EPS-600/3-75-011 L „ .
October 1975 Ecological Research Series
COMPILATION OF METHODOLOGY USED FOR
MEASURING POLLUTION PARAMETERS OF
SANITARY LANDFILL LEACHATE
Municipal Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45288
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RLSLAkCh REkORIiNC '..[P.Hi-
Research reports of the Office of Research and Development, I' S. Environ-
mental Protection Agency, nave been grouped into five :,ene:. These five
broad cctego'-ies were established to facilitate furtner aeveiopment arid
dppl i cat i on ot environmental technology n tniin^-ini. "•* t •";-:' t ">:"":si
group was consciously planned to foster technology transfer and ? maximum
interface in related fields. The five series are:
I. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4, Environmental Monitoring
5. Socioeconornic Environmental Studies
This report has been assigned to the ECOLOGICAL RESEARCH series. This
series describes research on the effects of pollution on humans, plant and
animal species, and materials. Problems are assessed for their long- and
short-term influences. Investigations include formation, transport, and
pathway studies to determine the fate of pollutants arid their effects.
This work provides the technical basis for setting standards to minimize
undesirable changes in living organisms in the aquatic, terrestrial and
atmospheric environments.
This document is available to the public through the National Technical
Information Service, Springfield, Virginia 22161.
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EPA-600/3-75-011
October 1975
COMPILATION OF METHODOLOGY FOR
MEASURING POLLUTION PARAMETERS OF LANDFILL LEACHATE
Edward S. K. Chian
Foppe B. DeWalle
Environmental Engineering
Department of Civil Engineering
University of Illinois
Urbana, Illinois 61801
Program Element No. 1DB064
Contract No. CI 68-03-2052
Project Officer
Richard A. Carnes
Solid and Hazardous Waste Research Division
Municipal Environmental Research Laboratory
Cincinnati, Ohio 45268
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF AIR, LAND, AND WATER USE
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Municipal Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publication.
Approval does not signify that the contents necessarily reflect the views and
policies of the U.S. Environmental Protection Agency, nor does mention of trade
names or commercial products constitute endorsement or recommendation for use.
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FOREWORD
Man and his environment must be protected from the adverse effects
of pesticides, radiation, noise and other forms of pollution, and the
unwise management of solid waste. Efforts to protect the environment
require a focus that recognizes the interplay between the components of
our physical environment—air, water, and land. The Municipal Environ-
mental Research Laboratory contributes to this multidisciplinary focus
through programs engaged in
• studies on the effects of environmental contaminants on the
biosphere, and
• a search for ways to prevent contamination and to recycle
valuable resources.
This study made an extensive compilation of the different analytical
methods used to determine physical, chemical, and biological parameters
in solid waste leachate.
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ABSTRACT
The present study made an extensive compilation of the different
analytical methods used to determine physical, chemical and biological
parameters in solid waste leachate. The compilation was made from
information available in the literature and through personal communications
with researchers, consulting firms and regulatory agencies.
Since different analytical methods can be used to determine a specific
parameter, a preliminary laboratory evaluation was made of those methods
least subject to interferences. All analyses were conducted with a relatively
concentrated leachate sample obtained from a lysimeter filled with milled
solid waste. The results indicate that strong interferences are sometimes
encountered when using colorimetric tests due principally to the color
and suspended solids present in leachate. In such instances alternative
methods were evaluated or recommendations were made to reduce the inter-
fering effects. Automated chemical analysis using colorimetric methods
can sometimes experience significant interferences.
Further research is necessary to evaluate additional methods using
leachate samples of different strengths and collected from landfills of
different ages. The precision and sensitivity of each method will also have
to be determined. The interfering parameter should be quantified to allow
predictions of its magnitude with leachate samples of different strengths.
This report was submitted in fulfillment of Project Number
Contract Number 68-03-2052, by the University of Illinois, Department of
Civil Engineering, Environmental Engineering Section, under the sponsor-
ship of the U. S. Environmental Protection Agency.
IV
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TABLE OF CONTENTS
Abstract iv
List of Figures vii
List of Tables ix
Acknowledgements x
Sections
1 Conclusions 1
2 Recommendations 2
3 Introduction 3
4 Sampling Procedures 4
4.1 Sample Collection 4
4.2 Sample Preservation, Handling and Storage ....... 6
4.3 Selection of Parameters to be Measured 10
4.4 Complications During Field Sampling 10
5 Methodology of Method Evaluation . 12
5.1 Standard Addition Method 12
5.2 Dilution Method 14
6 Physical Parameters 16
6.1 pH Determination 16
6.2 ORP Determination 17
6.3 Conductivity 18
6.4 Residue Determination 19
7 Organic Chemical Parameters 26
7.1 The COD Determination 26
7.2 The TOC Determination 31
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Section Page
7.3 Volatile Acids Determination 36
7.4 The Tannin and Lignin Determination 41
7.5 The Organic Nitrogen Determination 43
8 Inorganic Chemical Parameters 49
8.1 The Chloride Determination 49
8.2 The Sulfate Determination 58
8.3 The Phosphate Determination 62
8.4 Alkalinity and Acidity 73
8.5 The Nitrate Determination 79
8.6 The Nitrite Determination 85
8.7 The Ammonia Determination 89
8.8 The Sodium and Potassium Determination 97
8.9 The Calcium and Magnesium Determination 100
8.10 Hardness Determination 104
8.11 Determination of Heavy Metals 105
9 Biological Parameters . 108
9.1 The BOD Determination 108
9.2 The Coliform Determination 115
10 Miscellaneous Determination 122
11 References 123
12 Appendix A 126
13 Appendix B I50
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LIST OF FIGURES
Figure Page
1 Change of COD, Turbidity, Color and pH with Time
of Storage at 4° C 8
2 Change of SS, ORP and Conductivity with Time of
Storage at 4° C 9
3 The Total-P Determination with the Ascorbic Acid
Method in the 1:50 and 1:100 Diluted Leachate
Sample Using the Standard Addition Method 13
4 The Total-P Determination with the Ascorbic Acid
Method in a Leachate Sample Using the Progressive
Dilution Method 15
5 Effect of Heating Temperature on the Volatile
Solids Determination when Sample was Heated for
One Hour in a Furnace 23
6 Effect of Amount of Sulfuric Acid and Normality
of Dichromate on the Results of the COD Test 28
7 Effect of Reflux Time on the Results of the COD
Test 28
8 Calibration Curve of TOC Analyzer for Low
Concentration Ranges 33
9 The TOC Analysis of a Membrane Fractionated Leachate
Sample 34
10 The Organic Acid Determination with the Column
Partition Chroma tog raphic Method 38
11 The Organic Acid Determination with the Hydroxyl-
amine Test 39
12 The Organic Nitrogen Determination with the
Kjeldahl Method 44
13 Effect of Digestion Time on the Concentration of
Organic-N Finally Measured in the 1:10 Dilution.. 46
14 Calibration Curve of the Chloride Electrode 51
15 Chloride Determination Using Direct Potentiometric
Readings in the Diluted Leachate Sample 52
16 Titration Curve of 1000 mg/1 Cl~ Solution and a
1:2 and 1:4 Diluted Leachate Sample 53
vii
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Figure Page
17 Determination of Normality of AgN03 Solution 55
18 The Chloride Determination by the Standard Addition
Method Using Titration to Inflection Point in the
Di 1 uted Leachate Samp! e 56
19 The Sulfate Determination with the Gravimetric
Method in the 1:2 and 1:4 Diluted Leachate Samples.. 60
20 The Ortho Phosphate Determination with the Ascorbic
Acid Method in 1:4 and 1:6 Diluted Leachate Samples. 65
21 Effect of Amount of Digestion Reagent on the Results
of the Total P Determination 66
22 Effect of Digestion Time on the Result of the Total
P Determinati on 68
23 The Total-P Determination with the Ascorbic Acid
Method in the 1:50 and 1:100 Diluted Leachate Sample
Using the Standard Addition Method 69
24 The Total-P Determination with the Ascorbic Acid
Method in a Leachate Sample Using the Progressive
Dilution Method 70
25 Titration Curves of Leachate Samples of Different
Pollutional Strength 76
26 Effect of Free Volatile Fatty Acid Concentration on
the pH of the Inflection Point of the Titration Curve. 77
27 The Nitrate Determination with the Nitrate Electrode
Using Standard Additions 82
28 Calibration Curve of the Nitrate Electrode 83
29 The Nitrate Determination with the Brucine Sulfanilic
Acid Method Using Standard Additions 84
30 The Nitrite Determination with the Naphthylamine Method
Using Standard Additions 87
31 Calibration Curve for the Ammonia Electrode 91
32 The Ammonia Determination with the Potentiometric
Method Using Standard Additions 92
33 The Ammonia Determination with the Distillation Method
Using Standard Additions 94
34 Effect of Final pH of Distillate on Recovery of Ammonia
during the Kjeldahl Distillation 95
viii
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Figure Page
35 The DO Uptake as Affected by the Dilution Used, as
Measured in a Biologically Stabilized Leachate HO
36 The DO Uptake as Affected by the Dilution Used, as
Measured in a Leachate Sample from A fill Recently
Generating Leachate Ill
37 Relation Between Measurement of Total and Fecal
Coliforms by Most Probable Number Technique and by
Membrane Filtration Technique (Smith, 1972) 117
38 Recovery of Bacteria Added in Identical Amounts to
a Buffer Solution and a Leachate Sample Respectively,
Both Maintained at 25° C Immediately after Its Addition
(Engelbrecht and Amirhor, 1975) 119
LIST OF TABLES
Table Pagi
1 Effect of Drying Temperature on the Total Solids
(TS) Determination 21
IX
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ACKNOWLEDGEMENTS
The support of the U.S. EPA Solid and Hazardous Waste Research
Division of the Municipal Environmental Research Laboratory (formerly
the Solid and Hazardous Waste Research Laboratory of the National
Environmental Research Center) is acknowledged with sincere thanks.
Major contributions were made by Richard Carnes and Dirk Brunner
during the course of the study, while Dr. Daniel Bender, Donald
Wilson and Nancy Ulmer, formerly employed with the SHWRL, also helped
to a great extent. The chemical analyses were conducted at the
University of Illinois and performed by Richard Davison, laboratory
chemist, Research Assistants, Paul Jennings and Gulerman Surucu, and
the Laboratory Assistants, Bob Clarke, Priscilla Strange, Clyde Stroup,
and Martha Sweeney. The laboratories listed in Appendix A contributed
greatly during the methods compilation phase of the study, and sincere
thanks is extended to them.
The analytical methods evaluated in the present study for their
applicability in leachate analysis are listed in Standard Methods,
published by the American Public Health Association (APHA) Washington,
D.C., and Methods for Chemical Analysis of Water and Wastes published
by U.S. EPA, Washington, D.C. Permission given by A. Seeber of the
APHA to reproduce sections of Standard Methods in the present document
is greatfully acknowledged. Consultation of both Manuals, however,
remains necessary for the successful execution of the chemical analysis.
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SECTION 1
CONCLUSIONS
It was concluded that samples collected from a recently installed
solid waste fill undergo extensive changes of several parameters
immediately after collection, unless strict anaerobic sampling and
storage conditions are maintained. Preliminary laboratory evaluation
of physical, chemical and biological parameters showed that chemical analysis
using colorimetric methods is strongly interfered by color, suspended solids
and high salt content present in leachate. Interfering effects can be
reduced by using a standard addition method in which increasing quantities
of the specific parameter are added to the sample after which its recovery
is determined. The obtained percentage recovery is then used to readjust
the measured value. A less accurate method is to dilute the leachate
sample with increasing amounts of dilution water to determine whether the
interfering effect can be sufficiently reduced by progressive dilution.
One of the above approaches should be used by the analyst prior to the analysis
of a series of leachate samples for those parameters most subject to inter-
ferences.
An extensive compilation of the different analytical methods used by
researchers,consul ting firms and regulatory agencies in the U.S.A., showed
that numerous methods are used to determine a specific parameter. Based
on research conducted at the University of Illinois recommendations were
made to use those methods least subject to interference.
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SECTION 2
RECOMMENDATIONS FOR RESEARCH
The present study conducted a preliminary evaluation of those methods
to measure a certain parameter which were least subject to interference.
Since only the accuracy of each selected method was evaluated, further
research will have to establish the precision and sensitivity. Since all
analyses were conducted with a relatively concentrated leachate sample,
additional leachate samples of different strength and collected from
landfills of different ages, will have to be evaluated.
Methods that are less complicated and time-consuming, but subject to
larger interferences than the recommended methods should be evaluated as
they are likely to be used under field conditions. For example, although
the Kjeldahl distillation is recommended for accurate ammonia determina-
tions, the more rapid Nessler method will often be used under field
conditions, and should, therefore, be evaluated.
All automated methods as recommended by EPA (1974) for water and
wastewater and Technicon (1973) for industrial waste should be evaluated
for possible interferences since most tests are based on colorimetric
analyses which are generally subject to strong interference by the color
and suspended solids present in leachate. Such evaluation is necessary
since increasing amounts of leachate samples will be analyzed by auto-
mated methods at a future date.
It is recommended that further research should be conducted, including
a literature search, to establish correlations between specific constit-
uents and general parameters such as conductivity, absorbance at 400 nm
and pH. These three parameters are easy to determine and are, therefore,
valuable for monitoring and enforcement purposes as they can be used to
screen large numbers of samples. Especially when these parameters exceed
a certain value, to be determined by further research, will it be warranted
to conduct further and more costly chemical analysis.
It is finally recommended that further research establish the exact
nature of the interfering substance. When the interference is caused by a
common parameter that is generally included in the measurements such as
total solids, chlorides or sulfates, the knowledge of the concentration of
the interfering parameter can be used to adjust the calculated concentra-
tion of the interfered measurement. This eliminates the need to run time-
consuming starJard addition curves for the interfered measurement.
Research should also indicate ways to reduce these interferences when
their exact nature has been established. When it is caused by the color
and suspended solids present in leachate, massive lime dosages may be
effective in eliminating these specific interferences. The effectiveness
of coagulation will have to be evaluated. Other steps such as ion exchange
or activated carbon treatment to remove certain interferences, also will
have to be studied.
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SECTION 3
INTRODUCTION
The oldest method of solid waste disposal, that of landfilling, is
still the most widely used. This method can have an adverse effect on
the environment unless sound engineering principles are used during
design, operation and long term maintenance of the solid waste fill. When
infiltration of rainwater is not restricted the water will dissolve
organic and inorganic substances from the solid waste. The leachate thus
generated may move out of the fill into the surrounding soil and subsequently
pollute groundwaters or nearby aquifers. In several instances regulatory
agencies (State of Illinois, 1973) have therefore required monitoring of
the environment to determine the impact of landfill ing. To minimize such
impact clay layers, asphalt, plastic or rubber liners, are placed at the
bottom of the fill prior to the disposal of the solid waste (Anon, 1972)
to prevent leachate migration. Leachate treatment facilities are then a
necessity and have, therefore, been installed at several landfills (Cressman,
1973; Schoenberger, et aJL , 1971).
The environmental impact of leachate,dependent on leachate strength,
attenuation in surrounding soils, biodegradation and efficiency of leachate
treatment, requires the accurate, consistent determination of several water
contaminants. It is the purpose of the present study to review the analy-
tical methods to determine contaminants as reported in the literature. The
methods compiled and evaluated in this study were generally reported in
the literature; additional information was obtained by contacting the
principal investigators. Interferences in the chemical analysis due to
the complex nature of the leachate as enumerated in the reported studies
are listed in this report.
The compilation showed that different methods subject to different
interferences are used to determine a certain parameter. For each parameter
only that method was evaluated in this laboratory, which was found to have
the smallest interference. The laboratory evaluation tested the method for
its susceptibility to certain interferences commonly found in leachate. In
addition the accuracy of the method was tested. All laboratory analyses were
performed using a high strength leachate sample obtained from a recently
installed lysimeter filled with milled refuse. Recommendations made in
this report, therefore, only apply to leachate of similar strength. No
evaluation was made of precision and sensitivity of each method since this
was beyond the scope of the work. Realizing the above restrictions,
recommendations were made in the present study for the selection of those
methods least subject to interference. Further recommendations were made
concerning modifications of the selected methods.
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SECTION 4
SAMPLING PROCEDURES
4.1 SAMPLE COLLECTION
Principle
Leachate can be collected from subsurface soil strata by using wells
or piezometers placed in drilled holes. A piezometer is a screen or
permeable plastic tip fastened to the end of a pipe or tube, installed in
a boring. The annul us above it is sealed so that the water level measure-
ments or water samples obtained from this installation apply only to a
restricted area in the bottom part of the boring below the seal in the
annul us. A well point is similar to a piezometer except that there is
generally no seal in the annul us and therefore measurements or water
samples obtained from a well point may reflect conditions over a large
vertical interval (Hughes, et al_., 1971). In some instances the annulus
of a well point is also sealed, but it still reflects conditions over a
larger vertical interval as obtained with piezometers. Pore water samples
above the groundwater table are collected with suction lysimeters (Apgar
and Langmuir, 1971). As leachate permeates through the soil in relatively
thin strata of higher permeability, the collection device should be placed
at such a depth that it includes such permeable strata.
Leachate collected above ground may appear in springs or at the toe
of a solid waste disposal site. Such samples may contain eroded soil and
will have reacted with the soil to significantly affect its quality. On
such samples a suspended solids determination should be performed. The
soil should be removed by sedimentation and not by filtration as the latter
method may remove significant quantities of heavy metals and phosphates.
Filtration (0.45 y) should only be used when the suspended solids interfere
significantly with the chemical analysis.
Leachate may also reach the surface and enter the surface waters
directly through groundwater discharge zones. In such instances an estimate
will have to be made of the approximate extent of the dilution.
Interference
The characteristics of leachate can be effected by the methods and
materials used. Apgar and Langmuir (1971) for example obtained their
sample from suction lysimeters with an effective pore diameter of 1 y.
Hughes et a]_. (1971) used predominantly No. 10 brass well screens with an
opening larger than 5 mm. Fungaroli (1971) did not use drain pipes but
collected leachate through sand and glass beads of increasing size. Most
studies, however, do not mention the type of sampling device through which
the leachate was collected. One of the studies, for example, only mentioned the
soil material used to back fill the leachate collection trenches in which
perforated pipe was embedded, but did not specify the openings in the
leachate collection pipes.
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The effective pore diameter of the material through which the leach-
ate is collected may have an appreciable effect on the concentration of
several parameters such as suspended solids, phosphates and heavy metals
since precipitates or coatings may be formed near the collection device
which may filter out these materials.
The construction of the collection devices should be such that it
maintains anaerobic conditions and minimizes entry of air, as this will
enhance aerobic degradation of the sample. The material
used for the construction of the collection device may also have some
effect on the leachate characteristics and should therefore be specified.
The aqueous sample present in the subsurface collection device can
be obtained by using a bailer, by applying suction or by pressurizing one
of the sampling tubes present in the collection device. The sampling
device can have an effect on the outcome of the chemical analysis. A
bailer, for example, may primarily remove the upper portions of the liquid
in the collection device, while suction or pressure devices may preferentially
remove the lower portions containing more suspended solids and heavy metals.
Complete mixing of the content of the collection device before sampling is
therefore necessary. The sample collection above ground is generally less
complicated and can proceed by lowering the sample bottle in the leachate
stream. When the stream is very shallow, a small trench may have to be
excavated to collect sufficient amount of leachate. After construction of
the trench it is necessary to allow settling of the soil particles, which
otherwise erroneously increase the suspended solids analysis.
The sample volume to be collected will depend on the permeability of
the strata, the permeability of the wall of the collection device, the
allowed detection time in the collection device and the number of analysis
to be performed.
Recommendation
It is therefore recommended that site and leachate sampling conditions
be specified when results of chemical analysis are presented. Such speci-
fications should include a description of the soil, the construction, depth
and characteristics of the sampling device, the effectiveness of the device
to maintain anaerobic conditions and the approximate detention time of the
leachate in the collection device. The content of the collection device
will have to be mixed before withdrawal of the aqueous sample. When the
leachate is collected from the surface, the soil conditions should be spec-
ified as well as the time that the leachate is exposed to aerobic conditions.
Other characteristics that will help to explain the results of the chemical
analysis should also be reported.
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4.2 SAMPLE PRESERVATION, HANDLING AND STORAGE
Principle
Leachate collected from a recently installed solid waste fill will have
a translucent light brown color, but it will turn dark green or black and
become turbid immediately after collection due to aerobic exposure and the
subsequent oxidation of heavy metals and organics. The odor is very dis-
agreeable and nauseating and is generally due to the presence of free vola-
tile fatty acids such as butyric and valeric acid. Leachate samples collected
from an older solid waste fill are generally light brown to light yellow and
do not change color directly after sampling, since they are more stabilized
and have lower metal concentrations. The odor is not offensive since free
volatile fatty acids are generally absent due to active methane fermenta-
tion. Collection of leachate samples below the surface at older sites,
will result in the liberation of C02 gas bubbles when the sample is exposed
to atmospheric pressures, which will cause a reduction in bicarbonate
alkalinity.
Cook (1966) showed that storage of leachate with a COD of 1200 mg/£
and a pH of approximately 7.5 in a quart jar capped with aluminum foil and
maintained at room temperature caused a 55 percent COD reduction after
three weeks with most of the decrease occuring after one week. A leachate
sample in extensive contact with the atmosphere prior to sampling showed
a 61 percent reduction due to the presence of more adapted aerobic microbial
populations.
None of the other studies reported in the literature quantitatively
measured the changes of specific contaminants with time of storage,
although some studies reported visual changes in the sample. None of the
studies evaluated the effectiveness of different preservation techniques.
Evaluation of sample changes
Several characteristics listed in Standard Methods which are used to
characterize the nature of leachate, are subject to changes immediately
after sampling. To illustrate the necessity of establishing strict sampling
procedures, these parameters have been studied simultaneously as a function
of time immediately after the sampling of leachate from a lysimeter located
at the University of Illinois. The leachate was collected in a 4£ bottle
filled to the top. Small samples were withdrawn from the bottle at regular
intervals for analysis while the capped sample bottle was stored in the
coldroom at 4° C. The parameters that were monitored during this period
included Chemical Oxygen Demand (COD), Turbidity, Color (absorbance at 400
nm of the 1:10 diluted sample), pH, Suspended Solids (SS), Oxidation
Reduction Potential (ORP) and Conductivity (Figure 1 and 2). The most
pronounced changes took place with the SS, ORP, turbidity and color of the
sample, which corresponded to a visual change of the sample color from
light yellow to dark brown. This is caused by the oxidation of the ferrous
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iron to ferric hydroxide. The formation of ferric hydroxides contributes
to the increase of color, turbidity and SS. The increasing ferric hydroxide
content of the SS was reflected by the percent of fixed suspended solids
which increased from an initial 18.2 percent to 50.3 percent at the end of
the monitoring period. Since some of the "apparent" volatile suspended
solids is contributed by the loss of bound water in ferric hydroxide at
550° C, the percent of inorganics in suspended solids at the end of the
monitoring period may be higher than 50.3 percent. The oxidation of the
organic matter and the iron caused a decrease of the COD by 6.8 percent
and the formation of a precipitate. It also causes the conductivity to
decrease. Figures 1 and 2 depict results of this study within a 12 day
period. Eighty minutes after the first sample was withdrawn from the lysi-
meter, a second sample was collected. Comparison of the data showed that
the sample has a higher initial COD of 31,600 versus 31,000 mg/£, while
the turbidity, pH and color were slightly higher in the first sample. The
ORP was more negative with the first sample than in the second. The initial
suspended solids (SS) were approximately equal in both samples. The final
COD in the 2 samples after 13 days of storage time was approximately equal,
i.e. 29,000 mg/£ for the first sample and 29,071 mg/£ for the second sample.
The final suspended solids were higher for the second sample. Since a
fraction of the COD decrease is contributed by the oxidation of the iron,
it is expected that an initial higher COD would result in a higher SS and
turbidity after prolonged storage. This was indeed observed. In conclu-
sion, the same results of rapid increase of turbidity, SS and color and
stabilization of ORP were confirmed with the second sample.
Recommendations
Based on these observations it is recommended that several parameters
be determined directly after collection of the sample or if this cannot be
accomplished the leachate should be collected under anaerobic conditions
in a tightly stoppered bottle, refrigerated and analysed for the parameters
most susceptible to change directly after arrival in the laboratory. The
sample should be stored in a glass bottle for organic analysis as this
keeps the sample more anaerobic. For heavy metal analysis the sample is
preferably stored in a polyethylene bottle as it prevents adsorption of
heavy metals onto the wall of the container. The sequence of parameter
analyses should be ORP, color, turbidity, suspended solids, pH and
conductivity. Other parameters such as COD and organic N may also change
directly after sampling but these changes may be reduced when the sample
is acidified. Acidification and storage at 4° C will stop the methane
fermentation, the process which is responsible for free volatile fatty
acid removal, while it also slows the bacterial acid fermentation of com-
plex organic substrates. Acidification, however, enhances volatization of
undissociated fatty acids, precipitates humic-like organics and facilitates
hydrolysis and oxidation of complex organics. Relative large quantities
of acid are also necessary to lower the pH to about 2, causing substantial
dilution of other constituents. Preservation with 40 mg/£ HgCl2 is not
recommended as it is probably not effective. The mercury will be precipi-
tated under anaerobic conditions as mercury sulfide and lose its bacteri-
cidal properties. When results of organic analysis are presented, the time
lag between sample collection and analysis should be stated.
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4.3 SELECTION OF PARAMETERS TO BE MEASURED
The remainder of this manual contains numerous analyses that can be
performed to characterize the leachate sample. When a large number of
samples have to be analyzed it is not feasible to measure all parameters,
and those parameters will be determined that are easy to measure. It is
felt that most information is obtained by measuring conductivity (attributed
by salts and volatile free fatty acids), color or absorbance at 400 nm
(attributed by iron and organics) and pH (a low pH indicates presence of
volatile free fatty acids). When more parameters are to be measured they
should include COD (reflects concentration of organics) and total solids
(reflects presence of organics and inorganics). Especially after the
above five parameters exceed a certain value is it warranted to determine
other parameters such as TOC, free volatile fatty acids, BOD, organic
nitrogen or specific anions and cations.
It is recommended that when an organic parameter such as TOC or organic
nitrogen is measured, the inorganic equivalent is also included such as the
bicarbonate concentration and the ammonia concentration. The ratio organic-
C: (organic-C + inorganic-C) then reflects the degree of biological stabili-
zation of the sample, since acid fermentation followed by methane fermenta-
tion converts the complex organics to free volatile fatty acids, which are
then converted into methane and carbon dioxide. The latter dissolves to
a significant degree into the leachate and is reflected in the increased
bicarbonate concentration. A high ratio would indicate little organic
degradation,while alowerratio would reflect increasing stabilization.
However, it should be realized that the titration method is not applicable
for the bicarbonate determination in leachate since free volatile fatty
acids are also included. The only accurate way is therefore to measure the
inorganic carbon with the duel channel organic carbon analyzer using the
inorganic channel.
The ratio organic-N: (organic-N + ammonia-N) does not represent major
analytical problems and both measurements can be made sequentially with
the Kjeldahl apparatus. The ammonia is first distilled off, whereafter
the organic nitrogen is digested, converted to ammonia and subsequently
distilled off.
4.4 COMPLICATIONS DURING FIELD SAMPLING
The preferred sampling conditions as discussed in the earlier sections
may not always exist in certain field situations. Sampling wells may not
be present, in which case leachate samples, possibly diluted by groundwater,
will have to be collected from an excavated trench at the toe of the fill.
If collection devices are present, the aerobic conditions may have resulted
in the partial degradation of the organics in the leachate. In such a
situation more emphasis will have to be placed on analysis of inorganic
parameters such as chlorides and heavy metals. When the sample containers
are not refrigerated during handling and storage further degradation will
occur. An evaluation in the authors laboratory showed that aerobic condi-
10
-------
tions and storage at roomtemperature caused a 14% COD decrease in 6 days.
Anaerobic conditions at roomtemperature caused a 4% COD decrease, while
anaerobic conditions at 4° C caused a 3% decrease. Deviations of the
recommended procedures, which may occur because of limitations dictated
by field conditions, will affect the outcome of the chemical analysis and
should therefore br recorded together with the results of the chemical
analysis.
11
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SECTION 5
METHODOLOGY OF METHOD EVALUATION
Since most of the leachate studies have been conducted by researchers in
the sanitary or environmental engineering fields, the methods that are used
closely reflect those of Standard Methods (APHA, 1971). Studies between
1960 and 1965 used the llth edition, between 1965 and 1971 the 12th edition
and after 1971 the 13th edition. Laboratories not employing complicated
instruments, sometimes use methods listed by Hach Chemical Company, Handbook
of Mater Analysis (Hach Chemical Company, 1973). Methods used by geologists
are generally those reported in Techniques of Mater Resources Investigation
of the U. S. Geological Survey (U. S. Geological Survey, 1970). Recent
studies use the EPA procedures in Methods for Chemical Analysis of Hater
and Hastes (EPA, 1974) which also contain optional procedures for automated
analysis. Most studies employing automated chemical analysis, however, use
methods recommended by Technicon Industrial Systems, Industrial Methods
(Technicon, 1973).
The different parameters that have been determined in the studies
reported in the literature are listed below. Each section contains a survey
of the different methods used to' analyze a certain parameter, and the obtained
experiences. The method least interferred with by the matrix of the leachate
sample was selected and then evaluated in greater detail in the present
study. The method was evaluated with the standard addition method and by using
progressively increasing dilutions.
5.1 STANDARD ADDITION METHOD
The standard addition method is widely used in chemical analysis when
interferences present in the sample cannot be avoided. An advantage of
this method is that it avoids the necessity of preparing synthetic standards
of a composition similar to that of the sample (Geological Survey,
1970). In this method equal volumes of sample are added to a water blank
and standards containing increasing but known amounts of the test element.
The volume of the blank and the standards must have the same volume to result
in a similar dilution of the sample. The diluted samples containing increasing
amounts of the test element are then analyzed according to the standard
procedures. The obtained values are then plotted on the vertical axis of a
graph while the concentration of the known standards are plotted on the
horizontal axis (Figure 3). When the resulting line is extrapolated to
zero measured concentration, the point of interception of the abscissa is
the concentration of the unknown element. The abscissa on the left of the
ordinate is scaled the same as on the right side, but in the opposite
direction of the ordinate. Since the scale of the ordinate and abscissa
are identical, a line drawn under 45° from the extrapolated point on the
abscissa to the ordinate represents a 100 percent recovery of the added
element. Thus 100 percent of the known amount added to the diluted sample
is recovered. If the actual line connecting the points has a slope lower
than 45° the recovery of the added element is less than 100 percent while a
slope higher than 45° represents a higher than 100 percent recovery. The
12
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-Concentration, mg/Jf
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150 Dilution
(72.5% Recovery)
I'. 100 Dilution
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100 7o Recovery
0.2 0 0.2 0.4 Ofi
Added Concentration Total-P, mg/1
0.8
Figure 3. The Total-P Determination with the Ascorbic Acid
Method in the 1:50 and 1:100 Diluted Leachate
Sample Using the Standard Addition Method
13
-------
actual percentage recovery can be calculated from the tangent of the line
connecting the data points. This is identical to taking the intersect of
the ordinate and dividing it by the extrapolated value on the left side
of the abscissa.
5.2 DILUTION METHOD
In the dilution method the sample is diluted with increasing amounts
of distilled deionized water and analyzed according to the standard pro-
cedures. The obtained concentration is then adjusted for its dilution
effect to give the apparent initial concentration before dilution (Figure
4). The apparent concentration is then plotted vertically and the dilution
factor horizontally. The apparent concentration generally increases at
increasing dilution till it reaches a plateau value. This indicates that
matrix interferences of the sample, which generally result in lower aparent
concentrations, are reduced with increasing dilution. The dilution
associated with this plateau value are then used to determine the other
leachate samples in the batch. At very high dilution the spectrophoto-
meter is not able to record absorbances accurately, resulting in high
apparent concentrations in the initial sample. Comparison of the dilution
method and the standard addition method as evaluated for the total phosphate
determination, showed that the latter is generally more accurate. The
former, however, is easier to administer, and requires less time. Both
the standard addition method and the dilution method require the analysis
of a "sample blank", i.e. the sample in its final dilution containing all
the reagents except the color forming reagent. In the heavy metal analysis
the sample blank is analysed by measuring the broad non specific absorp-
tion at a wavelength bordering the analyte line.
14
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15
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SECTION 6
PHYSICAL PARAMETERS
This section includes determinations that require physical measurements
such as measuring a voltage, a current or a weight. Included in this section
are the determinations of pH, ORP, conductivity and residue.
6.1 pH DETERMINATION
Principle
The pH is the logarithm of the reciprocal of the hydrogen activity in
moles per liter. The pH of leachate from a fill recently generating
leachate will have an acidic pH between 4 and 5 as a result of the predominant
presence of free volatile fatty acids. Biologically more stabilized or "older"
leachate will have a pH between 5 and 8 as a result of the predominant
influence of the bicarbonate buffer system. In those leachate samples the pH
may increase directly after sampling as a result of C02 liberation. All
studies evaluated used the electrometric method employing a glass electrode
and a calomel reference electrode or a combined electrode (Appendix A).
One study used a 10 percent KNOs Orion reference electrode (Fungaroli, 1971).
Interference
The glass electrode is relatively immune to interference from color,
turbidity, colloidal matter and reducing agents. No significant inter-
ference was therefore reported in the studies evaluated.
Recommendations
It is recommended that the pH be determined electrometrically using a
glass electrode and a calomel reference electrode or a combination electrode.
A wide selection of commercially available meters are used for recording.
The temperature at which the recording is made should be stated.
Procedures
"Because of the differences between the many makes and models of pH meters
which are available commercially, it is impossible to provide detailed
instructions for the correct operation of every instrument. In each case,
follow the manufacturer's instructions. Thoroughly wet the glass electrode
and the calomel electrode and prepare for use in accordance with the
instructions given. Standardize the instrument against a buffer solution
with a pH approaching that of the sample, and then check the linearity of
electrode response against at least one additional buffer of a different pH.
The readings with the additional buffers will afford a rough idea of the
limits of accuracy to be expected of the instrument and the technic of
operation." (Standard Methods. 13th Ed., 1971, p. 279)
16
-------
6.2 ORP DETERMINATION
Principle
When the activities of dissolved species in a system differ from
unity the potential observed at equilibrium is termed the Oxidation
Reduction Potential (ORP). Relative oxidizing or aerobic systems gener-
ally have positive values while reducing or anaerobic systems generally
have a negative value. The ORP can be calculated from the concentration
of the redox determining species such as S0
-------
6.3 CONDUCTIVITY
Principle
The specific conductance of leachate reflects the total concentration
of ionic solutes and is a measure of the capacity to convey an electric
current between 2 platinum electrodes each with a surface area of 1 cm2
placed 1 cm apart. In leachate from a fill recently generating leachate,
both inorganic and organic species such as free volatile fatty acids
contribute to the conductivity. Since the conductivity of acids depends
on the degree of dissociation, the conductivity measurement is pH dependent.
In older leachate the conductivity is mainly attributed to Na+, K+ and HC03"
ions and to a lesser extent to fulvic acids; the measurement becomes,
therefore, less pH dependent.
Interferences
Fouling of the electrode surfaces may occur and checks of the indicated
conductance using another cell may be necessary. A chromiurn-sillfuric acid
mixture is effective in cleaning the electrodes. Other solutions as
recommended by the manufacturer of the instrument are also satisfactory.
Previous Studies
Many studies measure this parameter in leachate and report satisfactory
results with the measurement. Some studies that limit the number of chem-
ical tests use the conductivity as the most important parameter to identify
the migration of leachate in groundwater. The conductivity of biologically
stabilized leachate may decrease during seepage through soils as a result
of cation exchange in which Ca++ and Mg is replaced by Na+ but may
increase as a result of nitrification in which NH4+ is converted to N03~
and H+. Most studies use electrodes with a cell constant of 1. A constant
of 0.1 is generally not used since it requires dilution of the sample which
will affect the pH and dissociation of several species.
Recommendations
It is recommended that the conductivity be determined concurrently
with the pH employing a commercially available meter and electrode with a
cell constant of 1. Both the temperature and pH sould be determined as
it effects the results. The results should be reported at the temperature
recommended by manufactures, which is generally 25°C.
Procedures
The instrument must be standardized with a 0.01 m KC1 solution before
daily use. "Dissolve 745.6 mg anhydrous KC1 in freshly boiled double-
distilled water and make up to 1,000 ml at 25° C. This is the standard
reference solution, which at 25° C has a specific conductance of 1,413
micromhos/cm.
lo
-------
Rinse the conductivity cell in the potassium chloride solution and
measure the resistance. Record this value as RKCI• Next rinse the cell
and measure the resistance of the first samples; proceed in the same way
until all the water samples have been measured. Do not measure the resis-
tance of the KC1 solution again unless there is a temperature drift of
more than a few tenths of a degree during the set of measurements. Repeat
the KC1 measurement, however, with every subsequent set of water samples.
The cell constant, C, is equal to the product of the measured
resistance, in ohms, of the standard potassium chloride solution, and
the specific conductance, in mhos per centimeter, of standard solution;
C = RKCI x 0.001413 if the measurement is made at 25° C.
The specific conductance (mho/cm) of the water sample at 25°C is
equal to the cell constant, C, divided by the resistance, in ohms, of the
sample, R , measured at 25° C:
r
Specific conductance = -5-
Rs
It is standard practice to express it in micromhos/cm.
If the temperature of measurement is not exactly 25° C, it may be
more convenient to calculate the specific conductance at 25° C according
to the equation:
1.413 x RKCI
Specific conductance = 5 micromhos/cm
Rs
where RKCI and Rs are measured at the same temperature, preferably near
room temperature, and in the range from 20 to 30° C." (Standard Methods.
13th Ed., 1971, pp. 326-327).
6.4 RESIDUE DETERMINATION
Principle
The residue determination includes the total solids (TS) and volatile
solids (VS). A further differentiation is made between the dissolved
solids (DS) and suspended solids (SS) also defined as nonfilterable and
filterable residues. In both fractions the total and volatile solids can
be determined. The total residue is the weight of the solids left after
evaporation of the water on a steambath and its subsequent drying to con-
stant weight in an oven at 103-105° C. The volatile solids are calculated
from the weight difference between 550° C (for 1 hour) and 105° C. The
residue determinations are not subject to the usual criteria of accuracy
19
-------
since many uncontrolled factors can influence the determination. The
distinction between dissolved and suspended solids is an operational one
since it uses filtration through a filter to differentiate between the
two fractions. The filter can be a glass fiber filter, membrane filter
or ashless filter paper, and may have a pore size of 0.45 u to several
microns.
Interferences
The determination of the total solids can vary due to volatiliza-
tion of part of the organic matter, loss of occluded water and gasses
from heat induced chemical decomposition. The suspended solids deter-
mination is affected by the physical nature of the material in suspen-
sion, the pore size of the filter, and the area and thickness of the mat.
Previous Studies
Most studies determine the total solids and volatile solids since
it is a relatively rapid and simple determination. The general procedure
is used of drying the sample to constant weight at 105° C after which it
is heated at 550° C for 1 hour. Some studies, however, heat to 580° C
or 600° C for 10 minutes to 1 hour (Appendix A). A relatively large number
of studies also determine the suspended solids and most use glass fiber
filters. Only one study used a membrane filter, while one study used air
drying at room temperature (Appendix A).
Evaluation of Method
The TS test was evaluated to determine the effect of drying the
sample at 25° C and 103° C, respectively. Since free volatile fatty acids
comprise a large fraction of the organic matter, the higher drying temp-
erature may result in a lower TS reading. In order to verify this, leach-
ate samples, initially stored in the coldroom (5° C), were dried at 25° C
and at 103° C, respectively and than stored in the disiccator before
weighing. Thereafter, the dried residues were redissolved and analyzed
for COD. The results of these measurements are reported in Table 1 which
shows clearly that drying at 103° C reduces the TS reading as can be seen
by the ratio of TS]03/TS25 of 0.808. A ratio of 1 would indicate no
effect of drying temperature on TS. The COD of the redissolved sample
showed a much smaller influence of the drying temperature. The ratio of
COD1Q3/COD25 was found to be 0.98.
It was also evaluated whether aerobic degradation of the sample would
influence the above results. The data show that the TS-|03/TS25 ratio is
somewhat higher with the aerated sample, i.e. a value of 0.818 versus
0.808 as obtained with the unaerated sample stored at 5° C. However, the
20
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ratio of COD-^/CODgK is lower with the aerated sample. The aerated
leachate sample was then separated into two fractions using a centrifuge
to determine whether the change of these ratios was due to the suspended
solids or dissolved solids. Table 1 shows that both TS and COD ratios
are lower for the soluble fractions as compared to the suspended solids
fraction. The increase in the TS-|03/TS;?5 in the aerated leachate, as
compared to the leachate sample stored in the cold room, is therefore
the result of the increased suspended solids, since the TS-|Q3/TS25 ratio
of the suspended solids is higher than the dissolved solids. A decrease
of the COD ratio of the aerated sample as compared to the stored leachate
sample appears to be due to a change in the soluble organics, and a
relatively higher concentration of the more volatile lower molecular
weight free volatile fatty acids such as acetic acids which are expected
to be found in the aerated sample as a result of microbial degradation
of the higher molecular weight fatty acids such as valeric and caproic
acid in leachate. The above data show that TS is best determined at 103° C,
since a substantial amount of bound water will be removed at this temp-
erature with only 2 percent of the organics volatilized as compared to
25° C. However, after the sample is aerobically degraded, the loss of
volatile matter may reach as high as 6 percent with comparable amounts
of the bound water removed when the drying process is conducted at 103° C,
as compared to 25° C.
The volatile solids (VS), representing the weight loss between 103° C
and 550° C, were evaluated in a similar fashion as the TS test. Figure 5
shows that when the temperature was increased from 550° C to 650° C the
VS value increased by 8 percent. The additional loss of weight above a
temperature of 550° C is attributable to the volatilization of inorganics
such as carbonates, since no more removal of COD was observed. Results
of temperature study on volatile solids measurements for leachate support
procedures outlined by Standard Methods which suggests a furnace tempera-
ture of 550° C for VS determination.
Recommendations
It is recommended that the total solids be determined after drying
to constant weight at 105° C while the volatile solids are determined
from the weight loss at 550° C for one hour. The suspended solids are
best determined using a glass fiber filter and selecting similar temper-
atures as for the total solids. A glass fiber filter is preferred since
it is able to filter a leachate sample in the presence of a high concen-
tration of suspended solids.
Procedure for Total Solids
"Subject the dish to be used in the determination of total residue
to a preliminary drying in an oven at the same temperature intended for
the residue. If ignition of the residue is to be carried out for deter-
mination of fixed total residue, ignite the dish in a furnace for 30 min
at 550° C.
22
-------
0 100 200 300 400 500 600
Temperature, °C
700
Figure 5. Effect of Heating Temperature on the Volatile Solids
Determination when Sample was Heated for One Hour
in a Furnace
23
-------
Choose a volume of sample which will yield a residue between 25 and
250 mg, and preferably between 100 and 250 mg. Estimate the volume to
be evaporated from the specific conductance value.
Pour a measured portion of the well -mixed sample into a weighed
evaporating dish on a steam bath. After complete evaporation of the
water from the residue, transfer the dish to an oven maintained at 103-105° (
Dry to constant weight. Consider constant weight to be attained when not
more than a 0.5 mg weight change occurs between two successive series of
operations consisting of heating, cooling in a desiccator, and weighing.
Allow the dish to cool briefly in air before placing it, while still
warm, in a desiccator to complete cooling in a dry atmosphere. Do not over-
load the desiccator. Provide sufficient room so that all dishes may remain
flat on the desiccator shelf, and no part of a dish touches another dish
or the side of the desiccator.
Weigh the dish as soon as it has completely cooled. Do not allow the
residue to remain overly long in a desiccator because some residues are
very hygroscopic and may remove water from a desiccant that is not
thoroughly dry. Report the increase in weight over the empty dish as
'total residue1 on drying at 103° C in terms of mg/£ and to the nearest
whole number. For results exceeding 1,000 mg/l report only three signifi-
cant figures."
total residue - "* tot
(Standard Methods, 13th Ed., 1971, p. 289).
6.7 Procedure for Fixed or Volatile Residue
"Take the residue produced in 6.4 and ignite in the dish or filter
in a muffle furnace at a temperature of 550° C for 1 hr in order to insure
reproducibility. Have the furnace up to temperature before inserting the
sample.
After ignition, allow the vessels to partially cool in air until most
of the heat has dissipated, then transfer to a desiccator for final
cooling in a dry atmosphere. Do not overload the desiccator. Weigh the
vessel as soon as it has completely cooled. Report the increase in weight
over the empty ignited vessel as 'fixed total residue1, in terms of mg/£
and to the nearest whole number. For results exceeding 1,000 mg/l report
only three significant figures.
,„£• . • . mg fixed residue x 1,000
mg/£ f^xed residue = -S - ^ samp1e - '—
(Standard Methods. 13th Ed., 1971, p. 292-293).
24
-------
Procedure for Fi'ltrable Residue
If the determination is to be made directly by weighing the residue,
subject the filter to a preliminary drying an oven at the same tempera-
ture intended for the sample. Consider 2.5 mg as the minimum amount of
residue to be significant in direct weighing.
"After filtration transfer the filter with its contents to an oven
maintained at a temperature of 103-105° C and dry until constant weight
is attained. Cool briefly in air and transfer to a desiccator to complete
the cooling in a dry atmosphere. Report the increase in weight over that
of the empty filter as 'nonfiltrable residue1 on drying at 103° C in
terms of mg/£ and to the nearest whole number. Also report the type of
filter used.
mg/£ nonfiltrable residue =
where A = mg 'nonfiltrable residue1. (Standard Methods, 13th Ed., 1971,
p. 292).
25
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SECTION 7
ORGANIC CHEMICAL PARAMETERS
Since the objectionable nature of leachate from a recently generating
landfill is caused to a large extent by the dissolved organics such as free
volatile fatty acids, it is important to analyze for these parameters.
In biologically more stabilized leachate the organic matter concentration
is generally low and does not contribute significantly to any odor. The
organics in such samples will only contribute to the color of the sample.
7.1 THE COD DETERMINATION
Principle
The chemical oxygen demand (COD) indicates the quantity of oxidizable
materials that are present in a water sample and is expressed as the oxygen
equivalent of the organic matter that is susceptible to oxidation by a
strong chemical oxidant. A relation exists between COD, TOC and BOD
depending on strength of the leachate and age of the landfill since all
three parameters measure certain aspects of the organic matter. Ratios
of BOD to COD values may be as high as 0.8 for leachate from a recently
generating fill while it may decrease to less than 0.1 for biologically
stabilized leachates. Similarly the COD/TOC ratio may decrease from 3.5
to less than 1 indicating progressing oxidation of the organic matter. These
ratios are subject to considerable variation due to the nature of the solid
waste and climatic conditions.
Interferences
Straight chain aliphatic compounds and acids are not oxidized to an
appreciable extent, but addition of Ag2$04 will increase the oxidation.
When relatively large quantities are added to the sample, HgS04 will have
to be added first, to complex the high chloride concentrations as a soluble
mercuric chloride complex as the choride would otherwise have reacted with
the silver.
Previous Studies
Most studies determine the COD according to procedures outlined in
Standard Methods. The addition of sulfonic acid is generally omitted since
nitrite is generally not present in high concentrations as compared to the
organic substances. HgS04 is sometimes added in larger quantities than
the 0.4 g/20 ml sample as specified in Standard Methods due to the high
chloride content of the sample. Fungaroli (1971) reduced the quantity of
strong sulfuric acid added to the sample from 30 ml to 15 ml. Ott (1974)
increased the dichromate concentration from 0.25 N to 0.5 N and used a
shorter reflux time to reduce the time necessary to run the test. Although
the COD value is generally higher than the BOD, Hughes et_ al_. (1971) noted
on several occasions that the BOD value was larger than the COD. This,
26
-------
however, was the result of the longer incubation time of the BOD test which
was 20 days as opposed to 5 days as recommended by Standard Methods.
Evaluation of the Method
The COD test was evaluated by varyiny four parameters, i.e., the amount
of dichromate added, the concentration of sulfuric acid used, reflux time
and the procedure of acid addition. Figure 6 shows that increasing the
amount of sulfuric acid beyond the 30 ml recommended by Standard Methods
increases the COD value by 7 percent. This increase is larger, i.e. 18
percent when the concentration of dichromate is doubled. However, it is
not recommended to use the larger amount of sulfuric acid since the
condensate which drops down into the heated sample in the flask, does not
mix very well with the sample, and will have a tendency of blowing the content
out of the flask. Increasing the normality of the dichromate is also not
recommended since lower COD values are obtained (Figure 6) due to the higher
decompositions of the dichromate. Also, a larger error will be introduced
due to the high normality of the dichromate. Results of the reflux time
show that most of the organics are oxidized within the first 30 minutes of
refluxing (Figure 7) indicating that the reflux time recommended by Standard
Methods is satisfactory. The effectiveness of the reflux time was also
evaluated by determining the TOC in the COD flask after refluxing. Assuming
that most of the organics were present as acetic acid, it was calculated
that 4.8 percent of the COD was not oxidized. This indicates that a fraction
of the organic matter was highly resistant to oxidation.
The COD test was evaluated with respect to the procedure of acid
addition. The 13th edition of Standard Methods specifically recommends
addition of the acid through the condenser, while such a requirement was not
mentioned in the previous editions. Since most leachate studies in the past
followed the earlier editions, it was important to evaluate this aspect.
Duplicate tests showed that the COD of the sample to which the acid was
added through the condenser was 1.48 percent higher than that of the sample
to which the acid was added directly to the Erlenmeyer flask containing
the 1:20 diluted leachate sample.
Separate experiments were conducted to substantiate the result of the
above findings. A small scrubber containing 5 ml of NaOH was used to
collect the fumes that evolved from the leachate sample. The scrubber
connected to the COD flask, to which the acid was added directly, contained
a TOC of 36.1 mg/1. Using a COD/TOC ratio of 2.67 for acetic acid, it was
calculated that 3.98 percent of the COD finally measured in the sample was
lost throughvolatilization. The TOC of the scrubbing solution connected to
the COD apparatus was found to be 11.2 mg/1 when acid was added through the
reflux condenser. This represents a COD loss of 2.28 percent of the COD
finally measured. On the basis of a material balance using TOC data
obtained from the scrubber, the value of the COD should be 1.70 percent
higher with the acid addition through the condenser. However, on the basis
of the actually measured COD values, the difference was found to be 1.48
percent as reported above, indicating some discrepancy of the two measure-
ments.
27
-------
„ 30,000
o>
E
Q
O
O
20,000
10,000
0 0.25N K2Cr207(Recommended By Standard Methods)
A 0.50NK2Cr20?
Recommended By
Standard Methods
10 20 30 40 50
Amount Of Concentrated Sulfuric Acid, mt
Figure 6. Effect of Amount of Sulfuric Acid and Normality of
Dichromate on the Results of the COD Test
o>
Q
O
O
30,000
20,000
10,000
I
Recommended By
Standard Methods
I
I
Figure 7.
50 100 150
Reflux Time, min
Effect of Reflux Time on the Results of the COD Test
28
-------
For some of the leachate samples analyzed in this lab, the test was
conducted by adding acid and dichromate long before the samples are re-
fluxed. This time lag before refluxing on COD values was thus evaluated.
Results of this study show that when the time lag between reagent addition
and refluxing is one day, the final COD value decreases by an additional
0.6 percent. This additional COD loss increases to 1.9 percent after a
period of 3 days between reagent addition and reflux.
It can therefore be concluded that the most important variables in
the COD test are the amount of acid added and that of dichromate used.
The procedure of acid addition and the time lag between reagent addition
and reflux are less important variables in the COD test. The precision
of the COD test was determined with five replicate samples containing 1000
mg/i lactose solution. A mean of 1058.2 mg/i COD and a standard error of
6.7 mg/l, or 0.63 percent were found in this study. Therefore, the
reported variations of COD data are generally within the accuracy of the
COD test. The study showed that a minimum of 30 mi of concentrated sul-
furic acid should be used with 0.25 N potassium dichromate. The use of
15 mi of concentrated sulfuric acid as opposed to 30 mi may decrease
values by as much as 46 percent. Using a higher dichromate concentration
and shorter reflux time may decrease values by as much as 30 percent.
The Technicon Autoanalyzer may result in slightly lower COD values since
the refluxing takes place for only 25 minutes as compared to 120 minutes
while the quantity of AgS04 catalyst is only 60 percent of that recommended
by Standard Methods. However, this may have been counteracted by the higher
reflux temperature of 145° C and the higher sulfuric acid content which is
10 times higher than recommended by Standard Methods. Chlorides may inter-
fere in the autoanalyzer determination since the quantity of HgSO^ is only
2.5 percent of that recommended by Standard Methods.
Recommendations
It is recommended that the COD method be executed as outlined in
Standard Methods by using 30 mi concentrated sulfuric acid and 0.25 n
potassium dichromate. In the few instances that the COD is less than
100 mg/£ more accurate results are obtained by using the low level COD
in which all reagents are diluted ten times.
Reagents
"Standard potassium dichromate solution. 0.250N: Dissolve 12.259 g
primary standard grade, previously dried at 103° C for 2 hr, in
distilled water and dilute to 1,000 mi.
Sulfuric acid reagent, cone. H2S04 containing 22 g silver sulfate,
per 9-1b bottle (1 to 2 days required for dissolution).
29
-------
Standard ferrous ammonium sulfate titrant, analytical-grade crystals,
0.1 ON! Dissolve 39 g Fe(NH4)2 ($04)2 • 6 HoO in distilled water. Add
20 mi cone. h^SO^., cool, and dilute to 1,000 mi. This solution must be
standardized against the standard potassium dichromate solution daily.
Standardization - Dilute 10.0 mi standard potassium dichromate
solution to about 100 mi. Add 30 mi cone. H2S04 and allow to cool.
Titrate with the ferrous ammonium sulfate titrant, using 2 or 3 drops
(0.10 - 0.15 mi) ferroin indicator.
mi K?Cr?07 x 0.25
Normality = L ^ '
mi Fe (NH4J2 (S04)2
Ferroin indicator solution: Dissolve 1.485 g 1 ,10-phenanthroline-
monohydrate, together with 695 mg FeS04 ' ^ H2^ 1
-------
Dilute the mixture to about 150 ml with distilled water, cool to room
temperature, and titrate the excess dichromate with standard ferrous ammon-
ium sulfate, using ferroin indicator. Generally, use 2-3 drops (0.10-0.15
ml] of indicator. Although the quantity of ferroin is not critical, do
not vary it among samples even when analyzed at different times. Take as
the end point the sharp color change from blue-green to reddish brown, even
though the blue-green may appear within minutes.
Reflux in the same manner a blank consisting of ZO ml distilled water,
together with the reagents.
- (a -
where COD = chemical oxygen demand from dichromate, a = ml Fe(NH4) 2(504)2
used for blank, b = ml FeCNH^CSO^o used for sample, and N = normality
of Fe(NH4)2(S04)2." (Standard Methods, 13th Ed., 1971, p. 497, 498, 499).
7.2 THE TO C DETERMINATION
Principle
A small wastewater sample is vaporized and then oxidized to C02 in a
furnace at 950° C. A carrier stream of pure oxygen removes the C02 from
the furnace and leads it into an infrared analyzer to provide a measure
of the C02- To distinguish between organic and inorganic carbon a separ-
ate sample is heated at 150° C to remove the inorganic carbon in a carrier
stream of pure oxygen which is then determined in an infrared analyzer.
Subtraction of the two measurements provide the value for the total
organic carbon (TOC). Relations have been established between TOC, COD
and BOD. Based on theoretical considerations the COD/TOC cannot exceed
4 while it may decrease to one for strongly oxygenated and biologically
stabilized leachate samples.
Interference
This procedure is only applicable to homogeneous samples which can be
injected into the apparatus reproducibly by means of a microliter syringe.
The needle opening of the syringe limits the maximum size of particles
which may be included in the sample. Lower TOC values are also obtained
when some volatile organics are stripped from the sample and oxidized
during the inorganic carbon determination at a temperature of 150° C.
31
-------
Previous Studies
Several studies use the TOC measurements (Appendix A) in conjunc-
tion with COD to provide a measure of the amount of organic matter present
in leachate. Acidification of the sample is sometimes warranted to
dissolve the suspended ferric hydroxide solids that otherwise would clog
the syringe opening and is also used to preserve the sample.
Evaluation of the Method
The TOC test is a method having fewer complications than the COD
test to determine the amount of organic matter present in leachate samples.
Great care, however, should be taken to get the TOC analyzer in optimum
working condition. If this requirement is not met, the results of TOC
analysis will not be reliable. Procedures developed in this study allow
the adjustment of the TOC Analyzer to a condition which allows the TOC
measurement within the 10 mg/l range with good accuracy and reproducibility
(Figure 8). The maximum error is within ± 1 mg/£ which is in good agree-
ment with that claimed by the manufacturer. The background TOC of the
dilution water, a doubly distilled deionized water, is shown by the inter-
cept at the ordinate (^ 4 mg/£) which agrees well with the values between
3-4 mg/£ TOC determined in many instances in this laboratory. The back-
ground TOC of the dilution water should be subtracted from both the
standard solutions and the diluted leachate samples. This correction
for background TOC of the dilution water has not been emphasized in the
latest edition of Standard Methods (1971).
Loss of accuracy of TOC analysis in the presence of high concentra-
tions of dissolved solids was evaluated by making a TOC mass balance on
a leachate sample obtained from a recently generating solids waste landfill,
The centrifuged sample was fractionated with a 10,000 MW ultrafiltration
membrane. The results of analysis are shown in Figure 9. Figure 9 shows
that it is necessary to correct for the distilled water TOC since the
standard and the leachate sample are made up with distilled water.
Figure 9 also shows that the variation of the recorder height is slightly
more pronounced for the 10,000 MW UF retentate sample than for the
permeate due to the relatively high iron content in the former fraction.
However, the reproducibility of both fractions is very good due to the
high dilution used, which will effectively eliminate any interference.
The inorganic channel generally shows a better reproducibility than the
total carbon channel because it is not interfered by the presence of
suspended solids.
Calculation of the actual TOC concentrations showed that inorganic
carbon contribution was negligible as compared to the organic carbon in
the sample analyzed. The mass balance is th^n made by taking into account
the concentration effect of the UF membrane and the dilution of the per-
meate by the washing of the retentate with distilled water. The result
shows that the adjusted TOC of the fractions comes within 99.9 percent of
32
-------
o>
0)
I
o
Q)
Q.
90
80
70
60
50
40
30
20
10
Sample Size, 20
TOC Of Dilution Water
~4ppm
I I
0
468
TOC,mg/|
10
Figure 8. Calibration Curve of TOC Analyzer for Low Concentration
Ranges
33
-------
o
TJ
CO
8
O
O
O
"c
o
p
o
0>
1
C
2
8
c
o
?
o
0>
c
c
0
-O
*-
0
o
en
c
g
"o
O)
"_E*
5
0)
E
to
T3
(L
C
O)
Q.
E
(0
oo
HI
(O
-C
o
fO
OJ
-a
OJ
> OJ
(O Q
5|
CTt
O)
s-
3
34
-------
the TOC of the original leachate sample, confirming the reliability of
this test. The above results show that the TOC test is an accurate
method if a sufficiently high, dilution of the leachate sample is made to
neutralize interfering suspended solids. The results have to be corrected
for any TOC contributed by the dilution water.
Recommendation
The TOC analysis should be determined according to Standard Methods.
When the analysis is run on samples diluted with distilled water, the TOC
contribution of the distilled water should be taken into account.
Procedures
Instrument operation: The differences between satisfactory analyzers
render impossible the formulation of detailed instructions applicable to
every instrument. Therefore, follow the manufacturer's instructions for
assembly, testing, calibration and operation of the analyzer on hand.
Vary the injected sample size from the normally recommended 20yl to 100-200
yl when an enlarged combustion tube is available.
Sample treatment: When the sample contains suspended solids con-
tributed by iron hydroxide, acidify the sample to disperse the solids.
When the sample contains soil particles filter the sample through a glass
fiber filter and determine the suspended solids concurrently.
Preparation of standard curve: Prepare a standard carbon series of
10, 20, 30, 40, 50, 60, 80 and 100 mg/l with redistilled water by diluting
10, 20, 30, 40 and 50 ml standard carbon solution to 1,000 m£, and 30, 40
and 50 ml standard carbon solution to 500 mi. Inject and record the peak
heights of these standards.
Plot the carbon concentrations of the standards in mg/l versus the
corrected peak height in millimeters on rectangular coordinate paper.
Ascertain the sample concentrations from the corrected peak heights of
the samples by reference to this calibration curve.
Calculate the corrected peak height in millimeters by deducting the
blank correction in the standards and samples as follows:
Corrected peak height in mm = A - B
where A = peak height in mm of the standards or sample, and B, peak
height in mm of the blank.
Apply the appropriate dilution factor when necessary.
35
-------
7.3 VOLATILE ACIDS DETERMINATION
Principle
The 12th and 13th editions of Standard Methods recommend the column
partition chromatographic method to determine free volatile fatty acids in
water samples. This method has superseded earlier distillation and direct
titration methods. An acidified water sample is adsorbed on a column of
inert granular material after which the organic acids are extracted from
the column with chloroform-butanol solvent, which is then titrated with
NaOH.
The volatile acid test is a very important test for leachate since
free volatile fatty acids such as acetic and butyric acid comprise the
majority of the organics present in a leachate sample obtained from a
recently generating landfill. Since this organic fraction can be removed
by anaerobic or aerobic bacteria, the organic acid test is a measure of
the biodegradability of leachate and as such may be a more accurate test
than the BOD. In biologically stabilized leachate samples volatile acids
are generally not detected while the sample still may have a considerable
COD or TOC or color.
Interferences
The Standard Methods recommend the tentative Column Partition Chrom-
atographic Method for determining free volatile fatty acids. The only
interferences are caused by other organic acids, such as pyruvic,
a-ketoglutaric and succinic acids as they adsorb to silicic acid and
are eluted off with the butanol-chloroform mixture together with the
other free volatile fatty acids. These acids may be present in leachate,
judging from the relatively high concentration of carbonyl groups in the
500 M'iJ UF permeate. These compounds are excreted as intermediates and
are eventually removed by further biological degradation of leachate.
The other method for fatty acid analysis that has been used is the
hydroxylamine test. In this test, acid is esterified with alcohol, the
alcohol group is displaced by the hydroxylamine which then gives a colored
complex with ferric iron. Since any carboxyl group will respond to such
reaction, carboxyl groups from the refractory humic and fulvic acids will
contribute to the final reading. This interfering effect becomes more
noticeable when the concentration of these refractory organics is rela-
tively large with respect to the fatty acid concentration, which occurs
in biologically stabilized leachate. Hughes e_t aj_. (1971), for example,
found relatively high concentrations of carboxyl groups in old leachates
with respect to the COD. Since the BODc values were relatively low in
these samples with respect to the COD, little or no biodegradable fatty
acids would be expected, indicating that in such instances nonfatty acid
carboxyl groups are measured.
36
-------
Previous Studies
Most studies use the column partition chromatographic method for
analysis of organic acids and satisfactory results have generally been
obtained when the test is executed with sufficient care (Appendix B).
One study used both steam distillation and gas liquid chromatography
but no comparisons were given. One study used the gas liquid chromato-
graph for organic acid analysis. Two studies used the hydroxylamine test
to determine the presence of carboxyl groups.
Evaluation of the Method
The results of analysis with the column partition chromatographic
method and the hydroxylamine test with a polluted leachate sample having
an initial COD of 31,200 mg/i showed that relatively high concentrations
of fatty acids were present (Figures 10 and 11). Comparison of extra-
polated results obtained with these two methods showed that the column
partition method gave a 4.76 percent higher fatty acid concentration than
the hydroxylamine test in the 1:20 diluted sample, while it was 27.8
percent higher in the 1:40 diluted sample. The latter test had the highest
percentage recovery (85.7 percent versus 74 percent with column partition
method in the 1:20 dilution) when standard amounts of acetic acid were
added to the diluted sample. Section 5.1 explains the details of the
standard addition method.
The Standard Methods reported a more than 95 percent recovery
efficiency for fatty acid concentrations in excess of 200 mg/£ as
determined with the column partition method. The low recoveries
obtained with leachate samples i.e. 74 percent and 61 percent in the
1:20 and 1:40 diluted sample, respectively, therefore indicates the
presence of interfering substances. It also means that the test has to
be run with standard amounts of fatty acids added to the sample, in
order to determine the percentage recovery. Evaluation of Figure 10
also shows that decreasing the dilution from 1:40 to 1:20 increases the
percentage recovery but decreases the calculated concentration of
fatty acids from 18,400 mg/£ to 17,600 mg/£ obtained in the 1:40 and
1:20 dilution, respectively. These results therefore indicate that the
sample should be diluted as little as possible to increase the percen-
tage recovery as long as the measured concentrations are below 5000 mg/£.
The hydroxylamine test, similar to the column partition method,
showed the highest calculated concentration corresponding with the lowest
recovery. However, since the discrepancy between the two methods is
smallest for the least diluted leachate sample, the hydroxylamine test
should be run on the least diluted sample, as long as the concentration
is below 5000 mg/£.
37
-------
2500
2000
o»
o
o
<5
8
0)
or
1500
1000
500
100 % Recovery
1120; 74 %
Recovery
/
Extrapolated Concentration, mg/J
Measured With
Standard Addition
500
O
O
:40; 61 % Recovery
1000
500
0
500
1000
1500
Added Concentration, mg/f
Figure 10. The Organic Acid Determination with the Column Partition
Chromatographic Method
38
-------
2000
1500
8 1000
c
o
o
T3
0)
o
o
500
I!20 Dilution
(85.7 7o Recovery)-
Extrapolated
Concentration, mg/J?
Measured With
Standard Addition
«*, °H
',40 Dilution
(94.5 7o Recovery)
100 7o Recovery
000
500
0
500
1000
Added Concentration, mg/J?
Figure 11. The Organic Acid Determination with the Hydroxylamine
Test
39
-------
Recommendations
It is recommended that the volatile organic acids be determined with
the column partition chromatographic method as listed in Standard Methods
and that standard amounts of acid be added to determine the recovery of
the metfnd. When the recovery of the added amount is less than 100 per-
cent the obtained values will have to be adjusted using the recovery
factor as outlined in Section 5.1.
Reagents
"Silicic acid, specially prepared for chromatography, 50-200 mesh:
Remove fines by slurrying the acid in distilled water and decanting the
supernatant after settling for 15 min. Repeat the process several times.
Dry the washed acid in an oven at 103° C until absolutely dry, then
store in a desiccator prior to use.
Chloroform-butanol reagent, CB25: Mix 300 mi reagent-grade chloro-
form, 100 mi n-butanol, and 80 mi 0.5 N H2S04 in a separatory funnel and
allow the water and organic layers to separate. Drain off the lower
organic CB25 layer through a fluted filter paper into a dry bottle.
Thymol blue indicator solution: Dissolve 80 mg thymol blue in 100 mi
absolute methanol.
Phenolphthalein indicator solution: Dissolve 80 mg phenolphthalein
in 100 mi absolute methanol.
Sulfuric acid: Cone., reagent-grade
Standard sodium hydroxide titrant, 0.02 N: Dilute 20 mi 1.0 N
NaOH stock solution to 1 liter with absolute methanol. Standardize the
solution against 0.0200N potassium biphthalate solution which has been
prepared by dissolving 4.085 g anhydrous KHCsH^, and diluting to the
mark of a 1-liter volumetric flask with C02-free distilled water."
(Standard Methods, 13th Ed., 1971, pp. 578-579; p. 51)
Procedure
"Centrifuge enough leachate to obtain 10-15 mi clear sample in a
small test tube or beaker. Add a few drops of thymol blue indicator
solution, then cone. H2S04, dropwise until definite color change from
red to thymol blue (pH = 1.0-1.2).
Column chromatography: Place 12 g silicic acid in a Gooch or fritted-
glass crucible and apply suction to pack the column. With a pi pet,
distribute 5.0 mi of the acidified sample as uniformly as possible over
40
-------
the surface of the column. Apply suction momentarily to draw the sample
into the silicic acid, releasing the vacuum as soon as the last portion
of the sample has entered the column. Quickly add 65 mi CB25 reagent to
the column and apply suction. Discontinue the suction just before the
last of the reagent enters the column. Use a new column for each sample
to be analyzed.
Titration: Remove the filter flask and purge the eluted sample with
nitrogen gas or C02-free air immediately before titration.
Titrate the sample with standard 0.02 N NaOH reagent to the phenol -
phthalein end point, taking care to avoid aeration of the sample. Nitrogen
gas or C02-free air delivered through a small glass tube may be used to
purge and mix the sample and to prevent contact with atmospheric C02
during titration.
Blank: Prepare a blank composed of 5.0 mi acidified (^$04) distilled
water, place on column, extract with 65 ml of 0625 reagent, and titrate in
a similar manner.
Total organic acids (mg/i as acetic acid) = (a"b x 60,000
where a = mi of NaOH titrant used for sample, b = mi of NaOH titrant used
for blank, and N = normality of NaOH titrant." (Standard Methods. 13th
Ed., 1971, p. 579).
7.4 THE TANNIN AND LIGNIN DETERMINATION
Principle
Aromatic hydroxyl groups are oxidized and reduce tungstophosphoric
and molybdophosphon'c acid to form a blue color which is measured at 700
nm. The color reaction is similar to that of the phosphate determination
and is also able to detect very low concentrations. The test reflects
the presence of refractory organics in biologically stabilized leachate
and its relative contribution to the organic matter in leachate increases
with age of the landfill.
Interferences
Other easily oxidizable substances such as reduced metal ions, sul-
fides and nitrite may give a similar reaction in this test and caution
should therefore be exercised in evaluating the results. The largest
interference is caused by ferrous iron and 2 mg/£ will give a color
equivalent of 1 mg/£ tannic acid.
41
-------
Previous Studies
One study used the tyrosine-Hach method to measure aromatic hydroxyls
in leachate and generally reported a relative increase parallel to the
stabilization of the refuse. Another study reported satisfactory results
with the tannin lignin test.
Evaluation of the Method
An evaluation of the method was conducted by Chian and DeWalle (1975)
which showed that the color is best measured at 620 as compared to 700 nm.
The Intensity of the colored product depends on whether the OH group is
in the ortho, meta or para position. When the aromatic ring has three OH
groups, one of the groups may not participate in the reaction.
Recommendations
It is recommended that this test be measured according to Standard
Methods.
Reagents
"Tannin-lignin reagent: dissolve 100 g sodium tungstate dihydrate,
O/(.'2H20, 20 g molybdophosphoric acid (also called phosphomolybdic
acid), 20Mo03-2H3P04-48H20, and 50 mi 85 percent phosphoric acid, HsPO/j,
in 750 mi distilled water. Boil the liquid under reflux for 2 hr; cool
and make up to 1 liter with distilled water.
Sodium carbonate solution: dissolve 200 g Na2C03 in 500 mi warm
distilled water and dilute to 1 liter to form a saturated solution. Keep
in a rubber-stoppered bottle.
Stock solution: weigh 1.000 g of the tannic acid. Dissolve in
distilled water and dilute to 1,000 mi.
Standard solution: dilute 10.00 mi of 50.00 mi stock solution to
1,000 mi with distilled water to form a solution containing 10.0 yg or
50.0 yg active ingredient per 1.00 mi." (Standard Methods. 3rd Ed.,
1971, p. 347).
Procedure
"Add 2 mi tannin-lignin reagent to 50.0 m£ of clear sample and mix
well. After 5 min add 10 mi sodium carbonate solution and mix thoroughly.
Wait 10 min for color development. Make photometric readings against a
reagent blank prepared at the same time. Use the following guide for the
instrumental measurements at the wavelength of 620 nm:
42
-------
Tannic Acid Lignin
in 62-m£ in 62-m£ Light
Final Volume Final Volume Path
yg ug cm
50-600 100-1,500 1
10-150 30- 400 5
(Standard Methods. 13th Ed., 1971, p. 347).
7.5 THE ORGANIC NITROGEN DETERMINATION
Principle
In the presence of sulfuric acid, potassium sulfate and mercuric
sulfate catalyst, the ami no nitrogen of many organic materials is converted
to ammonium sulfate, after which the ammonia is distilled under alkaline
conditions by the addition of sodium hydroxide and sodium bisulfite and
collected in a boric acid solution. While the Standard Methods (1971)
recommend addition of 50 mi digestion reagent to 300 mi sample, EPA (1971)
recommend 100 mi digestion reagent for 500 mi of sample. Both recommend
digestion till $03 fumes are given off and the solution turns pale yellow.
In the automated procedure the sample is digested with the same reagents
as used in the Kjeldahl method whereafter the ammonia concentration is
determined with the phenate method measuring the blue indophenol color.
Interferences
The only interferences that are encountered may be due to the incom-
plete oxidation of the organic nitrogen to ammonia.
Previous Studies
Most studies selected the Kjeldahl method with digestion, distillation
and titration of the ammonia collected in the borate solution with no major
difficulties being reported. Only two studies measured the organic nitrogen
with the automated procedure, (Appendix A and B).
Evaluation of the Method
The evaluation of the organic nitrogen test (Figure 12) showed nearly
100 percent recovery with low concentrations of bovine albumin added to
the sample. This high recovery is the result of the high buffer concen-
tration which does not cause any pH decrease during the distillation, and
the low ammonia concentration present after digestion of the organic nitrogen,
43
-------
o>
c
o
c
CD
O
O
O
T>
CD
t-
CD
I
CD
cr
100 7o Recovery
KID Dilution
Extrapolated
Concentration, mg//
Measured With
Standard Addition
1120 Dilution
20 30 40
50
Added Concentration , mg/JJ
Figure 12. The Organic Nitrogen Determination with the
Kjeldahl Method
44
-------
At higher concentrations of the standard additions, however, the recovery
decreases progressively. This is probably due to a pyrolytic charring of
the sample which then forms black insoluble humin products that enmesh
organic nitrogen present in the sample. The charring was not noticeable
at the low additions but became more pronounced at higher concentrations,
indicating that the Kjeldahl test may not be able to detect the organic
nitrogen at concentrations above 30 to 50 mg/l depending on the dilutions
used. However, at tKe concentrations encountered in leachate from the UI
lysimeter and at the dilutions employed no interferences were noted. The
charring was found to increase with increasing amounts of digestive reagent
used. When the amount of digestive reagent was increased from 50 to 75 and
100 mi respectively, the organic-N concentration in the 1:10 dilution
decreased from 18.2 to 18.1 and 16.7 mg/£, respectively. Therefore, 50 mi
digestion reagent was selected as the amount that still gave satisfactory
results. Since the duration of the digestion as outlined in Standard
Methods is inconclusive an evaluation of the digestion time showed that
a period of 30 minutes (after the start of the boiling) is satisfactory
since it results in the highest concentration (Figure 13).
Recommendations
It is recommended that the organic notrogen be determined with the
Kjeldahl method as outlined in Standard Methods with 50 mi digestion
reagent added to 300 mi sample while digesting for 30 minutes.
Reagents
All the reagents listed for the determination of the ammonia nitrogen
are required, plus digesting reagent: Dissolve 134 g potassium sulfate,
«2S04 in 650 mi ammonia-free distilled water and 200 mi cone. HgSCty. Add,
with stirring, a solution prepared by dissolving 2 g red mercuric oxide,
HgO, in 25 mi 6N ^$04. Dilute the combined solution to 1 liter. Keep
this solution at a temperature above 14° C to prevent crystallization.
Phenolphthalein indicator solution.
Sodium hydroxide-sodium thiosulfate reagent: dissolve 500 g NaOH
and 25 g Na2$2®3 ' ^2^ in ammonia-free distilled water and dilute to
1 liter.
Mixed indicator solution: dissolve 200 mg methyl red indicator in
100 mi 95 percent ethyl or isopropyl alcohol. Dissolve 100 mg methylene
blue in 50 mi 95 percent ethyl or isopropyl alcohol. Combine the two
solutions. Prepare monthly.
Indicating boric acid solution: dissolve 20 g 1^803 in ammonia-free
distilled water, add 10 mi mixed indicator solution, and dilute to 1 liter.
Prepare monthly.
45
-------
o»
E
c
o
c
0)
u
c
o
o
0)
o
0)
10
20 30
Digestion Time, min.
40
Figure 13. Effect of Digestion Time on the Concentration of
Organic-N Finally Measured in the 1:10 Dilution
46
-------
Standard sulfuric acid tltrant, 0.02 N: prepare and standardize as
directed in Alkalinity, section 8.4. For greatest accuracy, standardize
the titrant against an amount of sodium carbonate which has been incor-
porated in the indicating boric acid solution to reproduce the actual
conditions of the sample titration. A standard acid solution, exactly
0.0200 N, is equivalent to 280 yg N per 1.00 mi." (Standard Methods.
13th Ed., 1971, p. 245).
Procedure
"Selection of sample volume: Place a measured sample into an 800-iu£
Kjeldahl flask. Determine the sample size from the following tabulation:
Organic Nitrogen
in Sample, mg/l
Sample Size, mi
0-1
1-10
10-20
20-50
50-100
500
250
100
50.0
25.0
If necessary, dilute the sample to 300 mi and neutralize to pH 7.
Ammonia removal: Add 25 mi phosphate buffer solution to a sample.
Add a few glass beads or boiling chips and boil off 300 ml. If desired,
distill this fraction and determine the ammonia nitrogen. Alternatively,
if ammonia has been determined by the distillation method, use the
residue in the distilling flask for the organic nitrogen determination.
Digestion: Cool and add carefully 50 mi digestion reagent (or sub-
stitute 10 mi cone. ^504, 6.7 g K^SO^ and 1.5 mi mercuric sulfate solution)
Then digest for an additional 30 min. Allow flask and contents to cool;
dilute to 300 mi with ammonia-free water and add 0.4 ml phenolphthalein
indicator solution and mix. Tilt the flask and add, carefully approximately
50 mi hydroxide-thiosulfate reagent to form an alkaline layer at the bottom
of the flask.
Connect the flask to the steamed-out distillation apparatus and shake
the flask to insure complete mixing. Add more hydroxide-thiosulfate reagent
in the prescribed manner if a red phenolphthalein color fails to appear at
this stage.
Distillation: Distill and collect 200 mi distillate below the surface
of 50 mi boric acid solution. Use plain boric acid solution when the
ammonia is to be determined by nesslerization and use indicating boric
acid for a titrimetric finish. Extend the tip of the condenser well below
47
-------
the level of boric acid solution and do not allow the temperature in the
condenser to rise above 29° C. Lower the collected distillate free of
contact with, the delivery tube and continue distillation during the last
minute or two to cleanse the condenser.
Final ammonia measurement: Determine the ammonia by titrating the
ammonia in the distillate with standard 0.02 N sulfuric acid titrant until
the indicator turns a pale lavender.
Blank: Carry a blank through all the steps of the procedure and
apply the necessary correction to the results.
•
where D = mt H?SO,
blank."
mi HpSO/i titration for sample and E = mi H£S04 titration for
(Standard Methods. 13th Ed., 1971, p. 246).
48
-------
SECTION 8
INORGANIC CHEMICAL PARAMETERS
The inorganic pollutants may constitute approximately half of the
total pollutants in recently generated leachate but represent the major
part in biologically stabilized leachate. Several of the inorganic pollu-
tants are conservative and are not rapidly removed during soil attenuation.
8.1 THE CHLORIDE DETERMINATION
Chloride is one of the major anions in leachate and is sometimes used
as a tracer for leachate monitoring in soils because of its inert character.
All methods are based on the formation of a complex or precipitate by a
metal chloride. The EPA (1974) recommends the mercuric nitrate method
based on the formation of the soluble mercuric chloride complex for waste-
water samples and the ferricyanate method for automated analyses. Technicon
(1973) also uses this method, in which the mercury, added as mercuric thio-
cyanate, forms a complex with chlorides. The liberated thiocyanate then
reacts with ferric ions to form a colored cyanide complex.
Interferences
Of the three chloride methods listed in Standard Methods, the argento-
metric method and the mercuric nitrate method are most susceptable to inter-
ferences. The argentometric method uses AgNOs to precipitate the Cl~ and
the red Ag2Cr04 complex to indicate the endpoint of the titration. This test
is interfered with by more than 10 mg/1 iron since it will mask the color of
the endpoint (APHA, 1971).
The more tedious mercuric nitrate method uses Hg N03 to form HgCl2
while the endpoint is indicated by the purple mercuric diphenyl carbazone
complex. This test is interfered with by more than 10 mg/1 ferric,
chromate, and sulfite ions. According to Ulmer (1974) the test is also
interfered by zinc and ferrous ion in excess of 100 mg/1, copper ion in
excess of 50 mg/1 and ferric ion in excess of 20 mg/1 in the final dilution
of the leachate sample.
Previous Studies
An evaluation of two leachate samples tested with the mercuric nitrate
method at a dilution of 1:10 and with one standard addition of 25 mg/1 Cl~
in the final dilution, showed that 96.8 percent and 100 percent was recovered,
respectively (Ulmer, 1974). This would indicate that at these dilutions no
interferences are encountered for these specific leachate samples. Strongly
polluted and colored leachate samples, however, may not experience such a
good recovery due to the interferences listed above. For that reason the
potentiometric method is recommended by Standard Methods for samples that
have a strong color. In addition, the method is less tedious than the
49
-------
mercuric nitrate method and many samples can be determined in a short
period of time.
Most studies analyzing leachate selected the mercuric nitrate method
while some studies used the argentometric method which is based on the
formation of a AgCl precipitate after addition of AgNt^. Three studies
used the potentiometric determination when strong color would interfere
with other methods. Two studies used the automated ferri cyanide method.
Evaluation of the Method
Since many constituents present in leachate such as iron, zinc and
sulfide interfere with the mercuric nitrate and argentometric method, the
potentiometric method was evaluated for leachate, The method is based on
the titration of the sample with AgNOs, while the decrease of the chloride
concentration or the increase of the Ag+ concentration after the chloride is
precipitated as AgCl, is measured with a Cl electrode or Ag/AgCl electrode,
respectively.
Chlorides in polluted water samples can be determined with the solid state
chloride electrode since common ions such as sulfate, nitrate and phosphate
do not interfere. The solid-state electrode also permits measurements in
the presence of oxidizing agents such as Fe3+ and Cu^+. Interference is caused
by ions that complex the chloride and NH4+ at a concentration of 12 percent
of that of chloride will result in a 1 percent error (Orion, 1970). In the
leachate sample analyzed, the Nfy"1" value was 86 percent of the Cl value
indicating that some interference may occur.
The procedures for chloride analysis using the potentiometric method
establish first a calibration curve between the chloride concentration and
the electrode potential. The data in Figure 14 show a linear decrease in
potential at increasing concentrations. At very high concentrations the
decrease may be more than linear on a normal-log plot since the activity
of the chloride ion becomes substantially less than the corresponding concen-
tration.
The chloride concentration in the leachate sample can be determined by
both the direct reading and the titration method both employing standard
additions. In the first method, increasing amounts of chloride are added
to the sample, after which a direct potentiometric reading is made and the
resulting value is converted into actual concentration with the aid of the
calibration curve. The results in Figure 15 indicate that both the 1:2 and
1:4 dilution experienced a 24 percent and 26 percent enhancement, respectively.
Extrapolation of the values obtained eliminated this effect, and a chloride
concentration of 700 mg/1 in the undiluted leachate sample was calculated.
The second method employed titration with AgNOs of leachate samples
containing increasing amounts of Cl". The endpoint of the titration is
indicated by the inflection point of the potentiometric reading. Figure 16
shows a titration curve of a 1000 mg/1 chloride solution and the 1:2 and 1:4
diluted leachate samples indicating that a very distinct inflection point
50
-------
140
130
.5
0)
2
0)
•o
120
110
.
LJ
100
90
80
50
100
500
1000
Concentration Of Ch,mg/5l
Figure 14. Calibration Curve of the Chloride Electrode
51
-------
0>
E
700
600
500
•£ 400
0)
o
c
o
O
TJ
O>
w
0>
>
o
o
Q>
cr
300
200
100
l!2 Dilution
(I247o Recovery)-
— Extrapolated
Concentration,
— O
r~-
Measured With
Standard Addition
', 4 Dilution
(I267o Recovery)
-100 % Recovery
300 200 100 0 100 200
Added Concentration Of CI~,mg/JP
300
400
Figure 15. Chloride Determination Using Direct Potentiometric
Readings in the Diluted Leachate Sample
52
-------
400
c
0)
£
•o
o
v.
"o
to
LL)
300
200
100
1:4
Diluted
Leachote
1:2 Diluted
Leachate
lOOOmg/f CI'
5 10 15 20 25
Titrant Volume Of 0,14 N AgN03, mj
30
Figure 16. Titration Curve of 1000 mg/l Cl" Solution and a 1:2
and 1:4 Diluted Leachate Sample
53
-------
can be obtained. In order to determine the normality of the AgN03
solution, solutions of increasing Cl~ content are titrated till the
inflection point. Figure 17 shows that this results in a calculated
normality of 0.138 N as compared to a normality calculated from the
weighting of the dry AgNO, of 0.14 N.
Analysis of the leachate samples showed that approximately 100
percent of the amount of chloride added is recovered. The measurements
at the 1:2 and 1:4 dilution resulted in a Cl~ value in the original
leachate sample of 680 mg/£ (Figure 18). As 100 percent of the added
amount of Cl~ is recovered and no enhancement is observed, the obtained
value of 680 mg/£ is more accurate than the 700 mg/l calculated from
the direct readings using the standard addition method. Since no
enhancement or depression occurs as a result of the presence of pollu-
tants in leachate, the leachate sample can be titrated directly and no
standard additions have to be made. Since a single titration to the
inflection point is less time consuming than the direct potentiometric
readings on leachate samples containing increasing standard additions,
the titration method is recommended for leachate analysis. Also, it
was observed that 5-10 minutes were required to stabilize the potentio-
metric reading when the concentration was determined directly, while the
rapid increase near the inflection point was observed without any delay.
On the other hand the amplitude of oscillation was smaller at high
concentrations and larger near the inflection point. However, this
did not cause any inaccuracy in the determination.
Recommendations
It is recommended that in biologically stabilized leachate samples
in which the color does not cause any interference, the chloride deter-
mination be conducted with the mercuric nitrate method while in strongly
polluted leachate the chlorides be determined with the potentiometric
titration method.
Reagents
"Standard sodium chloride solution, 0.0141 N - Dissolve 8.243 g
NaCl, dried at 105° C, in distilled water and dilute to exactly 500 ml.
Dilute 50.0 ml of this solution to exactly 1,000 ml. The final solu-
tion contains 0.500 mg Cl per 1.00 ml.
Nitric acid, cone.
Standard silver nitrate titrant, 0.014 N - Dissolve 2.40 g AgNOs in
distilled water and dilute to 1,000 ml.
Sulfuric acid, 1 + 1
54
-------
0)
E
I
S
12
10
8
m = 0.0205 ml Titrant/mgA
Ci- Normality Of AgN03
Solution = 0.138 N
I
100 200 300 400 500
Ch Concentration,mgA
Figure 17. Determination of Normality of AgNO, Solution
55
-------
700
600
500
o
S 400
o
o
T3
0)
I
O
O
0>
or
300
200
100
l',2 Dilution
(100% Recovery)-
Extrapolated
Concentation, mg/J?
CM
X
Measured With
— Standard Addition
I! 4 Dilution
(100% Recovery)
300 200 100 0 100 200
Added Concentration Of Cl~~, mg/JP
300
Figure 18. The Chloride Determination by the Standard Addition
Method Using Titration to Inflection Point in the
Diluted Leachate Sample
56
-------
Hydrogen peroxide, 3Q percent
Sodium hydroxide. 1 N" (Standard Methods, 13th Ed., 1971, p. 378).
Procedure
"Inasmuch as the various instruments that can be used in this deter-
mination differ in operating details, the manufacturer's instructions should
be followed. Necessary mechanical adjustments should be made. Then, after
allowing sufficient time for warm-up (10 min), the internal electrical
components are balanced to give an instrument setting of 0 mV or, if a
pH meter is used, a pH reading of 7.0.
Place 10.0 mi standard NaCl solution in a 250 mi beaker, dilute to
about 100 mi, and add 2.0 m cone. HNC^. Immerse the stirrer and the
electrodes in the solution.
Set the instrument to the desired range of millivolts or pH units.
Start the stirrer.
Add standard AgNO? titrant, recording the scale reading after each
addition. At the start, large increments of AgNOs may be added; then,
as the end point of the reaction is approached, smaller and equal incre-
ments (0.1 or 0.2 mi) should be added at longer intervals, so that the
exact end point can be determined. Determine the volume of AgNOs used
at the point at which there is the greatest change in instrument reading
per unit addition of AgN03- Adjust the AgNOs titrant to the same
normality as the NaCl solution; 1 .00 mi = 0.500 mg Cl .
of
Pipet exactly 100.0 mi of sample, or an aliquot containing not more
than 10 mg chloride, into a 250 mi beaker.
In the presence of organic compounds, sulfite or ferric iron and
sulfide acidify the sample with ^$04, using litmus paper. Boil for
5 min to remove volatile compounds. Add more H^SO,, if necessary, to
keep the solution acidic. Add 3 mi ^2^2 an^ b01'^ *or 15 min, adding
chloride-free distilled water to keep the volume above 50 mi. Dilute
to 100 mi, add NaOH solution dropwise until alkaline to litmus, then
10 drops in excess. Boil for 5 min, filter into a 250 mi beaker, and
wash the precipitate and paper several times with hot distilled water.
This step can be omitted when it is shown that it does not result in
higher measured chloride concentrations.
57
-------
Add cone. HMOs dropwise until acidic to litmus paper, then 2.0 mi
in excess. Cool and dilute to 100 m if necessary. Immerse the stirrer
and the electrodes in the sample and start the stirrer. After making
the necessary adjustments of the instrument according to the manufac-
turer's instructions, set the selector switch to the appropriate setting
for measuring the difference of potential between the electrodes.
Complete the determination by titrating. For the most accurate
work, a blank titration should be made by carrying chloride-free distilled
water through the procedure.
mg/£ ci" = (A-B) x N x 35.45 x 1,000
where A = mi AgNOo, B = mi blank, N = normality of titrant, and D = mi
sample." (Standard Methods. 13th Ed., 1971, p. 378-379).
8.2 THE SULFATE DETERMINATION
Principle
Sulfate is present in relatively high concentrations in leachate
generated from a recently leaching fill, but will decrease in concentra-
tion under anaerobic conditions in which it is reduced to sulfide, which
will then precipitate heavy metals. The sulfate can be determined gravi-
metrically as the BaS04 precipitate or turbidimetrically. In the gravi-
metric method BaCl2 is added to the sample and after digestion the BaS04
precipitate is filtered and weighed after drying at 105° C or ignition
after 1 hour at 800° C. In the turbidimetric method the turbidity of
the BaS04 precipitate is measured against a standard. The automated EPA
method (1974) uses barium chloranilate that when added to the sample
releases the Ba++ which then precipitates as BaS04 while the released
acid chloranilate forms a red color. Technicon (1973) uses Bad2 which
is added to the sample while the excess Ba reacts with methyl thymol blue
to give a blue colored complex.
Interferences
Suspended matter and silicates are precipitated and filtered together
with the BaS04 precipitate. This will lead to relatively high readings,
while incorporation of alkali metals in the sulfate precipitate frequently
yield low results. Heavy metals may also restrict the complete precipi-
tation of the barium sulfate. The turbidimetric method is interfered by
color and suspended matter. High concentrations of Ca++, Mg++ and Fe++
interfere by precipitating the chloranilate in the EPA method (1974) or
react with methylthymol blue in the Technicon method and are therefore
58
-------
first removed by passing through an ion exchange column. However, due
to organic matter chelation and formation of ferrihydroxide colloids this
removal is not always successful.
Previous Studies
Most studies selected the gravimetric method with or without ignition
of the residue. A significant number of leachate analyses (Appendix A and
B), generally conducted by consulting firms, use the turbidimetric method
despite the strong interferences of the suspended matter and color of the
leachate. Wilson (1972) noted that this method could not detect concentra-
tions below 4 mg/£. One study uses the atomic absorption technique while
one study uses the methyl thymol blue method.
Evaluation of the Method
The gravimetric method specifies that the measurement of the BaSO/i
precipitate is conducted after digestion, filtration and drying. The dried
residue can be heated to 800° C to expel occluded water or to remove
colloidal organics. However, since this ignition step complicates the
procedure, the method was first evaluated without the heating at 800°C.
The sample was first acid digested at pH 4 at boiling temperature.
The digestion was continued until all the brown colloids of ferric hydrox-
ide in the leachate had disappeared. After addition of the warm BaCl2 a
precipitate was formed. The precipitate was digested at 80° C for both
2 and 18 hours.
It was found that the digestion of the BaS04 precipitate had to be
proceeded for at least 18 hours to form a readily filterable precipitate.
Extended digestion also reduced the amount of the precipitate in the sample
blank i.e. the leachate sample with all the reagents added, except the
BaCl2. When the digestion was extended from 2 hrs to 18 hrs, the precip-
itate in the sample blank decreased from 26.5 mg/l to 10.5 mg/£ with the
1:2 diluted sample. The 1:2 dilution gave a precipitate some 30 times
higher than that of the 1:4 diluted sample blank indicating that the acid
to leachate ratio has to be sufficiently high or the leachate sufficiently
dilute in order to reduce the amount of suspended solids in the digested
leachate sample. Low dilutions of the leachate sample should also be
avoided, since the time for filtration becomes very long (20-30 minutes)
as a result of the high concentration of precipitate. Also there is an
increased tendency for the solids to adhere to the wall of the filter
holder.
Evaluation of the standard addition method with the 1:2 and 1:4
diluted leachate samples showed that the solids in the leachate caused a
slight enhancement of the sulfate concentration by 6 percent and 2 percent,
respectively (Figure 19). This again confirmed the earlier conclusion
59
-------
400
300
V.
E
.o
^
o
o
o
•g
o
o
0>
cr
200
100
112 Dilution
(106% Recovery)-
I'. 4 Dilution
(102% Recovery)-
Extrapolated
Concentration, mg/Jf
§00
Measured With
Standard Addition
o>
ro
ii
CM
x
in
iri
in
—100 % Recovery
150
100
50
0
50
100
!50
200
Added Concentration Of Sulfate, mg/l
Figure 19. The Sulfate Determination with the Gravimetric Method
in the 1:2 and 1:4 Diluted Leachate Samples
60
-------
that low dilutions should be avoided. The 2 percent enhancement in the
recovery of sulfate with 1:4 diluted sample also shows that it is not
necessary to dry the residue at 800° C for the accuracies generally
desired in leachate analysis.
Recommendations
It is recommended that the gravimetric method be selected for sulfate
analysis as opposed to the turbidimetric method. The automated methods
are applicable only when the color and cations are sufficiently removed.
Reagents
"Methyl red indicator solution: Dissolve 100 mg methyl red sodium
salt in distilled water and dilute to 100 mi.
Hydrochloric acid, 1+1.
Barium chloride solution: Dissolve 100 g BaCl2 • 2H20 in 1 liter
distilled water.Filter through a membrane filter or hard-finish filter
paper before use; 1 mi of this reagent is capable of precipitating
approximately 40 mg $04.
Silver nitrate-nitric acid reagent: Dissolve 8.5 g AgN03 and 0.5
me cone. HNOs in 500 mi distilled water." (Standard Methods, 13th Ed.,
1971, pp. 331-332).
Procedures
"Precipitation of barium sulfate: Adjust the sample to contain
approximately 50 mg of sulfate ion in a 250 mi volume. Adjust the acidity
with HC1 to pH 4.5-5.0, using a pH meter or the orange color of methyl
red indicator. Then add an additional 1 to 2 mi HC1. Lower concentra-
tions of sulfate ion may be tolerated if it is impracticable to concentrate
the sample to the optimum level, but in such cases it is better to fix the
total volume at 150 mi. Heat the solution to boiling and, while stirring
gently, add warm barium chloride solution slowly until precipitation appears
to be complete; then add about 2 mi in excess. If the amount of precipi-
tate is small, add a total of 5 mi barium chloride solution. Digest the
precipitate at 80-90° C, preferably overnight.
Preparation of filters:
1. Silica or porcelain crucible - Dry to constant weight in an oven
maintained at 105° C or higher, cool in a desiccator, and weigh. Constant
weight is defined as a change of not more than 0.5 mg in two successive
operations consisting of heating, cooling in a desiccator, and weighing.
61
-------
2. Fritted-glass filter - Dry as in 1.
3. Membrane filter - Place the filter on a piece of filter paper
or a watch glass and dry to constant weight in a vacuum oven at 80° C,
while maintaining a vacuum of at least 64 cm of mercury, or in a con-
ventional oven at a temperature of 103-105° C. Cool in a desiccator and
weigh the membrane only.
Filtration and weighing: Filter the barium sulfate at room tempera-
ture. Wash the precipitate with several small portions of warm distilled
water until the washings are free of chloride, as indicated by testing
with silver nitrate-nitric acid reagent. If the membrane filter is used,
add a few drops of anticreep solution to the suspension before filtering
and also to the wash water to prevent adherence of the precipitate to the
holder. Dry the filter with precipitate by the same procedure used in
the preparation of the filter. Cool in a desiccator and weigh.
mg BaSO. x 411.5
m9/£ S04 = m£ sample
(Standard Methods, 13th Ed., 1971, p. 332-333).
8.3 THE PHOSPHATE DETERMINATION
Principle
Phosphate is generally present in the form of orthophosphates, con-
densed phosphates and organical.ly bound phosphates. In the phosphate
analysis the specific phosphorus form is converted after digestion to
soluble orthophosphate which is then determined colorimetrically. The
specific phosphorus form can be separated into dissolved or particulate
phosphorus by filtering through a 0.45 y membrane. Orthophosphates are
those phosphates that respond to the colorimetric test without prelim-
inary hydrolysis or oxidative digestion. The condensed phosphates are
those that are acid hydrolyzed at 100° C. Organic phosphates are those
that are converted to orthophosphate after oxidative destruction or
digestion of the organic matter.
The perchloric acid digestion method is the most drastic, dangerous
and time consuming method, followed in complexity by the nitric acid-
sulfuric acid method. The persulfate method is the simplest but should
be evaluated for its efficiency. Most colorimetric methods are based on
the formation of a blue colored complex when molybdate reacts with phos-
phate in stannous chloride, ascorbic acid or aminonaphthol sulfonic acid,
respectively. EPA (1974) recommends the persulfate digestion followed
by the ascorbic acid colorimetric method. For automated procedures they
also recommend the ascorbic acid method. Technicon (1973) autoanalyzers
62
-------
used the ascorbic acid method but replaced the persulfate digestion with
concentrated sulfuric acid digestion. For early models, Technicon recom-
mended the aminonaphthol sulfonic acid method.
Total phosphate and to a lesser extent orthophosphate is an important
parameter to be measured in leachate since aerobic biological treatment
of leachate requires relatively large quantities of phosphate that some-
times have to be supplied to the treatment unit. Sufficient phosphate is
generally available to sustain anaerobic biological processes. Phosphates
present in leachate may reach surface waters and stimulated nuisance
algal growth.
Interferences
According to Standard Methods the vanadate and SnCl2 method are
interfered with by more than 100 mg/£ Fe2+ and 1000 mg/£ Fe3+, Ca2+,
Mg2+, Na+, K+ and NH4+, which are often present in those concentrations
in leachate. The ascorbic acid method is generally not interfered by
these substances. High iron concentrations, however, may result in an
iron phosphate precipitate that may settle in the bottom of the test tube.
The aminonapthol sulfonic acid method is also relatively free of inter-
ferences as compared to the other methods, and only nitrite and sulfide,
generally not present in high concentrations, cause interference {ASTM,
1969).
Previous Studies
None of the previous studies used the perchloric acid digestion
and prefer the sulfuric acid-nitric acid digestion followed by the
method. Recent studies generally use the persulfate digestion. The
State Water Resources Control Board of California accomplished digestion
by pressure cooking in an autoclave (Appendix A). Foree and Cook (1972)
dried the sample with MgCl£ and heated the residue at 600° C for 10
minutes. Fungaroli (1971) used the aminonaphthol sulfonic acid method
when high concentrations of organic matter were present. Otherwise he
used the SnCl2 method, but did not specify the concentration above which
he used the former method. Pohland (1972) first used the Hach method
but later selected the more accurate aminonaphthol sulfonic acid method.
The aminonaphthol sulfonic acid method was evaluated by Ulmer (1974)
for a 1:10 diluted Boone County leachate sample after addition of a
standard amount of 1 mg/£ of both organic and inorganic phosphate. It
was found that leachate generally gave a slightly enhanced recovery of
organic phosphates, since the recovery of barium fructose 6-phosphate
increased from 86.3 percent to 86.7 percent, of 3-adenylic acid increased
from 91.3 percent to 92.6 percent when compared with the recovery in
distilled water. On the other hand, the recovery of glycerophosphate
decreased from 99.6 percent to 98.6 percent. The simultaneous evaluation
63
-------
of the vanadomolybdophosphoric acid and stannous chloride methods showed
that no reliable results could be obtained.
The recovery of inorganic phosphate was slightly reduced in leachate
since 10Z percent was recovered fn water and 100 percent in leachate. No
evaluation was made, however, of the digestion procedure to convert the
organic phosphates to ortho-phosphate. Only one dilution was evaluated
and one standard addition was tested. In addition, the method has not
been used in many studies since it is not listed in Standard Methods.
A comparison of the stannous chloride method, the vanadate yellow
method and the ascorbic acid method using sodium glycerophosphate as a
standard, showed that ascorbic acid method gave results 6 percent higher
than the stannous chloride method and 1 percent higher than the vanadate
yellow method (Kaylor, 1971). Using one standard addition, Kaylor (1971)
noted a 94 percent recovery of the vanadate yellow method using quench
water.
Evaluation of the Method
As the ascorbic acid method is listed in Standard Methods and is
relatively free of interferences, this method was selected for evaluation.
The ortho-P results showed that very high recoveries were observed when
increasing amounts of KH2P04 were added to the 1:4 and 1:6 diluted
leachate samples (Figure 20). In both cases 100 percent of the amount
added was recovered, a result similar as obtained by Ulmer (1974) with
aminonaphthol sulfonic acid. Although the recoveries were very high,
a slight reduction at higher dilutions was noted since the 1:4 dilution
resulted in an extrapolated value of 0.09 mg/l or 0.36 mg/£ in the
undiluted leachate, while the 1:6 dilution gave an extrapolated value
of 0.055 mg/l or 0.33 mg/£ in the undiluted sample, which is 8 percent
lower than the 1:4 dilutions. Related studies in this laboratory showed
that increasing dilutions caused a more rapid oxidation of the iron to
the ferric form which then may precipitate ortho phosphates, causing a
relative reduction in its concentration at higher dilutions. The sample
should therefore be kept anaerobic and as little dilution as possible
should be used.
A very important aspect of the total-P determination is the digestion
step in which the organic phosphates are coverted to the ortho form.
Recent studies have shown that the less tedious persulfate digestion is
preferred above the more rigorous sulfuric acid-nitric acid digestion as
long as the method gives good recovery. Increasing amounts of persulfate
were therefore added to the sample diluted to 140 mi. The results in
Figure 21 show that increasing values are obtained by increasing the
amount of digestion reagent. A noticeable shoulder, however, is observed
at a concentration of 400 mg/100 ml sample, and further increase of the
measured concentration is probably due to enhancement of the reading by
the digestion reagent itself. The amount of 750 mg/100 ml sample as
recommended by Standard Methods should therefore be reduced to 400 mg/100
64
-------
«K
•>x
e
0_
c
o
0)
o
c
o
o
-o
0>
k_
0>
>
o
o
0)
0.7
0.6
0.5
0.4
0.3
11 4 Dilution
(I007o Recovery)-
— Extrapolated
Concentration, mg/i
Measured With
Standard Addition
116 Dilution
(I007o Recovery)
Ql 0 O.I 0.2 0.3 0.4
Added Concentration Ortho-P, mg/j?
Figure 20. The Ortho Phosphate Determination with the
Ascorbic Acid Method in 1:4 and 1:6 Diluted
Leachate Samples
65
-------
1^
o
tp
o
Q)
Q.
O
C/)
10
d
O
0>
a
u—
0
c
o
<
1
-------
mi when analyzing leachate. A substantial dilution effect was also
observed since the 1:50 dilution resulted in a concentration of 13.5
mg/£ in the undiluted leachate sample while the 1:100 dilution gave
17.5 mg/l.
Evaluation of the digestion time (Figure 22) showed that a 30 minute
digestion time in the autoclave at 15 psi and 250° C is sufficient to
hydrolyze all the organic phosphate. A similar dilution effect was
observed in that the 1:100 dilution resulted in a calculated value of
16.5 mg/l in the original leachate sample while the 1:250 dilution gave
a result of 32 mg/l.
In order to determine the effect of different dilutions the standard
addition method was used in the 1:50 and 1:100 dilution using DNA which
consists of organic P for 9.3 percent of its weight, and added in increas-
ing amounts to the sample. Figure 23 shows that a substantial depression
of 27.5 percent was observed for the 1:50 dilution which was reduced to
17 percent in the 1:100 dilution. Extrapolation of the observed values
resulted in a calculated value of 19.5 mg/£ for the 1:100 dilution and
16 mg/l for the 1:50 dilution indicating that the standard addition
method in the 1:50 dilution negates only part of the interference.
The last phase of the evaluation therefore consisted of the deter-
mination of the optimum dilution for measuring the total phosphate.
Tests were run on leachate samples of increasing dilutions. The results
in Figure 24 show that the calculated total P values in the leachate
reach a plateau value of 19 mg/£ up to a dilution of 1:200, indicating
that at this dilution the interferences in the leachate have been diluted
out. A further rise at 0.095 mg/£ is attributed to the inability of the
test to give a proportionally decreasing color intensity at decreasing
concentrations. The Standard Methods listed 0.01 mg/l as the lower limit
of this test which is 10 times lower than that found in the present study.
Recommendations
It is recommended that the aminonaphthol sulfonic acid or the
ascorbic acid method be used to measure total-P concentration in leachate
employing the persulfate digestion. The amount of recommended persulfate
digestion reagent is 400 mg/100 ml sample while the digestion time recom-
mended by Standard Methods is sufficient to hydrolyze the P. The ortho-P
test as determined by the ascorbic acid method does not experience signifi-
cant interference and should be run on the anaerobically stored leachate
samples after as little dilution as possible. In order to obtain reliable
results, a standard addition curve as shown in Figure 22 be established or
a progressive dilution curve be made as shown in Figure 23, for the total
P determination. Such steps are not necessary for the ortho-P determination.
67
-------
c
3
O
E
Recommended By
Standard Methods
0
Not Put In -
Autoclave
10 20 30
Put In Pressurized Autoclave
Time, min.
40
50
60
Figure 22. Effect of Digestion Time on the Result of the Total
P Determination
68
-------
a.
i
I
o
o
0)
o
o:
1.0
0.8
0.6
0.4
0-2
Extrapolated
-Concentration, mg/J?
Measured With
Standard Addition
o>
CO
1
150 Dilution
(72.57o Recovery)
1100 Dilution
(83% Recovery)
100 % Recovery
I I
0.2 0 0.2 0.4
Added Concentration Total-P, mg/l
0.8
Figure 23. The Total-P Determination with the Ascorbic Acid
Method in the 1:50 and 1:100 Diluted Leachate
Sample Using the Standard Addition Method
69
-------
joj
I/Dm
9|duios u|
d-!Di°l iO lunouuv
70
-------
Reagents for the Persulfate Digestion
"Phenol phthalein Indicator solution.
Sulfuric acid solution: Carefully add 30Q ml cone. ^04 to approx-
imately 600 mi distilled water and then dilute to 1 liter with, distilled
water.
Potassium persulfate solution: Dissolve 2.7 g ^2^Q ^n ^°° m ^
distilled water. Prepare daily.
Sodium hydroxide, 1 N." (Standard Methods, 13th Ed., 1971, p. 526).
Procedures for the Persulfate Digestion Employed in the Total P
Determination
"Take 100 mi or a suitable aliquot of thoroughly mixed sample. To
each 100 mi sample or aliquot diluted to 100 mi, add 1 drop (0.05 mi)
phenolphthalein indicator solution. If a red color develops, add sulfuric
acid solution dropwise to just discharge the color. Then add 1 mi sul-
furic acid solution and 15 mi potassium persulfate solution.
Boil gently for at least 90 min, adding distilled water to keep the
volume between 25 and 50 mi. Alternatively, heat for 30 min in an auto-
clave or pressure cooker at 15-20 psi. Cool, add 1 drop (0.05 mi) phenol-
phthalein indicator solution, and neutralize to a faint pink color with
sodium hydroxide solution. Restore the volume to 100 mi with distilled
water." Determine the total phosphorus present in the sample with the
aminonaphthol sulfonic acid method (Ulmer, 1974) or the ascorbic acid
method listed below. Hhen the digestion step is omitted, these tests
measure the ortho-P content of the sample. (Standard Methods, 13th Ed.,
1971, p. 526).
Reagents for the Ascorbic Acid Method Employed in the Ortho-P
Determination
"Alcohol, ethyl (95 percent) or isopropyl.
Sulfuric acid solution, 5 N: Dilute 70 mi cone. ^04 with distilled
water to 500 mi.
Antimony potassium tartrate: Dissolve 4.3888 g K(SbO)C4H405 • 1/2 H20
in 200 mi distilled water. Store in a dark bottle at 4° C.
Ammonium molybdate solution: Dissolve 20 g (1^4)^07024 • 4^0 in
500 mi distilled water. Store in a plastic bottle at 4° C.
Ascorbic acid, 0.1 M: Dissolve 1.76 g ascorbic acid in 100 mi dis-
tilled water. The solution is stable for about a week if stored at 4° C.
71
-------
Combined reagent: Mix the above reagents in the following propor-
tions for 100 m£ combined reagent: 50 mi 5 N sulfuric acid, 5 mi antimony
potassium tartrate, 15 mi ammonium molybdate solution, and 30 mi ascorbic
acid solution. Allow all reagents to reach room temperature before they
are mixed, and mix in the order given. If turbidity forms in the combined
reagent after the addition of antimony potassium tartrate or ammonium
molybdate, shake the combined reagent and let ft stand for a few minutes
until the turbidity disappears before proceeding. The reagent is stable
for at least 1 week if stored at 4° C.
Stock phosphate solution:
Standard phosphate solution: Dilute 50.0 mi stock phosphate solution
to 1,000 mi with distilled water to form a solution containing 2.00 yg P
per 1.00 mt." (Standard Methods, 13th Ed., 1971, p. 532-533).
Procedure for the Ascorbic Acid Method Employed in the Total P
Determination
"Treatment of sample: Pipet 20.0 mi clear sample into a clean, dry
test tube or a 125-m£ erlenmeyer flask. Add mi ethyl or isopropyl
alcohol. Mix thoroughly. Because curves prepared with ethyl alcohol
are slightly different from those prepared with isopropyl alcohol, use
the same alcohol in treating samples and standards. Add 1 mi combined
reagent. Mix thoroughly and allow to stand 10 min for color development
before reading in a spectrophotometer at a wavelength of 880 nm or a
filter photometer equipped with a red color filter.
Correction for turbidity or interf erring color: Natural color of
water generally does not interfere at the high wavelength used. In the
case of highly colored or turbid samples, prepare a blank by adding all
the reagents except ascorbic acid and antimony potassium tartrate to the
sample. Subtract the absorbance of the blank from the absorbance of each
of the unknown samples.
Preparation of calibration curve: Prepare individual calibration
graphs from a series of six standards within the phosphate ranges. Use a
distilled water blank with the combined reagent to make the photometric
readings for the calibration curve. Plot absorbance vs phosphate con-
centration, which should form a straight line passing through the origin.
Test at least one phosphate standard with each set of samples.
= mg P x 1,000 „
mi sample
(Standard Methods. 13th Ed., 1971, p. 533).
72
-------
8.4 ALKALINITY AND ACIDITY
Principle
The alkalinity of a water is the capacity to accept protons and is
determined by titrating the sample with strong mineral actd to a speci-
fied endpoint. It thus determines quantitatively the ability of a given
sample to neutralize strong acids. In leachate from a recently generat-
ing fill, where the pH is acidic most of the alkalinity is due to the
buffering capacity of partially dissociated free volatile fatty acids,
and carboxyl groups of complex organics. In biologically stabilized
leachate where the pH is generally neutral or slightly alkaline, the
alkalinity is contributed by the carbonate and bicarbonate species as a
result of the dissolution of the C02 gas generated during the methane
fermentation.
The acidity of a water is the capacity to donate protons and is
determined by titrating the sample using strong mineral base, to a speci-
fied endpoint. In leachate from a recently generating fill where the pH
is acidic, most of the acidity is due to undissociated free volatile
fatty acids, dissociated ammonia and other proton donors. In biologically
stabilized leachate the acidity is mainly due to bicarbonate species and
to a lesser extent due to dissociated ammonia. Therefore, direct rela-
tions are anticipated between alkalinity and acidity and the contributing
cations and anions mentioned above. Since several constituents contribute
to the alkalinity and acidity, these tests only give a very general idea
of the magnitude of the pollutants and are therefore somewhat comparable
to the total and volatile solids test and the conductivity measurement,
although they yield less information concerning the leachate character-
istics. The measurement is important when the pH of the leachate has to
be adjusted to provide optimum chemical and biological treatment.
In unpolluted waters the Standard Methods recommend titration end-
points at pH 8.3 and between 57l and 4.5 depending on the magnitude of
the alkalinity. In polluted waters it recommends an arbitrary endpoint
of 8.3 (phenolphthalein endpoint) and 3.7 (methyl orange endpoint) unless
a potentiometric titration curve indicates a distinct inflection point
which can be employed and the endpoint should then be specified with the
analysis. From the titration curve the inflection point can be determined,
whereafter the amount of acid or base, expressed as CaCC^ equivalent,
can be calculated. The potentiometric titration is also to be used for
colored or turbid waters where difficulties arise in determining a color
indicator endpoint.
The EPA (1974) recommends pH endpoints of 8.2 and 4.5 which differs
from the 8.3 and 3.7 as recommended by Standard Methods. The automated
procedure of EPA (1974) uses methyl orange dissolved in a pH 3.1 buffer
as a colorimetric test and is therefore subject to color interferences
from the leachate. A similar method is used by Technicon (1973).
73
-------
Interferences
Standard Methods indicates that the acidity and alkalinity determin-
ation is not only restricted to bicarbonate species but is also contributed
by other weak acids or bases and hydroxides. The test therefore only
indicates general properties of the leachate and cannot be used for the
quantitative determination of specific species.
Previous Studies
Most investigators selected 4.5 or sometimes 4.3 and 4.2 as the
endpoint for the alkalinity determination although Standard Mehtods does
not recommend so. Although Standard Methods does not recommend so for
colored samples some leachate analyses, generally conducted by commercial
laboratories, used colorimetric tests. Several studies determined the
titration curve and used the observed inflection point (Appendix A).
However, they did not specify in their results the value of the selected
pH, as is recommended in Standard Methods. One study stated that no
inflection point existed.Qasim (1965) presented actual titration curves
and showed inflection points at a pH of 3.8 and 7.2.
A comparison of the alkalinity determination using the potentio-
metric method and the methyl orange endpoint titration showed that con-
siderably lower results were obtained with the latter method due to
strong color and turbidity interferences (Hughes et^ a]_., 1971).
Evaluation of Method
Titration curves were run on leachate samples of different strength
obtained from landfills of different ages to determine their inflection
points. Results in Figure 25 show that the higher the COD of the polluted
samples, the larger the amount of strong acid is required to reduce the
pH to the inflection point of 3.2. This inflection point corresponds to
the pH of the highest derivative of the titration curve for the most
polluted samples. Since the weak free volatile fatty acids with pK
values around 4.8 corresponding to the pH of the lowest derivative of the
titration curve are major constituents in leachate, it explains the low
inflection points with the polluted leachate samples.
The amount of equivalents necessary to increase the pH from 3.2 to
4.8 should be equal to the equivalents of half of the free volatile fatty
acids present in the solution. Since the latter amount is more than that
calculated from the gas chromatographic determination (GC), it is sug-
gested that other weak acids, such as phosphoric acid, silicic acid, and
fulvic acid, and weak bases, such as ferric hydroxide, and zinc hydroxide
also contribute to the alkalinity in this pH region. The titration curve,
can therefore, not be used to determine the fatty acid concentration, and
other methods such as the GC and the column partition chromatographic
method are more applicable.
74
-------
Figure 25 also shows that the less polluted leachate samples, the
inflection point increases to pH 4.6 since the alkalinity is now mainly
determined by the carbonate and bicarbonate species. The bicarbonate
alkalinity has a reported inflection point of 5.1 for alkalinities of
about 30 mg/£, pH 4.8 for 150 mg/l and pH 4.5 for 500 mg/l. The effect
of a decreasing fatty acid concentration as measured by GC on the pH of
the inflection point is shown in Figure 26. This indicates that the pH
of the inflection point may be used indirectly to internally check the
fatty acid data.
The acidity determination as shown in Figure 25 should be run to a
pH of 7.6 for high strength leachate samples and 8.9 for less polluted
samples corresponding to the measured inflection points. At a pH of
7.6 all of the free volatile fatty acids are dissociated while at a pH
of 8.9 all C02 is converted to bicarbonate. Other weak acids and weak
bases also contribute to the acidity.
If bicarbonate and carbonate alkalinity are desired, than the sample
should be measured for Total Carbon with the Total Carbon Analyzer before
and after removal of the inorganic carbon (N£ stripping at pH of 2 or
C02 removal at 100° C).
Recommendations
It is recommended that alkalinity and acidity determinations be
made potentiometrically on the undiluted samples and that the endpoints
be used as determined from the titration curve. These endpoints should
be specified in reporting the results of the analysis.
Reagents for the Acidity Test
"Carbon dioxide-free distilled water: Prepare all stock and standard
solutions, and dilution water for the standardization procedure, with
distilled water which has a pH of not less than 6.0. If the water has
a lower pH, it should be freshly boiled for 15 min and cooled to room
temperature. Deionized water may be substituted for distilled water
provided that it has a conductance of less than 2 micromhos/cm and a
pH greater than 6.0."
Standard sodium hydroxide titrant. 0.02 N: Dilute 20.0 mi IN NaOH
with C02~free distilled water to 1 liter. Store in a tightly rubber-
stoppered pyrex glass bottle protected from atmospheric C0£ by a soda-
lime tube. For best results, prepare weekly. Standardize the solution
against 0.0200 N potassium biphthalate solution which has been prepared
by dissolving 4.085 g anhydrous KHCsH/^OA, and diluting to the mark of a
1-liter volumetric flask with C02-free aistilled water. Alternatively,
the alkali may be standardized against standard 0.02 N HC1 or H2S04 made
75
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up for tfie alkalinity tests. Perform the standardization exactly as the
typical acidity titration using the identical volumes of final solution,
and the same time interval for tfie determination. A standard NaOH solu-
tion, exactly 0.0200 N, is equivalent to 1.00 mg CaCOs per 1.00 mi."
(Standard Methods, 13th Ed., 1971, p. 51).
Procedures for the Acidity Test
"Titrate with standard 0.02 N NaOH until the inflection point of the
titration curve as shown in Figure 25.
Acidity as mg/i CaC03 = A x N x 5Q'QQQ
ml sample
where A = mi NaOH titrant and N = normality of NaOH." (Standard Methods,
13th Ed., 1971, p. 52).
Reagents for the Alkalinity Test
"Carbon dioxide-free distilled water: Prepare all stock and stan-
dard solutions, and dilution water for the standardization procedure,
with distilled water which has a pH of not less than 6.0. If the water
has a lower pH, it should be freshly boiled for 15 min and cooled to
room temperature. Deionized water may be substituted for distilled water
provided that it has a conductance of less than 2 micromhos/cm and a pH
greater than 6.0.
Standard sulfuric acid or hydrochloric acid titrant, 0.02 N: Prepare
stock solutions approximately 0.1 N by diluting either 8.3 mi cone. HC1
or 2.8 mi cone. HoS04 to 1 £. Dilute 200 mi of the 0.1 N stock solution
to 1 t with COg-free distilled water. Standardize the 0.02 N acid against
a 0.0200 N sodium carbonate solution which has been prepared by dissolving
1.060 g anhydrous Na2C03 (primary standard grade), oven-dried at 140° C,
and diluting to the mark of a 1 £ volumetric flask with COp-free distilled
water. Alternatively, the acid may be standardized against standard 0.02
N NaOH prepared for the acidity test. Perform the standardization exactly
as the typical alkalinity titration, using the identical volumes of final
solution, sodium thiosulfate, and the same time interval as for the sample
determination.
For the best results, take for standardization a volume of 0.0200 N
sodium carbonate solution which approximates the average alkalinity of
the water samples normally encountered in the given laboratory. A stand-
ard acid solution, exactly 0.0200 N, is equivalent to 1.00 mq CaCOo per
1.00 mi. (Standard Methods, 13th Ed., 1971, p. 54).
78
-------
Procedures for the Alkalinity Test
"Titrate with standard 0.02 N standard acid to the inflection point
of the titration curve as shown in Figure 25, and record the volume of
acid titrant.
as ^/£ CaC03 *
where B = mi standard acid titrant and N = normality of standard acid
treatment. When the alkalinity of sample is so large that more than an
equal volume of titrant is used to reach the equivalent point, the
normality of the titrant should be increased." (Standard Methods, 13th
Ed., 1971, p. 55).
8.5 THE NITRATE DETERMINATION
Principle
Nitrate will generally be present in low concentrations in leachate
for a recently generating fill but will increase in concentration after
further stabilization of the refuse when organic nitrogen is converted
to ammonia nitrogen which under oxidizing conditions is further converted
into nitrate.
Nitrate is a difficult determination in the presence of interfering
ions and all methods listed in Standard Methods for analysis of polluted
waters are therefore tentative.The phenol disulfonic acid method produces
a yellow color (measured at 410 nm) between nitrate and phenol disulfonic
acid. The brucine-sulfanilic acid method, based on the reaciton between
nitrate and brucine, also results in a yellow color measured at 410 nm.
The chromotropic acid method is also based on the formation of a yellow
colorimetric product measured at 410 nm when nitrate reacts with 4, 5-
dihydroxy-2, 7-naphthalene disulfonic acid. The ultraviolet spectro-
photometric method measures directly the absorbance at 220 nm while in
the zinc reduction method the nitrates are reduced to nitrite which is
then determined with the nitrite method.
The EPA (1974) recommends both the brucine method and the cadmium
reduction method, while Technicon (1973) uses the copper-cadmium reduc-
tion method.
Interferences
The yellow color of the phenol disulfonic acid method is interfered
with by more than 10 mg/£ chlorides, while yellow colored materials should
be absent, which makes the method less applicable to leachate (APHA, 1971).
79
-------
The yellow color of the brucine sulfanilic acid method is generally not
interfered by high salt concentrations, but ferrous and ferric iron will
give a positive enhancement, while organic matter also gives some inter-
ference (APHA, 1971). The yellow color of the chromotrophic acid method
is interfered by certain oxidants, yellow colored organic matter and
certain heavy metals.
The ultraviolet spectrophotometric method is only applicable to un-
polluted samples. The method is of a less accurate nature since the
variable organic matter interference is only partially corrected by
measuring the absorbance at the compensating wavelength of 275 nm (APHA,
1971). The zinc reduction method is interfered by reducing and oxidizing
substances such as ferric ions and other heavy metals, while organics
and suspended soldis interfere by coating the column. The cadmium reduc-
tion method is subject to some of the interferences listed for the zinc
reduction method.
Previous Studies
Mao and Pohland (1973) reported that the nitrate concentrations were
initially determined with the specific ion electrode and colorimetrically,
but that strong matrix interferences were encountered due to the presence
of high iron and chloride concentration. These problems, however, were
eliminated with the use of a Technicon Autoanalyzer using hydrazine as a
reducing agent and measuring the formed nitrite. The Solid and Hazardous
Waste Research Laboratories noted that the Cd reduction method as used in
Technicon Autoanalyzers did not give satisfactory results due to coating
of the column by iron and organic matter (Appendix A). The County of
Sonoma and Emcon Associates (1973) found that the brucine test did not
always determine nitrate concentration accurately since dissolved organic
matter, iron and strong oxidizing and reducing substances were found to
interfere with the test. The interferences were reduced by subtracting
from the final readings the value obtained from the sample to which all
the reagents were added except the brucine sulfanilic acid. Qasim (1965)
used both the brucine method and the aluminum reduction method but did
not indicate whether the two methods gave different results. Foree and
Cook (1972) used the standard addition method for determining the nitrate
concentration with the specific ion electrode after precipitation of the
chloride. Most studies, however, use the brucine method (Appendix A).
In order to compare the last two tests, both the nitrate electrode and
the brucine method were evaluated in the present study.
Evaluation of Methods
Comparison of the two methods showed that the nitrate electrode gave
80
-------
better results than the brucine sulfanilic acid method. The results of
the former test, shown in Figure 27 indicate recoveries of 116 percent and
118 percent in the 1:25 and the 1:50 dilution. Figure 28 shows that the
potential variation is sufficiently large to determine small differences
in concentration. The readings obtained without any N03-N added to the
sample were generally higher than obtained through the standard addition
method. The first reading in the 1:50 diluted sample was 1.32 mg/1 which
is 164 percent higher then calculated with the standard addition method
i.e. 0.50 mg/1. The difference in the 1:25 dilution was less pronounced
than in the 1:50 dilution and the first reading without N03-N addition
was 51 percent higher than calculated from the standard addition method.
It is expected, however, that this difference will decrease with lower
dilution and that reliable results will be obtained when the nitrate concen-
tration is determined directly in the leachate sample without any dilution.
The nitrate value obtained as a result of the test i.e. 25 mg/1 is relatively
high as compared to values reported in the literature, indicating that previous
studies may have underestimated nitrate concentrations.
The colorimetric nitrate test gave results less reliable than obtained
with the electrode. The sample would undergo a color change from light green
to yellow brown when dilutions were made for the nitrate test, probably as
the result of the oxidation of the iron and other metals present in the
leachate. The yellow brown color absorbs at the same wavelength as the
color reagent of the test thereby causing strong interference. The relative
color change was more pronounced at the higher dilutions and may well explain
the low recovery of 59 percent (Figure 29) observed in the 1:50 dilution. At
the lower dilution of 1:25 the sample apparently oxidized less rapidly since
the recovery was 82 percent. The value of 22 mg/1 obtained with this test is
slightly lower than the 25 mg/1 obtained with the electrode, and is probably
due to the interferences of the colorimetric test.
Recommendations
It is recommended that nitrates be determined with the specific ion
electrode instead of the brucine method. It is preferable to measure the
nitrates with the electrode in the undiluted sample. Standard amounts
should be added to the sample to determine the recovery of the method.
When the brucine method is used the suspended solids and color may be
removed with a massive lime dosage of 5000 to 10,000 mg/1 Ca(OH)2-
Aluminum hydroxide is not as effective as a coagulant.
Reagents for the Nitrate Electrode Method
"Stock potassium nitrate solution: Dissolve 721.8 mg anhydrous KN03
in distilled water and dilute to 1,000 ml. This solution contains 100 mg/1
N.
Standard potassium nitrate solution: Dilute 50 ml stock potassium
nitrate solution to 500 ml with distilled water; 1.00 ml = 10.0 yg N = 44.3
yg N03." (Standard Methods, 13th Ed., 1971, p. 456).
81
-------
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2.0
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100 % Recovery
Extrapolated Cone., mg/J
Measured With
Standard Addition
1:25 Dilution
16 7o Recovery
.5
1,0
0.5
0
0.5
1,0
1,5
Added Concentration NO,-N, mg/J?
O
1:50
Dilution
118%
Recovery
2.0
2.5
Figure 27. The Nitrate Determination with the Nitrate Electrode
Using Standard Additions
82
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1.0
0.5
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I', 25 Dilution
(80 7o Recovery)-
. Extrapolated
Concentration
mg/l
Measured With
Standard Addition
OJ
CO
1150 Dilution
(59 7o Recovery)
-100% Recovery
1.0
0.5
0
0.5
Added Concentration
1.0
-N, mg/P
1.5
2.0
Figure 29. The Nitrate Determination with the Brucine
Sulfanilic Acid Method Using Standard Additions
84
-------
Procedures for the Nitrate Electrode Method
Calibrate the electrode system against standard solutions of increas-
ing concentrations, as shown in Figure 28, using the nitrate electrode
connected with a pH meter. Because of the different makes of nitrate
electrodes which are available commercially, it fs not possible to pro-
vide detailed instructions for the correct operation of each electrode.
In each case therefore follow the manufacturer's instructions.
Determine the potential in the sample to be measured and convert
this into a nitrate concentration using the calibration curve. When
making standard additions, add increasing amounts of standard solution
to the sample and dilute to a specified volume. Measure the concentra-
tions and construct a graph as shown in Figure 27. Extrapolation of the
obtained values enables the calculation of the initial nitrate concen-
tration.
8.6 THE NITRITE DETERMINATION
Principle
Nitrite is an intermediate nitrogen form when ammonia is converted
to nitrate. Nitrite is generally present in lower concentrations than
nitrate and its determination is only useful when the nitrates are deter-
mined concurrently.
The only method that is mentioned in Standard Methods for the deter-
mination of nitrite is the naphthylamine method.A reddish purple azo
dye is formed at pH 2.0 by the coupling of diazotized sulfanilic acid
with naphtylamine hydrochloride. The reaction is to some extent similar
to the brucine method to determine nitrate which gives a yellow color
as the result of the reaction of nitrate sulfanilic acid and brucine.
The EPA (1971) recommends the use of the less cancinogenic n-(l-napthyl)-
ethylenediamine instead of the naphylamine.
Interference
A precipitate of the colored complex can be caused by the presence
of ferric iron and lead, while cupric ions may cause a lower reading.
Interference of other ions may be reduced by EDTA addition (EPA, 1974).
Colored ions will likewise interfere.
Previous Studies
Several studies that determine nitrates do not analyze for nitrites.
None of the studies that include the parameter in their measurements
recommend it as an accurate method. Automated analysis (Technicon, 1973)
also uses the reaction between nitrite, sulfanilamide and naphtylamine.
85
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Evaluation of the Method
When the test was run on an unfiltered leachate sample with standard
additons of nitrite, a high nitrite concentration of 4.8 mg/£ was obtained
while the recovery was relatively low (Figure 30). The recovery in the
1:25 dilution was 66 percent which decreased to 26.7 percent for the 1:50
dilution. Since the color of the sample was deep purple rather than pink
as observed for the standards, it was suspected that a precipitate had
formed. Filtration of the 1:25 diluted leachate after the color had formed
caused a 60 percent decrease in absorbance while the recovery decreased
from 66 percent to 39.5 percent, suggesting that the solids in the sample
enhanced the absorbance. This is confirmed by the lower recovery in the
1:50 dilution (26.7 percent) as compared to the 1:25 dilution (66 percent),
since increasing dilutions enhance the oxidation of the ferrous iron and
the formation of suspended solids consisting of iron hydroxide. A second
run was therefore made in which the leachate sample was filtered twice
through a Whatman #1 filter paper prior to running the analysis. The
results showed that filtration before color development caused an even
further decrease in nitrite recoveries since the recovery of the 1:25
dilution decreased from 66 percent to 7.1 percent and that of the 1:50
dilution from 26.7 percent to 8.8 percent, while the extrapolated concen-
tration decreased from 4.8 mg/£ to 0.8 mg/£. However, at a nitrite concen-
tration of 0.030 mg/l the recovery of the 1:50 dilution showed a sharp
increase approaching 100 percent. The 1:25 dilution gave this increase
at a concentration of approximately 0.050 mg/£. This pattern may indicate
that the sample has a nitrite demand that has to be satisfied before any
free nitrite will be present in the sample. This observation was con-
firmed in a third run in which relatively high concentrations of nitrite
were added to the filtered sample and whereby the 1:25 diluted leachate
sample had a recovery of 70 percent and the 1:50 diluted sample a recovery
of 93 percent, while both curves showed that the sample had a nitrite
demand.
The above results indicate that nitrite is likely to be absent in a
polluted leachate sample obtained from a fill recently generating leachate
but may be present in biologically stabilized leachate. Alleged nitrite
concentrations measured are sometimes due to interferences present in the
sample.
Recommendations
It is recommended that nitrite be determined according to Standard
Methods with additions of standard amounts of Nitrite-N to the fi1tered
sample. Extreme care should be exercised in interpreting the obtained
results. The napth.ylamine reagent should be replaced by the n-(l-napthyl)
ethylene diamine.
86
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87
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Reagents for the Naphthyl ethylenediamine Method
"EDTA solution: Dissolve 500 mg disodium ethylenediamine tetra-
acetate dihydrate in nitrite-free water and dilute to 100 mi.
Sulfanilic acid reagent: Completely dissolve 600 mg sulfanilic acid
in 70 m hot distilled water, cool, add 20 mi cone. HC1 , dilute to 100 mi
with distilled water, and mix thoroughly.
Naphthyl ethylenediamine dihydrochloride reagent: Dissolve 800 mg of n-
(1-napthyl) ethylenediamine dihydrochloride in distilled water to which
1.0 ml cone. HC1 has been added. Dilute to 100 mi with distilled water
and mix thoroughly.
Sodium acetate buffer solution, 2 M: Dissolve 16.4 g NaC2HQ02 or
27.2 g NaC2H302 • 3H20 in nitrite- free water and dilute to 100 mi. Filter
if necessary.
Stock nitrite solution: The reagent grade of sodium nitrite avail-
able commercially assays at less than 99 percent. Since nitrite is
readily oxidized in the presence of moisture, fresh bottles of reagent
are desirable for the preparation of the stock solution. The preferred
approach is to determine the sodium nitrite content immediately before
preparation of the stock solution and to keep bottles tightly stoppered
against the free access of air when not in use. The sodium nitrite con-
tent may be determined by adding an excess of standard potassium perman-
ganate solution, discharging the permanganate color with a standard
reductant such as sodium oxalate or ferrous ammonium sulfate solution,
and finally back-titrating with standard permanganate solution.
Preparation of Stock Solution: Dissolve 1.232 g sodium nitrite,
NaNO?, in nitrite- free water and dilute to 1 ,000 m€f 1 .00 mi = 250yg
N. Preserve with 1 mi chloroform.
Standard nitrite solution: Dilute 10.00 m intermediate nitrite
solution to 1,000 mi with nitrite-free water; 1.00 mi = 0.500 yg N.
Prepare daily.
Calcium hydroxide suspension: Prepare a 1 percent stock solution
by dissolving 10 g CaO in 1 i distilled water." (Standard Methods, 13th
Ed., 1971, p. 241).
Procedure for the Naphthyl ami ne Method
Suspended solids are only partially removed by filtration, while
better removal is obtained at a massive lime dosage of 5000 to 10,000
mg/i Ca(OH)2.
88
-------
"Color Development: To 50.Q mi clear sample which has been neutra-
lized to pH 7, or to an aliquot diluted to 50.0 mi, add 1.0 mi EDTA solu-
tion and l.Q mi sulfanilic acid reagent. Mix thoroughly. At this point,
the pH of the solution should be about 1.4. After the reaction has pro-
ceeded for 3 to 10 min, add l.Q mi naphthylamine hydrochloride
reagent and 1.0 mi sodium acetate buffer solution; mix well.
At this point, the pH of the solution should be 2.0. Measure the
reddish purple color after 10 to 30 min. Measure the absorbance at or
near 520 nm against a reagent blank and run parallel checks frequently
against known nitrite standards, preferably in the nitrogen range of the
samples.
mg/£ nitrite N = ^ ;1tr1t.e N
d mi sample
(Standard Methods, 13th Ed., 1971, p. 242-243).
8.7 THE AMMONIA DETERMINATION
Principle
Ammonia is present in relatively high concentrations in young leach-
ate due to the degradation of the organic nitrogen compounds. In more
stabilized leachate it is present at lower concentrations since a signifi-
cant portion has been converted to nitrates.
The oldest method to determine ammonia concentrations is the Nessler-
ization Method in which mercuric iodide and potassium iodide react with
ammonia to give a yellow to brown color. Since this is identical to the
color of the leachate, interferences may be encountered. Precipitates of
calcium bicarbonate and ferric hydroxide also strongly interfere as do
organic compounds such as aldehydes which makes the method less applicable
to leachate analysis.
The phenate method as listed in Standard Methods to determine ammonia
is based on the intense blue colored indophenol complex formed by the reac-
tion of the ammonia hypochlorite and phenol catalyzed by a manganous salt,
but color and turbidity, as are generally present in leachate, interfere
with the analysis (APHA, 1971). The EPA (1974) automated procedure also
uses the color reaction of ammonia with alkaline phenol hypochlorite to
form the blue-green indophenol color (Berthelot Reaction). The inter-
ference by high concentrations of Ca and Mg may be partially reduced by
the addition of EDTA or Rochelle salt. The presence of iron and chromium
tends to enhance the color. The test is also markedly interfered with
by the buffering capacity of leachate as a result of the high acidity.
As the color of the reaction product is pH dependent, the standard used
to calibrate the autoanalyzer should therefore have the same pH as the
sample.
89
-------
The most applicable method for leachate analysis consists of distil-
lation of the ammonia in a phosphate buffer at pH 7.4 and collecting the
distillate in boric acid. The ammonia can then be determined colorimet-
rically with the Nessler reagent wnen low concentrations are present, or
by titration with a standard solution of strong acid at higher ammonia
concentrations.
The selective ion electrode method as recommended by EPA (1974) is
also free of many interferences mentioned above for the other methods.
Interferences
The largest difficulty in the distillation step is maintaining the
pH of 7.4. When the pH of the distillation mixture is too high, certain
organic nitrogen compounds are converted to ammonia thus increasing the
apparent concentration, and when the pH is too low, the recovery of ammonia
is too low. A relatively large amount of Ca will decrease the pH since
calcium and the phosphate buffer reacts to precipitate calcium phosphate,
releasing hydrogen ions, and thus reducing the pH.
Previous Studies
The interferences in the direct Nesslerization were recognized by
Foree and Cook (1972) who therefore used the distillation step prior to
the Nesslerization. Foaming may sometimes pose a problem in the distil-
lation step. The EPA (1974) recommends distillation in borate buffer
at a pH of 9.5 as opposed to 7.4 in Standard Methods. The former method
was used by the State Water Quality Control Board of California (Appendix
A). The automated indophenol method was used by Pohland and the Depart-
ment of Environmental Resources of Pennsylvania (Appendix A). Since
relatively little interference was reported for both the specific ion
electrode and the Kjeldahl distillation, both were evaluated.
Evaluation of Method
The ammonia concentration was tested with both the electrode and
the distillation method. A calibration curve was made for the electrode
with NlfyCl as a standard (Figure 31) whereafter the samples were run at
a 1:10 and 1:50 dilution with standard amounts of NF^Cl added to the
sample. The potentiometric method generally gave good results. Figure
32 shows that the extrapolated values at the 1:10 and 1:50 dilution are
570 mg/£ and 600 mg/£ respectively which is within 97 percent of each
other. The 1:10 dilution gave a 113 percent recovery, slightly more
than 100 percent, indicating that there are substances present in leachate
that enhance the reading of the electrode. Samples should therefore
be run at a sufficiently large dilution to eliminate this.
90
-------
500
100
50
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Potential, mV
Figure 31. Calibration Curve for the Ammonia Electrode
91
-------
400
300
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200
100
— 100 % Recovery
HO Dilution
M37o Recovery
Extrapolated
Concentration, mg A
Measured With
Standard Addition
E
O
00
in
it
O
x
00
in
1=50 Dilution
100% Recovery
I
100 50 0 50 100
Added Concentration,
150
200 250
Figure 32. The Ammonia Determination with the Potentiometric
Method Using Standard Additions
92
-------
The distillation procedure gave similar results as the electrode
for the 1:50 dilution i.e. 600 mg/l with an almost 100 percent recovery
at concentration below 75 mg/l (Figure 33). The 1:10 dilution, however,
gave a result of 720, mg/l which is 20 percent higher than observed for
th.e 1:50 dilution while the recovery was only 86 percent. Since this
is an unsatisfactory response of the test, a further evaluation was made.
A study of the literature showed that in order to obtain good ammonia
recovery, the pH of the distillate should remain above 7.1 during the
entire distillation. The pH is maintained at this level by addition of
10 ml buffer or 10 ml more for each 250 mg/£ Ca in tFie sample. In the
1:10 dilution this represents 10 + 10 = 20 ml and 15 ml for the 1:50
dilution. Measurement of the pH before and after distillation showed
that the recommended amount of buffer could not maintain the pH at the
desired level. The result of the pH decrease on the recovery of Nhfy -N
in the 1:50 dilution is shown in Figure 34. These data indicate that a
decreasing pH causes a decreasing recovery of the ammonia. Figure 34
also shows that the pH decrease is dependent on the dilution of the
leachate and is less significant at smaller dilutions possibly corres-
ponding with higher buffer concentrations. However, when the final pH
of the'distillate becomes larger than 7.1 in the 1:50 dilution of 7.2 in
the 1:10 dilution, the recovery exceeds 100 percent indicating that at
higher pH nitrogeneous compounds are converted to ammonia and also dis-
tilled off. Further evaluation of the data shown in Figure 34 also
indicated that increasing ammonia concentrations correspond to a
decreasing pH. This then explains why the recovery of the ammonia in
the 1:50 diluted leachate sample approaches 100 percent at low values
but becomes less than 100 at increasing concentrations. Thus the ammonia
concentration in the 500 ml sample should not exceed 75 mg/l unless
additional buffer is added. The results clearly show that the sample
should not be distilled at pH 9.5 as recommended by EPA (1974) as
nitrogeneous compounds will be hydrolyzed at that pH.
Recommendations
It is recommended that ammonia concentrations be determined with
either the specific ion electrode after sufficient dilution to reduce
matrix interference of the leachate, or with the distillation method when
the concentration in the diluted sample does not exceed 75 mg/l unless
additional buffer is added to the leachate sample. A pH maintained at
7.4 is sufficiently high to distill off the ammonia. A pH of 9.4 as
recommended by EPA (1974) is too high, causing partial destruction of
the organic nitrogen.
Reagents for Ammonia Distillation and Titration Method
"Ammonia-free water: Prepare by ion-exchange or distillation methods,
Since it is virtually impossible to store ammonia-free water in the lab-
93
-------
400
300 —
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100% Recovery
10 Dilution
Extrapolated
Concentration, mg/JP
Measured With
Standard Addition
200
50 0 50 100
Added Concentration ,
150 200
Figure 33. The Ammonia Determination with the Distillation Method
Using Standard Additions
94
-------
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no
100
90
— I!50 Dilution
6,5
7,0
pH(-)
Initial pH
7,5
Figure 34. Effect of Final pH of Distillate on Recovery of
Ammonia during the Kjeldahl Distillation
95
-------
oratory without contamination from ammonia fumes, for best results pre-
pare fresh for each batch of samples.
Phosphate buffer solution pH 7.4: Dissolve 14.3 g potassium
dihydrogen phosphate, KH2P04, and 68.8 g dipotassium hydrogen phosphate,
K^HPO*, then dilute to 1 I with ammonia-free water. Determine the ammonia
nitrogen blank on the buffer solution." (Standard Methods, 13th Ed.,
1971, p. 225).
"Mixed indicatory solution: Dissolve 200 mg methyl red indicator in
100 m£ 95 percent ethyl or isopropyl alcohol. Dissolve 100 mg methylene
blue in 50 ma 95 percent ethyl or isopropyl alcohol. Combine the two
solutions. Prepare monthly.
Indicating boric acid solution: Dissolve 20 g HsB03 in ammonia-free
distilled water, add 10 ml mixed indicator solution, and dilute to 1 t.
Prepare monthly.
Standard sulfuric acid titrant, 0.02 N: Prepare and standardize as
directed in Alkalinity, Section 8.4.For greatest accuracy, standardize
the titrant against an amount of sodium carbonate which has been incor-
porated in the indicating boric acid solution to reproduce the actual
conditions of the sample titration. A standard acid solution, exactly
0.0200 N, is equivalent to 280 yg N per 1.00 mt." (Standard Methods,
13th Ed., 1971, p. 245).
Procedures for Ammonia Distillation and Titration Method
"Sample preparation: Use a 500 mi sample or an aliquot diluted to
500 ml with ammonia-free water in order to obtain an ammonia concentra-
tion less than 75 mg/l. If necessary, neutralize the sample to approx-
imately pH 7 with the dilute acid or base, using a pH meter. Add 10 ml
phosphate buffer solution. For most water samples this volume is
sufficient to maintain a pH of 7.4 ± 0.2 during distillation. For samples
containing more than 250 mg Ca, add an additional 10 ml buffer solution
for each 250 mg Ca in the sample and adjust to pH 7.4 with acid or base.
Carry out the following steps without any intervening delay:
Preparation of equipment: Add 500 ml distilled water, 10 ml phos-
phate buffer solution, and a few glass beads or boiling chips to a flask
of appropriate capacity; steam out the entire distillation apparatus
until the distillate shows no trace of ammonia.
Distillation: In order to minimize contamination, leave the entire
distillation apparatus assembled after the steaming-out process until
just before the actual sample distillation is to be started. Empty the
distilling flask, taking care to leave the glass beads or boiling chips
96
-------
in it. Pour in the neutralized and buffered sample. Distill at a rate
of 6-10 m£/min with the tip of the delivery tube submerged, collecting
the distillate in a 500-m£ erlenmeyer flask containing 50 mi boric acid
absorbent. Use additional 50-m£ increments of boric acid for each mg of
ammonia nitrogen distilled. Collect at least 300 ml distillate. Lower
the collected distillate, free of contact with the delivery tube, and
continue distillation during the last minute or two to cleanse the con-
denser and delivery tube. Dilute to 500 mi with ammonia-free water.
Titrate the ammonia in the distillate with standard 0.02 N sulfuric
acid titrant until the indicator turns a pale lavender.
Blank: Carry a blank through all the steps of the procedure and
apply the necessary correction to the results.
where D = mi H2S04 titration for sample and E = mi ^$04 titration for
blank." (Standard Methods. 13th Ed., 1971, pp. 246-247).
8.8 THE SODIUM AND POTASSIUM DETERMINATION
Principle
Sodium (Na) and potassium (K) are present in high concentrations
in leachate collected from a recently generating fill and retains rela-
tively high concentrations with respect to the other cations during stab-
ilization of the fill. Passage through soil may reduce the sodium and
potassium concentration by exchange against calcium and magnesium.
The most rapid and sensitive method uses flame emission photometry
to determine sodium and potassium concentrations at a wavelength of
5890 A and 7665 A\ The sample is sprayed into a gas flame and excita-
tion is carried out under carefully controlled conditions after which the
intensity of light is measured by a potentiometric photometer.
Interferences
Parti cul ate matter can cause burner clogging and should be removed
by filtration through a medium pore sized filter paper (APHA, 1971).
Potassium and calcium have been reported to interfere with the sodium
determination if the potassium to sodium ratio is equal or larger than 5:1,
or when the calcium to sodium ratio is equal to larger than 10:1. Among the
97
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common anions causing radiation interference are phosphates,chlorides,
sulfates and bicarbonates, respectively,in relatively large amounts.
Indirect interferences are caused by changes in temperature and
composition of the flame which results in a shift of equilibrium between
gaseous atoms, ions or molecules. A low temperature flame is therefore
recommended for sodium and potassium as it reduces the ionization of the
atom. Recommended flames are the propane-air flame which has a temperature
of approximately 1900° C, while higher temperatures of approximately 2400°
C are obtained with an acetylene-air flame (Rich, 1965).
Previous Studies
Most studies used flame emission photometry to determine Na and K
concentration, and applied the method without modification. One study
calculated Na and K concentrations from the hardness and total solid
determinations. Only one study added Cs to the sample to suppress the
ionization of the analytical ion.
Standard Methods recommends both the use of direct reading
flame photometers, in which the light of the selected wavelength causes a
current, and internal standard flame photometers, in which one cell intercepts
the radiation emitted by the internal standard Li while the other cell
intercepts the radiation of the element to be determined. The latter system
is subject to fewer interferences then the former.
The EPA (1974) n commends atomic" ab§orption spectroscopy to determine
sodium and potassium at 3302 A and 7665 A, respectively, while t^e USGS
(Brown ert a\_., 1973) recommends a wavelength of 5888 A and 7665 A for sodium
and potassium, respectively. For more sensitive determinations, EPA (1974)
recommends a wavelength of 5890 A for the sodium determination; a similar
recommendation was made by Parker (1972). The EPA (1974) does not recommend
any additions for the sodium and potassium determination, while Parker
(1972) recommends a 1000 mg/1 cesium nitrate addition for the sodium and
potassium determination to suppress the ionization of the analyte ion,
especially when using an air acetylene flame.
Evaluation of the Method
An extensive evaluation of the method showed the necessity to add the
easily ionizable ion Cs to the sample at a concentration of 1000 mg/1 in the
final dilution to suppress the ionization of the analytic ion.
Recommendations
It is recommended that Na and K be determined by flame photometry and
that Cs is added to the sample to suppress the ionization of the analyte
ion in the flame,when the determination is made by atomic absorption spectroscopy.
98
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Reagents for the Sodium Determination
Deionized distilled water: Use deionized distilled water for the
preparation of all reagents, calibration standards, and as dilution water.
Stock sodium solution: Dissolve 2.542 g NaCl dried at 140° C and
dilute to 1,000 mi with deionized distilled water to form a solution
containing 1.00 mg Na per 1.00 mi.
Intermediate sodium solution: Dilute 10.00 mi stock solution with
deionized distilled water to 100.0 mi to form a solution containing 100
yg Na per 1.00 mi. Use this intermediate solution for preparing the
calibration curve in the sodium range of 1-10 mg/l." (Standard Methods,
13th Ed., 1971, p. 318). Store all solutions in polyethylene bottles.
Prepare a CsNOs stock solution: Dissolve 14.7 g dried at 104° C
and dilute to 100 m£ with deionized distilled water to form a solution
containing 10,000 mg/£ Cs.
Procedure for the Sodium Determination
Pipet 10 mi of the Cs stock solution and add to 50 mi of filtered
sample, dilute to 100 mi.
Instrument operation: Because the differences between the makes and
models of satisfactory flame photometers render impossible the formula-
tion of detailed instructions applicable to every instrument, follow the
manufacturer's recommendation for the selection of the proper photocell
and wavelength, the adjustment of the slit width and sensitivity, the
appropriate fuel and air or oxygen pressures, and the steps for warm-up,
correcting for flame background, rinsing of the burner, ignition of
sample, and measurement of emission intensity. Because of the relative
high concentrations of sodium in leachate a wavelength of 3302 A will be
sufficient for the desired accuracy.
Reagents for the Potassium Determination
"Deionized distilled water: Use this water for the preparation of
all reagents, calibration standards, and as dilution water.
Stock potassium solution: Dissolve 1.907 g potassium chloride, KC1
dried at 110° C and dilute to 1,000 mi with deionized distilled water to
form a solution containing 1.00 mg K/l.00 mi.
Intermediate potassium solution: Dilute 10.00 m£ stock potassium
solution with deionized distilled water to 100 mi to make a solution
containing 100 yg K/l.00 mi. Use this solution for preparing the cali-
bration curve in the potassium range of 1-10 mg/t." Store all solutions
in polyethylene bottles.
99
-------
Prepare a CsN03 stock solution Dissolve 14.7 g dried at 104° C and
dilute to 1000 mi with deionized distilled water to form a solution con-
taining 10,000 mg/t Cs." (Standard Methods, 13th Ed., 1971, p. 284).
Procedure for the Potassium Determination
Pipet 10 mi of the Cs stock solution and add to 50 m£ of filtered
sample, dilute to 100 ml.
"Instrument operation: Because the differences between the makes
and models of satisfactory flame photometers render impossible the for-
mulation of detailed instructions applicable to every instrument, follow
the manufacturer's recommendation for the selection of the proper photo-
cell and wavelength, the adjustment of the slit width and sensitivity,
the appropriate fuel and air or oxygen pressures, and the steps for warm-
up, correcting for flame background, rinsing of the burner, ignition gf
sample, and measurement of emission intensity. A wavelength of 7665 A
is recommended for most measurements but may be changed to 4044 A when
very high concentrations are present." (Standard Methods, 13th Ed., 1971,
p. 319). r-
8.9 THE Ca AND Mg DETERMINATION
Principle
Calcium (Ca) can be determined gravimetrically as calcium oxalate,
with the permanganate titrimetric method, the EDTA titrimetric method or
by atomic absorption spectroscopy. The gravimetric method which measures
the precipitate of calcium oxalate at alkaline pH is interfered by iron,
phosphate and suspended matter, all present in leachate since these sub-
stances are also removed by filtration. In the permanganate titrimetric
method the precipitated calcium oxalate is redissolved in acid and titrated
with permanganate which oxidizes the oxalate. This method is therefore
subject to the same interferences as the gravimetric method. In the EDTA
titrimetric method the magnesium (Mg) is first precipitated at high pH
after which EDTA is added to combine with the Ca. A color indicator is
used to indicate the endpoint of the titration when all Ca is complexed.
The method is subjected to numerous interferences and 20 mg/l of both
ferrous and ferric iron interfere, as do 5 mg/£ zinc, 5 mg/£ lead,
2 mg/l copper while an alkalinity above 20 mg/l causes an indistinct
endpoint. Due to the limitations of the previous methods, the EPA (1974)
recommends atomic absorption spectroscopy as the most accurate measure-
ment subject to least interferences.
Magnesium can be determined by the gravimetric method only after
prior removal of Ca and is generally determined in the filtrate of the
Ca gravimetric method. In the gravimetric Mg method diammonium hydrogen
100
-------
phosphate precipitates Mg as magnesium ammonium phosphate in an ammoniacal
solution. Iron and suspended matter however interfere. Magnesium can
also be determined with the photometric method in which magnesium hydroxide
is precipitated in the presence of brilliant yellow. Chlorides at 250
mg/£, iron at 2.5 mg/£ and any zinc, however, interfere, making the method
less suitable for leachate analysis. For that reason the EPA (1974)
recommends the atomic absorption method.
Interferences
Phosphate and sulfate interferes in the atomic absorption calcium
determination and 200 mg/£ of each caused a 35 percent and a 30 percent
depression, respectively (Parker, 1972). Both effects are masked by the
addition of Lanthanum chloride. Concentrations of more than 1000 mg/£
magnesium and 500 mg/£ each of sodium and potassium cause a 5-10 percent
enhancement due to suppression of the calcium ionization (Brown et aj_. »
1970). The magnesium determination is interfered with by more than
400 mg/£ each of sodium, potassium and calcium, while phosphates and
sul fates also cause interferences. Silicates and carbonates at 200 mg/£
each caused a 42 percent and 17 percent depression respectively (Parker,
1972). Phosphate for example will bind the magnesium and prevent the
magnesium atomic absorption when the light passes through the flame.
Interferences in the calcium and magnesium determinations are reduced
by addition of an inorganic "releasing" agent La to the sample which
prevents the binding of Ca and Mg by anions. The interferences are also
reduced by using a nitrous oxide-acetylene flame, instead of the lower
temperature air-acetylene flame.
Previous Studies
Most of the early studies measuring calcium and magnesium in leachate
use colorimetric analysis, but later studies generally use EDTA titra-
tion. Only recent studies, however, use atomic absorption spectroscopy.
In most of these studies, La is added as a releasing agent to the sample.
o
The Standard Methods recommend a wavelength of 2852 A for the mag-
nesium determinations. Brown et al . (1970) uses 4227 § for calcium and
~
2852 A for magnesium. The EPA~Tl974) recommends 4227 A for most calcium
measurements, 2399 A only for very high calcium concentrations and 2852
A" for magnesium. The EPA (1974) recommends a final concentration of
4500 mg/£ La while all other studies recommend 10,000 mg/l in the final
dilution.
Evaluation of Method
Evaluation showed that only 90 percent of the added Ca is recovered
from leachate samples but that approximately 100 percent was recovered in
101
-------
the presence of La. The Mg recovery in the presence of La did not differ
greatly from the recovery in the absence of La.
Recommendations
It is recommended that Ca and Mg be determined with atomic absorp-
tion spectroscopy using 10,000 mg/£ La to reduce interferences.
Reagents for the Calcium Determination
"Stock lanthanum reagent: Dissolve 58.65 g lanthanum oxide,
in 250 mi cone. HC1. Dilute to 1,000 mi with distilled water to obtain
a solution containing 5 g La/100 mi. Add the acid slowly until the
material is dissolved. Add sufficient amounts of this solution to the
standards and unknowns in order to obtain a final working concentratin
of 1 g La/100 mi volume."
Stock calcium solution: Suspend 1,250 g CaCOs, analytical reagent
grade, dried at 180° C for 1 hour before weighing in deionized distilled
water and dissolve cautiously with a minimum of dilute HC1, dilute to
1,000 mi with deionized distilled water; 1 mi =0.5 mg/i or 500 mg/£.
Prepare dilutions of the stock calcium solutions to be used as
calibration standards. To each standard add 2 mi La stock solution and
dilute till 10 mi.
Procedures for Calcium Determination
When high concentrations of suspended solids are present, the sample
will have to be digested according to 8.11, otherwise the Ca can be
determined directly.
"Because the differences between makes and models of satisfactory
atomic absorption spectrophotometers render impossible the formulation
of detailed instructions applicable to every instrument, follow the
manufacturer's operating instructions. As a rule, choose the correct
hollow cathode lamp, install, and align in the instrument; position the
monochromator at the correct wavelength indicated by EPA (1974); select
the proper monochromator slit width; set the light source current accord-
ing to the manufacturer's recommendation; light the flame and regulate
the flow of fuel and oxidant; adjust the burner for maximum absorption
and stability; and balance the photometer. Then run the standards needed
for the working curves and plot the concentrations of the standards against
absorbance. If necessary on some instruments, convert percentage absorp-
tion to absorbance (the calibration curves are nearly linear for most
elements). Next, run the samples and read the concentration of each sample
102
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from the calibration curve. Overcome instrumental drift by conducting
the absorbance measurements of blank, calibration standards, and samples
frequently and without undue delay. Record multiple readings (three
or more) for averaging." Some of the recommended instrumental parameters
are: measurement with the Ca hollow cathode lamp at 4227 A; use of air-
acetylene fuel and a reducing type flame." (Standard Methods, 13th Ed.,
1971, p. 213).
Reagents for the Magnesium Determination
"Stock lanthanum reagent: Dissolve 58.65 g lanthanum oxide, 13203,
in 250 ml cone. HC1. Dilute to 1,000 m£ with distilled water to obtain a
solution containing 5 g La/100 mi. Add the acid slowly until the material
is dissolved. Add sufficient amounts of this solution to the magnesium
standards and unknowns in order to obtain a final working concentration
of 1 g La/100 mi volume." (Standard Methods, 13th Ed., 1971, p. 212-213).
Stock magnesium solution: Dissolve 0.829 g of magnesium oxide, MgO
in 10 mi of redistilled HNOs and dilute to 1 I with deionized distilled
water; 1 ml = 0.50 mg Mg, 500 mg/£.
Procedures for Magnesium Determination
Prepare dilutions of the stock calcium solution to be used as cali-
bration standards. To each standard add 2 mi La stock solution and dilute
till 10 me.
Because the differences between makes and models of satisfactory
atomic absorption spectrophotometers render impossible the formulation
of detailed instructions applicable to every instrument, follow the
manufacturer's operating instructions. As a rule, choose the correct
hollow cathode lamp, install, and align in the instrument; position
the monochromator at the correct wavelength indicated by EPA (1974);
select the proper monochromator slit width; set the light source current
according to the manufacturer's recommendation; light the flame and
regulate the flow of fuel and oxidant; adjust the burner for maximum
absorption and stability; and balance the photometer. Then run the
standards needed for the working curves and plot the concentrations of
the standards against absorbance. If necessary on some instruments,
convert percentage absorption to absorbance (the calibration curves
are nearly linear for most elements). Next, run the samples and read
the concentration of each sample from the calibration curve. Overcome
instrumental drift by conducting the absorbance measurements of blank,
calibration standards, and samples frequently and without undue delay.
Record multiple readings (three or more) for averaging. Some of the
recommended instrumental parameters are: measurement with the Mg
hollow cathode lamp at 2852 A; use of air-acetylene fuel and a reducing
type flame.
103
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8.10 HARDNESS DETERMINATION
Principle
The hardness reflects the total concentration of polyvalent metals
mainly calcium and magnesium but will include iron, zinc and copper when
present in significant quantities. The most accurate method is by
summation of the individual polyvalent metals as measured by atomic
absorption spectroscopy which are then expressed as CaC03 equivalents.
A more rapid method is based on EDTA titration of the sample. Addi-
tion of Eriochrome Black T (EBT) results in wine red color as a result of
the interaction with Ca and Mg. Titration with EDTA will complex these
metals after which the EBT color changes from wine red to blue. The EPA
(1974) recommends calmagite as an indicator instead of EBT, which causes
a color change from red to blue during the titration. The automated
EPA (1974) method is based on the exchange of Mg in Mg-EDTA for other
polyvalent cations, followed by colorimetric determination of Mg by
calmagite to give a red complex.
Interferences
Fading of the endpoint is caused by the interference of some heavy
metals which can be reduced by addition of complexing agent such as NaCN
(extremely toxic). However, even after addition of the NaCN, iron, copper
or zinc at a concentration above 10 mg/£ will interfere and contribute
to the hardness (Brown, e_t ^]_., 1970). The EDTA methods as recommended
by EPA (1974) are therefore subject to similar interferences. Suspended
solids and organic matter will also interfere with the determination as
they influence the chelation of the cations by EDTA, but can be removed
by drying and ignition at 550° C.
Previous Studies
Most studies use the EDTA titration for the hardness determination.
Some of the studies add NaCN to the sample to reduce interferences from
other metals. Only a few studies determine the hardness by calculation
from the concentraiton of the individual components.
Evaluation of the Method
Hughes et_ aj_. (1971) stated that the values for hardness as calcu-
lated from the analysis of the individual ions did not compare with the
values obtained from the EDTA titration. Difficulty encountered in
observing the exact endpoint of the titration was due to the presence of
colored suspended matter. The County of Sonoma, Emcon Associates (1973)
also noted that addition of NaCN did not reduce all interferences.
104
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Recommendations
It is recommended that the hardness be calculated from the concen-
tration of the individual polyvalent metals as determined with atomic
absorption spectroscopy and should include Ca, Mg, Fe, Al, Zn, Cu and
other polyvalent cations.
8.11 DETERMINATION OF HEAVY METALS
Principle
Although several colorimetric methods are available for heavy metal
determinations all are subject to strong interferences. For that reason
EPA (1974) recommends atomic absorption for the determination of most
el ements.
Interferences
Several interferences are reported for the atomic absorption deter-
mination and can be classified as chemical, non-atomic, ionization and
spectral (EPA, 1974). Chemical absorption occurs when heavy metals are
not available in the atomic form because of molecular combination with
anions present in the solution. This interference can sometimes be over-
come by addition of a releasing agent such as Cs. The presence of a high
concentration of dissolved solids may cause a non-atomic interference such
as by light scattering. This effect is partially corrected by measuring
absorbance of a nearby non-adsorbing wavelength. Ionization interferences
occur when the atom ionizes in the flame after which it is not available
for atomic absorption. This interference is reduced by addition of an
easily ionized element such as Cs to suppress the ionization of the
analyte atom. Spectral interference can occur when the absorbing wave-
length of another element falls within the width of the absorption line
of the analyte atom. Such interference is partially reduced by narrowing
the slit width of instrument.
Previous Studies
The first studies analyzing leachate use colorimetric analysis but
later studies generally use atomic absorption methods. Some of these
studies, however, continue to measure iron with colorimetric methods. One
study removed turbidity from the sample by centrifugation (Fungaroli,
1971) but this may have reduced the heavy metal content in the sample
since several metals are adsorbed onto the ferric hydroxide particles.
The turbidity interference is best reduced by acid digestion as recommended
by EPA (1974). None of the studies use the standard addition method to
evaluate the recovery of the determination.
105
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Evaluation of the Method
An extensive study was made of the interferences of the atomic
absorption method in leachate analysis and interferences were found to
reduce the recovery by as much as 44 percent. The interferences were
especially large for the elements Pb, Cu, Ni and Cr and smaller for Zn
and Cd and was best noticeable in high strength leachate, but decreased
in magnitude for more stabilized leachate. The broad non specific
molecular absorption and light scattering is measured at a bordering
wavelength or at the same wavelength as the analyte ion using an
hydrogen lamp.
Recommendations
It is recommended that the heavy metals be determined with atomic
absorption techniques and that standard additions are used for leachates
of high strength to determine the magnitude of the interference. The
standard additions should be used for the elements lead, copper, nickel
and chromium, but may be omitted for Zn and Cd. For total metal
analysis the sample should be collected in a polyethylene bottle and
acidified to pH 2 with 1:1 redistilled nitric acid, linen the dissolved
metals, i.e. filterable through 0.45 y are determined, the suspended
metals should be determined concurrently.
Procedures for Total Metal Analysis
"Transfer a representative aliquot of the well mixed sample to a
Griffin beaker and add 3 mi of cone, redistilled HN03. Place the beaker
on a hot plate and evaporate to dryness cautiously, making certain that
the sample does not boil. Cool the beaker and add another 3 mt portion
of cone, redistilled HN03. Cover the beaker with a watch glass and
return to the hot plate. Increase the temperature of the hot plate so
that a gentle reflux action occurs. Continue heating, adding additional
acid as necessary, until the digestion is complete (generally indicated
by a light colored residue). Add sufficient distilled 1:1 HC1 and again
warm the beaker to dissolve the residue. Wash down the beaker walls
and watch glass with distilled water and filter the sample to remove
silicates and other insoluble material that could clog the atomizer.
Adjust the volume to some predetermined value based on the expected
metal concentrations. The sample is now ready for analysis." (EPA,
1974, p. 83).
"Because the differences between makes and models of satisfactory
atomic absorption spectrophotometers render impossible the formulation
of detailed instructions applicable to every instrument, follow the
manufacturer's operating instructions. As a rule, choose the correct
hollow cathode lamp, install, and align in the instrument; position the
106
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monochromator at the correct wavelength indicated by EPA (1974); select
the proper monochromator slit width; set the light source current accord-
ing to the manufacturer's recommendation; light the flame and regulate
the flow of fuel and oxidant; adjust the burner for maximum absorption
and stability; and balance the photometer. Then run the standards
needed for the working curves and plot the concentrations of the standards
against absorbance. If necessary on some instruments, convert percentage
absorption to absorbance (the calibration curves are nearly linear for
most elements). Next, run the samples and read the concentration of each
sample from the calibration curve. Overcome instrumental drift by con-
ducting the absorbance measurements of blank, calibration standards,
and samples frequently and without undue delay. Record multiple readings
(three or more) for averaging." (Standard Methods, 13th Ed., 1971,
p. 213).
The determination of arsenic and selenium by AA using the gaseous
hydride method may not be satisfactory, since reduction to the trivalent
form with SnCl2 may not be complete. The conversion to gaseous arsine
after addition of zinc metal may also not be complete. Colorimetric
methods are therefore recommended. The analysis of mercury by AA with
the cold vapor technique, also depends on the reduction of the sample
with SnS04 or SnCl2> which may not be complete when other oxidants in
high concentrations are present.
107
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SECTION 9
BIOLOGICAL PARAMETERS
The biological parameters indicate the presence and action of bacteria
and as such should complement analysis of physical and chemical parameters
in leachate. The biological properties of leachate should reflect the
analysis of specific chemical constituents. Acid fermenting bacteria for
example are expected to be found when the free volatile fatty acids
experience high concentrations, while anaerobic methane fermenting bacteria
are expected when free volatile fatty acids are decreasing in concentration
in the leachate. Since the free volatile fatty acids are more biodegradable
than other chemical components present in leachate the oxygen demand exerted
by bacteria during aerobic decomposition of the substrate, a biological
parameter, will parallel the concentration of free volatile fatty acids,
a chemical parameter.
9.1 THE BOD DETERMINATION
Principle
The Biochemical Oxygen Demand determination is a bioassay type procedure
and measures the oxygen demand exerted by microorganisms during uptake of
degradable substrates and by chemical oxidation reactions. The sample is
incubated under aerobic conditions in the dark at 20° C during a five day
period.
Interferences
Relative low results are obtained with the test when toxic compounds
are present that inhibit the bacterial population or when a biomass is used
that is not adopted to the specific substrate.
Previous Studies
In the early studies by Merz (1954) the leachate was seeded with settled
sewage to establish an aerobic biomass. Later studies by Qasim (1965),
Fungaroli (1971), and the EPA Solid and Hazardous Waste Research Laboratory
(Appendix A) omitted this step. Recent studies, County of Sonoma, Emcon
Associates, 1973; Foree and Cook, 1972; and Mao and Pohland, 1973, however,
have included this step. Most studies ran the test for five days but Hughes
e_t a_l_. (1971) selected a 20 day incubation period possibly including a
nitrification step, since his BOD values were sometimes larger than the
COD values. The DO in the BOD bottles is generally determined with the Azide
modification or using a electrometric DO probe.
The effect of omitting the seeding step in the BOD test to introduce
aerobic bacteria was illusted by the data from Cook (1966). The study
showed that the BOD/COD ratio was 0.095 for an anaerobic leachate sample
collected within a landfill and 0.23 for a leachate sample generated under
108
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aerobic conditions collected at the outer edges of the fill. The two
samples, however, had similar COD values and were equally biodegradable,
since aeration at room temperature caused a 40 percent COD decrease
after five days in both samples. The BOD values and the BOD/COD ratios
should, therefore, be equal, but this was not observed since the anaerobic
leachate sample was not seeded by aerobic bacteria. The effect of seed
omission in the anaerobic sample was further illustrated in the cumula-
tive oxygen uptake as measured with the Hach apparatus which only showed
a significant increase after an eight day lag period, while the leachate
sample generated under aerobic conditions and having an aerobic biomass
showed such increase after only 4 days.
Evaluation of the Method
Evaluation of the BOD test shows that the outcome of it is dependent
on the dilution used. For example, Figure 35 shows that the undiluted
leachate sample (NW-17) from an old fill in N. E. Illinois has a five-day
oxygen demand of 4.5 mg/£. The 5 day oxygen demand of the 0.19 mg/l seed
added to the test was 0.60 mg/l. This results in an actual BODs of 4.5
minus 0.60 is equal to 3.9 mg/l. A BOD/COD ratio of 0.048 was obtained
with this BOD value and the known COD of the sample. The 1:8 diluted
sample, however, had a five-day oxygen demand of 3.72 mg/l or a net 6005
(3.72-0.60=) 3.12 mg/l. By converting this value on the basis of an
undiluted sample, this would represent a BODs of 25 mg/£ which is six
times higher than measured with the undiluted sample. As no inhibitor
was added, the oxygen demand in the diluted bottles may partially be due
to nitrification.
This discrepancy in the outcome of the BOD test was not found when
a high strength leachate sample was tested. Figure 36 shows that the
calculated oxygen demand of the 1:1500 and 1:4000 dilution of the two
seeded Sonoma samples are comparable, while the 1:2500 dilution gave a
slightly higher value. The 1:500 dilution oxygen demand exceeded the
dissolved oxygen present in the sample and therefore can not be used for
the BOD calculation. The spread in BOD data is substantial, with the
highest calculated BOD value 40 percent higher than the lowest one for
the two samples. Since the organic matter is biodegradable, most of the
oxygen demand is consumed within the first two days, while the period of
2 to 5 days is probably used to degrade excreted intermediates and stored
intracellular materials. The rapid oxygen uptake also indicates that
this leachate sample is rather treated by biological means than by physical-
chemical processes. The leachate of the old fill, however, is not subject
to rapid biological degradation and is preferably treated by physical
chemical processes.
If a detailed approach, such as serial dilutions studied here, is
not taken, the dilution factor at which the test was conducted should be
stated clearly, since the uptake rate is concentration dependent as
109
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Figure 36. The DO Uptake as Affected by the Dilution
Used, As Measured in a Leachate Sample from
a Fill Recently Generating Leachate
111
-------
generally expressed by Monod kinetics (Gaudy, 1972). It should be
realized that the outcome of the test only gives an indication of the
amount of biodegradable organic matter present in the diluted sample.
More reliable and accurate parameters would be obtained by analyzing
leachate for the specific biodegradable compounds, such as free volatile
fatty acids, TOC removal of the leachate sample after batch activated
sludge treatment, or expressing the BOD test in terms of Monod para-
meters.
Recommendations
It is recommended that the BOD test be run according to Standard
Methods and that the dilution water be seeded with settled sewage. BOD
values obtained should be judged carefully and be determined parallel
with comparable chemical tests such as free colatile fatty acids, COD
or TOC.
Reagents
"Distilled water: Water used for solutions and for preparation of
dilution water must be of the highest quality, distilled from a block
tin or all-glass still; it must contain less than 0.01 mg/£ copper and
be free of chlorine, chloramines, caustic alkalinity, organic material
or acids.
Phosphate buffer solution: Dissolve 8.5 g potassium dihydrogen
phosphate, KH2P04, 71.75 g dipotassium hydrogen phosphate, K2HP04,
33.4 g disodium hydrogen phosphate heptahydrate, Na2HP04 • 7H20, and
1.7 g ammonium chloride, NfyCl, in about 500 mi distilled water and
dilute to 1 t. The pH of this buffer should be 7.2 without further
adjustment. Discard the reagent (or any of the following reagents)
if there is any sign of biological growth in the stock bottle.
Magnesium sulfate solution: Dissolve 22.5 g MgS04 • 7H20 in dis-
tilled water and dilute to 1 £.
Ferric chloride solution: Dissolve 0.25 g FeCl3 • 6^0 in distilled
water and dilute to 1 £.
Seeding: The purpose of seeding is to introduce into the sample a
biological population capable of oxidizing the organic matter in the
wastewater.
When there is reason to believe that the sample contains very few
microorganisms, the dilution should be seeded. The standard seed mater-
ial is settled domestic sewage which has been stored at 20° C for 24-36
hrs. The standard seed concentration is 1-2 m£ per liter of dilution
water." (Standard Methods. 13th Ed., 1971, pp. 489-490).
112
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Procedures
"Preparation of Dilution Water - Before use, store the distilled
water in cotton-plugged bottles long enough to permit it to become
saturated with DO; or, if such storage is not practical, saturate the
water by shaking the partially filled bottle or by aerating with a
supply of clean compressed air. The distilled water should be at
20 ± 1° C.
Place the desired volume of distilled water in a suitable bottle
and add 1 m£ each of phosphate buffer, magnesium sulfate, calcium
chloride and ferric chloride solutions for each liter of water. If
dilution water is to be stored in the incubator, add the phosphate
buffer just prior to using the dilution water.
If the dilution water is seeded, it should be used the same day
it is prepared.
Dilution technique: Make several dilutions of the prepared sample
so as to obtain the required oxygen depletion. The dilutions to be
used should be based on COD or TOC determinations. In leachate from
a recently generating fill the BOD concentration can approach 70 percent
to 80 percent of the COD value. In such samples, the COD value is
generally three times higher than the TOC. in biologically stabilized
leachate the BOD may only represent a few percentages of the COD value,
as indicated in section 9.1. The dilutions should be chosen such that
the oxygen uptake in the diluted sample is less than 7 rng/£.
Carefully siphon standard dilution water into a graduated cylinder
of 1,000-2,000 ml capacity, filling the cylinder half full without en-
trainment of air. Add the quantity of carefully mixed sample to make the
desired dilution and dilute to the appropriate level with dilution water.
Mix well with a plunger-type mixing rod, avoiding entrainment of air.
Siphon the mixed dilution into two BOD bottles, one for incubation and
the other for determination of the initial DO in the mixture; stopper
tightly and incubate for 5 days at 20° C. The BOD bottles should be
water-sealed by inversion in a tray of water in the incubator or by
use of a special water-seal bottle. Prepare succeeding dilutions of
lower concentration in the same manner or by adding dilution water to
the unused portion of the preceding dilution.
The dilution technic may be greatly simplified when suitable amounts
of sample are measured directly into bottles of known capacity with a
large-tip volumetric pipet and the bottle is filled with sufficient
dilution water that the stopper can be inserted without leaving air
bubbles. Dilutions greater than 1:100 should be made by diluting the
waste in a volumetric flask before it is added to the incubation bottles
for final dilution.
113
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Since some of the constituents in leachate such as ferrous iron
and sulfide may pose an immediate oxygen demand, the determination of
the initial DO should be executed immediately after addition of the
diluted sample to the BOD bottle.
Incubation: Incubate the blank dilution water and the diluted
samples for 5 days in the dark at 20° C. Then determine the DO in the
incubated samples and the blank, using the azide modification of the
iodometric method or a membrane electrode. Those dilutions showing
a residual DO of at least 1 mg/£ and a depletion of at least 2 mg/l
should be considered the most reliable.
Seed Correction: Determine the oxygen depletion of the seed by
setting up a separate series of seed dilutions and selecting those
resulting in 40-70 percent oxygen depletions in 5 days. One of these
depletions is then used to calculate the correction due to the small
amount of seed in the dilution water. Do not use the seeded blank for
seed correction because the 5-day seeded dilution water blank is
subject to erratic oxidation due to the very high dilution of seed,
which is not characteristic of the seeded sample.
Dilution Water Control: Fill two BOD bottles with unseeded dilu-
tion water. Stopper and water-seal one of these for incubation. The
other bottle is for determining the DO before incubation. The DO
results on these two bottles are used as a rough check on the quality
of the unseeded dilution water. The depletion obtained should not be
used as a blank correction; it should not be more than 0.2 ml and pre-
ferably not more than 0.1 ml.
Glucose-Glutamic Acid Check: The BOD test is a bioassay procedure;
consequently, the results obtained are influenced greatly by the pre-
sence of toxic substances or the use of a poor seeding material.
Experience has shown that distilled waters are frequently contaminated
with toxic substances - most often copper - and that some sewage seeds
are relatively inactive. The results obtained with such waters are
always low.
The quality of the dilution water, the effectiveness of the seed,
and the technic of the analyst should be checked periodically by using
pure organic compounds on which the BOD is known or determinable. If
a particular organic compound is known to be present such as acetic
acid, it may well serve as a control on the seed used. There have been
a number of organic compounds proposed, such as glucose or glutamic
acid. For general BOD work, a mixture of these (150 mg/£ of each) has
certain advantages. It must be understood that glucose has an excep-
tionally high and variable oxidation rate with relatively simple seeds.
When used with glutamic acid, the oxidation rate is stabilized.
114
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To check the dilution water, the seed material, and the technic
of the analyst, prepare a standard solution containing 150 mg/£ each
of reagent-grade glucose and glutamic acid which have been dried at 103° C
for 1 hr. Pipet 5.0 m£ of this solution into calibrated incubation bottles,
fill with seeded dilution water, and incubate with seed control at 20° C
for 5 days. On the basis of a mixed primary standard containing 150 mg/£
each of glucose and glutamic acid, the 5-day BOD varies in magnitude
according to the type of seed, and precision varies with the quality of
seed. "Definition:
D] = DO of diluted sample directly after preparation
D£ = DO of diluted sample after incubation
P = decimal fraction of sample used
BT = DO of dilution of seed control before incubation
82 = DO of dilution of seed control after incubation
f = ratio of seed in sample to seed in control
_ % seed in PI
% seed in B]
Seed correction = (B-| - B2)f
Biochemical oxygen demand: When using seeded dilution water:
(D, - D9) - (B, - Bjf
BOD = —! =— — "
(Standard Methods. 13th Ed., 1971, p. 490-494).
9.2 THE COLIFORM DETERMINATION
Principle
The coliform group comprises all of the aerobic and facultative
anaerobic gram negative, non-spore forming, rod shaped bacteria which
ferment lactose with gas formation within 48 hr. at 35° C as deter-
mined with the multiple tube fermentation technique. When using the
rapid and more reproducible membrane filter technique (APHA, 1971)
this group is defined as all the aerobic and facultative anaerobic gram
negative non-spore forming, rod shaped bacteria which produce a
metallic sheen within 24 hours in an endo-type medium containing
lactose. The fecal coliform test differentiates between coliforms of
fecal origin and originating from warm blooded animals using a con-
firmatory test incubated at elevated temperatures.
Interferences
The results of the examination with the multiple tube technique
are expressed in terms of a statistical Most Probable Number (MPN)
115
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and the estimate generally tends to be greater than the actual numbers
(APHA, 1971). An observed limitation of the membrane filter technique
is its reduced ability to detect bacteria in turbid samples- or in the
presence of high concentrations of noncoliform bacteria.
Previous Studies
Only a limited number of studies (Appendix A) measured this para-
meter and generally used the multiple tube fermentation technique as
opposed to the membrane filter technique.
A comparison by Smith (1972) of the Most Probable Number (MPN)
technique with the Membrane Filtration Technique (MF) showed that gen-
erally higher readings were obtained with the former method (Figure
37), due to the elaborate enumeration step incorporated in the method.
The results of the MPN test are two log cycles higher than the MF test
at high coliform concentrations, but are approximately half a log cycle
higher at low coliform concentrations. The enumeration step also
enables the MPN method to determine low concentrations of bacteria that
may not register on the MF test (Smith, 1972). On the other hand the
MF method is more precise since it determines actual numbers while the
MPN method indicates the expected concentration within certain confidence
limits. Glotzbecker (1974) reached a similar conclusion and found that
the MPN technique gave results about two log cycles higher than the MF
technique at densities of 108-109 MPN/100 m£. The two studies did not
make a comparison of the MPN and MF methods by analyzing a buffer solu-
tion spiked with bacteria in order to determine whether the discrepancy
of the two methods is either due to the characteristics of the method
itself or of the leachate characteristics.
Evaluation of Method
To determine whether any of the above results are due to the lea-
chate characteristics, the MF method was tested using both leachate
and phosphate buffer to compare the recoveries in each solution. In
order to evaluate the effectiveness of the MF procedure, the recovery
was tested when bacteria of known concentrations were added to leachate
and directly analyzed with the MF technique (Engelbrecht and Amirhor,
1975). The analysis of the leachate sample was conducted immediately
after addition of the standard amount to prevent the known logarithmic
inactivation of bacteria with time. The leachate was also analyzed
before addition of the stock solution to ensure that all bacteria
were present at concentrations below their detectable limits. A
buffer solution was used as control to which an identical amount of
stock solution was added.
116
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The results in Figure 38 (Engelbrecht and Amirhor, 1975) indicate
that generally less than 100 percent of salmonella, fecal coliform and
fecal streptococci are recovered from the leachate as compared to the
buffer solution. The maximum decrease in recovery is approximately
half a log cycle. Several samples, however, show a 100 percent or
more recovery, indicating that the leachate only causes a relative small
decrease in recovery.
The recoveries generally increased when the leachate was centrifuged
to remove suspended solids, indicating that the suspended solids slightly
interfere in the ability of the MF technique to recover 100 percent of
the added bacteria. The recovery also tended to be larger for the high
molecular weight organic fraction (retentate of the 500 MW membranes
ultrafiltration step) as compared to the low molecular weight fraction
(permeate of the 500 MM membrane ultrafiltration step), possibly indica-
ting that the exposure of the bacteria to fatty acids and heavy metals
might result in a small instantaneous inactivation. The recoveries also
tended to be larger at higher initial bacterial concentrations, indicating-
that the MF might be more accurate at high bacterial concentrations as
opposed to low concentrations. The higher precision of the MF method
is illustrated by the relative small scattering of the data in Figure 38,
all determined by the MF technique, as compared to the relative larger
scattering in Figure 37, using both MF and MPN technique. The above
results tentatively indicate that the MF technique results in slightly
lower bacterial densities when analyzing leachate as compared to analyz-
ing a buffer solution used as a control. This is possibly due to the
presence of suspended solids, which are not expected to similarly affect
the MPN technique. The observed immediate inactivation possibly due to
fatty acids and heavy metals is expected to cause an identical decrease
when using either the MPN or MF technique. It may therefore be con-
cluded that only a part of the two log cycle differences between MPN and
MF, to maximum of 25 percent, is due to leachate characteristics such
as the presence of suspended solids, while the main difference is due
to the different nature of the two tests, i.e. the inclusion of an enumera-
tion step in the MPN method.
Recommendations
The MPN technique should be selected for leachate monitoring purposes
as opposed to the MF technique, since it is able to detect bacteria at
lower concentrations and is less subject to suspended solids interference.
Inactivation studies, however, in which a certain amount of bacteria is
added to a sample to study its subsequent reduction with time, should be
conducted with the MF technique.
118
-------
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Reagents
Most studies evaluated generally use lauryl tryptose broth and
sometimes lactose broth for the presumative total co'iform test in leachate
(Blannon and Peterson, 1973; Appendix A). When 1 ml or less of sample is
added to 10 ml of medium, 35.6 g/1 dehydrated lauryl tryptose broth is
measured. When 10 ml inocculum is added to 10 ml of medium double the
amount is measured (APHA, 1971).
Most studies use brilliant green lactose bile broth and sometimes
endo agar plates for the confirmatory test in leachate (Blannon and Peterson,
1973; Appendix A). The medium consists of 10 g peptose, 10 g lactose, 10 g
oxgall, 13.3 mg brilliant green in 1 £ of distilled water (APHA, 1971).
Most studies that test for fecal coliforms use EC medium (Blannon and
Peterson, 1973; Appendix A) consisting of .20 g Tryptose, 5 g lactose, 1.5
g bile salts, 4 g dipotassium hydrogen phosphate, 1.5 g potassium dihydrogen
phosphate and 5 g sodium chloride in 1 £, distilled water.
Procedures of Presumptive Test for Total Coliforms
"Inoculate a series of fermentation tubes, 'primary' fermentation tubes,
with appropriate graduated quantities, of the water to be tested. The
portions of the water sample used for inoculating the lauryl tryptose broth
fermentation tubes will vary in size and number with the character of the
water under examination, but should be decimal multiples and submultiples
of 1 ml. These should be selected in accordance with the discussion of the
multiple-tube test above.
Incubate the inoculated fermentation tubes at 35 + 0.5°C. After
shaking gently, examine each tube at the end of 24 ± 2 hrs and, if no gas
has formed and been trapped in the inverted vial, again at the end of 48 ± 3
hr. Record the presence or absence of gas formation at each examination of
the tubes, regardless of the amount.
Formation within 48 ± 3 hr of gas in any amount in the inner fermentation
tubes or vials constitutes a positive Presumptive Test." (Standard Methods,
13th Ed., 1971, pp. 664-665).
Procedures of Confirmed Test for Total Coliforms
"Submit all primary fermentation tubes showing any amount of gas at the
end of 24 hr of incubation to the confirmed test. If active fermentation
appears in the primary fermentation tube before expiration of the 24 hr
period of incubation, it is preferable to transfer to the confirmatory medium
without waiting for the full 24-hr period to elapse. If additional primary
fermentation tubes show gas production at the end of 48-hr incubation, these
too shall be submitted to the confirmed test.
Gently shake or rotate primary fermentation tube showing gas and with a
sterile metal loop, 3 mm in diameter, transfer one to three loopfuls of medium
to a fermentation tube containing brilliant green lactose bile broth
120
-------
Incubation - Incubate the inoculated brilliant green lactose bile
broth tube for 48 ± 3 hrs at 35 ± 0.5° C.
Interpretation - The formation of gas in any amount in the inverted
vial of the brilliant green lactose bile broth fermentation tube at any
time within 48 ± 3 hr constitutes a positive Confirmed Test." (Standard^
Methods, 13th Ed., 1971, pp. 665-666). The calculation of the Most prob-
able Number should proceed according to Standard Methods (APHA, 1971)
using probability tables. The complete coliform test should be con-
ducted in those instances where leachate causes pollution of drinking
water supplies.
Procedures for the Fecal Coliform Test
"Transfers should be made from all positive presumptive tubes to
EC medium. This examination may be performed simultaneously with the
confirmatory procedure using brilliant green lactose bile broth. Use
a sterile metal loop with a minimum 3 mm diameter to transfer from the
positive fermentation tube to EC medium. When making such transfers,
first gently shake the presumptive tube or mix by rotating. Inoculated
tubes are incubated in a water bath at 44.5 ± 0.2° C for 24 ± 2 hrs.
All EC tubes must be placed in the water bath within 30 min after plating.
The water depth in the incubator should be sufficient to immerse tubes
to the upper level of the medium.
Interpretation - Gas production in a fermentation tube within 24 hr
or less is considered a positive reaction indicating fecal origin.
Failure to produce gas (growth sometimes occurs) constitutes a negative
reaction indicating a source other than the intestinal tract of warm-
blooded animals." (Standard Methods. 13th Ed., 1971, p. 669). Fecal
coliform densities are calculated as Most Probable Number using prob-
ability tables in Standard Methods (APHA, 1971).
121
-------
SECTION 10
MISCELLANEOUS DETERMINATIONS
Only very few studies measured parameters not discussed earlier. Only
two studies measured LAS while another study measured MBAS. Two studies
measured CN while one study measured F. Three studies measured the DO but
this parameter is less useful than the ORP and is therefore not recommended.
Two studies measured sulfides, while one study measured Si02- One study
measured hexane solubles while another measured ether solubles, however,
the weight of both extractions is enhanced by the presence of free volatile
fatty acids (Appendix A).
The color parameter has been determined in some of the studies and may
have potential as an indicator parameter to signal high organic matter
concentration. Since turbidity is sometimes difficult to remove from
leachate samples, the method will only record apparent color. Because of
its inaccuracy the platinum cobalt method is not recommended. The EPA
(1974) recommends the spectrophotometric method by measuring transmittance
at several wavelengths. Technicon (1973) recommends absorbance readings
at 400 nm and using platinum cobalt as standard curve.
Several studies report the visual appearance and odor of the leachate
sample before analysis and such evaluation is useful since it gives a
general characterization while it is not time consuming.
122
-------
SECTION 11
REFERENCES
Anon., "Abandoned Limestone Quarry at Montgomery County Recreated into
Showplace Landfill Operation," Constructioneer. Jan. 10 (1972).
ASTM "Standard Method of Test for Phosphate Industrial Water," in 1969 Book
of ASTM Standards. Pt. 23, D515-68, Sec 1-39, pp 43-53, American Society
for Testing and Materials, Philadelphia, Pennsylvania (1969).
Apgar, M.A., and Langrnuir, D., "Groundwater Pollution Potential of a
Landfill Above the Water Table," Groundwater, 9_, pp 76-96 (1971).
APHA, "Standard Methods for the Examination of Water and Wastewater," 13th
Ed. American Public Health Association, Washington, D.C. (1971).
Blannon, J.C., and Peterson, M.L., "Survival of Fecal Coliforms and Fecal
Streptococci in a Sanitary Landfill," Report at Solid Hazardous Waste
Research Laboratory, U.S. Environmental Protection Agency, Cincinnati,
Ohio (1973).
Brown, E., et_ al_., "Methods for Collection and Analysis of Water
Samples for Dissolved Minerals and Gasses," in Techniques of Water
Resources Investigations of the U.S. Geological Survey, Chapter 1,
i>. beologi
, D.C., K
U.S. Geological Survey, Washington, D.C., 160 p. (1970).
Chian, E.S.K., and DeWalle, F.B., "Treatment of Leachate from Landfills,"
First Annual Report, Contract 68-03-0162, Solid and Hazardous Waste
Research Laboratory, U.S. EPA, Cincinnati, Ohio (1975).
Cook, A.A., "Microbiological and Chemical Investigation of Seepage from
a Sanitary Landfill," M.Sc. Thesis, Department of Civil Engineering,
University of West Virginia, Morgantown, West Virginia, 71 p. (1966).
Cressman, B., "Officials Tour Bucks Leachate Plant," in The Morning Call,
Allentown, Pa., Oct. 5 (1973).
Engelbrecht, R.S., and Amirhor, P., "Stability of Bacteria and Viruses in
Sanitary Landfill Leachate," Report submitted to Diaper Research Committee,
Tissue Division, American Paper Institute, Inc., New York (1975).
The Environmental Protection Agency, "Methods for Chemical Analysis of
Water and Wastes," U.S. EPA, Office of Technology Transfer, Washington,
D.C. (1974).
123
-------
Foree, E.G., and Cook, E.A., "Aerobic Biological Stabilization of Sanitary
Landfill Leachate," Report UKY-TR58-72-CE21, College of Engineering,
University of Kentucky, Lexington, 43 pp (1972).
Fungaroli, A.A., "Pollution of Subsurface Water by Sanitary Landfills,"
Report SW-12 g, pp 186, U.S. EPA, Washington, D.C., (1971).
Gaudy, A.F., "Biochemical Oxygen Demand," in Water Pollution Mi crobiology
Ed. Mitchell, R., Wiley Interscience, New York (1972),
Glotzbecker, R.A., "Presence and Survival in Landfill Leachates and
Migration through Soil Columns of Bacterial Indicators of Fecal Pollution,"
M. Sc. Thesis, Dept. of Civil Engineering, University of Cincinnnati,
Cincinnati, Ohio 122 p. (1974).
Hach, "Water Analysis Handbook," Hach Chemical Company, Ames, Iowa, (1973).
Hughes, G.M., et a]_., "Hydrogeology of Solid Waste Disposal Sites in
Northeastern Illinois," Report SW-12d, U.S. EPA, Washington, D.C., pp. 154
(1971).
Illinois State of - "Solid Waste Rules and Regulations," Illinois EPA,
Division of Land Pollution Control, Springfield, 111., (1973).
Kaylor, W.H., "Determination of the Phosphate in Solid Waste Using the
Vanadomolybdophosphate Acid Method," Solid Hazardous Waste Research
Laboratory, U.S. EPA, Cincinnati, Ohio, 10 p. (1971).
"Manual for Chloride Electrode," Orion Research, Inc., Cambridge, Mass.,
(1973).
Mao, M.C.M. and Pohland, F.G., "Continuing Investigations on Landfill
Stabilization with Leachate Recirculation, Neutralization and Sludge
Seeding," Special Research Report, School of Civil Engineering, Georgia
Institute of Technology, 79 pp., (1973).
Merz, R.C., "Final Report on the Investigation of Leaching of a Sanitary
Landfill," Publication No. 10, California State Water Pollution Control
Board, Sacramento, Ca., 91 p. (1954).
Parker, C.R., "Water Analysis by Atomic Absorption Spectroscopy," Varian
Techtron, Palo Alto, Ca., 78 p. (1972).
Pohland, F.G., "Landfill Stabilization with Leachate Recycle," Interim
Progress Report, Grant EP 00658-01, Solid Hazardous Waste Research
Laboratory, U.S. EPA, 51 pp. (1972).
Qasim, S.R., "Chemical Characteristics of Seepage Water from Simulated
Landfills," Ph.D. Dissertation, University of West Virginia, Morgantown
W. Virginia, 145 p. (1965).
124
-------
Rich, C.I., "Elemental Analysis by Flame Photometry," in Methods of
Soil Analysis, Part 2, Chemical and Microbiological Properties, Ed. Black,
C.A., Amer. Soc. of Agron., Madison, Wisconsin, (T965).
Smith, L., "A Brief Evaluation of Two Methods for Total and Fecal
Coliforms in Municipal Solid Waste and Related Materials," Internal
Report Solid and Hazardous Waste Research Laboratory, U.S. EPA, Cincinnati
(1972).
Schoenberger, R.J. ejt al_., "Treatment and Disposal of Sanitary Landfill
Leachate," Proceedings 5th Mid-Atlantic Industrial Waste Conference, Drexel
University, Philadelphia, Pa. (1971).
Sonoma,County of -Emcon Associates, "Sonoma County Refuse Stabilization
Study," Second Annual Report, County of Sonoma, Dept. of Public Works,
Santa Rosa, California (1973).
Technicon, "Technicon Autoanalyzer II," Technicon Instruments Corp.,
Tarrytown, N.Y. (1973).
Ulmer, N.S., "Physical, Chemical and Microbiological Methods of Solid
Waste Testing; Four Additional Procedures," U.S. EPA, NERC, Cincinnati,
46 pp. (1974).
Wilson, D.A. "Sulfate Determination, Procedure for Determination in
Solid and Liquid Samples," Internal Report, Solid Hazardous Waste Research
Laboratory, U.S. EPA, Cincinnati, Ohio (1972).
125
-------
SECTION 12
APPENDIX A
Survey of physical, chemical, and biological methods used by
various investigators.
126
-------
Parameter
Apgar and Langmuir (1971)
Method
PH
Oxidation/Red.
Potent.
Conductivity
Total Solids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphate
Alkalinity/Acidity
Nitrate
Nitrite
Ammonia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Coliform
Standard Plate Count
Gasses
Miscellaneous
-1
Combination glass electrode, Sargent Welch PBX
Pt and Kalomel electrode; Beckman Model G
Beckman cond. meter Model RC-1982, cell constant l.cm
N/A*
N/A
N/A
N/A
N/A
N/A
N/A
AgN03 titration
Turbidimetric method
SnCl2 Method
Titration to pH 4.5
Specific ion electrode; phenol disulfonic acid
Sulfanilic method
Nessler method
Flame photometer
Atomic absorption
N/A
Fe, metals with atomic absorption on acidified samples
DO measured in diluted leachate
N/A
N/A
N/A
Temperature DO color (qual.); odor (qual.); turbidity
(qual.)
N/A parameter was not analyzed for
127
-------
Parameter
Black and Veatch/Charleston Labs
Method
PH
Oxidation-Reduction Pot.
Conductivity
Total Solids, Volatile
Suspended Solids, Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sul fates
Phosphates
Alkalinity, Acidity
Nitrates
Nitrites
Aimonia-N
Na, K
Ca
Mg
Hardness
Heavy Metals
Biochemical Oxygen Demand
Coliforms
Total Plate Count
Gasses
Glass electrodes
N/A
N/A
Constant weight at 105° C
N/A
Dichromate
N/A
N/A
N/A
Kjeldahl digestion and distillation
Argentometric method with
BaSO. turbidimetric
method for ortho-P
Methyl orange endpoint
N/A
N/A
Kjeldahl distillation
Flame photometry
Ca with permanganate titrimetric method
Mg with gravimetric method using
di ammonium hydrogen phosphate
EDTA titration
Mn with persulfate method; Zn with
dithizon method; Cd with dithizone method;
Pb with dithizone method; B with carmine
method; Cr with diphenyl carbazide method;
As with diethyldithiocarbamate method
N/A
N/A
N/A
N/A
128
-------
Cameron and McDonald (1974)
Parameter Method
pH Glass electrode, SCE-
ORP N/A
Conductivity N/A
Total Solids
Volatile 105° C overnite, 550° C for 1 hr
Suspended Solids
Volatile Glass fiber filter
Chemical Oxygen
Demand Dichromate
Total Organic Carbon Beckman TOC analyzer, inorganic channels fouled by leachate
Volatile Acids N/A
Tannins, Lignins Folin-Dennis test, color reading after 10 minutes
Organic-N Kjeldahl, distillation
Chlorides Specific ion electrode with 1:1 sample diluted 1 M KN03
Sulfates Bad- added to precip SO,, excess Ba with AA or turbidimetric
Phosphate SnCl-, persulfate digestion for 30 min at 15 psi
Alkalinity/Acidity Titrated to pH 3.7 and 8.3
Nitrate Cu, Cd reduction with autoanalyzer, determined immediately
after collection
Nitrite Cu/Cd reduction
Ammonia N Distillation, titration or specific ion electrode at pH 11
Na, K Atomic absorption spectroscopy
Ca, Mg Atomic absorption spectroscopy
Hardness From individ. ions
Heavy Metals Jarre! Ash MV-500 AA; background correction at nonabsorbing
bordering line Pb, Cr, Ti, Mo, V concentrated with BiNOs
coprecipitation at pH 5.5 after acid digestion; No modification
for Cd, Cu, Ni, Be and Ba; 4:1 cone HC1/HN03 acid digestion
at 5% of sample volume; Hg with flatneless AA immed. after
collection; Ba with AA and 2000 mg/1 K. As with diethyl-
dithiocarbamate method immed. after collection, B with
curcumin after filtration of alcohol solution, Se with AA as
hydrogen selenide.
Biochemical Oxygen
Demand DO probe or Azide modification; no seeding; BODs is 75% of BOD2-
Coliform MPN immed. after collection
129
-------
Cameron and McDonald (1974)
Parameter Method
Standard Plate Count N/A
Gasses Fisher gas partitioner for C02, N2, 03, CHa and HgS 200 ma
filament current; helium flow 30 ml/min; 12 feet 15% Ucon 50-
HB 280 on 40/60 mesh teflon Pb, 5 feet Chromasorb P, 7 feet
molecular sieve 13X
Miscellaneous CN determ. immed. after collect, with distillation; Color with
Hellige Aquatester; F with specific ion electrode after ionic
strength adjustment with 10 g/1 cyclohexylene dimitrilotetraacetate
acid (CDTA); S= with distillation and titration
130
-------
(Man and DeMalle (1973)
Parameter
Method
PH
Oxidation/Red.
Potent.
Conductivity
Total Solids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphate
Alkalinity/Acidity
Nitrate
Nitrite
Ammonia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Coliform
Standard Plate Count
Gasses
Miscellaneous
Glass electrode, Beckman Zeromatic SS-3 pH meter
Pt and Kalomel electrode
Yellow Springs
Drying to constant weight at 105° C, 1 hr at 550° C
Glass fiber filter, GFC Whatman, constant weight at 105° C,
1 hr at 550° C
Dichromate reflux
Beckman TOC analyzer IR-215-B acidified sample
Hewlett-Packard Research Chromatograph 5750
Molybdophosphoric acid
Kjeldahl, titration
Potentiometer titration
BaSO. precipitation method
Persulfate digestion and ascorbic acid method
Titration to inflection point of titration curve
Brucine method electrode
Sulfanilic acid
Kjeldahl, titration
Flame photometer, Cs added
Atomic absorption, La added
Calculated from concentrations
Atomic Absorption with standard addition
Seeding/No seeding, Precision Scientific Galvanic Cell DO
meter
Kjeldahl, titration, membrane filter
Bacto plate count agar
Fisher Hamilton gas partitioner
Color absorbance at 400 nm; turbidity
131
-------
Parameter
EPA-SHWRL NERC-Cincinnati; Bramble (1971)
Method
PH
Oxidation/Red.
Poten.
Conductivity
Total Solids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tanntns, Lignins
Organtc-N
Chlorides
Sulfates
Phosphate
Alkalinity
Nitrate
Nitrite
Ammonta-N
Na, K
Ca, Hg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Ooliform
Total Plate Count
Gasses
Miscellaneous
Combination glaselectrode
N/A
Cond. bridge
1 hour at 105°C, 30 min at 600°C
Glass fiber filter in gooch crucible
Dichromate reflux 50 ml sample, 1 g HgS04, 1 g Ag2S04, 25 ml
0.25 N K2Cr207, 70 ml
N/A
N/A
N/A
Kjeldahl, titration
HgN03 titration
Turbidimetric with Hach sulfaver reagent, on filtered samples
Amtnonaphtol sulfuins. acid
Phenol phthalein, methyl orange endpoint
Brucine method; Cd reduction method
Cd reduction method
KjeldaM titration
Flame photometer
Atomic absorptton, Varian Techtron
EDTA titration, CN added; sometimes fading endpoint; filtration
no effect
Perktn Elmer Atomic 303 Absorption, Mn, Fe, In
No seeding; Weston and Stack DO memter and azide modification
of Winkler test; BOD blacktop layer 2340 mg/1 ; middle 3015;
mixed 3320. Winkler/Azide is 10.1% higher than DO meter
Most probable number
N/A
Fisher gas partitioner
Ether extractables
132
-------
Parameter
Fungaroli (1971)
Method
pK
0x1dation/Red.
Poten.
Conductivity
Total Solids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Glass electrode; 102 KN03 Orion reference electrode
instead of calomel
N/A
N/A
Air drying followed by drying to constant weight at 102°C,
10 min at 600°C
Glass fiber filter on Pyrex glass filter holder; GFC-Whatman
glass paper, 1 hr at 103°C, 10 min at 600°C
20 mi sample, 15 mi H2S04 with Ag2S04, 5 mi 0.5 N
0.11 g HgS04 titration with 0.10 N FAS
Total Organic Carbon N/A
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphate
Alkalinity
Nitrate
Nitrite
Aramonta-N
Na, K
Ca, Mg
Hardness
Heavy Metals
N/A
N/A
HgCl2 tablet and 10 mi cone. H2S04 replaces the acid
catalyst; digestion for 90 min.
Orion combined reference - chloride ion electrode with
Beckman expandometric potentiometer
Turbidimetric method measured with Bausch Lamb Spectronic 20
Aminonaphtol sulfonic acid method when high cone, of
organic matter are present; otherwise SnClg method
Titration with 0.02 N H2S04 to pH 4.5
UV absorption at 220 my after acidification, organic matter
interference corrected by measuring at 275 mu
N/A
Kjaldahl, distillate collected in boric acid, titrated to pH 4.5
Flame photometer, Coleman No. 21
Ca with EDTA titration after Mg(OH)2 is precipitated by pH
adjustment; flame photometer
EDTA titration, NaCN buffer
Beckman atomic absorption, 3 mi 1:1 HN03 added for presentation
centrifuged to remove turbidity Fe, Zn, Ni, Cu
Biochemical Oxygen DO measured with Delta Sc DO meter and Winkler azide modification
Demand
Coliform
Total Plate Count
Gasses
Miscellaneous
test; no seeding; elimination of immediate oxygen demand by
preaeration or measuring DO in BOD bottle after 15 min.
N/A
N/A
Fisher Hamilton gas partitioner C02, 0£, N2, H2S, CH4
DO
133
-------
Golueke (1974)
Parameter
Method
pH
Oxidation-Reduction Pot.
Conductivity
Total Sol ids,Volatile
Suspended Solids, Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphates
Alkalinity, Acidity
Nitrates
Nitrites
Ammonia-N
Na, K
Ca
Mg
Hardness
Heavy Metals
Biochemical Oxygen Demand
Coliforms
Total Plate Count
Gasses
Combination electrode radiometer
model 22 pH meter
N/A
YSI Model 31
Dry at 105° C.muffle 1 hr at 580° C
GFC filter dry at 105° C, 1 hr at 580° C
Dlchromate reflux
Beckman TOC analyzer, IR 215
Total;column partition chromatography
N/A
Kjeldahl
Hg(N03)2 titration
Bag$04 precipitation
Ammonium molybdate - strong acid digestion
Titration to pH 4.3
Brucine
N/A
Kjeldahl
Flame protometer, Beckman DV
EDTA titration
EDTA titration
EDTA titration
Atomic absorption
Seeded
N/A
Standard Plate Count
Varion Gas Chromatograph TC Detector
134
-------
Parameter
Ho, Boyle and Ham (1971) Boyle and Ham (1972)
Method
pH
Oxidation/Red. Poten
Conductivity
Total Solids,
Volatile
Suspended Solids
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tanntns, Lignins
Organic-N
Chlorides
Sulfates
Phosphate
Alkalinity
Nitrates
Nitrite
Ammonta-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Col i form
Total Plate Count
Gasses
Orion Research, Inc. lonalizer Model 404
. N/A
Labline Electro MHO meter MC-1; Cell constant 1.0
N/A
N/A
N/A
N/A
N/A
N/A
Kjeldahl digestion with digestion reagent sulfuricacid
HgS04; titration
HgN03 method
N/A
Persulfate digestion SnCl^,organic separation extraction
Titration to pH 4.3
*Keeney digestion with devarde alloy,125 ml erlenmeyer, P
buffer, boric acid
Keeney digestion; MgO added; only NH4, excluding N02» N03
Same as above
N/A
Ca Hardness, Calver-2 No. 281 added (Hach)
CN added; EDTA titration; for total hardness Univer I No.
206 added (Hach)
Fe phenanthroline method
N/A
N/A
N/A
N/A
*Brenner, J. M. and Keeney D. R., "Steam Distillation Method for Determination
of Ammonia, Nitrates and Nitrites," Anal. Chem. Acta, 32, 485-495 (1965).
135
-------
Holzer and Chestnut (1974)
Parameter
Method
pH
Oxidation-Reduction Pot.
Conductivity
Total Solids, Volatile
Suspended Solids, Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphates
Alkalinity, Acidity
Nitrates
Nitrites
Ammonia-N
Na, K
Ca
Mg
Hardness
Heavy Metals
Biochemical Oxygen Demand
Col i forms
Total Plate Cojnt
Gasses
Beckman Instruments, expandomatic pH
meter
N/A
Beckman Instruments RB3, Solu Bridge
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Mercurimetric method
Thorin Method
Only Ortho-P, Phosphomolybate method
Titration to pH = 4.5
Brucine method
N/A
N/A
Atomic adsorption
Atomic adsorption
Atomic adsorption
N/A
Atomic absorption;sample acidified
N/A
N/A
N/k
N/A
136
-------
Parameter
Hughes et al. (1971)
Method
PH
Oxidation/Red.
Potent.
Conductivity
Total Solids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphate
Alkali ni ty/Aci di ty
Nitrate
Nitrite
Ammonia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Col i form
Standard Plate Count
Heavy Metals
Miscellaneous
Glass electrode, Beckman oH meter
N/A
Measured as TDS (NaCl equiv.)
Dried at 105° C
N/A
Dichromate reflux,
added to precipitated
N/A
Hydroxylamine test
N/A
Total Kjeldahl
Hg(N03)2 and argentometric method after filtration
Turbidimetric after filtration
Ascorbic acid
Methylorange titration; potentiometric titration to pH 4.5
Phenol disulfonic method after filtration
Measured with N03
Total Kjeldahl
Na estimated from dissolved fixed residue and hardness
EDTA titration
EDTA titration
Fe with phenanthroline method and tripyridine method, Mn
with persulfate method
20 d. test seeded with sewage
N/A
N/A
Cu, Cd, Pb, Zn, Fe, Cr, Se, Al , As, Be with Jarrel-Ash
Atom. Absorp. Spect. 30 min. digest with ] percent dil .
nitric acid; internal standards for As,B with carmine
method
CN.F MBAS foaming interface hexane sol. fluorescence
137
-------
Parameter
A. W. Martin (1974)
Method
PH
Oxidation/Red.
Potent.
Conductivity
Total Solids,
Volatile
Suspended Solids
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphate
Alkalinity/Acidity
Nitrate
Nitrite
Ammonia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Coliform
Standard Plate Count
Gasses
Miscellaneous
Leeds Northrop pH meter
N/A
N/A
103° C for 60 minutes (two weighings); 550° C for 30
minutes (two weighings)
N/A
Dichromatic; more HgSO. added
N/A
N/A
N/A
Kjeldahl and Nessler
; dichromate endpoint
BaSO. turbidimetric
Persulfate digestion; vanadomolybdate
Methylorgange and phenolphtalen endpoint
Brucine
Sulfanilic acid
Kjeldahl and Nessler
AA
AA
AA
Fe colorimetric, Fe, Pb, Cu, Zn, Ni , Hg, Cr, with AA
Seed from polluted creek; Yellow Spring DO meter
N/A
N/A
N/A
N/A
138
-------
Parameter
Merz (1954)
Method
PH
Oxidation/Red.
Potent.
Conductivity
Total Solids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organ ic-N
Chlorides
Sulfates
Phosphate
Alkalinity/Acidity
Nitrate
Nitrite
Ammonia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Coliform
Standard Plate Count
Gasses
Miscellaneous
Glass electrode, Beckman portable
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Kjeldahl
Mohr's test
turbidimetric method, BaS04 precipitation method
SnCl£ ammonium molybdate method
Volumetric method
Measured
N/A
Kjeldahl
rlame photometer
Mg with Titan-yellow method
Sodium versenate method
Fe with dipyridyl method
Seeded with settled sewage
N/A
N/A
N/A
DO
139
-------
Parameter
Otton and McKenzle, Geological Survey, Portland (1974)
Method
PH
Oxidation-Reduction Pot.
Conductivity
Total Solids, Volatile
Suspended Sol Ids, Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Adds
Tannins, Lignins
Organ1c-N
Chlorides
Sulfates
Phosphates
Alkalinity, Acidity
Nitrates
Nitrites
Ammonia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen Demand
Coliforms
Total Plate Count
Gasses
Sargent Welch- model PBL glass
combination electrode
Beckman
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Mi Hi pore filter;difco media
N/A
N/A
140
-------
Parameter
Pedco Environmental (1974)
Method
PH
Oxidation/Red.
Poten.
Conducti v1 ty
Total SolIds,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphate
Alkalinity
Nitrate
Nitrite
Ammonta-N
Na. K
Ca, Mg
Hardness
Heavy Metals
Blochenrical Oxygen
Demand
Coll form
Total Plate Count
Gasses
Miscellaneous
Glass electrode
N/A
Conductivity meter
Evaporate;! hour at 105°C
0.45 u membrane filter
Dichromate reflux
N/A
N/A
N/A
H2S04 digestion with HgO + K-SO distillation and titration
HgN03
Turbtdimetric
Aminonaphtol sulfonic acid
Titration to pH 4.2 and 8.3
Remove Cl, evaporate sample, add PDSA, heat 15 min 90°C, add
water and NH.OH, read at 410 nm
Sulfanilamide
Distillation and Titration
AA
AA, La added
EDTA titratton
Nitric acid digestion followed by AA
Seeded
N/A
N/A
Chromasorb 102, molecular sieve
141
-------
Parameter
Department of Environmental Resources, Pennsylvania
Method
PH
Oxidation-Reduction Pot.
Conductivity
Total Solids, Volatile
Suspended Solids, Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphates
Alkalinity, Acidity
Nitrates
Mitrites
Ammonia-N
Na, K
Ca, Mg
LTN, Beckman glass electrode
N/A
Aquatronic model 320
Constant weight at 105° C, 1 hr at
550° C
Glass fiber filter GFC Whatman
Dichromate reflux
Beckman TOC analyzer model 915
N/A
V. V. Full Scan
Automated-EPA digestion +
phenol ate including NH4
Automated-EPA ferricyanide
Automated-EPA Bachla
Automated-EPA ascorbic acid
Titration to inflection point
Automated-EPA Cd reduction
(includes nitrite)
Automated-EPA diazatization
includes N03
Automated-EPA phenolate method
Flame photometry Cs added
Atomic absorption La added
Hardness
Heavy Metals
Biochemical Oxygen Demand
Coll forms
Total Plate Count
Gasses
Automated-EPA Calmagite
Atomic Absorption
Seeded
Millipore membrane
142
-------
Parameter
Qasim (1965); Lin (1966)
Method
pH
Oxidation/Red.
Poten.
Conductivity
Total Solids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organtc-N
Chlorides
Sul fates
Phosphate
Alkalinity
Nitrate
Nitrite
Ammonta-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Col i form
Total Plate Count
Gasses
Misc.
Beckman Expendomatic
N/A
N/A
Drying for 1 hour at 103°C; 15 min at 600°C
N/A
N/A
N/A
Stream distillation; Gas Chromatograph; Barber Coleman 5000;
Selecta with H flame detector, recorder and integrator,
recorder and integrator; 162 carbowax 20 M + 2% H3P04 on 60/80 mesh
Tyrosine-Hach method
Kjeldahl digestion
HgN03 titration
Turbidimetric with Hach sulfate reagent
SnCl2
Titration to endpoint determined from titration curve
3.8 and 7.2
Brucine method; aluminum reduction with distillation
Sulfanilic acid
Kjeldahl distillation
Beckman DU flame photometer
Ca with EDTA titration (murexide) Mg with brilliant yellow dye or
calculated for total hardness and Ca-bacteria
EDTA titration chrome Black T
Hach method, Fe with phenanthroline method; phenanthroline method
Al with aluminon, B with Carmine, Cu with Cuprethol, Mn with perjodate
No seeding, DO measured with azide modification
Presumptive test with lactose broth, 35°C for 48 hour; multiple
tube dilution
Trypton glucose yeast agar at 20°C for 48 hour
Beckman GC-2A gas chromatograph with molecular sieve 13x and
silica gel column
ABS with methyl green test; Si 02 with ami no acid method; H?S with
iodine thiosulfate *•
143
-------
Parameter
Rovers and Farquhar (1972)
Method
PH
Oxidation/Red.
Potent.
Conductivity
Total Solids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphate
Alkalinity/Acidity
Nitrate
Nitrite
Ammonia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Col i form
Standard Plate Count
Gasses
Miscellaneous
Glass electrode, anal, immediately
N/A
N/A
Dried to constant weight at 103° C, volatile residues
for 30 min at 600° C
Gooch crucible with asbestos fiber, dried to constant
weight at 103° C
reflux time up to 7 hr. recommended
Technicon Autoanalyzer; digestion with sulfuric acid and
potassium persulfate
Titration
Turbidimetric. gravimetric
Technicon Autoanalyzer total, soluble measured
Titration with H2S04 to pH 4.5 titration with NaOH to 8.3
no inflection point observed
Measured
Measured
Flame photometry
EDTA titration; Fe included
Fe colorimetric; Mn, Cr, Ni, Cd, Cu, Zn by AAS
Acclimated seed recommended
Model 25V Fisher Gas Partitioner; Perkin Elmer Coleman
Recorder, f^S by Drager Multi Gas Detector Model 21/31
144
-------
Sangrey and Bisogni (1974)
Parameter
Method
PH
Oxidation-Reduction Pot.
Conductivity
Total Solids, Volatile
Suspended Solids, Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphates
Alkalinity. Acidity
Nitrates
Nitrites
Ammonia-N
Na, K
Ca
Glass electrode Beckman Zeromatic SS-3
pH meter
N/A
N/A
Drying to constant weight at 105° C, 1
hr at 550° C
Glass fiber filter, GFC Whatman, constant
weight at 105° C, 1 hr at 550° C
Dichromate reflux method
N/A
N/A
N/A
Kjeldahl, Nesslerization
Titration with Mercuric nitrate
BaSO. precipitation
Ami no-reduction molybdenum blue
Titration to inflection point of titration
curve
N/A
N/A
Kjeldahl, Nesslerization
N/A
N/A
Mg
Hardness
Heavy Metals
Biochemical Oxygen Demand
Coliforms
Total Plate Count
Gasses
N/A
N/A
N/A
N/A
N/A
N/A
N/A
145
-------
Parameter
SCS Engineers (1974)
Method
PH
Oxidation/Red.
Potent.
Conductivity
Total Sol Ids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphate
Alkalinity/Acidity
Nitrate
Nitrite
Ammonia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Col i form
Standard Plate Count
Gasses
Miscellaneous
Glass and calomel electrode
Specific conductance
105° C
TFC glass fiber filtration
Dichromate reflux
Total Kjeldahl, digestion, distillation and titration
HgN03
Gravimetric
SnCl2
Brucine
Distillation and titration
EDTA titration
Clear samples acidified, 10 x concentr. pollut. samples nitric/
sulfuric acid digestion, 5 x concentrated no standard addition;
Hg with flameless AA, Se with diaminobenzidine
Measured
Measured
Varian No. 2720, silica gel and molecular sieve for C02,
N2P2, CH4
Polarographic DO meter,settleable solids
146
-------
Parameter
State of New Jersey, Bureau of Solid Waste (1974)
Method
pH
Oxidation/Red.
Poten.
Conductivity
Total Solids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphate
Alkalinity
Nitrate
Nitrite
Ammonia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Coliform
Total Plate Count
Gasses
Miscellaneous
Glass electrode column
N/A
N/A
105°C and 550°C
N/A
Dichromate reflux
N/A
N/A
N/A
Argentometric
Turbidimetric or technicon
SnCl2 or technicon autoanalyzer
N/A
Phenol disulfonic acid or technicon autoanalyzer
N/A
Direct nesslerization
N/A
EDTA
Hg flameless AA, As with Agdiethyl dithiocarbamate, Cd with dithizone
Cr with diphenylcarbazide; Pb, Ni, Zn with AA, Cu with bathocuproine,
Fe with tripyridine method, Mn with periodate, Se with diaminobenzidine
Seeded and azide modification
Total fecal; also fecal streptococcus
N/A
N/A
Color with chloroplatinate method
ether solubles, chlorinated
hydrocarbons, phenols, Cn distillation and pyridine pyrazolore
147
-------
Department of Health, State of New York (1974)
Parameter Method
PH
Oxidation/Red.
Potent.
Conductivity
Total Solids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphate
Alkalinity/Acidity
Nitrate
Nitrite
Ammonia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Col i form
Standard Plate Count
Gasses
Miscellaneous
Glass electrode, Beckman zeromatic
N/A
Beckman RC-16B2
N/A
Glass fiber filter at 105° C, ignition at 550° C
Simplified COD, colorimetric determination of excess
di chroma te
N/A
N/A
N/A
Kjeldahl digestion and titration
Thiocyanide method, Technicon Autoanalyzer
Methyl thymol blue, Technicon Autoanalyzer
Persulfate digestion,ascorbic acid, Technicon Autoanalyzer
Titration to pH 4.5
N/A
Sulfanilic Acid
Indophenol blue, Technicon Autoanalyzer
AA, Varian Tectron
AA
EDTA titration
AA; As with diethyldithiocarbamate
Seeded, yellow spring DO meter
N/A
N/A
N/A
F with specific ion electrode
148
-------
Parameter
VTN Seattle (1974)
Method
PH
Oxidation/Red.
Poten.
Conductivity
Total Solids,
Volatile
Suspended Solids,
Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sul fates
Phosphate
Alkalinity
Nitrate
Nitrite
Ammonia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen
Demand
Coliform
Total Plate Count
Gasses
Miscellaneous
Combination glass electrode Sarge.nt Expanded scale pH meter
N/A
N/A
Dried at 103°C, 30 min at 600°C
Glass fiber filter, Reef Angel in gooch crucibles, dried
at 105° C
Dichromate reflux
Beckman gas TOC analyzer
N/A
N/A
Distillation, digestion and nesslerization
Argentometric, changed to mercuric nitrate
Turbidimetric
SnC72
Titration to pH 4.5; titration to pH 8.3
Modified Brucine (EPA)
N/A
Distillation and nesslerization with Bausch and Lomb Spec-20
Calculated from AA
AA Perttn Elmer 3Q5
Calculated from AA
N/A
Azide modification
MPN
Tryptone glucose agar
Color with spectrophotometer; UV absc.ption with Beckman DS-2A
HgS with methylene blue, LAS with methylene blue
149
-------
SECTION 13
APPENDIX B
Survey and discussion of physical, chemical, and biological methods
used by various investigators.
150
-------
Parameter
Emcon Assoc. (197*) County of Sonoma (1973)
Method
Rational
pH
Oxidation/Reduction Pot.
Conductivity
Total Solids, Volatile
Suspended Solids, Volatile
Chemical Oxygen
Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organ1c-N
Chlorides
Sulfates
Phosphates
Alkalinity, Acidity
Beckman electromate w/NiCd cells
Combination electrode
N/A
Beckman/Solo Bridge
RB3 - U104
Drying to constant weight at 105° C,
1 hr at 550° C
Glass fiber filter, 1 hr at 105" C,
10 min at 600° C
20 ml sample, 10 ml 0.25 N K2Cr207
30 ml H2S04 with Ag2S04
N/A
Column partition chromatographic method
N/A
Kjeldahl, titration
Mercuric nitrate mixed indicator
BaSOa precipitation method with ignition
Sulfuric/nitric acid dig.; vanadomolybd.
phosphoric acid method; read on Beckman
DB.
Titration to pH 4.2
pH meter used in lab and in
field. Results are good
Good results but not easily used
1n field. Have recently purchased
Myron
TDS (not volatile) drying done on
water bath, then in oven over
night. Cooled in desiccator
Tests need care for good reproduci-
bility. GC method is preferable.
Method is very good and reproduci-
ble; foaming is only routine problem.
Ignition method seems best as it
reduced organic precipitation
interference
Acid digestion with vanadate erratic
results. Now changing to ascorbate
method as it is not as sensitive to
pH changes
Nitrates
Nitrite
Ammon1a-N
Na, K
Ca
Mg
Hardness
Heavy Metals
Brudne read on Beckman DB
N/A
Kjeldahl titration
Aeration caused erratic results;
also poor heat control. Method is
good and gives reproducible curves.
Leachate coloration requires
sample blanks always be used.
Method is very good and reproducible;
foaming is only routine problem
AAS No additions dilution & turned flame All photometric methods here are AAS.
EDTA titration, interference for heavy
metals reduced by NaCN buffer
AAS
Total EDTA
5 ml 1:1 HN03 added to 1 i sample;
atomic absorption
Mg is AAS; Ca is by EDTA but will go
to AAS soon.
Total hardness is EDTA.
reduce all problems
CN does not
151
-------
Eneon Assoc. (197 . County of Sonoma (1973
Parameter Method Rational
Biochemical Oxygen Seeding fresh sewage seed. Samples must be highly diluted; some
Demand problems with toxiclty in some leachates
Conforms Presumptive test with lactose broth Col 1 form test done by a sub-
confirmed test with boric acid lactate contracting lab.
broth, multiple tube dilution
Total Plate Count N/A
Gasses VaHan 90-P; TC:1'Silica gel at 80° Columns must be activated for adequate
followed by 20' Mixed Mol Sieve external separation.
for C02. CH4, H2, H2S, 02
152
-------
Parameter
Engineering-Science (1974)
Method
Rational
PH
Oxidation-Reduction Pot.
Conductivity
Total Solids, Volatile
Suspended Solids, Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphates
Alkalinity, Acidity
Nitrates
Nitrites
Aimwnia-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Glass electrode
Pt-Calomel electrode
Conductivity bridge
Drying to constant weight
Glass fiber filters
Bichromate reflux
N/A
N/A
N/A
Kjeldahl, titration
Mercuric nitrate method
Gravimetric with ignition of
residue
Vanadomolybdate phosphoric acid
method
Potentiometric titration to pH 4.5
phenolphthalein titration
Brucine
Sulfanilic acid method
Kjeldahl, titration
Flame photometer, Coleman 20
Atomic Absorption (Flame, LaO added)
Hach
Graphite furnace, atomic absorption
Hg - Cold Vapor
Biochemical Oxygen Demand Five days BOD with multiple dilutions
Azide modification
Conforms
Total Plate Count
Gasses
MPN test
Standard plate count
Gas chromatography, silica gel - mole-
cular sieve
Universal practice
Universal practice
Universal practice
G. F. paper easy to handle
Accurate and precise
Best method
No need for new method
No need for new method
Best method
Data shows it as best method
Only method
Best method
Simple and accurate
Best to date
Simple and accurate
Best to date
DO meters less reliable
Simple and accurate
Simple and accurate
Best accuracy
153
-------
Foree and Reid (1972) Foree and Cook (1972) Foree
Parameter Method
(1974)
Rational
PH
Oxidation/Reduction Pot.
Conductivity
Total Solids, Volatile
Corning Model 10 pH meter; glass
electrode
X/A
Beckman cond. meter RC-16B82
N/A
Suspended Solids, Volatile Glass fiber filter, GC-Whatman; 10
min at 580° C
Chemical Oxygen Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignins
Organlc-N
Chlorides
Sulfates
Beckman TOC analyzer IR-315 acidified
sample
Column partition chromatographic
method
N/A
Kjeldahl
N/A
N/A
Any standard conductivity cell
would be satisfactory
After filtration with Whatman GF/C
glass fiber suspended solids after
constant weight at 103-105° C
volatile suspended solids by burning
for 10 min at 580° C, this gives
essentially the same result as
burning for 15 min at 550° C
Standard Methods COD test is the
best measure of organic strength
of leachate. Results are very
reproducible
Produces good results; gives only
total volatile acids concentration
Mlcrokjeldahl digestion
The BaS04 technique works quite well.
Leachate color could possibly cause
trouble if a spectrophotometer is
used instead of o nephelometcr :r
turbidimeter
Phosphates
Alkalinity
Nitrates
Sample dried with magnesium chloride
and heated for 10 min at 600° C
followed by acid digestion.SnClo
roethodl
Titratlon to pH 8.3 and 4.3
Specific 1on electrode
Used the indicated method for a
number of years and found it to work
well. Is preferred over some of the
other acid digestion methods. How-
ever, the persulfate digestion method
seems to be the most widely accepted
method for wastewater analyses, and
would probably be the method of choice
for leachates.
Titratlon to inflection point of
tltration curve is more correct.
Tltration to pH 8.3 and 4.3 gives
essentially the same results in
most cases.
Chosen for its ease. It produces
reasonably accurate results, chloride
interference is significant in
leachate but is easily removed by
precipitation; the specific ion
electrode method is a viable alter-
native to the Brucine method
Nitrite
N/A
154
-------
Ammonla-N
Nessler method after steam distillation
Na, K
Ca
Mg
Hardness
Heavy Metals
AAS
AAS
N/A
AAS; Fe with colorlmetric method and
AAS
Biochemical Oxygen Demand SM; Azide modifications; DO meter
Conforms
Total Plate Count
Gasses
Membrane filter technique
N/A
Fisher Hamilton gas partitioner
Steam distillation followed by
Nesslerization; there is no
difference between micro and regular
Kjeldahl; nesslerization method has
worked quite well and is preferred over
titration; direct nesslerization for
ammonia-N determinations will not
generally work very well because of
excessive interferences.
Atomic absorption for calcium,
magnesium
Atomic absorption for all heavy
metals; low sensitivity for iron
with atomic absorption
Seeding is definitely called for
in the BOD test because leachates
are normally anaerobic and have
low pH when collected thus potentially
a low population of viable aerobic
organisms; Winkler technique more
reliable than DO determinations
Use membrane filter techniques
for both fecal and total coliform
tests. Only fecal coliform analysis
recommended; do not include total
coliform
It works very well. There are other
more sophisticated chromatographs
which can be used if available.
Sawyer, C. N., and McCarty, P. L. "Chemistry for Sanitary Engineers," McGraw Hill, New York, p. 518 (1967).
155
-------
Parameter
State Water Resources Control Board Cali'irnla (1974)
Method
Rational
PH
Glass electrode
Oxidation-Reduction Pot. Pt and Calomel electrode
Conductivity
Total Solids, Volatile
Leeds & Northrup conductivity
meter
Drying to constant weight
Suspended Solids, Volatile Glass fiber filter
Chemical Oxygen Demand
Total Organic Carbon
Volatile Adds
Tannins, Lignins
Organlc-N
Chlorides
Sulfates
Phosphates
Alkalinity, Acidity
Nitrates
Nitrites
Anmonla-N
Na, K
Ca
Mg
Hardness
Heavy Metals
Biochemical Oxygen Demand
Use of mercuric sulfate to complex
chloride ion
Beckroan 915/215A
Column partition chromatography and
tltratlon
Molybdophosphoric acid
Kjeldahl, tltratlon
Tltratlon with HgNO, using dlphenyl
carbazone indicator
BajSOt precipitation method
Phosphomolybdic acid. Digestion
accomplished by pressure cooking in
autoclave
Tltratlon to equivalence points 5.1;
4.8; 4.5
Brucine method
D1azot1zation with sulfami 1 amide and ,
coupling with alpha naphthylenediamine
EPA method; distilled from borate
buffer at pH 92
Flame photometer and atomic absorption
Ca by precipitation as oxalate and
titration with KHN04. Mg by versene
tltratlon of filtrate. Also AA using La
Ca by precipitation as oxalate and
titration with KMN04. Mg by versene
titration of filtrate. Also AA using La
Calculated from Ca and Mg expressed as
CaC03
AA using heated graphite atomizer and
emission spectroscopy; AA method of
choice
Multiple dilution seeded with
settled sewage
Electrometric pH is most sensitive
method and works well with colored
and turbid solutions. Experience
very satisfactory
Platinum is inert and calomel is a
good reference electrode. Experience
is satisfactory
Experience 1s satisfactory
Satisfactory
Satisfactory
Satisfactory with acidified sample
Satisfactory
Satisfactory
Satisfactory; total N is sum of
ammonia-, organic-.
Gravimetric after acidification
to eliminate carbonates; satisfactory
Satisfactory for total phosphate
Sensitive method. Excludes nitrites
when sulfamic acid is used.
Experience: accuracy and precision
not the best
Minimizes hydrolysis of amino acids;
satisfactory
Satisfactory
Satisfactory
Experience very satisfactory with
reference samples
Strickland, J. 0. H., and Parsons, T. R. "A Practical Handbook of Seawater Analysis" Bulletin by Fisheries Research
Board of Canada, Ottawa (1968) p. 77.
Environmental Protection Agency "Methods for Chemical Analysis of Water and Wastes," EPA-National Environmental
Research Center, Analytical Quality Control Laboratory, Cincinnati, Ohio, Report 16020-07171 (1971).
156
-------
State Water Resources Control Board California (1974)
Parameter Method Rational
Conforms Multiple tube fermentation Leachate precludes efficient
use of membrane filter methods
Total Plate Count Standard Plate Count Satisfactory
Gasses N/A
157
-------
6r1ff1n; Illinois State Geological Survey (1974)
Parameter Method
Rational
PH
Metrohm glass electrode
Oxidation-Reduction Pot. Pt and Calomel electrode
Conductivity
Total Solids, Volatile
Suspended Solids, Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Acids
Tannins, Llgnlns
Organic-N
Chlorides
Sulfste:
Phosphates
Alkalinity, Acidity
Nitrates
Beckman cond. meter
Drying to constant weight
.45 u millipore membrane
Dichromate reflux
Hydroxyl amlne acidic ferric chloride
colorimetric test1
N/A
KJeldahl, tltration
Mercuric nitrate titration -
dlphenylcarboxyl indicator
BaSO« precipitation method
Ascorbic acid
N/A
Brucine method
Gives less drift in leachate then
either Corning or Beckman electrodes.
Meter used 1s not important
Combination Orion 96-78 largest
ft surface area available as a
combustion electrode
Beckman 2,ml pipette cell is less
subject to Interference from the
walls of the vessel and takes less
samples than Yellow Springs
Volumetric finish easy and reliable
Requires small volume of sample
and simple equipment
Faster then electrode titration
Color development is not time
sensitive and determination is more
convenient than SnCl? method
Nitrites
Ammon1a-N
Na, K
Ca, Mg
N/A
Kjeldahl, titration
Atomic absorption, Cs added
Atomic absorption
La added; Sr seemed contaminated
when we tried to use it because it
is so much cheaper than La
'
•
'Montgomery, H. A. C. et al. "The rapid colorimetric determination of organic acids and their salts in sewage
Sludge liquor," Analyst 17, 949 (1962).
158
-------
Griffin; Illinois State Geological Survey (1974)
Parameter Method Rational
Hardness
Heavy Metals Atomic adsorption; N1, Cr, Pb, Atomic Absorption with background
Cd, Zn, Cu, Ag. Fe, Mn, 51, Al, NgO correction for elements below 230
flame, B with methylene blue method Hg by NNA. Questionable high
results with 6 analysis,
carmine method would give better
results.
Biochemical Oxygen Demand N/A
Conforms N/A
Total Plate Count N/A
Gasses
159
-------
Parameter
Ott; Lowell Techn. Institute
Method
Rational
pH
Oxidation-Reduction Pot.
Conductivity
Total Solids, Volatile
Suspended Solids, Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Acids
Tannins, Lignlns
Organlc-N
Chlorides
Sulfates
Phosphates
Alkalinity, Acidity
Nitrates
Nitrites
Ammonla-N
Na, K
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen Demand
Conforms
Total Plate Count
Gasses
Dllalio, R.. and Albertson, 0. E,
Orion Model 701 digital pH meter
N/A
N/A
Drying to constant weight at 105° C,
1 hr at 550° C
N/A
Modification of standard dichromate
method - uses 0.5 N KzC^O; and reflux
for 20 m1n
N/A
Tltration from pH 4 to 71
N/A
N/A
N/A
N/A
N/A
Titration to inflection point of
titratlon curve
N/A
N/A
N/A
N/A
Atomic absorption (Perkin Elmer
Model 107)
N/A
Atomic Absorption (Perkin Elmer
Model 107)
'Unit was available
Time reduction
Unit was available
Unit was available
Seeding/Kinkier DO titration
N/A
N/A
N/A
"Volatile Areas by Direct Titration," JWPCF 33, 356 (1961)
160
-------
Parameter
Pavonl and THtlebaum (1971)
Method
Rational
PH
Oxidation-Reduction Pot.
Conductivity
Total Sol Ids, Volatile
Suspended Solids. Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Acids
Tannins, Llgnlns
Organlc-N
Chlorides
Sulfates
Phosphates
Alkalinity, Acidity
Nitrates
Nitrites
Ammonia-N
Na, K
Glass electrode. Corning Digital III
pH meter
Yellow Spring
Drying to constant weight at 105° C
1 hr at 550° C
Glass fiber filter, constant weight
at 105° C, 1 hr at 550° C
Dlchromate reflux method
Beckman 915 TOC analyzer
Column partition chromatographic method
N/A
Kjt-ldahl. titration
Tltration with electrode
BaS04 precipitation method
Persulfate digestion and SnClz method
Titration to inflection point
N/A
N/A
Itieldahl, titration
N/A
Accepted method
Accepted method
Accepted method
Available equipment
Reliable results obtained
Rapid and accurate at concentrations
less than 10 mg/1
Ease of method with reliable
results
Greatest accuracy and no color
interference
High nitrogen concentrations
Ca, Mg
Hardness
Heavy Metals
Biochemical Oxygen Demand
Conforms
Total Plate Count
Gasses
Atomic absorption
Calculated from concentrations
Atomic absorption
Seeding/no seeding, iodometric-
titration method
N/A
N/A
Greatest accuracy
Greatest accuracy
Greatest accuracy
Confidence in reliability of
method
161
-------
Parameter
Pohland (1974)
Method
Rational
PH
Oxidation-Reduction Pot.
Conductivity
Total Solids, Volatile
Suspended Solids, Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Adds
Tannins, Lignins
Organic-N
Chlorides
Sulfates
Phosphates
Alkalinity, Acidity
Leeds Northrop pH meter model #7411 &
Fisher glass (flow-type) & calomel
electrodes
L & N meter model #7411 & Fisher
platlnium & reference electrode
YSI conductivity meter model 131
Ceramic evaporating dishes
Filtration w/Gellinan glass fiber
filters
Digestion & dichromate - FAS
Beckman M-915 Total Organic Carbon
Analyzer
Hewlett-Packard Model 700-G.C. (w/
Carbowax 4000 60/80 mesh CW Acid
washed-DMCS column)
N/A
Technlcon Autoanalyzer; continuous
Auto digestor & Berthelot colorimetric
reaction
Technicon Autoanalyzer; mercuric thio-
cyanite colorimetric reaction
Atomic Absorption Spectrophotometer
(Perkin Elmer Model 303).
Technlcon Autoanalyzer; molybdate-ANSA
colorimetric reaction
Titration curve w/L & N pH meter glass-
refdrence electrodes & indicators
Good speed; accurate to +^0.1 pH
unit
Stable; accurate m.v. readings
Speed; accurate to + It
Standardized; established results
Standardized; established results
Standardized; established results
Accurate IR readings +_ 1%; limited
by operator's injection technique
Accuracy to 0.5%; trouble free if
tests are performed routinely
Great speed for large number of
samples; +_ 1% accuracy for samples
in 0-100 mg/1 nitrogen range
Great speed for large number of
samples; + 0.5% accuracy for samples
in 0.20 mg/1 Cl range
Excellent speed; accuracy to +
0.05%
Great speed for large number of
samples; +0.5% accuracy for samples
in the 1-50 mg/1.
Accuracy to +_ 2 mg/1 as CaCO,
Nitrates
Nitrites
Ammon1a-N
Na, K
Ca
Mg
Hardness
Heavy Metals
Biochemical Oxygen Demand
Conforms
Total Plate Count
Gasses
Technicon Autoanalyzer; sulfanilamide-
hydrazine colorimetric reaction
Technicon Autoanalyzer; sulfanilimide
hydrazine colorimetric reaction
Technicon Autoanalyzer; berthelot
colorimetric reaction
Atomic Absorption Spectrophotometer
(Perkin-Elmer Model 303)
Atomic Absorption Spectrophotometer
(Perkin-Elmer Model 303)
Atomic Absorption Spectrophotometer
(Perkin-Elmer Model 303)
Chelation; titration w/EDTA
Atomic Absorption; Spectrophotometer
(Perkin-Elmer Model 303)
5-day seeding & Azide modification
of iodometric DO
N/A
N/A
Fisher Gas Partitioner
Great speed for large number of
samples; +_ 0.5% accuracy in 0-1 mg/1
N03~ range
Great speed for large number of
samples; +_ 0.5% accuracy In 0-1
mg/1 NOj" range
Great speed for large number of
samples; +_ 1% accuracy for samples
in 0-100 mg/1 nitrogen range
Excellent speed; accuracy to
+ 0.05%
Excellent speed; accuracy to +
0.05%
Excellent speed; accuracy to +
0.05%
Accuracy to +_ 2 mg/1
Excellent speed; accuracy to + 0.05%
Standardized; established results/
eliminates N2 species interference
Fast, versatile, good separation;
accurate to + 0.5%
162
-------
Parameter
Ralph Stone (1974)
Method
Rational
Oxidation-Reduction Pot.
Conductivity
Total Solids, Volatile
Suspended Solids, Volatile
Chemical Oxygen Demand
Total Organic Carbon
Volatile Adds
Tannins, L1gn1ns
Organic-N
Chlorides
Sulfates
Phosphates
Alkalinity, Acidity
Nitrates
Nitrites
Ammonia-N
Na, K
Ca
Analytical measurements pH meter
N/A
N/A
Drying to constant weight at 105°
C. 1 hr at 550° C
Glass fiber filter, GFC Whatman, constant
weight at 105° C, 1 hr at 550° C
Dichromate reflux
N/A
Column Partition chromatography
N/A
Kjeldahl, tJtration
Mercuric nitrate titration
BaSO. precipitation
Persulfate digestion and SnClj method
Titration to methyl orange
Brucine method
N/A
Kjeldahl, titration
N/A
Either EDTA titration or atomic
absorption, La added
Instrument with limited capabilities,
obtaining a newer Beckman
Messy, but results have been
satisfactory
Hach turfaidimeter
Mg
Hardness
Heavy Metals
Biochemical Oxygen Demand
Conforms
Total Plate Count
Gasses
Either EDTA titration or atomic
absorption, La added
EOTA titration
Atomic absorption
Hach manometric BOD apparatus
MPN multiple tube fermentation
N/A
C02, CH4, 02, N2. Varian A90-P3
GC with Poropak Q and molecular
sieve columns, filament detector
Not as accurate as the standard
method. Results have generally
been satisfactory.
Either 5 or 3 tubes, depending
on the number of samples.
Dehydrated media used
163
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/3-75-011
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
5. REPORT DATE
COMPILATION OF METHODOLOGY USED FOR MEASURING
POLLUTION PARAMETERS OF SANITARY LANDFILL LEACHATE
October 1975 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Edward S. K. Chi an and Foppe B. DeWalle
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORG "VNIZATION NAME AND ADDRESS
Department of Civil Engineering
University of Illinois
Urbana, Illinois 61801
10. PROGRAM ELEMENT NO.
1DB064; ROAP 21BFQ; Task 002
11. CONTRACTKJP»W NO.
CI 68-03-2052
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory
Office of Air, Land, and Water Use
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA-ORD
15. SUPPLEMENTARY NOTES
Project Officer - Richard A. Carnes 513/684-4487
16. ABSTRACT
Different analytical methods can be used to determine a specific parameter, a
preliminary laboratory evaluation was made of those methods least subject to
interferences. All analyses were conducted with a relatively concentrated
leachate sample obtained from a lysimeter filled with milled solid waste. The
results indicate that strong interferences are sometimes encountered when using
colorimetric tests due principally to the color and suspended solids present in
leachate. In such instances alternative methods were evaluated or recommendations
were made to reduce the interfering effects. Automated chemical analysis using
colorimetric methods can sometimes experience significant interferences.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Chemical analysis
Biochemical oxygen demand
Refuse disposal
Leaching
Colorimetric analysis
Chemical composition
/simeters
jthodoloav
Interferences
Solid waste
Parameter
Leachate analysis
13B
13. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
174
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
164
U S. GOVERNMENT PRINTING OFFICE. 1975-657-695/5326 Region No. 5-1 I
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