EPA/600/2-91/040
August 1991
COMPATIBILITY OF FLEXIBLE MEMBRANE LINERS
AND
MUNICIPAL SOLID WASTE LEACHATES
by
Henry E. Haxo, Jr.
Matrecon, Inc.
Alameda, CA 94501
Contract No. 68-03-3413
Work Assignment No. 24
Project Officer
Robert E, Landreth
Waste Minimization, Destruction, and Disposal Research Division
Risk Reduction Engineering Laboratory
Cincinnati, OH 45268
RISK REDUCTION ENGINEERING LABORATORY
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
CINCINNATI, OHIO 45268
-------
DISCLAIMER
The information in this document has been funded wholly or in part by
the United States Environmental Protection Agency under Contract No.
68-03-3413 to PEI Associates; work assignment 24 to Matrecon, Inc. It has
been subjected to the Agency's peer and administrative review, and it has been
approved for publication as an EPA document. Mention of trade names or
commercial products does not constitute endorsement or recommendation for use.
i i
-------
FOREWORD
Today's rapidly developing and changing technologies and industrial
products and practices frequently carry with them the increased generation of
solid and hazardous wastes. These materials, if improperly dealt with, can
threaten both public health and the environment. Abandoned waste sites and
accidental releases of toxic and hazardous substances to the environment also
have important environmental and public health implications. The Hazardous
Waste Engineering Research Laboratory assists in providing an authoritative
and defensible engineering basis for assessing and solving these problems.
Its products support the policies, programs and regulations of the Environ-
mental Protection Agency, the permitting and other responsibilities of State
and local governments and the needs of both large and small businesses in
handling their wastes responsibly and economically.
This report summarizes the results of a survey of the open technical
literature relating to the compatibility of flexible membrane liners (FML)
with municipal solid waste (MSW) leachate and the results of limited ex-
perimental work designed to obtain information concerning FML absorption of
volatile organics from dilute aqueous solutions.
The literature reviewed included:
- Analytical data reported in the 1970s on the composition of MSW leach-
ate and more recent data reported in the 1980s to compare the amounts
of chlorinated aromatic and aliphatic organics in currently generated
leachates.
- Results of compatibility testing of FMLs with MSW leachate.
- Partitioning of organics from dilute aqueous solutions to HDPE FMLs
immersed in the solutions.
- Chemistry of dilute regular and related solutions.
Experimental work reported was concerned with the partitioning of methyl
ethyl ketone, toluene, and trichloroethylene from dilute aqueous solutions
containing these organics to FMLs of polyvinyl chloride, linear low-density
polyethylene, chlorinated polyethylene, and chlorosulfonated polyethylene
which were immersed in the solutions.
E. Timothy Oppelt, Director
Risk Reduction Engineering Laboratory
iii
-------
ABSTRACT
This research project consisted of a survey of the open technical
literature relating to the composition of currently produced municipal solid
waste (MSW) leachate, the compatibility of flexible membrane liners (FMLs)
with such leachate, the chemical literature on regular and related solu-
tions, and the results of limited experimental work on the absorption of or-
ganics from dilute aqueous solutions that simulated MSW leachates. A princi-
pal objective, based on past studies, was to assess the'suitability of the
EPA Method 9090 chemical compatibility test to assess the compatibility of
FMLs with MSW leachate in view of the instability of this type of leachate
when removed from a landfill, and the low concentrations of organic con-
stituents in the leachate that are known to be absorbed by FMLs.
The results of the survey revealed the complexity of MSW leachates and
the instability of the leachate on removal from the landfill environment,
which is generally anaerobic. Data on leachate analyses reported before 1980
revealed no information on the presence of priority pollutants or the various
organics that are known to be aggressive to FMLs. Data originating after 1980
included information on the priority pollutants and organics that affect FMLs,
but the concentrations were very low, usually in parts per billion or a few
parts per million. The concentrations of the volatile organic acids and other
products of the degradation of the refuse were higher; however, these species
are not absorbed in significant amounts to have an effect on FMLs. Only one
series of references reported compatibility data on FMLs in contact with MSW
leachates. That research, which was performed in the 1970s, indicated small
to moderate effects on the FMLs which were being produced at that time. No
data were available on currently-produced FMLs based on high-density poly-
ethylene (HDPE).
This survey also indicated that the rules of partitioning of dissolved
organics in dilute aqueous solutions operate so that equilibria are estab-
lished between the organics and the water and the organic and a polymeric
phase (the FML). Partitioning coefficients are established between the
concentrations of organics in the FML and in the water which are relatively
constant over a range of concentrations of organics in the leachate. Solu-
bility parameters of organics and FMLs were reported to be useful in predict-
ing the solubility of organics in FMLs.
Because of uncertainties regarding the compatibility of FMLs and MSW
leachates and the absorption of organics from dilute solutions such as
leachates, limited laboratory experiments were performed to measure the
partitioning of selected organics, i.e., toluene, trichloroethylene, and
methyl ethyl ketone, from dilute aqueous solutions to various types of FMLs,
iv
-------
i.e., chlorinated polyethylene, chlorosulfonated polyethylene, linear low-
density polyethylene, and polyvinyl chloride. The results indicate that,
depending on the similarity of the solubility parameters of the organics and
the FMLs, some of the organics even at comparatively low concentrations can
partition from the water in which they are dissolved to the FMLs. The
partitioning coefficients that were calculated from the data indicate that, at
the very low concentrations in recent analyses of MSW leachate, the effects on
the FMLs would probably not be significant.
Based upon the present data base, it is questionable whether blanket
approval can be given for all FMLs and other geosynthetics for use in the
construction of lining systems for MSW disposal facilities. At the same time
it is also questionable whether EPA Method 9090, as presently performed, will
yield realistic results for judging the compatibility of lining materials with
MSW leachates. Furthermore, EPA Method 9090 may yield misleading results,
considering the instability of MSW leachate and the low concentrations of many
of the organics that have been reported in analyses of currently produced MSW
leachates.
This report was submitted in fulfillment of contract no. 68-03-3413,
work assignment no. 24 by PEI Associates, Inc., under subcontract to Matrecon,
Inc., under the sponsorship of the U.S. Environmental Protection Agency. This
report covers a period from February 1988 to December 1989, and work was
completed as of December 1989.
v
-------
Intentionally Blank Page
-------
CONTENTS
Foreword iii
Abstract vii
Figures ix
Tables x
Abbreviations and Symbols xiii
Metric Conversion Factors xvi
1. Introduction 1
2. Objectives and Approach 3
3. Summary and Conclusions 5
Sumrna ry 5
Observations and conclusions 5
Composition and characteristics of MSW leachates . . 5
Stabilizing MSW leachates 6
Compatibility of FMLs with MSW leachate 6
Threshold concentrations of organics 7
Credibility of results of EPA Method 9090 test 7
Feasibility of performing a reliable compatibility
test 8
4. Recommendations 10
General recommendations 10
EPA Method 9090 test 11
Experimental laboratory research 11
On-site field studies of FML absorption of organics ... 12
5. Survey, Review, and Analysis of Published Information 13
Introduction 13
Characteristics of MSW leachate 14
Composition of leachate analyzed before 1980 .... 14
Composition of MSW leachate reported in 1980s. ... 19
Preservation and stabilization of MSW leachate ... 19
Degradation of constituents in MSW leachates .... 24
Compatibility of FMLs with MSW leachates 25
Results of exposure of the FML specimens 28
Immersion of FMLs in flowing MSW leachate 32
FMLs in dilute aqueous solutions of organics 34
Absorption of dissolved organics from dilute
solutions by polyethylene FMLs 34
Chemical compatibility of FMLs 50
Use of solubility parameters in estimating compatibility. 53
Discussion 62
6. Experimental Work 63
Introduction 63
vi i
-------
Experimental details 63
Immersion test cells 63
Selection of volatile organics 63
Analysis of the dilute aqueous solutions and vapors. 64
Analysis of the organics in FML specimens 67
Analysis and testing of the FMLs selected for this study. 68
Immersion of specimens of FMLs in dilute aqueous solutions . . 68
Immersion of a PVC FML--Experiment 1 68
Immersion of specimens of PVC, LLDPE, CPE, and CSPE-R
Experiment 2 71
Immersion of FMLsExperiment 3 75
Analysis of FMLs used in NSF chemical compatibility study. . . 75
Stability of MSW leachate 80
References & Bibliograpnhy 82
Appendixes
A. Baseline properties of unreinforced FMLs 87
B. Test methods used for determining baseline properties
of unreinforced FMLs 88
C. Effect of long-term immersion of PVC and CPE FMLs
in aqueous solutions of selected organics 89
D. Effect of long-term immersion of HDPE and CSPE-LW
FMLs in aqueous solutions of selected organics 90
vi i i
-------
FIGURES
Figure Page
1 Changes in chemical oxygen demand, turbidity,
color, and conductivity of leachate during
storage at 5ฐC in a capped bottle 20
2 Landfill simulator used to evaluate liner materials
exposed to MSW leachate 26
3 Retention of FML tensile strength as a function of
immersion time in MSW leachate--Butyl rubber, CPE,
CSPE, ELPO, and EPDM FMLs 36
4 Retention of FML tensile strength as a function of
immersion time in MSW 1eachate--EPDM, neoprene,
PB, PEL, LDPE, PVC, and PVC-pitch FMLs 37
5 Concentration as a function of time of absorbed
organics in exposed HDPE FMLs recovered from
Tank I (23ฐC) 47
6 Equilibrium swelling of a crosslinked noncrystalline
polymer and of an uncrosslinked noncrystal1ine
polymer 54
7 Solubility parameters of common solvents and polymers. ... 56
8 Schematic of the immersion test cell 64
9 Calibration curve for toluene, MEK, and TCE in
aqueous solutions 66
10 Calibration curve for toluene, MEK, and TCE in vapor .... 67
ix
-------
TABLES
Tables Pag
1 Parameters for characterizing MSW leachate 15
2 Composition of three MSW landfill leachates 16
3 Characteristics of MSW leachates 17
4 Composition of leachate from different sources as
measured by different researchers 18
5 Composition of MSW leachate showing the effect of
age of the landfil 1 21
6 Priority pollutant organics detected in MSW leachates .... 22
7 Preliminary data on concentrations of organic con-
stituents in leachate from municipal waste landfills. ... 23
8 Tests of FMLs before and after exposure to MSW leachate ... 27
9 Effect on properties of FMLs of 12 and 56 months of
exposure to leachate 29
10 Water and leachate absorption by FMLs 32
11 Analysis of leachate 33
12 Swelling of FMLs on exposure to MSW leachate 33
13 Retention of modulus of FMLs on immersion in
MSW leachate 35
14 Partitioning of dissolved volatile organics from
aqueous solutions to immersed polyethylene FML 38
15 Distribution of nine volatile organics between
saturated aqueous solutions and specimens of a
polyethylene FML 40
16 Distribution of organics between an organic saturated
FML and deionized water 41
x
-------
17 Composition of the spiking mixture 42
18 GC analysis of leachate and FML samples 43
19 Concentration of organics in aqueous solution 44
20 Headspace GC analysis of the exposed FML samples 46
21 Compatibility testing of HDPE FML in deionized water
spiked with 11 organics; 60-mil HDPE FMLUnexposed
and after one, two, three, and four months of
exposure at 23ฐC in Tank 1 48
22 Compatibility testing of HDPE FML in deionized water
spiked with 11 organics; 60-mil HDPE FMLUnexposed
and after one, two, three, and four months, of
exposure at 50ฐC in Tank IV 49
23 Solutions and liquids selected for FML immersion tests. ... 50
24 Effects of immersion in 0.1% solution of DCE
in water 53
25 Solubility parameter values for selected solvents 55
26 Equilibrium volume swelling of the CPE, CSPE, EPDM,
EVA, CR, and PEL FML specimens immersed in 30
different organics and in water 58
27 Equilibrium volume swelling of PB, LDPE, LLDPE, HDPE,
PVC, and PVC-E FML specimens immersed in 30
different organics and in water 59
28 Solubility parameter values for FMLs 60
29 Organics used in absorption experiments with dilute
aqueous solutions 64
30 Gas chromatography conditions for aqueous solution and
vapor analysis 65
31 Properties and methods for testing four FMLs in municipal
solid waste leachate compatibility study 69
32 Analytical and physical properties of unreinforced FMLs ... 70
33 Analytical and physical properties of fabric-reinforced
CSPE FML 71
34 Thermogravimetric analysis of PVC FML after immersion and
headspace GC analysisExperiment 1 72
xi
-------
35 Absorption of organlcs by FMLs immersed .for two months
in dilute aqueous solutions containing a mixture of
organicsExperiment 2 73
36 Headspace analysis of exposed FMLsExperiment 2 76
37 Absorption of organics by FMLs immersed for two weeks
in dilute aqueous solutions containing a mixture of
organicsExperiment 3 77
38 Tensile properties of FMLs after Immersion in dilute
solutions of MEK, TCE, and Toluene in sealed cells-
Experiment 3 79
39 Analysis of FMLs used in NSF chemical compatibility
study 80
xii
-------
ABBREVIATIONS AND SYMBOLS
Ag Silver
AM Amorphous
As Arsenic
ASTM American Society for Testing and Materials
Ba Barium
BOD Biochemical oxygen demand
BOD5 Biochemical oxygen demand (5 days)
C Celsius; Concentration
ca Approximately
Ca Calcium
CaC03 Calcium carbonate
cal Calorie
CASNO Chemical Abstract Services' number
cc Cubic centimeter
CCI4 Carbon tetrachloride
Cd Cadmi urn
CFR Code of Federal Regulations
CH3OH Methyl alcohol
CI Chloride
cm Centimeter
COD Chemical oxygen demand
CPE Chlorinated polyethylene
CR Chloroprene rubber - neoprene
Cr Chromium
CSPE Chlorosulfonated polyethylene
CSPE-LW Chlorosulfonated polyethylene - low water absorption,
i.e. industrial grade
CSPE-R Chlorosulfonated polyethylene - fabric-reinforced
Cu Copper
cu yd Cubic yard
CX Crystalline or semi crystal 1ine thermoplastic
D Dissolved or disintegrated
5 Hildebrand parameter
,5^ Dispersive parameter
ah Hydrogen-bonding parameter
50 Hildebrand solubility parameter
6p Polarity parameter
Total Hansen Solubility parameter
DCE Dichloroethane
DEHP di(ethyl-hexyl) phthalate
DI Deionized
EC Electrical conductivity
xii i
-------
ECO Epichlorohydrin rubber (copolymer of ethylene
oxide and chloromethyl oxirane)
ELPO Elasticized polyolefin
EPA Environmental Protection Agency
EPDM Ethylene propylene rubber
EVA Ethylene vinyl acetate
Fe Iron
FML Flexible membrane liner
FSOT Fused silica open tube
ft Foot
FTKS Federal Test Method Standard
GC Gas chromatography
g Gram
gal Gallon
h Hour
H2 Hydrogen
HpO Water
HC1 Hydrochloric acid
HDPE High-density polyethylene
Hg Mercury
IIR Isobutylene-isoprene rubber (butyl rubber)
in. Inch
K Potassium
L Liter
lb Pound
LDPE Low-density polyethylene
LLDPE Linear low-density polyethylene
yL Microliter
vimho Micromho
MBAS Methylene blue active substances
MDPE Medium density polyethylene
MEK Methyl ethyl ketone
Mg Magnesium
mg Milligram
mil Inch x 0.001
min. minute
mm Millimeter
Mn Manganese
mo Month
MPa Mega pascals
MSk/ Municipal solid waste
MTM Matrecon Test Method
MW Molecular weight
N Nitrogen
N2 Nitrogen
Na Sodium
NaCl Sodium chloride
NBR Nitrile rubber
n.d. No date
Ni Nickel
NSF National Sanitation Foundation
O2 Oxygen
0z Ounce x1v
-------
p
Phosphate
PB
Polybutylene
Pb
Lead
PCB
Polychlorinated biphenyls
PE
Polyethylene
PEL
Polyester elastomer
PP
Polypropylene
PPb
Parts per billion
PPi
Pounds per inch
ppm
Parts per million
psi
Pounds per square inch
PVC
Polyvinyl chloride
R
Fabric-reinforced
S-100
Stress at 100% elongation
S-200
Stress at 200% elongation
Se
Selenium
S04
Sulfate
TBP
Tributyl phosphate
TCA
1, 1, 1-trichloroethane
TCE
Trichloroethylene
TDS
Total dissolved solids
TGA
Thermogravimetric analysis
THF
Tetrahydrofuran
TOC
Total organic carbon
To!
Toluene
TP
Thermoplastic
TS
Total solids
TSS
Total suspended solids
TVA
Total volatile solids
VOA
Volatile organic acids
XL
Crosslinked
Zn
Zi nc
XV
-------
METRIC CONVERSION FACTORS
(U.S. Customary Units to SI Units)
To convert Multiply by
Inches to centimeters (cm) x 2.54
Feet to meters x 0.3048
Mils to centimeters (cm) x 2.54 x 10~3
Mils to millimeters (mm) x 2.54 x 10~2
Pounds per square inch (psi) to megapascals (MPa) x 6.895 x 10~3
Pounds per inch (ppi) to kilonewtons per meter (kN/m) x 1.751 x 10~1
Pounds (force) to Newtons x 4.448
U.S. Customary Units are used in this report as they are commercially
used in the United States in the solid waste industry as well as in the
liner production and installation industries.
xvi
-------
SECTION 1
INTRODUCTION
Under Subtitle "C" of the Resource Conservation and Recovery Act, the EPA
requires that all of the materials used in the construction of waste disposal
facilities which could come in contact with the leachate from the waste being
contained, be tested for chemical resistance to the specific leachate being
generated. Laboratory and pilot-scale studies by Matrecon indicate that
commercially-available FMLs are chemically resistant to municipal solid waste
(MSW) leachate (Haxo et al, 1982). These studies were conducted with leachate
generated in simulators containing freshly collected MSW which had been
shredded. The analyses of that leachate indicated the presence of inorganic
salts and volatile acids with no indication of chlorinated and aromatic
organics. The addition of hazardous waste from small quantity generators and
nonhazardous industrial waste to the MSW stream may result in the generation
of leachate that contains measurable quantities of organic compounds which
could be absorbed by the flexible membrane liners (FMLs) and might adversely
affect some of their properties and possibly render them unserviceable.
Currently-generated MSW leachate from present landfills may not be
completely inactive towards FMLs and other polymeric materials of construc-
tion used in lining systems due to the possible presence of chlorinated and
aromatic organics; constituents of the leachate can affect polymeric compo-
sitions in different ways, depending on their species and concentrations
in the leachate and on the specific polymeric materials. Furthermore, the
effects of the constituents can be synergistic and vary with time as the
concentrations change with the aging of the landfills and the leaching of
the waste. Of particular importance with respect to swelling of the FMLs
are the dissolved organics and their concentrations that may be in the
leachate. Dissolved inorganics are not absorbed by an homogeneous FML nor
do they permeate.
Some organics can cause FMLs to swell and become softer and more perme-
able to other organics. Swelling can simultaneously cause losses in mechani-
cal property values, such as in tensile strength and in tear resistance; thus,
absorption of organics from leachate may result in FMLs becoming more easily
torn and damaged. Water can also cause some FMLs to swell. Compatibility
testing is necessary when the waste liquid or leachate is known to contain
sufficiently high concentrations of constituents that are aggressive to
some types of FML materials or other polymeric materials. Under such cir-
cumstances, it is necessary to determine the compatibility of the candidate
FMLs with a representative sample of the leachate. The current method for
determining chemical resistance of FMLs to waste liquids and leachates is EPA
1
-------
Method 9090. However, this method nay not be suitable for determining FML
resistance to MSW leachate due to the instability of the leachate during the
120-day exposure at the temperatures (23 and 50ฐC) called for 1n the test.
This report describes the results of a survey of the open technical
literature relating to the composition and characteristics of MSW leachate,
compatibility of FMLs with MSW leachate, and the results of limited experi-
mental work designed to explore the partitioning of three organics that
are found in MSW leachate from dilute aqueous solutions to four FMLs. The
three organics were methyl ethyl ketone, trichloroethylene, and toluene.
The four FMLs were based on chlorinated polyethylene (CPE), chlorosulfonated
polyethylene (CSPE), linear low-density polyethylene (LLDPE), and polyvinyl
chloride (PVC).
2
-------
SECTION 2
OBJECTIVES AND APPROACH
The objectives of the work performed on this project were:
- To provide technical assistance to the EPA Office of Solid Waste so
that they can formulate a definite opinion regarding the testing of
the chemical compatibility of FMLs and other materials used in the
construction of liner systems for MSW landfills with actual MSW
leachate.
- To determine whether the data base on the chemical compatibility of
FMLs with MSW leachate is sufficient to warrant approval for com-
mercially-available FMLs and other materials used in the construction
of liner systems without having to perform an EPA Method 9090 test.
- To determine whether there is a threshold of concentration for a
given organic above which compatibility testing of FMLs and MSW leach-
ate would be required; also, to determine the threshold of concentra-
tions of mixtures of organics above which compatibility testing would
be required.
- To review data on the effects of the changing characteristics of MSW
leachate on the properties of the FMLs, which contact them during
long-term exposure.
- To assess the credibility of the data obtained in performing EPA Method
9090 compatibility tests on FMLs and MSW leachate, if it should be
decided that such testing of FMLs with MSW leachate is necessary.
The approach to this work was:
- To search, review, and analyze the published open literature regarding
the composition and characteristics of MSW leachate, particularly the
recent literature.
- To search, review, and analyze the open literature regarding the data
available on the compatibility of commercial FMLs with MSW leachates,
and to assess the sufficiency of the current data base to warrant
blanket approval for commercially-available FMLs for use in liner
systems in MSW landfills.
3
-------
- To review basic physical chemistry of solutions, particularly solutions
of nonelectrolytes, the partitioning of solutes (dissolved organics)
between immiscible phases (FMLs and leachate), and solubility parame-
ters of organics and FMLs.
- To perform limited experiments to meet some of the areas of concern; in
particular, to study a variety of commercial FMLs with respect to the
partitioning of organic constituents from dilute aqueous solutions of
three organics that have been observed in MSW leachate.
4
-------
SECTION 3
SUMMARY AND CONCLUSIONS
SUMMARY
The open literature was reviewed for quantitative data and other in-
formation regarding the composition and characteristics of MSW leachates,
the compatibility of FMLs in MSW leachates, and the feasibility of performing
credible compatibility tests over extended periods of time, e.g. the EPA
Method 9090 compatibility test. The following subjects were reviewed:
- Composition and characteristics of MSW leachates, particularly in-
formation on the more recent leachates that are being generated, to
determine the type and concentration of organics that are known to
swell FMLs.
- Compatibility research and testing of FMLs with MSW leachates.
- Partitioning of dissolved organics in dilute aqueous solutions to
different FMLs.
- Potential use of solubility parameters in predicting the absorption
by different FMLs of different organics from dilute aqueous solutions
and MSW leachates.
Due to the lack of data relating to the absorption by FMLs of dissolved
organics from dilute aqueous solutions of the organics, such as leachates,
limited experiments were performed to measure the partitioning of three
dissolved volatile organics from dilute aqueous solutions to four different
FMLs. Also, baseline data on physical properties were obtained on the four
FMLs for use in experiments designed to assess the effects on the properties
of FMLs immersed in dilute aqueous solutions.
OBSERVATIONS AND CONCLUSIONS
Observations and conclusions that can be drawn from the review of the
data in the literature and the limited experimental results obtained in this
study are presented in this subsection.
Composition and Characteristics of MSW Leachates
- MSW leachate is a highly complex mixture of inorganics, organics, and
bacteriological constituents usually generated in anaerobic environ-
ments in MSW landfills. MSW leachate is generally mildly acidic and
5
-------
most of the organic constituents, particularly the volatile acids, are
biodegradable.
- MSW leachate is highly oxidizable and unstable, and thus subject to
rapid changes in composition on removal from the environment in which
it is generated. Even when cooled and sealed in bottles, the compo-
sition of leachate will change for a limited time (Chian and DeWalle,
1977).
- Some of the more recent analyses of MSW leachates indicate the pres-
ence of priority pollutants and other organic species that may be
absorbed to different degrees by FMLs immersed 1n or in contact with
such leachates. However, the limited amount of available analytical
data on MSW leachates indicate their concentrations to be low, i.e.
in parts per billion, and a few concentrations in several parts per
million. Such concentrations imply that, even with high partitioning
coefficients (the ratio of concentrations at equilibrium of the
organics in the FML over that in the leachate), the more promising
FMLs for use in MSW landfills will probably not swell sufficiently to
adversely affect properties significantly.
- The amount of data in the open literature on the full composition of
MSW leachates generated in recently designed and operating landfills
is limited.
Stabilizing MSW Leachates
Except for the refrigeration and sealing of leachate into glass bottles,
no information was located indicating methods for long-term stabilization
of MSW leachates for possible use in analysis or in compatibility testing
of FMLs, such as an EPA Method 9090 test.
Compatibility of FMLs with MSW Leachate
In a single major laboratory and pilot-scale study of the compatibility
of a wide range of FMLs and other potential lining materials with an MSW
leachate, it was found that the effects of the MSW leachate on FMLs were
moderate and, in most cases, probably only reflected the absorption of water
(Haxo et al, 1982). In that study, the leachate was generated 1n individual
pilot-scale landfill simulators constructed for the study and filled with
residential MSW that had been shredded. A single liner sample of a given
type was placed 1n each of two simulators. Six polymeric FMLs and six other
lining materials were investigated in a total of 24 simulators. The leach-
ate used in the study was generated in each simulator and was analyzed for
total and specific organic acids, chemical oxygen demand, total volatile and
nonvolatile solids, and pH. No analysis was specifically performed for
aromatics, hydrocarbons, chlorinated hydrocarbons, or other priority pol-
lutants. The analyses performed during the exposure time showed that the
parameters peaked at about one year and decreased to about 10% of the peak
values at the termination of the study (at 56 months), which reflected the
leaching of the original MSW by the 25 inches per year of water placed on
6
-------
the cubic yard of MSW in each simulator. The properties of the FMLs showed
maximum effects at one year and then tended to return to original values.
No other study specifically devoted to the compatibility of FMLs with
MSW leachate was located in the open literature.
Threshold Concentrations of Organics in MSW Leachate
The concept of a threshold concentration of an organic in an aqueous
solution was considered. It was assumed that it would be the lowest con-
centration at which, on extended exposure to a given organic or mixture of
organics in a given leachate, the effects on the properties of the FML would
be significant. It was also assumed that maximum absorption and equilibrium
would be reached. The threshold concentration of a given organic in a leach-
ate varies with the organic and the FML and would be controlled by the parti-
tioning coefficient between the FML and the water component of the leachate.
An organic that is dissolved in an aqueous solution, such as in a leach-
ate which is in contact with an FML, would partition until an equilibrium
concentration in the aqueous solution and in the FML is reached. This condi-
tion is similar to a system of two liquid layers made up of two immiscible
phases or slightly miscible components to which is added a third substance
which is soluble to some extent in each. In this situation, the FML and the
aqueous solution are the two immiscible phases in which the dissolved organic
has solubility in both. The amount of the organic that is absorbed by the
FML is determined by the relative solubility of the organic in the water and
the FML until an equilibrium is reached. The organic distributes itself or
"partitions" between the water and the FML until an equilibrium is reached.
The ratio of the concentration of the dissolved organic in the FML over that
of the concentration in the water is the distribution or partitioning coef-
ficient. This coefficient remains relatively constant over a practical con-
centration range, i.e., a low concentration range. These coefficients will
be determined by the solubility parameter pairs, i.e., the organic and the
water, and the organic and the FML. The concentrations of an organic at
equilibrium, though the concentrations can be greatly different in each
phase, are at equal chemical potential. As the concentration of the or-
ganics in the leachate or solution changes, the equilibrium will shift
and result in changes in the concentration in the FML.
It would, therefore, appear that a threshold concentration would be
unique to a given combination of an FML and an organic or a combination of
organics.
Credibility of Results of EPA Method 9090 Test of FMLs with an MSW Leachate
Although EPA Method 9090 is a reliable test for assessing the compati-
bility of FMLs with hazardous wastes, leachates, and waste liquids, this test
presents problems in determining the true compatibility of a given FML with a
given MSW leachate. Based on the current compositional data, the concentra-
tions of the organics in an MSW leachate that would partition, and thus would
be aggressive to polymeric FMLs, are low, i.e., in parts per billion in most
cases and in parts per million in a few. The partitioning of the organics
7
-------
in a leachate to the FML phase would also be comparatively low although the
concentrations in the FML may be several hundred times more than that in the
water. The total absorption by the FML would probably be less than a few
percent, an insufficient amount to significantly affect the properties of the
FML. It should be noted that in almost all cases an absorption of at least
5% of the organics by the FML is required to affect the mechanical properties
of the FML.
The concentration of an organic solute in the FML and that in the water
tends to go to an equilibrium which would mean that there will be a limit on
the concentration that can be absorbed for a given combination of phases;
thus, if the concentration in the aqueous phase (the leachate) decreases,
the organic in the FML will return to the water until equilibrium is again
achieved at a lower concentration.
It is believed that the first step in the consideration of running an
EPA Method 9090 test would be to perform a detailed analysis of the leachate
to determine the organic species and their respective concentrations in the
leachate. Using solubility parameter data, one could estimate the amount
that could be absorbed by an FML. It would be important to analyze the MSW
leachate for the chlorinated hydrocarbons and the aromatic hydrocarbons,
which have solubility parameters close to those of most FMLs. The absence or
low concentrations of these species would indicate that EPA Method 9090 need
not be performed.
Feasibility of Performing a Reliable Compatibility Test
of FMLs with MSW Leachate
An important factor in conducting a chemical compatibility test is that
the concentration of the dissolved constituents in the test leachate reflects
the composition of the leachate in actual service. This means that the
leachate should maintain a constant concentration of those constituents that
might affect the FMLs during extended service. MSW leachate is highly oxi-
dizable and unstable and is subject to change or exposure to air almost
immediately upon removal from the service environment, which generally is
anaerobic. Methods of preserving, stabilizing, or sterilizing MSW leachates
after removal from sumps and drainage systems, which would be suitable to use
in the compatibility testing of FMLs with MSW leachate, were not found in the
literature. Refrigeration has generally been used to protect MSW leachates
from bacteriological changes prior to analysis; however, EPA Method 9090 is
performed at higher temperatures (23 and 50ฐC) which would be compatible with
refrigeration.
Due to the low concentration of most of the organics that would be
contained in the leachate and absorbed by an FML specimen immersed in the
leachate in a chemical compatibility test, it would be necessary to carefully
monitor the concentrations of these organics due to the possible loss by
evaporation or degradation. Under service conditions, the concentrations of
the constituents of the leachate would be comparatively constant or change
gradually. Also, due to the fact that many of the organics in the leachates
8
-------
are highly oxidizable, it would be essential to maintain anaerobic condi-
tions within the exposure cells, or that means be developed for protecting
and stabilizing the leachate to maintain constant concentrations.
Under the present protocol of EPA Method 9090, it is questionable whether
a realistic and meaningful compatibility test of FMLs with MSW leachate can be
performed without modification of equipment to assure anaerobic conditions or
stabilization of the leachates to assure little change in concentrations of
the organic constituents, which can be many in number and very low in amounts.
Because the laws of partitioning operate, the concentrations of the organics
in an FML will vary with the concentration of the respective organics in the
leachate and the swelling of the FML will continually change. Consequetly, as
the landfill ages the leachate changes with time and tends to become less
concentrated.
9
-------
SECTION 4
RECOMMENDATIONS
In light of the uncertainties as to the need for testing FMLs and other
geosynthetics for compatibility with MSW leachate and the uncertainties as to
the meaningfulness of EPA Method 9090 when it is performed with MSW leachate,
a number of recommendations are made to obtain the necessary information to
respond to these uncertainties. These recommendations are in four areas:
- Obtaining additional information on leachates currently generated in
service, from such sources as surveys and accumulated data from permit
applications, etc.
- Improving the performance and meaningfulness of EPA Method 9090 for
use with MSW leachate.
- Experimental laboratory research to develop specific Information.
- On-site field studies of FML absorption of organics from MSW
leachates.
GENERAL RECOMMENDATIONS
The following recommendations relate to obtaining more information
about the leachates currently being generated in newly designed, operating,
and closed landfills for the purpose of establishing the need for performing
a Method 9090 test on candidate materials:
- Obtain more in depth analyses of MSW leachates than have normally been
made to determine the presence of organics that are specifically ag-
gressive to FMLs; these organics include chlorinated solvents, aro-
matic solvents, and some aliphatic solvents.
- Determine by survey and analyses the specific types and amounts of
priority pollutants of MSW leachates for a wide range of sources
around the country.
- Quantify the amounts of nonbiodegradable constituents that may be
found in MSW leachates, e.g. from small quantity generators and
household refuse, and by illegal dumping.
10
-------
- Assess the composition of leachates generated as a function of time
from FML-lined MSW landfills during their active service life and
post-closure care period. It is anticipated that the amount and
concentration of the leachate will diminish with time.
EPA METHOD 9090 TEST
It is recommended that the following tasks be performed to assess and
improve the meaningfulness of EPA Method 9090:
- Analyze leachates to determine the concentrations of organics that are
known to have solubility parameters that match those of the FML under
consideration and thus would partition to the FML. If only acids and
other polar materials show up in the analyses, or are at concentra-
tions less than 10 ppm, the performance of EPA Method 9090 is probably
not necessary for that specific combination of the FML and leachate.
- Request that information such as listed above be included in permit
applications as basic data for determining the need for an EPA 9090
test; obtain data for the total organic carbon, biological oxygen
demand, chemical oxygen demand, pH, and electrical conductivity of the
leachate.
- In performing an EPA Method 9090 test, analyze the leachate at the
beginning of the exposure, during the exposure, and at the end of each
month of exposure to develop information with respect to the con-
centration of organics during the exposure. Also perform headspace
GC analyses of the FML samples removed at the end of each month of
exposure to determine the organics and the amounts of the organics that
were absorbed by the FML.
EXPERIMENTAL LABORATORY RESEARCH
Further experimental laboratory research in the following areas is
recommended:
- Expand the studies relating to the partitioning of dissolved organics
in dilute aqueous solutions or MSW leachates from the aqueous solutions
to an FML which is immersed or in contact with solutions or leachates
containing the organics.
- Investigate dilute aqueous solutions of organics found in MSW leachates
that are known to affect different FMLs to determine the rates of
absorption by the FMLs, the time required to reach equilibrium condi-
tions, and the distribution coefficients. These studies should include
variations in concentration of the organics, different FMLs, different
temperatures, and the effects of the presence of dissolved inorganics,
e.g., salts.
- Investigate mixtures of different organics dissolved in water from
very low concentrations to saturation of the organics in water to
11
-------
determine whether there are additive effects of many organics at low
concentrations.
- Spike actual MSW leachates with different organics which have been
found in MSW leachates to assess the effects of the broad spectrum
of organics on the absorption of specific organics.
- Determine whether the initial concentrations of organics, such as the
aromatics and chlorinated hydrocarbons, remain after degradation of
the organic acid and polar constituents in the leachate has taken
place.
- Investigate the stabilization of MSW leachates by various means in-
cluding sterilization of the leachate to destroy bacterial components,
and develop a protocol for handling MSW leachate after collection for
potential use in compatibility tests.
- Develop a laboratory protocol for assessing compatibility of FMLs with
MSW leachates and perform a sufficient number of tests to define test
conditions and criteria of compatibility; the test method may include
the use of spikes.
ON-SITE FIELD STUDIES OF FML ABSORPTION OF ORGANICS
It is recommend that coupons of various FMLs, geosynthetics, and other
components of liner systems be immersed in sumps of active and closed MSW
landfills. After exposure of different lengths of time, these coupons should
be removed and analyzed first by headspace GC to determine the amount and type
of volatile organics that had been absorbed and then extracted to remove the
extractables which are analyzed by GC to determine the amount and type of
nonvolatile organics that had been absorbed. The results of the analytical
tests on these materials should indicate the organics that may be in leachates
that are aggressive to FMLs over extended periods of time.
12
-------
SECTION 5
SURVEY, REVIEW, AND ANALYSIS OF PUBLISHED INFORMATION REGARDING
THE COMPOSITION OF MSW LEACHATES AND THE COMPATIBILITY OF FMLS
WITH MSW LEACHATES
INTRODUCTION
The information sought in the survey of the scientific and open-technical
literature relating to the compatibility of FMLs with MSW leachates included
the following:
- Data on MSW leachate composition and characteristics, particularly
currently generated leachate.
- Data from the compatibility testing of FMLs with MSW leachates, par-
ticularly any data on tests performed in accordance with EPA Method
9090.
- Information on the preservation and stabilization of MSW leachates,
particularly at temperatures somewhat higher than 23ฐC so that these
leachates can be used in conventional compatibility tests, e.g. EPA
Method 9090.
- Data on the resistance of FMLs and polymeric compositions to dilute
aqueous solutions of organics and inorganics. Such solutions simulate
MSW leachates in many respects.
- Basic information from physical chemistry regarding such factors as
the chemistry of dilute aqueous solutions of organics, solubility
parameters, constituent activity, partitioning of dissolved organics
between phases, and transport of organic species.
- Information on estimates of the amounts of volatiles and other organics
that are disposed of in MSW landfills by small-quantity generators,
households, and by illegal dumping.
- Data on biodegradation of organics in MSW landfills, particularly those
in anaerobic conditions.
The approach taken in performing this survey was as follows:
- Reviewing published data on the composition of MSW leachates.
13
-------
- Searching and reviewing the existing literature regarding the effects
of MSW leachate on four lining materials (i.e. HDPE, LLDPE, PVC, and
CSPE).
- Searching for information regarding the stability of MSW leachate
immediately after it is removed from a leachate drainage system.
The information resulting from this literature search is summarized in the
following subsections.
CHARACTERISTICS OF MSW LEACHATE
Composition of Leachate Analyzed Before 1980
Considerable information is available which deals directly with MSW
leachate composition and characteristics in the 1970s when pollution from MSW
was of principal concern to the EPA; much of this Information is available in
the proceedings of various EPA symposia, reports of research, surveys, and in
the open-technical literature. The data reflect the composition of leachates
generated both in laboratory and pilot-scale projects and in actual full-scale
MSW landfills (Chian and DeWalle, 1976 and 1977; Dunlap et al, 1976; Ham, 1975
and 1976; Ham et al, 1979; Pohland, 1975 and 1976; Pohland et al, 1979 and
1987). These data include analysis for trace metals, organic acids, and many
of the dissolved inorganics, i.e. salts, etc. Much of this information on
leachate composition was considered in developing the chapter on wastes for
the EPA Technical Resource Documents on the lining of waste storage and dis-
posal facilities" (Matrecon, 1983 and 1988). More recent analyses of MSW
leachates have shown the presence of a variety of volatile organics and
priority pollutants many of which can potentially interact with FMLs.
The leachate produced from MSW is a highly complex liquid mixture of
soluble organic, inorganic, ionic, nonionic, bacteriological constituents,
and suspended colloidal solids in a principally aqueous medium. It contains
products of the degradation of organic materials and soluble ions which may
present a pollution problem to surface and ground waters (Phillips and Wells,
1974). The quality of the leachate depends on the composition of the waste
and the combined physical, chemical, and biological activities.
The precise composition of leachate is waste- and site-specific, depend-
ing on such variables as type of waste, amount of infiltrating water, age of
landfill, and pH. Table 1 lists parameters of leachate which are used as
analytical indicators of landfill leachate in the groundwater near a landfill.
The organic parameters and their magnitudes are of particular importance in
assessing liner compatibility. Tables 2 and 3 present data to show the
complexity in the composition of actual leachate from MSW, its site-specific
character, and its variation with time.
As reported in the literature, the compositions of leachate samples from
different MSW landfills show large variations in dissolved species and their
concentrations. Table 4 summarizes the ranges of leachate composition; these
data show that the age of the landfill or leachate generator, and thus the
14
-------
TABLE 1. PARAMETERS FOR CHARACTERIZING M.SW LEACHATE
Chemical
Physical
Organic
Inorganic
Biological
Appearance
Chemical oxygen demand (COD)
Total bicarbonate
Biochemical oxygen
PH
Total organic carbon (TOC)
Solids (TSS, TDS)
demand (BOD)
Oxidation-reduction
Volatile organic acids (VOA)
Volatile solids
Coliform bacteria
potential
Organic nitrogen
Chloride
(total, fecal;
Electric conductivity
Phenols
Phosphate/phosphorus
fecal streptococcus)
Color
Tannins, lignins
Cyanide
Standard plate count
Turbidity
Ether soluble (oil and grease)
Fluoride
Temperature
Methylene blue active
Sulfate
Odor
substance (MBAS)
Alkalinity and acidity
Organic functional groups
Hardness
as required
Nitrate-N
Chlorinated hydrocarbons
Nitrite-N
Priority pollutants
Ammonia-N
Calcium
Magnesium
Hardness
Heavy metals (Pb, Cu,
Ni, Cr, Zn, Cd, Fe,
Mn, Hg, As, Se, Ba,
Ag)
Source: Appendix A of Matrecon (1988) taken from EPA (1977).
-------
TABLE 2. COMPOSITION OF THREE MSW LANDFILL LEACHATES
Concentration of Constituents (ng/L), except pH and Electrical Conductivity
Constituent
Wi gh
(1979)
Source of data
Breland
(1972)
Griffin
and Shirnp
(1978)
bod5
13,400
COD
42,000
18,100
1,340
TOC
5,000
m
Total solids
36,250
12,500
Volatile suspended solids
ซ ~
76
Total suspended solids
ซ
85
9
Total volatile acids as acetic acid
9,300
333
Acetic acid
ซ ซ
5,160
Propionic acid
ซ
2,840
Butyric acid
ซ
1,830
Valeric acid
1,000
~
Organic nitrogen as N
ซ ซ
107
ซ ป
Ammonia nitrogen as N
950
117
862
Kjeldahl nitrogen as N
1,240
ill
pH
6.2
5.1
6.9
Electrical conductivity (umho/cm)
16,000
~
Total alkalinity as CaC03
8,965
2,480
ป ft
Total acidity as CaC03
5,060
3,460
Total hardness as CaC03
6,700
5,555
Chemicals and metals:
Arsenic
0.11
Boron
29.9
Cadmium
1.95
Calcium
2,300
1,250
354.1
Chloride
2,260
180
1.95
Chromium
<0.1
Copper
ซ ซ
<0.1
Iron
1,185
185
4.2
Lead
t ฆ
4.46
Magnesi um
410
260
233
Manganese
58
18
0.04
Mercury
0.008
Nickel
0.3
Phosphate
82
1.3
Potassium
1,890
500
Si 1ica
14.9
Sodi um
1,375
160
748
Sulfate
1,280
<0.01
Zinc
67
ซ i
18.8
Source: Appendix A of Matrecon (1988).
16
-------
TABLE 3. CHARACTERISTICS OF MSW LEACHATES3
Constituent
Reference*5
(mg/L)
Reference0
(mg/L)
Reference^
(mg/L)
Referencee
(mg/L)
Reference^
Fresh Old
B0D5
9-54,610
7,500-10,000
14,950
COD
0-89,520
100-51,000
16,000-22,000
500-1,000
22,650
81
Total dissolved solids
0-42,276
10,000-14,000
12,620
1,144
Total suspended solids
6-2,685
100-700
327
266
Total nitrogen
0-1,416
20-500
989
7.51
PH
3.7-8.5
4.0-8.5
5.2-6.4
6.3-7.0
5.2
7.3
Electrical conductivity
(pmho/cm)
6,000-9,000
1,200-3,700
9,200
1,400
Total alkalinity as
CaC03
0-20,850
800-4,000
630-1,730
Total hardness as CaC03
0-20,800
200-5,250
3,500-5,000
390-800
Chemicals and Metals:
Cadimum (Cd)
0.4
Calcium (Ca)
5-4,080
900-1,700
111-245
2,136
254
Chloride (CI)
34-2,800
100-2,400
600-800
100-400
742
197
Copper (Cu)
0-9.9
0.5
<0.04-0.11
0.5
0.1
Iron (Fe)
0.2-5,500
200-1,700
210-325
20-60
500
1.5
Lead (Pb)
0-5.0
1.6
Magnesium (Mg) 16
.5-15,600
160-250
22-62
277
81
Manganese (Mn)
0.6-1,400
75-125
1.02-1.25
49
Phosphate (P)
0-154
5-130
21-46
7.35
4.96
Potassium (K)
2.8-3,770
295-310
107-242
Sodium (Na)
0-7,700
100-3,800
450-500
106-357
Sulfate (SO4)
1-1,826
25-500
400-650
13-84
Zinc (Zn)
0-1,000
1-135
10-30
<0.04-0.47
45
0.16
aEPA (1975). bEPA (1973).
^Brunner and Carnes (1974)
Source: Matrecon (1988).
cSteiner
et al (1971).
dGenetelli and Cirello (1976).
eHam (1975).
-------
TABLE 4. COMPOSITION OF LEACHATE FROM DIFFERENT SOURCES AS MEASURED BY DIFFERENT RESEARCHERS
Source
SHWRL (1973)
Fungaroli (1971)
Drexel University
Reinhart and
Merz
(1974)
Riverside
Sonoma County (1973)
Pohland
(1972)
Georgia
Inst. Tech.
Range
of values
fron the
Parameter8
Cincinnati
Ham (1973)
B-l
Control
Reci rculated
literature''
Age of landfill, year
1
2
3.5
1.5
2
2
3
.
COD
16,000-22,000
1,000-51,000
2,700-10,650
3,260-22,400
22,700-89,520
4,320-12,000
40-89,520
bod5
7,500-10,000
...
1,550-8,450
81-33,100
2,250-19,200
15,500-33,600
2,500-11,000
81-33,360
T0C
...
...
1,230-5,000
256-28,000
pH, units
5.2-6.4
3.7-8.5
5.9-8.1
5.6-7.6
4.7-5.4
4.6-6.5
5.2-5.6
3.7-8.5
TS
10,000-14,000
0-42,000
4,028-7,790
ฆ
2,442-12,500
0-59,200
TDS
10,000-14,000
.
724-14,080
14,600-21,010
584-44,900
TSS
100-700
10-26,500
.
16-200
22-600
34-610
10-700
Specific conductance,
umhos/cm
6,000-9,000
...
...
...
2,810-16,800
Alkalinity as CaC03
800-4,000
0-9,700
1,800
730-9,500
240-3,920
1,680-7,900
558-2,800
0-20,850
Hardness as CaC03
3,500-5,000
0-5,500
1,400
650-8,120
450-1,940
0-22,800
Total phosphorus
25-35
0-130
12
0.2-29
0-2.8
1.4-79.2
2.8-26
0-130
Ortho phosphorus
23-33
ฆ
...
...
6.5-85
Nitrogen as NH4
0-482
0.2-890
0-81
880-194
56-187
0-1,106
Nitrogen as NO3 + NO2
0.2-0.8
...
...
0-0.90
0-4.7a
...
0.2-10.29
Calcium
900-1,700
80
115-2,570
20-1,082
561-1,800
125-750
60-7,200
Chloride
600-800
4.7-2,340
400
96-2,350
56-490
920-1,565
98-385
4.7-2,467
Sodium
450-500
0-7,700
85-1,860
80-338
408-1,010
64-143
0-7,700
Potassium
295-310
28-1,860
48-148
260-910
28-3,770
Sulfate
400-650
25-450
20-250
257-1,040
81-156
1-1,558
Manganese
75-125
20
...
3-10
0.09-125
Magnesium
160-250
64-410
2.6-608
316-672
26-75
17-15,600
Iron
210-325
0-1,716
330
6.5-305
22-1,050
165-300
9-95
0-2,820
Zinc
10-30
0-167
5.5
0.23-9.0
85-85
...
0-370
Copper
0.9-9
*
...
0.2-0.44
<0.2-0.4
...
0-9.9
Cadimum
...
0
<0.05-0.16
...
0.03-17
Lead
...
...
<0.5-1.81
<0.0-2.0
...
<0.10-2.0
aAll values reported in mg/L, except specific conductance in umhos/cm and pH in units.
bSee also Garland and Mosher (1975) and Table 2 of Griffin and Shimp (1978).
Source: Chian and DeWalle (1977).
-------
degree of solid waste stabilization, has a significant effect on the com-
position of leachate. Other factors that contribute to the variation of
data are solid waste characteristics (e.g., the composition and size of the
waste and degree of compaction), the moisture content and degree of rainwater
infiltration, temperature, sampling technique, and analytical methods. Other
factors such as landfill geometry and interaction of leachate with its en-
vironment prior to sample collection also contribute to the spread of data.
Most of these factors are rarely defined in the literature, making interpre-
tation and comparison with other studies difficult, if not rather arbitrary.
Some data are available on the effects the time lapse between sample
collection and analysis and the age of the landfill from which the leachate
is collected can have on leachate composition. Figure 1 illustrates the
changes that take place in chemical oxygen demand (COD), turbidity, electrical
conductivity (EC), and color irranediately after the collection of a leachate,
even after it has been placed in storage in a capped bottle at 5ฐC. For in-
stance, at the time of withdrawal of the leachate from the anaerobic environ-
ment, its color is often a transparent light yellow to light green, but on
contact with air; it immediately darkens and constituents begin precipitating.
The effect of the age of the landfill on the composition of the leachate
is illustrated by the data presented in Table 5. The data show that the
concentration of many constituents, both organic and inorganic, are lower for
leachate generated in older landfills. It should be recognized that the
leachates were taken from landfills that were operating in the 1960s and
1970s.
Composition of MSW Leachate Reported in the 1980s
In more recently published information, data show the presence of vol-
atile organics in MSW leachate. Tables 6 and 7 present concentration ranges
for priority pollutants and volatile organics in MSW leachates. Many of the
constituents can be absorbed by FMLs from the leachate; however, the con-
centrations in the aqueous leachate of most are low and, even if they parti-
tion to the FMLs, the amounts may not be sufficiently large to cause signifi-
cant changes in properties of the FMLs, even in long exposures. For instance,
the data in Table 6 show the maximum concentrations to be 20,000 ppb, i.e. 200
ppm, which would result in less than 1% swell for most FMLs. The maximum con-
centrations shown in Table 7 are 28,000 and 28,800 ppb for MEK and 2-propanol,
respectively, both of which at those concentrations would swell most FMLs only
a fraction of a percent.
Preservation and Stabilization of MSW leachate
When removed from a normal service environment, usually anaerobic, an
MSW leachate must immediately be protected to prevent changes in composition
before it is analyzed. At the time of removal from the landfill environment,
an MSW leachate is usually light colored and clear, but due to its generally
high chemical and biological oxygen demand, it immediately begins to absorb
oxygen and will quickly precipitate brown to black organic solids which fall
to the bottom of the container; also, the liquid darkens.
19
-------
50
3
H
-ป
40
ฆu
2
ป- 30
20
10
-50,000
s
U E
25,000-
z
Turbidity
Conductivity
0.3 o -0.9 8
100 1000
Time, mln.
10000
Figure 1. Changes in chemical oxygen demand, turbidity, color, and conductivity
of leachate during storage at 5ฐC in a capped bottle. (Source: Chian
and DeWalle, 1977).
-------
TABLE 5. COMPOSITION OF MSW LEACHATE SHOWING
THE EFFECT OF AGE OF THE LANDFILL
Landfil1
Dupage
Dupage
Dupage
Dupage
Parameter3
LW-6B
MM-6 3
MM-61
LW-6B
Age of landfill, years
5.5
8.5
14.5
16.0
COD
8,000
2,940
360
40
BOD5
14,000b
4,560b
125b
225b
TOC
pH, units
6.3
7.0
TS
ซ
TDS
6,794
5,910
1,104
1,198
TSS
Specific conductance, pmhos/cm
~
ซ
Alkalinity as CaC03
5,810
4,720
1,630
2,250
Hardness as CaC03
2,200c
2,500c
690c
540c
Total Phosphorus
1.2
0.17
0.5
8.9
Ortho-Phosphorus
ฆ
Nitrogen as NH4
ป
Nitrogen as NO3 + NO2
0.7d
0.5d
0.14d
1.6d
Calcium
308
447
156
102
Chloride
1,330
946
205
135
Sodium
810
615
63
74
Potassium
610
220
85
100
Sulfate
2
1
1
2
Maganese
0.06
0.09
0.24
0.06
Magnesium
450
725
110
90
Iron
6.3
12
106
0.6
Zinc
0.4
0.05
0.10
4.5
Copper
<0.5
<0.5
<0.5
<0.5
Cadimum
<0.05
<0.05
<0.05
<0.05
Lead
0.5
1.0
1.0
1.0
aAll values reported in mg/L, except specific conductance in ymhos/cm and pH
in units.
bBased on 20-day BOD.
cBlackwell's value calculated from Mg and Ca concentrations.
dUsing only NO3 analysis; NO2 not determined.
Source: Hughes et al (1971).
21
-------
TABLE 6. PRIORITY POLLUTANT ORGAN1CS DETECTED IN NSW LEACHATES
Parameter3
Ratio of number
of samples above
detection limits/
number analyzed
For sites where detected
Range, ppb Median, ppb
Acid orqanics (11)
Phenol
4-Nitrophenol
Pentachlorophenol
Volatile organics {32)
Dibutyl phthalate
Nitrobenzene
Isophorone
Dimethyl phthalate
Butyl benzyl phthalate
Naphthalene
Chlorinated pesticides (19)
Delta-BHC
PCBs (7)
PCB-10I6
3b/5
1/5
1/6
2b/5
l/b
2b/5
2/5
lb/5
1/5
1/5
221-5,790
17
3
12-150
40-120
4,000-16,000
30-55
125-150
19
4.6
2.8
293
Methylene chloride
6/6
106-20,000
2,650
Toluene
5/5
280-1,600
420
1,1-Dichloroethane
3/5
510-6,300
570
Trans 1,2-dichloroethene
3/5
96-2,200
1,300
Ethyl benzene
2/5
100-250
150
Chloroform
3b/6
14.8-1,300
71
1,2-Dichloroethane
2b/5
13-11,000
Trichloroethene
2/5
16C-600
Tetrachloroethene
2b/5
26/60
Chloromethane
1/5
170
Bromomethane
1/5
170
Vinyl chloride
lb/5
61
Chloroethane
1/5
170
Trichlorofluoromethane
lb/5
15
1,1,1-Trichloroethane
1/5
2,400
1,2-Dichloropropane
lb/5
54
1,1,2-Trichloroethane
1/5
500
Ci s-1,3-Dichloropropene
lb/5
18
Benzene
lb/5
19
1,1,2,2,-Tetrachloroethane
1/5
210
Acrolein
1/5
270
Dichlorodifluoromethane
1/5
180
Bi s(chloromethyl)ether
1/5
250
Base neutral organlcs (46)
Bis(2-ethyl hexyl)phthalate
5b/5
34-150
110
Diethyl phthalate
4b/5
43-300
175
100
^Number in parentheses represents total number of compounds analyzed in
category.
^Includes suspect value near detection limit.
Source: Table 3 of Kmet and McGinley (1982).
22
-------
TABLE 7. PRELIMINARY DATA ON CONCENTRATIONS OF ORGANIC
CONSTITUENTS IN LEACHATE FROM MUNICIPAL WASTE LANDFILLS
(Units in ppb)a
Constituent
Minimum
Maximum
Median
Acetone
140
11,000
7,500
Benzene
2
410
17
Bromomethane
10
170
55
1-Butanol
50
360
220
Carbon tetrachloride
2
398
10
Chlorobenzene
2
237
10
Chloroethane
5
170
7.5
Bis(2-chloroethoxy)methane
2
14
10
Chloroform
2
1,300
10
Chloromethane
10
170
55
Delta BHC
0
5
0
Dibromomethane
5
25
10
1,4-Dichlorobenzene
2
20
7.7
Dichlorodif1uoromethane
10
369
95
1,1-Dichloroethane
2
6,300
65.5
1,2-Dichloroethane
0
11,000
7.5
Cis 1,2-dichloroethene
4
190
97
Trans 1,2-dichloroethene
4
1,300
10
Dichloromethane
2
3,300
230
1,2-Dichloropropane
2
100
10
Diethyl phthalate
2
45
31.5
Dimethyl phthalate
4
55
15
Di-n-butyl phthalate
4
12
10
Endrin
0
1
0.1
Ethyl acetate
5
50
42
Ethyl benzene
5
580
38
Bis(2-ethyl hexyl )phthalate
6
110
22
Isophorene
10
85
10
Methyl ethyl ketone
110
28,000
8,300
Methyl isobutyl ketone
10
660
270
Naphthalene
4
19
8
Nitrobenzene
2
40
15
4-N1trophenol
17
40
25
Pentachlorophenol
3
25
3
Phenol
10
28,800
257
2-Propanol
94
10,000
6,900
1,1,2,2-Tetrachloroethane
7
210
20
Tetrachloroethene
2
100
40
Tetrahydrofuran
5
260
18
Toluene
2
1,600
166
Toxaphene
0
5
1
1,1,1-Trichloroethane
0
2,400
10
I,l,2-Tr1chloroethane
2
500
10
Trichloroethene
1
43
3.5
Trichlorof1uoromethane
4
100
12.5
Vinyl chloride
0
100
10
m-Xylene
21
79
26
p-Xylene and o-Xylene
12
50
18
aThis table was provided by U.S. EPA, Office of Waste, Economic Analysis
Branch. It includes data from 15 municipal landfill case studies per-
formed by OSW (1986a); data from landfill leachate sampling studies per-
formed by Wisconsin and Minnesota; and data from NPDES discharge permits
for leachates from landfills in New Jersey. These studies provided reli-
able data, albeit on a relatively small number of facilities.
Source: EPA (1986b).
23
-------
In sampling an MSW leachate for analysis, it is necessary after col-
lection to Immediately cool the sample and store it at +5ฐC temperature. The
EPA Method 9090 compatibility test is performed at temperatures above the
+5ฐC, e.g. 23 and 50ฐC, at which considerable biological activity can occur
resulting in continuous changes in properties. If a Method 9090-type test
is run, it is necessary to stabilize the leachate, at least chemically, to
maintain the composition at which it was originally collected in order that a
realistic compatibility test can be run which reflects conditions in service.
The objective is to maintain in the exposure test the in-service conditions
as much as possible.
The literature was reviewed without success to locate references pertain-
ing to the stabilization of MSW leachate over extended periods of time at 23ฐ
and 50ฐC. The literature dealt more with the handling and preservation of the
leachate prior to analysis (Chian and DeWalle, 1977), but nothing was found
for long-term stabilization at ambient and higher temperatures. Chian and
DeWalle (1977) point out the changes that can occur even at 5ฐC. In CFR,
Part 257, (EPA, 1985), several processes are suggested to reduce pathogens
in sludges by sterilization by such means as beta and gairona radiation and
by pasteurization for 30 minutes at 70ฐC. Such means might be applicable to
leachate prior to use in a long-term compatibility test, such as the EPA
Method 9090, to maintain the original composition of the leachate.
To minimize changes in the concentration of the leachate and to simulate
in situ leachate, Haxo et al (1982) used a continuous flow of MSW leachate
7rom landfill simulators in performing immersion testing of FMLs as described
in Section 5.3. The composition of the leachate that was used in these ex-
periments, however, did change with time due to continual leaching at a given
amount of MSW, as has been observed with leachates from older landfills.
It would appear that, if the EPA Method 9090 test of FMLs in MSW leach-
ates were to be required by regulating agencies, additional experimentation
is desirable to assess various means of stabilizing the leachate and the
determining impact upon the compatibility test. Such stabilization might
include acidification, the use of formaldehyde, various bactericides, or
possibly anti-microbial agents, e.g. Parabens for foods.
Degradation of Constituents in MSW Leachates
Many of the constituents of an MSW leachate are readily oxidizable, such
as the higher organic acids and some of the hydrocarbons. On the other hand,
many of the volatile organics, such as the chlorinated organics, are more
refractory and will resist degradation over considerable periods of time,
even at the higher temperatures. These latter organics are generally more
aggressive toward FMLs and may remain in a leachate after the other constit-
uents are degraded. Thus, in laboratory-type exposure and immersion tests,
aggressive organics would remain in the leachate and could be absorbed and
damage the FML.
24
-------
Compatibility of FMLs with MSW Leachate
A search of the open literature indicated that the only reference avail-
able on direct investigations of the effects of exposure to MSW leachate on
FMLs was performed by Matrecon on an EPA contract to assess the compatibil-
ity of a variety of potential lining materials for MSW landfills with an MSW
leachate (Haxo et al, 1982; Matrecon, 1983 and 1988). The materials included
FMLs, asphaltic membranes, asphaltic concrete, and other admix materials.
That study involved three major types of exposure of FMLs to the same type of
leachate:
- Twelve liner materials, six of which were FMLs, were sealed in the
bases of landfill simulators below 8 ft of shredded MSW refuse and 1 ft
of leachate. A sample of each liner material was sealed in two simu-
lators so that the effects of one-sided exposure could be assessed
after two exposure periods, i.e. 12 and 56 months.
- Strips of individual FMLs were buried in the sand layer above the
FML samples sealed in the bases of the landfill simulators. During
exposure they were totally immersed in the leachate.
- FML samples were subjected to immersion tests in moving leachate that
had been generated in the landfill simulators, collected, and pumped
continuously through the cells holding the samples. Samples of the
FMLs were tested after 8, 19, and 31 months of immersion.
Note: No specific immersion tests that closely approximate EPA Method
9090 were conducted, since the work was part of an exploratory
research program performed before EPA Method 9090 was developed.
All exposure testing was performed at 23ฐC or less with leachate that was
continually being generated in landfill simulators constructed and operated
specifically for the project (Haxo et al, 1982). Complete analyses of the
leachate were not performed, though several parameters, i.e. solids, pH, COD,
and total volatile acids (TVA), were monitored.
In the first type of exposure, 2-ft diameter specimens were placed under
8 ft of shredded MSW refuse in landfill simulators. An individual simulator
consisted of a 2-ft diameter steel pipe, 10 feet in height, placed on an
epoxy-coated concrete base (Figure 2). The six FMLs that were exposed as
primary liners in the simulators were:
- Butyl rubber.
- Chlorinated polyethylene (CPE).
- Chlorosulfonated polyethylene (CSPE).
- Ethylene propylene rubber (EPDM).
- Polyvinyl chloride (PVC).
- Low-density polyethylene (LDPE).
25
-------
The butyl rubber and the EPDM FMLs were vulcanized rubbers; the LDPE FML was
a thermoplastic semicrystal11ne polymer, and the remaining three FMLs were
thermoplastic polymers.
%" DRAIN ROCK 3" THICK
GAUGE
SOIL COVER
1% FT. THICK
POLYETHYLENE PIPE LINER
SPIRAL-WELD PIPE
2 FT. DIA. x 10 FT. HIGH
SHREDDED REFUSE
FLANGE AND GASKET
MASTIC SEAL
LINER SPECIMEN
CONCRETE BASE
SAND
SEALING RING
DRAIN ABOVE LINER
GRAVEL
DRAIN BELOW LINER
Figure 2. Landfill simulator used to evaluate liner materials exposed to
MSW leachate. Source: Haxo et al (1982).
Each liner exposure specimen was sealed in the base of the simulator with
epoxy resin to prevent by-passing of the specimen by the leachate. In order
to assess the effects of the MSW on seam durability, a seam was incorporated
through the center of each specimen. The seam was made either by the FML
manufacturer or supplier, or by Matrecon in accordance with the standard
practice recommended by the supplier. Approximately 1 cu yd of shredded
refuse was compacted above each specimen in approximately 4-in. lifts to yield
a density of 1,240 lbs per cu yd at a 30 percent water content. The refuse
26
-------
was covered with 2 ft of soil and 4 in. of crushed rock. Two simulators were
set up for each type of FML and the other 6 liner materials for a total of 24
simulators. One set of 12 simulators was dismantled at the end of 12 months,
and the second set of 12 was dismantled after 56 months.
To generate the leachate, tap water was introduced into each of the
simulators at the rate of 25-in. per year. The leachate generated in each
cell was ponded above the specimen at a 1-ft head by continually draining it
into a collection bag. Any leachate which seeped through the liner was col-
lected in a polybutylene bag below the liner.
In addition to the primary exposure specimens, 2.5 x 22-in. strip speci-
mens of the same and additional FMLs were buried in the sand above the liner
and were thus totally immersed in the leachate. Seams based on different
adhesive systems were incorporated in most of the strips.
Immersion testing of the FMLs was performed outside the simulators by
slowly pumping leachate through cells in which 8 x 10-in. specimens of the
FMLs were hung. The specimens that were removed from the simulators and from
the immersion cells were subjected to a range of physical tests normally per-
formed on rubber and plastic materials to assess the effects of the exposure
on the respective FMLs. The tests that were performed on unexposed and
exposed specimens are listed in Table 8.
TABLE 8. TESTS OF FMLS BEFORE AND
AFTER EXPOSURE TO MSW LEACHATE
Thickness (ASTM D412 and D638)
Tensile strength and elongation at break (ASTM D412)
Hardness (ASTM D2240)
Tear strength (ASTM D624, Die C)
Water absorption or extraction at room temperature and 70ฐC
(ASTM D570)
Seam strength, in peel and in shear (ASTM D413 and D638)
Puncture resistance (Federal Test Method Standard No. 101C,
Method 2065)
Specific gravity (ASTM D792)
Ash (ASTM D297)
Volatiles (MTM-l)a
Extractables (MTM-2)a
aAppendixes G and E from Matrecon (1988).
27
-------
Results of Exposure of the FML Specimens to NSW Leachate
None of the FML specimens that had been well sealed into the bases of
the simulators showed any seepage. The epoxy seals in three of the bases
containing FML specimens cracked and partially disintegrated during the last
year of operation of the simulators, as evidenced by the appearance of leach-
ate below the liner. The damage was confirmed when the simulators were dis-
mantled, and was probably due to off-ratio mix of the components of the epoxy
resin. The absence of seepage under 1 ft of hydraulic head through those
FMLs, the seals of which remained intact, confirms the very low permeability
of the FMLs. The results also showed that the seams that were incorporated
in the liner specimens remained water-tight. When the cells were dismantled,
the exposed liner specimens were cut from the bases while they were still wet
and sealed in polyethylene bags to keep them in a moist condition until they
were tested.
The results of the analyses and physical testing of the specimens before
and after exposure are presented in Table 9. All tests on exposed specimens
were made as soon as possible after removal from exposure. This procedure
reflects as closely as possible the properties of the FML compositions as
they existed in the actual service environment.
The amounts of leachate absorbed by the FMLs were estimated from the
volatiles content of specimens of the exposed FMLs. MSW leachates, as they
are primarily water, are essentially volatile, except for minor amounts of
inorganic dissolved salts. The EPDM, CPE, and CSPE FMLs, in this order, were
found to have increasing volatile contents; therefore, they absorbed the
greater amounts of leachate components. The LDPE, PVC, and butyl FMLs had
lower volatile contents and absorbed lesser amounts of leachate.
By comparing the amounts of extractable constituents in exposed speci-
mens after drying, the amount of plasticizer or other ingredients in the com-
pound that were lost to the leachate can be calculated. In all cases, after
56 months the extractables were lower than the original extractables. The
magnitude of the loss, even in the case of the EPDM and PVC, was in the order
of 10%.
The tensile properties of the FMLs varied; the tensile strength at break
ranged from approximately 1400 to 2500 psi. The changes with exposure time
were only modest and many may have been within experimental error, though
several showed trends toward increasing values. Tests which reflect the
stiffness of the FMLs, such as modulus, stress at 200% elongation, and hard-
ness, showed a minimum at 12 months. These minima may reflect the changes
in the composition of the leachate; at 12 months the leachate concentration
showed significantly higher organics content than it did at 56 months. In
all cases, tear strength and puncture resistance remained at satisfactory
levels over the 56 months of exposure.
Though the FMLs showed good retention of properties during exposure, in
several cases there were significant drops in the strength of the seams of the
CPE, CSPE, and EPDM specimens. The differences reflect different adhesive
28
-------
TABLE 9. EFFECT ON PROPERTIES OF FMLS OF 12 AND 56 MONTHS OF EXPOSURE TO LEACHATE IN MSW LANDFILL SIMULATORS
Item
Test method
Exposure
time, months
Butyl
rubber
CPE
CSPE
EPDM
LDPE
PVC
ro
io
Type of compound3
Liner number^
Analytical properties
Volatiles (2 h at 105ฐC), X
Extractables after removal
of volatiles, X
Solventc
Physical properties
Thickness, mils
Tensile strength^, psi
Elongation at breakd
Stress at 200Xd, psi
ASTI1 D3421,
modified
ASTM 0412
ASTM D412
ASTM D412
Tear strength (Die C)d, ppi ASTM D624
Hardness, Durometer points, ASTI1 P2240
10 second reading
0
12
56
0
56
0
12
56
0
12
56
0
12
56
0
12
56
0
12
56
0
12
56
XL
7
2.02
2.37
11.0
9.8
MEK
63
64
64
1435
1395
1465
400
410
405
695
685
750
175
200
185
51A
50.5 A
51A
TP
12
0.10
6.84
7.61
7.5
5.1
n-heptane
32
35
37
2275
1810
1960
410
400
385
1330
1090
1140
255
320
170
77A
65.5A
70 A
TP
6R
0.29
12.78
13.90
3.8
3.4
acetone
36
38
37
1765
1640
2110
250
300
235
1525
1245
1825
79A
64A
70 A
XL
16
0.50
5.54
5.74
31.8
28.3
MEK
51
51
49
1480
1455
1460
415
435
375
755
740
800
180
195
130
54A
51.5A
51A
CX
21
0.00
0.02
1.95
3.37
MEK
12
11
10
2145
2465
2585
505
505
540
1260
1205
1325
390
495
405
TP
17
0.09
3.55
2.08
37.3
34.4
CC14+
CII3OH
21
21
22
2580
2350
2740
280
330
340
1965
1550
1810
335
450
285
76A
64A
70A
cont inued.
-------
TA8LE 9 (Continued)
Exposure Butyl
Iten Test method time, months rubber CPE CSPE EPDN LDPE PVC
Seam strength
Puncture resistance^ FTMS 101C,
Method 2065
Stress, lb
0
44.8
47.0
32.9
39.4
13.9
25.8
12
49.5
49.8
57.0
40.1
14.8
30.1
56
50.0
51.8
58.2
41.5
17.1
31.3
Elongation, 1n.
0
1.22
1.04
0.60
1.44
0.76
0.69
12
1.20
0.98
0.88
1.18
0.80
0.70
56
1.25
0.98
0.86
1.19
1.24
0.84
Location of seam preparation
...
Lab
Lab
Lab
Factory
Lab
Factory
8ond1ng system
...
Adhesive
Solvent
Cement
Adhesive
Heat
Cenent
(LVT)9
THF:Toluene
(LVT)9
50:50
Peel strength, avg, pp1
0
3.8
10.0
>30.Ch
5.4
>15.6h.'
4.0
12
2.9
5.2
3.4
2.0
5.1
56
3.4
2.9
1.8
7.1
>12.0
5.6
Shear strength, pp1
0
30.0
>57.0h
>50.0h
44.5
>20.2h
>2.72
12
42.0
>35.0
40.2
24.3
> 11.4h ปJ
>25.6h
56
17.0
17.0
10.0
18.0
11
22h
aXL = crossllnked; TP * thermoplastic; CX = semicrystal1ine thermoplastic.
bf!atrecon Identification number. R indicates Uner was fabric-reinforced.
cSolvents used In extraction: HEK = methyl ethyl ketone, CCI4+CH3OH = 2:1 blend of carbon tetrachloride and methyl alcohol.
^Average of values In machine and transverse directions.
eTest method not applicable to fabric-reinforced materials.
^Rate of penetration of probe: 20 Inches per minute.
9Low temperature curing cement.
hBreak 1n specimen outside of seam.
'Seam failed at Initial peak.
JSeam In the polyethylene liner used in the steel pipes; tabs In the liner specimens mounted in base were too short.
-------
systems that were tried. The losses of adhesion did not result in any seep-
age or leakage of the FML specimens.
Overall, the changes in the physical properties of the FKLs resulting
from 56 months of exposure were relatively minor. All of the FMLs softened to
varying degrees during the first 12 months. The changes were probably due to
the swelling by the leachate. Between 12 and 56 months, the PVC, CSPE, and
CPE FMLs hardened slightly, possibly indicating, in the case of the PVC FMLs,
loss of plasticizer and, in the case of the CSPE and CPE FMLs, crosslinking of
the polymers. They all recovered most of the tensile properties that were
lost due to the initial softening. These 3 FMLs were thermoplastic, unvul-
canized, and noncrystalline.
Of the 6 FMLs, the LDPE, which is semi crystal line, best retained the
original values of the properties during the exposure period, as is shown in
Table 9; it also absorbed the least amount of leachate. However, this FML,
which was 10 mils in thickness, has too low a puncture resistance for use in
lining an MSW landfill. Subsequent to these studies, thicker FMLs based on
HDPE, medium density polyethylene (MDPE), and linear low-density polyethylene
(LLDPE), which have greater chemical resistance, durability, and adaptability
to various applications than does LDPE, have been Introduced and are being
used as lining materials. However, the basic properties of these polyethyl-
enes are quite similar in many respects.
The butyl rubber and EPDM FMLs changed slightly more in physical prop-
erties than did the LDPE FML during the exposure period.
It is postulated that the minor effects upon the FMLs of the MSW leach-
ate generated for the study conducted by Haxo et al (1982) can probably be
attributed to the absence of chlorinated organics, aromatic hydrocarbons, and
other volatile organics that are now known to affect hydrocarbon FMLs. The
leachate composition that was determined during the course of the study con-
tained high levels of organic acids, a high chemical oxygen demand, and was
considered to be a typically strong MSW leachate. However, no analyses were
made for the volatile hydrocarbons and chlorinated solvents.
Basic physical chemistry demonstrates that the presence of electrolytes
in an aqueous solution containing dissolved organics, such as are in MSW
leachates, is known to affect the solubility of organics in water, i.e.
reduces solubility. It can be anticipated that the presence of electrolytes
in an MSW leachate can affect the partitioning of dissolved organics and the
absorption of the organics by a polymeric material, i.e. an FML. Such an
effect appears to be exhibited by the difference in the weight gains by FMLs
immersed in water and in MSW leachate, as is shown in Table 10. With the
significant exception of PVC FMLs, those that absorbed more 1n water were the
chlorine-containing polymers, and those that absorbed less were hydrocarbon
polymers, e.g. butyl rubber and EPDM. In the latter case, the organics in
the leachate were absorbed by the FMLs. It has been previosuly observed and
commonly reported that the absorption of water by a neoprene compound, a
31
-------
chlorine-containing rubber, decreases with increasing salt concentration and
that DI water in particular swells neoprene compositions (Murray and Thompson,
1963). This is confirmed by the results shown for neoprene in Table 10, as
the leachate contained significant amounts of dissolved salts. The compo-
sition of the leachate at the end of the first year of operation of the
simulators is presented in Table 11.
TABLE 10. WATER AND LEACHATE ABSORPTION BY FMLS
(Data in percent absorbed by weight)
Water
at room
FML
temperature,
Leachate,
Type of FML
number3
1 year
1 year
Butyl rubber (cross!inked)
7b
1.60
1.78
Chlorinated polyethylene (CPE)
12b
13.10
9.0
13c
19.60
12.4
Chlorosulfonated polyethylene
3
17.40
20.0
6b,c
9.20
13.64
14c
11.20
8.71
Ethylene propylene rubber (EPDM)
16b
4.80
5.50
(crosslinked)
25
1.50
5.99
Neoprene (crosslinked)
9
22.7
8.73
Polybutylene
20
0.25
0.33
Polyethylene
21b
0.20
0.25
Polyvinyl chloride
10
1.85
6.72
11
1.85
5.0
15
2.10
4.64
17b
1.85
3.29
19
0.60
0.75
aMatrecon FML identification number.
^Liners mounted in generator bases.
cFabric-reinforced FML.
Source: Haxo et al (1982).
Immersion of FMLs in Flowing MSW Leachate
In Table 12 the absorption of the primary and the buried FML strip
specimens after 12 months of exposure to leachate is compared with that of
32
-------
TABLE 11. ANALYSIS OF LEACHATE0
Test Value
Total solids, % 3.31
Volatile solids, % 1.95
Nonvolatile solids, % 1.36
Chemical oxygen demand (COD), g/L 45.9
pH 5.05
Total volatile acids (TVA), g/L 24.33
Organic acids, g/L
Acetic 11.25
Propionic 2.87
Isobutyric 0.81
Butyric 6.93
aAt the end of the first year of operation
when the first set of liner specimens was
recovered.
Source: Haxo et al (1982) and Materecon (1988).
TABLE 12. SWELLING3 OF FMLS ON EXPOSURE TO HSW LEACHATE
Exposed in ;
simulators,
months
Immersion in
flowing
Primary
Buried
in sand
leachate, months
Type of FKL
12
56
12
56
8
19
30.5
Butyl rubber
2.0
2.4
1.8
2.0
1.4
2.6
1.96
Chlorinated polyethy-
lene
6.8
7.61
9.0
10.1
7.9
14.4
9.95
Chlorosulfonated poly-
ethyl ene
12.8
a
13.90
20.0
13.6
14.7
17.0
18.6
12.1
22.8
14.9
17.24
14.53
Ethylene propylene
rubber
5.54
5.74
6.0
6.5
2.9
3.8
5.98
Polybutylene
0.3
0.2
-0.2
0.7
0.46
Polyethylene (low-
density)
0.02
1.95
0.3
0
0.2
0.10
Polyvinyl chloride
3.6
2.08
5.0
3.3
0.8
2.0
1.30b
0.5
2.4
2.3
0.9
4.4
4.4
1.9
3.87
3.02
1.45
aMeasured by percent volatiles of the exposed material.
bForty-three months in simulator.
Source: Haxo et al (1982).
33
-------
specimens of similar materials immersed in leachate for 8 and 19 months. The
data show that the buried specimens, both sides of which were exposed to the
leachate, tended to swell slightly more than the primary specimens that were
exposed to the leachate on only one side. The swelling of the specimens, that
were immersed completely in leachate which flowed by the specimens as they
hung in the immersion cells, was equal to or greater than the swell of the
buried specimens. Leachate flowed by the latter specimens but at a slower
rate.
Overall, these results indicate that, except for the chlorine-containing
FMLs, the MSW leachate tended to swell the FMLs more than did water, and that
two-sided exposure yields somewhat higher swelling values. In some cases,
there was a leveling off with time of the degree of swelling by the leachate.
However, the composition of the leachate was simultaneously changing, with the
levels of the organic constituents dropping with time.
Significant differences in properties and the effects of exposure can be
observed among the FMLs of a given generic type, as is shown in Table 13.
These differences are shown by the effects on the S-200 stress of the FMLs of
8, 19, and 31 months of immersion in leachate and by the effects on tensile
strength, as are shown in Figures 3 and 4.
FMLS IN DILUTE AQUEOUS SOLUTIONS OF ORGANICS POTENTIALLY PRESENT IN
MSW LEACHATES
Absorption of Dissolved Organics from Dilute Solutions by
Polyethylene FMLs
To simulate concentration of organics in leachates, a series of experi-
ments was conducted by Haxo et al (1988) to assess the absorption of organics
from dilute aqueous solutions of various organics, either singly or in mix-
tures. These experiments included:
- An exploratory experiment to assess the absorption of organics by a
PE FML which had been placed in a dilute aqueous mixture of five
volatile organics at less than the solubility limits of each.
- Absorption of individual organics by PE FMLs immersed in sepa-
rate cells, each containing one of nine volatile organics.
- Distribution to DI water of an organic from an FML specimen saturated
with a single volatile organic.
- Two compatibility experiments (EPA Method 9090, modified) 1n which
mixtures of organics placed in an exposure cell were absorbed by
a PE FML. One experiment was performed with an actual hazardous
waste leachate which had been spiked with a mixture of seven volatile
organics and the second experiment was performed with a aqueous sol-
ution of 11 organics, Including nine volatile organics.
34
-------
, TABLE 13. RETENTION OF MODULUSa OF FMLS ON IMMERSION IN MSW LEACHATE
Stress at 200%
elongation of Retention on exposure
unexposed FML, of original value, %
Type of FML
psi
8 mo.
19 mo.
31 mo.
Butyl rubber (crosslinked)
685
86
90
98
Chlorinated polyethylene
1330
85
89
95
1205
89
90
104
810
98
106
133
Chlorosulfonated polyethylene
735
54
46
57
1525b
116b
136b
1770
77
108
130
Ethylene propylene rubber
655
134
131
134
(crosslinked)
755
111
109
117
920b
98b
98b
104b
855
91
92
98
Neoprene (crosslinked)
1235
79
77
76
1340
93
101
115
Polybutylene
3120
101
101
106
Polyethylene (low-density)
1260
106
102
106
Polyvinyl chloride
2125
87
85
98
1965
80
84
94
1740
89
94
112
1720
91
91
104
1705
92
105
117
2400
79
88
101
2455
96
95
105
aAverage of stress at 200% elongation (S-200) measured in machine and
transverse directions.
bFML is fabric reinforced.
Source: Haxo et al (1982).
Absorption by PE FML of a Mixture of Volatile Organics
The absorption of the volatile organics by a PVC FML immersed in a
waste liquid was measured by headspace gas chromatography of the FML.
35
-------
CO
CTi
z
o
5 100
uj
OC
0
200
2
O
P
2 too
ป-
ui
cc
z
o
100
GC
a?
8UTYL RUBBER
CPE
CPE
CPE
NO. 44
NO. 12
NO. 38
NO. 86
-
-
-
-
- T0 - 1600 PSI
_ T0 - 2275 PSI
~ 1 I III
_ Tq - 2095 PSI
1 1 1 1 1
Tq - 1680 PSI
1 1 1 1 1
CSPE
CSPE
CSPE
ELASTICI2ED POLYOLEFIN
NO. 3
~ NO. 6 (FABRIC REINFORCED)
NO. 85
NO. 36
- T0 - 1640 PSI
1 1 1 1 1
- Tq - 1765 PSI
1 1 1 f 1
- Tq - 2200 PSI
(III)
- Tq - 2620 PSI
f 1 1 1 1
EPDM
EPDM
EPDM
EPDM
NO. 8
NO. 18
NO.41
-NO.B3 (FABRIC REINFORCED)
_ T0 - 1875 PSt
- T0 1480 PSI
- To - 3005 PSI
- Tq - 940 PSI
-
-
-
-
1 1 1 1 _ _l
1 t 1 1 1
1 1 1 1 1
1 1 1 1 1
200 400 600 800 1000
DAYS EXPOSED
0 200 400 600 800 1000
DAYS EXPOSED
0 200 400 600 BOO 1000
DAYS EXPOSED
200 400 600 800 1000
DAYS EXPOSED
Figure 3. Retention of FML tensile strength as a function of immersion time In MSW
leachateButyl rubber, CPE, CSPE, ELPO, and EPDM FMLs. Tensile strength
values based upon the average data obtained in the machine and transverse
directions. Matrecon identification numbers and initial tensile strength
for each FML are shown. Data are given for 8, 19, and 31 months. (Source:
Haxo et al, 1982, p 85).
-------
OJ
z
o
2
UJ
h
ui
cc
0
200
2
O
0
200
z
o
z
uj 100
z
o
5 100
QC
X
EPDM
NO. 91
NEOPRENE
NO. 9
NEOPRENE
NO. 37
NEOPRENE
- NO. 42 (FABRIC REINFORCED)
" TQ - 1830 PSI
1 1 1 1 1
_ Tq - 2195 PSI
1 1 1 1 1
- To - 2365 PSI
1 1 1 1 1
_ T0 - 262 PPI
1 1 1 1 1
NEOPRENE
NO. 90
POLY0UTYLENE
NO. 98
POLYESTER ELASTOMER
NO. 75
LDPE
NO.21
_ T0 - 2100 PSI
1 1 1 1 1
- T0 - 6605 PSI
1 1 1 1 1
_ T0 - 6770 PPI
1 1 1 1 1
- T0 - 2145 PSI
1 1 1 1 I
PVC
NO 11
PVC
NO. 17
PVC
NO. 19
PVC
NO. 40
~ T0 2960 PSI
1 1 t 1 1
~ T0 - 2580 PSI
1 1 1 1 1
~ T0 2520 PSI
1 1 111
ฆ ป > 0
- Tq - 2790 PSI
PVC
NO. 67
PVC
NO. 88
PVC
NO. 89
PVC AND PITCH
NO. 52
~ To - 2895 PSI
1 1 1 1 |
" T0 - 3155 PSI
" T0 - 3400 PSI
1 1 1 1 1
" TQ - 1095 PSI
"ill II
0 200 400 600 BOO 1000
DAYS EXPOSED
200 400 600 800 1000
DAYS EXPOSED
0 200 400 600 800 1000
HAYS EXPOSED
0 200 400 600 800 1000
DAYS EXPOSED
Figure 4. Retention of FML tensile strength as a function of immersion time in MSW leachate--
EPDM, neoprene, PB, PEL, LDPE, PVC, and PVC-pitch FMLs. Tensile strength values
based upon the average data obtained in the machine and transverse directions.
Matrecon identification numbers and initial tensile strength for each FML are
shown. Data are given for 8, 19, and 31 months. (Source: Haxo et al, 1982, p 85).
-------
In a typical experiment, an HDPE sample that had been exposed to a test
solution containing trichloroethane (TCA), trichloroethylene (TCE), benzene,
toluene, and xylenes in the concentrations shown in Table 14 was analyzed for
volatile organics by headspace GC. The results of this analysis are also
presented in Table 14. The results (Haxo et al, 1988) showed that the
organics tested partition to the FML phase to yield concentrations many fold
greater than the concentrations in the aqueous solutions. For example, the
concentration of the xylenes in the PE was 62 times the concentration in the
aqueous phase. It should be noted that the acetone and MEK that were present
in the original waste liquid were not detected in the headspace GC analysis of
the PE sample.
Distribution of Organics Between Organic Saturated Water and a PE FML--
To assess the distribution of dissolved organics between an aqueous
solution and FMLs, a series of saturated aqueous solutions, each containing
a single organic, were prepared with an excess of the organic and placed in
vapor-tight jars. Since acetone, which was in this series, is miscible with
water in all proportions, the aqueous solution was prepared at 250,000 mg of
acetone per L of solution.
TABLE 14. PARTITIONING OF DISSOLVED VOLATILE ORGANICS FROM
AQUEOUS SOLUTIONS TO IMMERSED POLYETHYLENE FML
Organics Concentration
Initial in exposed FMLa in pHL
Organic
concentration
in leachate,
mg/L
Head-
space,
mg
Concentration
in FHLb,
mg/L
divided by
concentration
in leachate
1,1,1-Trichloroethane
250
22.6
9,650
40x
Trichloroethylene
250
27.7
11,820
47x
Benzene
125
4.0
1,710
14x
Toluene
125
12.9
5,510
45x
Xylenes (mixture of
o-, m-, and p-)
125
17.6
7,510
62x
Total
875
84.8
36,200
41x
aExposed PE specimen in test was 2.3433 g before 110ฐC headspace heating
and 2.2735 g after 19.5 h heating, for a volatiles loss of 0.0698 g or
2.98% of the initial weight.
^Determined by headspace GC.
Source: Haxo et al (1988).
38
-------
A specimen of a PE FML was Immersed in- each jar. At intervals, each
specimen was removed and weighed until each had reached a maximum value;
the concentration of the organic in the FML specimen was calculated and re-
ported in mg of organic per L of polymer volume, i.e. per L of FML. The
values used for the concentrations of the organics in the saturated aqueous
solutions, which were assumed to be concentrations at saturation, were
obtained from the literature (Riddick and Bunger, 1970). The distribution
coefficients, i.e. the ratio of the concentration of the organic in the FML
(CFML) t0 the concentration in the aqueous solution (C^oK were calculated.
The results of the analyses and calculations are presented in Table 15.
In all cases, more than 30 days were required for the specimens to reach
maximum swelling. The time required to reach maximum swelling ranged from
30 days for the specimen immersed in benzene solution to 52 days for the
specimen immersed in the TCA solution. The distribution of all of the or-
ganics, except the acetone and MEK, were predominantly to the PE specimens and
ranged in distribution coefficients from 54 for benzene to 422 for o-xylene.
Distribution of Organics Between a Saturated PE FML and Deionized Water--
An experiment complementary to that described above was performed. In
this experiment, specimens of the same PE FML were individually saturated
with each of the same organics and then immersed in DI water in separate
vapor-tight jars. The concentrations of the organics in the respective jars
were monitored with time by sampling and GC analysis until they had reached
maximum values which indicated equilibrium had been established. At that
time, the specimen was removed and the concentration of the organic remain-
ing in the specimen was determined by headspace GC.
Data that were obtained on the weight of the specimen at saturation,
as well as the weight of the swollen specimen after equilibrating with the
water in the jars and the time required to reach equilibrium, are presented
in Table 16. The rate at which the absorbed organics diffused out of the
FML into the water varied considerably. It took 24 hours for the FML speci-
men containing TCE to reach an equilibrium concentration, whereas the speci-
men containing the benzene required 120 hours. The concentrations of the
xylenes in the water approached their solubilities in water and probably
left an excess in the HDPE specimens. Consequently, the distribution coef-
ficient may be somewhat higher. It did not appear that equilibrium had been
reached with acetone and MEK when the specimens were withdrawn.
The distribution coefficients, also presented in Table 16, show the
strong tendency of the chlorinated and aromatic organics to remain in the
PE FML. The data also show that organics absorbed by an FML are in equi-
librium with those in aqueous solution and that the organic can migrate out
of an FML if the activity of the organic is lower in the water than in the
FML.
Absorption of Mixtures of Organics from Spiked Leachates and from a Dilute
Aqueous Solution
Compatibility test of a PE FML performed with an actual leachate spiked
with selected organics--A short-term exploratory compatibility test was
39
-------
TABLE 15. DISTRIBUTION OF NINE VOLATILE ORGANICS BETWEEN SATURATED AQUEOUS
SOLUTIONS AND SPECIMENS OF A POLYETHYLENE FMLa
Solubility
Concen-
in water
Weight
tration
at room
Time to
increase
of organic
Density
temperature^
maximum
of HDPE FML
in swollen
Distribution
of organic,
(Ch2o).
swelling,
specimen,
FML (Cfml),
coefficient,
Organic
g/mL
mg/L
days
%
mg/L
cfml/%o
Acetone
0.788
250,000ฐ
44
0.33
3,210
0.0128
Methyl ethyl ketone
0.805
240,000
46
0.62
5,900
0.0246
Trichloroethylene
1.464
1,100
43
16.71
144,200
131.0
1,1,1-Trichloroethane
1.339
1,320
52
11.70
103,000
78.2
Benzene
0.879
1,180
30
7.22
63,900
54.3
Toluene
0.866
515
50
8.05
70,600
137
o-Xylene
0.897
175
40
8.42
73,800
422
m-Xylene
0.868
196
38
8.19
71,800
366
p-Xylene
0.854
190
49
8.43
73,600
387
aHDPE FML.
^Values obtained from Riddick and Bunger (1970).
cInitial concentration of the acetone-water solution; acetone is miscible with water in all
proportions.
Source: Haxo et al (1988).
-------
TABLE 16.
DISTRIBUTION
OF ORGANICS
BETWEEN
AN ORGANIC
SATURATED FMLa
AND DEIONIZED
WATER
At equilibrium in deionized water
Saturated FML
Time to
maximum
Concen-
tration
Organic
Maximum
swelling
(by weight),
%
Concen-
tration
of organic,
mg/L
concen-
tration
in H2O,
hours
Swel1i ng
of FML (by
weight),
%
Concentration
of organic
in FML (Cfml)
mg/L
of organic
in water
(%o)ป
mg/L
Distribution
coefficient
Cfml/ch2o
Acetone
0.96
9,080
~120b
0.62
5,830
35
167
Methyl ethyl
ketone
1.83
17,120
~120b
0.91
8,990
127
71
Trichloro-
ethylene
17.52
150,500
24
8.98
84,800
966
88
1,1,1-Trichlo-
roethane
12.13
106,700
50
6.91
65,800
589
112
Benzene
7.61
67,100
120
1.95
19,030
643
30
Toluene
8.40
73,400
46
4.42
42,000
266
158
o-Xylene
8.73
76,300
52
7.07
65,600
186
352
m-Xylene
8.51
74,300
78
6.70
62,200
193
322
p-Xylene
8.72
75,900
58
6.93
64,300
165
390
aHDPE FML.
bEquilibrium did not appear to have been reached when specimen was removed from test at 120 hours.
Source: Haxo et al (1988).
-------
performed by Haxo et al (1988) on an HDPE FML with a leachate that had been
obtained from a hazardous waste landfill and was spiked with a group of
volatile organics. Spiking a leachate with constituents that are or may be
in a leachate was considered to be a means of accelerating a compatibility
test since it would increase the severity of the exposure conditions. It is
also desirable to introduce known species of organics which can be absorbed
by the FML from dilute aqueous solutions and tracked relatively easily by GC.
The availability of a waste liquid that contained volatiles furnished the
researchers the opportunity of running a short-term test to assess the effects
of the volatiles and to observe possible loss of volatiles during testing.
The results would be useful in determining the need for replenishment of the
waste liquid during exposure in an EPA Method 9090 test.
In this experiment a 60-mil PE FML was exposed to an actual leachate
which had been spiked with a mixture of volatile organics known to be aggres-
sive to FMLs, and which may be found in MSW leachates. The leachate was
first placed in the exposure tank and then was spiked with the mixture of
volatile organic solvents. Quantities of benzene, toluene, and the xylenes
greater than their calculated solubilities were added to the leachate in order
to assure saturation over a period of time. The components of the spiking
mixture and their calculated concentrations, if completely soluble in the
leachate, are presented in Table 17.
TABLE 17. COMPOSITION OF THE SPIKING MIXTURE
Component
Specific
gravity
Weight,
9
Volume,
mL
Concen-
tration in
tank3, if
completely
soluble,
mg/L
Solu-
bi1i ty
in water,
mg/L
Trichloroethylene
1.464
10
6.83
503
1,100
1,1,1-Trichloroethane
1.339
10
7.47
503
1,320
Benzene
0.879
29
33.00
1,473
1,178
Toluene
0.867
19
21.92
965
515
o-Xylene
0.880
58
65.89
2,947
175
m-Xylene
0.861
8
9.29
406
196
p-Xylene
0.864
41
47.44
2,083
190
Mixture of the above
seven components
0.912
175
191.84
8,880
b
a5.20 gal = 19,682 mL.
t>Not determined.
Source: Haxo et al (1988).
42
-------
The spiked leachate and the exposed FML were analyzed by GC for five
organics; the spiked leachate was analyzed after all of the organics had
been added, and the FML was analyzed after 18 days of immersion. The results
are presented in Table 18. The exposed FML was analyzed by headspace GC,
which was performed by heating the specimen in a headspace container at 105ฐC
for 48 hours. The volatile organics totaled 44,380 mg/L, which agrees rea-
sonably well with the percent volatiles that was measured after 20 days of
immersion.
TABLE 18. GC ANALYSIS OF LEACHATE AND FML SAMPLES
Concentrations of Organics
Spiked
HDPE
leachate,
FMLa,
Organic
mg/L
mg/L
Trichloroethylene
53
780
1,1,1-Trichloroethane
76.9
250
Benzene
232
1,590
Toluene
63
2,960
o-, m-, and p-Xylenes
134
38,800
Total
44,380
determined by headspace GC analysis on heating the FML
specimen for 48 h at 105ฐC.
Source: Haxo et al (1988).
The data presented in Table 18 showed the high concentration of the
aromatic organics in the FML compared with that in the leachate. These
results indicated the strong affinity of the aromatic organics for the HDPE
FML, and reflect the closeness of their solubility parameters.
The results of this experiment clearly showed the importance of prevent-
ing the loss of volatiles organics in the exposure tanks, but, even with ex-
cessive organics, volatiles were lost from the tanks. Increases in the weight
of the slabs and in their volatiles content after three weeks of exposure to
the spiked leachate indicated significant absorption of the volatile compo-
nents of the spiked leachate. These increases were accompanied by significant
changes in some physical properties. For example, there were significant
losses in tensile at yield, tensile strength, modulus, puncture resistance,
and hardness. When a slab was returned to the tank and allowed to continue in
exposure after the 27th day, the volatiles content dropped substantially and
the properties returned closely to baseline values. This return to baseline
values indicates that most of the property changes that occurred in the early
part of the exposure were due to swelling. The Teflon gasket, which normally
is replaced at the end of each test interval, was not replaced as it appeared
to be in good condition at the end of 20 days of exposure.
43
-------
It was concluded that at each time interval When the tanks are opened to
recover the samples for testing, the leachate should be replaced with fresh
leachate to return the medium to its original concentration. Furthermore,
the sealing gasket should be changed, and the sealing surfaces of the cover
and the metal container should be checked carefully.
Absorption of organics by a PE FML from an aqueous solution containing
11 orqanics--In a similar type of experiment by Haxo et al (1988), specimens
of a PE FML were immersed in an aqueous solution of DI water and 11 different
organics, both volatile and nonvolatile. The concentrations of the organics
are shown in Table 19, and all except for the di(ethylhexyl} phthalate (DEHP)
were well below their respective solubilities in water.
TABLE 19. CONCENTRATION OF ORGANICS IN AQUEOUS SOLUTION
Concentration
Organics in tank, mg/L
Acetone
197
Methyl ethyl ketone (MEK)
201
1,1,1-Trlchloroethane (TCA)
290
Trichloroethylene (TCE)
363
Benzene
220
Toluene
217
o-Xylene
73
m-Xylene
72
p-Xylene
72
Tri-n-butyl phosphate (TBP)
243
Di (ethylhexyl) phthalate (DEHP)
246
Total
2,194
Source: Haxo et al (1988).
The organics that were selected included seven of the volatile organics
used in the experiment described in the previous subsection. Two additional
volatile organics, i.e. acetone and MEK, were Included in the spiking solu-
tion, as were two nonvolatile organics which are used as plasticizers for PVC
and other polymers, i.e. tri-n-butyl phosphate (TBP) and DEHP. Because TBP
and DEHP have higher molecular weights than the volatile organics, it was
anticipated that they would be absorbed more slowly by the PE than the other
organics.
The experiment was conducted as an EPA Method 9090-type compatibility
test in which the FML slabs were exposed at 23 and 50ฐC for four months in
cells containing the test solution which was not changed during the exposure.
The exposure cell is described by Haxo et al (1988), which also contains full
data on the experiment. At the end of each month, the cells were opened and
44
-------
an FML slab from each cell was removed, analyzed, and tested. At the time
of removal, the organics absorbed by the FMLs were determined by headspace GC.
The concentration of the organics in the test solution was also measured at
the end of each month by GC analysis of the solution.
The results of the headspace GC analysis of the exposed FML specimens are
reported in Table 20. The data show:
- No absorption by the FML of acetone and MEK.
- An initial absorption of the remaining volatile organics, benzene,
TCA, TCE, toluene, and the xylenes was followed by a decrease 1n all
the volatile organics.
- A gradual increase in the amounts of the two nonvolatile organics, TBP
and DEHP, absorbed by the FML.
- A lower absorption of the volatile organics at 50ฐC compared with that
at 23ฐC, and a greater absorption of the nonvolatile organics at the
higher temperature.
- The results were indicative of the loss of volatiles during the
immersion.
The effects for the PE FML in Tank 1 at 23ฐC are also illustrated in Figure
5, in which the concentrations of the absorbed individual organics in the
immersed FML are plotted as a function of time.
GC analysis of the immersion solutions yielded similar results showing
that, except for the acetone and MEK, the concentration of the volatile
organics in the solutions dropped. The concentration of these two organics
remained relatively high in the cells at 23ฐC, though they dropped in the
cells at 50ฐC. The concentration of the volatile organics in the FMLs and in
the solutions followed similar patterns after the first month of exposure. In
the case of the two nonvolatile organics, the TBP and DEHP, the concentrations
in the solutions were low at all times, indicating their low solubilities in
water.
At four months the exposure appeared to have little effect on the physi-
cal properties of the FML specimens, as is shown in Tables 21 and 22; con-
sequently, the HDPE FML appears to be compatible with the synthetic leachate,
at least to the low concentrations of organics and plasticizers present in
the water. It is likely that the loss of volatiles during the test was the
principal factor in the small effect that was observed on the FMLs. Replacing
the test solution with another portion at the same initial concentration of
organics should maintain the concentration of the organics.
The loss of volatiles at the higher exposure temperature resulted in
higher retention of properties than at the lower exposure temperature,
probably a result of the evaporation of volatile organics. These results
indicate problems in performing compatibility test at 50ฐC and higher.
45
-------
TABLE 20. HEADSPACE GC ANALYSIS OF THE EXPOSED FHL SAMPLES
P vnncnro
Volatiles in FHL by headspace GC,
mg/g
GC of
UAfJUdUl c
temperature,
m- and p-
extractables,
mg/g
tank number,
Acetone
MEK
1,1,1-TCA
Benzene
TCE
Toluene
Xylenes
o-Xylene
TBP
DEHP
and time
(197a)
(2013)
(3263)
(23ia)
(4069)
(3383)
(1913)
(1033)
Total
(2513)
(250a)
Total
Tank I (23ฐC)
34 days
0
0
1.42
0.46
1.58
2.63
1.86
1.17
8.72
0.32
0.11
0.43
69 days
0
0
0.45
0.18
0.98
1.75
4.17
1.53
9.06
5.62
0.41
6.03
105 days
0
0
0.25
0.04
0.21
0.34
1.85
0.82
3.51
6.44
0.63
7.07
139 days
0
0
0
0
0
0.02
0.19
U.04
0.25
ป i
Tank III (23ฐC)
34 days
0
0
0.68
0.30
1.26
2.25
1.33
0.80
6.62
0.08
0.08
0.16
69 days
0
0
0.18
0.05
0.30
0.81
3.00
1.03
5.37
0.52
0.14
0.66
105 days
0
0
0.08
0.01
0.07
0.16
1.26
0.53
2.11
5.29
0.32
5.61
139 days
0
0
0.02
0.00
0.01
0.05
0.08
0.00
0.16
Tank II (50ฐC)
34 days
0
0
0.1
0.02
0.16
0.66
0.78
0.57
2.29
1.61
0.31
1.92
69 days
0
0
0.01
0
0.08
0.05
1.06
0.46
1.66
3.34
0.42
3.76
105 days
0
0
0
0
0
0
0.17
0.14
0.31
9.47
0.64
10.11
139 days
0
0
0
0
0
0
0
0
0
...
i ป
Tank IV (50ฐC)
34 days
0
0
0.10
0.11
0.40
0.96
1.29
0.83
3.69
1.53
0.26
1.79
69 days
0
0
0
0.01
1.01
0.03
0.82
0.37
2.40
5.31
0.42
5.73
105 days
0
0
0
0
0
0
0.10
0.11
0.21
7.57
0.52
8.09
139 days
0
0
0
0
0
0
0
0
0
aTotal concentration 1n (mg/L) of the organics Injected In the water in two portions. Value assumes complete dissolution
in the water.
Source: Haxo et al (1988).
-------
6.B
Tributyl Phosphate
6.4
6.0
5.6
5.2 -
4.6
4.4
m/p-Xylene
"5 4.0
E
<0
C
3.6
i.
.a 3.2
a
e>
o 2.8
Toluene
J> 2.4
I
2.0
Trichloroethylene
.Trichloroethane
V-o-Xylene
1.2
0.8
Benzene
0.4
B0 100 120 140 160 180
20 40 60
0
Days of Exposure
Figure 5. Concentration as a function of time of absorbed organics in
exposed HDPE FMLs recovered from Tank I (23ฐC). The last
addition of the organics was at the beginning of the second
exposure period. (Source: Haxo et al, 1988).
47
-------
TABLE 21. COMPATIBILITY TESTING OF HDPE FHL IN DEIONIZED WATER'
SPIKED WITH 11 ORGANICS
60-Mi1 HDPE FML*3Unexposed and After One, Two, Three,
and Four Months of Exposure at 23"C in Tank I
Direction
Initial
Exposure time, months
Property
of test
values
1
2
3
4
Analytical properties
Test values
Volatiles, %
0.09
1.31
1.19
0.99
0.70
Extractables, %
0.65
0.74
0.80
0.83
1.13
Dimensional properties
Percent change
Weight
+1.2
+1.3
+1.9
+1.6
Thickness
-0.2
+0.2
+0.8
+1.2
Area
+1.2
+0.8
+0.6
+0.5
Physical properties
Percent
retention
Tensile at yield
Machine
2570 psi
104
100
109
103
Transverse
2700 psi
101
97
107
102
Elongation at yield
Machine
19%
84
79
79
89
Transverse
19%
79
79
74
79
Tensile at break
Machine
4080 psi
96
99
99
112
Transverse
4040 psi
105
117
103
101
Elongation at break
Machine
810%
97
100
100
106
Transverse
780%
104
113
101
104
Stress at 100%
Machine
1790 psi
102
99
105
102
elongation
Transverse
1840 psi
98
95
103
96
Modulus of elasticityc
Machine
111,000 psi
98
102
113
103
Transverse
118,500 psi
94
94
96
105
Tear strength
Machine
795 ppi
101
99
101
99
Transverse
785 ppi
100
99
100
100
Puncture resistance''
Test
values
Thickness, mil
60.8
63.0
62.5
60.3
62.5
Maximum stress, lb
91.7
89.5
91.8
86.0
95.4
Elongation at puncture
, in.
0.59
0.54
0.64
0.54
0.62
Stress normalized for
100-mil
Percent
retention
sheet
151 lb
94
97
95
101
Hydrostatic burst resistance
Test
values
Thickness, mil
64.7
61.3
62.0
61.0
59.9
Maximum stress, lb
557
533
518
507
535
Stress normalized for
100-mi 1
Percent
retention
sheet
861 psi
101
97
97
104
Hardness, Duro D points
Change in points
5-second reading
60
-2
-2
-2
-1
aThe immersion liquid was deionized water spiked with the following: 1,1,1-tri-
chloroethane, trlchloroethylene, benzene, toluene, ortho-, meta- and para-xylenes,
acetone, methyl ethyl ketone, di(ethylhexyl) phthalate, and tri-butyl phosphate.
bMatrecon identification number 392.
cMeasured using 0.5 x 8-in. strip specimens with an initial jaw separation of
4.0 in. and an initial strain rate of 0.1 in./in. nin. Using a specimen with a
10-in. gage length as specified in ASTM D882-83 would result in higher values.
Source: Haxo et al (1988).
48
-------
TABLE 22. COMPATIBILITY TESTING OF HDPE FHL IN DEI ONI ZED WATER*
SPIKED WITH 11 ORGANICS
60-Mil HDPE FMLbUnexposed and After One, Two, Three,
and Four Months of Exposure at 50ฐC in Tank IV
Direction Initial Exposure time, months
Property
U 1 1 CI, L 1 LMI
of test
111 1 b 1 D 1
values
1
2
3
4
Analytical properties
Test '
values
Volatiles, %
0.09
0.80
0.37
0.22
0.22
Extractables, %
0.65
0.55
0.87
0.84
1.57
Dimensional properties
Percent change
Weight
+1.1
+0.7
+0.9
+0.9
Thickness
+1.1
+0.5
+1.1
+1.4
Area
+0.6
+0.4
+0.2
+0.2
Physical properties
Percent
retention
Tensile at yield
Machine
2570 psi
109
105
107
109
Transverse
2700 psi
104
102
ioi
110
Elongation at yield
Machine
19%
79
84
100
79
Transverse
19%
84
79
95
74
Tensile at break
Machine
4080 psi
91
110
103
111
Transverse
4040 psi
105
103
9e
107
Elongation at break
Machine
810%
94
107
104
106
Transverse
780%
105
104
100
106
Stress at 100%
Machine
1790 psi
106
103
103
106
elongation
Transverse
1840 psi
100
97
98
102
Modulus of elasticityc
Machine
111,000 psi
92
96
116
120
Transverse
11B,5G0 psi
95
100
101
106
Tear strength
Machine
795 ppi
101
104
100
105
Transverse
785 ppi
101
104
100
103
Puncture resistance^
Test
values
Thickness, mil
60.8
63.8
65.0
65.0
64.3
Maximum stress, lb
91.7
95.6
100.9
97.7
98.8
Elongation at puncture, in.
0.59
0.53
0.63
0.56
0.61
Stress normalized for
100-rcil
Percent
retention
sheet
151 lb
99
103
99
102
Hydrostatic burst resistance
Test
values
Thickness, mil
64.7
62.9
66.0
63.0
63.9
Maximum stress, Tb
557
565
569
550
580
Stress normalized for
100-mi1
Percent
retention
sheet
861 psi
104
100
101
105
Hardness, Duro D points
Chanqe in points
5-second reading
60
-3
-1
-2
-2
aThe immersion liquid was deionized water spiked with the following: 1,1,1tri-
chloroethane, trichloroethylene, benzene, toluene, ortho-, meta- and para-xylenes,
acetone, methyl ethyl ketone, di(ethylhexyl) phthalate, and tri-butyl phosphate.
^Matrecon identification number 392.
cMeasured using 0.5 x 8-in. strip specimens with an initial jaw separation of
4.0 in. and an initial strain rate of 0.1 in./in. min. Using a specimen with a
10-in. gage length as specified in ASTM D882-83 would result in higher values.
Source: Haxo et al (1988).
49
-------
It was concluded from the results of the experiment that tight control
of volatiles in a liner compatibility test is essential, and that the con-
centration of all constituents in a leachate used in a compatibility test
must be maintained at original levels.
The data indicate that the use of "synthetic leachates" in liner/waste
compatibility testing requires more study. Spiking water with a few volatile
organics to produce a "leachate" does not appear to be adequate for use in
such compatibility testing and that a broader background of organics is
needed in the "leachate." It should be noted that, in the test using spiked
leachate, the volatile organics in the spike plus the organics in the original
leachate had greater effects on the properties of an FML than did the same
volatile organics at equal concentration when added in the spike to DI water.
Chemical Compatibility of FMLs
A laboratory study of FMLs was conducted by Bell en et al (1987) to
develop chemical resistance data using immersion tests. Six unreinforced
FMLs, i.e. PVC, CPE, CSPE, HOPE, epichlorohydrin rubber (ECO), and EPDM, were
investigated. The changes in properties of these FMLs were observed on
immersion in 20 test liquids (Table 23), covering a range of acidic, basic,
polar and nonpolar organics, and inorganic chemicals, several of which were
at different concentrations. In one series of tests, the physical properties
of FML specimens were measured for up to 56 days of immersion. In a second
series, changes in weight of the FMLs were measured at four-month increments
up to two years and physical properties were measured after two years of
immersion. All of the immersions were performed at 23ฐ and 50ฐC.
TABLE 23. SOLUTIONS AND LIQUIDS SELECTED FOR FML IMMERSION TESTS3
Concentration
Liquid
Formula
Type
(percent wt:wt)
Water (distilled)b
Hydrochloric acid
Sodium hydroxide
Sodium chloride^
Potassium dichromate
Phenolb
Furfural^
Methyl ethyl ketone^
1,2-Dichloroethaneb
ASTM #2 Oil
H20
HC1
NaOH
NaCl
K2Cr207
C6H5OH
C4H3OCHO
CH3C0C2H5
C1(CH2)2C1
Control
Acid
Base
Salt
Oxidizer
Phenol
Aldehyde
Ketone
Chlorinated-
hydrocarbon
Oil
100
10
10
10b,
10
1,4,
1,4,
3,13
0.1,
saturated (ca 35)
saturated (ca 8)
saturated (ca 8)
, saturated (ca 26)c
0.5, saturated (ca 0.8)
100%, saturated (water with
oil stirred in)
aAll chemicals were technical-grade quality or better (ASTM D543).
bSolution or liquid pertinent to FML/MSW leachate compatibility.
cAn 8% solution of methyl ethyl ketone was used in place of the saturated
solution for CPE testing.
Source: Bellen et al, 1987 (Table 13).
50
-------
Fourteen of the 20 immersion liquids appear to be relevant to a discus-
sion of the compatibility of FMLs in MSW leachates; these liquids are in-
dicated in Table 23 (footnote "b"). Though the "low" concentration aqueous
solutions are probably higher in concentration than would be encountered in
the MSW leachates, the 14 liquids include a range of concentrations down to
1% for phenol and furfural, 3% for MEK, and 0.1% for dichloroethane (DCE).
In the last organic, the concentration of 0.1% (1000 ppm) approaches con-
centrations of organics observed in some leachates.
Four of the six FMLs are relevant to MSW landfill liners. The baseline
data for the physical properties of the four FMLs (PVC, CPE, CSPE, and HDPE)
that are of interest for this discussion are presented in Appendix A. The
tests that were used by Bell en et al (1987) are presented 1n Appendix B.
These tests were all physical and no analytical data were presented to give
information on the composition of the FMLs. Data with respect to plasticizer
and polymer contents are particularly useful in interpreting long-term ex-
posure data for compatibility and durability. Consequently, samples of
these four FMLs were obtained from the National Sanitation Foundation through
the EPA Technical Project Monitor and were analyzed for extractables and by
thermogravimetry (TGA) for carbon black and ash. The results of these anal-
yses are reported in Section 6 "Experimental Work" (Table 39). No analytical
data are available on the exposed specimens to assess the changes that may
have taken place during the immersions. The polymer contents of each FML were
calculated and are presented in Table 39. They show that the polymer contents
of the HDPE, PVC, CPE, and CSPE-LW were 96, 52, 74, and 46?!, respectively.
The PVC contained 34% plasticizer and the CSPE-LW contained about 46% filler,
most of which was inorganic.
Test results for the PVC immersed for 713-737 days, the CPE immersed for
712-734 days, the HDPE immersed for 738-772 days, and the CSPE-LW immersed for
240-242 days are presented in Appendixes C and D. These data were extracted
from various tables in Bellen et al (1987). They Include the final data for
percent swelling, stress at 1002 elongation, tensile strength, and elongation
at break for the samples that had been immersed at 23ฐ and 50ฐC in the 14
liquids, Including all three concentrations of phenol, furfural, MEK, DCE, DI
water, and a 10% NaCl solution.
Some of the general observations that can be made from these data are:
- In the cases of CPE and CSPE, except for DCE at 50ฐC, the percent
swelling increases substantially with increasing concentration. The
effect of increasing concentration was negligible in the case of the
HDPE and variable with respect to the PVC depending on the immersion
temperature. In the immersion at 23ฐC, the swelling increased several
fold, but for the immersion at 50ฐC the swelling by the phenol solu-
tion was less for the 8% concentration than for the 1%, and the
swelling by MEK went through a maximum at 13% concentration.
- The CPE and CSPE FMLs swelled significantly more at 50ฐC than at 23ฐC.
On the other hand, swelling of HDPE, which was only a few percent and,
for most immersions, was slightly less at 50ฐC compared with the
51
-------
swelling at 23ฐC. The swelling of the PVC FML varied with the organic
and its concentration in water indicating differences that were probably
due to the extraction of plasticizer.
- Retention of tensile strength and stress at 100% elongation (S-100) of
the specimens immersed at lower concentrations is significantly higher
than those immersed at higher concentrations and, for most immersions,
there was a tendency toward higher elongations.
- There was a great spread in the values of retention of properties
for a given level of swelling. For example, the swelling of CSPE-LW of
12.6% results in a retention of S-100 of 53%, whereas the swelling of
CSPE-LW by distilled water of 19% results in no change in S-100. The
16% swelling of PVC by phenol resulted in an increase in retention of
S-100 of 149%, indicating an extraction of plasticizer.
- Swelling on immersion in distilled water of CPE and CSPE-LW is
significantly greater than that in NaCl solutions. It should be
noted that all of the aqueous solutions contained distilled water;
consequently, the distilled water becomes a control for the effects
of the various solutions. Generally, the swelling of the FMLs in the
distilled water is less than that of a solution containing organics.
From the stand point of individual FMLs, the following observations can
be made:
- The HDPE showed the least swelling in all of the solutions and the most
uniform retention of property values of S-100, tensile strength, and
elongation at break. Also, the effects of increasing concentration
were small, only about 1% in swelling. The retention of tensile
strength and elongation are higher for samples immersed at 50ฐC than
for those immersed at 23ฐC. This difference may reflect changes in
crystallinity of the PE.
- The PVC FMLs show reversals in swelling and property retention values
on immersion at the higher temperature of 50ฐC. The samples immersed
in the MEK exhibited drastic losses in S-100 and tensile strength on
exposure at 23ฐC, but at 50ฐC there was a major increase in tensile
strength and a retention of only 6% in elongation. MEK is a solvent
for PVC and at the higher MEK concentrations, the PVC probably showed
the effects of the extraction of the plasticizer.
- Of the four FMLs, the CPE exhibited the greatest swelling and the
greatest losses in properties at both immersion temperatures (23ฐ and
50ฐC). Swelling in the organic solutions increased with increasing
concentration on all immersions, except possibly in the 26% MEK
solution at 50ฐC. Also, the swelling in distilled water is parti-
cularly large compared with the immersion in 10% NaCl solution.
- The CSPE-LW FML specimens immersed in the liquids for 240-242 days
swelled moderately with a maximum at 23ฐC of about 20% and about 44%
52
-------
at 50ฐC. The swelling in the organic solution increased with con-
centration at both 23ฐC and at 50ฐC. Concurrent with the swelling
were drops in S-100 and tensile strength and increases in elongation
at 23ฐC, but decreases at 50ฐC. The swelling in distilled water was
a significant factor in the swelling in all the aqueous organic sol-
utions. The swelling in the NaCl solution was only 0.1% and 0.8% at
23ฐ and 50ฐC, respectively. This result demonstrates the effects of
electrolytes in the water to reduce swelling compared with pure water.
DCE is of particular interest because of the low concentration at which
it was used, i.e. 0.1% to 0.8% (1000 to 8000 ppm). The effects of the im-
mersion in 0.1% solution of DCE were significant, as is shown in Table 24
composed of data extracted from Appendixes C and D.
TABLE 24. EFFECTS OF IMMERSION IN 0.1%
SOLUTION OF DCE IN WATER
Retention. %
FML
Immersion
time, days
Swellinq, %
S-
100%
23ฐC 50ฐC
23ฐC
50ฐC
PVC
730
1.0 3.0
95
101
CPE
727
22.0 123.0
85
87
HDPE
763
0.4 0.1
101
105
CSPE-LW
741
3.8 20.0
74
57
Source: Appendixes C and D.
Some of the data that are reported by Bellen et al (1987) on the effect
of swelling versus time show the slow swelling that can take place in some
of the FMLs, indicating that at the lower concentrations extended periods
of time are required, e.g. more than 782 days in some cases, to achieve
equilibriun.
USE OF SOLUBILITY PARAMETERS IN ESTIMATING COMPATIBILITY
OF FMLS AND MSW LEACHATES
The possible use of solubility parameters in predicting the compatibil
ity of FMLs with waste leachates and other liquids was investigated by Haxo
et al (1985, 1986, 1988, and Matrecon 1988), as part of a general study of
the factors affecting the compatibility of FMLs and waste liquids. These
parameters have found wide use in a variety of industries concerned with
the manufacture and use of polymeric materials. In the paint and coating
industry, solubility parameters are used in determining the solubility of
polymeric materials in different solvents. In the rubber and plastics in-
dustries, these parameters have also found considerable use in the study of
the plasticization of polymers, in the preparation of polymer blends and
53
-------
alloys, and 1n the designing of polymeric compositions for contact with oils,
hydraulic fluids, and gasolines (Barton 1975 and 1983). The last use is
closely related to the selection of FMLs and the assessment of probable per-
formance characteristics of FMLs for the lining of waste and secondary con-
tainment facilities. Polymeric compositions such as FMLs that have solu-
bility parameters similar to those of liquids tend to be swollen or dis-
solved by them, as is illustrated in Figure 6. The solubility parameter of
a polymeric composition can be determined by immersing specimens in liquids
of different solubility parameters and determining the value at which the
maximum swelling or solutioning occurs.
Linear polymer
infinitely miscible
with solvent
o>
c
Q>
s
E
3
Uncrosslinked
polymer
Uncrosslinked
polymer
3
W
UJ
i i
Crosslinked
polymer
ซo V
Solubility parameter, 5 of solvent
Figure 6. Equilibrium swelling of a crosslinked noncrystalline polymer and
of an uncrosslinked noncrystalline polymer as a function of the
solubility parameter of the solvent in which the polymer is
immersed (from Van Krevelen and Hoftzer, 1976). The crosslinked
polymer has a limiting maximum swelling at its solubility param-
eter value. The magnitude of the swelling depends on the degree
of crossllnking. An uncrosslinked noncrystalline polymer will
dissolve in a solvent having the same or close to the same solu-
bility parameter as the polymer.
The solubility parameter values of a range of different solvents, most of
which can be found 1n waste streams, are illustrated in Table 25. The lowest
54
-------
TABLE 25. SOLUBILITY PARAMETER VALUES3 FOR SELECTED SOLVENTS
Name
6.
(cal cm-
ฆ3)1/2
6
fit
fid
fip
ซh
Alkanes
n-Octane
7.6
7.6
7.6
0.0
0.0
Cyclohexane
8.2
8.2
8.2
0.0
0.1
Aromatic hydrocarbons
Benzene
9.2
9.09
8.94
0.49
1.02
Toluene
8.9
8.9
8.75
0.54
1.03
o-Xylene
8.8
8.B
8.7
0.5
1.5
Tetrahydronaphthalene
9.5
9.B
9.6
1.0
1.4
Halohydrocarbons
1,1-Di chloroethy1ene
9.1
9.2
8.3
3.3
2.2
Trichloroethylene
9.3
9.3
6.B0
1.42
2.59
Ethylene dichloride
9.B
10.2
9.3
3.6
2.0
Carbon tetrachloride
B.6
B.7
B.7
0.0
0.3
Tetrachloroethylene
9.3
9.9
9.3
3.2
1.4
1,1,2,2-Tetrachloroethane
9.7
10.6
9.2
2.5
4.6
Ethers
Epichlorohydrin
11.0
10.7
9.3
5.0
1.8
Tetrahydrofuran
9.1
9.5
B.2
2.B
3.9
Ketones
Acetone
9.9
9.8
7.6
5.1
3.4
Methyl ethyl ketone
9.3
9.3
7.8
4.4
2.5
Diethyl ketone
8.8
8.9
7.7
3.7
2.3
Aldehydes
Furfural
11.2
11.9
9.1
7.3
2.5
Esters
Ethyl acetate
9.1
8.9
7.7
2.6
3.5
D1-n-butyl phthalate
9.3
9.9
8.7
4.2
2.0
Tributyl phosphate
8.8
8.9
8.0
3.1
2.1
Tricresyl phosphate
8.4
11.3
9.3
6.0
2.2
Dioctyl phthalate
7.9
8.9
8.1
3.4
1.5
Nitrogen compounds
Pyridine
10.7
10.7
9.3
4.3
2.9
Quinoline
10.8
10. B
9.5
3.4
3.7
Formamide
19.2
17.9
8.4
12.8
9.3
Sulfur compound
Carbon disulfide
10.0
9.9
5.3
8.1
2.1
Monohydric alcohol
Ethanol
12.7
13.0
7.7
4.3
9.5
1-Propanol
11.9
12.0
7.8
3.3
8.5
l-0ctanol
10.3
10.3
8.3
1.6
5.8
Carboxylic acid
Acetic acid
10.1
10.5
7.1
3.9
6.6
Phenol
m-Cresol
10.2
11.1
8.8
2.5
6.3
Polyhydric alcohol
Ethylene glycol
14.6
16.1
8.3
5.4
12.7
Water
23.4
23.4
7.6
7.8
20.7
a25ฐC solubility parameters: 6 = Hildebrand parameter; Hansen para-
meters: - total; = dispersive; 6p = polar; 6h " hydrogen-
bonding. Metric unit MPa1/2 = 2.045 x (cal cm-3)l/2.
Source: Barton (1975).
55
-------
solubility parameters are among the paraffinic solvents, such as the normal
alkanes and many of the gasolines, and at the high end are the polar-type
liquids, such as the alcohols and water. Figure 7 illustrates the range of
individual types of common organics which are found in many leachates and thus
could be in contact with landfill or other containment linings.
Polymeric compositions also have solubility parameters which vary with
the molecular composition. The polymers that are used in the manufacture of
FMLs have a difference in their solubility parameter values. The distribu-
tion is narrower than that of the organics but tends to be in the same range
as that of most of the organics that may be found in leachates. Data for the
simple, usually lightly crosslinked and unfilled, compounds of polymers shown
in Figure 7 were taken from Barton 1983 and Burrell 1975. However, the com-
pounds were not FML compositions, which usually contain fillers and other
additives that affect swelling.
9 10 11 12 13 14 15 16 17 18
-1 1 1 I 1 I I i i
a) Different polymers
Teflon MR PP NBR
111 I
EPDM CR PVC
III
Silicone rubber CSPF Saran
I i | i
PECPE
I l |
b) Ranges by type of solvent
alcohols
j ethers ^
chlorinated solvents
eromatics
^ Bliphatics f [
ketones
ft)
.o c
5 ฐ4.
c) Distribution of common solvents
8 9 10 11 12 13 14 15 16 17 18
Solubility parameters 6, (cal cm-3)^
Figure 7. Solubility parameters of common solvents and polymers (data
from Barton, 1975, and Burrell, 1970).
56
-------
In the study conducted by Haxo et al (1988), a wide range of FMLs of
different compositions was investigated in a broad range of selected organics
and solvents. The organic liquids were selected to include as wide a range
of solubility parameters as possible, i.e., the dispersive, polar, and hydro-
gen-bonding parameters (Hansen parameters), which are the components of the
total Hildebrand solubility parameter. The various FMLs were immersed in the
different organic liquids and swelling was measured until equilibrium was
reached. Typical results are presented in Tables 26 and 27 for selected FMLs,
all of which were coircnercial products. The swelling data were then plotted
as a function of each of the Hansen solubility parameters (Barton, 1983) and
the best curves of the type shown 1n Figure 6 were obtained from the data by
computer analysis to yield the individual solubility parameters that are pre-
sented in Table 28, taken from Haxo et al (1988). In most cases, the data
agreed with the results in the literature for the Hildebrand solubility
parameter reported for the simple polymer compounds.
Swelling data, such as presented in Tables 26 and 27, can be used ef-
fectively for estimating the swelling of specific FMLs in specific neat or-
ganic liquids. More generally, they can be used to determine which solvents
are absorbed by a specific FML, either neat or a dissolved component in a
leachate, and are thus potentially aggressive to that FML. However, the
principal purpose of the data was to determine the solubility parameters of
the FML and to be able to determine whether a given organic would be absorbed,
but not for determining the magnitude of the absorption or swelling. As the
solubility parameters apply only to amorphous polymers or to the amorphous
phase of the partially crystalline polymers, the degree of crystal Unity and
other factors determine the magnitude of swelling. Overall, as discussed in
Matrecon (1988), these other factors include the following:
- Crystal 1inity content of the polymer.
- Degree of crosslinking of the polymer.
- Filler content of the compound.
- Plasticizer content of the compound.
- Soluble constituents in the compound.
- Molecular weight and Mk distribution of the basic polymer in the
compound.
In dilute aqueous solutions of organics, such as an MSW leachate, the
solubility parameters can be used to determined whether any of the dissolved
organics have soubility parameters which match or closely match the FML, and
therefore, would potentially partition to the FML and swell it.
Crystal 1inity of a polymer acts much like crosslInking to reduce the
ability of a polymer to dissolve. The crystalline domains of most polymers
do not absorb organics at normal ambient temperatures; at higher temper-
atures at which some crystals melt to become amorphous, swelling will
57
-------
TABLE 26. EQUILIBRIUM VOLUME SWELLING OF THE CPE, CSPE, EPDM, EVA, CR, AND PEL FML SPECIMENS'
IMMERSED IN 30 DIFFERENT ORGANICS AND IN WATER
H1 ldebrand
FML-
ฆpolymer/ID number^/extractables. X
solubility
CPE
CPE
CSPE
CSPE
EPDM
EVA
CR
PEL
PEL
parameter
335R
378R
169R
174R
232
308
168
316
323
Liquid
Co)
4.48c
7.94c
11.29^
7.15^
22.78ฎ
0.75e
11.23d
1.09e
*0.6
lsooctane (Ref. Fuel A)
7.0
10.1
5.83
1.50
8.71
68.6
28.3
0.96
7.25
0.86
n-Octane
7.6
12.5
6.40
1.77
12.9
86.8
34.1
0.61
8.27
2.88
Cyclohexane
8.2
51.0
16.8
119.5
99.7
125.9
97.4
30.8
19.0
4.46
Methyl isobutyl ketone
8.3
188.5
Df
38.4
40.8
5.20
3.67
56.1
38.3
10.5
Isoamyl acetate
8.4
200.0
Df
42.1
45.4
5.70
27.6
66.0
41.3
10.5
o-Xylene
8.8
Df
53.0
577.2
153.2
103.1
125.6
109.0
105.5
17.1
Diethyl carbonate
8.8
72.5
27.0
8.61
13.2
5.08
15.5
25.9
40.3
11.0
Dloctyl phthalate
8.9
218.1
141.7
32.0
29.2
4.16
12.6
73.4
18.0
0.72
Ethyl acetate
8.9
137.5
107.4
10.7
16.5
4.96
17.8
33.7
44.3
11.6
Methyl ethyl ketone
9.3
137.9
282.0
20.4
26.8
8.33
18.8
39.4
52.3
12.9
Trlchloroethylene
9.3
Df
62.7
435.0
Df
135.4
249.0
123.1
Df
25.1
Cyclohexanone
9.6
251.3
121.4
139.4
101.5
3.00
28.4
111.9
123.5
15.8
Acetone
9.8
56.3
85.0
7.56
13.3
0.88
14.5
10.1
33.5
11.2
Tetral 1n
9.8
Df
Df
353.5
180.9
68.6
82.2
180.9
280.3
24.7
Tetrachloroethylene
9.9
Df
45.2
468.3
160.8
146.0
181.8
105.4
70.9
14.5
2-ethyl-l-hexanol
9.9
3.96
8.58
1.52
3.12
4.83
15.2
5.27
16.7
1.51
Diethyl phthalate
10.0
125.2
72.7
9.57
14.0
0.50
6.28
33.9
38.0
3.22
Qulnoline
10.8
Df
Df
96.8
79.8
4.92
26.2
97.7
274.0
21.6
Cyclohexanol
10.9
2.96
7.91
2.40
5.65
7.46
9.19
2.32
16.7
2.40
N,N-d1nethylacetam1de
11.1
17.3
62.0
17.8
20.9
3.93
7.32
60.3
60.7
16.5
m-Cresol
11.1
48.5
23.1
14.8
19.6
2.72
55.5
27.2
Df
Df
Nltroethane
11.1
38.2
38.5
3.97
7.64
0.70
9.33
3.08
56.1
13.7
Benzyl alcohol
11.6
27.4
9.56
6.87
8.79
0.38
11.4
13.2
194.3
17.1
Furfuryl alcohol
11.9
6.00
1.66
3.82
5.39
0.24
4.54
1.99
174.6
15.3
1-Propanol
12.0
5.42
9.12
2.03
3.13
6.40
7.41
3.84
14.8
7.28
Butyrolactone
12.9
46.9
90.2
4.38
7.31
0.00
2.69
3.11
22.5
9.73
Propylene-1,2-carbonate
13.3
9.08
13.6
1.37
5.63
0.80
1.06
0.11
8.30
3.30
2-Pyrrolidone
13.9
38.8
107.1
12.2
11.2
1.29
1.97
14.9
14.6
4.67
Methanol
14.5
9.27
3.91
7.61
4.58
1.59
5.89
12.7
14.7
4.72
Ethylene glycol
16.1
3.64
5.33
2.06
3.22
0.49
1.55
1.76
2.42
1.67
Water
23.4
6.14
8.91
6.50
4.44
1.18
0.66
6.55
2.62
2.13
aCPE = chlorinated polyethylene; CSPE 1 chlorosulfonated polyethylene (169R Is potable grade, and 174R Is industrial grade);
EPDM = ethylene propylene rubber; EVA = ethylene vinyl acetate; CR * neoprene; PEL = polyester elastomer.
bR = fabric-reinforced.
cExtractab1es determined 1n accordance with Matrecon Test Method 2 using n-heptane as the solvent (Matrecon, 1988).
dExtractables determined 1n accordance with Matrecon Test Method 2 using acetone as the solvent (Matrecon, 1988).
eExtractables determined 1n accordance with Matrecon Test Method 2 using methyl ethyl ketone as the solvent (Matrecon, 1988).
fD 3 dissolved or disintegrated.
Source: Haxo et al (1988), pp 125 and 126.
-------
TABLE 27. EQUILIBRIUM VOLUME SWELLING OF PB, LDPE, LLDPE, HDPE, PVC, AND
PVC-E FHL SPECIMENS8 1MHERSED IN 30 DIFFERENT 0RGAN1CS AW) IN WATER
Liquid
Hildebrand
solubi1ity
parameter
Co)
FML-polvner/ID number/extractabl
es. X
PB
221
3.68b
LDPE
309
1.85b
LLDPE
284
0.65b
HDPE
263
i0.6b
HDPE
305
0.98b
PVC
153
34.57c
PVC-E
176R
9.13d
Isooctane (Ref. Fuel A)
7.0
25.0
10.1
11.4
4.36
7.89
21.7
3.25
n-Octane
7.6
26.3
13.1
14.2
7.68
9.68
19.9
2.70
Cyclohexane
8.2
61.6
23.1
24.5
11.2
12.8
19.9
14.2
Methyl isobutyl ketone
6.3
9.63
3.67
4.49
2.27
4.23
Dซ
Dซ
Isoamyl acetate
8.4
12.9
6.52
6.18
2.75
6.34
245.4
De
o-Xylene
8.8
28.9
19.9
20.4
11.6
14.3
7.92
84.0
Diethyl carbonate
8.8
6.44
4.56
2.61
2.15
2.69
11.8
42.6
Dioctyl phthalate
8.9
2.50
2.71
D.92
0.64
0.49
176.4
55.6
Ethyl acetate
8.9
7.30
3.01
3.04
2.61
2.61
147.5
De
Methyl ethyl ketone
9.3
6.53
2.72
4.06
2.17
2.55
De
De
Trichloroethylene
9.3
42.5
19.9
21.5
10.9
11.8
17.0
109.4
Cyclohexanone
9.6
9.56
5.04
4.36
1.40
4.88
Dซ
D*
Acetone
9.8
21.7
3.23
1.98
1.23
1.64
171.9
De
Tetralin
9.8
3.26
11.5
12.3
6.80
1.88
111.0
De
Tetrachloroethylene
9.9
17.5
25.0
25.5
13.7
13.5
2.64
64.1
2-ethyl-]-hexanol
9.9
1.46
4.21
1.59
0.32
1.06
12.8
8.34
Diethyl phthalate
10.0
0.80
0.81
1.36
0.45
1.37
86.58
56.3
Quinoline
10.8
5.22
3.67
4.06
1.79
4.22
D*
De
Cyclohexanol
10.9
2.07
2.07
1.71
0.40
1.21
11.2
9.61
N,N-dimethylacetam1de
11.1
1.97
2.44
3.93
0.52
2.47
De
De
m-Cresol
11.1
1.60
2.17
1.59
0.79
2.39
7.65
93.1
Nitroethane
11.1
2.47
1.12
0.94
0.60
0.90
44.3
De
Benzyl alcohol
11.6
0.85
0.76
0.44
0.17
0.91
11.6
52.2
Furfuryl alcohol
11.9
0.23
0.20
0.16
0.70
0.39
13.1
23.1
1-Propanol
12.0
1.15
1.01
1.D5
0.68
1.15
19.0
5.04
Butyrolactone
12.9
0.52
0.26
0.66
0.16
0.71
D*
53.4
Propylene-1,2-carbonate
13.3
0.95
0.52
0.75
0.24
0.24
11.9
16.1
2-PyrrolIdone
13.9
0.61
0.79
0.79
0.16
0.90
277.7
42.9
Methanol
14.5
0.96
3.46
1.74
1.09
2.60
17.7
2.98
Ethylene glycol
16.1
0.69
0.56
0.41
0.24
0.39
3.43
3.12
Water
23.4
1.53
4.61
1.54
0.23
1.51
1.56
2.32
4PB = polybutylene; LDPE = low-density polyethylene; LLDPE ฆ linear low-density polyethylene; HDPE * high-
density polyethylene; PVC ฆ polyvinyl chloride; PVC-E - polyvinyl chloride elasticl2ed; R ซ fabric-reinforced.
bExtractables determined 1n accordance with Hatrecon Test Method 2 using methyl ethyl ketone as the solvent
(Matrecon, 1986).
cExtractables determined in accordance with Hatrecon Test Method 2 using 2:1 mixture of CCI4 and CH3OH
as the solvent (Hatrecon, 1988).
dExtractables determined 1n accordance with Hatrecon Test Hethod 2 using CH3OH as the solvent (Hatrecon, 1988).
eD * dissolved or disintegrated.
Source: Naxo et al (1988), pp 126 and 127.
59
-------
increase. Highly crystalline polymers, such as HDPE, will swell slightly in
gasoline but will not dissolve, even though the HDPE and the gasoline are both
hydrocarbons and have similar solubility parameters.
TABLE 28. SOLUBILITY PARAMETER VALUES FOR FMLS
(cal/cm3)l/2
Polymer
^0
ซd
ซp
ซh
ซta
Chlorinated polyethylene'3
9.27
9.39
7.99
9.23
3.23
2.06
3.15
2.50
9.18
9.78
Chlorosulfonated polyethylene*5
9.52
9.39
9.13
8.91
0.93
1.76
2.60
1.52
9.54
9.21
Epichlorohydrin rubber
11.35
9.23
5.00
4.56
11.45
Ethylene propylene rubber
8.91
9.07
0.64
0.65
9.12
Ethylene vinyl acetate
9.39
8.96
0.88
0.98
9.06
Neoprene
9.52
9.29
1.72
1.95
9.65
Polyester elastomer^
10.61
11.35
8.91
8.91
2.06
4.02
5.32
4.12
10.58
10.61
Polybutylene
7.69
7.49
0.05
0.43
7.50
Polyethylene:
Low-density
Linear low-density
High-densityb
7.81
8.17
7.93
7.56
9.45
9.02
8.05
8.50
0.05
0.05
0.05
0.05
0.11
0.43
0.98
0.54
9.45
9.03
8.11
8.52
Polyurethane
11.59
8.86
3.82
5.64
11.18
Polyvinyl chloride
10.13
7.99
5.39
3.91
10.40
Elasticized polyvinyl chloride
9.76
9.34
4.26
3.47
10.84
Polyvinyl chloride (oil-resistant)
9.64
7.88
4.41
4.23
9.97
a5t - + ซp ~
^Two different FMLs based on the same type of polymer.
Source: Haxo et al (1988).
60
-------
Crosslinking of a noncrystalline polymer or a rubber reduces the ability
of the polymer to swell in a liquid which has solubility parameters similar
to those of the polymer. The amount of swelling of a crosslinked polymer in
a good solvent for the raw polymer can be used as a measure of the degree of
crosslinking: the greater the crosslinking, the less the swelling.
The presence of additives, such as fillers and plasticizers, in the
FML composition can affect the magnitude of swelling. A particulate filler
used in the compound recipe (e.g. carbon black, silica, or clay), which does
not swell, is often added to reduce swelling of a polymeric composition.
As with the crystalline domains in semi crystal 1ine polymers, nonporous
particulate fillers such as those listed do not absorb organics. Monomeric
plasticizers, which are similar to oils and are used to soften hard resins,
are generally extractable by organic solvents and most are only slightly
extractable by water. On the other hand, some plasticizers are polymeric
and are only slightly extractable by solvents in which the polymeric plas-
ticizers are soluble.
Rubber and plastic compounds may contain minor amounts of water-soluble
inorganic salts which enter the compound via the polymer itself, e.g. cata-
lyst traces, salt used in flocculation, etc., and via small amounts in the
various compounding ingredients, e.g. many of the non-black fillers contain
small amounts of water-soluble constituents. These water-soluble salts can
cause swelling by diffusion of water into the mass by the driving force of
osmosis.
Increasing the molecular weight of a polymer generally reduces its solu-
bility as it will contain less lower molecular weight polymer which can be
extracted by organics having solubility parameters that are near those of
the polymer.
The importance of the degree of crystal 1inity on the swelling of an FML
can be illustrated by considering the data in Tables 26 and 27 for EPDM and
the four sets of data on the polyethylenes, which increase in crystal Unity
for LDPE, LLDPE, and the two HDPEs, which have quite similar solubility
parameters. The EPDM is an amorphous rubber compound with some crosslinking
and contains fillers, but is noncrystalline. Swelling by solvents, such as
cyclohexane, o-xylene, trichloroethylene, and tetrachloroethylene, which
have nearly matching solubility parameters, decreased from about 130% for
EPDM, to 20 to 25% for LDPE/LLDPE, and to about 12% for the two HDPEs. The
last two are 50 to 60% crystalline.
Additional data on the absorption of organics from dilute aqueous solu-
tions need to be developed, as it appears that detailed analytical knowledge
of a leachate composition could indicate the presence of organics which would
be absorbed by a given FML and which, in sufficient concentration, might be
damaging to the FML.
61
-------
DISCUSSION
On reviewing the information obtained in the literature survey, it was
quite apparent that a number of areas remained which needed further clar-
ification and study before specific recommendations could be made as to
the type and amount of testing required to assess the long-term compatibil-
ity of a specific FML with a specific MSW leachate and as to whether blanket
approval without compatibility testing can be given to an FML for use in a
lining system for a waste storage or disposal facility. Some of the areas
that needed additional information and analysis were:
- Expansion of the experimental data based on the partitioning of
organics from dilute aqueous solutions of organics and inorganics,
such as are in MSW leachates, to FMLs at various temperatures.
Additional FMLs and a wide range of organics and leachates should
be explored.
- Expansion of data on the rates of absorption of organics from dilute
aqueous solutions of organics at different temperatures. More than
four months would probably be required to reach an equilibrium ab-
sorption of the organic by an FML from dilute solutions.
- Expansion of the data base on the MSW leachate compositions with
respect to those constituents that are aggressive to FMLs, i.e. those
constituents which are absorbed by the FML.
- Development of means of chemically stabilizing an MSW leachate for
more than four months at temperatures up to 50ฐC in order to simulate
in-service condition of the leachate for laboratory compatibility
tests.
- Assessment of the effects of water absorption on the absorption of
organics by FMLs from dilute aqueous solutions; investigate inter-
action of organic constituents in the leachate with the water and
with the inorganic consitituents.
- Determination of the rates of loss of plasticizers from plasticized
FMLs to dilute aqueous solutions of organics.
- Assessment of the effects of loss of antioxidants from FMLs to the
leachate or dilute aqueous solutions of organics on properties of
FMLs.
Some experimental work was undertaken with respect to partitioning of
several organics to different FMLs. This work is reported in Section 6.
62
-------
SECTION 6
EXPERIMENTAL WORK
INTRODUCTION
Inasmuch as only a limited amount of experimental work could be performed
in this study, it was decided to measure the absorption'of three organics by
different FMLs from a dilute aqueous solution and to assess the effect on the
tensile properties of the FMLs. The aqueous solution would simulate a leach-
ate with three dissolved organics that would commonly be found in MSW leach-
ates. The transfer or partitioning of the organics from the water to the FMLs
would be followed by GC analysis of the solution.
Specimens of FMLs based on four different polymers, including linear low-
density polyethylene (LLDPE), polyvinyl chloride (PVC), chlorinated polyethyl-
ene (CPE), and a fabric-reinforced low-water absorption chlorosulfonated
polyethylene (CSPE-R), were placed in vapor-tight cells filled with a dilute,
unsaturated aqueous solution containing three different organics. The chang-
ing concentrations of the organics in the aqueous solutions were monitored
until they had become relatively constant, the cells were opened, and the
FML specimens were analyzed to determine the concentration of the organics.
Analyses for organics in both the solutions and the FMLs were performed
using GC procedures. Experimental details and results are presented in this
section.
EXPERIMENTAL DETAILS
Immersion Test Cells
The immersion test cells were sealed 8-oz jars, each having a septum
in the cover through which samplings of the solutions could be taken. This
type of cell, illustrated in Figure 8, was used in the work described by
Haxo et al (1988) and Haxo (1988). Small stainless steel wire frames, from
which specimens of the FMLs were suspended, were placed in the cells.
Selection of Volatile Organics
For this study, three volatile organics, representing a range of chemical
characteristics and solubility parameters, were selected. It was desired to
have a volatile organic containing oxygen, a volatile that was a chlorinated
solvent, and a volatile that was an aromatic. The three organics were methyl
ethyl ketone (MEK), trichloroethylene (TCE), and toluene, all of which have
63
-------
been found in currently generated MSW leachates. The specific properties of
these organics are given in Table 29.
Teflon
Septum
Teflon-lined
Screw cap
Swagelock
Assembly
Jar with
ground and
polished
edge
Nut
TOP ASSEMBLY
6 oz JAR
Figure 8. Schematic of the immersion test cell with septum for
withdrawing samples of aqueous solution for GC analysis.
TABLE 29. ORGANICS USED IN ABSORPTION EXPERIMENTS WITH DILUTE AQUEOUS SOLUTIONS
Vapor Solu-
Mole- Density Boiling pressure Solubility bility
cular at 20ฐC, point, at 25ฐC, parameters3 in water,
Organic weight g/cm3 ฐc mm Hg 60 6^ 6n 6^ mg/L^ CASN0C
Toluene 92.13 0.866 110.6 31.96 8.9 8.8 0.7 1.0 515 108-86-3
Trichloroethylene 31.40 1.476 87.2 80.30 9.2 8.8 1.5 2.6 1,100 79-01-6
Methyl ethyl ketone 72.10 0.805 79.6 100.0 9.3 7.8 4.4 2.5 240,000 78-93-6
aBarton (1983).
bRiddick and Bunger (1970).
cChemical Abstract Services' number.
Analysis of the Dilute Aqueous Solutions and Vapors of Organics
A Perkin-Elmer Sigma Three Series GC with a flame ionization detector was
used to analyze for the organics in the aqueous solutions and for the organics
absorbed by the FMLs.
64
-------
After reviewing the performance of several GC columns for the separation
and measurement of the organics in dilute aqueous solutions and for headspace
analysis of the FMLs, it was decided to use an open-capillary column coated
with polyethylene glycol. The conditions and a description of the GC analy-
sis are presented in Table 30. Appropriate calibration curves were developed
for each of the three organics in aqueous solutions and as vapors in headspace
containers.
TABLE 30. GAS CHROMATOGRAPHY CONDITIONS FOR AQUEOUS
SOLUTION AND VAPOR ANALYSIS
Condition
Setting
Detector range
Injector and detector temperature
Initial temperature
Initial holding time
Final temperature
Final holding time
Temperature program rate
Detector
Column^
Chart speed
Carrier
Specimen size:
Liquid
Vapor from headspace
Attenuation
x 10
250ฐC
60ฐC
1 min.
120ฐCa
1 min.
20ฐC/min.
Flame ionization:
H? 30 cc/min.
O2 40 cc/min.
Polyethylene glycol coated
fused silica open tube
(FS0T) capillary: 0.53 mm
in diameter and 15 m in
length
30 min./hour
Helium, 10 cc/min.
1 uL
100 uL
32 (for 500 ppm concentration)
down to 4 (for low concentration)
aCan vary with the solvent mixture from 120ฐC to 260ฐC, the maximum
temperature for the column.
^Trade name Superox (Altec), Megabore DB WAX (J and W).
65
-------
The calibration curves for the solutions were determined by injecting
1 uL of various solutions of known concentrations of the different organics
into the GC column. Injections of each standard were performed five times to
ensure reproducibility of injection techniques. Standard deviation was 2% of
the mean values. The concentrations of the organics in the immersion liquid
were calculated by comparing peak height values with calibration curves.
The calibration curves for the headspace GC analyses were prepared by
analyzing a specific volume of vapor (either 100 uL or 400 yL) from headspace
cans injected with different volumes of organics. These calibration curves
are illustrated in Figures 9 and 10.
6000
t 1 1 r
C
5
m
c
M
5400 -
4800
4200
3600
Toluene
= 3000
o
ot
X
Jt
N
Q.
2400 -
1800
1200 -
600
250 500
Concentration In ppm
750
Figure 9. Calibration curve for toluene, MEK, and TCE in aqueous solutions.
Peak height x attenuation is plotted against the concentration
(in ppm).
66
-------
16,000
Toluene
c
o
12,000
CO
3
C
<
X
8
m
8000
MEK
o>
X
-------
were detected by the GC in the sampled vapors. The amounts for each organic
in each heat were summed to yield a total for that organic in the sample.
ANALYSIS AND TESTING OF THE FMLS SELECTED FOR THIS STUDY
The four FMLs included in this study were:
- Chlorinated polyethylene (CPE).
- Fabric-reinforced low-water absorption chlorosulfonated polyethylene
(CSPE-R).
- Linear low-density polyethylene (LLDPE).
- Polyvinyl chloride (PVC).
Samples of these FMLs were received from the EPA Technical Project Monitor.
Table 31 lists the properties and test methods that were used in measuring
the properties of the FMLs. Table 32 presents the analytical and physical
properties of the unreinforced FMLs, and Table 33 presents analytical results
of the testing of the fabric-reinforced CSPE FML. These four FMLs are repre-
sentative of the respective types of FMLs and were judged to be satisfactory
for use in the experimental work.
IMMERSION OF SPECIMENS OF FMLS IN DILUTE AQUEOUS SOLUTIONS OF 0RGAN1CS
A series of three immersion experiments were conducted to determine the
absorption by FMLs of organics from dilute aqueous solutions. These experi-
ments were designed to simulate FMLs in contact with MSW leachate. The ob-
jectives were to determine weight increase, the amount of organics absorbed,
and the effect of the swelling on tensile properties of the FMLs.
Immersion of a PVC FML in a Dilute Aqueous Solution of Organics--
Experiment 1
In an exploratory first experiment, the three volatile solvents, MEK,
TCE, and toluene, were dissolved at low concentrations (500 ppm) in D1 water
and a sample of the PVC FML was placed in the solution in the immersion test
cell (Figure 8). The results of this initial experiment at equilibrium
indicated that the MEK remained in the water, whereas both the TCE and the
toluene partitioned to the PVC. This was verified by the headspace GC analy-
sis of the PVC which showed that the amount of MEK that was in the PVC was
only a fraction of a percent, whereas substantial amounts of toluene and TCE
were absorbed by the PVC. It was observed, however, that not all of the
solvents were released in the headspace GC analysis from the PVC FML on
heating in the headspace can, even at 150ฐC. A thermogravimetric analysis
(TGA) on the exposed PVC after headspace GC analysis was then performed. It
was found that, at about 200ฐC, additional volatiles were removed, confirming
the fact that all of the organics were not removed in the headspace GC heat-
ing. The results of the TGA are presented in Table 34.
68
-------
TABLE 31. PROPERTIES AND METHODS FOR TESTING FOUR
FMLS IN MUNICIPAL SOLID WASTE LEACHATE COMPATIBILITY STUDY
FMLs
Property
Test method3
PVC
LLDPE
CPE CSPE-Rb
Analytical properties
Volatiles content
Matrecon, 1988
(Appendix G)
X
X
X
X
Extractables content
Matrecon, 1988
(Appendix E)
X
X
X
X
Specific gravity
ASTM D792, Method A
X
X
X
X
Carbon black content
Thermal gravimetric
analysi s
f
X
4
ft ft
Physical properties
Tensile properties:
Tensile at yield
ASTM D638
X
Elongation at yield
ASTM D638
X
Tensile at break
ASTM D638/D412
X
X
X
Elongation at break
ASTM D638/D412
X
X
X
Stress at 100% elongation
ASTM D638/D412
X
X
X
Stress at 200% elongation
ASTM D638/D412
X
X
X
Grab tensile strength
ASTM D751
X
Grab elongation
ASTM D751
ป
X
Tear strength
ASTM D1004
X
X
X
Puncture resistance
FTMS 101C, Method
2065
FTMS 101C, Method
2031
X
X
X
ป
X
Hydrostatic resistance
ASTM D751
X
X
X
X
Ply adhesion
ASTM D413
ซ
X
aASTM = American Society for Testing and Materials;
Method Standards.
FTMS
= Federal
Test
bR = fabric-reinforced.
69
-------
TABLE 32. ANALYTICAL AND PHYSICAL PROPERTIES OF UNREINFORCED FMLS
Property
Analytical properties
Volatiles at 105ฑ2ฐC, %
Extractables, %
Ash, %
Carbon black content, %
Specific gravity of FML
Density of polyethylene, g/cm^
Physical properties
Thickness, mil
Tensile properties:
Tensile at yield, psi
Elongation at yield, psi
Tensile at break, psi
Elongation at break, %
Stress at 100% elongation, psi
Stress at 200% elongation, psi
Tear strength, ppi
Hydrostatic resistance, psi
Puncture Resistance
Thickness, mil
Stress, lb
Elongation, in.
FMLsa
Di recti on
PVC
LLDPE
CPE
of test
579
580
581
0.46
0.14
0.14
35.23b
2.28c
14.30<
1.65
2.27
ฆ
1.243
0.945
1.349
0.936
9 m 9
20.0
20.2
30.6
Machine
2340
Transverse
2550
Machine
~
20
Transverse
~
15
Machine
2990
3985
1785
Transverse
2815
3650
1550
Machine
335
875
325
Transverse
345
920
495
Machine
1435
1925
1255
Transverse
1295
1865
605
Machine
2100
1965
1475
Transverse
1895
1875
780
Machine
360
775
280
Transverse
345
715
215
72
140
98
20.0
20.4
30.5
31.1
32.7
41.3
0.69
1.00
0.99
aPVC = polyvinyl chloride; LLDPE = linear low-density polyethylene;
CPE * chlorinated polyethylene; numbers = Matrecon identification number.
^Extraction solvent: 2:1 blend of carbon tetrachloride and methyl alcohol.
cExtraction solvent: methyl ethyl ketone.
dn-Heptane.
70
-------
TABLE 33. ANALYTICAL AND PHYSICAL PROPERTIES OF
FABRIC-REINFORCED CSPE FMLa
Property
Di recti on
of test
Values
Analytical properties
Volatiles, %
Extractables, %
Specific gravity
0.24
6.15
1.518
Physical properties
Thickness, mil
37.9
Tensile properties^:
Breaking strength of fabric, lb
Machine
Transverse
265
310
Elongation of fabric, %
Machine
Transverse
20
27
Breaking strength of rubber, lb
Machine
Transverse
180
265
Elongation of rubber, %
Machine
Transverse
60
80
Ply adhesion, ppi
Machi ne
Transverse
9
10
Hydrostatic resistance, psi
418
Puncture resistance, lb
186
aMatrecon Identification Number 582.
bGrab test.
6.4.2 Immersion of Specimens of PVC, LLDPE, CPE, and CSPE-R in
Cells Containing a Dilute Aqueous Solution of MEK,
Toluene, and TCEExperiment 2
In the second experiment, four immersion test cells were filled with
an aqueous solution containing a mixture of 500 ppm each of MEK, TCE, and
toluene. Specimens of each of the four FMLs in the study were immersed in
separate cells and the concentrations of the volatile organics in each cell
were followed by GC analysis. In all cases, the concentrations of the MEK
showed little change; thus, little partitioning of the MEK from the water
phase to the FMLs had occurred. On the other hand, the toluene and TCE
71
-------
showed significant drops in concentration in the water, and thus showed
partitioning from the water to the FMLs (Table 35). These results basically
follow the distribution results reported for the HDPE FML in Haxo et al
(1988).
TABLE 34. THERMOGRAVIMETRIC ANALYSIS3 OF PVC FML AFTER
IMMERSION AND HEADSPACE GC ANALYSISEXPERIMENT 1
Parameter
PVC 579
(unexposed)
PVC 579
(exposed15)
Volatiles at 110ฐC, %
0
0.3
Loss between 110 and
200ฐC, %
0
0.4
Polymer loss as HC1 +
plasticizer, %
72.0
72.0
Residual polymer, %
17.5
17.3
Char + carbon black, %
8.85
8.8
Ash, %
1.65
1.2
Total
100.0
100.0
^onset* ฐC
280
290
Tmax-1ป
332
332
Tmax-2ป ฐC
518
520
Specimen weight, mg
6.468
7.205
TGA scan number
780
779
aThermogravimetric analysis test conditions: Temperature
raised from 30ฐC to 110ฐC at 40ฐC min.-l in N2 and held
until no change 1n weight; temperature raised from 110ฐ
to 600ฐC at 10ฐC cm"* in N2 and held until no change
in weight; O2/N2 introduced and temperature raised from
600ฐ to 700ฐC at 10ฐC min.-l and held at 700ฐC until
no change in weight. The first two holding times for
the test of the unexposed PVC were 8 and 13 minutes,
respectively, and for the exposed PVC were 10 and 20
minutes.
^Exposure: In the headspace GC analysis specimens
underwent 3 heatings of 1 hour at 105ฐC and 1 heating
for 1 hour at 150ฐC before the TGA analysis.
72
-------
TABLE 35. ABSORPTION OF ORGANICS BY FMLS? IMMERSED FOR TWO MONTHS IN
DILUTE^3 AQUEOUS SOLUTIONS CONTAINING A MIXTURE OF ORGANICScEXPERIMENT 2
Parameter
PVC
579
LLDPE
580
CPE
581
CSPE-R
582
Contents of cell at beginning
of experiment
Amount of water in cell, g
225.5
226.6
228.4
225.2
Amount of organicsc in cell:
MEK, mg
TCE, mg
Toluene, mg
112.8
112.8
112.8
113.3
113.3
113.3
114.2
114.2
114.2
112.6
112.6
112.6
Total, mg
338.4
339.9
. 342.6
337.8
GC analysis of aqueous solution
at end of experiment
Amount of organics:
MEK, mg
TCE, mg
Toluene, mg
112.5
48.3
39.2
110.1
87.5
80.4
91.4
41.6
27.9
111
46.6
38.1
Total, mg
200.0
278.0
160.9
195.7
Concentration of organics:
MEK, ppm
TCE, ppm
Toluene, ppm
500
214
174
486
386
355
400
182
122
493
207
169
Weights of FML specimen
Original weight, g
3.4580
2.5337
5.4670
6.1601
Weight at end of immersion:
Swollen weight, g
Weight gain, g
Weight gain, %
3.668
0.210
6.1
2.626
0.093
3.7
6.246
0.779
14.2
6.702
0.542
8.8
Headspace analysis of
swollen FMl specimen
Amount in swollen FML
specimen:
MEK, mg
TCE, mg
Toluene, mg
1.35
54.0
55.6
0.08
36.3
44.5
1.16
63.7
65.5
0.55
34.3
38.8
Total, mg
110.95
80.88
130.36
continued
73.65
73
-------
TABLE 35. (continued)
PVC LLDPE CPE CSPE-R
Parameter 579 580 581 582
% of original weight
of FML specimen 3.21 3.19 2.38 1.20
Concentration of organics
in swollen FML specimen
-------
The cells were opened after two months of equilibration and the respec-
tive exposed specimens of FMLs were recovered arid analyzed by headspace GC
for the volatile organics. Also, the weights of the specimens were measured
at the time of removal from the cells and after headspace GC. The results
reported in Table 35 show that there was a significant weight gain by each of
the specimens; however, all of the weight gains could not be attributed to
the absorption of the organics, indicating (1) that considerable water had
also been absorbed by the specimens, or (2) that the headspace GC did not
recover all of the absorbed organics. Regardless, the results do show a
large partitioning of the organics from the water into the FMLs; furthermore,
they show that the FMLs varied considerably in the amounts of the different
organics.
Table 36 presents the results of the headspace GC showing the amount of
each organic that was recovered at each of the five heating steps that were
used. The first four steps were performed at 105ฐC. The results indicate,
particularly for toluene, that all of this organic had not been released from
the FML during one hour heating at 150ฐC.
Immersion of FMLs in Dilute Aqueous Solution of Orqanics--Experiment 3
To confirm the results of Experiment 2 and to measure the effects on
tensile properties of the FMLs, Experiment 2 was repeated using two precut
tensile test specimens, one cut in the machine direction and one 1n the
transverse direction, plus a headspace GC specimen for each FML in the re-
spective cells. The total weights of the FML specimens immersed in each cell
were the same as the specimens immersed in Experiment 2. The analytical
results of Experiment 3 are reported in Table 37. The tensile specimens were
weighed and tested with the results reported in Table 38. Though the equili-
bration time was shorter than that used in Experiment 2, these results essen-
tially confirm those of Experiment 2 and show that, even at low concentrations
of organics, the total absorptions and the absorptions of some of the organics
are significant. Also, the effects on the tensile properties showed losses in
tensile strengths and stresses at 100 and 200% elongation of up to 25-30%.
ANALYSIS OF FMLS USED IN NATIONAL SANITATION FOUNDATION
CHEMICAL COMPATIBILITY STUDY
In order to aid in the analysis of the National Sanitation Foundation
(NSF) data discussed in Section 5 (Bellen et al, 1987), the HDPE, PVC, CPE,
and unreinforced CSPE-LW FMLs were analyzed for extractables and ash contents.
These data permited a calculation of the fraction of each compound that was
"polymeric." Samples of the FMLs were received from NSF through arrangements
made by the EPA Technical Project Monitor. Results of the analyses are re-
ported in Table 39. They indicate that all of the FMLs, except the poly-
ethylene, contained measurable amounts of extractables, probably plasticizers.
They also had significant ash contents, which indicated relatively high non-
black filler contents, particularly in the cases of the CSPE-LW FMLs. The
results also show that the two CSPE-LW samples received from NSF are the
same.
75
-------
TABLE 36. HEADSPACE ANALYSIS OF EXPOSED FMLSaEXPERIMENT 2
PVC
579
LLDPE
580
CPE
581
CSPE-R
582
MEK
TCE
Tol
MEK
TCE
Tol
MEK
TCE
Tol
MEK
TCE
Tol
Organics recovered during
each heat, mg:
Heat n (1 hr, 105ฐC)
0.96
37.0
30.3
0.08
32.0
36.5
0.84
46.2
38.5
0.45
24.7
21.1
Heat n (1 hr, 105ฐC)
0.31
12.0
15.4
0
3.8
6.2
0.24
12.4
16.5
0.10
7.5
12.0
Heat n (1 hr, 105ฐC)
0.08
4.1
7.2
0
0.54
1.53
0.08
4.2
7.6
0
1.8
4.4
Heat *4 (15 hrs, 105ฐC)
0.00
0.54
1.40
0
0
0.20
0
0.70
1.80
0
0.19
0.80
Heat *5 (1 hr, 150ฐC)
0.00
0.37
1.30
0
0
0.08
0
0.20
1.10
0
0.12
0.50
Total organic recovered, mg
1.35
54.0
55.6
0.08
36.3
44.5
1.16
63.7
65.5
0.55
34.3
38.8
% of initial liner weight
0.04
1.56
1.61
0.003
1.43
1.76
0.02
1.17
1.20
0.01
0.56
0.63
aPVC = polyvinyl chloride; LLDPE = linear low-density polyethylene; CPE = chlorinated polyethylene;
CSPE-R = chlorosulfonated polyethylene (fabric-reinforced); number is Matrecon's liner identification
number; MEK = methyl ethylene ketone; TCE = trichloroethylene; Tol = toluene.
-------
TABLE 37. ABSORPTION OF ORGANICS BY FMLSa IMMERSED FOR TWO WEEKS IN
DILUTE^ AQUEOUS SOLUTIONS CONTAINING A MIXTURE OF ORGANICScEXPERIMENT 3
Parameter
PVC
579
LLDPE
580
CPE
581
CSPE-R
582
Contents of cell at begin-
ning of experiment
Amount of water in cell, g
230
230
230
230
Amount of organicsc in cell:
MEK, mg
TCE, mg
Toluene, mg
115
115
115
115
115
115
115
115
115
115
115
115
Total, mg
345
345
345
345
GC analysis of aqueous solution
at end of experiment
Amount of organics:
MEK, mg
TCE, mg
Toluene, mg
115.0
36.7
23.2
113.8
64.6
55.9
109.9
28.8
17.7
112.7
35.4
30.5
Total, mg
174.9
234.3
156.4
178.6
Concentration of organics:
MEK, ppm
TCE, ppm
Toluene, ppm
508
155
101
495
281
243
478
125
77
490
154
89
Weight of FML specimens'1
Original weight:
Specimen 1, g
Specimen 2, g
Specimen 3, g
1.1279
1.1278
1.2051
0.9170
0.9049
0.7220
1.8591
1.8680
1.7227
4.4514
1.6938
Total, g
3.4608
2.5438
5.4498
6.1452
Weight at end of immersion:
Specimen 1, g
Specimen 2, g
Specimen 3, g
1.2017
1.2029
1.2797
0.9551
0.9425
0.7528
2.0162
2.016
1.871
4.7638
1.81*63
Total, g
3.6843
2.6505
5.9032
6.5801
Gain in weight, g
% Gain in weight
0.2235
6.46
0.1067
4.20
0.4534
8.32
0.4349
7.08
Headspace GC analysis of
swollen FML Specimen 3
Amount in FML:
MEK, mg
TCE, mg
Toluene, mg
0.39
16.41
22.72
0.02
6.22
8.33
0.62
24.13
28.28
0.06
5.84
9.10
Total, mg
39.52
14.57
53.03
15.00
continued . . .
77
-------
TABLE 37. (continued)
PVC
LLDPE
CPE
CSPE-R
Parameter
579
580
581
582
Organics in FML Specimens 1-3
immersed in cellse
MEK, mg
1.12
0.07
1.96
0.22
TCE, mg
47.16
21.90
73.36
21.19
Toluene, mg
65.29
29.33
89.49
33.02
Total, mg
113.56
51.30
167.82
54.43
Concentration of organics
in Specimens 1-3:
MEK, ppm
300
30
330
30
TCE, ppm
12,800
8,260
12,900
3,220
Toluene, ppm
17,700
11,100
15,100
5,000
% of original weight
of FML specimens
3.28
2.02
3.08
0.89
Total amount of organics in
eel 1e at end of experiment
MEK, mg
116.1
113.9
111.9
112.7
TCE, mg
83.9
86.5
102.2
56.6
Toluene, mg
88.5
85.2
107.2
53.6
Total, mg
288.5
285.6
321.3
194.1
Percent of original
amount in cell
MEK, %
>100
99.0
97.3
98.2
TCE, %
73.0
75.2
88.8
49.2
Toluene, %
77.0
74.1
93.2
46.7
Total, %
83.6
82.8
93.1
56.3
Distribution coefficient
(cfml/ch2o):
MEK
0.6
0.06
0.69
0.06
TCE
83
29
103
21
Toluene
176
46
196
56
aPVC = polyvinyl chloride; LLDPE = linear low-density polyethylene;
CPE = chlorinated polyethylene; CSPE-R ซ chlorosulfonated polyethylene
(fabric-reinforced).
bMethyl ethyl ketone (MEK), trichloroethylene (TCE), and toluene.
cInitial concentration of each organic was 500 ppm.
^Specimens 1 and 2 were dumbbell specimens for tensile test; Specimen 3
was for headspace GC analysis.
esum of organics in water and in the FML specimens.
78
-------
TABLE 38. TENSILE PROPERTIES OF FHLS AFTER IMMERSION IN DILUTE SOLUTIONS OF MEK, TCE, AND TOLUENE IN SEALED CELLS3EXPERIMENT 3
hfC M LLOPE 580 CPE S81 CSPE-R 582
Parameter Original Exposed Retention, * Original Exposed Retention, * Original Exposed Retention, * Original Exposed Retention, X
Height Increase
...
6.46*
...
...
4.19*
...
...
8.61*
...
7.12*
...
Headspace GC analyses:
MEK
TCE
Toluene
Total
...
0.03*
1.36*
1.89*
r?i*
...
0.003*
0.86*
1.15*
2.62*
...
...
0.06*
1.40*
1.64*
7708*
...
0.004*
0.34*
0.54*
o$*
...
Thickness
Direc-
tion
of
test
...
19.0 mil
22.0 ml 1
30.5 mil
Tensile at yield
M
T
...
:::
2340 psl
2550 psl
2090 ps1
2020 psl
89.3
79.2
...
.
Elongation at
yield
T
20*
15*
20*
15*
100
100
...
.
...
...
Tensile at
fabric break
T
...
...
...
.
...
166 ppl
136 ppl
81.9
Elongation at
fabric break
T
...
...
...
...
...
25*
30*
92.3
Tensile at break
T
2990 ps1
2815 psl
2620 psl
2525 psl
87.6
89.7
3985 psl
3650 psl
3080 psl
3150 ps1
77.3
86.3
1785 psl
1550 psl
1475 psl
1085 psl
8
6
302 ppl
288 PPI
96
Elongation at
break
T
335*
345*
325*
350*
97.0
101.2
875*
920*
775*
925*
88.6
100.5
325*
495*
350*
450*
10
9
32*
22.5*
70.3
Stress at 100*
elongation
T
1435 psl
1295 psl
1220 psl
1305 psl
85.1
100.8
1925 ps1
1865 psl
1765 psl
1476 ps1
91.6
79.1
1255 psl
605 psl
870 psl
573 psl
6
9
22 ppl
...
Stress at 200*
elongation
T
2100 psl
1895 psl
1810 psl
1935 psl
86.2
102.2
1965 psl
1875 psl
1735 psl
1525 psl
88.2
81.4
1475 psl
780 psl
1095 psl
775 psl
7
9
...
23 ppl
...
apvc ป polyvinyl chloride; LLDPE ซ linear low-density polyethylene; CPE * chlorinated polyethylene; CSPE-R = chlorosulfonated polyethylene (fabric-
reinforced); number 1s Matrecon's liner Identification number; MEK = methyl ethylene ketone; TCE = trlchloroethylene.
-------
TABLE 39. ANALYSIS OF FMLS USED IN NSF CHEMICAL COMPATIBILITY STUDY3
HDPE
PVC
CPE
CSPE-LW
CSPE-L*
Parameter
629
630
631
632
633
Specific gravity
0.955
1.260
1.356
1.469
1.506
NSF data3
0.951
1.260
1.358
Extractables, %
Solvent
MEK
CC14:CH3OH
n-Heptane
acetone
acetone
2:1
Sample 1
1.51
33.85
8.60
5.43
4.40
Sample 2
1.43
34.89
7.66
4.91
5.77
Average
1.47
34.37
8.13
5.17
5.09
Thermogravimetric
analysis'3:
Volatiles, %
0.6
0.4
0.9
0.4
0
Polymer loss as HC1 +
piasticizers, %
qc n
69.4
41.1
17.1
16.8
Residual polymer, %
yo ปu
16.4
38.0
33.3
33.2
Char + carbon black, %
3.3
8.8
7.5
18.2
18.0
Ash, %
0.1
4.8
12.5
31.0
32.0
Total
100.0
99.8
100.0
100.0
100.0
Tonset> ฐC
466
273
300
290
304
Tmax-1ซ ฐC
492
311
350
331
337
Tmax-2ป ฐC
477
508
480
500
Specimen weight, mg
6.247
8.166
6.493
7.830
5.472
TGA scan number
799
800
798
801
797
Polymer content of FML,
% by weight
96.0
52
74
46
46
aBellen et al (1987).
bThermogravimetric analysis test conditions: Temperature raised from 30ฐC
to 110ฐC at 40ฐC min.~l 1n N2 and held until no change in weight;
temperature raised from 110ฐC to 600ฐC at 10ฐC cm~l in N2 and held until
no change in weight; O2/N2 introduced and temperature raised from 600ฐC
to 700ฐC at 10ฐC inin."l and held at 700ฐC until no change in weight.
STABILITY OF MSW LEACHATE
A sample of MSW leachate generated in 1976 was located in storage at
Matrecon (Haxo et al, 1982). The sample had been stored in a closed brown
1-gal glass bottle. A considerable amount of dark sediment had collected at
80
-------
the bottom of the bottle, but the supernatant liquid appeared to be relatively
clear, though somewhat translucent. The bottle was shaken and a portion of
the leachate was filtered and analyzed. The leachate had a strong odor of
butyric acid and possibly of valeric acid. The analysis indicated that the
leachate had a pH of 5.06, an electrical conductivity of 9600 jjmho/cm, and
significant concentrations of the following acids:
- Acetic acid (1300 ppm).
- Propionic acid (840 ppm).
- Butyric acid (1160 ppm).
- Valeric acid (1000 ppm).
The analysis indicated that the leachate was quite similar to the leachate
produced for the immersion tests in the work reported by Haxo et al (1982);
thus, the leachate had been stabilized by closing down the cap on the bottle.
81
-------
REFERENCES & BIBLIOGRAPHY
ASTM. Annual Book of ASTM Standards. Issued annually in several parts.
American Society for Teting and Materials, Philadelphia, PA.
Barton, A. F. M. Solubility Parameters. 1975. Chemical Reviews, Vol. 75,
No. 6. pp. 731-753.
Barton, A. F. M. 1983. Solubility Parameters and Other Cohesion Parameters
Handbook. CRC Press, Inc., Boca Raton, FL.
Bellen, G., R. Corry, and M. L. Thomas. 1987. Development of Chemical
Compatibility Criteria for Assessing Flexible Membrane Liners. EPA
600/2-87/067 (NTIS No. PB 87-227 310). U.S. Environmental Protection
Agency, Cincinnati, OH. 492 pp.
Breland, C. G. 1972. Landfill Stabilization with Leachate Recirculation,
Neutralization, and Sludge Seeding. CE 756A6. School of Civil Engineer-
ing, Georgia Institute of Technology. Atlanta, GA. 80 pp.
Brunner, D. R., and R. A. Carnes. 1974. Characteristics of Percolate of
Solid and Hazardous Wastes Deposits. Presented at AWWA (American Water
Works Association) 4th Annual Conference. Boston, MA. 23 pp.
Burrell, H. 1970. Solubility of Polymers. In: Encyclopedia of Polymer
Science and Technology. John Wiley and Sons, New York. 12:618-626.
Burrell, H. 1975. Solubility Parameter Values. In: Polymer Handbook.
Brandrup and Immergut. J. Wiley and Sons, NY.
Chian, E. S. K., and F. B. DeWalle. 1976. Analytical Methodologies for
Leachate and Gas Analysis. In: Proceedings of a Research Symposium on
Gas and Leachate from Landfills: Formation, Collection, and Treatment.
EPA-600/9-76-004 (NTIS No. PB-251-161). U.S. Environmental Protection
Agency., Cincinnati, OH. pp 44-53.
Chian, E. S. K., and F. B. DeWalle. 1977. Evaluation of Leachate Treatment.
2 volumes. EPA-600/2-77-186 a,b. U.S. Environmental Protection Agency,
Cincinnati, OH.
Clark, T. P. and R. Piskin. 1976. Chemical Quality of and Indicator Param-
eters for Monitoring Landfill Leachate in Illinois. Illinois Environ-
mental Protection Agency, Springfield, IL.
82
-------
Dunlap, W. J., D. C. Shew, J. M. Robertson, and C. R. Toussaint. 1976.
Organic Pollutants Contributed to Groundwater by a Landfill. In:
Proceedings of a Research Symposium on Gas and Leachate from Landfills:
Formation, Collection, and Treatment. EPA-600/9-76-004 (NTIS No.
PB-251-161). U.S. Environmental Protection Agency, Cincinnati, OH. pp
96-110.
EPA. 1973. An Environmental Assessment of Potential Gas and Leachate Prob-
lems at Land Disposal Sites. (Open-file report, restricted distribu-
tion.) U. S. Environmental Protection Agency, Washington, DC.
EPA. 1975. Use of the Water Balance Method for Predicting Leachate Gen-
erated From Solid Waste Disposal Sites. SW-168. U. S. Environmental
Protection Agency, Washington, DC. 40 pp.
EPA. 1977. Procedures Manual for Groundwater Monitoring at Solid Waste
Disposal Facilities. EPA-530/SW-611. U.S. Environmental Protection
Agency, Cincinnati, OH. 269 pp.
EPA. 1985. Criteria for Classification of Solid Waste Disposal Facilities
and Practices. 40 CFR Part 257, Appendix II. U.S. Government Printing
Office, Washington, D.C.
EPA. 1986a. Muncipal Landfill Case Studies (unpublished). These studies
were prepared by PEI, SRW, and 1CF. U.S. Environmental Protection
Agency, Office of Solid Waste, Washington, D.C. Cited in: U.S. EPA.
1986b. Subtitle D Study - Phase 1 Report. EPA/530-SW-86-
054. U.S. Environmental Protection Agency, Office of Solid Waste,
Washington, D.C.
EPA. 1986b. Subtitle D Study - Phase I Report. EPA/530-SW-86-054. U.S.
Environmental Protection Agency, Office of Solid Waste, Washington,
D.C.
Fungaroli, A. A. 1971. "Pollution of Subsurface Water by Sanitary Land-
fills", Report SW-12RG Environmental Protection Agency, Washington,
D.C. Cited in: Chian, E. S. K., and F. B. DeWalle. 1977. Evaluation
of Leachate Treatment. 2 volumes. EPA600/2-77-186 a,b. U.S. Environ-
mental Protection Agency, Cincinnati, OH.
Garland, G. A., and D. C. Mosher. 1975. Leachate Effects from Improper
Land Disposal. Waste Age, Vol. 6, No 3. pp 42-48.
Genetelli, E. J., and J. Cirello, eds. 1976. Gas and Leachate from Land-
fills: Formation, Collection, and Treatment. EPA 600/9-76-004. U.S.
Environmental Protection Agency, Cincinnati, OH. 190 pp.
Griffin, R. A., and N. F. Shimp. 1978. Attenuation of Pollutants in
Municipal Landfill Leachate by Clay Minerals. EPA 600/2-78-157 (NTIS
PB 287-140). U.S. Environmental Protection Agency, Cincinnati, OH.
146 pp.
83
-------
Ham, R. K. 1975. Milled Refuse Landfill Studies at Pompano Beach, FL.
Approx. Range, Three Cells Aged One Year. 21 pp.
Ham, R. K. 1976. Solid Waste Degradation Due to Shredding and Sludge
Addition. In: Proceedings of a Research Symposium on Gas and Leachate
from Landfills: Formation, Collection, and Treatment. EPA-600/9-76-004
(NTIS No. PB-251-161). U.S. Environmental Protection Agency, Cincinnati,
OH. pp 168-176.
Ham, R. K., K. Hekimian, S. Katten, W. J. Lockman, R. J. Lofty, D. E. McFaddin,
and E. J. Daley. 1979. Recovery, Processing, and Utilization of Gas
from Sanitary Landfills. EPA-600/2-79-001. U.S. Environmental Protec-
tion Agency, Cincinnati, OH.. 133 pp.
Haxo, H. E. 1977. Compatibility of Liners with Leachate. In: Proceedings of
the Third Annual Municipal Solid Waste Research Symposium. Management of
Gas and Leachate in Landfills. EPA-600/9-77-026 (NTIS No. PB 272-595).
U.S. Environmental Protection Agency, Cincinnati, OH. pp 149-158.
Haxo, H. E. 1988. Transport of Dissolved Organlcs from Dilute Aqueous
Solutions Through Flexible Membrane Liners. In: Proceedings of the
Fourteenth Annual Solid Waste Research Symposium: Land Disposal, Remedial
Action, Incineration and Treatment of Hazardous Waste, May 9-11, 1988.
EPA/600/9-88/021. U.S. Environmental Protection Agency, Cincinnati, OH.
21 pp 145-166.
Haxo, H. E., R. S. Haxo, and T. F. Kellogg. 1979. Third Interim Report:
Evaluation of Liner Materials Exposed to Leachate. EPA-600/2-79-038
(NTIS No. PB 299-336). U.S. Environmental Protection Agency, Cincinnati,
OH. 57 pp.
Haxo, H. E., T. P. Lahey, and M. L. Rosenberg. 1988. Factors in Assessing
the Compatibility of FMLs and Waste Liquids. EPA/600/2-88/017 (NTIS No.
PB 88-173-372/AS). U.S. Environmental Protection Agency, Cincinnati, OH.
143 pp.
Haxo, H. E., and N. A. Nelson. 1984. Permeability Characteristics of
Flexible Membrane Liners Measured in Pouch Tests. In: Proceedings of the
Tenth Annual Research Symposium: Land Disposal of Hazardous Waste. EPA-
600/9-84-007. U.S. Environmental Protection Agency, Cincinnati, OH. pp.
230-251.
Haxo, H. E., N. Nelson, and J. A. Miedema. 1985. Solubility Parameters
for Predicting Membrane-Waste Liquid Compatibility. In: Proceedings of
the Eleventh Annual Research Symposium: Land Disposal of Hazardous Waste.
EPA/600/9-85/013. U.S. EPA, Cincinnati, OH. pp 198-212.
Haxo, H. E., R. M. White, P. D. Haxo, and M. A. Fong. 1982. Final Report:
Evaluation of Liner Materials Exposed to Municipal Solid Waste Leachate.
NTIS No. PB 83-147-801. U.S. Environmental Protection Agency, Cincinnati,
OH.
84
-------
Hildebrand, J. H., and R. L. Scott. 1950. The Solubility of Nonelectrolytes.
3rd edition. Reinhold Publishing Company, New York. 1964. Reprinted
by Dover Publications, NY. 488 pp.
Hughes, G. M., R. A. Landon, and R. N. Farvolden. 1971. Hydrogeology of
Solid Waste Disposal Sites in Northeastern Illinois. Solid Waste
Management Series, Report SW-12d. U.S. Environmental Protection Agency,
Washington, D.C. Cited in: Chian, E. S. K., and F. B. DeWalle. 1977.
Evaluation of Leachate Treatment. 2 volumes. EPA-600/2-77-186 a,b.
U.S. Environmental Protection Agency, Cincinnati, OH.
James, S. C. 1977. Metals in Municipal Landfill Leachate and Their Health
Effects. American Journal of Public Health, 67. pp 429-432.
Kmet, P., and P. M. McGinley. 1982. Chemical Characteristics of Leachate
from Municipal Solid Waste Landfills in Wisconsin. In: Proceedings of
the 5th Annual Madison Conference of Applied Research and Practice on
Municipal and Industrial Wastes, September 22-24, 1982. Dept. of Eng.
and Applied Science, University of Wisconsin Extension, Madison, WI. pp
225-254.
Leo, A. and C. Hansch. 1970. Linear Free-Energy Relationships Between
Partitioning Solvents Systems. Journal of Organic Chemistry, Vol. 36,
No. 11. pp. 1539-1544..
Leo, A., C. Hansch, and D. Elkins. 1971. Partition Coefficients and Their
Uses. Chemical Reviews, Vol. 71, No. 6. pp. 525-554.
Lu, J. C. S., B. Eichenberger, and R. J. Stearns, (n.d.). Production and
Management of Leachate from Municipal Landfills: Summary and Assessment.
Contract No. 68-03-2861. U.S. Environmental Protection Agency, Cincin-
nati, OH. Cited in: U.S. EPA. 1986b. Subtitle D Study - Phase I
Report. EPA/530-SW-86-054. U.S. Environmental Protection Agency,'
Office of Solid Waste, Washington, D.C.
Matrecon, Inc. 1983. Lining of Waste Impoundment and Disposal Facilities.
SW-870 Revised. U.S. Environmental Protection Agency, Washington, D.C.
448 pp. GPO #055-00000231-2.
Matrecon, Inc. 1988. Lining of Waste Containment and Other Impoundment
Facilities. SW-870, second revised edition. EPA-600/2-88-052.
U.S. Environmental Protection Agency, Washington, D.C. 991 pp.
Merz, R. C. 1974. Final Report on the Investigation of Leaching of a
Sanitary Landfill. Publication No. 10, State Water Pollution Control
Board, Sacramento, CA. Cited in: Chian, E. S. K., and F. B. DeWalle.
1977. Evaluation of Leachate Treatment. 2 volumes. EPA-600/2-77-186
a,b. U.S. Environmental Protection Agency, Cincinnati, OH.
Meyers, T. E., N. Francinques, D. W. Thompson, and P. G. Malone. 1980.
Chemically Stabilized Industrial Wastes in a Sanitary Landfill
85
-------
Environment. In: Proceedings of the Sixth Annual Research Symposium:
Disposal of Hazardous Waste. EPA-600/9-80-010. U.S. Environmental
Protection Agency, Cincinnati, OH. pp 223-241.
Murray, R. M., and D. C. Thompson. 1963. The Neoprenes. E.I. duPont de
Nemours and Company (Inc.), Wilmington, DE.
National Sanitation Foundation (NSF). 1985. Standard Number 54: Flexible
Membrane Liners. Rev. Standard. National Sanitation Foundation, Ann
Arbor, MI.
Phillips, N. P., and R. Murray Wells. 1974. Solid Waste Disposal. Final
Report. EPA-650/2-74-033. U. S. Environmental Protection Agency, Wash-
ington, DC. 268 pp.
Pohland, F. G. 1972. Landfill Stabilization with Leachate Recycle. Interim
Progress Report. Grant EP 00658-01. Solid Waste Research Division.
U.S. Environmental Protection Agency, Cincinnati, OH. Cited in:
Chian, E. S. K., and F. B. DeWalle. 1977. Evaluation of Leachate
Treatment. 2 volumes. EPA-600/2-77-186 a,b. U.S. Environmental Pro-
tection Agency, Cincinnati, OH.
Pohland, F. G. 1975. Sanitary Landfill Stabilization and Leachate Recycle
and Residual Treatment. EPA-600/2-75-043. U.S. Environmental Protec-
tion Agency, Cincinnati, OH. 105 pp.
Pohland, F. G. 1976. Landfill Management with Leachate Recycle and Treat-
ment: An Overview. In: Proceedings of a Research Symposium on Gas and
Leachate from Landfills Formation, Collection, and Treatment. EPA-600/
' 9-76-004 (NTIS No. PB-251-161). U.S. Environmental Protection Agency,
Cincinnati, OH. pp 159-167.
Pohland, F. G., and S. R. Harper, (n.d.). Critical Review and Summary of
Leachate and Gas Production for Landfills. U.S. Environmental Protec-
tion Agency, Cincinnati, OH. Cited in: U.S. EPA. 1986b. Subtitle D
Study - Phase I Report. EPA/530-SW-86-054. U.S. Environmental Protec-
tion Agency, Office of Solid Waste, Washington, D.C.
Pohland, F. G., D. E. Shank, R. E. Benson, and H. H. Timmerman. 1979.
Pilot Scale Investigations of Accelerated Landfill Stabilization with
Leachate Recycle. In: Municipal Solid Waste: Land Disposal. Proc. 5th
Annual Res. Sympos. EPA-600/9-79-023a. U.S. Environmental Protection
Agency, Cincinnati, OH. pp 283-295.
Pohland, F. G., W. H. Cross, and J. P. Gould. 1987. The Behavior and As-
similation of Organic and Inorganic Priority Pollutants Codisposed
with Municipal Refuse - A Progress Report. In: Proceedings of the
Thirteenth Annual Research Symposium: Land Disposal of Hazardous Waste.
EPA-600/9-87-015. U.S. Environmental Protection Agency, Cincinnati,
OH. pp 26-37.
Reinhard, M., N. L. Goodman, and J. F. Barker. 1984. Occurrence and Dis-
tribution of Organic Chemicals in Two Landfill Leachate Plumes.
Environmental Science and Technology 18(12):953-961.
86
-------
Relnhardt, J. J., and R. K. Ham. 1973. Final Report on a Demonstration
Project at Madison, Wisconsin, to Investigate Hilling of Solid Wastes
Between 1966 and 1972, Vol. 1. U.S. Environmental Protection Agency,
Office of Solid Waste Management Program, Washington, D.C. Cited in:
Chian, E. S. K., and F. B. DeWalle. 1977. Evaluation of Leachate
Treatment. 2 volumes. EPA-600/2-77-186 a,b. U.S. Environmental Pro-
tection Agency, Cincinnati, OH.
Riddick, J., and W. Bunger. 1970. Techniques of Chemistry Volume II -
Organic Solvents, Physical Properties and Methods of Purification.
Wiley-Interscience, New York.
Sabel, G. V., and T. P. Clark. 1984. Volatile Organic Compounds as In-
dicators of Municipal Solid Waste Leachate Contamination. Waste
Management and Research (2):119-130.
Sawhney, B. L., and R. P. Kozloski. 1984. Organic Pollutants in Leachates
from Landfill Sites. J. Environ. Qua!. (13):349-352-
Shultz, D., and D. Black. 1981. Land Disposal: Municipal Solid Waste Pro-
ceedings of the Seventh Annual Research Symposium. EPA 600/9-81-002a,
U.S. Environmental Protection Agency, Cincinnati, OH. Cited in: U.S.
EPA. 1986b. Subtitle D Study - Phase I Report. EPA/530-SW-86-054.
U.S. Environmental Protection Agency, Office of Solid Waste, Washington,
D.C.
Solid and Hazardous Waste Research Laboratory (SHWRL). 1973. "Interim
Report 1, Test Cell 1, Boone County Field Site", National Environmental
Research Center, Cincinnati, OH. Cited in: Chian, E. S. K., and F. B.
DeWalle. 1977. Evaluation of Leachate Treatment. 2 volumes. EPA-600/
2-77-186 a,b. U.S. Environmental Protection Agency, Cincinnati, OH.
Steiner, R. L., A. A. Fungaroli, R. J. Schoenberger, and P. W. Purdon. 1971.
Criteria for Sanitary Landfill Development. Public Works. 102(3):77-79.
Uloth, V. C., and D. S. Mavinic. 1977. Aerobic Biotreatment of a High-
Strength Leachate, Journal of the Environmental Engineering Division,
American Society of Civil Engineers, Vol. 103, No. EE4. pp 647-661.
U.S. General Services Adminstration. 1980. Method 2065: Puncture Resistance
and Elongation Test (1/8-Inch Probe Method), and Method 2031: Tetra-
hedral-Tip Probe Method. In: Federal Test Method Standard 101C. U.S.
Services Administration, Washington, D.C.
Van Krevelen, D. W., and P. J. Hoftyzer. 1976. CED Properties of Polymers
Their Estimation and Correlation with Chemical Structure. Elsevier
Publishing Company, Amsterdam, p 110.
Wigh, R. J. 1979. Boone County Field Site. Interim Report, Test Cells 2A,
2B, 2C, and 2D. EPA-600/2-79-058. U. S. Environmental Protection
Agency, Cincinnati, OH. 202 pp. (NTIS PB-299-689).
87
-------
APPENDIX A. BASELINE PROPERTIES OF UNREINFORCED FMLS
Di recti on
of test
FMLa
Property
PVC
CPE
HDPE
CSPE-LW
Thickness:
Nominal, mil
Measured, mil
30
30.7
30
29.6
30
29.5
30
30.6
Specific gravity
1.26
1.358 . 0
.9507
Volatile loss, %
0.48
0.45
-0.18
ฆ
Tensile properties
Tensile at yield, ppi
Machine
Transverse
m
m ซ ซ
84
93
ซ
Elongation at yield, %
Machine
Transverse
ป
ฆ
10
8
ซ ซ
ซ ซ ซ
Breaking factor, ppi
Machine
Transverse
88
85
54
48
153
163
49.0
40.0
Elongation at break, %
Machine
Transverse
450
465
435
610
645
665
210
305
Stress at 100%
elongation, pp1
Machine
Transverse
51
47
38
18
ซ
*
Tear resistance, lb
Machine
Transverse
10.6
10.5
7.5
6.1
26.0
27.0
12.7
10.2
aPVC = polyvinyl chloride; CPE = chlorinated polyethylene; HDPE = high-
density polyethylene; CSPE-LW = low water absorption (industrial grade)
chlorosulfonated polyethylene.
Source: Bellen et al, 1987 (extracted from Tables 6, 7, 10, and 11).
88
-------
APPENDIX B. TEST METHODS9 USED FOR DETERMINING
BASELINE PROPERTIES OF UNREINFORCED FMLS
FML*>
Property
PVC
CPE
HDPE
CSPE-LW
Thickness
ASTM D1593
ASTM D1593
ASTM D1593
ASTM D1593
Specific gravity
ASTM D792,
Method A
ASTM D792,
Method A
ASTM D792,
Method A
ASTM D792,
Method A
Volatile loss
ASTM D1203,
Method A
ASTM D1203,
Method A
ASTM D1203,
Method A
ASTM D1203,
Method A
Tensile properties
ASTM D882,
Method A or
ASTM D882,
B Method A or B
ASTM D638
ASTM D882,
Method A or B
Tear resistance
ASTM D1004,
Die C
ASTM D1004,
Die C
ASTM D1004,
Die C
ASTM D1004,
Die C
aASTM = American Society for Testing and Materials.
&PVC = polyvinyl chloride; CPE = chlorinated polyethylene; HDPE = high-
density polyethylene; CSPE-LW = low water absorption (industrial grade)
chlorosulfonated polyethylene.
Source: NSF Standard 54 (1985).
89
-------
APPENDIX C. EFFECT OF LONG-TERM IMMERSION OF PVC AND CPE FWLS IN *)UEOUS SOLUTIONS OF SELECTED ORGANICS AT 23ฐ AND AT 50ฐCa
23ฐ C 50ฐ C
Retention
. *
Retention
, *
FMLb
Concentra-
Number
Percent
Tensl1e
Elongation
Number
Percent
Tensile
Elongation
Solvent0
tion, X
of days
swell
S-100
strength
at break
of days
swel 1
S-100
strength
at break
PVC
Phenol
1
723
5.5
83
102
114
721
7.5
80
92
103
4
8d
722
4.5
118
98
107
720
1.0
118
103
112
722
16.1
149
100
38
720
6.5
143
88
51
Furfural
1
720
4.9
71
84
106
718
6.4
84
90
97
4
8d
720
17.7
36
50
93
718
18.9
47
56
76
715
91.8
14
25
87
713
86.0
25
34
79
MEK
3
724
4.5
65
88
107
722
10.4
60
85
114
13
723
21.0
22
47
124
721
35.6
25
67
123
26d
724
42.0
6
20
108
722
10.3
...
131
6
DCE
0.1
730
1.0
95
98
99
728
3.0
101
99
108
0.5
713
-missing
from table-
727
4.6
88
91
107
0.8d
728
13.7
53
78
120
726
14.3
69
74
83
Distilled
100
737
0.7
100
106
107
735
'2.5
96
95
112
water
NaCI
10
737
0.9
97
101
102
735
0.7
106
104
106
CPE
Phenol
1
720
45.9
60
82
107
721
142.2
83
84
69
4
719
59.0
33
55
117
720
179.5
42
52
115
8
-------
APPENDIX D. EFFECT OF LONG-TERM IMMERSION OF HOPE AND CSPE-LK FMLS IN AQUEOUS SOLUTIONS OF SELECTED ORGANICS AT 23ฐ AND AT 50ฐCซ
23ฐ C 50" C
Retention
. 1
Retention
. %
FMLb Solvent^
Concentra-
Number
Percent
Tensile
Elongation
Number
Percent
Tensile
Elongation
tion, f
of days
swell
S-100
strength
at break
of days
swell
S-100
strength
at break
HOPE Phenol
1
756
0.7
ฆ
100
101
758
1.0
103
116
4
755
1.2
107
105
757
2.3
112
128
8d
755
1.2
...
109
111
757
1.0
...
109
111
Furfural
1
754
0.8
...
109
102
756
0.5
118
118
4
754
1.6
109
105
756
1.3
108
127
8d
748
1.5
...
105
105
750
1.5
...
111
126
MEK
3
757
0.3
101
108
759
0.2
...
117
121
13
756
0.9
100
110
758
0.6
104
128
26d
757
1.8
...
101
118
759
0.8
...
105
113
DCE
0.1
763
0.4
...
103
99
765
0.1
ซ
105
111
0.5
762
0.6
109
112
764
0.1
112
108
0.8d
761
1.4
...
105
112
763
1.0
...
107
103
Distilled
100
770
0.5
...
108
101
772
0.3
117
113
water
NaCl
10
738
0.2
...
100
100
743
0.5
...
105
92
CSPE-LH Phenol
1
241
2.4
75
96
125
242
23.5
54
116
94
4
241
7.3
60
81
142
242
39.5
40
85
95
8d
241
12.6
53
82
149
242
44.0
33
67
107
Furfural
1
241
4.5
74
98
125
242
19.7
59
109
93
4
241
8.3
70
93
121
242
22.6
58
101
90
8
241
15.8
56
83
125
242
37.9
55
67
54
MEK
3
241
5.1
71
95
131
242
20.1
55
101
87
13
240
11.6
61
93
140
242
27.4
43
71
86
26d
241
19.5
44
89
136
242
37.5
33
30
69
DCE
0.1
241
3.8
74
95
115
242
20.1
57
109
92
0.5
241
7.5
68
89
122
242
21.3
56
113
101
0.8d
241
9.4
65
87
130
242
21.6
54
98
95
Distilled
water
100
241
3.7
80
87
112
242
20.3
60
no
87
NaCl
10
...
0.1
92
110
95
0.8
85
97
120
'Extracted from Bellen et al, 1987.
aHDPE - high-density polyethylene; CSPE-LH - low water absorption (industrial grade) chlorosulfonated polyethylene.
bMEK ซ methyl ethyl ketone; DCE ซ 1,2-Dlchloroethane.
Saturated solution.
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before complefi'
1. REPORT NO. 2.
EPA/600/2-91/040
a. i
4. TITLE AND SUBTITLE
Compatibility of Flexible Membrane Liners
and Municipal Solid Waste Leachates
5. REPORT DATE
Auqust 1991
6. PERFORMING ORGANIZATION CODE
7. AUTHOHIS]
Henry E. Haxo, Jr.
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Matrecon, Inc.
Alameda, CA 94501
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-03-3413 WP#1536
12. SPONSORING AGENCY NAME AND ADDRESS
Risk Reduction Engineering Laboratory - Cincinnati, OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
13. TYPE OF REPORT AND PERIOD COVERED
Complete
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
Robert E. Landreth (513) 569-7871 FTS: 684-7871
16. ABSTRACT
In a study designed to determine the current composition of municipal solid
waste (MSW) leachate and its chemical resistance with flexible membrane liners
(FMLs), the literature was surveyed and limited experiments on absorption of
organics by FMLs were done. The object of this survey and study was to assess
how well EPA Method 9090 can evaluate the resistance of FMLs with MSW leachate.
It should be noted that EPA Method 9090 was originally developed for evaluating
the chemical resistance of FMLs with hazardous waste leachate. At present, it is
questionable whether Method 9090 yields realistic results for judging this
resistance. The Method may yield misleading results because of the instability
of the MSW leachate and the low concentrations of leachate organics presently
reported..'
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Ficid/Group
>
ia. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS f Tin's Report)
Unclassified
21. NO. OF PAGES
107
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2230-1 (Ra*. 4-77) previous edition is obsolete
------- |