added to each collection sump at various intervals
during the day. The sodium hydroxide was added by two different methods.
During the first nine weeks of the study, a predetermined amount of sodium
hydroxide solution (approximately 150-200 ml) was added to the sumps, mixed,
a 100-ml sample removed, the pH of the sample recorded, and the sample titra-
ted with O.lJf NaOH to a pH of 7.0. Following the titration, the quantity
in grams of sodium hydroxide required to bring the sump volume (17 gallons)
to neutral was calculated. This quantity was weighed, diluted to 150-200
ml with distilled water, and set aside to cool. Six to 2!+ hours later, the
process was again repeated with the addition of the prepared sodium hydroxide
solution.
After the ninth week, the preceding procedure was changed and instead of
placing the caustic solution in the sump prior to removing a sample for a pH
reading and titration, a 100-ml sample was first removed, the pH recorded,
and the sample was titrated with 0.1 N or 0.5 H NaOH solution. Following
the titration, the number of grams of sodium hydroxide required to raise the
sump volume to neutral was calculated, weighed and placed in a flask of 150-
200 ml of distilled water to cool. The solution in the flask was then added
to the sump within a period of less than 2 hours. This change in technique
was instigated as a result of less need for semi-daily neutralization additions
after the ninth week of the study since the pH drop became less drastic with
time and there was the desire to know exactly how the pH had changed each day
after nine weeks of neutralization. After the twelfth week, a Beckman Model
9^0 Automatic pH Controller provided immediate pH control whenever the pH was
not within the optimum range (pH 6.8 to 7.^-).
The apparatus for collecting gas was also used during Phase II of the
study. In order to collect a sample of gas, a clean, two-stopcock Orion gas
sampler was attached to the sampling hose. Both stopcocks were opened for
a period of approximately two minutes, then the one not attached to the hose
was closed. This initial closure was followed by the closure of the stopcock
attached to the sampling hose, thus sealing a sample of gas inside the sampler.
Samples of gas were taken periodically and after the 7th, 12th, 32nd, Wth,
67th, 76th, 84th, 99th and 108th weeks of the study. The gas sampler employed
featured an opening covered with a rubber septum which allowed the removal of
a gas aliquot with a syringe when composition was desired.
Refuse samples of both Fills 3 &nd k were taken at the end of Phase II.
Sampling consisted of removing approximately 700 grams of sample through the
3-inch ports constructed in the side of the two fills.
AHALYTICAL METHODS
Analysis of Simulated Refuse
At the beginning of both Phase I and Phase II, a 2-pound sample of the
simulated refuse was collected and the organic fraction, consisting of paper,
plastics, vegetable matter, meat, rags, and wood, was finely ground in a
18
-------
micromill and analyzed for carbon, hydrogen and nitrogen with a F and M
Model 185 CHN Analyzer. Another portion of the finely ground sample was
digested in concentrated sulfuric acid, neutralized, diluted with distilled
water and analyzed for Kjeldahl nitrogen with a Technicon Auto-Analyzer;
for potassium, sodium, calcium and magnesium with a Perkin-Elmer Atomic
Absorption Spectrophotomejter; and for phosphate using the procedures out-
lined in Standard Methods .
However, phosphate analysis in Phase II was performed using the Techni-
con Auto-Analyzer. In addition, the refuse removed from the simulated land-
fills during both the Phase I and Phase II studies was analyzed for carbon,
hydrogen, and nitrogen using the CHW analyzer, and moisture content and ^Q
volatile solids analyses were performed in accordance with Standard Methods
Analysis of Soil Characteristics
The leaching characteristics of the cover soil used in the Phase I study
were determined and since the same type and quantity of soil was used in
Phase II, additional soil analyses during Phase II were not considered
necessary. The soil was tested by filling two plexiglass columns with 2000
grams of soil similar to that used as cover for the simulated landfills.
The soil was leached with demineralized water to determine the potential
contribution of substances in the cover soil to fill leachate. The leachate
from one soil column was recycled back through the column and the leachate
from the second column was discharged to waste. This allowed for the deter-
mination of the total quantities of iron, calcium, magnesium, manganese,
sodium, ammonia nitrogen, total nitrogen, and total organic carbon (TOG)
leached from the soil and also indicated to some extent the ion exchange
capacity of the soil. The soil leachate was analyzed for sodium, calcium,
magnesium, manganese, and iron with a Perkin-Elmer Atomic Absorption Spectro-
photometer; TOC with a Beckman Total Carbon Analyzer; and nitrogen with a
Technicon Auto-Analyzer.
Analysis of Leachate, Sludge and Gas Samples
leachate samples from the experimental landfills (Phase I and Phase II)
were analyzed for 5-day biochemical oxygen demand (BODj), TOC, chemical
oxygen demand (COD), total suspended solids (TSS), volatile suspended solids
(VSS), total solids (TS), alkalinity, acidity, total hardness, total and
ammonia nitrogen, phosphate, calcium, magnesium, manganese, sodium, iron,
chloride, pH and volatile acids. Similar but fewer tests were initially
conducted on the primary sludge added to Fill k. In addition, samples from
the Phase II study were obtained to determine concentrations of chromium,
copper, zinc, lead, potassium and mickel. During the first 125 days of leach-
ate production in the Phase I study, nitrate determinations were also made
using both specific ion electrodes and colorimetric methods. However, due
to matrix interference difficulties with high concentrations of iron and
chlorides, these results were considered questionable. Therefore, in order
to avoid the problem experienced in Phase I, the Technicon Auto-Analyzer
was used during Phase II to determine nitrate concentration. Sulfates were
also determined during the first 125-day period of Phase I, but since the
19
-------
concentrations were -very low, this analysis was subsequently deleted. In
addition, sulfate analysis was deleted completely from the Phase II study
due to the interference of phosphate on the specific-ion electrode method
used. Moreover, nitrate and sulfate concentrations were converted to their
corresponding reduced states as anaerobic conditions were established and
since it was the main purpose of this research to determine the effect of
leachate recycle, pH adjustment and initial sludge addition on landfill stabi-
lization, these analyses were considered of lesser significance as compared
to the other analytical parameters.
Calcium, magnesium, manganese, sodium, iron, zinc, potassium, chromium,
copper, lead, and nickel were measured with a Perkin-Elmer Atomic Absorption
Spectrophotometer. Phosphates were determined by Hach Kit methods for both
Phase I and II, while the Auto-Analyzer was used to obtain total and ammonia
nitrogen during both test phases. Phosphates were also determined in Phase II
by using the Auto-Analyzer as a comparison to the Hach Kit procedure. Chlo-
rides were measured with an Orion Specific Ion Electrode using the known in-
crement method. Total hardness was calculated from the concentration of
hardness producing cations suggested in Standard Methods . Volatile acids
were measured with the F and M Scientific 700 Chromatograph; pH was determined
with a Leeds and Northrup pH meter; TOG was measured with a Beckman Model
915 Total Organic Carbon Analyzer; and the remaining analyses were performed
according to Standard Methods . Gas samples were analyzed for methane and
carbon dioxide content using a Fisher Gas Partitioner.
20
-------
SECTION V
PRESENTATION OF THE DATA
Results of the analyses performed on the simulated refuse and the leachate
samples of Phase I and Phase II are presented in this section. The time scales
used in this presentation (time since placement of refuse and time leachate
production began) are related in that leachate production began 33 days after
refuse placement in Phase I and seven days after refuse placement in Phase II.
REFUSE COMPOSITION
Analysis of the organic portion (paper, plastic, vegetable matter, meat,
rags and wood) of the refuse used to fill the simulated landfill columns
indicated an initial composition of major constituents as shown in Table h.
Table k. INITIAL COMPOSITION OF THE ORGANIC FRACTION OF THE
SIMULATED REFUSE USED DURING PHASE I AND PHASE II
Refuse
constituent
Composition, percent by weight
Phase I Phase II
Carbon
Hydrogen
Oxygen
Nitrogen
Potassium
Sodium
Phosphorous
Calcium
Magnesium
Volatile Solids
V7.20
5.15
U6.73
0.65
0.12
0.12
0.03
trace
trace
100.00
98.62
U9.50
5.86
^3.68
0.25
0.10
o.59
0.02
trace
trace
100.00
98.32
aOrganic fraction included paper, plastic, vegetable matter, meat, rags
and wood.
The comparisons of the initial composition of the organic fraction of the re-
fuse with the composition of samples taken from the four simulated landfills
at the end of each study period are presented in Table 5.
21
-------
Table 5. CHANGES IN COMPOSITION OP THE ORGANIC FRACTION OF THE SIMULATED
REFUSE FOR EACH TEST UNIT DURING PHASE I AND PHASE II
Refuse Composition, percent by weight
Phase I
Phase II
Refuse
constituent
Carbon
Hydrogen
Oxygen
Nitrogen
Volatile solids
Initial
lt-7.20
5.15
46.73
0.65
98.62
320 daysa
Fill 1
1+6.00
5-97
47.80
90.80
Fill 2
37.00
4.68
57.99
73.00
1063 daysa
Fill 1
89.8
6.5
0.0
88.1
Fill 2
68.2
6.0
—
1.2
65.2
Initial
49.50
5.86
43.68
0.25
98.32
90 daysb
Fill 3
43.20
5.18
50.10
1.52
84.00
Fill 4
42.90
5.20
49.57
2.33
97.91
. b
747 days
Fill 3
80.4
6.2
0.5
80.3
Fill 4
80.3
6.3
—
1.2
84.1
ro
ro
, Refuse sample obtained near surface of columns.
Refuse sample obtained at sampling ports at mid-depth of columns.
-------
COVER SOIL CHARACTERISTICS
To ascertain the relative concentrations of materials potentially con-
tributed to the leachate during operation of the fills, soil leaching studies
were conducted by simulating the operational mode to be used with the test
columns. Figure 3 and Table 6 indicate the results of the leaching column
tests on the cover soil used for each landfill column. Calcium, magnesium,
and sodium were the only cations leached from the cover soil in measurable
quantities with total quantities of 0.0^9, 0.005 and 0.001 mg/gram of soil,
respectively, for the single pass tests. During recirculation, indicated
equilibrium concentrations of 3.U, 0.5 and 1.0 mg/1 respectively for these
cations were obtained. The concentrations of calcium, magnesium and sodium
were initially high but dropped sharply during the first 30 hours of leaching.
As was expected, the concentrations of iron in the leachate were very low.
Graphical integration of the mass flow curves of each element indicated
that the quantity of cover soil on each fill would produce a negligible amount
of each of these elements. Accordingly, the 2.5 feet of cover soil placed
on the top of each fill should leach 58.9 grams of calcium, 11.9 grams of
magnesium, and 1.27 grams of sodium with continuous leaching. The equilibrium
concentrations reached during the leachate recirculation indicated that the
cover soil was a rather poor ion exchange medium for the indicated consti-
tuents. The highest affinity demonstrated by the soil was for calcium with
sodium being held less than calcium but more than magnesium.
LANDFILL TEMPERATURE
landfill temperature during Phase I varied with daily ambient temperature
fluctuations. The maximum (July) temperatures reached were 32°C in the control
fill and 31 °C in the fill with leachate recycle; the minimum (December) temper-
atures were 5°C and h°C, respectively. The temperature variations in the con-
trol fill were slightly more dramatic than in Fill 2 where temperature was also
moderated by the recycled leachate.
To determine whether insulation would provide control of large temperature
fluctuation during extreme temperature periods, the columns were wrapped with
3-inch fiberglass insulation and covered with 4-mil polyethylene plastic to
exclude moisture. After the insulation was placed around the columns, tem-
perature fluctuations were greatly reduced but continued to correspond to
seasonal changes as indicated in Figure k.
Because insulation of the columns was considered beneficial, the simulated
landfills of Phase II were also insulated; after 10 weeks of operation for
Fill 3 and after seven weeks for Fill U. The time of exposure of the fills
without insulation was similar as for Phase I and the moderation of temperature
fluctuations was determined also to be similar. Moreover, the temperature
attained in the fills during the months of May, June, and July when xnsulatxon
23
-------
ro
RECYCLE COLUMN
LEACHING COLUMN
FIGURE 3
TIME .hours
RESULTS OF COVER SOIL LEACHING STUDY
150
o>
cc
h-
z
01
o
o
o
-------
ro
VI
Table 6. RESULTS OF COVER SOIL LEACHING EXPERIMENTS
Single Pass Tests Recirculation Tests
Time,
hours
0
k
7.5
32.5
52.5
72
ikk
Mass flow rate, mg/1
Ca Mg Wa Fe
3.86
3.19
1.68
0.63
0.50
0.50
0.25
0.59
0.50
0.21
o.ok
o.Uo
o.ok
o.ok
0.80
0.76
0.29
0.17
0.08
0.17
0.04
0
o.ok
o.ok
0
0
0.014-
—
Time,
hours
0
2k
k8
72
Ikk
Concentration, mg/1
Ca Mg Na Fe
1.1
1.6
3.3
3.^
3.k
0,1
0.2
0.5
0.5
0.5
0.5
0.5
0.6
1.0
1.0
0.2
0.3
0.2
-__
-------
40
INSULATION INSTALLED
BASED ON APPROXIMATE AVERAGE FLUCTUATIONS
OVER THREE DAY PERIOD
ro
O
o
O
cc
o
UJ
oc
40
30
20
10
MAY, 71
INSULATION INSTALLED
JAN, 72
MAY, 72
JAN, 73
MAY, 73
FIGURE 4 INTERNAL TEMPERATURE FLUCTUATIONS OF THE
SIMULATED LANDFILLS
-------
was not provided during Phase II was considered to be beneficial to the ana-
erobic stabilization process.
LANDFILL SETTLEMENT
The cumulative surface settlement of both Phase I and Phase II fills is
shown in Table 7. As previously mentioned, the fills experienced settlement
due to the placement of cover soil and the initial addition of moisture. For
comparison, this initial settlement was included in the settlement data for
both Phase I and Phase II.
LEACHATE ANALYSIS
Cumulative moisture and precipitation intercepted by the two Phase I fills
are shown in Table 8 and in Table 9 for the two Phase II fills. The total
precipitation intercepted by each fill during Phase I was 235.143 inches in-
cluding the water equivalent of ^6.6 inches initially added to saturate the
fills. During Phase II, the total precipitation was 165.90 inches including
56.6 inches of water and/or sludge equivalent added initially to saturate
the fills. No attempt was made to determine total leachate production which
resulted from the accumulated moisture and precipitation since such an analy-
sis would be influenced by extent of evaporation, quantities of leachate used
during sampling and, for Fills 3 and ^, the liquid additions during neutrali-
zation and pH adjustment.
The concentrations of extracted materials in the leachates obtained from
the simulated landfills of Phase I are tabulated in Tables 10 and 11, while
those materials extracted from the simulated landfills during Phase II are
tabulated in Tables 12 and 13. Changes in concentration are displayed gra-
phically for all four fills in Figures 5 through 20. The concentrations in-
dicated on the figures have been plotted at 30 to 60-day intervals to provide
sufficient data to establish trends and yet avoid excessive clustering of
data points.
Screening analyses for metals including chromium, copper, lead and nickel
were also performed during Phase II but none were found to exist in measurable
quantities in the leachate. These analyses were performed for approximately
the first five weeks of Phase II.
The initial leachate samples taken from the four fills were dark green
in color and had the odor of decaying garbage. The samples from the fills
with leachate recirculation later lost this characteristic color and acquired
a putrid odor characteristic of the short-chained 'organic acids until the
acids were biologically utilized. Upon exposure to air, the color of the con-
trol samples rapidly changed from green to dark brown as the ferrous iron was
oxidized.
27
-------
Table 7. CUMULATIVE SUEFACE SETTLEMENT OF THE SIMULATED LANDFILLS
a
Cumulative Surface Settlement , feet
Time since
leachate
production, days
0
1
2
3
6
8
10
11
13
Ik
17
20
22
2k
27
31
38
50
52
65
72
81
&
117
140
160
180
210
260
280
310
340
1*00
490
580
&0
Phase I Phase II
Fill 1 Fill 2
0
1.70
_ ___
1.99
1.99
1.99
1.98
1.98
____
2.08
2.08
2.15
2.15
2.18
____
_. —
__«_
2.19
2.21
2.22
2.23
2.23
2.24
2.25
2.26
2.27
2.27
____
2.38
2.51
2.61
0
2.40
__--
2.69
__-_
2.69
2.69
___-
2.68
2.68
2.78
2.78
2.85
2.85
2.88
__ —
____
2.89
2.91
2.92
2.93
2.93
2.9!*
2.95
2.96
2.97
2.97
3.08
3-21
3.31
Fill 3
0
2.17
2.17
2.62
2.83
3.04
3.13
3.^2
3.50
3-50
3.63
3.68
3.74
3.81
3.88
3.88
3.88
3.91
3.94
----
__— -.
Fill 4
0
2.67
2.96
3.17
3.33
3.62
3-75
3-92
4.oo
4.00
4.25
4.31
4.31
4.31
4.31
_ — — —
_— *._
alnitial settlement due to addition of cover soil and initial moisture
included.
28
-------
Table 7- (Continued) CUMULATIVE SURFACE SETTLEMENT OF THE SIMULATED
LANDFILLS
Cumulative Suface Settlement , feet
Time since
leachate
production, days
6k9
690
720
7^5
969
1065
Phase I Phase II
Fill 1 Fill 2
2.63
2.67
2.67
2.68
3.33
3-37
3-37
3.38
Fill 3 Fill h
3.95
3.95
U.31
i~3l
a
Initial settlement due to addition of cover soil and initial moisture
included.
29
-------
Table 8. MOISTURE AND PRECIPITATION INTERCEPTED BY SIMULATED
IANDFILLS DURING PHASE I
Time since
placement of
refuse, days
Moisture or
precipitation,
inches
Cumulative moisture
and precipitation,
inches
0
5*
21
27
29
32*
33b
36
38
1*0
45
1*6
47
61
66
70
77
90
124
134
136
165
169
180
19**
197
201*
205
207
221*
227
231
237
21*1
255
267
270
288
307
317
0
0.37
0.68
0.23
1.22
0.37
56.60
0.98
0.18
3.07
1.11
0.98
1.72
1.02
3.70
1.23
1.90
3.50
0.71*
0.86
1.81*
1.85
4.06
1.23
1.81*
3.69
6.15
3.69
2.09
3.12
1.6l
1.21*
1.32
0.36
0.72
2.81
1.12
1.82
2.5l*
0.7k
0
0.37
1.05
1.28
2.50
2.87
59.^7
6o.l*5
6o.64
63.71
64.82
65.80
67.52
7^.54
78.24
79.47
81.37
84.87
85.61
86.47
88.31
90.16
9^.22
95-45
97.29
101.98
108.13
111.82
113.91
117.03
118.64
119.88
121.00
121.36
122.08
121*. 89
126.01
127.83
130.37
131.11
30
-------
Table 8 (continued).
MOISTURE AND PRECIPITATION INTERCEPTED BY
SIMULATED LANDFILLS DURING PHASE I
Time since
placement of
refuse, days
Moisture or
precipitation,
inches
Cumulative moisture
and precipitation,
inches
320
328
335
337
338
351
354
365
366
373
378
381
394
400
4o4
406
433
444
459
468
482
493
498
508
514
520
526
531
536
539
542
543
546
553
561
565
570
583
589
601
0.99
3.92
0.19
0.12
0.37
0.12
0.62
4.8o
0.12
0.62
0.23
0.38
0.84
0.71
1.13
0.24
0.24
o.4o
1.33
1.00
0.34
0.54
2.20
1.20
0.93
0.54
1.36
0.25
0.36
o.i4
0.21
0.20
0.68
2.84
1.31
0.24
2.20
2.10
0.78
0.24
132.10
136.02
136.21
136.33
136.70
136.82
137.44
142.24
142.36
142.98
143.21
143.59
144.43
145.15
146.2?
146.51
146.75
147.15
148.48
149.48
149.92
150.36
152.56
153.76
154.69
155.23
156.59
156.84
157.20
157.34
157.55
157.75
158.43
161.27
162.58
162.82
164.82
166,92
167.70
167.94
31
-------
Table 8. (Continued)
MOISTURE AND PRECIPITATION INTERCEPTED BY
SIMULATED LANDFILLS DURING PHASE I
Time since
placement of
refuse, days
Moisture or
precipitation,
inches
Cumulative moisture
and precipitation,
inches
606
623
627
631
633
639
649
655
659
673
683
697
707
715
721*
745
749
751
756
759
764
769
774
779
786
787
816
819
823
834
837
838
864
868
876
888
892
895
898
909
914
0.35
1.85
0.04
0.44
1.12
2.11*
4.16
0.10
2.60
1.60
0.77
2.29
2.95
0.24
0.89
1.65
0.72
0.53
0.19
0.54
0.06
1.65
0.47
1.07
0.38
0.06
0.90
2.35
0.82
1.13
2.03
0.12
0.27
0.14
0.19
1.64
0.09
0.35
1.65
0.88
0.69
168.29
170.14
170.18
170.72
171.74
173.88
178.04
178.14
180.74
182.30
183.98
186.27
189.22
189.46
190.35
192.00
192.72
193-25
193.44
193.98
194.04
195.69
196.16
197.23
197.61
197.67
196.57
200.92
201.74
202.87
204.90
205.02
205.29
205.43
205.62
207.26
207-35
207.70
209.35
210.23
210.92
32
-------
Table 8. (Continued)
MOISTURE AND PRECIPITATION INTERCEPTED BY
SIMULATED LANDFILLS DURING PHASE I
Time since
placement of
refuse, days
Moisture or
precipitation,
inches
Cumulative moisture
and precipitation,
inches
919
920
923
924
925
926
927
928
929
932
933
93^
936
939
944
948
949
950
951
952
953
95^
958
964
965
970
971
972
975
978
1003
1005
1011
1013
1014
1017
1019
1023
1028
1029
1037
0.03
1.35
0.87
0.09
2.42
0.06
0.36
0.51
0.17
0.18
0.14
0.22
0.22
0.26
0.91
0.38
0.04
0.35
0.33
0.25
0.23
o.o4
0.21
2.05
0.59
1.38
1.26
0.05
0.34
0.67
0.55
0.39
0.20
0.82
0.33
0.67
1.53
0.59
0.40
0.12
0.63
210.95
212 . 30
213.17
213.26
215.68
215.74
216.10
216.61
216.78
216.96
217.10
217.32
217.5^
217.80
218.71
219.09
219.13
219.48
219.81
220.06
220.29
220.33
220.54
222 . 59
223.18
224.56
225.82
225.87
226.21
226.88
227.43
227.82
228.08
228.84
229.17
229.84
231.37
231.96
232.36
232.48
233.11
33
-------
Table 8. (Continued)
MOISTURE AND PRECIPITATION INTERCEPTED BY
SIMULATED LANDFILLS DURING PHASE I
Time since
placement of
refuse, days
Moisture or
precipitation,
inches
Cumulative moisture
and precipitation,
inches
ic4?
1053
105^
1055
1056
1057
1060
0.0?
0.30
0.02
0.38
0.55
0.57
0.1*3
233-18
233. U8
233.50
233.88
23^ A3
235.00
235.^3
, Fills were capped until 5 days after refuse was placed.
250 gal. of tap water initially added to each fill.
-------
Table 9. MOISTURE AND PRECIPITATION INTERCEPTED BY SIMULATED
LANDFILLS DURING PHASE II
Time since
placement of
refuse, days
Moisture or
precipitation,
inches
Cumulative moisture
and precipitation,
inches
0
1
5
6
7
10
12
18
25
27
28
4l
ho
cjii
55
62
67
70
83
89
93
95
122
133
148
157
171
182
189
197
203
209
214
220
225
0
2.26
23.75*
15.83
8.66C
o 98
8*.66C
3.92
0.19
0.12
0.37
0.12
0.62
4.8o
0.12
0.62
0.23
0.38
0.84
0.71d
2.32
0.24
0.24
o.4o
1.33
1.00
0.34
0.5k
2.20
1.20
0.93
0.54
1.36
0.25
0.36
0
2.26
26.01
4i.84
50.50
51.48
60. 14
64.06
64.25
64.37
64.74
64.86
65.48
70.28
70.4o
71.02
71.25
71.63
72.47
73.18
75-50
75.74
75-98
76.38
77.71
78.71
79-05
79.59
81.79
82.99
83.92
84.46
85.82
86.07
86.43
b
c
d
105 gallons of tap water added to each fill; includes 30 gallons of
sludge equivalent initially added to Fill 4.
70 gallons of tap water added to each fill.
35 gallons of tap water added to each fill; includes natural rainfall.
5 gallons of tap water added to each fill; includes natural rainfall.
35
-------
Table 9. (Continued)
MOISTURE AND PRECIPITATION INTERCEPTED BY
SIMULATED LANDFILLS DURING PHASE II
Time since
placement of
refuse, days
Moisture or
precipitation,
inches
Cumulative moisture
and precipitation,
inches
228
231
232
235
2U2
250
25U
259
272
278
290
295
312
316
321
322
328
338
3^8
362
372
377
386
396
hoh
1+13
l|3l|
h^B
1*0
1*7
U52
^57
ii66
^73
501
50l*
508
0.1*4-
0.21
0.20
0.68
1.31
0.2U
2.20
2.10
0.78
0.2k
0.35
1.85
o.oU
1.12
2.1U
0.10
2.60
1.60
0.91
0.77
2.29
2.95
0.2U
0.89
1.65
0.72
0.53
0.19
0.5^
0.06
1,65
O.U7
1.07
0.38
0.06
0.90
2.35
0.82
86.57
86.78
86.98
87.66
90.50
91.81
92.05
9^-25
96.35
97-13
97-37
97.72
99.57
99-61
100.05
101.17
103.31
107. V7
107-57
110.17
111.77
112.68
113*5
116.7^
119.69
119-93
120.82
122*7
123.19
123.72
123.91
121*-. 51
126.16
126.63
127.70
128.08
128. Ill
129. oil
131.39
132.21
36
-------
Table 9. (Continued)
MOISTURE AND PRECIPITATION INTERCEPTED BY
SIMULATED LANDFILLS DURING PHASE II
Time since
placement of
refuse, days
Moisture or
precipitation,
inches
Cumulative moisture
and precipitation,
inche s
522
525
526
552
556
576
580
583
587
598
603
608
609
612
613
615
-*~^
616
617
618
621
622
623
625
628
we. w
633
637
638
639
64o
642
643
• ^J
647
653
654
659
660
66l
664
667
1.13
2.03
0.12
0.27
0.14
0.19
1.64
0.09
0.35
1.65
0.88
0.69
0.03
1.35
0.87
0.09
2.42
0.06
0.36
0.51
0.17
0.18
0.14
0.22
0.22
0.26
0.91
0.38
0.04
0.35
0.33
0.25
0.23
0.04
0.21
2.05
0.59
1.38
1.26
0.05
0.34
0.67
133-34
135.37
135.49
135.76
135.90
136.09
137-73
137.82
138.17
139.82
140.7
141.39
l4l.42
142.77
l43 . 64
143.73
146.15
146.21
146.57
147.08
147.25
147 . 43
147.57
147.79
148.01
148.27
149.18
149. 56
l49.6o
149-95
150.28
150.53
150.76
150.80
151.01
153-06
153.65
155.03
156.29
156.34
156.68
157.35
37
-------
Table 9. (Continued)
MOISTURE AND PRECIPITATION INTERCEPTED BY
SIMULATED LANDFILLS DURING PHASE II
Time since
placement of
refuse, days
Moisture or
precipitation,
inches
Cumulative moisture
and precipitation,
inches
692
694
700
702
703
706
708
712
717
718
726
736
742
743
744
745
746
749
0.55
0.39
0.20
0.82
0.33
0.67
1.53
0.59
0.1*0
0.12
0.63
0.07
0.30
0.02
0.38
0.55
0.57
0.43
157.90
158.29
158.49
159.31
159.64
160.31
161.84
162.43
162.83
162.95
163.58
163.65
163.95
163.97
164.35
164.90
165.47
165.90
38
-------
Table 10. CONCENTRATIONS OF EXTRACTED MATERIAL IN LEACHATE OBTAINED FROM CONTROL LANDFILL ( FILL 1)
Time Since Leachate
Production Began, days
1U
24
32
39
1*8 81 116 125 153 173 189 197 228 2l*9 281* 312 332 31*7 398 428 1*73 506
COD, mg/1
BOD5> mg/1
TOC, mg/1
TSS, mg/1
VSS, mg/1
TS, mg/1
Total Alkalinity, mg/1 as CaCO
Total Acidity, mg/1 as CaCO
pH
Total Hardness, mg/1 as CaCO
Acetic Acid, mg/1
Propionic Acid, mg/1
Butyric Acid, mg/1
Valeric Acid, mg/1
Phosphate, mg/1 P<3^
Organic Nitrogen, rag/1 as N
Ammonia Nitrogen, mg/1 as N
Chloride, mg/1
Sulf ate , mg/1 SOi,
Calcium, mg/1
Magnesium, mg/1
Manganese, mg/1
Sodium, mg/1
Iron, mg/1
Total Volatile Acids, mg/1 as
Acetic Acid
4,320
2,500
1,230
125
45
2,442
558
690
5.2
450
500
369
110
Nil
26
56
56
1 Q "i
-IO • J
322
84
1?5
26
3
63.8
9
874
9,150
5,000
1,910
34
20
5,819
1,610
1,100
5.6
1,400
2,111
1,595
965
425
3-0
47
150
385
126
430
71.8
10
125
21
4,310
10,380
9,200
2,622
59
47
6,323
1,640
1,350
5-3
1,850
2,360
1,834
1,075
575
5.0
61.4
167.6
109.8
108
470
67
5
132
70
4,925
10,260
6,330
2,622
61
52
8,3OO
1,920
l,4oo
5.3
1,810
2,664
2,038
1,050
625
7.8
62
187
84
105.1
8l
590
75
6.2
132
30
5,399
12,000
11,000
2,802
1*7
37.6
8,736
2,280
1,780
5.3
1,940
3,666
2,313
1,280
535
2.8
75
185
1 T C
J..1?
77.9
i Rf>
ipo
750
68
8.8
143
95
6,721
11,700
8,200
2,835
213
93
6,789
2,110
2,170
5.3
1,754
3,268
2,108
1,164
612
2.9
48
192
340
1 V
-L I
545
64
8.5
150
65
6,133
9,200
8,800
2,864
270
]6o
5,530
2,420
1,836
5.7
1,410
2,789
1,875
1,000
643
3-3
40
148
2
430
52
10
180
60
5,370
10,100
9,600
2,259
64o
332
7,250
2,650
1,390
5.3
1,429
3,285
2,625
1,203
893
4.2
177
103
Q S
7*J
170
7
375
49
7.5
118
155
6,750
11,700
8,700
2,418
550
31'
7,358
2,120
2,090
5.2
1,694
2,590
2,110
1,424
656
3."*
64
130
12
240
1
420
53
10
135
230
5,655
12,200
11,100
2,680
292
182
7,620
2,350
2,230
5.3
2,232
3,280
2,290
1,195
708
2.8
6
260
210
16
600
80
16
155
200
6,370
12,300
9,200
2,696
470
268
7,875
2,100
2,780
5.1
2,354
3,440
2,190
1,215
652
1.7
20
214
208
578
85
14
154
300
6,420
14,400
12,ooo
3,049
360
210
8,320
2,482
2,865
5.2
2,306
3,393
2,400
1,350
730
1.6
12
218
312
565
35
15
155
290
6,693
15,600
9,300
3,4o
17
104
8,130
1,760
3,260
5.1
2,449
3,550
2,214
1,750
801
1-5
43
264
308
545
75
16
148
420
7,000
18,100
13,400
5,000
85
"6
12,500
2,480
3,460
5.1
5,555
5,160
2,840
1,830
1,000
1.3
107
117
180
1,250
260
18
160
185
9,300
15,6OC
12,600
3,590
17
14
8,780
1,580
2,610
5.2
3,463
3,754
1,742
1,770
705
1.5
116
52
300
850
210
19
140
250
6,785
13,300
9,560
3,000
60
28
7,716
2,430
2,000
5.2
2,424
3,460
1,640
1,800
750
0.9
76
110
280
550
90
12
85
370
6,460
13,800
8,800
2,93
61
28
7,167
1,93
2,400
5.3
2,299
2,830
1,580
1,740
768
1.1
63
103
295
490
65
12
l4o
440
5,745
--
--
3,18
308
146
6,965
1,960
3,360
5.3
1,622
2,275
1,380
1,540
590
.6
28
152
124
433
40
19
103
190
,795
11,100
7,75
3,00
88
1*3
6,260
1,72
3,460
5.2
1,326
2,210
1,330
1,460
560
.40
40
132
137
385
53
11
110
70
4,615
9,000
5,300
2,43
1,24
602
5,602
1,500
1,95
5.3
1,576
1,000
720
970
855
1
124
88
6.4
143
350
39
10
130
292
,745
9,500
6,500
2,91
800
400
5,800
1,75
2,100
5.60
1,840
2,410
1,100
940
710
0.51
48
88
.09
150
400
45
15
130
240
1
8,950
6,050
2,910
680
470
3,750
2,040
1,710
5.68
1,580
2,520
1,520
500
395
0.51
46
86
.07
130
350
45
6.5
145
280
,325
3,050
6,600
2,665
800
310
3,650
2,040
1,440
5.90
1,310
2,220
1,260
704
428
0.27
42
80
.07
164
230
12
7.5
130
295
,974
U)
vo
-------
Table 10 .'continued). CONCEHTRATIONS 0? EXTRACTED MATERIALS IB LEACHATES OBTAINED FROM CONTROL LANDFILL (flU. 1)
Tin Since LeacUate
Production Began, day*
530 556 606 636 672 70U 758 785 820 858 87* 895 899 968 *9 96U 972 979 993 1007 1028 10U2 1063
COD, ng/1
BOD5, mg/1
TOO, mg/1
TSS, ng/1
VSS, ng/1
TS, mg/i
Total Alkalinity, ag/1 aa CaCOj
Total Acidity, mg/1 a* CaCOj
pH
Total Hardness, mg/1 ai CaCO,
Acetid Acid, mg/1
Propionic Acid, ng/1
Butyric Acid, ng/1
Valeric Acid, ng/1
Phosphate, ng/1 PC^*
Organic Nitrogen, ng/1 ai N
Amonii Nitrogen, ng/1 a* N
Nitrate Nitrogen, ng/1 HO^
Chloride, ng/1
Sulfate, ng/1 So]j
Calcium, ng/1
Magnesium, ng/1
Manganese, ng/1
Sodium, mg/1
Iron, ng/1
Zinc, mg/1
Total Volatile Acia», mg/1 a«
Acetic Acid
7,81.5
U.800
2,127
5Uo
3UO
2,1425
1,970
1.8UO
5-95
1,190
2,750
720
nu
teo
0.29
85
35
.07
1ft
2OO
22
3.5
lUo
280
...
U.068
6,210
3,835
2,1.10
1,170
380
2.UOO
2.0UO
1,670
6.10
1,170
2,920
1*00
90
70
0.23
87
28
.06
200
175
22
U.
170
27
"42.
3,300
6,120
U.300
1,400
1,010
300
2,100
2, QUO
1,670
6.00
1,160
2,910
UlO
UO
30
0.32
85
19
.17
13*
155
20
U.5
275
270
3,28
6,lUo
U.200
2,090
510
210
2,050
1,800
2,350
6.10
1.8UO
1,750
1,200
UlO
395
0.26
59
8
.OU
13U
lUo
20
3.5
235
250
3,23
5,750
b,300
2,190
750
305
2,loo
Z.OUO
1 7UO
6.20
790
1,750
1,100
too
395
0.27
16
8
.OU
85
110
11
U.5
235
2U5
3,1U
,990
,350
,990
750
310
,1OO
,2Uo
i.fto
6.30
750
1,550
1,150
Uoo
200
0.26
26
12
• 15
110
1U2
12
2.5
210
2UO
2,87
^y>
,090
,096
3Uo
200
1,360
860
5.8
1,192
1,000
300
250
30
1.2
25
13
.OU
200
150
22
4.5
50
too
1,1.31
,560
,250
,158
300
190
1,012
1,226
6.05
1,396
1,100
320
270
30
0.9
26
10
•05
115
160
22
1..6
Wt
500
1,56
,788
,85".
,018
152
106
8W>
1,059
6.10
1,538
1,000
350
125
20
0.7
27
lit
.03
105
215
2U
3.5
50
500
1,38
,210
,1.50
,100
200
63
1,011.
908
6.35
1.3U8
1,250
300
100
10
1.0
27
11
.08
86
175
2l»
3.5
"»5
U50
1,567
,560
,ifco
,050
13>»
65
887
1,000
6.1.
1.3U8
750
250
50
t
1.1
22
^
.<*
86
175
2U
3-2
1*3
U50
12
990
,250
,100
,ouo
...
...
,265
887
6.U5
1,305
—
...
...
—
0.8
23
„
.<&
88
175
2U
l».0
1.5
tes
10
--
,725
,015
,160
19E
100
995
832
6.12
1,1(01
930
381.
250
262
0.5
15.0
9.0
0.08
27
175.0
21. 7
7.5
Uo.o
325
10.0
1,565
,890
,?15
,600
57
U7
,030
,<*0
5.80
A50
,teo
1.50
386
119
1.2
13.5
7.5
0.21
29
187.5
26.2
17.5
37.5
325
30.
3,117
,530
,*»
,960
Ul
27
,1WO
1,273
5.60
1,807
1,955
U*
teB
179
1.1
15.5
U.5
0.02
U2
192.5
19.5
13.75
32.5
U63
33-8
2,752
,125
,915
,080
151
82
,065
,300
5-30
1,797
,160
UU2
U36
132
1.0
15.0
6.0
0.2U
28
1U5.0
21.7
13.00
25.0
500
31-3
!,893
,680
,305
,000
16
16
960
,300
5.25
1,966
1,822
U23
U23
123
0.9
13.5
U.5
0.12
28
111.0
18.
11.70
22.
600
21.
?,52
,U80
,9UO
,600
18
18
995
1,300
5.UO
1,501
1,338
308
3lU
95
1.3
lU.o
2.0
0.10
29
90.0
16.2
15.00
17.
U50
13-
1,857
,653
,170
,760
39
39
850
,080
5.60
1,602
1,352
321
302
95
1.0
12.5
3.5
0.12
30
100.
17.
11.20
22.5
U75
17.0
1,871.
,l80
,020
,550
Ul
36
815
,090
5.80
,567
,035
U15
303
lUo
O.U5
8.9
1.1
0.18
22
90.0
15.0
8.75
21.2
*75
12.5
1,659
,580
,280
,838
U8
Ul
870
,080
5-90
,850
835
368
2UU
7U
3-2
9.5
1.5
0.09
26
65.0
17.5
3.80
18.8
600
10.0
1,353
,uoo
,550
,813
50
Uo
670
,2UO
5.70
1.7W.
970
UUO
275
123
1-9
9.9
l.l
0.10
22
65.0
15.5
5.90
18.8
56U
13-8
1,585
,175
,937
,920
36
25
760
,290
5.80
,5U2
1,330
U76
1.96
138
2.0
lU.O
f 0
0.16
30
112.0
20.0
5.UO
15.
^38
18.
!,13
o
-------
Table 11. CONCENTRATIONS OF EXTRACTED MATERIALS IK LEACHATE OBTAINED FROM HECIRCUIATING IANDFILL (FILL 2)
Tljne Since Leachate
Production Began, days
18
21*
31
39
58 67 96 111 126 11*0 161 189 197 219 228 2l*9 Z&\ 281* 312 332
COD, mg/1
IOD , mg/1
•roc, mB/i
TSS, mg/1
VSS, mg/1
TS, ng/1
Total Alkalinity, ng/1 as CaCO
Total Acidity, mg/1 as CaCO
pH
Total Hardness, mg/1 as CaCO.
Acetic Acid, mg/1
Propionic Acid, mg/1
Butyric Acid, mg/1
Valeric Acid, mg/1
Phosphate, mg/1 PoJ
Organic Nitrogen, mg/1 as N
Ammonia Nitrogen, mg/1 as N
Nitrate Nitrogen, mg/1 NO"
Chloride, mg/1
Sulfate, mg/1 SOjj
Calcium, mg/1
Magnesium, mg/1
Manganese, mg/1
Sodium, mg/1
Iron, mg/1
Total Volatile Acids, mg/1 as
as Acetic Acid
li,280
S750
-',130
93
22,5
2,31*9
302
55>»
5.05
370
1,638
960
1,300
500
22
20
70
6.2
210
102
60
16.5
1*
61.5
!*.!*
3,605
9,288
,200
1,020
13.6
...
14,329
700
1,900
It. 8
895
556
39U
235
735
1-5
30
68
71 A
210
138
315
59
30
109
19.5
1,1*65
8,870
6,900
2,260
12
9
1*,552
865
1,51*0
5.0
380
2,000
1,21*2
1,235
50
2.1
30
113,5
56.6
21*8
81
350
53.5
50
8l.lt
19
3,875
9,080
6,800
a.OHO
36.5
27.5
5,023
1,080
1,350
5.1
1,010
1,81*3
1,1*67
1,163
833
0.65
1*05
86.5
76.6
*. 5
51
1*35
62.5
65
91.1*
80
1*,315
8,111
it, 300
2,391*
70.5
1*5'
5,1*00
1,200
1,000
5.3
890
1,^75
1,551*
1,375
688
0.81
37 5
77.5
1*8
91
30
It20
56
62
85
"t3
1*,080
7,700
5,1*00
1,818
25
18.8
1*,728
1,370
1,390
5.1*
i,oUo
1,583
1,59"*
1,250
670
0.67
39 5
76.5
1*9
115
12
1*30
56
62
81*
110
1*,120
8,H*o
6,202
2,665
37.0
16.9
It, 9l*l
1,525
1,265
5.3
1,222
1,795
1,580
1,200
711*
0.82
Itl
61*
11 0
220
11
It20
50
75
95
25
l*,315
9,580
6,1*00
2,000
120
70
5,250
1,1*38
1,530
5.3
1,1*83
2,11*6
1,752
1,198
800
0.85
30
69
11 5
161*
Nil
1*15
50
75
85
35
M55
10,1*00
6,380
2,675
301
161
5,1*1*0
1,035
1,765
5.1
1,532
2,1*38
1,953
1,901*
858
0.96
39
81
12 .0
176
12
1*1*0
53
80
88
Uo
5,825
10,025
7,200
2,796
11*3
78
5,960
1,900
1,798
5.1*
1,701
2,71*2
2,203
1,156
857
0.65
62
81*
16 £
ll*0
2
500
55
80
90
1*5
5,815
10,500
8,700
1,990
222
158
5,830
2,350
1,730
5-5
1,987
2,1*38
1,953
1,01*7
786
0.38
92
80
21.0
188
1
550
62
85
98
110
5,195
10,500
8,500
1,979
258
11*2
6,918
1,61*0
1,830
5-3
1,1*95
2,1*70
1,865
1,121*
81*2
0.50
228
71
ll».0
170
3
385
1*1*
60
70
150
5,21*5
10,350
10,100
1,952
385
188
6,106
1,670
1,700
5.3
2,296
2,380
2,020
937
625
0.39
7
135
210
600
70
93
81*
150
5,025
8,890
9,U05
1,51*2
187
113
5,336
1,61*0
1,630
5.2
1,91*8
1,877
1,1*72
735
556
0.82
3
126
236
"t75
60
80
75
210
3,895
5,810
6,650
1,280
232
156
It, 090
1,550
500
6.3
1,1*69
2,925
1,995
665
585
O.lt7
1*
80
300
1*OO
50
59
61
90
5,31*0
l*,270
3,500
1,067
220
lib
3,967
1,31*2
333
6.6
1,11*6
60S
71>*
286
276
0.26
Nil
62
270
3l*0
1*5
50
59
13
1,545
3,550
2,860
911*
131
76
3,21*0
1,115
2UO
6.8
978
731*
195
191*
87
0.2U
Nil
56
260
290
1*0
W*
50
5
1,075
2,970
1,1*00
710
122
7>t
2,792
952
180
6.9
677
770
111
68
65
0.07
1
39
2U8
190
1*0
19
60
l.i.
9U5
2,81*0
2,500
565
11*5
87
2,370
980
166
7.0
539
670
10U
6?
50
0.08
3
31
221*
11*5
38
10
55
1.9
830
2,580
2,1*20
500
121*
56
2,510
925
133
7.1
661
111
57
Nil
Nil
0.09
2
35
220
175
1*0
19
60
ll*
155
1,950
760
308
67
37
1,81*8
738
8U
7.U
513
23!*
223
62
35
0.12
1
27
218
135
35
1U
55
1*
U75
1,280
760
256
305
18
1,627
6ge
80
7.3
377
365
110
1*1*
Nil
0.09
7
13
202
82
38
8
75
1.2
1*85
1,050
5l*0
1*80
538
1*1
1,784
800
152
.7.1
11*6
1*00
160
20
13
,03
Hll
30
119
115
32
3
53
5
555
-------
Table 11. (continued). COMCEMTRATION8 OF MATERIALS IN LEACHATBS OBTAIMED FROM RECIRCUIATION LAHDFILL (FILL 2)
Time Since Leacnate
Production Began, dayc
366
396 1*28 1*73 506
530
556 606 636 672 7(A 758 785 820 8U3 89!* 882 899 928 961* 993 .1028 1063
CCO, ng/1
BOD , mg/1
TOO. «g/J
IBS, mg/1
VSS, mg/1
TS, Bg/1
Total Alkalinity, Bg/1 as C«CO,
Total Acidity, mg/1 as CaCO.
PH
Total Hardness, mg/1 as CaCO
Acetic Acid, Kg/1
Fropionlc Acid, mg/1
Butyric Acid, mg/1
Valeric Acid, mg/1
Phosphate, rag/1 PoJ*
Organic nitrogen, mg/1 ai N
Ammonia Nitrogen, mg/1 as N
Nitrate Nitrogen, mg/1 NO*
Choloride, mg/1
Sulfate. mg/1 SO*
Calcium, mg/1
Magnesium, mg/1
Manganese, mg/1
Sodium, mg/1
Iron, mg/1
Total Volatile Acidi, ng/1 as
Acetic Acid
1,110
700
1*75
370
69
2,038
780
200
6.91
520
525
120
26
33
.15
16
26
—
116
136
3U
8
63
lit
660
800
510
5^5
1*05
72
...
800
250
6.90
—
1,050
55
95
180
.09
—
—
—
...
...
—
...
...
—
1,265
870
1*0
510
350
50
2,100
800
250
6.90
375
1,110
70
110
170
.08
3
18
.09
158
1*0
30
8
60
0
1.3U2
U90
26I>
515
310
100
2,800
81*0
250
£.82
250
1,000
90
120
11*5
.08
It
15
.01*
20U
25
1U
10
70
0
1,21*0
225
320
375
250
90
2,000
8i«o
250
7.10
200
875
1*0
20
50
.05
6.5
3-5
.08
236
27
13
0
1*0
0
955
258
85
325
ll*0
110
820
780
230
6.95
200
9UO
38
UO
70
.06
1U
0
.06
176
27
12
0
60
0
1,039
192
75
310
ll*0
80
720
760
21*0
7.05
170
865
1*2
1*0
60
.05
7
0
.01*
150
11
11
.1*
100
0
961
113
1*6
325
510
280
950
620
260
6.1*5
no
71*0
75
75
85
.06
0
0
.05
UO
11
11
.1
120
0
90S
56
1*1*
520
1*00
250
900
8UO
110
7.0
100
1*10
75
120
20
.10
0
0
.05
76
9
10
.2
120
0
56U
81*
"*5
3^5
310
110
850
880
180
7.10
90
11*0
35
30
10
.05
0
0
.05
70
9
11
0
020
0
19U
70
1*1*
250
200
70
700
8UO
11*0
7.0
105
75
35
0
0
.07
0
0
.05
70
9
10
0
120
0
103
113
1*2
1*6
...
1,120
50
7.1
60
0
0
0
1.0
3
0
.1
69
125
20
...
1*8
...
60
99
21*
1*0
22
6
Uoi
115
6.8
—
—
—
...
.1*
3
0
.06
69
162
18
2.5
1*2
15
...
20
32
25
5
1*97
168
6.5
—
—
—
—
-5
5
0
,2U
73
125
18
1.0
52
10
33
.26
—
36
6
1*31*
38
7.2
50
0
0
0
.It
3
0
.03
55
WO
15
2.8
30
1*
50
>»3
—
30
20
1*
380
1*7
7.05
—
—
—
—
.3
3
0
.03
55
...
.5
*3
...
1*5
16
25
...
...
362
56
7.15
60
0
0
0
.5
3
0
.08
—
100
15
.6
U3
3
60
102
23
70
26
25
1*17
56
6.78
281*
595
92
U7
12
0.7
3.0
0.0
0.08
1*0
85.0
15.7
1.3
27.5
3.0
709
78
31
30
30
29
398
65
6.60
21*7
208
3*
12
0
O.U
1.0
0.0
O.Ol*
26
77.5
11.7
1.0
22.5
2.0
21*1*
61
29
50
23
23
1*16
100
6.50
291
167
25
12
0
0.5
1.0
0.0
0.09
37
90.0
13-2
0.95
26.8
"t.5
195
80
32
100
39
88
398
85
7.00
237
125
17
6
0
0.5
2.5
0.5
0.16
30
70.0
11.2
0.95
22.5
6.0
ll»3
67
28
212
26
26
1*16
100
6.80
217
300
159
21*
0
O.U
.15
0.5
0.10
28
65.0
11.2
0.1*0
20.2
3.5
1*1*5
79
39
1*20
17
16
1*17
110
6.80
239
31U
U30
1(A
00
O.I*
1.5
0.5
0.16
30
70.0
12.5
0.50
16.2
5.0
733
ro
-------
Table 12. CONCENTRATION OF EXTRACTED MATERIALS IN LEACHATE OBTAINED FROM FILL 3
Tine Since Leachate
Production Began, days
17
31
38
1*5 52
68
73
80
87
111*
13lt 156 169 183 206 221
COD, mg/1
BOD5> mg/1
TOC, mg/1
TSS, mg/1
VSS, mg/1
TS, mg/1
Total Alkalinity, mg/1 as CaCO
Total Acidity, mg/1 as CaCO-
PH
Total Hardness, mg/1 as CaCO.,
Acetic Acid, mg/1
Propionic Acid, mg/1
Butyric Acid, mg/1
Valeric Acid, mg/1
Phosphate, mg/1 as PO.
Organic Nitrogen, mg/1 as N
Ammonia Nitrogen, mg/1 as N
Nitrate Nitrogen, mg/1 as NO,
Chloride, mg/1
Calcium, mg/1
Magnesium, mg/1
Manganese, mg/1
Sodium, mg/1
Iron, mg/1
Potassium, mg/1
Zinc, mg/1
Total Volatile Acid, mg/1 as
Acetic Acid
5,850
l*,150
1,975
—
...
...
1,500
325
6.61
...
950
1*1*0
175
0
3-9
...
—
...
...
...
—
...
—
—
—
—
1,1*25
6,900
3,900
2,360
126
78
3,896
1,870
1*85
6.52
537
1,575
1,11*0
800
25
...
92
325
5-3
191
136
31
10
182
1*2
...
3,060
7,600
U, 1*00
2,31*0
253
11*1.
lt,7l»5
2,530
830
6.28
790
1,810
1,1*60
765
130
0.22
».5
1*13
!*.!»
251*
205
38
19
21*8
53
...
—
3,587
9,050
6,600
2,610
281
ll*2
5,206
2,830
860
6.50
863
1,825
1,235
738
200
0.10
1*
1*27
3-5
252
230
1*0
19
336
50
690
0.8
3,1*50
9,200
7,150
2,375
1*01
171
6,219
2,710
930
6.32
997
2,250
1,275
825
225
0.26
30
392
l*.0
253
270
1*1*
19
630
91
7*0
0.8
3,975
9,700
6,800
2,660
371*
161
6,811
2,660
630
6.31*
1,01*3
2,350
1,360
1,000
300
1.20
26
U37
l*.2
316
275
1*6
19
600
68
...
—
l*,305
9,1*00
6,800
2,1*85
569
250
7,756
3,220
835
6.30
1,1*05
2,065
2,600
1,01*0
395
1.50
92
396
3-5
305
390
55
15
750
80
500
0.6
5,105
8.7OO
5,200
2,310
880
ll*0
5,678
2,71*0
550
6.81
1,055
380
2,260
665
385
0.25
67
3"*3
3-1
293
285
50
19
613
17U
392
1.3
2,890
7,200
5,'*00
2,370
...
...
6,012
2,91*0
6Uo
6.69
61*2
272
2,620
H*5
260
0.29
111*
30U
1.9
287
165
53
6
625
100
31*5
0.8
2,61*5
7,950
5,900
2,1*00
978
226
6,135
2,780
500
6.61
81*7
220
3,580
320
1*1*0
0.29
67
268
2.0
290
220
63
8
1,050
160
360
0.8
3,600
8,200
5,600
2,060
926
21*1*
6,531*
2,5UO
560
6.19
896
1,230
2,970
95
nil
—
55
260
0.6
331
225
67
11*
800
18
385
1.3
3,695
7,875
I*,600
2,055
7U7
175
6,912
U.360
550
6.88
1,057
900
2,1*30
nil
100
0.18
50
2l*U
0.6
321*
230
67
1U
825
100
1*00
1.0
2,930
7,075
5,300
1,900
l,06o
251
6,387
3,150
1*00
7.00
1*92
1,1*10
2,650
50
100
0.27
1*6
176
0.5
307
80
36
23
1*00
57
231
0.6
3,652
1,860
1,1*00
1,650
1*70
ll*0
5,1*00
2,960
1*10
7.10
21*0
1,160
2,000
50
120
0.1*2
5"*
216
0.23
330
80
1*5
17
560
25
235
1.0
2,885
950
860
815
1*50
ll*0
3,800
2,680
1*00
7.20
210
1,120
350
50
90
0.37
1*3
221*
0.17
300
2.3
1*0
21
520
12
3l*0
0
1,1*95
850
500
7>*5
1*80
130
U.200
2,660
1*00
7.1*5
205
1,000
250
1*0
75
0.22
25
192
0.17
380
2A
25-5
25
500
8
31*0
0.02
1,27"*
81*0
367
660
510
120
3,1*00
2,620
360
7.30
180
6i*o
1*2
25
50
0.30
58
176
0.15
380
2.6
16
6.5
1*90
8
31*0
0
720
71*5
232
610
610
130
3,000
2,580
310
7.20
180
310
15
12
10
0.31
30
197
0.17
350
5.5
22
6.8
1*70
3
31*0
0
336
560
220
5UO
1*20
160
2,560
2,1*80
300
7.25
170
210
15
0
10
0.21*
132
15*
0.13
350
5-5
9
7,5
1*70
3
350
0
222
560
130
610
350
110
2,1*80
2,1*00
230
7.15
160
no
25
0
0
0.23
105
105
0.12
3>*0
U
15
7.5
1*80
5
350
0
130
-------
Table 12 (continued). cOSCBmTIOH OF ECTRACBD MMHOAIfl in USACHATi OBWIWD FROM 7ILL 3
Tine Since Leachate
Production Began, dayi
23!* 255 282 325
350
365 39"f
453 477 506 536 575 613 649 677 712 7*7
-t-
COD, mg/1
BOD,, »g/l
5
TOC, mg/1
T3S, mg/1
VSS, mg/1
B, mg/1
Total Alkalinity, «g/l a> CaCO,
Total Acidity, »g/l « <*C03
*
Total Hardneia, ag/1 ai CaCO^
Acetic Acid, ag/1
Fropionic Acd, mg/1
Butyric Acid, mg/1
Valeric Acid, ng/1
Fborphate, ng/1 ai PO^
Organic nitrogen, ng/1 a» IfO
Ammonia nitrogen, ng/1 »> H
Nitrate Nitrogen, mg/1 •• *°3
Chloride, mg/1
Calcium, ng/1
Magneiium, ng/1
Manganese, ng/1
Sodium, mg/1
Iron, ng/1
Potassium, mg/1
Zinc, mg/1
Total Volatile Acid, ng/1
as Acetic Acid
1*90
125
570
330
90
2,140
2,510
210
7-3
160
120
30
5
0
0.37
91
56
0.13
360
12
Ik
3-5
1*90
5
310
0
147
1*03
1*1*
275
280
120
1,1*60
,5*
205
7.05
i4o
100
20
20
0
0.21
5
49
0.14
340
12
15
3-5
500
7
310
0
130
376
62
250
310
ll*0
1,170
2,510
160
7.15
140
85
60
0
0
0.17
5
3
6k
240
9
14
4.5
470
7
340
0
134
350
66
3VT
260
150
1,200
3.7UO
11*0
7.10
120
80
60
10
0
0.06
7
1
61*
180
8
ll»
4.5
1«9O
12
340
0
135
31*0
85
325
310
120
1,100
2,920
160
7»03
110
78
1*0
0
0
0.09
15
25
9.6
130
13
15
U.O
500
12
3>*0
0
110
290
90
1*50
3UO
120
1,150
2,76o
150
7.03
110
100
1*0
2
0
O.ll
15
1*0
12
110
12
12
2.5
290
8
31*0
0
130
270
88
1*70
1*10
120
1,150
2,81*0
170
7.00
110
75
1*0
0
0
o.iu
35
65
12
130
12
12
2.5
290
8
31*0
0
100
750
61
1*00
U5
55
2,1*00
90
7.2
1*03
...
—
...
—
0.9
ll*
13
.11*
—
100
28
...
190
...
205
O.I*
0
345
13
200
1*3
1*1
2,060
21*0
7.0
"»33
1*0
0
0
0
1.0
13
13
.10
206
112
26
0.8
370
25
212
0-1*
1*0
3»*5
29
200
1,070
168
7.1
377
...
...
—
—
0.1*
15
3
.12
226
100
2U
0.6
1*50
15
200
04
—
1*18
1*0
238
ll*8
39
94l
IBS
6.7
311*
30
0
0
0
1.0
17
3
.15
—
75
21*
0.5
1*10
15
200
0-3
30
3UO
29
22O
33
10
1,086
131
7.4
31*0
—
—
—
...
0.9
13
5
.10
238
90
22
0.5
1*20
10
200
0-3
—
321
23
260
90
...
1,068
56
7.1*
272
20
...
2.0
13
U
.10
270
75
20
0.2
250
13
200
0-3
20
265
33
180
27
27
779
28
7.50
177
111
12
I*
0
1.2
8.0
2.0
0.23
100
5O.O
12.0
0.25
266.0
1.0
ll*l*.0
0.16
12U
237
26
160
11*
D*
905
50
7.30
212
81*
12
1*
0
0.8
8.0
0.0
0.16
135
60.0
ll*.2
0.30
266.0
1.5
11*5.0
0.12
97
211*
26
200
25
25
868
1*0
7.75
155
81*
8
U
0
O.I*
7.0
1.0
0.20
125
30.0
17.5
0.35
297.0
3.0
160.0
0:10
93
208
29
338
23
23
905
80
7.30
128
198
97
U
0
O.I*
7.3
0.7
0.15
120
25.0
15.0
0.60
231*. o
1.5
202.0
0.1*0
280
251
"*5
760
21*
20
905
60
7.70
2¥t
258
233
1*9
0
0.5
6.5
1.5
0.07
J20
70.0
13-7
o.Uo
156.0
5.0
11*0.0
0.60
1*80
-------
Table 13. COHCENTRATIOH OF EXTRACTED MATERIAIfi IB IEACHATE OBTAISED FROM FILL k
Time Since Leacbate
Production Began, days
24
31
38
45
52
68
73
80 87
114
156 169 183 206 221
COD, mg/1
BOD,, mg/1
TOO, mg/1
TSS, mg/1
VSS, mg/1
TS, mg/1
Total Alkalinity, mg/1 as CaCO
Total Acidity, mg/1 as CaCO
PH
Total Hardness, mg/1 as CaCO
Acetic Acid, mg/1
Propionic Acid, mg/1
Butyric Acid, mg/1
Valeric Acid, mg/1
Phosphate, mg/1 as POi
Organic Nitrogen, mg/1 as N
Ammonia Nitrogen, mg/1 as N
Nitrate Nitrogen, mg/1 as N05
Chloride, mg/1
Calcium, mg/1
Magnesium, mg/1
Manganese , mg/1
Sodium, mg/1
Iron, mg/1
Potassium, mg/1
T.inc, mg/1
Total Volatile Acid, mg/1 as
as Acetic Acid
460
195
332
—
—
—
93
30
6 78
—
44
Ik
13
13
0.2?
—
...
—
---
—
—
—
—
—
—
—
72
5,200
3,350
2,030
146
100
3,154
964
920
5 »»5
563
1,000
1,020
350
88
—
92
172
—
—
153
17
19
118
U2
—
—
2,120.
7,200
5,6OO
2,720
210
72
4,983
1 ,735
?,010
5 35
872
1,875
1,800
800
295
1.1(7
45
270
3 1
186
2l»6
31
19
29>t
53
...
—
4,055
9,250
7,900
2,860
355
111
8,097
3,21(0
690
6 58
969
2,150
2,025
850
375
0 27
4
318
2 7
2l»3
290
34
19
1,210
50
535
1-3
4,593
11,750
9,200
3,655
1(1(1
11(6
9,699
3,290
520
6 58
1,206
2,300
2,160
1,075
U75
0 50
30
320
k 0
257
335
1(1
19
1,1(10
91
595
l.o
5,060
11,200
8,500
3,820
558
205
10,1(78
3,565
590
6 05
1,2U9
2,910
2,550
1,275
610
0 1(5
26
324
3 3
—
366
1(3
19
1,880
68
710
1.3
6,200
11,000
8,000
3,1(1(0
361(
85
11,860
3,765
1(20
6 lo
1,293
2,950
2,65o
1,1(25
725
o 25
92
335
s z
286
382
1*3
10
1,600
80
550
5.0
6,U90
15,000
7,6oo
4,000
8ll(
270
11,006
3,1(00
1,020
5 89
1,639
3,11(0
2,750
1,500
855
0 3k
67
339
3 1
250
kko
1(7
19
1,100
174
530
k.3
6,880
15,1(00
10,300
l(,l(30
768
280
ll,3l(6
1(,320
1,370
5 88
1,168
3,950
3,380
1,770
1,220
0 31
, 114
376
3 3
238
30',
1(9
13
1,590
100
570
7.5
8,620
17,1(00
12,100
4,330
1,225
393
12,169
4,560
860
6 2k
1,335
4,000
3,750
2,000
1,970
0 22
67
koo
2 7
272
325
52
12
i.Uoo
160
600
20
9,560
18,000
11,200
1(,800
1,101
31(2
12,31k
4,700
900
6 19
1,1(28
2,1(00
2,270
1,1*95
1,790
...
75
koo
3 1
276
340
53
13
1,600
188
590
22
6,310
15,800
12,300
4,500
690
192
13,458
4,540
580
6 59
1,455
2,530
2,210
1,475
1,820
0 20
83
4oo
0 4
286
365
52
12
1,600
115
605
12
6,390
17,600
14,650
4,925
463
151
12,770
4,9OO
800
6 32
1,167
2,200
2,320
1,350
1,670
0 28
75
400
0 6
268
300
53
11
2,300
100
563
17
5,960
17,710
14,500
5,700
750
110
12,000
4,450
890
645
750
2,260
5,780
1,000
1,420
o 17
48
448
0 20
280
310
55
13
l,6oo
110
550
17
8,480
16,650
14,000
5,655
780
60
10,500
4,400
1,010
6 60
540
2,310
5,350
720
1,30O
o 30
48
408
0 18
250
350
24
11
l,4oo
120
550
15
7,920
16.5401
13,000
5,685
750
70
8,500
4,560
11,090
6 70
260
2,420
5,100
600
1,200
0 21
32
376
0 15
310
280
12
4 5
1,200
150
510
10
7,686
14,000
12,300
5,080
820
100
8,500
4,280
1,070
6 65
210
2,100
3,620
510
640
023
96
360
0 24
320
155
12
3 1
1,250
110
515
0.95
5,760
13,2OO
11,500
5,210
840
70
7,800
4,84o
1,240
6 65
200
2,200
2,420
370
540
0 17
254
210
o 25
290
125
31
2 7
1,150
75
500
OJ5
4,74o
14,500
12,300
4,940
1,180
85
7,000
4,870
1,340
6 75
190
2,140
1,540
310
400
0 12
157
96
0 20
300
70
31
0 4
1,125
75
495
0
3,835
13,000
12,500
4,220
720
65
6,440
4,880
1,390
7.UO
180
1,700
890
215
210
0 12
133
67
0 19
310
20
34
0
1,200
40
480
0
2,690
-------
Table 13 (continued). CONCENTFATIOH OF EXTRACTED MATERIA1S IN IEACHATE OBTAINED FROM FIU, I*
Time Since Leachate
Production Began, days
255 282 325 350 365
"*23 U53 U70 506 51*7
575
58U 621 656 691 726 7U7
COD, mg/1
BOD., mg/1
TOC, mg/1
TSS, mg/1
VS8, mg/1
TS, mg/1
Total Alkalinity, mg/1 as CaCO,
Total Acidity, mg/1 as CaCO,
pH
Total Hardness, mg/1 as CaCO,
Acetic Acid, mg/1
Propionlc Acid, mg/1
Butyric Acid, mg/1
Valeric Acid, mg/1
Phosphate, mg/1 as POr
Organic Nitrogen, mg/1 as N
Ammonia Nitrogen, mg/1 as N
Nitrate Nitrogen, mg/1 as No"
Chloride, og/l
Calcium, mg/1
Magnesium, rng/1
Manganese, mg/1
Sodium, mg/1
Iron, mg/1
Potassium, mg/1
Zinc, mg/1
Total Volatile Acid, mg/1 as
Acetic Acid
11,800
9,1; 50
3,660
760
70
5frlO
• WJ.U
5, >WO
1,310
7.UO
180
2,000
680
210
200
0.12
131
67
0.19
320
15
3U
0
1,200
20
310
0
2,812
7,100
5,500
3,300
1,030
1*50
1| OQQ
5,800
800
7.1*5
160
1,800
51*0
110
80
0.17
70
126
0.23
3>*0
11*
36
0
1,250
21
310
0
2,360
5,500
5,050
2,600
720
60
•j jiii/i
jjtHU
6,010
810
7.50
160
1,600
5UO
80
0
O.It
30
101*
0.05
170
17
36
0
1,350
118
310
0
2,093
2,1*80
2,300
1,11*0
900
250
2li OC
> **•-}?
6,180
310
7.1*0
11*0
1,1*00
61*0
25
5
0.28
26
101
0.05
160
12
20
0
1,000
15
300
0
l,9l*0
1,1*50
1,100
930
850
250
271O
i f J.U
5,81*0
260
7.20
11*0
51*0
110
10
0
0.31
16
76
0.15
130
12
18
0
890
15
300
0
6UO
950
660
980
800
170
2 210
5,760
21*0
7.20
lUO
280
75
5
0
0.28
50
62
0.11
130
15
15
0
81*0
22
300
0
350
780
250
960
650
ll*0
1 1*60
5,1*20
21*0
7.10
ll*0
90
1*0
1
0
0.2U
U4
16
0.11
130
15
15
0
81*0
22
300
0
125
1,000
310
390
145
70
3,600
—
7.6
120
25
5
0
1.3
10
39
0.1
238
75
26
...
800
...
225
0.9
ll*l*
1*00
35
199
70
3"*
3,280
250
7.2
110
15
2
0
1.3
8
36
0.08
...
75
21*
0.7
850
23
220
1.0
126
330
70
179
1*8
12
1,795
168
7.2
...
—
...
...
1.1
11
2U
0,17
310
67
22
0.7
8OO
20
220
0.9
1*20
75
179
1*6
26
1,593
228
6.9
80
5
0
0
0.6
8
26
0.1
190
70
16
0.7
750
17
205
0.8
81*
300
36
ii*o
1*0
9
1,665
94
7.3
...
...
—
—
1.0
6
26
0.1
...
70
18
0.7
830
21
200
1.0
280
53
115
86
38
1,61*7
131
7.1
50
1
0
0
0.9
9
23
0.1
220
70
16
0.7
750
10
200
1.8
51
3"*7
1*3
160
52
50
1,555
ll*0
7.05
112
139
16
8
0
0.6
13.0
6.0
o.oi*
250
25.0
8.2
0.75
625.0
6.0
162.5
0.85
157
198
1*6
105
102
1*2
1,1*50
65
7.11
130
111
16
U
0
0.6
10.5
U.5
0.05
115
35.0
7.0
1.1*5
1*7.0
5.0
132.5
0.1*0
127
1*8
38
90
1*6
25
1,320
80
7.10
ll*2
96
8
i*
0
1.1
5.5
It. 5
0.05
100
37.5
6.8
1.50
828.0
7.5
130.0
0.58
107
175
38
250
60
39
1,375
150
7.05
153
300
11*6
23
0
0.5
10.2
2.8
o.iU
130
31.3
10.0
0.80
1*37.0
12.5
11*7.5
1.33
1*33
196
38
355
5U
39
1,375
150
7.10
172
513
201*
61
0
0.1*
10.9
3-1
0.07
130
32.5
13-7
1.1*0
562.0
13.0
11*5.0
0.20
720
210
31
1,000
M*
21*
1,375
180
7.00
122
U12
271
0
0
0.5
12.5
lt.5
0.06
130
20.0
10.0
0.70
1*22.0
11.5
11*0.0
0.60
631
-------
D—G
O O
CONTROL
LEACHATE RECYCLE
LEACHATE RECYCLE AND pH ADJUSTMENT
LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
60 120 180 240 300 360 420 480
TIME SINCE LEACHATE PRODUCTION BEGAN,days
FIGURE 5 BIOCHEMICAL OXYGEN DEMAND OF LEACHATE
780 840 900 ~960 1020 1080 1140
-------
CD
CONTROL
LEACHATE RECYCLE
0—n LEACHATE RECYCLE AND pH ADJUSTMENT
o—o LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
60 120 180 240 300 360 420 480 540 600 660 720 780 84O 900 960 1020 1080 1140
TIME SINCE LEACHATE PRODUCTION BEGAN,days
FIGURE 6 CHEMICAL OXYGEN DEMAND OF LEACHATE
-------
6000
5000
CONTROL
LEACHATE RECYCLE
LEACHATE RECYCLE AND pH ADJUSTMENT
o—O LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
4OOO-
O)
E
O
CO
oc
o
3000 •
i
o
200
1000
60 120 180 240 300 360 420 480 540 600 660 720 780 840 900 960 1020 1080 1140
TIME SINCE LEACHATE PRODUCTION BEGAN, days
FIGURE 7 TOTAL ORGANIC CARBON CONCENTRATION OF LEACHATE
-------
CONTROL
•—• LEACHATE RECYCLE
D—D LEACHATE RECYCLE AND pH ADJUSTMENT
O—O LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
ui
o
60 120 180 240 UOCT360 *20~480 *B40 ~WXT 660 720* ~780 840 900 "960 T020 1080 1140
TIME SINCE LEACHATE PRODUCTION BEGAN , days
FIGURE 8 VALERIC ACID CONCENTRATION OF LEACHATE
-------
Hi CONTROL
-• LEACHATE RECYCLE
-a LEACHATE RECYCLE AND pH ADJUSTMENT
-o LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
60 120 240 300 360 420 480 540 600 720 840 960
TIME SINCE LEACHATE PRODUCTION BEGAN, days
1080
FIGURE 9 BUTYRIC ACID CONCENTRATION OF LEACHATE
-------
6000
vn
ro
5000
CONTROL
•—• LEACHATE RECYCLE
°—o LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
D—D LEACHATE RECYCLE AND pH ADJUSTMENT
60 120 180 240 300 360 420
TIME SINCE LEACHATE PRODUCTION BEGAN,days
840 900 960*1020 1080 1140
FIGURE 10 PROPIONIC ACID CONCENTRATION OF LEACHATE
-------
6000r
V/l
5000
CONTROL
LEACHATE RECYCLE
LEACHATE RECYCLE AND pH ADJUSTMENT
0—0 LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
4000
3000-
01
E
O
UJ
o
2000
1000.
60 120 180 240 300 360 420 480 540 6OO 660 720 780 840 9OO 960 1020 1080 1140
TIME SINCE LEACHATE PRODUCTION BEGAN,days
FIGURE 11 ACETIC ACID CONCENTRATION OF LEACHATE
-------
CONTROL
LEACHATE RECYCLE
LEACHATE RECYCLE AND pH ADJUSTMENT
LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
60 120 180 240 300 360 420 480 540 600 720 84O
TIME SINCE LEACHATE PRODUCTION BEGAN, days
960
1080
FIGURE 12 pH AND TOTAL VOLATILE ACID CONCENTRATION
OF LEACHATE
-------
3600
CONTROL
LEACHATE RECYCLE
D—D LEACHATE RECYCLE AND pH ADJUSTMENT
O—o LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
60 120 180 240 300 360 420 480 540 600 660 720 780 840 900 960 1020 1080 1140
TIME SINCE LEACHATE PRODUCTION BEGAN,days
FIGURE 13 ACIDITY OF LEACHATE
-------
6000 r
V/l
CONTROL
LEACHATE RECYCLE
D—D LEACHATE RECYCLE AND pH ADJUSTMENT
0—0 LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
60 120 180 240 300 360 420 480 540 600 660 720 780 840 900 960 1020 1080 TI40
TIME SINCE LEACHATE PRODUCTION BEGAN
FIGURE 14 ALKALINITY OF LEACHATE
-------
300
Z
01
Z
o
400 •
300 •
200
100
CONTROL
LEACHATE RECYCLE
LEACHATE RECYCLE AND pH ADJUSTMENT
LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
60
120 180 240 300 360
TIME SINCE LEACHATE PRODUCTION BEGAN, days
080 1140
FIGURE 15 CONCENTRATIONS OF ORGANIC AND AMMONIA NITROGEN
IN LEACHATE
-------
V/l
00
CONTROL
LEACHATE RECYCLE
D—o LEACHATE RECYCLE AND pH ADJUSTMENT
LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
0 60 120 180 240 300 360 420 480 540 600 660 720 780 840 900 960 1020 1080 1140
TIME SINCE LEACHATE PRODUCTION BEGAN, days
FIGURE 16 PHOSPHATE AND CHLORIDE CONCENTRATION OF LEACHATE
-------
•—• CONTROL
•—• LEACHATE RECYCLE
0—a LEACHATE RECYCLE AND pH ADJUSTMENT
LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
60 120 180 240 300 360 420 480 540 600 660 720 780 840 900 960 1020 1080 1140
TIME SINCE LEACHATE PRODUCTION BEGAN,days
FIGURE 17 IRON AND SODIUM CONCENTRATIONS OF LEACHATE
-------
CT\
O
111
I
1200
CONTROL
LEACHATE RECYCLE
LEACHATE RECYCLE AND pH ADJUSTMENT
LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
60
180 240 300 360 420 480 540 600 660 720 780 840 900 960 1020 1080 1140
TIME SINCE LEACHATE PRODUCTION BEGAN, days
FIGURE 18 MANGANESE, MAGNESIUM AND CALCIUM CONCENTRATIONS
OF LEACHATE
-------
6000
CONTROL
•—• LEACHATE RECYCLE
0—0 LEACHATE RECYCLE AND pH ADJUSTMENT
o—o LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
60 120 180 240 300 360 420 480 540 600 660 720 780 840 900 960 1020 1080 1140
TIME SINCE LEACHATE PRODUCTION BEGAN, days
FIGURE 19 TOTAL HARDNESS OF LEACHATE
-------
800
ON
ro
CONTROL
LEACHATE RECYCLE
LEACHATE RECYCLE AND pH
ADJUSTMENT
LEACHATE RECYCLE, pH ADJUSTMENT AND
INITIAL SLUDGE ADDITION
0 60 120 180 240 300 360 420 480 540
TIME SINCE LEACHATE PRODUCTION BEGAN, days
660 720 780 840 900 960 1020 1080 1140
FIGURE 20 SOLIDS CONCENTRATION OF LEACHATE
-------
ON
OO
X
a
8
7
6
5
2700
(A
S 2400
o>
8 2100
* 1800
§ 1500
£ 1200
900
uj 600
3 300
I
•D-
0 RECIRCULATING FILL WITH pH CONTROL, FILL 3
O RECIRCULATING FILL WITH pH CONTROL AND
SLUDGE SEED, FILL 4
r
NO ADDITIONAL NEUTRALIZATION PERFORMED
40 80 120 160 200 240 280
TIME SINCE LEACHATE PRODUCTION BEGAN, days
320
380
FIGURE 21 ADDITION OF NEUTRALIZING AGENT, SODIUM HYDROXIDE,
DURING PHASE II
-------
Leachate Neutralization during Phase II
Daily and cumulative quantities of sodium hydroxide used for temporary
neutralization during Phase II are graphically represented in Figure 21
together with the corresponding daily pH readings. At the end of 95 days,
the sodium hydroxide added to the leachate from Fill 3 began to level off
as the demand diminished and until a value of 1020 grams of sodium hydroxide
had been added to maintain a pH of 6.9. On the other hand, the leachate
from Fill h continued to require more neutralization until 2080 grams of
sodium hydroxide had been added after 120 days of leachate production and an
adjusted pH of 6.5.
Addition of raw primary sludge to Fill k caused a neutralizing require-
ment of nearly twice that of Fill 3. Even with this two-fold increase in
neutralization requirement, the leachate pH of Fill k was generally below
that of Fill 3 and only sporadically increased above pH 6.5. Conversely,
the leachate pH of Fill 3 increased above 6.5 several times and after ?8 days
showed a general upward trend from pH 6.55 to pH 7.03 at 96 days.
GAS ANALYSIS
Gas collection and analysis were not included during Phase I but data
showing the relative amounts of carbon dioxide and methane in the gas
collected during Phase II are displayed in Table Ik. Since it was difficult
to obtain a sample from the test columns without introducing air, the per-
centages of carbon dioxide and methane were determined by analysis and then
adjusted to reflect relative composition if the gas produced contained only
these two constituents. The gas from Fill k generally exhibited a more
consistent methane content than the analyses indicated for Fill 3. However,
the sampling technique used during the study precluded determination of total
quantities of gas produced and therefore only allowed for a qualitative
characterization throughout the test period.
ANALYSIS OF RAW PRIMARY SLUDGE USED DURING PHASE II
Analysis on the raw primary sludge initially added to Fill k included;
total organic carbon, total suspended solids, volatile suspended solids,
total solids, hardness, volatile acids, ammonia and organic nitrogen, nitrate,
chloride, phosphate, calcium, magnesium, manganese, sodium, iron, potassium
and zinc. The tabulation of the data is presented in Table 15- These tests
were used to ascertain the nutrient, organic and inorganic quality as well as
possible inhibitory effects of the sludge addition to Fill k.
-------
Table l4. COMPOSITION OF GAS PRODUCED DURING PHASE II
Week of .
test
period
7
12
32
44
58
67
76
84
99
108
Fill 3 Fill 4
Composition, % by volume
COg CH^
100.0
50.3
50.0
23.7
28.6
34.1
41.5
28.5
0.0
49.7
50.0
76.3 .
71.4
65.9
58.5
71.5
Composition, % by volume
53.0
41.5
21.4
18.2
50.0
42.3
35.1
4o.o
30.7
41.4
47.0
58.5
78.6
81.8
50.0
57.7
64.9
60.0
69.3
58.6
65
-------
Table 15. ANALYSIS OF RAW PRIMARY SLUDGE ADDED TO FILL k IN PHASE II
Sludge
constituent
Concentration
Sludge
constituent
Concentration
Total organic carbon, mg/1
Total suspended solids, mg/1
Volatile suspended solids, mg/1
Total solids, mg/1
Total hardness, mg/1 as CaCO
Volatile acids:
Acetic acid, mg/1
Propionic acid, mg/1
Butyric acid, mg/1
Valeric acid, mg/1
Ammonia nitrogen, mg/1 as K
3,300
57,850
33,^00
63,100
582
6,830
815
600
290
361
Organic nitrogen, mg/1 as N
Nitrate, mg/1 as N0_
Chlorides, mg/1
Phosphorous, mg/1 as POi
Calcium, mg/1
Magnesium, mg/1
Mangane se, mg/1
Sodium, mg/1
Iron, mg/1
Potassium, mg/1
Zinc, mg/1
lif.O
0.91
27.6
7.0
138
25
0.0
50
75
132
0.05
-------
SECTION VI
DISCUSSION
The sanitary landfill method of solid waste disposal depends largely
upon anaerobic biological activity to stabilize the decomposable fractions
of refuse. The anaerobic process is considered to proceed through two
identifiable phases with conversion of the larger organic molecules into
intermediates including mainly the volatile short-chained organic acids
(acid fermentation), and subsequent conversion of the short-chained acids
to carbon dioxide and methane (methane formation).
The methane formation phase is generally considered the rate control-
ling step in the anaerobic process since it proceeds at a much slower rate
and is more sensitive to environmental stresses than acid fermentation.
Methane forming organisms generally require strict anaerobic conditions, a
near neutral pH and absence of inhibitory substances. If acid production
exceeds the rate of methane formation to an extent greater than the capacity
of the system to buffer the acids produced, the PH will fall below the level
at which the methane producing organisms can survive and the methane forming
phase of the process will cease to function efficiently. In an efficiently
operating anaerobic system, however, volatile acids concentration wilj. _
initially rise to a peak value and then decrease with concurrent changes in
the concentration of the individual volatile acids. The pH of the_system
may decrease during the increase in volatile acids and will then rise steadily
while the volatile acids diminish as a consequence of conversion to methane
and carbon dioxide.
The effect of leachate recycle on the stabilization processes occurring
within a sanitary landfill was examined for 1063 days during Phase I and for
7U7 days during Phase II of the experimental studies. Whereas the landfill
environment was not adjusted except by leachate recirculation during Phase I,
more favorable conditions for anaerobic digestion were induced during Phase II
by maintaining the PH in both fills near neutral and also by adding primary
sewage sludge to Fill h. The significance of trends observed in leachate
quality and landfill stabilization are discussed as they relate to ^ndfill
practices and possible remedy for potential environmental pollution problems.
CHANGES IN LEACHATE QUALITY WITH RECYCLE
The data obtained during the experimental studies have demonstrated that
leachate recycle markedly reduced the concentrations of readily decomposable
pollutants emitted in the leachate from a simulated landfill containing
mSriafs cn^acteristic of residential refuse. In addition to the comparison
67
-------
of simple leachate recycle, the relative benefits of pH control on waste
stabilization were ascertained together with the effects of initial raw
sludge additions. In general, leachate recycle with initial neutralization
promoted a more rapid development of methane formers with a concomitant
increase in rate of stabilization and removal of pollutant concentrations
from the leachate. Seeding with raw primary sludge further accelerated the
biological stabilization processes initially with a more rapid and larger
production of volatile acids and organic pollutants in the leachate but also
with an eventual reduction in stabilization time for the readily decomposed
organic materials in the leachate when compared to the fill without recycle.
Volatile Acids and pH
When dealing with an anaerobic system such as the environment within a
sanitary landfill, the concentration of volatile acids and pH can be most
important indicator parameters. The low molecular weight fatty acids (acetic,
propionic, butyric, and valeric) are very diagnostic of the stage and degree
of stability of the anaerobic process. Figures 8 through 11 reflect the
behavior of the individual volatile acids during both Phase I and Phase II
of the study and Figure 12 demonstrates their impact on pH when external
neutralization was not used.
Phase I
During Phase I there was an early rise in volatile acid concentrations
in both Fill 1 and Fill 2 with acetic acid being the most abundant acid. A
reduction in acetic and propionic acids was generally preceded by reductions
in butyric and valeric acids in Fill 2. Decrease in volatile acids was
accompanied by an increase in pH from 5.3 to 6.2 at about l6o days. The
reduction in volatile acids in Fill 1 began at about 280 days after which time
the acids decreased steadily but without a corresponding increase in pH.
The individual volatile acid concentrations in Fill 2 had decreased
dramatically after about 280 days. The low volatile acids concentrations
at this time resulted in an increase in pH to 7.1. The total volatile
acids in Fill 1 decreased gradually during the 1063-day study period from
a maximum of 9300 mg/1 at 228 days to 2135 mg/1 at the end of the test
period; Fill 2 concentrations decreased from a maximum of 5818 mg/1 at 96
days to a minimum of 60 mg/1 and a final concentration of 733 mg/1 at the
end of the test period. This change was considered indicative of the removal
of readily available organic pollutants from the refuse and leachate with
an eventual attack on more resistant materials in the refuse and the appear-
ance in the leachate of their volatile acid conversion products. Additional
monitoring has indicated a trend toward decrease in these volatile acid
residuals. A similar trend has not yet been observed for the control fill
although there appeared to be a less dramatic decrease in volatile acids
concentration followed by an increase which may also have been somewhat
indicative of the readily decomposable—resistant materials conversion
pattern.
68
-------
Phase II
After an initial peak at about hO-80 days, the individual volatile acids
concentrations in Fill 3 decreased rapidly to consistently low values with
the higher homologues generally preceding the shorter chain acids in reaching
stability in concentration. When the pH in Fill 3 had been adjusted to 6.8l
at 52 days, addition of NaOH for pH control was terminated. Thereafter, the
total volatile acids concentration decreased from 5105 mg/1 at ^-5 days to 130
mg/1 at 221 days at a more rapid pace and in less time than indicated pre-
viously for Fill 2. Thereafter, total volatile acids concentration varied
from negligible to 480 mg/1 for the remainder of the test period. The pH
control provided by external neutralization apparently created a more favor-
able environment for rapid conversion of the volatile acids to methane and
carbon dioxide with an increased rate of stabilization of the organic compo-
nents of the refuse over that observed for Fill 2.
For Fill k, the total volatile acids concentration peaked by 120 days
after which time the acids steadily decreased to low levels similar to the
other fills with leachate recycle. The maximum total volatile acid concen-
tration in Fill k was 9560 mg/1 or higher than experienced in Fill 3 thereby
indicating that the addition of raw primary sewage sludge accelerated acid
fermentation and probably also added to the reservoir of readily available
organic material in the fill. As a consequence, pH adjustment was required
for about l60 days to achieve a pH of 6.65. Accordingly, about 2520 grams
of sodium hydroxide were added to Fill 4 as compared to 1020 grams to Fill 3-
As observed for Fills 1 and 2, the concentrations of butyric and valeric
acids in Fill 3 decreased to low levels (at about 80 days) again prior to
propionic (at about l60 days) and acetic (at about 300 days) thereby suggest-
ing a sequential pattern of conversion. Similarly, it took over 300 days for
butyric and valeric acids to decrease to their low levels in Fill k followed
somewhat by propionic and acetic acids. In addition, reductions in volatile
acids to a minimum concentration followed by a gradual increase suggested con-
version of readily available organic with subsequent attack on the more resi-
stant materials in the refuse. Furthermore, the higher concentration of pro-
pionic acid in Fill ^ was characteristic of an anaerobic system which received
an unusual loading accountable to the raw sludge addition.
Comparison of the results for the four fills indicated that leachate
recycle was beneficial to the removal and conversion of readily available
organics in the refuse through conversion to volatile acids in the leachate
and then to methane and carbon dioxide. In the absence of recycle, the
leachate continued to contain relatively high volatile acids concentrations
even after 1063 days of study.
Organic Pollutant Parameters (BOD, COD and TOG)
As could be expected, BOD, COD and TOG followed the same removal trend
as the volatile acids. In each fill, the peak concentrations occurred at
approximately the same time and decreased correspondingly.
69
-------
Phase I
The concentration of BOD, COD and TOC for Fill 2 decreased to relatively
low constant values in about 300 days whereas in Fill 1, after reaching a
maximum, these parameters decreased only gradually. The BOD, COD and TOC
maxima were 13,^00 mg/1, 18,100 mg/1 and 5000 mg/1 versus 10,100 mg/1,
10,500 mg/1 and 2798 mg/1 for Fills 1 and 2, respectively. Residual con-
centrations again remained to be considered in terms of ultimate discharge
requirements.
Phase II
Leachate recycle with pH adjustment again resulted in a more rapid
decrease in pollutional characteristics and as measured by BOD, COD and TOC,
reached consistently low levels at about 130 and kOO days for Fills 3 and
k, respectively. The delay in neutralization for pH control after raw sludge
seeding for about two weeks apparently caused a temporary promotion of acid
conditions in Fill 4 which delayed the desired production of methane from
the volatile acids. However, once pK control had become effective, a dramatic
reduction in all pollutional parameters occurred. As with the Phase I fills,
residual concentrations remained at the end of the test period.
Acidity and Alkalinity
During the experimental investigations, the predominant source of acidity
was the volatile acids so that acidity increased or decreased as the volatile
acids increased or decreased unless otherwise moderated by addition of NaOH
for neutralization. likewise, the alkalinity was reflected by the association
of cations and anions present in the system which under normal operations would
include the carbon dioxide-bicarbonate-carbonate buffer system at neutral pH
and the volatile acids buffer system at low pH. Therefore, direct relation-
ships could be anticipated between the acid-base constituents present, i.e.,
volatile acids, ammonium, calcium (and magnesium), and sodium particularly
when added for pH control.
Phase I
The acidity of the leachate from Fill 2 decreased dramatically at about
200 days and corresponded to decreases in volatile acids, BOD, COD and TOC.
At the end of the study period, the acidity of Fill 1 remained high at 1290
mg/1 while that of Fill 2 was only 110 mg/1.
The alkalinity in the leachate from Fill 1 remained relatively constant
during a considerable portion of the study period at about 2200 mg/1. However,
it decreased consistently after about 700 days to a final concentration of
760 mg/1. The alkalinity in the leachate from Fill 2 also decreased gradually
with time as a consequence of dilution and the impact of other reactions within
the fill. The alkalinity in the leachate from both Fills 1 and 2 generally
reflected the magnitude of the buffer capacity established at either acid or
neutral pH.
70
-------
Phase II
The acidity in the leachate of Fills 3 and h changed as expected with
changes in organic pollutant concentrations in the leachate. The impact of
the initial raw sludge addition on acid production was reflected in the
increase in acidity for Fill k. The initial acidity in leachate from Fills
3 and k was generally less than that of Fills 1 and 2 due to the addition
of NaOH for neutralization after two weeks.
The alkalinity in the leachate from Fills 3 and k indicated the influence
of base additions for pH control and thus were of greater magnitude than for
Fills 1 and 2. Some fluctuation was noted as is also illustrated in similar
changes in sodium concentration (Figure 17). The concentration of sodium
remained less than the concentration of this cation reported as toxic to the
anaerobic stabilization process and therefore toxic effects were not considered
as an issue during data analysis.
Nitrogen and Phosphate
Phase I
The concentrations of organic and ammonia nitrogen were lower in the
leachate from Fill 2 than in the leachate from Fill 1. The organic nitrogen
decrease tended to precede the decrease in ammonia nitrogen as a consequence
of sequential conversion, however, the concentrations were probably also
changed as a consequence of biological utilization and/or dilution. Whereas
the organic and ammonia nitrogen concentrations in the leachate from Fill 1
were l4 mg/1 and 2 mg/1 respectively at the end of 1063 days, measured con-
centrations for Fill 2 decreased to zero on several occasions and were prac-
tically nil at the end of the test period.
The initial phosphate concentrations were relatively high in the leachate
from both fills as soluble phosphate was leached by the initial addition of
water. The ensuing concentrations reflected higher values for Fill 1 than
Fill 2 probably as a consequence of greater biological utilization and/or
dilution in the latter.
Phase II
After initial high concentrations of both organic and ammonia nitrogen?
a gradual decrease occurred in the concentrations in Fill 3 whereas, in Fill
k they did not decrease until about 200 days had elapsed. The initial raw
sludge addition to Fill h again had its impact on the nitrogen content with
greater initial concentrations in the leachate from Fill U than in that from
Fill 3. However, with time these concentrations decreased to values of
similar magnitude.
Both Fills 3 and k seemed to be utilizing the phosphate present and more
rapidly than indicated for Fills 1 and 2. This again supported the likelihood
that Fills 1 and 2 initially were less biologically active with respect to
complete conversion of readily available organic materials than Fills 3 and
71
-------
k because of the absence of pH adjustment and/or sludge seeding.
Metals and Hardness
Phase I
For the first l6o days, the concentration of iron was similar and in-
creased steadily in both Fill 1 and Fill 2 probably as a consequence of the
emergence of acid conditions (some corrosion of metal fixtures) and a more
reducing condition in the fills. However, after l6o days, the iron concen-
tration in the leachate from Fill 2 decreased sharply as the pH increased
from about 5.2 to 7.2. It was concluded that as the pollutants were removed
from the leachate of Fill 2, the environment became less reducing, permitting
the possible oxidation and precipitation of iron from the leachate. Such a
possibility was evidenced by a brownish color in the recycled leachate from
Fill 2 at that time as compared to the corresponding greenish color of the
leachate from Fill 1. At about ^30 days, the iron concentration was essen-
tially zero in the leachate from Fill 2 whereas the iron concentration in the
leachate from Fill 1 remained high and above UOO mg/1 at the end of the 1063-
day study period. In addition, some iron was removed in the Phase I fills
as a consequence of corrosion of some of the fittings particularly at low pH
when iron would be more soluble.
In the early stages of the study, the manganese concentration was higher
in the leachate from Fill 2 which may also have reflected a more reducing
enrironment than in Fill 1 with the insoluble manganese being reduced to the
soluble manganous form. In fact, the leachate from Fill 1 never reached a
manganese concentration above 20 mg/1 throughout the 1063 days of the study
while a maximum of 93 mg/1 was obtained for Fill 2 at iko days. As with iron,
the concentration of manganese in the leachate from Fill 2 began to decrease
as the pH rose and thereafter reached a relatively low value of 10 mg/1 at
214-9 days. However, unlike iron, manganese is relatively soluble up to pH 9
and thus soluble throughout the pH range established during the study. As a
consequence, it was possible that the decrease in soluble manganese might
have been due to a lessening of the reducing conditions within Fill 2 as
stabilization progressed. At 1063 days, the manganese concentration in the
leachate from Fill 1 was 5.k mg/1 while it was essentially zero at about
500 days in Fill 2.
Sodium concentrations in the leachate from both fills were low throughout
Phase I. Concentrations of 15 mg/1 and l6 mg/1 were recorded for Fills 1
and 2, respectively, at the end of the study period. In contrast, the con-
centrations of calcium and magnesium, although similar for about the first
200 days, became somewhat dissimilar thereafter probably, as a consequence
of operational modes and the influence of rainfall. The relatively intense
rainfall between 200 and 220 days of the study period washed out a considerable
concentration of Ca and Mg which appeared subsequently as a slug in the leach-
ate from Fill 1. This rainfall also subsequently caused some dilution of
concentration in the leachate from Fill 2. In addition, it is possible_that
reductions in concentration might have been due to the opportunity for ion
exchange and the formation of organometallic complexes which would have been
72
-------
more possible in Fill 2 than in Fill 1. This exchange or complexation
being pH-Eh dependent would be difficult to predict because of the dif-
ferences in operation and degrees or state of stabilization at any one
period of analysis.
Phase II
The iron concentration in the leachate varied considerably between
Fills 3 and k after an initial period of ^5 days. However, the concentration
in the leachate from Fill 3 decreased to very low values after 80 days when
the pH increased from 6.2 to 7.05 as a consequence of neutralization and/or
effective biological stabilization. The iron in the leachate from Fill 4 did
not decrease to low values until about 2Uo days had elapsed and when the pH
increased from 6.7 to 7.U. At these times, there was a noticeable change in
leachate color from greenish-brown to light brown. Therefore, it is likely
that with the decrease in volatile acids and increase in pH, a more oxidizing
environment prevailed with a concomitant possibility for conversion of the
ferrous to the ferric form of iron although the leachate was consistently
devoid of dissolved oxygen.
Although manganese has similar chemical characteristics as iron, it
appeared that relatively little soluble manganese was present in the leachate
from either Fill 3 or Fill h during the study period with recorded concentra-
tions less than 25 mg/1. Similarly, the concentrations of magnesium in the
leachate from both fills were low and generally ranged between 12 and 15 mg/1.
Recycle of the leachate tended to maintain relatively constant concentrations
of both manganese and magnesium.
Calcium concentrations in the leachate from Fill 3 were lower than in
that from Fill k during the initial 200 days after which time the concentra-
tions were low and essentially constant. Compared to the analyses from Phase
I, concentrations in the leachate from the Phase II fills decreased much more
rapidly which again may have been a consequence of the neutralization proce-
dures employed and possible ion exchange or complex formation. Neutralization
also increased the sodium level in Fills 3 and U in accordance with the amount
of caustic soda added for pH control (Figure 21). Accordingly, Fill k received
and maintained larger concentrations; the maximum of 2300 mg/1 at about 90
days was not considered sufficient to impart a toxic effect on the biological
processes occurring in the fills.
Screening analyses for copper, zinc, nickel, lead and chromium were also
conducted during each phase of the study. Except for measurable concen-
trations of zinc, these metals appeared only in trace quantities. A concen-
tration of U2.5 mg/1 zinc was detected at 556 days in Fill 1 which decreased
to 18 7 nw/1 at the end of the study period. The zinc concentration in Fill
1+ reached its peak of 22 mg/1 at 73 days and then gradually decreased to zero
at 200 davs It is possible that the behavior and delayed appearance of zinc
was a consequence of its initial precipitation in the fills with sulfides and
later release in the leachate as the environment became less reducing and the
sulfides were oxidized.
73
-------
The total hardness in the leachate from each fill reflected the pattern
of divalent cations present. Of particular significance was the change in
calcium concentration which correspondingly determined the change in hardness
during both phases of the study.
Solids
Phase I
Although it was difficult to attach meaningful interpretation to the
solids data because of the interdependence of the various physical and chemical
processes occuring in the fills at any one time, the total solids concentration
in the leachate from Fill 2 was reduced to 700 mg/1 as compared to 2100 mg/1
for Fill 1 after ?20 days. As supported by the greater reduction in pollu-
tional content, the solids concentration could also be considered indicative
of a greater degree of stabilization with leachate recirculation although
mechanical filtration was also operative as the leachate passed through the
fill.
Phase II
Solids data on the Phase II fills were less conclusive except to reflect
the contribution of caustic soda used for neutralization to the total solids
and a seemingly more rapid decrease with time when compared with Fills 1 and 2.
Again, interpretive analysis was curtailed by the mode of operation and limi-
tations on obtaining truly representative and meaningful samples.
EFFECTS OF pH CONTROL ON LANDFILL STABILIZATION
The more rapid improvement in quality of the leachate from the fills with
leachate recycle with or without pH adjustment emphasized the beneficial effect
of the development of a more active anaerobic biological system in these fills.
This was especially apparent when the leachate analyses from Fill 1 were com-
pared to those from Fills 2 and 3. However, the fill with leachate recycle,
pH control, and the initial addition of primary sludge (Fill 10 was not ini-
tially as effective in improving the quality of leachate due to the apparent
conflict between pH control which would abet efficient anaerobic digestion
and conversion of pollutants, and the additional loading of primary sludge
which would and did create an environment most beneficial to rapid formation
of volatile acids and therefore initially unfavorable to methane forming
bacteria because of detrimental increases in volatile acid concentrations.
Therefore, raw sludge seeding did not initially aid in the total anaerobic
stabilization process, and in fact caused it to be delayed as a consequence
of a time lapse between seeding the fills with raw primary sludge and initia-
ting the neutralization process; a delay of approximately two weeks. However,
once neutralization became effective, similar results were obtained between
the Phase II fills.
-------
Refuse Composition
Except for the analyses performed on the refuse initially added to the
simulated landfills, representative samples of the refuse from the landfill
columns were very difficult to obtain. The sampling ports were too small for
convenient removal of representative materials in quantity necessary to assure
reliability of analysis. The samples from the Phase I fills were taken from
near the surface of the fills and probably were less representative than the
samples from the Phase II fills which were removed from near the center of each
fill.
In spite of these difficulties, the analyses presented in Table 5 gener-
ally support the contention that anaerobic biological stabilization of the
organic fraction of the refuse proceeded further in the fills with leachate
recycle than in the control fill of Phase I. The relatively high carbon con-
tent in the refuse samples at the end of the test periods probably reflected
the remaining paper fraction with less carbon generally detected in the refuse
of the fills with leachate recycle where greater stabilization had occurred.
Reductions in volatile solids with time, particularly in the fills with leach-
ate recycle, were further evidence of removal of organic materxals with a
greater reduction being exhibited for the longer test period in Phase I.
Finally, changes in nitrogen content were also anticipated as the nitrogen
contributed to the nutrient requirements of the biological stabilization
process The rather erratic results were again attributed to difficulties
in obtaining truly representative samples and the distribution of nitrogen
with time as leachate recycle became effective.
Gas Composition
Gas analyses performed during the study period of Phase II (Table lU)
indicated that there was earjy development of methane formers particularly
in Fill k with a generally increasing predominance of the methane fraction of
the gas produced. It is likely that the addition of sewage sludge to Fill 4
enhanced methane formation by providing a biological seed of requisite organ-
isms Because of the physical configuration of the fills and the sampling
techniaue utilized during the studies, no quantitative measurement of total
gas production could be made. However, even after the readily available
organics in the refuse had been removed, methane was detected although the
quantity of gas available for sampling was exceedingly small. Gas measure-
ments were eventually terminated when sampling difficulties became prohi-
bitive.
Admittedly, the measurement of gas production and its composition was
curtailed by techniques employed but were considered to be sufficient to
reflect relative activity within the fills and to provide some support con-
cerning the intrinsic roles of acid and methane formers during the course
of anaerobic stabilization. Although not measured during Phase I, a similar
response in gas production and quality could be presumed to have occurred
at least in the fill with leachate recycle.
75
-------
VOIATIIE ACIDS, pH AND BOD AS MEASURES OF LANDFILL STABILIZATION
Phase I
As discussed previously, the volatile acid concentrations in the recycled
leachate of Fill 2 during Phase I decreased dramatically after 200 days of
recirculation. The rapid decline in volatile acids caused a concomitant rise
in PH; rapidly from 5-2 to 6.6 and then steadily to a maximum of 7.4. Thus
the pH of the system stabilized within the optimum range (6.6-7.4) for the
pH-sensitive methane forming bacteria. As the methane forming phase became
established, a stable anaerobic system was also developed within the fill
with leachate recycle. Because stabilization of refuse in a landfill is de-
pendent upon anaerobic biological action, the development of a stable anae-
robic system in the fill with leachate recycle simultaneously promoted an
efficient stabilization process. In contrast, the environment within the
control fill (Fill l) never exhibited a pH in the optimum range for the develop-
ment of a viable methane forming population and thus, during the study period
of 1063 days, the leachate from the control fill never became stabilized to
the extent of the fill with leachate recycle.
The dramatic reduction in BOD of the leachate from the fill with leachate
recycle during Phase I supported the conclusion that leachate recycle increased
the rate of refuse stabilization. The BOD of the leachate from Fill 2 was
reduced 99.9 percent from its maximum value by the end of the study period.
The leachate from Fill 1 indicated only an 8? percent reduction from its maxi-
mum BOD over the same period. Therefore, in terms of readily available bio-
logically oxidizable organics in the refuse, leachate recycle produced a greater
degree of stabilization as measured by the BOD of the leachate.
Phase II
During Phase II, the volatile acid concentration of Fill 3 was greatly
reduced after 45 days with a corresponding increase in pH from 6.30 at 45
days to 7.00 at 87 days. The methane forming phase became established in
Fill 3 as the PH was adjusted to promote an optimum pH (6.6-7.40) for the
pH-sensitive methane producing bacteria. On the other hand, the fill with
leachate recycle capabilities, pH control, and initial sludge addition
(Fill 4) attained a favorable pH range for methane formation only after about
200 days. This delay was considered due in part to the lag time (two weeks)
between sludge seeding and the initiation of neutralization.
In comparing the results from Fill 3 with Fill 2, it was apparent that
the former attained low concentrations of volatile acid of similar magnitude
to those reached by Fill 2 but in about one-half the time. The leachate from
Fill 3 also had correspondingly higher PH values. Therefore, it was concluded
that Fill 3 had accomplished the same degree of refuse stabilization as Fill 2
but in half the time.
The BOD in the leachate varied greatly between Fills 3 and 4. Fill 3
showed a more rapid reduction in this parameter from its peak value of 7150
mg/1 at 31 days; by the end of the study period the BOD had been reduced
76
-------
substantially and similar in magnitude to the BOD of the leachate from Fill 2
thereby indicating an increased rate of stabilization. The leachate from
Fill k displayed a delayed reduction in BOD which paralleled the reduction
in volatile acids but which was similar in magnitude to the BOD reduction in
Fill 3 at the end of the study period.
In comparing the results from Fill 3 with those from Fill 1 and Fill 2,
the degree of stabilization as characterized by BOD in the leachate indicated
that Fill 3 had achieved approximately the same level in 120 days as Fill 2
had in 280 days and Fill 1 had not by the end of the 1063-da- study period.
Therefore, in terms of readily biologically oxidizable organics in the refuse,
Fill 3 of Phase II achieved, in a shorter period of time, a higher rate of
refuse stabilization than Fill 1 or Fill 2 of Phase I. Using the available
data, the leachate from Fill 3 decreased in BOD to low concentrations and,
therefore, the stabilization experienced by Fill 2 in less than half the time .
This accelerated rate of BOD reduction emphasized the benefits of PH control
and leachate recycle to landfill disposal practices. However, residual con-
centrations of BOD (as well as COD and TOG) and volatile acids possibly caused
by secondary breakdown of more complex materials in the refuse focus attention
on the potential need for residual monitoring and/or treatment.
Because ultimate site use is one of the primary concerns when designing
a sanitary landfill for solid waste disposal, the rate of refuse stabilization
is most important. The ultimate use of many landfill sites must be delayed
for years because of problems with differential settling, gas release uncer-
tainties about leachate production, etc. However, it now appears that when
^eachate recycle and pH control are practiced, biological stabilization of
the readily 'available constituents of the refuse as well as the immediate and
the majority of settlement may be achieved in a much shorter period of time
Therefore, If the value of the landfill site in terms of ultimate use may be
realized sooner, economic conditions may well warrant recycle and pH control
on a large scale with or without residual treatment (See Section VII ) .
EWIRONMEWTAL IMPACT OF LEACHATE RESIDUALS
As indicated by the basic data, residual concentrations of both inorganic
and orLSc materials remained in the leachate from both the Phase I and Phase
II fSls These residuals could impose a detrimental environmental impact
depending upon the nature and relative concentrations of the various leachate
constituents with, respect to the ultimate discharge receptor.
Based upon the results of the experimental studies with leachate recycle,
leachate recycle and/or pH control; the other three fills could then be used
to ertiLte the differences in the leachate quality for ultimate discharge
accountable to the removal of the readily available organic fractions irom
the refuse! Therefore, the results from Fill 1 would yield an indication of
7f
-------
organic pollution potential whereas the results from Fins 2, 3 and h would
be more indicative of residual and also potential inorganic pollution.
Recognizing that the total quantity of leachate produced in the simulated
landfills over the test periods was directly related to the initial moisture
added to the respective fills, the intensity and duration of rainfall, the
amount of evaporation, the quantity utilized during sampling and analysis, and
for Fills 3 and k, the moisture (and chemical) added when neutralization was
used, it was difficult to compute the total mass of constituents extracted
and/or remaining as residuals in the leachate at any time. Moreover, as
leachate accumulated throughout the test periods, some was removed and em-
ployed for the ensuing investigations on alternatives for residual treatment
(Section VII) and the occasional excesses beyond the holding capacity of the
landfill columns and/or collection sumps were removed and stored for future
use These latter excesses did not occur until the readily available organic
materials in the leachate had been removed from Fills 2, 3 and U; biological
treatability studies were performed on accumulations of leachate from Fill 1.
To avoid the presentation of questionable and possibly atypical estimates
of the total mass of pollutants released in the leachate during stabilization
of refuse in the four simulated landfills, it was considered sufficient to
emphasize the dramatic differences in pollutional quality of the leachates
from the four fills exhibited in Tables 10 through 13 at the end of the res-
pective test periods. Whereas the readily available organics had been essen-
tially converted and removed for the fills with leachate recycle, a consider-
able concentration of pollutants remained in the single pass control fijl
(Fill 1) even after over 1000 days of Phase I. Considering that a rainfall/
initial moisture addition equivalent of over 1000 gallons (Table 8) had
passed through the control fill during this period, simple conversion of the
pollutant concentrations from Table 10 would be indicative of the total mass
extracted and potentially escaping to the environment for the particular
refuse and operating mode used during the investigations. Accordingly,
Table 16 presents an estimate of the major constituent materials extracted
from Fill 1 based upon the previous considerations. A similar estimate could
no? be provided for the fills with leachate recycle in either Phase I or
Phase II because of the uncertainties in determining total leachate accumula-
tion at any one time.
Inspection of the estimated masses of materials indicated in Table l6
for the fill without leachate recycle emphasizes the probable need for some
type of attenuation of these constituents if leachate production occurs and
threatens the surrounding environment. The attenuation provided by leachate
recvcle during these studies was considered sufficient and also predictable
with respect to the readily available organic materials, however, depending
upon prevailing circumstances, organic and inorganic residuals and possibly
secondary conversion of more resistant organics may require additional con-
sideration.
-------
Table 16. ESTIMATED INCREMENTAL AND TOTAL MASS (IB POUNDS) OF MATERIAL EXTRACTED FROM FILL 1 DURING PHASE I
Tine since
leacnate production
began, days
lit
39
48
81
116 125 153 173 189 197 228 249 884 312
332
3U7 398 428 1*73 506
COD
BOD5
TOC
Total alkalinity
a a CaCO
Total acidity
as CaCO,
Total hardness
as CaCO_
Phosphate as PO*
Organic nitrogen
Ammonia nitrogen
Nitrate nitrogen
Chloride as cl"
Sulfate as SOi ~
Calcium as Ca
Magnesium as Mg
Manganese as Mn
Sodium as Na
Iron as t'e
Zinc as Zn
Total volatile acids
as Acetic Acid
9.450
5.U70
2.690
l.SSO
1.510
0,980
0.057
0.123
0.122
0.029
0.704
0.181*
0.273
0.057
0.007
O.HtO
0.020
1.912
2.710
1.1*80
0.566
0.1(77
0.326
O.UlU
0.001
0,014
0.044
0.009
0.114
0.037
0.127
0.021
0.003
0.037
0.006
1.276
2.1(70
2.190
0.625
0.1(60
0.334
0. 1(1*0
0.001
0.015
o.o4o
0.021
0.026
0.026
0.112
0.016
0.001
0.031
0.017
1.170
1.510
0.931
0.385
0.282
0.206
0.266
0.001
0.009
0.028
0.012
0.015
0.012
0.087
0.011
0.001
0.019
0.005
0.791*
0.883
0.810
0.206
0.168
0.131
0.143
nil
0.006
o.oi4
0.008
0.007
0.012
0.055
0.005
0.001
0.011
0.007
0.1*95
0.861
0.604
0.209
0.155
0.160
0.129
nil
O.OOlt
O.OlU
0.001
0.025
0.001
0.01*0
0.005
O.OO1
0,011
0.005
0.1*50
1.015
0.971
0.316
0.276
0.203
0.156
nil
O.OO4
0.016
nil
0.01*7
0.006
0.001
0.020
0.007
0.592
1.1*85
1.1*11
0.332
0.390
0.201*
0.210
0.001
0.026
0.015
O.O01
0.025
0.001
0.055
0.007
0.001
0.017
0.023
0.992
0.1*31
0.320
0.089
0.078
0.077
0.062
nil
O.O02
0.005
nil
0.009
nil
0.015
0.002
nil
0.005
0.008
0.210
2.700
2.1(50
0.592
0.520
0.1*93
0.1(93
0.001
0.001
0.058
o.ol(6
0.003
0.133
0.018
O.OOl)
0.031*
0.044
1.1*1
7.2.1*0
5.1*10
1.590
1.21*0
1.61(0
1.380
O.OOl
0.018
0.126
0.122
0.3UO
0.050
0.008
0.091
0.177
3.780
2.650
2.210
0.56l
0.1(57
0.527
o.424
nil
0.002
0.01(0
0.057
0.104
0.016
0.003
0.028
0.053
1.230
1.720
1.O20
0.375
0.194
0.3i9
0.269
nil
0.005
0.029
0.034
0.060
0.008
0.002
0.016
o.ol»6
0.770
2.660
1.970
0.740
0.365
0.510
0.820
nil
0.016
0.017
0.027
0.1*
0.038
0.003
0.02l(
0.027
1.370
l.M(0
1.160
0.330
0.1U5
0.21(0
0.319
nil
0.011
0.005
0.028
0.078
0.019
0.002
0.013
0.023
0.624
2.260
1.630
0.510
0.1(13
0.31*0
0.1(12
nil
0.013
0.019
o.ol(8
0.094
0.015
0.002
0.015
0.063
1.100
2.860
1.820
0.610
O.ltOO
0.1(97
0.1(76
nil
0.013
0.021
0.061
0.101
O.Oll*
0.002
0.029
0.091
1.190
0.61(2
0.396
0.680
0.336
nil
0.006
0.031
0.025
0.088
0.008
0.004
0.021
0.038
0.969
0.511*
0.360
0.139
0.080
0.160
0.062
nil
0.002
O.O06
0.006
0.018
O.OO2
0.001
0.005
0.003
0.214
1.062
0.625
0.287
0.177
0.230
0.186
nil
0.015
0.010
0 001
0.017
0.01(1
O.O05
0.001
0.015
0.035
0.324
0.630
O.U30
0.193
0.116
0.140
0.122
nil
0.003
0.006
nil
0.010
0.027
0.003
0.001
0.009
0.016
0.290
1.710
1.160
0.560
0.390
0.330
0.300
nil
0.009
0.016
nil
0.025
0.067
0.009
0.001
0.028
0.054
0.826
1.080
0.880
0.360
0.270
0.190
0.180
nil
0.006
0.011
nl 1
nix
0.022
0.031
O.OO2
O.C01
0.017
o.o4o
0.533
-------
CD
o
Table 16 (continued) ESTIMATED 7NCRKMENTAL AND TOTAL MASS (IN I'OUNDS) OK MATERIAL EXTRACTED FROM FILL 1 DURING PHASE I
Time since
leachate production
began, days
con
BOD
TOC
Total alkalinity as CaCO
Total acidity a;; CaCO,
Total hardness as CaCO
Phosphate as PO,
Organic nitrogen
Ammonia nitrogen
Nitrate nitrogen
Chloride as Cl~
Sulfate as SO, *
Calcium as Ca
Magnesium as Mg
Manganese as Mn
Sodium as Na
Iron as Fe
Zinc as Zn
'Ratal volatile acids
as Acetic Acid
530
1.550
0.9*0
0.1*20
0.390
0.360
0.230
nil
0.017
O.OO7
nil
0.032
0.039
O.OOU
0.001
0.028
0.055
0.803
556
1.11*0
0.710
0.1*1*0
0.380
0.310
0.2"0
nil
0.016
0.005
nil
0.037
0.032
O.OOI*
0.001
0.031
0.050
0.008
0.610
606
l.llOO
0.960
0.320
0.1(7O
0.380
0.260
nil
0.013
O.OOU
nil
0.031
0.035
0.005
0.001
0.063
0.06S
0.009
0.750
636
1.830
1.250
0.620
0.51*0
0.700
0.550
nil
0.018
0.002
nil
O.OltO
o.cAs
0.006
0.001
0.070
0.075
0.003
0.960
67?
1.1*80
1.110
0.570
0.530
0.1(50
0.200
nil
O.OOlt
0.00?
nil
0.022
0.028
0.003
0.001
0.061
0.063
0.003
0.612
70l*
0.370
0.250
0.150
0.170
0.120
0.056
nil
0.002
O.O01
nil
O.O08
0.011
0.001
nil
0.016
0.018
0.001
0.210
758
0.900
0.51*0
0.280
0.350
0.220
0.310
nil
nil
0.003
nil
0.051
0.039
0.006
0.001
0.013
0.100
0.003
0.370
785
0.31*0
0.220
0.110
0.097
0.120
0.130
nil
0.003
0.001
nil
0.011
0.015
0.002
nil
o.ooi*
o.ol*8
0.00]
0.150
820
0.610
0.300
0.170
0.11(0
0.170
0.250
nil
o.ooi*
O.OO2
nil
0.017
0.035
o.ooi*
0.001
0.008
0.081
0.002
0.220
858
0.190
0.1^0
o.ogi(
0.086
0.077
0.110
nil
o.oor>
0.001
nil
0.007
0.015
o.ooc
nil
o.ooi*
0.038
0.001
0.130
871*
0.270
0.12"
0.110
0.095
0.110
0.11*0
nil
O.O02
0.001
nil
0.009
0.019
0.003
nil
0.005
o.ol*8
0.001
0.110
895
0.530
0.260
0.21(0
0.302
0.210
0.310
nil
0.005
0.002
nil
0.021
0.01(1
0.006
0.001
0.011
0.1OO
0.002
899
0.050
0.027
0.015
0.013
0.011
0.018
nil
nil
nil
nil
nil
0.002
nil
nil
0.001
O.OOlt
nil
0.020
928
0.720
0.1.60
0.300
0.190
0.190
0.270
nil
0.002
0,001
nil
O.OO5
0.035
0.005
0.003
O.OO7
O.Ofio
O.O06
0.580
<*l*9
0.8.30
0.1*80
0.360
0.210
o.;<3o
0.330
nil
0.003
0.001
nil
0.008
0.035
0.004
0.003
0.006
0.085
0.006
0.510
961.
0.056
0.032
0.023
0.012
O.Oll*
0.020
nil
nil
nil
nil
nil
O.OO2
nil
nil
nil
0.006
nil
0.032
972
0.081
0.051
O.OW*
0.021
0.029
0.01*3
nil
nil
nil
nil
0.001
0.002
nil
nil
nil
0.013
nil
0.056
979
0.077
O.Ol*3
0.035
0. 0?2
0.029
0.033
nil
nil
nil
nil
0.001
0.002
nil
nil
nil
0.010
nil
O.OUl
993
O.U80
0.290
0.230
0.110
0.11*0
0.210
nil
0.002
nil
nil
0.0*
0.013
0.002
0.005
0.003
0.063
0.002
0.250
1007
0.120
0.075
0,057
0,030
0.01*0
0.058
nil
nil
nil
nil
0.001
0.003
0.001
nil
0.001
0.010
nil
0.061
1028
0.320
O.SOO
0.160
0.077
0.095
0.160
nil
0.001
nil
nil
O.OO2
0.006
0.015
nil
0.002
0.053
0.001
0.120
101*2
0.190
O.lUO
0.100
0.037
0.068
0.096
nil
0.001
nil
nil
0.001
o.ooi*
0.001
nil
O.OOI
0.033
nil
0.071*
" 1063a
0.150
0.072
0.071
0.028
0.01*8
0.057
nil
0.001
nil
nil
0.001
0.001*
O.OOI
nil
0.00]
0.016
0.001
0.079
Total
63.030
"»3-990
17.830
12.970
13.510
12.61tO
0.1*19
0.726
1.763
2.629
0.1*08
0.081
0.972
1.937
0.139
29.1(70
"values generated from trend in precipitation data for days 1060 to 1093 (day 0 for leachate production corresponds to day 33 f
Values for Zinc not determined until 556 days after leachate production began.
'ollowing Initial refuse placement-refer to Table 8).
-------
SECTION VII
SEPAEATE TREATMENT OF LEACHATE AND 1EACHATE RESIDUALS
INTRODUCTION
In many areas where ground or surface waters are used for domestic or
industrial purposes, the landfill method of solid waste disposal has been
discouraged because of possible production and uncontrolled release of
leachate. Since leachate may be extremely high in BOD and other pollutants,
even if it were contained and collected, some questions would arise con-
cerning its treatability by either conventional or special treatment methods.
The studies described heretofore have demonstrated the changes in leachate
quality which may occur with time and also the benefits derived from on-site
treatment of the leachate by recycle through the landfill. The major
benefits so derived include more rapid and predictable stabilization of the
readily available organic refuse constituents as well as a dramatic reduction
in pollutant strength in the leachate to levels such that the leachate could
be amenable for discharge or for release for additional treatment within a
more acceptable time frame. This stabilization and/or reduction in pollutional
characteristics of the leachate could be greatly facilitated by initial neu-
tralization during recycle of the leachate in order to control the pH of the
environment within an acceptable range for the immediate development of the
methane forming organisms. In essence, the landfill itself is thereby used
as a controlled anaerobic treatment system much analogous to an anaerobic
trickling filter.
Assuming that the results from the simulated landfills used during the
experimental studies can be related to large-scale landfill operations, it
appears that recycled leachate can reach, in a reasonable length of time, a
quality suitable for consideration for ultimate release into noncritical
receiving waters. In addition, this study has indicated that the length
of time required to reach the desired quality of leachate can be lessened by
initial neutralization of the recycled leachate. Whether residual organics
or such inorganic pollutant residuals as hardness, chloride, calcium, etc.
require additional treatment will depend upon the condition of the receiving
waters and/or regulatory requirements.
It would also seem plausible to use leachate recycle (with or without
pH control) in combination with external treatment. Since most landfill
sites are not near municipal wastewater collection and treatment systems, a
logical receptor for ultimate discharge, it might be advantageous to use
portable package-type waste treatment facilities in conjunction with leachate
recycle at the site. Leachate recycle through the landfill and the treatment
facility would then be beneficial both in maintaining a constant flow ani in
81
-------
providing removal of specific pollutant constituents. The effluent could
eventually be discharged intermittently to the receiving waters at the most
advantageous and least detrimental times. When the refuse constituents in
the landfill has been stabilized and the leachate quality had reached an
acceptable level for discharge, the portable plant could be then moved to
another location. Such a stabilization/leachate treatment scheme working
in consort may well prove to be the most reliable and economical approach
to controlled landfill operation with environmental quality protection.
Because of the need for screening and determining the relative appli-
cability of separate and/or combined treatment schemes for raw leachate or
leachate residuals, separate biological and physical-chemical leachate treat-
ment studies were initiated. The alternatives selected and presented here-
after were based upon the premise that a relatively fresh and usually strong
leachate with high organic pollutant characteristics would best be treated
by biological methods possibly followed by physical-chemical methods for
removal of residual organics and/or inorganics, color, odor and various bio-
logical impurities. Physical-chemical methods would also be most applicable
for an older leachate devoid of all but residual organic pollutants but con-
taining certain possibly detrimental inorganic constituents. The systems
used during the separate treatability studies were chosen to simulate conven-
tional biological and physical-chemical treatment methods and the accumulated
data were analyzed in accordance with accepted techniques and the analytical
procedures presented previously in SECTION IV.
SEPARATE BIOLOGICAL LEACHATE TREATMENT
Separate studies of both anaerobic and aerobic biological treatment were
performed in a complete-mix reactor system similar to that indicated in Figure
22, The leachate used in both studies was a mixture of leachate from the con-
trol column of Phase I (Fill l) and a local landfill. The average charac-
teristics of the two leachate samples employed during the studies are indicated
in Table 17.
Table 17. CHARACTERISTICS OF LEACHATE USED DURING SEPARATE
BIOLOGICAL TREATMENT
Leachate Anaerobic Aerobic
characteristic treatment treatment
PH
COD, mg/1
BOD , mg/1
TOC; mg/1
Suspended solids
Total, mg/1
Volatile, mg/1
5-1
6,000
3,700
2,100
1,100
300
7.0
500
260
320
625
160
82
-------
MOTOR CONT R Ol I E.R
CD
u>
I E V F. I
C ONT R Ol I E R
PUMP SPEED
CONTROltER
TEMPERATURE
CONT R Ot
CULTURE
MEDIA —»
MOTOR
E F Fl U E N T
FIGURE 22 COMPLETELY MIXED, CONTINUOUS FLOW REACTOR SYSTEM
-------
Table 1?. (Continued) CHARACTERISTICS OF LEACHATE USED DURINf
SEPARATE BIOLOGICAL TREATMENT
Leachate Anaerobic Aerobic
characteristic treatment treatment
Calcium, mg/1
Magnesium, mg/1
Potassium, mg/1
Sodium, mg/1 _
Phosphate, mg/1 POJ"
Total volatile acids,
mg/1 as acetic acid
200
6^
3*8
313
-
2,700
100
35
2014.
425
0.7
kio
A more concentrated leachate representative of a landfill undergoing
initial biological stabilization with the production of high volatile acids
concentrations was intentionally used during the anaerobic treatability
studies, partially to emphasize the logic of choice of treatment method for
such a leachate and also to provide some confirmation of the results obtained
during Phase I and Phase II of the leachate recycle studies. A less concen-
trated and more characteristic of an older or at least partially treated
leachate was intentionally chosen for the aerobic treatability studies since
aerobic treatment would normally be more logically applied under such cir-
cumstances.
The data from the anaerobic treatability studies are included in Table 18
and Figure 23. Corresponding data from the aerobic treatability studies are
included in Table 19 and Figure 2k, In either case, the data indicated good
removals of the pollutant components of the leachate as measured by COD, BOD ,
or TOG and volatile acids with acceptable correlations between these para-
meters.
The graphical displays resulting from reciprocal plots of the data
(Figures 23 and 2*0 yielded curves for the indicated parameters together with
kinetic parameters in accordance with continuous culture theory analysis.
The results are typical of results expected when the anaerobic and aerobic
treatment processes applied to a biologically degradable substrate are com-
pared. Accordingly, washout occurred in about 1.3 days and 1.8 hours, res-
pectively, in the anaerobic and aerobic systems; a reflection of the relative
differences in generation times between anaerobic and aerobic organisms.
Similarly, biological solids yield for the anaerobic system was half of the
corresponding yield for the aerobic system^ a consequence of less conversion
of substrate to biomass in the former process.
During the anaerobic treatability studies, the pH ranged between 6.9
and 7.6 which was considered satisfactory for good conversion of the volatile
acids to methane and carbon dioxide. Once active anaerobic decomposition had
been established, gas production ranged between about 9 and 17-4 cu. ft. per
pound of BOD destroyed (about 6 to 11 cu. ft. per pound of COD destroyed)
-------
Table 18. RESULTS OF SEPARATE ANAEROBIC BIOLOGICAL LEACHATE TREATMENT IN
CONTINUOUS CULTURE WITHOUT SOLIDS RECYCLE
Liquid
retention
time, days
ob
0.10
0.16
0.33
1.0
5.0
10.0
15.0
COD,a
mg/1
6000
6010
5990
5l)-00
4020
1090
6?0
iko
BOD ,
mg/la
3700
3^10
3^00
4100
2600
4-70
80
75
Total volatile
acids, mg/1 as
TB:_COOH
2700
2600
2682
2915
1206
187
109
63
Volatile
suspended
solids, mg/1
300
260
294
315
450
700
400
1+90
pH
5.1
6.9
7.0
7.3
7.4
7.5
7.6
7.1
Gas production
cu.ft./lb.
BOD removed
nil
0.9
0.7
4.6
9-9
9.3
17.4
%
CHU
80.2
82.5
82.1
83.2
7^.6
Co
vn
Filtered sample
Average influent concentration for all retention times.
-------
7000
6000 RS-
o
o> 5000
E
9
< 4000
ui
O 3000(-A
Q
Z
O
00
O
O
O
UI
u.
u_
UI
2000
1000
LEGEND:
CHEMICAL OXYGEN DEMAND
5-DAY BIOCHEMICAL OXYGEN DEMAND
, TOTAL VOLATILE ACIDS
VOLATILE SUSPENDED SOLIDS
KINETIC PARAMETERS:
pmax = 1.1 day'1
kd = 0.175 day'1
Ks = 232 mg BOD5/I
Y = 0.25 mg VSS/mg BOD5 Removed
-^
O)
-|8OO E
3456789 10
LIQUID RETENTION TIME, days
11 12 13 14 15
FIGURE 23
ANAEROBIC BIOLOGICAL TREATMENT OF
LEACHATE IN CONTINUOUS CULTURE
86
-------
Table 19. RESULTS OF SEPARATE AEROBIC BIOLOGICAL LEACHATE TREATMENT IN CONTINUOUS
CULTURE WITHOUT SOLIDS RECYCLE
Liquid
retention
time, hours
oa
2.3
3-0
5-5
8.0
COD,
mg/1
500
290
250
205
210
BOD
rag/1
260
75
U2
36
30
TOG,
mg/1
320
2^0
200
lUo
150
Suspended solids
Total,
mg/1
625
975
1000
930
870
Volatile ,
mg/1
160
215
250
300
310
PH
7.0
8.0
8.1
8.2
8.3
Calcium,
mg/1
100
3^
29
25
25
Magnesium,
mg/1
35
31
3^
30
32
Potassium,
mg/1
204
3M
164
i4o
164
Sodium,
mg/1
425
425
^25
CO
Average influent concentration for all retention times.
-------
lOOOr
900-
800 -
700
600
500
UJ
" 300-
it
UJ
200
IOC-
S'DAY BIOCHEMICAL OXYGEN DEMAND
CHEMICAL OXYGEN DEMAND
TOTAL ORGANIC CARBON
TOTAL SUSPENDED SOLIDS
VOLATILE SUSPENDED SOLIDS
KINETIC PARAMETERS:
Umax * 0.66 hour"1
kd ' 0.014 hour'1
Ks ; 41.3 mg BOD5 / I
Y - 0.5 mg VSS/mg BOD5 removed
ec : 1.8 hours
J_
J_
1 2 3.4 5
LIQUID RETENTION TIME, hours
FIGURE 24
AEROBIC BIOLOGICAL TREATMENT
OF LEACHATE IN CONTINUOUS
CULTURES
88
-------
Mi
which was in agreement with the results of Boyle and Ham . Total alka-
linity varied between 680 and 2800 mg/1 as CaCO which was also considered
sufficient to counteract the pH-depressing influence of the volatile acids
throughout the study period.
In general, the gas produced during the anaerobic biological treat-
ability studies was higher in methane content than normally reported for
anaerobic sludge digestion. However, assuming the studies were a reasonable
representation of expected gas yields, even at lower (60-7O/0) methane contents,
energy recovery from the gas produced during conversion of the leachate would
be an attractive possibility. The relative abundance of methane in the gas
was probably accountable in part to the nature of the individual volatile
acids which made up the primary available organic constituent of the leachate.
Normally the total volatile acids consisted of 33, Uo, 17 and 10 percent
acetic, propionic, butyric and valeric acids, respectively. In addition, as
the pH increased, a greater carbon dioxide content and alkalinity existed
in the aqueous phase of the system thereby seemingly increasing the propor-
tion of methane in the gas.
PHYSICAL-CHEMICAL LEACHATE TREATMENT
k2-l&
The efforts of several investigators have indicated that chemical
coagulation and oxidation are not effective procedures for removing dissolved
and particularly organic pollutants from leachate. These observations were
further confirmed by Karr^ and Mingledorff^° using lime and alum supplemented
with a non-ionic polyelectrolyte (PURIFLOC N-17). Removals of BOD and COD
were generally less than 25 percent. Chemical oxidation with chlorine and
permanganate required very high dosages (1000-1200 mg/l) to effect similar
removals^"2»^5 as was further demonstrated by Boyle and Hanr1. Therefore,
high oxidant requirements coupled,with the vast quantities of solids pro-
duced during chemical coagulation and in need of further treatment and/or
disposal precluded consideration of these methods for treatment of high
organic strength leachates.
Separate Treatment of Leachate Residuals
Since inspection of the quality data for effluents from the leachate
recycle and/or separate biological treatability studies indicated organic
and inorganic residuals which may be unacceptable for ultimate discharge,
adjunct investigations on other physical-chemical treatment alternatives
for residuals treatment were initiated. The alternatives were narrowed to
treatment for organic and inorganic residuals and therefore ion exchange and
adsorption seemed plausible choices.
Cation Exchange Treatment of Leachate Residuals
To ascertain the effectiveness of ion exchange treatment of leachate
residuals, some of the effluent from the separate aerobic biological leachate
treatment studies was collected and subjected to batch treatment with increa-
sing dosages of cation exchange resin (DOWEX, 50W x 8, H form). As indicated
89
-------
in Table 20 and Figure 25, excellent cation removal was achieved with the
divalent calcium and magnesium preceeding the removal of monovalent sodium
and potassium.
Table 20. CATION EXCHANGE TREATMENT OF LEACHATE RESIDUALS
Effluent
analysis
Resin dosage, g/1
1.3 2.0 5.0 10.0
25.0
PH
Alkalinity, mg/1 CaCO
TDS, mg/1 J
Specific conductance
vmho/cm
Calcium, mg/1
Magnesium, mg/1
Potassium, mg/1
Sodium, mg/1
Acidity, mg/1 CaCO
COD, mg/1 ^
8.1
560
1040
2100
29
18.8
100
260
0
185
7.6
500
9kk
1920
20
9.2
93
262
105
166
7-3
ij-30
838
1790
7*
^.5
86
2^0
l?:o
166
6.9
130
73^
890
k.9
0.2
32
130
210
2.9
352
960
k.k
0.1
8.8
ko
koo
150
2.5
25^
1360
1.0
2.6
15.0
hjo
166
aDOWEX 50W x 8, H form; one hour exposure time,
In an attempt to monitor overall removal performance, several common
parameters were used including total dissolved solids (TDS), pH, alkalinity
or acidity, specific conductance and COD. Changes in these parameters are
also included in Table 20 and some of these data are displayed graphically
on Figures 26 and 27. Analysis of these data indicated that neither alka-
linity or specific conductance were good monitors at high resin dosages where
the pH had decreased and the acidity increased during exchange as the hydro-
gen ions were released from the resin. Indeed, specific conductance actually
increased despite a steady decrease in total dissolved solids. Therefore,
TDS concentration was considered the only acceptable overall cation removal
indicator parameter reflecting a 75 percent removal by cation exchange alone.
The remaining solids (and COD) indicated a possible need for additional
treatment for removal oxygen demanding constituents as well as anions.
Mixed Resin Ion Exchange Treatment of Leachate Residuals
Since anion residuals appeared after the cation exchange studies, addi-
tional batch investigations with increasing dosage| of both anion and cation_
exchange resins (equal amounts of DOWEX 50W x 8, H form and DOWEX 1x8, OH
form) were conducted also on some of the effluent from the separate aerobic
biological leachate treatment studies. The results of these investigations
are included in Table 21 and Figures 28 and 29.
90
-------
LEGEND:
Ca
A A Mg
a a K
• • Na
RESIN: DOWEX SOW, H+ FORM
EXPOSURE TIME: ONE HOUR
300
250
200
150
CD
E
z
Q
100
50
468
RESIN DOSAGE, g/l
12 25
FIGURE 25
REMOVAL OF METALS FROM AEROBIC
BIOLOGICAL LEACHATE TREATMENT
EFFLUENT BY CATION EXCHANGE
91
-------
Table 21. MIXED RESIN TREATMENT OF LEACHATE RESIDUALS
Effluent
analysis
Resin dosage, g/1
1.3 2.0 5.0 10.0
25.0
PH
Alkalinity, mg/1 CaCO
TDS, mg/1 *
Specific conductance,
ymho/cm
Calcium, mg/1
Potassium, mg/1
Sodium, mg/1
Chloride, mg/1
Sulfate, mg/1 S07
Nitrate, mg/1 N 4
Total Phosphate, mg/1 P
COD, mg/1
8.5
520
926
lU6o
13.2
12.6
198
130
k.Q
o.h
0.1
120
8.1
1*05
728
1350
6.6
6.0
178
105
nil
nil
— _
68
7.7
260
613
1C&5
2.5
1.1
ll£
95
—
nil
—
—
7-5
100
336
U80
0
0.08
1*6
62
—
nil
___
50
5-0
<5
118
13
1.2
0.05
0.35
5
—
nil
—
5.5
<5
82
3
0
0.05
0.35
<5
—
nil
—
—
amounts of DOWEX 50 x 8, H form and DOWEX 1x8, OH~ form; one hour
exposure time.
The data indicated that all measured ionic impurities were removed,
again in order of resin selectivity. The decrease in pH was not as dramatic
with the anion resin present and both TDS and specific conductance could be
used as a measure of overall performance. However, since some impurities
still remained, TDS was probably the more indicative parameter of actual
effluent quality reflecting both ionic and organic residuals. To be used
as a predictive parameter, ion exchange could be considered a form of sorption
from solution and the equilibrium distribution of ions between resin and solu-
tion phases could be expressed by conventional isotherm analysis as used for
carbon adsorption in the succeeding section.
Carbon Treatment of Leachate Residuals
Since organic residuals remained in the effluents from biological leachate
treatment, some of the effluent from the separate aerobic biological leachate
treatment was also subjected to batch treatment with powdered activated carbon
(NUCHAR C-190-N). Predetermined dosages of carbon were added to the effluent,
mixed for 30 minutes and then removed by filtration through Whatman No. 2
filter paper. Filtrate analyses yielded the data included in Table 22.
92
-------
Resin: DOWEX 50 W H+ FORM
EXPOSURE TIME: ONE HOUR
RESIN DOSAGE, g/l
12 25
FIGURE 26 EFFECT OF CATION EXCHANGE ON pH AND
ACIDITY OF EFFLUENTS FROM AEROBIC
BIOLOGICAL TREATMENT OF LEACHATE
93
-------
1200
LEGEND: o—o TOTAL DISSOLVED SOLIDS
SPECIFIC CONDUCTANCE
RESIN: DOWEX SOW, H+ FORM
EXPOSURE TIME: ONE HOUR
6 8
DOSAGE, g/l
12 25
FIGURE 27
EFFECT OF CATION EXCHANGE ON TOTAL
DISSOLVED SOLIDS AND SPECIFIC
CONDUCTANCE OF EFFLUENT FROM AEROBIC
BIOLOGICAL TREATMENT OF LEACHATE
-------
600r
PH
ALKALINITY
-o
Ca
Mg
K
• • Na
• • Cl
Resins: DOW EX 50 W, H+ FORM
DOW EX 1, OH' FORM
Exposure Time: ONE HOUR
9
8
7
6
5
4
3
20
16
12
o>
a
(0
O
468
RESIN DOSAGE, g/l
10
12 25
FIGURE 28
MIXED RESIN ION EXCHANGE TREATMENT
OF EFFLUENT FROM AEROBIC BIOLOGICAL
TREATMENT OF LEACHATE
95
-------
Table 22. CARBON TREATMENT OF LEACHATE RESIDUALS
Effluent
analysis
0
500
Carbon dosage, mg/1
1,000 2,000 U,000
10,000
COD, mg/1
TDS, mg/1
Specific conductance,
y mho/ cm
18U
976
1310
92
850
1250
64
886
1390
55
916
l4Uo
18. k
980
1535
18 A
1160
1770
^estvaco NUCHAR C-190-N; 30 minutes exposure time.
The data in Table 22 indicated that COD removals were very good and a
Freundlich isotherm and predictive equation could be developed as shown on
Figure 30. At initial contact with the effluent, each gram of carbon ad-
sorbed 5^0 mg of COD. However, as indicated in Table 22, both specific
conductance and TDS increased as carbon dosages increased. These increases
were attributed to leaching from the carbon and were considered of sufficient
significance to warrant additional scrutiny as demonstrated in the following
section.
Carbon Treatment After Mixed Ion Exchange Treatment of Leachate Residuals
To confirm the causes of problems with leaching of impurities during
carbon adsorption, additional studies were performed on activated carbon
treatment after application of mixed resin ion exchange treatment of some
of the effluent from separate aerobic biological leachate treatment. The
same exchange resins and carbon were employed as before and the results of
these studies were tabulated and are included in Table 23.
As indicated in Table 23, dosages of ion exchange resin were varied
and the carbon dosage was maintained at kOOO mg/1 which was the concentration
previously yielding a constant effluent COD (Table 22). The results of addi-
tion of the ion exchange resins were very similar to the previous batch
studies (Table 21) with respect to ion removal, a steady decrease in TDS and
specific conductance, pH and COD. However, with the addition of carbon after
this ion exchange treatment, the COD was removed but significant increases
in TDS and specific conductance were noted. Corresponding increases in pH,
sodium, potassium and sulfate were also noted together with some reduction
in calcium and magnesium after carbon treatment.
Since the treatment of leachate residuals by ion exchange followed by
carbon adsorption resulted in unfavorable increases of inorganic dissolved
solids apparently originating from the carbon, these studies indicated that
if residual treatment is necessary, the treatment sequence should be reversed
with carbon adsorption preceding ion exchange. Accordingly, Figure 31
suggests a possible scheme for on-site treatment of leachate from sanitary
96
-------
E
a.
uT
O
I
O
O
iu
0.
(0
TOTAL DISSOLVED SOLIDS
• SPECIFIC CONDUCTANCE
Resins : DOWEX 50 W, H+ FORM
DOWEX 1, OH' FORM
Exposure Time: ONE HOUR
O)
E
o
o
o
UJ
O
CO
O
400-
200-
468
RESIN DOSAGE, g /I
25
FIGURE 29
EFFECT OF MIXED RESIN ION EXCHANGE
ON DISSOLVED SOLIDS AND SPECIFIC
CONDUCTANCE OF EFFLUENT FROM AEROBIC
BIOLOGICAL TREATMENT OF LEACHATE
97
-------
1.00
0.50-
cc
g
O)
o °-10t
IU
O
UJ
*
O
8
o>
04)5
0.01
I i i i
1 r
INTERCEPT = 0.54
EXPOSURE TIME: O.5 HOURS
i i i
'C0 =184
3 5 10 50 100
C(COD RESIDUAL), mg/l
FIGURE 30 THE FREUNDLICH ISOTHERM OF CARBON
ADSORPTION ON EFFLUENT OF AEROBIC
BIOLOGICAL TREATMENT OF LEACHATE
500
98
-------
Table 23. COMBINED MIXED RESIN ION EXCHANGE AND CARBON
TREATMENT OF IEACHATE RESIDUALS
Effluent
analysis
Resin dosage, g/la
1.3 2.0 5-0 10.0
25.0
pH, Initial
Final
COD, mg/1
Initial
Finalb
TDS, mg/1
Initial
Finalb
Specific conductance,
fjmho/cm
Initial
Finalb
Calcium, mg/1
Initial
Finalb
Magnesium, mg/1
Initial
Finalb
Potassium, mg/1
Initial
Final
Sodium, mg/1
Initial
Finalb
Sulfate, mg/1 SO ^
Initial
Finalb
8.1
180
--
1100
1800
18.0
--
16.8
—
104
--
170
—
0
--
8.2
8.6
125
0
912
898
1745
1800
15.0
11.4
9.0
8.4
96
104
165
195
—
76
7.8
8.1;
115
0
864
862
1445
1650
8.7
5-1
^.5
3.1
84
86
155
185
80
7-5
8.1
—
0
576
508
768
960
1.8
1.0
0.7
o.4
42
46
105
120
_ —
80
4.9
7.1
57.3
0
146
164
21
274
f
0.6
0.6
0.1
0.3
o.4
8.0
3-3
31
_ _
72
4.9
6.7
49.2
0
64
294
5.5
274
,. /-
0.6
0.8
0
0.34
0
6.7
1.1
30
~~
80
a Equal amounts of DOWEX 50W x 8, H
exposure time.
4.0 g/1 NUCHAR C-190-N; 30 minutes
form and DCWEX 1x8, OH~ form; one hour
exposure time.
99
-------
landfills including both biological and physical-chemical processes. Any
accumulated waste solids could logically be returned to the landfill for
ultimate disposal. Leachate recycle with possible facilities for neutrali-
zation could be substituted in the indicated treatment scheme for separate
biological treatment. The ultimate choice and extent of treatment as well
as its period of application would be a function of the nature of the leachate
and local environmental considerations. With the proposed scheme, effluent
of any desired inorganic or organic quality could be achieved simply by mani-
pulating the treatment methods.
100
-------
Clarification
Biological
Treatment
Solids Recycle
.Raw Leachate
..Waste Solids
Recovery or
XFinal Disposal
Anion
Exchange
Regenerant
1O % NaOH
Recovery or
Xplnal Disposal
FIGURE 31 POSSIBLE SCHEME FOR ON-SITE TREATMENT
OF NON-RECYCLED LEACHATE
101
-------
SECTION VIII
REFERENCES
1. Fungaroli, A. A., "Hydrologic Considerations in Sanitary Landfill
Design and Operation," In: Proceedings of National Solid Wastes
Management Conference, University of Houston, 1970, p. 208-217.
2. Proceedings of the Symposium on Ground Water Contamination, Robert A.
Taft Sanitary Engineering Center, Cincinnati, Ohio, Tech. Report w6l-5,
Public Health Service, U. S. Dept. of Health, Education, and Welfare,
1961.
3. Anderson, J. R., and J. N. Dornbush, "Influence of Sanitary Landfill on
Ground Water Quality," Jour. Amer. Water Works Assn., 59, No. 4, p. 457-
470 (1967). —
4. Hughes, G. M., R. A. Landon, and R. N. Farvolden, 'Summary of Findings
on Solid Waste Disposal Sites in Northeastern Illinois," Illinois Geol.
Survey, Envir. Geology Notes, 45, 25 p. (1971).
5. Hughes, G. M., R. A. Landon, and R. N. Farvolden, "Hydrogeologic Data
from Four Landfills in Northeastern Illinois," Illinois Geol. Survey,
Envir. Geology Notes, 26, 4-2 p. (1969).
6. Hughes, G. M., "Selection of Refuse Disposal Sites in Northeastern
Illinois," Illinois 'Geol. Survey, Envir. Geology Notes, 17, 15 p.
(1967).
7. Hughes, G. M., R. N. Farvolden, and R. A. Landon, "Hydrogeology and Water
Quality at a Solid Waste Disposal Site," Illinois State Geological Survey,
Naperville, Illinois, Special Report, 15 p. (1969).
8. Hughes, G. M., R. N. Farvolden, and R. A. Landon, "Hydrogeology of Solid
Waste Disposal Sites in Northeastern Illinois," Interim Report to USPHS,
137 P. (1969).
9. Coe, J. J., "Effect of Solid Waste Disposal on Ground Water Quality,"
Jour. Amer. Water Works Assn., 62, No. 12, p. 776-783 (1970).
10. Calvert, C., "Contamination of Ground Water by Impounded Garbage Water,"
Jour. Amer. Water Works Assn., 24, No. 2, p. 266-270 (1932).
11. Carpenter, L. V., and L. R. Setter, "Some Notes on Sanitary Landfills,"
Amer. Jour. Pub. Health, 30, No. 4, p. 385-393 (1940).
102
-------
12. Lang, A., "Pollution of Ground Water by Chemicals," Jour. Amer. Water
Works Assn. [abs.], 33_, Wo. 11, p. 2075-2076 (I94l).
13. Davison, A. S., "The Effect of Tipped Domestic Refuse on Ground Water
Quality," Jour. Soc. Water Treatment and Examination, 18, Part 1,
P. 35-41 (1969).~~
14. Hopkins, G. J., and J. R. Popalisky, "influence of an Industrial Waste
Landfill Operation on a Public Water Supply," Jour. Water Poll. Control
Fed., 142, No. 3, p. 431-436 (1970).
15- Remson, J., A. A. Fungaroli, and A. W. Lawrence, 'Water Movement in an
Unsaturated Sanitary Landfill," Jour. San. Engr. Div., Amer. Soc. Civil
Engineers, 94, SA2, p. 307-317 (1968).
16. Merz, R. C., and R. Stone, "Special Studies of a Sanitary Landfill,"
Final Summary Report and Third Progress Report to USPHS, 51 p. (1968).
17. Qasim, S. R., and J. C. Burchinal, "Leaching from Simulated Landfills,"
Jour. Water Poll. Control Fed., 1+2, No. 3, p. 371-379 (1970).
18. Qasim, S. R., and J. C. Burchinal, "Leaching Pollutants from Refuse Beds,"
Jour. San. Engr. Div., Amer. Soc. Civil Engineers, SA1, p. 1+9-58 (1970).
19- Fungaroli, A. A., and R. L. Steiner, "Laboratory Study of the Behavior of
a Sanitary Landfill," Jour. Water Poll. Control Fed. . 4_3, No. 2, p. 252-
267 (1971).
20. "Report on the Investigation of Leaching of a Sanitary Landfill," Calif.
Water Poll. Control Board, Publication No. 10, 91 p. (1954).
21. Emrich, G. H. and R. A. Landon, "Generation of Leachate from Landfills
and Its Subsurface Movement," Proc. Northeastern Regional AntiPollution
Conference, Univ. of Rhode Island, p. 57-63 (1969).
22. Emrich, G. H., "Guidelines for Sanitary Landfills - Ground Water and
Percolation," Compost Science, 13., No. 3, p. 12-15 (1972).
23. "Sanitary Landfill," ASCE Manual of Practice No. 39 (195.9).
24. ''Pollution of Water by Tipped Refuse," Rept. Tech. Committee on Experi-
mental Disposal of House Refuse in Wet and Dry Pits, Ministry of Housing
and Local Government, Her Majesty's Stationery Office, London, l4l p.
(1961).
25. Eliassen, R., "Decomposition of Landfills," Amer. Jour. Pub. Health,
32, Wo. 9, P. 1029-1037 (1942).
26. Pohland, F. G., and D. E. Bloodgood, ''Laboratory Studies on Mesophilic
and Thermophilic Anaerobic Sludge Digestion," Jour. Water Poll. Control
Fed., 35, No. 1, p. 11-42 (1963).
103
-------
27. Dague, R. R., "Application of Digestion Theory to Digester Control,"
Jour. Water Poll. Control Fed., 4_0, No. 12, p. 2021-2032 (1968).
28. Pohland, F. G., General Review of Literature on Anaerobic Sewage Sludge
Digestion,ir Purdue University, Engineering Extension Series No. 110,
1962, 44 p.
29. Pohland, F. G., and K. H. Mancy, "Use of pH and pE Measurements during
Methane Biosynthesis," Biotechnology and Bioengineering, XI, p. 683-
699 (1969).
30. Heukelekian, H., and B. Heinemann, "Studies on the Methane Producing
Bacteria. II. Enumeration in Digesting Sewage Solids," Sewage Works
Jour., 11, No. 3, P. 436-444 (1939).
31. McCarty, P. L., "Anaerobic Wastes Treatment Fundamentals, Part II.
Environmental Requirements and Control," Public Works, 10, p. 123-126
(1964).
32. Mylorie, R. L., and R. E. Hungate, "Experiments on the Methane Bacteria
in Sludge," Canadian Jour. Microbiology, 1, No. 1, p. 55-64 (1954).
33. McCarty, P. L., "Anaerobic Waste Treatment Fundamentals, Part III.
Toxic Materials and their Control," Public Works, JL1, p. 91-94
3k. Kugelman, I. J., and K. K. Chin, "Toxicity, Synergism and Antagonism
in Anaerobic Waste Treatment Processes," In: Anaerobic Biological
Treatment Processes, F. G. Pohland (ed.), American Chemical Society,
Washington, D. C., Advances in Chemistry Series 105, 1971, P- 55-90-
35. Sawyer, C. N., F. S. Howard, and R. Pershe, "Scientific Basis for Lining
of Digesters," Sewage and Industrial Wastes, 2_6, No. 8, p. 935-944 (1954),
36. Culham, W. B., and R. A. McHugh, "Leachate from Landfills may be New
Pollutant," Jour. Envlr. Health, 31> No. 6,p. 551-556 (19^9).
37. Cartwright, L. V., and Sherman, F. B., "Evaluating Sanitary Landfill
Sites in Illinois," Illinois Geol. Survey, Envir. Geology Notes, 27,
15 p. (1969).
38. "Development of Construction and Use Criteria for Sanitary Landfills,"
Interim Report, U. S. Public Health Service, Grant D01-U1-00046, 1969.
39. Hughes, G. W., R. A. Landon, and R. N. Farvolden, "Hydrogeology of Solid
Waste Disposal Sites in Northeastern Illinois," Final Report, U. S.
Environmental Protection Agency, Publication SW-120, Washington, D. C.,
1971, 154 p.
40. APWA, AWWA, APHA, "Standard Methods for the Examination of Water and
Wastewater,"' 13th Edition, New York, Amer. Public Health Association,
1971, 874 p.
104
-------
Ul. Boyle, W. C., and R. K. Ham, "Treatability of Leachate from Sanitary
Landfills, " Proceedings of the 27th Industrial Waste Conference,
Purdue University, Engineering Extension Series No. 141, Part 2, 1972,
p. 687-7C4.
k2. Ho, S., ¥. C. Boyle, and R. K. Ham, "Chemical Treatment of Leachates from
Sanitary Landfills," Jour. Water Pollution Control Fed., k6, No. 7,
p. 1776-1791 (197*0.
ij-3. Thornton, R. J., and Blanc, F. C., "Leachate Treatment by Coagulation
and Precipitation," Jour. Environmental Engineering Piv., Proc. Amer.
Soc. Civil Engineers, 99 > No. EE4, p. 535-5^ (1973).
kk. Fernandez, R. W., "The Treatability of Leachate from Shredded Refuse
Columns," M. S. Report, University of Florida, 1972, 96 p.
l<-5. Karr, P. R., "Treatment of Leachate from Sanitary Landfills," Special
Research Report, Georgia Inst. of Technology, 1972, 73 P.
k6. Mingledorff, F. C., "Preliminary Investigations on the Chemical Treatment
of Leachate from Sanitary Landfills," Special Research Report, Georgia
Inst. of Technology, 1973> ^ P.
105
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-75-OU3
2.
4. TITLE AND SUBTITLE
SANITARY LANDFILL STABILIZATION WITH LEACHATE
RECYCLE AND RESIDUAL TREATMENT
7. AUTHOR(S)
Frederick G. Pohland
9. PERFORMING ORGANIZATION NAME AND ADDRESS
School of Civil Engineering
Georgia Institute of Technology
Atlanta, Georgia 30332
12. SPONSORING AGENCY NAME AND ADC
Municipal Environmental F
Office of Research and De
U.S. Environmental Protec
Cincinnati, Ohio 145268
15. SUPPLEMENTARY NOTES
Project Officer - Dirk R.
)RESS
tesearch Laboratory
velopment
tion Agency
3. RECIPIENT'S ACCESSION-NO.
5. REPORT DATE
October 1975
(issuing Date)
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
1DB061+; ROAP 21BFQ; Task 014
11. KOBCRBaJXr/GRANT NO.
R-801397
13. TYPE OF REPORT AND PERIOD COVERED
Final, 1970-197^
14. SPONSORING AGENCY CODE
Brunner, 513/68U-M87
16. ABSTRACT
Results of an experimental system for study of landfill disposal of approximately
0.3 m3 (10 ft3) of domestic refuse are provided. The study evaluated not only
traditional landfill decomposition as represented by single pass of water originating
from rainfall but also recirculation of the collected leachate. Sewage sludge addi-
tion to the solid waste and pH control of the recirculated leachate were also evalu-
ated. Biological and physical -chemical methods for treatment of leachates, especially
those derived from the stabilized solid waste undergoing leachate recirculation were
also evaluated.
Analysis of about 3 years of data indicated that leachate recirculation was very
beneficial in accelerating the removal of at least the readily available organics
from the refuse and leachate. This rate of removal, accomplished over a period of
months for the recirculated units as compared to the traditional, single pass unit,
was further enhanced by the initial addition of sewage sludge and by pH control.
The leachate treatment studies indicated that either aerobic or anaerobic biological
processes successfully remove leachate organics and that the effluent residuals could
be polished by activated carbon adsorption and/or ion exchange either separately or
in combination.
17.
a. DESCRIPTORS
KEY WORDS AND DOCUMENT ANALYSIS
b.lDENTIFIERS/OPEN ENDED TERMS
Waste disposal, *Refuse disposal, *Sludge Accelerated sanitary
disposal, *pH control, Digestion (decom- landfill stabilization,
position), Gases, Leaching, Waste treat- Leachate recirculation,
ment, *Activated carbon treatment, *Ion Leachate treatment,
exchanging, *Aerobic processes, *Anaerobic Anaerobic filter
processes
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report)
UNCLASSIFIED
2O. SECURITY CLASS (This page)
UNCLASSIFIED
c. COS AT I Field/Group
13B
21. NO. OF PAGES
116
22. PRICE
EPA Form 222O-1 (9-73)
106
U. S. GOVHIWENT PRIHTIHG OFFICE 1975-657-695/5332 Region No. 5-11
------- |