United States
Environmental Protection
Agency
Environmental Monitoring and
Support Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S4-84-008 Jan. 1984
SEPA Project Summary
Development and Evaluation of
Methods for Total Organic
Halide and Purgeable Organic
Halide in Wastewater
R. M. Riggin, S. V. Lucas, J. Lathouse, G. A. Jungclaus, and A. K. Wensky
Various methods for determining
total purgeable and nonpurgeable
organic halides in wastewater have
been reviewed. Two approaches,
digestion with sodium biphenyl (SBP)
followed by colorimetric detection, and
combustion followed by microcoulo-
metric titration, were selected for
laboratory evaluation. The latter
approach involved the use of a
commercial instrument (Dohrmann
Model DX-20) which had been
designed specifically for the separate
analysis of purgeable organic halide
(POX) and total organic halide (TOX)
using carbon adsorption.
The microcoulometric titration
approach was found to be simpler to
conduct and more precise than the SBP
digestion approach. Surrogate
methods for POX and TOX in water and
extractable organic halide (EOX) in
water and solids were evaluated for a
number of wastewater and solid
samples. The results obtained using the
POX surrogate method generally
agreed within a factor of two with the
results obtained by EPA Method 624
(GC/MS using the purge and trap tech-
nique). TOX results were generally
much higher than results obtained by
solvent extraction-GC methods (EPA
Method 625 and/or 612).
The EOX approach, using the
Dohrmann DX-20, involved significant
modification of the sample inlet system
of the instrument to allow the injection
of 5-25 fjL volumes of solvent directly
into the combustion furnace. Precise
and accurate determination of the
priority pollutant organic halides was
obtained using this approach.
This Project Summary was developed
by EPA's Environmental Monitoring
and Support Laboratory, Cincinnati,
OH, to announce key findings of the
research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
Evaluation of a Method for
Determining TOX in Wastewater
In this phase of the study, the micro-
coulometric titration approach (EPA
Method 450.1) was found to be simpler to
conduct and more precise than the SBP
digestion approach in aqueous and solid
waste samples, and the decision was
made to discontinue efforts on the SBP
approach in favor of the pyrolytic combus-
tion microcoulometric titration approach.
It was concluded, however, that the SBP
approach does appear to be viable and
may be advantageous in certain
situations (e.g., in laboratories where a
microcoulometric system is not available
and the sample load does not justify
purchasing the device). The Dohrmann
DX-20 system was found to be easily
assembled and relatively simple to
operate. The slightly modified Method
450.1 was applied to a variety of waste-
water samples, both spiked and non-
spiked as listed below:
• Reagent water
o Industrial effluent from an aniline
manufacturing facility
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o Two industrial effluents from sepa-
rate chlorinated hydrocarbon manu-
facturing facilities
e An aqueous leachate from a ferrous
chloride spent catalyst waste sample
e POTW sewage from the Columbus,
Ohio plant
For comparative purposes, the values
obtained for POX as well as by solvent
extraction/GC approaches (either EPA
Method 625 or 612) were presented.
In virtually all cases, good recovery
(90% or better) was obtained for the
1,2,4-trichlorobenzene (TCB) spike and
analytical precision was generally 5-10%
relative standard deviation (RSD). Further
inspection of the data revealed that the
TOX values were considerably greater
than the combined POX and "extractable
OX" values, and indicatedthatpolar, non-
extractable materials such as chlorinated
humic acids were contributing to the TOX
values.
A limited study was conducted to
assess the feasibility of using the Dohr-
mann DX-20 system to determine the
EOX content of water samples. The
Dohrmann DX-20 system was modified
by replacing the boat entry system with a
Teflon-lined silicone septum held in place
with a ball and socket glass fitting
(supplied).
The method involved extraction of a
one-liter sample aliquot with three 60-
mL aliquots of cyclohexane, concentra-
tion of the extract by Kuderna Danish (K-
D) concentration to 1 mL and injection of
a 25 fjL aliquot of the extract. Recoveries
were acceptable (>70%) in all cases,
indicating that this approach can be used
successfully to determine EOX content of
water samples. .The surrogate TOX
method for wastewaters was presented
in the appendix of the report.
Determination of EOX Content
of Solids
The development of a method for
determining EOX in solids was consid-
ered to be necessary because of the need
to isolate and analyze separately the
suspended solids in wastewater samples
being analyzed by EPA Method 450.1.
The approach selected was to extract the
solid residue with a polar organic solvent
(ethyl acetate) and to analyze the extract
using the Dohrmann DX-20 microcoulo-
metric system, modified for solvent injec-
tion. The EOX procedure was evaluated
using the solid samples described below:
« A garden soil which had been air-
dried and passed through a 30-mesh
sieve
0 Wet solids (47% solids) isolated from
the aniline wastewater
e Wet solid waste (64% solids)
obtained from a solid waste landfill
• Ferrous chloride spent catalyst
waste (85% solids) from a
chloroethylene manufacturing plant
• Drying and solid waste (50% solids)
from a chloroethylene manufactur-
ing plant
The solids were spiked with methanol
stock solutions of TCB, trichloroanaline
(TCA) or trichlorophenol (TCP) at various
levels. TCB was recovered from all solids
samples at the 25 /jg/g spike level better
than 80%. TCA and TCP showed only
about 50% recovery at the 25 fjg/g
spike level.
Removal of potential interferences by
inorganic chloride was also investigated.
Washing the ethyl acetate extract with
one mL of 1 M Ag NOa solution was
effective in removing virtually all of the
inorganic chloride.
In order to assess the detection limit of
the method, seven replicates of a process
blank and a 15 //g/g (TCB as CL) process
spike were analyzed on the Dohrmann
DX-20. The data obtained indicated that
the method can detect approximately 10
/yg/g of EOX.
Based on these data, the EOX/solids
surrogate method appears to work quite
well. However, because of the larger
diversity of solid-sample type, this
method should not be assumed to be
accurate for uncharacterized samples
without further validation. The surrogate
method for EOX in solids was presented
in the report's appendix.
Determination of POX in
Water Samples
This phase of the study involved the use
of the Dohrmann DX-20 system
equipment with a special purging device.
The sample preparation and workshop
steps were essentially identical to those
specified in EPA Method 624. For POX
analysis, a 10-mL or smaller aliquot of
water sample is placed in the purge
device and a stream of CO2 is passed
through the purge tube. The purged
components enter the combustion tube
(held at 800°C) and are converted to the
corresponding hydrogen halides.
Initial experiments to evaluate the
recovery of the organohalide priority pol-
lutants from reagent water revealed
recoveries of 75% or greater for olefimic
and ''alphatic chlorine-containing
compounds and recoveries of
approximately 50% for the chloroaromat-
ics and bromine-containing compounds.
Relative standard deviations were 10% or
less in all cases indicating that the system
was operating at good precision in spite of
the low recoveries obtained.
Wastewater samples on which the
method was evaluated are listed below:
« Columbus tap water
e Columbus POTW final effluent
* A final effluent from a plant
producing analine and related
compounds
e Two final effluent samples from sep-
arate plants producing chlorinated
hydrocarbon solvents (treated by
steam stripping prior to discharge)
e An aqueous leachate from a spent
FeCLj catalyst solid waste (chloro-
ethylene manufacturing)
« A wastewater from a chemical man-
facturing plant in'which methylene
chloride is used as a solvent
Results and Conclusions
Results of the analysis for the various
water samples using the surrogate POX
method were compared with results from
analyses by EPA Method 624. The results
obtained agreed quite well (within a
factor of two) in most cases. Based on the
results obtained in this study, it appears
that the surrogate POX method can be
used as an indicator of organic halide
pollution in a variety of water types.
However, several limitations of the
method should be recognized. First, the
recovery of purgeable organic halides is
seldom greater than 85-90% and can be
as low as 40-50%. Secondly, the recovery
of brominated species is not quantitation
and, at least in the case of bromoform,
levels of less than 100 /yg/L cannot be
quantified. The POX value obtained in an
uncharacterized water sample will vary
considerably depending on the properties
of compounds present (e.g., bromine vs
chlorine, percent halogen, purging
efficiency, etc.). In view of these
uncontrollable factors, the agreement
between GC/MS and the surrogate POX
was considered to be satisfactory.
In order to assess the low limit of detec-
tion of the surrogate POX method, several
compounds were run according to the
EPA/EMSL protocol for determining
method detection limits (MDL). MDL's of
2-5 A
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The surrogate POX method for
| wastewaters was presented in the
report's appendix.
R. M. Riggin. S. V. Lucas, J. Lathouse, G. A. Jungclaus, and A. K. Wensky are
with Batte/le-Columbus Laboratories. Columbus, OH 43201.
Stephen Billets is the EPA Project Officer (see below).
The complete report, entitled "Development and Evaluation of Methods for Total
Organic Halide and Purgeable Organic Halide in Wastewater," fOrder No. PB
84-134 337; Cost: $14.50, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield. VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Monitoring and Support Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
«U.S. GOVERNMENT PRINTING OFFICE: 1984-759-015/7292
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