&EPA
United States
Environmental Protection
Municipal Environmental Research EPA-600/2-79-038
Laboratory July 1979
Cincinnati OH 45268 >» t
Research and Development
Liner Materials
Exposed to
Municipal Solid
Waste Leachate
Third Interim Report
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental ^
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology 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 Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-79-038
July 1979
LINER MATERIALS EXPOSED TO MUNICIPAL SOLID WASTE LEACHATE
Third Interim Report
by
Henry E. Haxo, Jr.
Robert S. Haxo
Thomas F. Kellogg
Matrecon, Inc.
Oakland, California 94623
Contract No. 68-03-2134
Project Officer
Robert Landreth
Solid and Hazardous Waste Research Division
Municipal Environmental Research Laboratory
Cincinnati, Ohio 45268
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
U.S. Environmental Protection Agency
Region V, Library
230 South Dearborn Street
Chicago, Illinois 60604
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DISCLAIMER
This report has been reviewed by the Municipal Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publica-
tion. Approval does not signify that the contents necessarily reflect the
views and policies of the U.S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or rec-
ommendation for use.
U,S. Environmental Protection Agency
11
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FOREWORD
The Environmental Protection Agency was created because of increasing
public and government concern about the dangers of pollution to the health
and welfare of the American people. Noxious air, foul water, and spoiled
land are tragic testimony to the deterioration of our natural environment.
The complexity of that environment and the interplay between its components
require a concentrated and integrated attack on the problem.
Research and development is that necessary first step in problem solu-
tion and it involves defining the problem, measuring its impact, and search-
ing for solutions. The Municipal Environmental Research Laboratory develops
new and improved technology and systems for the prevention, treatment, and
management of wastewater and solid and hazardous waste pollutant discharges
from municipal and community sources, for the preservation and treatment of
public drinking water supplies, and to minimize the adverse economic, social,
health, and aesthetic effects of pollution. This publication is one of the
products of that research; a most vital communications link between the re-
searcher and the user community.
Although the information contained herein is preliminary, it will pro-
vide a guide and insight to the effects that happen after limited exposure.
This information and data could be useful for design purposes if not taken
out of context.
Francis T. Mayo, Director
Municipal Environmental Research
Laboratory
111
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ABSTRACT
This report is the third interim report of a project that aims to assess
the effects upon various liner materials of extended contact with leachate
from simulated sanitary landfills. In this part of the study, the primary
exposure tests of liner specimens at the bottom of simulated landfills were
supplemented by immersion of 28 different polymeric materials in sanitary
landfill leachate. Immersed membranes were tested for changes in physical
properties, permeability, and water absorption. The polymeric materials
tested included butyl rubber, chlorinated polyethylene, chlorosulfonated
polyethylene, elasticized polyolefin, ethylene propylene rubber, neoprene,
polybutylene, polyester elastomer, low-density polyethylene, plasticized
polyvinyl chloride, and polyvinyl chloride plus pitch.
The results of the immersion tests generally confirm the earlier results
for membrane liner materials exposed for one year in simulated landfills.
Specimens of chlorinated polyethylene, chlorosulfonated polyethylene,
ethylene propylene rubber, and neoprene liners showed the greatest swell and
loss of properties, although specimens of some ethylene propylene rubber and
neoprene liners showed low swelling and little loss of properties.
Also reported are results of the water vapor permeability testing of
28 membrane liners, the water absorption of a series of membranes at room
temperature and at 70°C, and the retrieval and testing of samples of a 6-
year old membrane liner from a demonstration landfill. The monitoring of the
simulated landfills during 180 months of operation is described and the
analyses of the leachates produced during the period of operation are
summarized.
A simple bag test for assessing permeability and physical properties of
membrane liners for landfills is described and test results are presented.
This report was submitted in partial fulfillment of Contract 68-03-2134
by Matrecon, Inc., under the sponsorship of The U. S. Environmental Protec-
tion Agency. It covers work performed during the period January 1, 1976
to May 31, 1978.
IV
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CONTENTS
Foreword
Abstract
List of Figures .......................................... _ _ f v^
List of Tables [[[ vi^
List of Abbreviations and Metric Conversion Table ..................... viii
Acknowledgements . . .................... j
*******"*"***"«» JLj£
1 . Introduction ......................................... ^
2 . Summary .............. ......... , .................. *
3 . Future Work ........................................... g
4 . Experimental Work ..... . ...................................... 8
Immersion of Membrane Liners in Leachate ................. 8
Water Vapor Permeability of Polymeric Membrane Lining
Materials ........................................... ±Q
Bag Test for Assessing Membrane Liner Materials .......... 24
Water Absorption of Membrane Liner Materials ............. 31
Monitoring the Leachate Generators ....................... 34
Recovery and Testing of Samples of a Polyvinyl Chloride
Liner from a Demonstration Landfill ................... 43
References ................. . .................... 4fi
Appendices [[[ ' ' 47
A. Properties of Unexposed Polymeric Membranes in Project ...... ... 47
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LIST OF FIGURES
Number Page
1. Individual polyethylene immersion tank ............ 10
2. Immersion system set up with gravity feed of leachates .... 11
3. Immersion system set up with pump and gas relief valves. ... 12
4. Leachate pH during the immersion test ............. I5
5. E96 water vapor permeability cup and auxiliary equipment ... 19
6. Constant-air-velocity cabinet for holding E96 permeability cups 22
7. Schematic of osmosis bag assembly ............... 26
8. Osmosis bag and auxiliary equipment for monitoring ...... 27
9. Leachate collection bag with water seal and vent ....... 36
10. Average solids content of leachate produced in generators. . . 37
11. Average pH of leachate produced in the generators ....... 38
12. Average total volatile acids of leachate produced in the
->Q
generators ......................... J:y
13. Average chemical oxygen demand of leachate produced in the
40
generators .........................
14. Average refuse consolidation in the 12 generators.
41
VI
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LIST OF TABLES
Number
1 Analysis of Leachate used in the Immersion System 14
2 Summary of Effects of Immersion of Polymeric Membrane Liners in
Leachate for 8 months 17
3 Effects of Test Conditions on Water Vapor Permeability of Polymeric
Membrane Liners 20
4 Water Vapor Permeability of Polymeric Membrane Liners 23
5 Effect of Test Time on Water Vapor Permeability 24
6 Characteristics of Leachate in Bags 25
7 Tests of Membrane Liner Bags Filled with Leachate 29
8 Tests of Bags Containing Leachate 28
9 Tests of Membrane Liner Bags Filled with 5% NaCl Solution 30
10 Test of Bags Containing 5% Salt Solution 31
11 Water Absorption of Selected Membrane Liner Materials 33
12 Order of Increased Swelling in Water 32
13 Comparison of the Swelling of Membrane Lining Materials 34
14 Cumulative Collection of Leachate Below Liners 42
15 Analyses of Polyvinyl Chloride Liner from Demonstration Landfill . 44
16 Properties of Polyvinyl Chloride Liner from Demonstration Landfill. 45
VII
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LIST OF ABBREVIATIONS
cm centimetres
COD chemical oxygen demand
h hour
Hg mercury
ipm inches per minute
MPa megapascals
ymho micro-mho
ml millilitres
mm millimetres
pH hydrogen ion concentration
ppi pounds per inch
ppm parts per million
psi pounds per square inch
TVA total volatile acids
METRIC CONVERSION TABLE
FACTORS FOR CONVERTING DATA IN U. S. CUSTOMARY UNITS TO SI METRIC UNITS
Inches to centimetres (cm) x 2.54
Feet to metres x 0.3048 _3
Mils to centimetres (cm) x 2.54 x 10_2
Mils to millimetres (mm) x 2.54 x 10 _3
Pounds per square inch (psi) to megapascals (MPa) x 6.895 x 10_1
Pounds per inch (ppi) to kilo Newtons per metre (kN/m) x 1.751 x 10
Pound (force) to Newtons x 4.448
Some U. S. Customary units are used in this report as they are commercially
used in the United States in the solid wastes industry as well as the liner
production and installation industries.
viii
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ACKNOWLEDGEMENTS
The authors wish to thank Robert E. Landreth for his support and guid-
ance in this project. They also wish to acknowledge the guidance of Dr.
Clarence Golueke and Stephen Klein of the Sanitary Engineering Research
Laboratory, University of California, Berkeley, California, who were
responsible for the analyses and characterization of the wastes.
The following companies contributed to this project by supplying
samples, information, and technical assistance:
Burke Industries, Inc.
Carlisle Tire and Rubber Company
Cooley, Inc.
Dow Chemical Company
E. I. du Pont de Nemours and Company
Exxon Chemical Company
Firestone Tire and Rubber Company
Gaco Western, Inc.
B. F. Goodrich Company
Goodyear Tire and Rubber Company
Pantasote Company
Phillips Petroleum Company
Plymouth Rubber Company
Polysar Corporation
Quarry Products, Inc.
Ransome Company
Reeves Bros., Inc.
Ruberoid Building Products, Ltd.
Staff Industries
Union Carbide Company
Watersaver Company
Witco Chemical Corporation
We also gratefully acknowledge the cooperation of The Asphalt Institute
and The Portland Cement Association.
IX
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SECTION I
INTRODUCTION
The lining of sanitary landfills with impervious materials has been
found to be a feasible method of intercepting and controlling leachate that
may be generated in a landfill and preventing it from entering and polluting
surface and ground waters. A wide variety of materials were potentially
useful for lining sanitary landfills but this application and information
regarding the effects of leachate contact were almost nonexistent when this
study was initiated. A technology that had been developed to impound and
control water in canals, ponds, etc., appeared to be applicable to the
lining of sanitary landfills, but the effects of prolonged contact.of liner
materials with leachate were not known. The development of this type of
information was needed to insure the choice of adequate materials for lining
sanitary landfills. This study was undertaken to develop such information
in terms that could be readily understood by engineers, designers, and users.
OBJECTIVES
The primary objectives of the project as a whole are as follows:
1. To determine the effects of exposure to leachate from compacted,
municipal refuse on the physical properties of 12 selected liner
materials (excluding soils and clays) that were believed to be
potentially useful for the lining of sanitary landfills.
2. To determine the durability of these liner materials and to estimate
their effective lives when exposed to leachate for prolonged periods
under conditions comparable to those encountered in a sanitary land-
fill.
3. To develop accelerated testing procedures for evaluating new
materials that may have potential application to lining landfills.
4. To analyze the costs of sanitary landfill liner materials,
including installation costs and the benefits of greater durability.
BACKGROUND
The primary effort in this project has been to assess the effects of
landfill leachate on a wide range of potential liner materials (except soils
and clays) under conditions that simulate real-life exposure. In taking this
approach, which would develop information that would be directly translatable
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into use in field application, we constructed 24 simulated landfills, each
containing about one cubic yard of shredded municipal refuse. Specimens,
two ft in diameter, of 12 different lining materials, six polymeric mem-
branes and six admixes, were sealed in the bases (1-4). Leachate was pro-
duced in each generator by saturating the refuse and adding one in. of tap
water on a biweekly basis to equal 26 in. of water per year. Leachate was
allowed to pond on the liner specimens to a depth of one ft to supply an
hydraulic head and thus a driving force for the leachate to seep through the
liner specimen.
The exposure tests of the primary membrane liners were supplemented by
simultaneously exposing two sets of small specimens of 42 polymeric membrane
materials. These were buried in the sand above the primary liners.
The permeabilities of the primary liners are being assessed by measuring
the amount of leachate that seeps through the liners. The effects of
leachate upon the properties of liners are determined by recovering and
testing the liner specimens at two time intervals, initially planned for
12 and 14 months, but now planned for 12 and 55 months.
In November 1975, after a year of exposure, the first of the two sets
of samples was recovered, and properties of the leachate exposed materials
were measured. Results were presented in the Second Interim Report (2).
One year of exposure to landfill leachate had only relatively minor effects
upon all the liner materials under test. All materials appeared to have
maintained their original permeabilities. The admix materials became some-
what more impermeable.
Losses were measured in the compressive strength of the admix materials
and in the physical properties of some of the polymeric membranes. Most
membranes swelled; the chlorinated polyethylene and the chlorosulfonated
polyethylene were affected the most, and the polyolefins, polyethylene,
polypropylene, and polybutylene, the least.
The limited effects of the one year of exposure on the liner materials,
even in leachate that was considered to be relatively concentrated, made
long-term extrapolations to liner service life very tenuous. Consequently,
the exposure period was extended and the dismantling and testing of the
liner materials was postponed, first to June 1978, and later to July 1979.
In addition, the scope of the project was expanded to include immersion
studies, analyses of liner materials, additional permeability studies, and
efforts to develop simpler testing procedures for evaluating liner materials
for sanitary landfills.
Progress in this project is being presented in a series of interim
reports. The First Interim Report (1) describes the overall technical
approach, the construction of the leachate generators, the selection of
liner materials, the loading of the cells with ground refuse, and the
bringing of the cells to field capacity. In that report, various liner
materials, are discussed, and the bases for selecting the 12 primary materials
are presented. The original properties of unexposed liner materials were
determined so that the effects of the various exposures could be measured
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from these values. Cost data for the various materials used to line ponds,
lagoons, pits, etc., are also examined.
The Second Interim Report (2) presents the results of exposing liner
materials to leachate for one year. The monitoring of the generators is
described, and the analyses of leachate generated over the one-year period
are reported. Also described are the overall operation of the leachate
generators and the performance of the materials employed in fabricating the
apparatus used in this project. Permeability of the various materials to
water and leachate is discussed. The report also includes Appendixes of
test data taken from the First Interim Report (1).
This report, the Third Interim Report, covers the period January 1976
through May 1978, and concentrates on the membrane liner materials.
Discussed are the testing of liner materials by immersion in leachate;
water vapor permeability, leachate, and water absorption of polymeric
membranes; permeability of thermoplastic, heat-sealable membranes to
leachate by osmosis; the continued monitoring of the leachate generators,
and the recovery and testing of a sample of polyvinyl chloride liner taken
from a demonstration landfill. The design, construction, and operation of
the immersion system are also described.
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SECTION 2
SUMMARY
IMMERSION TESTS
Three sets of 28 different polymeric membrane liner specimens were
immersed in a series of tanks containing a blend of leachates produced in
the 12 generators. This system was designed to maintain anaerobic condi-
tions and to allow the leachate to flow slowly through the tanks. After
8 months of immersion, one set of the 28 lining specimens was removed and
tested.
The eight months of immersion in leachate appears to be approximately
equivalent to one year of one-sided exposure of the primary specimens of
the same materials in the bases of the generators. This immersion condition
duplicated the effects on the buried specimens of the same liners placed in
the sand. In the case of the other lining materials which are not being
exposed in the generators, the effects were not large. The liners based
upon chlorinated polyethylene, chlorosulfonated polyethylene, and neoprene
tended to swell and soften more than the other lining materials. On the
other hand, the polyolefins, such as polyethylene, polybutylene, elasticized
polyolefin, and polyester elastomer, all of which are partially crystalline,
swelled and softened the least. The polyvinyl chloride membranes approxi-
mated the latter materials in swelling and changes of properties.
WATER VAPOR PERMEABILITY
Permeability testing of the various membrane liner materials has been
continued, using several test methods. Results of water vapor permeability,
by ASTM E-96, Method BW (5), are reported for 27 different liner materials,
including butyl rubber, chlorinated polyethylene, chlorosulfonated poly-
ethylene, elasticized polyolefin, ethylene propylene rubber, neoprene,
polyester, and polyvinyl chloride. As a group, the polyvinyl chloride liner
materials have the highest permeability to water vapor and the butyl rubber
and elasticized polyolefin the lowest. Permeability appears to increase
with test time, probably because of swelling of the membranes by water.
OSMOTIC BAG TEST
A laboratory test method now being developed appears feasible for
assessing membrane materials for lining sanitary landfills and the contain-
ment of hazardous wastes. In this test, leachate or other waste fluid is
sealed in a small bag fabricated of the material under test. The bag is
then placed in a somewhat larger bag containing deionized water. The
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permeability of the membrane is assessed by measuring weight increase of the
inner bag and pH and conductivity of the deionized water. After the perme-
ability test is completed, the physical properties of the bag material can
be measured to determine the effects of exposure to the leachate. Data are
presented for bags made of six different polymeric membranes in which
leachate and 5% salt solution were sealed. During immersion in the deion-
ized water, the bags increased in weight and the deionized water changed in
pH and conductivity, depending on the membrane.
WATER ABSORPTION TESTS OF SELECTED MEMBRANE LINERS
Two series of water swelling tests, run for 100 weeks at room temper-
ature and at 70°C, indicate that membrane liners of neoprene, chlorosulfon-
ated polyethylene, and chlorinated polyethylene continually swell in water,
whereas the polyethylene, polybutylene, polyester, and elasticized poly-
olefin reach a plateau in the swell, as does polyvinyl chloride. At least
one of the polyvinyl chloride liners tended to harden on long-term exposure,
indicating loss of plasticizer.
MONITORING OF THE LEACHATE GENERATORS
The 12 simulated landfills in which 12 different liner materials are
being exposed to leachate continue to be operated. No leachate has been
collected below the liners of seven of these generators after 43 months of
operation. Two of the generators with butyl rubber and polyethylene
membrane liners appear to have failed at the epoxy resin seals between the
liners and the bases of the generators. Two admix liners, soil asphalt and
soil cement, have allowed minor amounts of leachate to seep into the bases.
The current schedule calls for the operation of the 12 generators to be
continued until July 1979, when they will be disassembled and the liners
will be retrieved and tested.
The leachate that is being produced in the 12 generators is gradually
becoming more dilute in solids content, chemical oxygen demand, and
volatile acids. Also, the average pH has now risen from approximately 5 to
6.5, with leachate from several generators over 7.0.
The refuse in the cells continues to consolidate linearly with time.
After 43 months, the average consolidation of shredded refuse in the 12
remaining generators is 16%.
RECOVERY AND TESTING OF MEMBRANE LINER FROM A LANDFILL
Samples of a polyvinyl chloride liner were retrieved from a demon-
stration landfill and tested. This liner had good properties and probably
changed little during the six-year exposure period. Because of an
impermeable clay cover on the membrane, leachate probably did not directly
contact the liner; furthermore, the leachate appeared to be quite dilute.
There were no data available on the properties of the liner before exposure
with which to make a comparison.
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SECTION 3
FUTURE WORK
The period covered by this project has been extended through November
1979, during which time the following tasks will be performed:
Exposure of the primary liners in the bases of the~leachate
generators will be continued through June 1979, when they will have
been exposed for 56 months. The exposure of the small supplemental
specimens buried in the sand above the primary liners will also be
continued.
The immersion and osmosis bag tests now underway will be continued.
- The second set of 28 specimens will be recovered in June 1978 and
tested after 19 months of immersion in leachate and the third and
final set will be removed and tested in June 1979 after 30 months of
immersion in leachate. At the end of the project the membrane
osmosis bags will be cut and the membranes tested.
The small specimens buried in the sand above the primary liners in
the two leachate generators containing the asphaltic membranes will
be recovered and tested in June 1978 to assess the effects of 43
months of exposure to leachate. These two primary liners will be
inspected and one will be sampled and a repair made. New small
membrane samples will be placed in the sand and the generators will
be returned to operation for the remainder of the project.
- Permeability studies will be expanded as follows:
a. Additional bags will be prepared to assess the permeability of
membrane liner materials to water and to dissolved constituents
of the leachate.
b. A newly-designed top-pressure permeameter will be used to
determine the permeability of membrane liners to leachate.
c. Additional tests will be made of water vapor permeability using
ASTM E-96, Method BW.
d. The permeability of membrane liners to gases, such as methane,
carbon dioxide, and air, will be determined.
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The various methods of joining dissimiliar lining materials will be
investigated and, if necessary, experimental work will be performed
to develop adequate methods for limited combinations.
The analysis of membrane liners will be completed for possible use
in specifications.
The specifications now being followed by manufacturers, suppliers,
and installers of various liner materials will be reviewed.
An investigation of soil-membrane liner composites will be carried
out to determine the effect of a soil cover on the rate of deteri-
oration of the membrane liner.
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SECTION 4
EXPERIMENTAL WORK
IMMERSION OF MEMBRANE LINERS IN LEACHATE
Assessing liner materials for lining sanitary landfills by exposing to
leachate at the bottom of simulated landfills, such as is being done in this
project, is time-consuming and expensive. Simpler methods are needed to
evaluate a liner material for this application. The results obtained in
this project should form a basis for the development of simpler procedures
which will correlate with the results obtained and with actual landfill
experience.
An obvious simplification of the simulated landfill method is to im-
merse specimens of various liner materials in the leachate from municipal
refuse and determine the changes in properties during the exposure. The
availability of leachate from the simultated landfills presents the oppor-
tunity for obtaining a direct correlation between these two procedures for
use in developing a laboratory evaluation test. The same materials can be
tested by the two methods in essentially the same leachate.
Membrane liners are amenable to immersion testing but admix materials
pose many experimental problems in such types of tests. The study which
was undertaken of the effects of immersion in leachate was, therefore,
restricted to membrane liners.
Our basic plan was to immerse liner specimens of sufficient size to be
able to obtain data on volume arid area swell and on the same physical
properties as were measured on the primary liners. The leachate from the
generators would be used and allowed to flow slowly past the specimens.
The liner materials selected would include some of the materials
being exposed in the simulated landfills as well as new materials which
have subsequently become available either commercially or on a developmental
basis. In order to obtain sufficient data with which to make projections
of service life, it was planned to immerse three sets of liner specimens
and to withdraw them at three time intervals. Originally it was planned to
immerse the specimens for six months, 12 months and 18 months, but the times
were later changed to eight months, 19 months and 30 months.
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Design and Construction of the Immersion System
We originally planned to attach small cells or bags containing the
liner specimens directly to the individual leachate generators and allow
the leachate to flow by the specimens as it was continuously being
collected. Such a design would maintain the anaerobic condition that
existed in the generator where the primary liners were being exposed.
However, the leachates being produced were varying in composition from one
generator to another which would make comparison between liners difficult.
Furthermore, the number of containers would be large and monitoring of
the 12 generators with the attached containers posed a variety of problems
and additional effort.
This design was replaced with one in which blended leachate from the
12 generators slowly flowed through a series of polyethylene tanks in which
the membrane specimens could be hung. We felt this arrangement would be
acceptable because only small changes in composition of the leachate were
observed when it was stored in polyethylene containers at room temperature
over a period of one month. Furthermore, this design allowed easy exposure
of more specimens, exposures of all specimens to the same leachate, and
required considerably less time to construct and monitor.
After considering a wide variety of containers for use as immersion
cells, we selected heavy-duty high-density polyethylene tanks (Nalgene),
14 x 10 x 10 in. in dimensions, each with a 6-gal capacity. These tanks,
which were placed on a 3.5 ft wooden platform, are of heavy-gauge con-
struction with flat lids from which the specimens were hung on stainless
steel hooks. Inlets and outlets were installed, and the lids with the
specimens were welded to the tanks (Figure 1). The flow of the leachate
through the tanks was by gravity feed from a drum containing leachate
placed above the tanks as shown in Figure 2. Problems were encountered
with this arrangement due to plugging of the system by precipitation of
solids in the leachate.
A Masterflex pump was, therefore, installed that delivered leachate
at the rate of 14 ml per minute through the tanks, recirculating the
supply of leachate in about 12 days (Figure 3).
Exposure Specimens
Twenty-eight different membranes of 11 different polymeric materials
were selected for immersion testing:
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COVER DETAIL
SPECIMENS ATTACH
TO HOOKS
CROSS SECTION
LEACHATE IN -^ ^- LEACHATE OUT
LEACHATE IN
LEACHATE OUT
14 SPECIMENS
NOTE:
PLASTIC WELD SEALS
COVER TO CONTAINER
POLYETHYLENE TANK
Figure 1. Individual polyethylene immersion tank, showing method of
holding specimens and the inlet and outlet for the leachatfe.
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Figure 2. Immersion system set up with gravity feed of leachates through
the tanks. Leachate generators are in the rear.
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DO
Figure 3. Immersion system set up with pump and gas relief valves on
individual tanks. The pump is in the center of the upper
shelf; leachate generators are in the rear.
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Number of different
Type of Material liners immersed
Butyl rubber 1
Chlorinated polyethylene (CPE) 3
Chlorosulfonated polyethylene (CSPE) .... 3
Elasticized polyolefin 1
Ethylene propylene rubber 5
Neoprene 4
Polybutylene (PB) 1
Polyester elastomer 1
Polyethylene (PE) 1
Polyvinyl chloride (PVC) 7
PVC and pitch 1
Total 28
Three specimens of each membrane were immersed in the leachate in sets of
the 28 so that they could be removed from the system after three exposure
periods.
The 8 x 10 in. size of the test specimens was sufficient to make all of
the tests required. The specimens were hung vertically 0.92 in. apart in
the tanks (Figure 1).
The tests which were performed on the lining materials before exposure
and at three subsequent intervals are:
Weight, before and after exposure.
Dimensions, before and after exposure.
Tensile strength, in machine and transverse direction, ASTM D412.
Hardness, ASTM D2240.
Tear strength in machine and in transverse direction,
ASTM D264, Die C.
Puncture resistance, FTM 101B, Method 2065.
Volatiles at 105°C, ASTM D297.
Specific gravity, ASTM D297.
The physical properties of the unexposed lining materials that were
immersed are presented in Appendix A.
Operation of Immersion System
Approximately 48 gallons of leachate obtained by blending the output
of the 12 generators, was introduced into the system every 4 weeks and a
similar amount of the used leachate was drawn off. The new leachate was
the accumulation of the two previous collections of 24 gallons each from
the generators. Samples of both the new and used leachate were tested at
each addition for: pn, chemical oxygen demand (COD), total solids (TS),
total volatile solids (TVS), and total volatile acids (TVA).
13
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The differences in the composition of the leachate added and of that
removed were small, indicating the air-tight, anaerobic character of the
system. During the initial operation of the system, the analytical results
(Table 1) were close to the calculated averages of the leachates from the
generators (see below, "Monitoring the Leachate Generators"). In later
months, however, differences developed between the two that may have been
caused by biological contamination of the blended leachate. The pH of the
leachate from the generators (Figure 4) is increasing at a regular rate
(see below, "Monitoring the Leachate Generators"); however, the pH of the
blended leachates in the system became substantially higher in October-
November 1977 and has remained high.
TABLE 1. ANALYSIS OF LEACHATE USED IN THE IMMERSION SYSTEMa
Leachate added Leachate removed
Property to system from system
PH
Chemical oxygen demand, g/1
Total volatile acids, g/1
Total solids, %
Total volatile solids, %
5.27
32.6
11.3
1.70
0.94
5.27
29.0
11.3
1.80
1.00
Samples were taken on January 31, 1977.
Some gas was generated in the tanks, which necessitated the addition of
relief valves to prevent pressure buildup. During the course of the
operation there were two leaks in the welds that required repairs.
Results of Exposure to Leachate
After eight months of immersion, two tanks containing one set of test
specimens were removed from the system and the exposed specimens were
recovered and tested to assess the effects of exposure to leachate.
Retrieval consisted of bypassing the cells to be removed, disconnecting
them, flushing them with water, and then cutting open the cells. Exposed
liner samples were stored in polyethylene bags to retain moisture until
testing could be completed. The results of analyses and measurements of
physical properties of the exposed specimens are presented in Appendix B.
14
-------
Ul
7.5
7.0
" 6.5
6.0
5.5
UJ
fe
i
5.0
4.5
O pH OF LEACHATE ADDED TO SYSTEM
pH OF LEACHAT REMOVED FROM SYSTEM
1977
r
i
i
FIRST SET OF IMMERSION SAMPLES REMOVED
-1978-
100 20) 300
ELAPSED TIME, DAYS
Figure 4. Leachate pH during the Jjwiersion test.
400
500
-------
Table 2, based upon selected data from Appendixes A and B, summarizes
the effects of eight months of immersion of the 28 liner materials in
leachate, compares the 11 different types of material, and shows the
ranges of leachate absorption and the retention of physical properties for
each type of material.
The materials tested fell into three groups with regard to swelling or
leachate absorption during the eight months:
1. Those with the greatest leachate absorption, which included the
chlorosulfonated polyethylene and the chlorinated polyethylene
liners (13% to 19% and 8% to 10%, respectively). Neoprene and
ethylene propylene rubber ranged from low to high absorption (1%
to 19% and 1% to 13.5%, respectively).
2. Those with low leachate absorption, which included the polyolefins,
plasticized polyolefin, and polybutylene (all with 0.1% absorption),
and polyethylene (with 0.6% absorption).
3. Those with relatively low leachate absorption, which included
polyvinyl chloride (1% to 3%), polyester (2%), and butyl rubber
(1% to 2%).
The membrane liner of polyvinyl chloride plus pitch swelled 6%.
Changes in physical properties generally followed swelling. Those
specimens that swelled little changed relatively little in physical
properties. The materials that exhibited significant drops in tensile
strength during the exposure period were neoprene, chlorinated polyethylene,
and chlorosulfonated polyethylene. They were the materials that swelled
the most. The polyolefins showed little loss, as did the polyvinyl chloride
liners. In elongation at break, there was a similar effect, except that one
of the ethylene propylene rubber materials exhibited a significant loss when
tested in the transverse direction. This material appeared to have cured
or crystallized during exposure, resulting in a substantial increase in
modulus.
A general decrease in hardness and modulus of the liners occurred
during exposure, but there were some increases, i.e., the ethylene
propylene rubber discussed above and some specimens of chlorinated poly-
ethylene and chlorosulfonated polyethylene.
Overall, the polyolefins and polyvinyl chloride materials changed the
least during the immersion period. As groups of materials, the polyvinyl
chloride membranes varied the least during this time period and neoprene
and ethylene propylene rubber varied the most.
16
-------
TABLE 2.
SUMMARY OF THE EFFECTS OF IMMERSION OF POLYMERIC MEMBRANE LINERS IN LEACHATE FOR 8 MONTHS
Polymer
Butyl rubber
Chlorinated
polyethylene
Chlorosulfonated
polyethylene
Elasticized polyolefin
Ethylene propylene
rubber
Neoprene
Polybutylene
Polyester elastomer
Polyethylene
Polyvinyl chloride
Polyvinyl chloride
+ pitch
a
No. of
liners
in test
1
3
3
1
5
4
1
1
1
7
1
Absorption
of leachate,
%
1-2
8-10
13-19
0.1
1-13.5
1-19
0.1
2.0
0.6
1-3
6.0
% Original value
Tensile strength
90-97
80-115
82-124
86-94
90-91
69-100a
96-99
99-115
110-180
91-110
92
for unexposed
Elongation
104-106
64-135
97-107
91-92
76-138
82-103a
96-97
101-108
96-181
98-129
109-133
membrane
S-200
85-86
84-123
47-113
102-106
98-220
79-102a
99-103
95-110
100-116
76-102
93-108b
Change in
hardness ,
points
0
-5 to -1
-20 to -4
0
-1 to +2
-11 to +5
-3
-4
7
-2 to +1
-2
^ on fabric-reinforced neoprene liner #42 were not included.
S-100 - unexposed specimen broke at 150% elongation.
-------
As indicated above, there were considerable variations among the speci-
mens of a given polymer type, as shown in Table 2 and Appendix B. These
variations within a single polymer group point out the importance of other
factors in addition to the polymer that determine the properties of a given
liner composition. For example, swelling would be greatly affected by
crosslinking, percent of crystallinity, and the type and amount of fillers
used. Minor amounts of other constituents, such as soaps and occluded salts
from the preparation of the polymer can also affect swell.
Two additional sets of the same 28 polymeric liner materials remain in
the immersion tanks. These will be retrieved and tested after immersion
periods of 19 and 30 months.
WATER VAPOR PERMEABILITY OF POLYMERIC MEMBRANE LINING MATERIALS
The very low permeabilities of polymer membrane liners, compared with
those of soils and admix liner materials, have made it difficult to obtain
compatible permeability data for all these materials. Polymeric membrane
liners are nonporous. Therefore, the rate of transmission of a liquid,
such as water, depends upon its solubility in the liner and the rate of
diffusion of the molecules of the liquid through the liner. Permeameters
normally used for soils are not applicable for measuring the permeability
of membranes. Consequently, the polymeric membrane liner industry has been
using water vapor transmission as a measure of the permeability of polymeric
liners. This type of test was used to determine the permeability of the six
polymeric membranes that are being exposed as the primary liners sealed in
the bottoms of the leachate generators (2).
Test Method
The test method used in our initial measurements basically followed
ASTM E-96, "Water Vapor Transmission of Materials in Sheet Form," Method
BW (5). In this test a small water cup with a membrane specimen cover is
inverted to wet the specimen (Figure 5). The cup in the inverted position
is placed in a box having controlled temperature, humidity, and air stream,
and its loss in weight is observed as a function of time. This test is
intended for those applications in which one side is wetted under conditions
where the hydraulic head is relatively unimportant and the moisture transfer
is governed by capillary and water vapor diffusion forces. The driving
force is supplied by the difference in the vapor pressure on the two sides
of the membrane.
The conditions under which these tests were initially performed were
at variance with those specified in the ASTM Test Method E-96, leading to
high absolute values of vapor transmission. In particular, the relative
humidity on the outside of the cups was significantly less than 50% and
the air velocity was substantially higher than that called for in the
method. The relative values, however, are valid (Table 3).
18
-------
CUP IN INVERTED
POSITION
COP
TEST SPECIMEN
SEALED IN CUP
WAX FOR SEALING
LINER IN CUP
HOT PLATE FOR
HEATING WAX
MOLD FOR MAKING
RING SEAL
TEST SPECIMEN
Figure 5. E96 water vapor permeability cup and auxiliary equipment.
-------
TABLE 3. EFFECTS OF TEST CONDITIONS ON WATER VAPOR PERMEABILITY OF POLYMERIC MEMBRANE LINERS
ro
o
Rate of Water vapor Water vapor
water vapor permeance, permeability,
transmission, 10~2 g/d-m2-mmHg 10"^ g/d-m2-mmHg-cm
g/d-m2 (metric perm) (metric perm-cm)
Liner Thickness Test conditions Test conditions Test conditions
Polymer
Chlorinated
polyethylene
Chlorosulfonated
polyethylene
Polyvinyl chloride
No. mils cm ASTMa Ref.2D ASTMa Ref.2D ASTMa
12 33.3 0.085 0.264 0.610 2.10 4.60 1.76
6 37.0 0.094 0.422 0.825 4.21 6.20 3.79
17 20.0 0.051 2.97 3.69 24.4 27.7 12.0
Ref . 2"
3.70
5.70
15.0
aResults of tests made under conditions specified in ASTM E96 (data from Table 4).
bResults of tests made in low relative humidity and high air flow (data from Ref. 2).
-------
To comply with the test conditions of the ASTM method, we constructed
a small cabinet (Figure 6), to hold the cups. The cabinet has a built-in
controlled air flow and is operated in a constant-temperature and humidity
room controlled at 72 - 1°C and 50 - 2% relative humidity. The effect of
the change in test conditions on the water vapor transmission values is
shown in Table 3. The values for water vapor transmission and permeability
are significantly lower when the tests are run under the ASTM conditions,
than under the conditions existing in the previous tests, (2). This probably
reflects the higher relative humidity and lower air velocity of the ASTM
conditions. The driving force for transmission increases with increasing
difference in humidity on each side of the membrane.
Results
The water vapor permeability of 27 membrane liners, including three
previously tested, were then determined and the results are presented in
Table 4.
The polyester liner, which was the thinnest membrane in the series with
a thickness of eight mils, had the highest rate of water vapor transmission.
However, its water vapor permeability, which corrects for thickness and is
a property of the liner polymer, is in the same range as that of polyvinyl
chloride compositions, some of which are considerably more permeable. There
is a threefold variation from the lowest permeability to the highest in the
case of polyvinyl chloride liners. As a group the polyvinyl chloride liners
are the most permeable, confirming the results given in the Second Interim
Report (2). The most impermeable materials in this test series are
elasticized polyolefin or butyl rubber, both of which have less than one-
tenth of the water vapor permeability of polyvinyl chloride. There is a
considerable spread in the values for butyl rubber (Table 4) indicating
compound differences. The other liner materials are intermediate in water
vapor permeability, with a possible twofold variation among them.
Swelling of polymeric compositions, such as that anticipated for
polymeric liners exposed to leachate for long periods, generally increases
permeability. Consequently, running the permeability tests for long periods
should result in some swelling of the test specimens and higher permeability.
Table 5 presents such results for 11 liner specimens. Permeability
values obtained from the 35th to the 63rd day are compared with those
obtained before the 35th day. In all cases, values determined in the 35th
to 63rd day interval are higher than those that were determined in the
7-to 28-day interval. Furthermore, the increases tend to follow the
respective tendencies of the liner specimens to swell in water. Additional
testing of the effect of swelling on permeability is planned with pre-
swollen specimens.
21
-------
to
Figure 6. Constant-air-velocity cabinet for holding E96 permeability cups.
The cabinet is operated in a constant-humidity room having a
temperature of 73 F and a relative humidity of 50%.
-------
TABLE 4. WATER VAPOR PERMEABILITY OF POLYMERIC MEMBRANE LINERS, ASTM E-96, METHOD
Polymer
Butyl rubber
Chlorinated poly-
ethylene
Chlorosulfonated
polyethylene
Elasticized
polyolefin
E thyle ne-propyle ne
rubber
Neoprene
Polyester elastomer
Polyvinyl chloride
Liner
No.
22
57
12
38
77
86
3
6b
55
36
8
18
26
41
83
9
42
43
82
75
11
17
19
40
59
88
89
Thickness
mils
73.?
33.5
33.3
32.3
31.0
21.0
31.0
37.0
35.0
28.3
67.0
48.5
38.0
20.0
37.0
61.0
20.0
31.5
61.2
8.0
30.0
20.0
21.0
32.5
33.0
20.5
11.0
cm
0.185
0.085
0.085
0.082
0.079
0.053
0.079
0.094
0.089
0.072
0.170
0.123
0.097
0.051
0.094
0.159
0.051
0.080
0.155
0.020
0.076
0.051
0.054
0.083
0.084
0.052
0.028
Test
time,
days
49
21
28
21
21
28
32
40
42
28
28
28
28
21
28
21
42
28
63
21
28
35
42
42
21
35
35
Rate of
water vapor
tr ansmis s ion ,
g/d-m2
0.097
0.020
0 . 264
0.361
0.320
0.643
0.634
0.422
0.438
0.142
0.172
0.314
0.327
0.270
0.190
0.237
0.304
0.448
0.240
10.50
1.85
2.97
2.78
4.17
4.20
2.94
4.42
Water vapor
permeance,
10~2 g/d-m2. mmHg
(metric perm)
0.75
0.17
2.10
2.90
2.80
5.10
5.00
4.21
3.47
1.20
1.40
2.49
2.80
2.15
1.50
1.90
24.1
3.90
2.00
91.0
16.0
24.0
22.0
33.0
36.0
23.0
35.0
Water vapor
permeability,
10" g/d-m -nrnHg-cm
(metric perm-cm)
1.39
0.15
1.76
2.35
2.10
2.72
3.97
3.79
3.09
0.85
2.52
3.07
2.72
1.09
1.42
2.89
1.22
3.12
3.11
18.2
12.2
12.0
11.8
27.3
30.2
12.1
9.77
faAverage temperature, 72°F; average relative humidity, 42%.
Fabric-reinforced.
-------
TABLE 5. EFFECT OF TEST TIME ON WATER VAPOR PERMEABILITY OF MEMBRANES IN
E96-BW TEST
Polymer
Butyl rubber
Chlorinated polyethylene
Chlorosulfonated
polyethylene
Elasticized polyolefin
Ethylene propylene rubber
Neoprene
Polyester elastomer
Polyvinyl chloride
Liner
no.
57
77
6°
36
8
26
43
82
75
11
59
Permeability
metric perm- sec x 10".
7-28 daysa
0.18
2.63
2.07
1.09
2.87
3.40
3.90
1.61
1.14
15.25
38.21
35-63 days0
0.22
2.87
2.57
1.18
3.11
3.68
5.14
38.5
1.18
17.09
40.98
% Increase
22
9
24
8
8
8
32
139
3
12
7
aTemperature, 72°F; relative humidity, 54%, AP, 9.23.
Temperature, 74°F; relative humidity, 55%; AP, 9.65.
°Fabric reinforced.
BAG TEST FOR ASSESSING MEMBRANE LINER MATERIALS
As the permeability of membrane liners to water and to other leachate
components under landfill conditions is not necessarily reflected by the
water vapor permeability as determined by E-96, other methods of assessing
the permeability of liner materials are, therefore, being investigated:
1. Sealing leachate into bags fabricated from the liner membranes and
immersing these bags in deionized water. The permeation of
dissolved leachate components into the deionized water can be
observed through pH and conductivity measurements and changes in
weight of the filled bags.
2. Testing liner specimens in a top-pressure permeameter in which air
pressure of one or more atmospheres can be placed on a layer of
water or leachate covering a liner material.
3. Determining the permeabilities of membrane liners after swelling
specimens in water at room temperature and at 70°C to simulate
long exposure to leachate.
24
-------
The first of these methods is discussed and results are presented.
Initial experiments carried out with various heat-sealable liner
materials demonstrated the feasibility of the test procedure. Two series
of bags were then fabricated of heat-sealable lining materials. One set
was filled with leachate and the second set with 5% sodium chloride. The
liner materials in these tests include the following polymers: chlorinated
polyethylene, chlorosulfonated polyethylene, elasticized polyolefin,
polyester elastomer and polyvinyl chloride (3 different membranes).
Figure 7 shows a schematic of the bag assembly and Figure 8 is a
photograph of the bags and the necessary testing equipment.
The individual bags for the leachate were 20 x 14 cm, which gave an
exposable surface of approximately 560 cm2. For the sodium chloride
solution the bags were 17 x 12 cm, which yielded an exposable surface of
approximately 400 cm2.
Each bag was constructed with a neck through which the test fluid is
introduced. After the bag is filled, the neck is heat sealed. Leachate,
(100 ml), of the composition shown in Table 6, and 305-490 ml of 5% salt
solution were added to the respective bags.
TABLE 6. CHARACTERISTICS OF LEACHATE IN BAGSa
Property Value
Total solids, % 2.0
Total volatile solids, % 1.1
Chemical oxygen demand, g/1 35.7
Total volatile acids, g/1 15.2
PH 5.15b
Conductivity, Umho 11,500
a
Amount of leachate in each bag is 100 ml.
Samples were taken from the blend of leachates
collected on November 8, 1976.
Average value for the leachates taken from the
12 generators.
The following tests were performed during the exposure of these bags:
1. The deionized water was tested periodically for pH, conductivity,
and for the odor of butyric acid, in the case of the inner bags
containing leachate.
25
-------
INNER BAG
MEMBRANE UNDER TEST
LEACHATE OR
NaCI SOLUTION
(INSIDE INNER BAG)
DEIONIZED WATER
OUTER BAG
POLYBUTYLENE
Figure 7. Schematic of osmosis bag assembly, showing inner bag made of
membrane material under test. The inner bag is filled with
leachate or 5% salt solution and sealed at the neck. The
outer polybutylene bag, which can be easily opened, is filled
with deionized water. The water in the outer bag is monitored
for pH and conductivity; the inner bag is monitored for weight
change.
26
-------
Figure 8. Osmosis bag and auxiliary equipment for monitoring.
27
-------
2. The bags containing the test fluid were removed periodically from
the water and weighed.
Results of the tests after extended exposures are given in Tables 7-10.
In the case of the bags containing leachate, after 500 days of exposure
it was apparent that there was movement through the liner by both the water
and the dissolved ingredients of the leachate (Table 7). An increase in
electrical conductivity occurred, indicating the permeation of some ions
from the leachate into the deionized water. Also, there was an increase in
the weight of the bags containing the leachate, indicating permeation of
water into the bags containing leachate. In.this series, the elasticized
polyolefin yielded the lowest transmission of water and of dissolved
components and the chlorinated polyethylene appears to be the most
permeable. The order of the liner materials is shown in Table 8 for
increasing conductivity of the deionized water and for the increase in
the weight of the bags -shown in Table 8.
TABLE 8. TESTS OF BAGS CONTAINING LEACHATE - ORDER OF LINERS BY
INCREASING BAG WEIGHT AND BY CONDUCTIVITY OF DEIONIZED WATER
Order of Conductivity of
increase deionized water Weight of bag
1 Elasticized polyolefin (#36) Elasticized polyolefin (#36)
2 Polyvinyl chloride (#59) Polyvinyl chloride (#11)
3 Polyvinyl chloride (#11) Polyvinyl chloride (#59)
4 Polyester elastomer (#75) Polyvinyl chloride (#17)
5 Chlorinated polyethylene (#77) Polyester elastomer (#75)
6 Polyvinyl chloride (#17) Chlorinated polyethylene (#77)
Somewhat similar results were obtained when the inner bags were filled
with 5% sodium chloride solution (Table 9). Again, the elasticized poly-
olefin was the most impermeable of the liners and one of the polyvinyl
chloride membranes (#11) was the second most impermeable. The order
for the liners in this set is shown in Table 10 for increasing conductivity
of the deionized water and increasing weight in the bags.
28
-------
to
TABLE 7. TESTS OF MEMBRANE LINER BAGS FILLED WITH LEACHATE - PERMEABILITY
OF MEMBRANES TO WATER AND TO IONS DUE TO OSMOSIS
Original values Values at 70 days Values at 500 davs
Conduc- Weight of Conduc- Weight Conduc-
Liner w tivityb, filled bag, tivity*1, increase0, tivitA
Polymer no. pH* ymho g pHb umho g pHb pmho
Chlorinated
polyethylene 77 5.7 5.2 170.91 5.8 29.7 1.68 6.5 124.0
Elasticized
polyolefin 36 5.1 4.3 142.63 5.0 9.82 -0.07 4.5 17.8
Polyester
elastomer 75 4.0 20.5 112.25 3.5 73.0 0.58 6.4 50.0
Polyvinyl
chloride 11 5.8 6.0 166.88 4.4 30.9 0.41 6.0 32.0
Polyvinyl
chloride 17 5.0 13.3 138.28 2.9 310.1 0.33 2.8 325.0
Polyvinyl
chloride 59 5.7 5.9 170.14 3.8 61.5 0.97 6.3 23.2
Blank " 5'5 1-33 - 5.7 1.75 - 4.3 11.6
Weight
increase ,
g
4.74
0.22
2.95
1.12
1.37
1.21
a ^ ~
bArea of each bag exposed to test fluid is 560 cm.
CPH and conductivity of deionized water outside the bags containing leachate.
Weight increase of bags containing leachate.
-------
CO
o
TABLE 9. TESTS OF MEMBRANE LINER BAGS FILLED WITH 5% NaCl SOLUTION -
PERMEABILITY OF LINERS TO WATER AND TO IONS DUE TO OSMOSIS
Polymer
Chlorinated
polyethylene
Chlorosulfonated
polyethylene
Elasticized
polyolefin
Polyester elastomer
Polyvinyl chloride
Polyvinyl chloride
Blank
Line;
no.
77
6
36
75
11
59
Original
Conduc-
tivity13,
ymho
1.92
3.48
1.51
1.62
1.67
1.77
0.63
values
Weight of
filled bag,
g
370.91
391.02
329.50
424.35
479.81
537.80
Values at
Conduc -
tivityb,
ymho
23.3
86.0
9.5
22.9
13.7
19.5
7.8
113 days
Weight
c
xncrease ,
g
1.01
1.36
-0.02
2.61
0.26
1.07
"" ""
Values at
Conduc-
tivity13,
Vimho
31.2
113.0
10.9
30.0
15.3
21.5
6.6
200 days
Weight
increase0 ,
g
+1.56
+2.20
+0.06
+5.30
+0.69
+1.86
"
*Area of bag exposed to test fluid was 480 cm .
""conductivity of deionized water outside the test bags.
'Weight increase of bags.
-------
TABLE 10. TEST OF BAGS CONTAINING 5% SALT SOLUTION - ORDER OF LINERS BY
INCREASING BAG WEIGHT AND BY CONDUCTIVITY OF DEIONIZED WATER
Order of Conductivity of
increase deionized water Weight of bag
1 Elasticized polyolefin (#36)a Elasticized polyolefin (#36)
2 Polyvinyl chloride (#11) Polyvinyl chloride (#11)
3 Polyvinyl chloride (#59) Chlorinated polyethylene (#77)
4 Polyester elastomer (#75) Polyvinyl chloride (#59)
5 Chlorinated polyethylene (#77) Chlorosulfonated polyethylene
(#6)
6 Chlorosulfonated polyethylene (#6) Polyester elastomer (#75)
_^ . ___ .
Membrane liner identification number.
After the completion of individual tests, the bags will be cut,
physical properties of the liner materials will be determined, and the
leachate will be analyzed.
This may be a good laboratory test for assessing membrane liner
materials. It is planned to extend this work to include additional membrane
liners, including rubber membranes which must be cemented. A similar series
of tests is now underway on various hazardous wastes.
WATER ABSORPTION OF MEMBRANE LINER MATERIALS
The swelling of a rubber or plastic membrane liner generally results
in a reduction of desired physical properties as well as an increase in
permeability. Severe swelling over a long period of time could ultimately
cause the failure and non-performance of a polymeric liner material. When
materials are evaluated for specific liner applications their swelling
should be studied under various conditions.
During the first year of exposure in the simulated landfills, some of
the specimens showed significant absorption of leachate. A concurrent test
run in the laboratory of some of the same liner materials in water showed
similar absorption, although the order of increasing swell was not the
same. These data were presented in the Second Interim Report (2), along
with absorption data run at 100°C. Raising the test temperature during
immersion accelerated the rate of water absorption. It was hoped that a
short-term test of two hours would indicate the swelling characteristics
of a liner material, but the results did not correlate with either the room
temperature data or with the cell exposure.
31
-------
The temperature used was felt to be too high. Consequently, another
series of swell tests was run, in accordance with ASTM D570, at room
temperature and at 70°C. The results of swelling up to 100 weeks are shown
in Table 11. Generally, the immersion at room temperature and at 70°C
resulted in essentially the same order of increasing swelling; the cor-
relation was significantly better than immersion at 100°C, as shown in
Table 12.
TABLE 12. ORDER OF INCREASED SWELLING IN WATER
AT ROOM TEMPERATURE AND AT 70°Ca
Order of
increased
swelling
At room temperature
At 70°C
1 Polyvinyl chloride (#11)
2 Polyester elastomer (#75)
3 Ethylene propylene rubber (#8)
4 Ethylene propylene rubber (#26)
5 Polyvinyl chloride (#59)
6 Elasticized polyolefin (#36)
7 Butyl rubber (#57)
8 Chlorinated polyethylene (#77)
9 Chlorosulfonated polyethylene
(#6)
Polyester elastomer (#75)
Elasticized polyolefin (#36)
Ethylene propylene rubber (#26)
Ethylene propylene rubber (#8)
Polyvinyl chloride (#59)
Polyvinyl chloride (#11)
Butyl rubber (#57)
Chlorinated polyethylene (#77)
Neoprene (#82)
10
11
Neoprene (#43)
Neoprene (#82)
Chlorosulronatea poxyetnyj-ene
(#6)
Neoprene (#43)
ASTM D570.
One of the major differences in the results obtained at the two tem-
peratures was in one of the polyvinyl chloride liners which at room
temperature yielded the lowest swelling, but at 70°C was sixth in swelling.
The materials that had the lowest swell were polyvinyl chloride, elasticized
polyolefin, and ethylene propylene rubber. Those swelling the most were
neoprene, chlorosulfonated polyethylene, and chlorinated polyethylene.
These exposures are being continued and will be supplemented by limited
physical testing of the highly swollen materials to determine the relation-
ship of physical properties to the degree of swelling.
32
-------
TABLE 11. WATER ABSORPTION OF SELECTED MEMBRANE LINER MATERIALS AT ROOM TEMPERATURE AND AT 70
o_a
to
Co
Water absorbed. %
At room temperature
Polymer
Butyl rubber
Chlorinated polyethylene
Chlorosulfonated poly-
ethylene
Elasticized polyolefin
Ethylene propylene rubber
Neoprene
Polyester elastomer
Polyvinyl chloride
Liner
No.
57
77
6
36
8
26
43
82
75
11
59
1
week
0.82
1.63
3.44
0.39
0.50
1.20
3.80
2.43
1.07
1.29
1.59
11
weeks
3.22
5.53
6.97
0.52
1.30
1.84
13.62
8.29
1.05
1.10
2.34
44
weeks
4.50
10.2
10.9
0.0
1.56
1.49
37.8
18.5
0.67
0.70
2.43
100
weeks
6.4
12.5
16.3
4.5
2.25
2.56
75.1
32.1
1.31
1.25
2.98
1
day
2
3
5
0
0
0
3
2
1
1
2
.04
.04
.68
.24
.42
.74
.89
.49
.18
.51
.09
by weiaht
1
week
4.62
15.9
22.1
0.36
1.11
1.44
14.1
8.11
1.28
5.59
4.87
At 70°C
11
weeks
17.54
58.4
131.0
0.45
3.55
4.52
107.0
47.4
1.10
12.13
8.25
44
weeks
53.9
140.0
245.6
0.57
10.8
11.20
240.0
191.4
0.72
39.2
24.0
100
weeks
103.2
179.3
370.5
8.7
17.8
17.4
(b)
295.0
0.22
87.4
25. 5C
OL ___
ASTM D570-63 specimens 1x2 in. in deionized water.
Specimens began to disintegrate between 44th and 69th weeks.
Specimens have become hard, indicating loss of plasticizer.
-------
The immersion tests described earlier also furnish information for com-
parison with these swelling data. In Table 13, for example, liners that
have been swollen in both water and leachate are compared. The liner
materials immersed in the leachate swelled significantly more in 32 weeks
than did the same materials immersed in deionized water for 44 weeks. This
difference is probably due to the organic content of the leachate.
TABLE 13. COMPARISON OF THE SWELLING OF MEMBRANE LINING MATERIALS
IMMERSED IN WATER AND IN LEACHATE
Polymer
Chlorosulfonated polyethylene
Elasticized polyolefin
Ethylene propylene rubber
Polyester elastomer
Polyvinyl chloride
Liner
no.
6
36
8
75
11
Swelling,
In water
for 44 weeks
10.9
0
1.6
0.67
0.70
%
In leachate
for 32 weeks
13.3
0.1
6.0
2.0
2.9
Extended exposures at 70 C were run to determine whether there is a
tendency on the part of liner materials to reach a plateau of swelling with
respect to time. Chlorinated polyethylene and ethylene propylene rubber
appeared to have essentially plateaued. One of the polyvinyl chloride
liners appeared to have come to a maximum value; however, it hardened,
presumably from loss of plasticizer. The neoprene and chlorosulfonated
polyethylene specimens appeared to continue to swell. The elasticized
polyolefin absorbed little during the first 400 days; after that, it began
to swell. This swelling test of the liners is being continued. Also, one
of the three specimens of each of the polyvinyl chloride liners will be
analyzed for loss of plasticizer.
MONITORING THE LEAChATE GENERATORS
In November 1975, after one year of operation. 12 of the 24 original
leachate generators - liner exposure cells were disassembled and the
exposed liner specimens were recovered and tested (2, 4). Monitoring of
the 12 remaining generators has continued:
1. Every two weeks, 2 gal tap water were added to simulate 1 in.
rainfall. Over the year, this is equivalent to 26 in. of rain
entering the landfill, a condition which exists in the Pacific
northwest.
34
-------
2. Records were made of leachate output, ambient temperature,
temperature within two generators, and level of refuse and
cover within the generators.
3. The leachate was analyzed approximately once a month for percent
total solids, percent volatile solids, total volatile acids,
chemical oxygen demand, and pH.
4. The seepage of the leachate through the liner was measured.
Collection of Leachate
The leachate is collected continuously in bags prepared from polybuty-
lene. These bags replaced the polyethylene bags that failed at the heat-
sealed seams. A constant head of 1 ft of leachate was maintained by
allowing the leachate to pass through an inverted U-tube placed in the out-
flow line at 1 ft above the lining. During recent months, gas was generated
in the bases and bags causing the bags to inflate. To prevent a buildup of
excess pressure and failure of the bags, relief valves were installed, as
shown in Figure 9. Since the installation of these valves there has been
no leakage of the bags.
Leachate Characteristics
The leachate has been analyzed on approximately a monthly basis since
the cells reached "field capacity" in November 1974. Average analytical
results for solids, pH, volatile acids, and chemical oxygen damand are
presented in Figures 10 through 13, respectively. During the first year
of operation, the characteristics of the leachate remained constant except
the volatiles acid content, which increased. Since that time, there has
been a reduction in the solids, total volatile acids, and chemical oxygen
demand, and a rise in pH. The early leachate contained a relative high
concentration of butyric acid, which seems to be essentially absent in the
more recent leachate.
Consolidation of Refuse
During the course of the operation of the generators, considerable
consolidation of the shredded refuse has occurred within the generators, as
shown in Figure 14. This consolidation has been essentially linear with
time, although there are indications that this consolidation is slowing
down. At the end of 180 weeks of leachate production, the consolidation
averages about 16% for the refuse in the 12 generators.
Seepage of Leachate
One of the primary design features of the leachate generator - exposure
cells is the capability of their functioning as large permeameters. The
liner specimens were sealed in the bases of the generators to prevent by-
passing of the liners.
35
-------
VENTED TO ATMOSPHERE f
1 FOOT ABOVE LINING
MOUNTED IN CELL
LEACHATE FROM
GENERATOR
POLYBUTYLENE COLLECTION BAG
Figure 9. Leachate collection bag with water seal and vent to prevent excessive gas pressure build-
up in the bag. The seal prevents air from entering the bag and oxidizing the leachate.
-------
LJ
O
O
V)
to
NON-VOLATILE SOLIDS
1976
ELAPSED
1978
TIME
Figure 10. Average solids contents of the leachate produced in the generators, November 1974 - May 1978
The data for November 1974 - November 1975 are the averages for the leachate from 24 generators
Twelve generators were disassembled in November 1975 and, consequently, the data for December
1975 - May 1978 are the averages for the leachates from the 12 remaining generators
-------
w 5.5--|
oo
4.5
1976
ELAPSED TIME
1977
1978
Figure 11. Average pH of the leachate produced in the generators, November 1974 - May 1978. The data
from November 1974 - November 1975 are the averages for the leachates from 24 generators. The
data for December 1975 to May 1978 are the averages for the leachate from 12 generators.
-------
|1974|
Figure 12.
1975
1976
ELAPSED TIME
1978
Average total volatile acids content (TVA), as acetic acid, of the leachate produced in the gen-
erators, November 1974 - May 1978. The data for November 1974 - November 1975 are the averages
for the leachates from 24 generators. The data for December 1975 - May 1978 are the averages
for the leachates from 12 generators.
-------
60
1977
1978
Figure 13.
1976 |
ELAPSED TIME
Chemical oxygen demand (COD) of the leachate produced in the generators, November 1974 - May 1975.
The data for November 1974 - November 1975 are the averages for the leachates from 24 generators.
The date for December 1975 through May 1978 are the averages for the leachates from 12 generators.
-------
0
ELAPSED TIME
Figure 14. The average refuse consolidation in the leachate generators, November 1974 - May 1978. The data
for November 1974 - November 1975 are averages for the refuse in the 24 generators. The data for
December 1975 and later are the averages for the consolidation in 12 generators.
-------
A constant head of one ft of leachate is maintained above the liner to
supply a driving force for the fluids through the liner specimens. Perme-
ability of the liner can, therefore, be determined by collecting the
leachate below it.
The results of the cumulative collection of the leachate below the
liner specimen is reported in Table 14. The seals in two of the generators,
#1 and #3, in which polyethylene and butyl rubber are being exposed
respectively, appear to have failed. The epoxy resin that was used to make
the seal probably disintegrated in much the same fashion as occurred in two
of the first 12 generators that were previously dismantled. The mercaptan
epoxy resin that was used to achieve rapid set does not have high chemical
resistance and is sensitive to off-ratios between the resin and hardener.
Although the leachate is being collected from drains below these liners,
it is still being ponded on the liners to keep them immersed in leachate.
The remaining cells appear to be functioning properly with only three
showing seepage; i.e., polyvinyl chloride, soil cement, and soil asphalt.
TABLE 14. CUMULATIVE COLLECTION OF LEACHATE BELOW
LINERS MOUNTED IN BASES OF GENERATORS3
Generator
no.
1
2
3
4
5
6
7
8
9
10
11
12
Liner Material
Polyethylene (#21)b
Polyvinyl chloride (#17)
Butyl rubber (#7)
Chlorosulfonated polyethylene (#6)
Ethyl ene propylene rubber (#18)
Chlorinated polyethylene (#12)
Paving asphalt concrete (2 in. thick)
Hydraulic asphalt concrete (2 in. thick)
Soil cement (4.5 in. thick)
Soil asphalt (4 in. thick)
"Cat" blown asphalt membrane (0.25 in. thick)
Emulsion asphalt on fabric (0.25 in. thick)
Amount of leachate
collected, kg.
(c)
1.27
(c)
0
0
0
0
0
0.23
1.33
0
0
^From November 21, 1974, to May 31, 1978.
Membrane liner identification number.
Leachate appears to be by-passing the liners and is being collected from
drains below the liners.
42
-------
At the conclusion of the exposure (now planned for June 1979) , it will
be possible to determine whether there has been any failure in the liners
or if, in fact, the epoxy resin seal disintegrated.
RECOVERY AND TESTING OF SAMPLES OP A POLYVINYL CHLORIDE LINER FROM A
DEMONSTRATION LANDFILL
Information from the field regarding the performance of artificial
lining materials on long exposure to sanitary landfill leachate has been
very limited. First, such use for these liners, particularly the polymeric
membranes, is relatively new, dating from the early 1970's. Second,
effective and economic methods of retrieving specimens and repairing
linings at the bottoms of landfills have not been developed.
A demonstration landfill in Crawford County, Ohio, placed in the spring
of 1971, was lined with a polyvinyl chloride liner. The liner from this
landfill was relatively accessible as the total fill contained one lift of
8 ft of refuse and was about 12 ft deep, including the cover. This
demonstration landfill had been designed to compare conventionally processed
solid waste with rough and compacted wastes. The various types of refuse
had been placed in essentially waterproof cells lined with plastic membranes.
The effect of water content on consolidation and decomposition of the refuse
was to be determined. However, all of the cells were flooded with water in
a heavy rainfall just before the fill was closed. Thus, the original
objectives could not be met and the project was terminated.
In view of the relative accessibility of the liner, the landfill was
opened in May 1977, after six years, and the membrane liner was recovered.
The cells appeared to have retained the water. The condition of -the refuse
did not appear to be typical of sanitary landfills. The odor was mild, and
the refuse showed little deterioration. The samples of liners recovered
from the cells appeared to be in excellent condition with little difference
apparent between samples taken from the top of the cell, above the refuse,
and those taken from the bottom, below the refuse. The top liner had been
under 3 ft of clay cover, and the bottom liner had been under about 2 ft of
clay and was on top of pea gravel. Both liners had taken the shape of soil
and gravel without breaking. The depressions were as much as 6 in. deep
in a 1 ft area in the exposed top liner.
These samples were analyzed along with a sample of polyvinyl chloride
sheeting that was thought to have been in the same lot as the material used
for lining the cells. However, the results, (Table 15) show that the two
specimens taken from the fill were very similar and considerably different
in composition from the unexposed sample, indicating that it was not a
control for the liner. As Table 16 and Appendix B show, the amount of
swelling and the decrease in properties of the lining were within the spread
of values observed in the leachate immersion test for seven polyvinyl
chloride materials. The specimen taken from the bottom was probably not in
43
-------
TABLE 15. ANALYSES OF POLYVINYL CHLORIDE LINER RECOVERED
FROM DEMONSTRATION LANDFILL IN CRAWFORD COUNTY, OHIO
Property
Volatiles (2 h at 105°C) , %
Specific gravity (dry basis)
Ash (dry basis), ASTM D297, %
Extractables, ASTM D3421b, %
Pyrolysisc:
Polymer and organic
content, %
Polymer content, %
Carbon black, %
Ash, %
Unexposeda
liner
(#95)
0.10
1.379
10.26
7.54
80.6
73.1
8.6
10.9
Composition
Liner from
top of fill
(#96)
0.41
1.260
6.14
34.10
87.0
52.9
6.7
6.4
Liner from
bottom of fill
(#97A)
1.33
1.265
6.01
34.43
89.0
54.6
4.4
6.8
Shelf, indefinite exposure in shop.
Modified: 20 h refluxing with mixed solvent of carbon tetrachloride
(CC1 ):methyl alcohol (CT^OH), 2:1.
f-»
Test method: Reference 6.
direct contact with the leachate in the fill during the 6 years it was in
place. The 2 ft soil layer above the liner was a highly impermeable clay
having a permeability coefficient of 1.4 x 10~7 cm/sec. The clay layer
and the weak leachate created a situation that was not typical of what
might be anticipated for a liner in a fullscale landfill.
44
-------
Ui
TABLE 16. PROPERTIES OF POLYVINYL CHLORIDE LINER RECOVERED FROM A
DEMONSTRATION LANDFILL IN CRAWFORD COUNTY, OHIO
Property
Thickness, mils
Tensile strength, psi
Elongation at break, %
Set at break, %
S-100, psi
S-200, psi
S-300, psi
Tear strength, ppi
Hardness (Duro A) , instant
Puncture resistance, Ib
Elongation, in.
Seam strength (shear) , ppi
Locus of failure
Test
method
ASTM D412
ASTM D412
ASTM D412
ASTM D412
ASTM D412
ASTM D412
ASTM D624
ASTM D2240
Fed Std 101
-B-2065
ASTM D413
Liner from
top of fill
(#96)
Machine
30
2665
340
66
1290
1830
2245
374
77
41.4
0.66
49.5
SEa
Transverse
2600
360
79
1245
1750
2300
370
Liner from
bottom of fill
(#97A)
Machine
28
2550
325
55
1185
1785
2400
343
78
37.3
0.65
45.5
BRKb
Transverse
__
2475
350
70
1085
1605
2205
341
__
Break at seam.
Break in tab.
-------
REFERENCES
1. Haxo, H. E., and R. M. White. First Interim Report: Evaluation of Liner
Materials Exposed to Leachate. EPA Contract 68-03-2134, unpublished, 1974.
2. Haxo, H. E., and R. M. White. Second Interim Report: Evaluation of Liner
Materials Exposed to Leachate. EPA-600/2-76-255, U. S. Environmental Pro-
tection Agency, Cincinnati, Ohio, 1976. NTIS No.: PB259-913.
3. Haxo, H. E. Assessing Synthetic and Admixed Materials for Lining Land-
fills. In: Gas and Leachate from Landfills: Formulation, Collection and
Treatment. EPA 600/9-76-004, U. S. Environmental Protection Agency,
Cincinnati, Ohio, 1976. NTIS No.: PB251-161.
4. Haxo,H.E. Compatibility of Liners with Leachate. In: Management of Gas
and Leachate in Landfills, Proceedings of the Third Annual Municipal
Solid Waste Research Symposium, EPA-600/9-77-026, U. S. Environmental
Protection Agency, Cincinnati, Ohio, 1977. NTIS No.: PB272-595.
5. ASTM E96-66 (1972). Tests for Water Vapor Transmission of Materials in
Sheet Form. Parts 18, 20, 35, and 41. American Society for Testing and
Materials, Philadelphia, PA, 1977.
6. Wake, W. C. The Analysis of Rubber and Rubber-like Polymers. Wiley In-
terscience, New York, N.Y., 2nd Edition, 1968.
46
-------
APPENDIX A. PROPERTIES OF UNEXPOSED POLYMERIC MEMBRANES IN PROJECT
Item
b
Liner No.
Thickness, mils
Tensile strength, psi
Elongation at break, %
Set at break, %
S-100, psi
S-200, psi
S-300, psi
Tear strength, ppi
Hardness, Duro A:
Instant reading
10-sec. reading
Puncture resistance, Ib
Elongation, in.
Specific gravity
Ash (dry basis) , %
Volatiles, %
Exposure tests
Direction
of test
-
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
_
-
-
-
-
-
-
Chlorinated
12
31
2460
2080
300
520
199
230
1220
520
1820
840
2460
1200
270
240
85
77
47.0
1.04
1.360
14.40
0.10
P,S,I
38
32
2190
2000
340
505
192
201
1345
565
1640
770
2005
1065
252
213
82
76
47.8
0.86
1.336
11.83
0.24
I
polyethylene
77
29
2055
2340
325
480
140
160
1240
560
1540
820
1955
1205
273
239
87
80
43.9
0.94
1.362
12.56
(d)
L,N
86
22
1845
1510
355
595
208
235
870
275
1210
405
1575
605
187
178
76
67
20.9
0.91
1.377
17.37
O'.OS
I
Chlorosulfonated
polyethylene
3C
31
1710
1430
580
640
370
380
670
520
850
620
1030
760
290
270
86
83
25.4
1.16
1.433
33.45
0.84
S,I
6C
32
1770
1610
240
225
78
79
990
895
1715
1445
-
-
317
287
79
75
34.4
0.57
1.343
3.35
0.29
P,S,I,N
85
33
2345
2055
260
325
167
192
1150
750
2130
1410
-
2020
308
277
83
79
47.8
0.86
1.311
4.02
0.92
I
See footnotes at end of table.
47
-------
APPENDIX A (Continued). PROPERTIES OF UNEXPOSED POLYMERIC MEMBRANES IN PROJECT
a
Item
Liner No.
Thickness, mils
Tensile strength, psi
Elongation at break, %
Set at break, %
S-100, psi
S-200, psi
S-300, psi
Tear strength, ppi
Hardness, Duro A:
Instant reading
10-sec. reading
Puncture resistance, Ib
Elongation, in.
Specific gravity
Ash (dry basis) , %
Volatiles, %
Exposure tests
Direction
of test
_
-
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
-
-
-
-
-
-
-
Ethylene propylene rubber
8
62
1635
1550
520
500
14
11
350
320
800
740
1170
1110
206
111
62
58
51.8
1.36
1.173
6.78
0.38
S,I
18
49
1510
1440
420
400
13
9
350
350
760
760
1120
1120
181
181
57
54
39.4
1.44
1.122
5.42
0.50
P,S,I
83°
39
1066
870
20
240
59
51
-
630
-
845
-
-
303
276
73
70
33.6
0.61
1.199
0.32
0.31
I
91
37
1790
1865
500
475
10
11
300
375
795
915
1220
1370
196
195
55
52
29.2
1.17
1.160
7.33
0.34
I
41
20
3290
2720
700
650
495
438
950
920
1060
1020
1230
1180
429
417
84
81
25.1
0.96
0.938
0.93
0.16
I
Butyl
rubber
44
62
1625
1570
415
470
18
18
335
280
750
615
1210
1020
201
221
59
54
39.5
1.17
1.176
4.28
0.46
I
See footnotes at end of table.
48
-------
APPENDIX A (Continued). PROPERTIES OF UNEXPOSED POLYMERIC MEMBRANES IN PROJECT
a
Item
Liner No.b
Thickness, mils
Tensile strength, psi
Elongation at break, %
Set at break, %
S-100, psi
S-200, psi
S-300, psi
Tear strength, ppi
Hardness, Duro A:
Instant reading
10-sec. reading
Puncture resistance, Ib
Elongation, in.
Specific gravity
Ash (dry basis) , %
Volatiles , %
Exposure tests
Direction
of test
-
-
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
-
-
-
-
-
-
-
Neoprene
9
60
2320
2090
340
340
11
13
640
560
1320
1150
2060
1830
220
210
71
66
58.7
1.16
1.500
12.98
0.76
S,I
37
73
2400
2330
265
290
2
3
765
570
1800
1470
-
2400
221
199
69
67
80.4
1.02
1.451
3.31
0.64
I
42°
19
17420
9580
25
25
2
2
-
-
-
-
-
-
1545
1802
74
73
124.6
0.37
1.302
27.70
0.86
I
90
37
2185
2010
415
415
26
25
565
550
1450
1225
1895
1700
207
196
68
61
44.9
1.01
1.388
4.67
0.37
I
See footnotes at end of table.
49
-------
APPENDIX A (Continued). PROPERTIES OF UNEXPOSED POLYMERIC MEMBRANES IN PROJECT
a
Item
Liner No.
Thickness, mils
Tensile strength, psi
Elongation at break, %
Set at break, %
S-100, psi
S-200, psi
S-300, psi
Tear strength, ppi
Hardness, Duro A:
Instant reading
10-sec. reading
Puncture resistance, Ib
Elongation, in.
Specific gravity
Ash (dry basis) , %
Volatiles, %
e
Exposure tests
Direction
of test
_
-
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
_
-
-
-
-
-
-
Polyvinyl
11
30
2800
2550
350
350
90
103
1355
1205
1980
1740
2585
2255
374
370
85
79
37.4
0.63
1.275
6.20
0.11
S,I,L,
N
17
20
2640
2520
270
290
68
77
1260
1130
2080
1850
-
-
353
317
81
76
25.8
0.69
1.264
5.81
0.09
P,S,
I,L
19
22
2780
2260
330
340
97
105
1150
1060
1890
1590
2620
2170
295
275
80
72
24.0
0.71
1.231
3.65
0.05
S,I
40
33
2935
2640
385
400
62
71
1235
1115
1825
1610
2445
2150
350
316
81
74
43.1
0.72
1.289
8.09
0.21
I
chloride
59
33
2505
2365
370
400
45
60
1020
895
1570
1355
2160
1860
306
287
80
71
37.3
0.78
1.280
6.94
0.31
L,N
67
22
3020
2765
385
415
192
207
1250
1110
1820
1585
2430
2135
340
297
81
75
27.8
0.68
1.245
6.70
0.03
I
88
20
3395
2910
325
335
102
101
1870
1600
2610
2190
3230
2770
463
470
85
80
28.6
0.56
1.255
2.80
0.17
I
89
11
3715
3085
315
325
196
205
1845
1530
2715
2195
3520
2880
408
391
87
82
17.0
0.48
1.308
5.67
0.03
I
See footnotes at end of table.
50
-------
APPENDIX A (Continued). PROPERTIES OF UNEXPOSED POLYMERIC MEMBRANES IN PROJECT
a
Item
Liner No.
Thickness, mils
Tensile strength, psi
Elongation at break, %
Set at break, %
S-100, psi
S-200, psi
S-300, psi
Tear strength, ppi
Hardness, Duro A:
Instant reading
10-sec. reading
Puncture resistance, Ib
Elongation, in.
Specific gravity
Ash (dry basis) , %
Vola tiles, %
Exposure tests6
Direction
of test
-
-
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
-
-
-
-
Poly-
ethylene
21
11
1700
2590
320
690
177
667
1270
1030
1470
1050
1680
1120
415
360
97
97
13.9
0.76
PVC +
pitch
52
80
1185
1005
150
175
36
18
1175
860
-
-
-
-
292
208
75
69
62.3
0.49
0.931 1.294
-
-
-
0.00
0.36
P,S,I,
C,G
9.46
0.39
I
a ~~
Tests performed were tensile, elongation, modulus and
tear strength, ASTM D624;
puncture ,
bASTMD297; vola tiles (weight loss in
cContractor ' s liner number
^Fabric-reinf orced .
.
FM 101B, No.
2 h at 105°C)
2065;
.
Elasticized
polyolefin
36
23
2645
2540
675
650
460
430
880
865
975
960
1145
1150
388
369
90
87
26.3
0.97
0.938
0.90
0.15
I,L,N
set, ASTM D412;
Polyester
elastomer
75
7
6770
6765
560
590
340
370
2715
2455
2880
2585
3610
3315
911
782
93
93
29.9
1.30
1.236
0.38
0.26
I,L,N
Duro A, ASTM
specific gravity, ASTM D297
Poly-
butylene
98
8
5625
5580
390
375
346
331
2330
2360
3035
3200
4405
4610
355
380
94
93.7
13.9
0.66
0.915
0.08
0.12
I,C
D2240;
; ash ,
C, leachate collection bags; G, used as liner of all generators; I, in immersion test;
L, leachate osmosis bag; N, NaCl osmosis bag,- P, primary test specimens; S, secondary
test (specimens buried in sand).
51
-------
APPENDIX B. PROPERTIES OF MEMBRANE LINER MATERIALS AFTER 8 MONTHS IN LEACHATE
FROM SIMULATED MUNICIPAL SANITARY LANDFILLS.
Item
b
Liner No.
Thickness, mils
Leachate absorption, %
Increase in area, %
Volatiles, %
Tensile strength, psi
Elongation at break, %
Set at break, %
S-100, psi
S-200, psi
S-300, psi
Tear strength, ppi
Hardness, Duro A:
Instant reading
10-sec. reading
Puncture resistance, Ib
Elongation, in.
Specific gravity, dried
Ash (dry basis) , %
Direction
of test
-
-
-
-
-
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
-
-
-
-
-
Chlorinated polyethylene
12
36.0
9.5
3.3
7.9
2190
1660
340
460
195
195
1115
480
1525
735
1960
1065
210
200
81
72
50.7
1.00
1.354
14.52
38
36.0
10.2
3.0
8.3
1940
1860
340
480
185
165
1170
455
1465
680
1825
1025
185
170
82
75
50.1
0.99
1.335
12.06
86
23.0
8.5
3.0
7.5
1850
1740
480
380
130
140
760
320
1080
500
1460
800
150
145
74
66
27.1
1.06
1.389
18.08
Chlorosulfonated
polyethylene
3°
34.0
19.2
7.0
18.6
1790
1700
580
620
250
265
365
250
500
290
665
375
170
160
67
63
38.5
1.86
1.393
33.88
6C
33.5
13.3
4.6
1.21
2190
1920
230
240
75
75
940
775
1930
1620
-
-
250
210
74
71
48.7
0.76
1.325
2.10
85
35.0
14.4
8.8
12.6
1980
1680
250
320
60
90
875
485
1690
1030
-
1600
220
205
77
73
54.5
0.96
1.294
2.63
See footnotes at end of table.
52
-------
APPENDIX B (Continued). PROPERTIES OF MEMBRANE LINER MATERIALS AFTER 8 MONTHS
IN LEACHATE FROM SIMULATED MUNICIPAL SANITARY LANDFILLS.
a
Item
Liner No.
Thickness, mils
Leachate absorption, %
Increase in area, %
Vo la tiles, %
Tensile strength, psi
Elongation at break, %
Set at break, %
S-100, psi
S-200, psi
S-300, psi
Tear strength, ppi
Hardness, Duro A:
Instant reading
10-sec. reading
Puncture resistance', Ib
Elongation, in.
Specific gravity, dried
Ash (dry basis) r %
Direction
of test
-
-
-
-
-
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
-
-
-
-
-
Ethylene propylene rubber
8
66.0
6.0
3.6
2.9
1700
1660
480
510
18
18
415
355
925
820
1305
1200
195
195
64
60
55.1
1.26
1.168
6.35
18
50.0
8.4
4.8
6.0
1360
1460
350
380
9
9
385
360
865
815
1235
1195
125
135
56
53
43.1
1.18
1.113
5.36
83C
36.0
2.8
1.2
3.0
990
920
240
330
50
75
930
665
960
845
-
890
285
280
74
70
27.8
0.51
1.194
0.30
91
36.0
20.9
13.5
12.7
3410
2380
460
360
20
15
730
330
1750
1355
2565
2085
160
165
58
54
27.5
1.12
1.110
6.38
41
19.5
0.5
-0.1
0.3
3080
2480
700
640
485
435
940
930
1070
1000
1225
1140
375
345
85
82
25.2
0.84
0.935
0.98
Butyl
rubber
44
67.5
1.8
0.3
1.4
1470
1520
440
490
20
25
295
240
635
540
1055
910
185
195
59
54
37.9
1.13
1.172
4.29
See footnotes at end of table.
53
-------
APPENDIX B (Continued). PROPERTIES OF MEMBRANE LINER MATERIALS AFTER 8 MONTHS
IN LEACHATE FROM SIMULATED MUNICIPAL SANITARY LANDFILLS
a
Item
b
Liner No.
Thickness, mils
Leachate absorption, %
Increase in area, %
Vo la tiles, %
Tensile strength, psi
Elongation at break, %
Set at break, %
S-100, psi
S-200, psi
S-300, psi
Tear strength, ppi
Hardness, Duro A:
Instant reading
10-sec . reading
Puncture resistance, Ib.
Elongation, in.
Specific gravity, dried
Ash (dry basis) , %
Direction
of test
-
-
-
-
-
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
_
-
-
-
-
Neoprene
9
70.5
19.3
14.4
9.0
1720
1450
300
280
9
8
400
310
1060
890
1690
1470
105
95
59
55
63.9
1.21
1.436
10.58
37
72.5
1.2
0.4
2.1
2380
2340
260
300
3
4
770
580
1765
1500
-
2335
215
220
74
72
90.6
1.11
1.459
5.33
42C
20.5
13.2
0.8
13.3
13510
2800
20
50
1
5
-
-
-
-
-
-
1245
1285
73
71
82.5
0.35
1.275
26.31
90
37.5
7.1
4.5
7.2
2130
1890
400
390
25
25
310
405
1380
1110
1890
1625
170
155
68
60
49.6
1.05
1.388
4.51
See footnotes at end of table.
54
-------
APPENDIX B (Continued). PROPERTIES OF MEMBRANE LINER MATERIALS AFTER 8 MONTHS
IN LEACHATE FROM SIMULATED MUNICIPAL SANITARY LANDFILLS.
Item3
Liner No.
Thickness, mils
Leachate absorption, %
Increase in area, %
Volatiles, %
Tensile strength, psi
Elongation at break, %
Set at break, %
S-100, psi
S-200, psi
S-300, psi
Tear strength, ppi
Hardness, Duro A:
Instant reading
10-sec . reading
Puncture resistance, Ib
Elongation, in.
Specific gravity, dried
Ash (dry basis) , %
Direction
of test
-
-
-
-
-
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
-
-
-
-
-
Polyvinyl chloride
11
31.0
2.9
2.4
2.4
2940
2700
360
380
95
100
1330
1255
1915
1770
2505
2345
360
350
85
80
43.6
0.69
1.277
6.45
17
21.5
2.3
1.9
2.3
2560
2320
340
350
60
65
1150
990
1695
1440
2335
2000
300
305
79
74
32.5
0.78
1.268
5.39
19
21.5
1.6
1.9
0.9
2720
2490
380
440
80
105
1145
970
1680
1410
2170
1865
290
265
77
72
24.8
0.64
1.231
3.64
40
32.5
1.2
1.4
1.4
2670
2430
390
390
65
75
1105
980
1650
1470
2200
1955
315
275
82
75
45.5
0.80
1.287
6.63
67
22.0
1.6
0.4
1.4
2850
2660
380
440
85
110
1125
1010
1685
1460
2280
2000
285
285
80
74
29.8
0.73
1.246
5.39
88
20.0
1.0
0.5
2.4
3220
2660
340
360
90
100
1460
1140
2130
1665
2840
2275
345
330
84
79
28.7
0.60
1.251
2.81
89
11.0
2.5
1.1
2.3
3560
3160
310
350
90
110
1710
1455
2570
2165
3420
2870
340
320
87
83
20.1
0.70
1.288
5.59
See footnotes at end of table.
55
-------
APPENDIX B (Continued). PROPERTIES OF MEMBRANE LINER MATERIALS AFTER 8 MONTHS
IN LEACHATE FROM SIMULATED MUNICIPAL SANITARY LANDFILLS.
Itema
b
Liner No.
Thickness, mils
Leachate absorption, %
Increase in area, %
Volatiles, %
Tensile strength, psi
Elongation at break, %
Set at break, %
S-100, psi
S-200, psi
S-300, psi
Tear strength, ppi
Hardness, Duro A:
Instant reading
10-sec . reading
Puncture resistance, Ib
Elongation, in.
Specific gravity, dried
Ash (dry basis) , %
Direction
of test
-
-
-
-
-
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
Machine
Transverse
_
-
-
-
Poly-
ethylene
21
12.5
0.6
-0.2
0.0
3090
2880
580
660
455
520
1370
1175
1465
1220
1685
1255
405
360
90
90
15.9
0.99
0.928
0.03
PVC +
pitch
52
83.5
5.8
4.0
6.1
1090
920
200
190
40
15
990
745
1090
930
-
-
225
175
73
67
53.6
0.51
1.290
9.65
Elasticized
polyolefin
36
23.0
0.1
0.6
0.4
2480
2180
620
590
430
385
940
895
1030
975
1195
1130
390
380
89
87
28.5
1.02
0.938
0.93
Polyester
elastomer
75
6.0
2.0
1.3
1.4
6720
7760
580
640
360
345
2455
2665
2745
2835
3010
3665
740
625
89
89
19.6
1.11
1.232
0.33
Poly-
butylene
98
8
0.1
0.4
-0.2
5420
5500
380
360
230
210
2395
2420
3015
3305
4375
4735
410
400
92
91
20.2
0.74
0.904
0.01
Tests performed were tensile, elongation, modulus and set, ASTM D412; Duro A, ASTM D2240;
tear strength, ASTM D624; puncture, FM 101B, No. 2065; specific gravity, ASTM D297; ash,
ASTM D297; volatiles (loss to constant weight at room temperature, plus loss in weight in
b2 h at 1Q5°C).
Contractor's liner number.
Fabric reinforced.
56
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-79-038
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
LINER MATERIALS EXPOSED TO MUNICIPAL SOLID
WASTE LEACHATE
Third Interim Report
5. REPORT DATE
July 1979 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Henry E. Haxo, Jr., Robert S. Haxo, Thomas F. Kellogg.
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Matrecon, Inc.
P. 0. Box 24075
Oakland, CA 94623
10. PROGRAM ELEMENT NO.
1DC818, SOS 1, Task 20
11. CONTRACT/GRANT NO.
68-03-2134
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research LaboratoryGin, OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Interim 1/1/76 to 5/31/78
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
See also "Evaluation of Liner Materials Exposed to Leachate", EPA 600/2-76-255
September 1976. NTIS PB-259913 Project Officer: Robert Landreth (513)684-7871
ABSTRACT
This report is the third interim report of a project that aims to assess the
effects upon various liner materials of extended contact with leachate from simulated
sanitary landfills. In this part of the study, the primary exposure tests of liner
specimens at the bottom of simulated landfills were supplemented by immersion of 28
different polymeric materials in sanitary landfill leachate. Immersed membranes were
tested for changes in physical properties, permeability, and water absorption.
The results of the immersion tests generally confirm the earlier results for
membrane liner materials exposed for one year in simulated landfills.
Also reported are results of the water vapor permeability testing of 28 membrane
liners, the water absorption of a series of membranes at room temperature and at 70°C,
and the retrieval and testing of samples of a 6-year old membrane liner from a demon-'
stration landfill. The monitoring of the simulated landfills during 180 months of
operation is described and the analyses of the leachates produced during the period
of operation are summarized.
A simple bag test for assessing permeability and physical properties of membrane
liners for landfills is described and test results are presented.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Inings, Leaching, Refuse Disposal,
Pollution, Decomposition Reactions,
lastics
b.lDENTIFIERS/OPEN ENDED TERMS
Solid Waste Management
c. COSATI Field/Group
13B
DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
67
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (Rev. 4-77)
57
4 U.S. GOVERNMENT PRINTING OFFICE: 1979-657-060/5339
------- |