United States
Environmental Protection
Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S2-86/112 March 1987
Project Summary
PCB Sediment
Decontamination—
Technical/Economic
Assessment of Selected
Alternative Treatments
Ben H. Carpenter
U.S. Environmental Protection Agency
Re-ion 5, Library (5PL-16)
?.K) S. Dearborn Street, Room 1670
Chicago, IL 60604
Eleven emerging alternative treat-
ments for Polychlorinated Biphenyl
(PCB) contaminated sediments have
been compared and ranked using tech-
nical performance, status of develop-
ment, test and evaluation data needs,
and cost as factors. In ranking the proc-
esses, weights were assigned to the
factors to emphasize the extent of de-
contamination, the estimated cost of
treatment, and the versatility of the
process.
The emerging treatment processes
are based on six different technologies:
one on low-temperature oxidation, two
on chlorine removal, one on pyrolysis,
three on removing and concentrating,
one on vitrification, and three on mi-
croorganisms. Types of technologies
not developed are chlorinolysis, stabi-
lization, and enzymes.
On the basis of the comparisons
made, the treatment processes were
ranked in the following order from
highest to lowest: KPEG, LARC, Acurex,
Bio-Clean, Supercritical Water, Ad-
vanced Electric Reactor, Vitrification,
OHM Extraction, Soilex, Composting,
and Sybron Bi-Chem 1006. The first
eight processes show potential for re-
duction of PCB concentrations to the
desired background levels (1 to 5 ppm)
or less, with minimum environmental
impacts and low to moderate cost. All
the technologies except the advanced
electric reactor required further devel-
opment and testing.
This Project Summary was devel-
oped by EPA's Hazardous Waste Engi-
neering Research Laboratory, Cincin-
nati, OH, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering infor-
mation at back).
Introduction
The PCB contamination problems in
the Hudson River and New Bedford,
Massachusetts are reported to be
among the worst in the United States in
terms of concentration and total
quantity of PCBs. It is estimated that
290,000 kg of PCBs are contaminating
382,000 m3 (500,000 yd3) of sediments
in identified "hot spots" of the Hudson
River. During the 70s, approximately
907,000 kg of PCBs were used in the
New Bedford area annually, of which an
estimated 45,500 kg were improperly
disposed. There are also numerous in-
dustrial lagoons contaminated with
large quantities of PCBs. The PCB con-
tamination problems pose threats to
both drinking water and the fishing in-
dustry.
The only available proven technology
is dredging and incineration. Land dis-
posal of the sediments untreated has
legal restrictions. Biodegradation is a
possibility, but sufficient information
does not exist to design and operate
such a system. There is little experience
in the application of encapsulation tech-
nology to PCB-contaminated sedi-
ments.
This study was undertaken to identify
the most technically feasible processes
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that have been proposed by research
concerns for the removal of PCBs from
sediments; to identify their extent of de-
velopment, effectiveness, limitations
and probable costs; and to determine
needs for further development. The
study involved four phases: data acqui-
sition, screening and selection of the
most technically feasible processes, de-
velopment of critieria for process as-
sessment, and process assessment.
Data Acquisition
Three major source of data were:
EPA's file of proposals and correspon-
dence concerning problems of PCB con-
tamination and possible approaches to
alternative solutions; the open litera-
ture; and direct contacts with propo-
nents of treatment technologies.
A bibliography (171 references) was
prepared, which included treatment fea-
sibility study reports, process test and
evaluation reports, process develop-
ment proposals, and patents. As proc-
esses were identified, direct contacts
were made with the investigators for
details of their process studies.
Screening and Selection of
Most Technically Feasible
Processes
Alternative destruction/detoxifica-
tion/removal (DDR) processes were
subjected to screening to identify those
to be assessed further. The processes
were categorized according to their
generic technology so that their poten-
tial performance could be judged ap-
propriately. Processes with undesirable
aspects were rejected from further as-
sessment. For example, lack of toler-
ance for water by a process is undesir-
able because extensive sediment drying
is required. Processes showing insuffi-
cient tolerance for water were therefore
rejected from further consideration as a
primary treatment process in favor of
more tolerant alternatives.
Table 1 lists the processes screened,
identifies those selected for further as-
sessment and gives the reasons for re-
jection of the rest. Some of the tech-
nologies (e.g., nucleophilic substitution)
have provided several processes. Some
(e.g., enzymes) have not yet provided
any processes. A process evaluated as
"1" in Table 1 was selected for further
assessment. Other evaluation numbers
assigned to the rest of the screened
processes refer to footnotes that iden-
tify the reason for rejection of the proc-
ess for further assessment. References
cited are identified fully in the bibliogra-
phy of the full report.
Development of Criteria for
Process Assessment
The PCB contamination problem in
the Hudson River is representative of
the type of PCB destruction/detoxifica-
tion problems focused on in this study.
It is expected that the contaminated
sediments will have to be dredged from
all sites and that the dredged sediments
will have high water content.
Criteria for assessment of alternative
treatments were chosen which relate to
a broad range of principles of operation
of diverse applied technologies, yet can
be used effectively in comparing one
treatment process with another. Addi-
tional factors, specific to a technology,
were included to help portray the inher-
ent strengths and limitations of a proc-
ess. Table 2 lists the seven criteria used
in comparative process evaluation and
three additional factors relating to the
needs for further process development
and evaluation. The table also includes
an overall description of the findings for
the processes evaluated.
The goal set for process performance
is to reduce the PCB concentration in
treated sediments to background levels
of 1 to 5 ppm. Several of the processes
were found to meet this goal. Those that
showed reduction to less than 2 ppm
were assigned a rating of "6". Those
that attained a level between 2 and 10
ppm were assigned a "4". Those with
residual concentrations greater than 10
ppm were rated "2".
Available capacity was found not to
exist for any of the processes. However,
several were developed sufficiently to
permit projections of the time required
to build a facility for application of the
treatment. Those for which such projec-
tions could not be made were rated "2".
Those requiring 24 or more months
were rated "4". Those requiring 12 to 16
months were rated "6".
Conditions/limitations that were rated
were tolerance for water, required proc-
essing time, and controllability of proc-
ess conditions. Those treatments that
could tolerate water up to about 40 per-
cent would not require a drying step
with its attendant fines' control prob-
lems. Those requiring only 1 day for
treatment could generally show a faster
rate of cleanup than those requiring
3 days. Some biological processes re-
quired more than 3 weeks. The treat-
ments generally provided control of the
processing conditions; however, a fev
(e.g., composting) would not necessai
ily do so. The three conditions/limite
tions were ranked as follows:
Conditions/limitations
Ran
Tolerates to 40 percent water 6
and treats in 1 day
Sediment needs to be dried 5
Tolerates to 40 percent water 4
and treats in 3 days
Tolerates water and treats in 3
>3 weeks
Sediment needs to be dried, 2
treats in >3 weeks
Processing conditions uncon- 1
trollable
Concentration range handled in data
developed for the processes ranged
from unknown to 3,000 ppm. Ratings
were assigned based on the upper limit
of feed concentration. The ratings were
as follows:
PCB concentration treated, ppm Rank
s=3,000
2,000 to 3,000
1,500 to 2,000
500
250 to 350
Unknown
6
5
4
3
2
1
Status of development ratings were
"1" for no data, "2" for laboratory-scale
tests completed, "3" for bench-scale
tests completed, "4" for pilot-scale tests
completed, "5" for field tests com-
pleted; and "6" for commercial system
designed and ready for construction.
Test and evaluation data needs could
be rated differently, depending upon
the purpose. For indicating the extent to
which a treatment process is readied for
use, the more data that are available the
better. For indicating the need to sup-
port a very promising technology that
lacks sufficient progress, the potential
and the data needs should be rated in
combination. The ratings used here are
for the former purpose and are as fol-
lows:
Test and evaluation data needs Rank
None except permits and 6
checkout
Field tests 5
Pilot tests and costs 4
Laboratory and bench tests 3
Conceptual treatment process 2
design
D/D/R data, residual PCB data, 1
RCRA waste data ^
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Table 1. Screening of PCS Treatment Processes
Generic technology References
Process
Evaluation3
Chemical
Low-temperature oxidation
Wet air oxidation
Supercritical water oxidation
Chemical oxidants
Ozonation
Chlorine removal
Deri ydrochlorination
Reducing agents
Nucleophilic substitution
Radiant energy
Electromechanical reduction
Chlorinolysis
Pyrolysis
Centofanti 1971; Chen 1982; Childs 1982; Crad-
dock 1982; Edwards et al. 1982; Environment
Canada 1983; Hornig 1984; Massey and Walsh
1985; Rogers and Kornel 1985; Rogers 1983;
Rogers 1985.
Baillod et al. 1978; Miller and Sevientoniewski
(n.d.); Miller and Fox 1982.
Modelletal. 1982.
FMC Corporation (n.d.); March 1968.
Arisman et al. 1981; Lacy and Rice Deschlaeger
1976; Prengle and Mauk 1978.
U.S.P. 346, 636
Chu and Vick 1985; Lapiere et al. 1977.
Chu and Vick 1985; Sworzen and Ackerman 1982.
Brown et al. 1985a; Brunelle and Singleton 1985;
March 1968; New York University 1984; Ruzz et
al. 1985; Smith and Gurbacham 1981; Sunohio
(n.d.); Sweeney and Fischer 1970; United States
Patent Office 1984b; Weitzman 1984; Weitzman
1984; Weitzman 1985.
Bailin and Hertzler 1977; Bailin and Hertzler
1978; Bailin et al. 1978; Craft et al. 1975; Dev et
al. 1985; Kalmaz et al. 1981; Meuser and Weimer
1982; Plimmer 1978; Rogers and Kornel 1985;
Rogers 1985; Trump et al. 1979; West et al. 1983.
Massey and Walsh 1985.
Sworzen and Ackerman 1982.
Boyd 1985; New York State Department of Envi-
ronmental Conservation 1985a; New York State
Department of Environmental Conservation
1985b.
Uncatalyzed, general 2
Zimpro Process, Santa Maria, CA 4, 13
Waste Site
Catalyzed
Dow Chemical Co. Patent 3,984,311 2
IT Environmental Science 2
Modar 1
Potassium permanganate plus 6
Chromic Acid and Nitric Acid
Chloroiodides 4, 7
Ruthenium tetroxide 3, 4, 8
GE UV/ozonation process 2
Molten aluminum/distillation 14
Catalytic: 2,3
Nickel on kieselguhr 2, 3
Pd on charcoal 2, 3
Lithium aluminum hydride 2, 3
Butyl lithium 2, 3
Raney Nickel 2, 3
Sodium in liquid ammonia 7, 9
Nickel-catalyzed zinc reduction 7, 9
Hydrazine 7, 9
UV light plus hydrogen 2
Mildly acidic zinc powder, Sweeney 2, 14
and Fischer (1970)
Sodium-based processes;
Goodyear, sodium in naphthalene 10
(1980)
Acurex, proprietary solvent 10
PCBX/Sun Ohio 10
PPM 10
Ontario Hydro Power 10
Potassium poly (ethylene glycolate)
based:
EPA In-house KPEG 1
KPEG Terraclean-CI 1
GE KOH-PEG 11
New York University KPEG 12
UV/photolysis 3
Syntex photolytic 3, 4
Thermal corona glow 5
Microwave plasma 9, 17
RF insitu heating 18
Gamma radiation (Craft et al. 1975) 9
LARC 1
Electromechanical research process 14
Hoechst process 9
Goodyear catalytic hydrogenolysis 9
Exhaustive chlorination 9
Advanced Electric Reactor 1
Wright-Malta alkaline catalyst fuel-gas 12
process
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Table 1. (Continued)
Generic technology
References
Process
Evaluatioi
Physical
Removing and concentrating
Heated Air Stripping
Extraction
Adsorption
Vitrification
Stabilizing
Bottom recovery
Biological
Microorganisms
Angiola and Soden 1982; Caron 1985; Gilmer
and Freestone 1978; Githens 1984; Hancher et al.
1984; Hawthorne 1982; Lee et al. 1979; Saunders
1985; Schwinn et al. 1984; Versar, Inc. 1984.
Enzymes
Timmerman 1985.
Ghassemi and Ham 1985; Law Engineering Test-
ing Company 1982; Stroud et al. 1978; Subnama-
nian and Mahalingam 1977; Tittlebaum et al.
1985.
Carich and Tofflemire 1983; Hand and Ford 1978;
Murakami and Takeishi 1978; U.S. Army Corps of
Engineers Water Resources Support Center 1983;
Zimmie and Tofflemire 1978.
Bedard et al. 1985; Bumpus et al. 1985; Clark et
al. 1979; Dawes and Sutherland 1976; Furakawa
1982; Isbister et al. 1984; Kong and Sayler 1983;
McCormick 1985.
New York State Department of Environmental
Conservation 1985a; New York State Department
of Environmental Conservation 1985b; Rhee et
al. 1985b; Rhee et al. 1985; Unterman et al. 1985.
Catelani et al. 1971; Rochkind et al. Unterman et
al. 1985
American Toxics Disposal, Inc.
Critical Fluid Systems, CO2
Furfural
Acurex solvent wash
O.H.M. extraction
Soilex process
Carbon adsorption, general
Neoprene rubber adsorption
Battelle vitrification process
Asphalt with lime pretreatment
Z-lmpremix
Sulfur-asphalt blends (K-20)
Ground freezing
Dredging
Bio-Clean
Sybron Bi-Chem 1006 PB
Composting
Bio-Surf
Ecolotrol, Inc.
Wormes Biochemical's Phenoback
Rhee anaerobic degradation
No processes found
14
14
15
1
1
1
13
15
16
15
16
13
13
1
1
1
4, 13
4, 13
11, 13
14
3Explanation of process rating:
1. Identified emerging sediment treatment process.
2 Destruction efficiency appears to be too low to meet environmental goals.
3 Processing time appears to be extremely long for practical timely cleanup.
4 Data available for dioxin, other chlorinated compounds, or other contaminants, but not PCB's.
5. Process has been shown to destroy PCB's in gas streams only. It may be feasible for sediments, but has not been shown to be.
6. PCB's with 5-7 chlorine atoms per molecule are not destroyed.
7. Products of partial degradation may be toxic.
8. Reagent is very costly/toxic or both.
9. Process costs appear to be excessively high compared with other emerging treatment processes.
10. Water destroys the reagent or interferes with its action, thus the process would require excessive drying of sediments and, probably,
extraction in pretreatments. The process would therefore have application only as a subordinate final step to several extraction and
concentration operations
11. This particular process was not evaluated because data were not available for assessment.
12 This process is an alternative to another process using the same generic tehnology, but it is in very early stages of development, and
data were not available for assessment.
13. This technique is basically applicable to preliminary operations prior to treatment or to treatment of wastestreams (e.g., wastewaters)
from chemical or physical treatments.
74. friis process is in the concept stage and data are insufficient to assess it for PCB-contaminated sediments.
15. This process has been found to be ineffective.
16. This technology provides only for encapsulation of the PCB-contaminated sediments.
17. This process supports incineration of PCB's.
18. The process does not appear to be feasible for submerged sediments.
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Table 2. Criteria and Technical Factors Used in Process Assessment
Criteria/Factor
Description
Criteria
Estimated Residual PCB
Available Capacity
Conditions/Limitations
Concentration Range Handled
Status of Development
Test and Evaluation Data
Needs
Estimated Cost
Factor
Unit Operations
RCRA Waste Generated
Estimated D/D/R Efficiency
The goal set for process performance was to reduce the PCB concentration in treated sediments to
background levels of 1 to 5 ppm. Several of the processes were found to meet this goal.
Although available capacity was found not to exist for any of the processes, several were developed
sufficiently to permit projections of the time required to build a facility for application of the treat-
ment.
These include tolerance for water, required processing time, controllability, extent of destruction/de-
contamination, number of stages of extraction required, and limits on the concentration of PCBs
that could be treated. Some processes required one day or less for cleanup; some biological proc-
esses required more than 3 weeks.
The PCB concentration of the sediments treated ranged from unknown to 3000 ppm. Some proc-
esses had limits inherent in the technology.
Processes were found to range from concept stage to completed field test stage. Most were in the
pilot stage of testing.
Data needs varied with the status of the process development. At worst, data were available show-
ing tests of the concept. At best, the process had been field tested, and only permits and checkout
were needed.
The estimated costs of treatments were made in terms of the cost per cubic meter of dry sediment
treated, assuming a density of 1.68 Mg/m3, plus costs of associated operations-dredging, trans-
portation, handling of treated sediments, as required. All costs are stated in 1985 dollars.
The process technology was described, including the active agents, the principles and mechanisms
of PCB destruction, and complete characterization of all unit operations.
Some processes have hazardous wastes as residuals from the treatments applied.
All the processes achieved a better than 90% destruction/detoxification/removal (D/D/R) efficiency.
The application of any treatment
process can involve the need for one or
more of the following unit operations:
dredging, transport, storage, landfill
disposal, land treatment disposal, incin-
eration, and/or alternative treatment.
Estimates were developed for all of
these so that, in any given process eval-
uation, the proper elements could be
added to obtain an estimate of the cost
of application. The estimates were
made in terms of the cost per cubic
meter of sediment treated. The sedi-
ment was assumed to have a density of
1.68 Mg/m3.
Dredging costs for those treatments
requiring removal of the sediment be-
fore treatment are estimated at $20/m3
based on the recent experience of the
U.S. Army Corps of Engineers in con-
tracting for dredging in the New York
State area.
Transport costs are given as a range.
The Corps' experience is $13/m3 for
lort hauling distances. A cost of $126/
m3 was used for long hauling distances,
which represents an assumed 483-km
average transport distance to RCRA
landfills capable of accepting PCB-
contaminated wastes.
Storage cost will sometimes be in-
curred to hold the dredged sediments
pending treatment; e.g., where dredg-
ing rates exceed the rates at which the
treatment can be applied. These have
been set arbitrarily at $10/m3.
Land treatment involves the con-
trolled application of wastes to the sur-
face of the soil. At land-treatment facili-
ties, wastes are either spread on or
injected into the soil, followed by tilling
into the soil with farm equipment. The
physical and chemical properties of the
soil, in unison with the biological com-
ponent of the soil and sunlight work to-
gether to immobilize, degrade, and
transform portions of the wastes. The
application and tilling process can be
repeated many times on the same plot,
making land treatment a dynamic sys-
tem designed to reduce and ultimately
eliminate a portion of the waste, as op-
posed to permanent storage such as
landfills.
The American Petroleum Institute in
1983 reported that there were 213 land-
treatment facilities in operation han-
dling waste from 16 different industry
sectors. The most extensive use of land
treatment is for petroleum refinery
wastes, with 105 land-treatment facili-
ties, many of which are located on the
same site as the refinery. More recently,
EPA verified the existence of 114 land-
treatment facilities and obtained infor-
mation on operating parameters at
some of these sites.
Wastes are typically mixed to a depth
of 0.5 to 1.0 feet, where biochemical re-
actions take place. Application frequen-
cies can range from daily to yearly, with
tilling occurring as frequently as daily.
The average cost of controlled, man-
aged land treatment cited by the Ameri-
can Petroleum Institute, $60/ton,
-------
equates to $111/m3 of sediments. For
short-term land treatment of readily-
degradable solvents remaining in
treated sediments free of PCBs after
they are washed or dried, the cost is
estimated at $33/m3.
Redeposition costs of decontami-
nated sediments were also estimated at
$33/m3. Slightly lower costs might be
expected in special cases.
Because the regulations permit the
use of incineration or chemical waste
landfill and the application costs of
these two methods are available from
firms engaging in their practice, these
costs were used as lower and upper lim-
its with which to compare the costs of
applying new alternative technology.
Landfill disposal costs, incurred when
the sediments must be placed in author-
ized chemical waste landfills, are esti-
mated as ranging from $260/m3 for the
Michigan area (EPA Regional Office) to
$490/m3, based on the highest prices
charged for hazardous wastes by com-
mercial facilities. This range includes an
intermediate value reported by the
Corps of Engineers: $420/m3.
Costs for incineration techniques ca-
pable of achieving 99.9999 percent de-
struction and removal efficiencies for
PCBs are difficult to predict. Even more
difficult is prediction of the price com-
mercial facilities will charge to accept
the responsibility of handling such a
sensitive waste. Surveys made to deter-
mine the likely charges to incinerate
dioxin-containing wastes resulted in a
reported price on the order of $1,0007
Mg. This translates to $1,680/m3, the
value adopted for this evaluation, and
the cost of disposal of residue from in-
cineration is included. The total cost of
use of incineration including dredging
at $20/m3 and transport at $13 to $126/
m3 is$1713to$1826/m3.
When available, alternative treatment
costs were obtained from the propo-
nent of the process. Otherwise, they
were estimated based on the types of
unit processes involved and the envi-
ronmental controls required, or they
were determined not to be estimable
considering the status of development
of the process.
While all costs are in 1985 dollars, the
treatment costs are not all necessarily
based upon the same labor rates, corpo-
rate fixed charges, or profit. These costs
vary from one firm to another. The cited
estimates are costs of purchasing the
treatments. Further cost analyses will
be needed to provide a basis for com-
parison of processes on the basis of in-
dividual cost elements.
Table 3 shows the unit cost estimates
used to develop cost ranges for the
emerging treatments.
Estimated costs were rated by com-
paring the range of the cost estimates
obtained with the cost of placing them
into a chemical waste landfill. Treat-
ment processes showing the lowest es-
timated cost range were rated "6";
those showing a probable cost lower
than landfill were rated "4"; those
showing an estimated cost equal to
landfill were rated "2"; and those show-
ing an estimated cost range greater
than landfill were rated "1".
Overall ranking was accomplished
through the use of weighting factors as-
signed to each rated factor. The
weighted average rank was then ob-
tained by summing the products of the
weighting factors and the ratings and
dividing by the sum of the weighting
factors. The weighting factors were:
Factor
Weight
Residual PCS concentration 5
Capacity 2
Conditions/limitations 3
Concentration range handled 2
Status of development 2
Test and evaluation data needs 1
Estimated costs 4
The weightings tend to give greatest
emphasis to the ability of the treatment
to reduce the PCBs and to the probable
Factor level
Table 3. Unit Costs Estimates for Steps
Involved in Treatment and
Disposal of PCB-Contaminated
Sediments
Operation
Dredging
Transport
Storage
Landfill and Disposal
Landfarming
Restricted Land Disposal
Incineration
Cost, $/m:
20
13 to 126
10
260 to 490
33
111
1680
cost of the treatment. Much less empha-
sis is placed on the status of develop-
ment. Thus, an almost fully developed
process with an extremely high cost
would be ranked lower by application of
the weighting process than a less devel-
oped process with a much lower poten-
tial cost. Test and evaluation data needs
have not been heavily weighted be-
cause nearly all the alternative treat-
ment processes that show low potential
cost require more data to be proven.
Under this procedure, the perfect
process for treating PCB-decontami-
nated sediments would show the fol-
lowing levels for each ranking factor
and would receive, using the ratings
given, a weighted rating of 6.0:
Rating, R
Wt
R x Wt
1.
2.
3.
4.
5.
6.
7.
Residual PCB, treated sediment
less than 1 ppm
Capacity adequate for site
cleanup available in 12-16 mo.
Tolerates to 40 percent water
and treats in 1 day (24 hr)
Handles concentrations greater
than 3,000 ppm
Commercial system designed
and ready for construction
No test and evaluation data
needs except permits and
checkout
Lowest estimate cost range
among alternative emerging
technologies
6
6
6
6
6
6
6
5
2
3
2
2
1
4
30
12
18
12
12
6
24
Total R x Wt 2R x Wt
Weighted rating(2R x Wt)/2Wt
114
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Process Assessment
The processes were assessed by
characterization and ranking. Character-
ization provided for objective compari-
son of the processes. Ranking provided
a subjective comparison of the proc-
esses based on the seven criteria.
Characterization
Table 4 summarizes five characteris-
tics of the processes: unit operations,
available capacity, conditions/limita-
tions, concentration handled, and any
generated RCRA wastes. The unit oper-
ations employed are given, and each is
identified by a number. Generally, a
greater number of unit operations will
mean a greater effect on treatment
costs.
None of the processes has currently
available capacity approaching that re-
quired for major cleanups. Therefore,
the time required to build capacity is
listed. Construction time ranges from 12
to 24 months.
Certain conditions that typify the
process or limit its versatility are given
in column 4 of Table 4. Table 4 also
identifies any RCRA waste streams gen-
erated by the process.
The data from studies of the proc-
esses were examined for ranges of PCB
concentrations handled to date. Gener-
ally, the values are not limitations on
the process, but only on the data ac-
quired. The value =s300 ppm for the Bio-
Clean process may, however, be a limi-
tation requiring process adjustment to
control.
Table 5 lists five additional character-
istics of the processes and the rating de-
veloped in the ranking process. The
characteristics shown here relate to the
needs for further process development
and evaluation. The process status is
given in terms of stages of development
completed. The processes range in
stages completed from concept to pilot
plant.
Both PCB destruction and residual
PCB concentration in treated sediments
are given to the extent available. Certain
processes may require extension of the
unit operations employed (e.g., more
stages of extraction) to attain the re-
quired performance levels.
Test and evaluation data needs are in-
dicated for each process. Needs vary
from one (Advanced Electric Reactor
process) to complete site-specific evalu-
ation.
The estimated costs of applying the
ocess are listed in $/m3. Although cost
estimates lack the necessary accuracy
at this stage of development of the alter-
native processes to serve as the sole
criterion of potential, they nevertheless
indicate that seven of the processes
may cost no more than landfill and five
could cost less. (Cost estimates could
not be made for the Sybron process and
composting.)
Ranking of Treatment
Processes
In contrast to process characterization
which involves all factors listed in Ta-
bles 4 and 5, ranking is subjective and is
based on the seven criteria previously
described. An attempt was made to de-
fine and determine a single number that
could represent the overall position of
each process relative to an arbitrarily
defined perfect process.
Based on the weighted ratings, the
processes rank as follows from highest
to lowest: KPEG, LARC, Acurex, Bio-
Clean, Modar-Supercritical Water, Ad-
vanced Electric Reactor, Vitrification,
OHM Extraction, Soilex, Composting,
and Sybron Bi-Chem 1006 PB/Hudson
River Isolates.
Conclusions
Emerging treatment processes for de-
contamination of sediments containing
PCBs that show potential as alternatives
to incineration and chemical waste
landfill have been identified. Eleven al-
ternative treatments were compared
and ranked using technical perform-
ance, status of development, test and
evaluation data needs, and cost as fac-
tors. The first eight processes show po-
tential for reduction of PCB concentra-
tions to the desired background levels
(1-5 ppm) or less, with minimum envi-
ronmental impacts and low to moderate
cost. The sediments must be dredged
for application of these treatments.
Of the 11 processes assessed, all but
the Advanced Electric Reactor (AER) are
in various stages of development from
laboratory-scale through field tests. The
AER is a permitted treatment under
TSCA in EPA Region VI, based on com-
pleted trial burns. There is no immedi-
ately available capacity for any of the
treatment processes. Further data are
needed in most cases to define the final
system designs for the processes.
At this stage, estimated costs of appli-
cation of these 11 processes are less
than or within the range of costs of
chemical waste landfill, except for the
AER estimated cost, which exceeds that
of landfill, but is less than incineration.
These costs are planning estimates
only. In most cases, further research is
needed to provide data suitable for
more definite cost estimates.
The emerging treatment processes
are based on six types of generic tech-
nologies: low-temperature oxidation,
chlorine removal, pyrolysis, removal
and concentration, vitrification (melt-
ing), and microorganisms. Types of
generic technologies not yielding com-
petitive emerging processes are: chlori-
nolysis, stabilization, and enzymes. A
search of these technologies yielded no
suitable candidate processes at this
time.
On the basis of the comparisons
made, the treatment processes were
ranked in the following order from
highest to lowest. The estimated cost
range (1985 dollars) per cubic meter of
sediment treated is also shown for each
process. Costs of chemical waste land-
fill and incineration are given for com-
parison.
KPEG
LARC
Acurex Solvent Wash
Bio-Clean
Modar Supercritical Water
Advanced Electric Reactor
Vitrification
OHM Methanol Extraction
Soilex Solvent Extraction
Composting
Sybron Bi-Chem 1006
Chemical Waste Landfill
Incineration
$211-378
$223-336
$196-569
$191-370
$250-733
$830-942
$255-548
$400-514
$856-913
Unable to
estimate
cost
Unable to
estimate
cost
$260-490
$1713-1826
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Table 4. Treatment Process
Process
Chemical
Supercritical water oxidation
KPEG, Terraclean-CL
KPEG, NYU
KPEG, EPA in-house
LARC
Advanced electric reactor
(I.M. Huber)
Physical
0. H. Materials methanol ex-
traction
"Soilex" kerosene/water
Acurex solvent wash
Vitrification
Biological
Composting
Bio-Clean
Sybron Bi-Chem 1006
Assessment
Unit
operations
1,4,10
1,3,4,7
1,2,3,4,5,6,7,9
Fundamental studies
1,2,5, 15
7,8, 12, 13, 14
2,7,8,14,15
1,2,5, 15
2,4,5,6, 10, 1 1
8, 12, 14
15,16
1,2,17
15,17
Available
capacity (or
time to provide) Conditions and limits
20-40% solids; 374°C,
23.3 MPa organic content
>5% or supplemental
fuel
(24 mo) 150 °C, 0.5-2 h
(24 mo) tolerates 25% water.
(16 mo) 2204°C, 2,400 kWh/m3
needs predryer
predry to <1% moisture
25% of kerosene solvent
retained in soil; 3 d per
batch
3- 12 washes, tolerates
<40% water.
Electrical power usage
increases with soil mois-
ture; submerged sedi-
ments dredged and
treated
(16 mo) Seasonal effects, reaction
time must be >4 weeks
27 m3/d available, Proved for POP, labora-
12 mo for full-size tory confirmed for PCS's
Unknown
Concentration
handled
>3000 ppm
500 ppm or
greater
480 ppm
>3000 ppm
>400 ppm
to 350 ppm
tested
up to 1,983
ppm
500 ppm
1,590 ppm
s300 ppm
Unknown
RCRA
waste
generated
None
vv.vv.tr. act.
carbon
None
None
PCB-loaded
carbon from
solvent
cleanup
Concentrated
PCB from
still to incin-
eration
Concentrated
PCB's to
KPEG
None
Treated ma-
terial is still
a RCRA
waste
None
Unknown
NOTE—Unit operations key:
1. Liquid/solids separation
2. Extraction/solubilization (liquid-solids)
3. Liquid/liquid extraction
4. Chemical reactor
5. Stripping still
6. Solvent recovery still
7. Adsorption
8. Dryer (solids)
9. Dryer (liquids)
10. Filtration
11. Steam cleaning
12. Thermal reactor
13. Grinding
14. Air pollution controls
15. Landfarm
16. Innoculation/digestion
17. UV light reactor
-------
Table S. Treatment Process Assessment
Process Status"
Chemical/physical
Supercritical water oxi-
dation, Modar
KPEG Terraclean-CL
LAFIC
Advanced electric
reactor
Physical
O. H. Materials,
methanol extraction
Soilex
Acurex solvent wash
In-situ vitrification Bat-
telle Pacific NW for
EPRI
Biological
Composting, aerobic
anaerobic
Bio-Clean, aerobic
Sybron Bi-Chem W06
Field test with PCB
liquids
Pilot tests
Lab tests
Pilot tests
Field tests under way
Pilot tests
Pilot-scale (field tests
planned)
Pilot test of soil
Lab-scale
Lab-scale
Bench-scale
Lab-scale and concept
Estimated
D/D/R
efficiency, %b
>99.9995
>98
>90
>99.9999
97
95
(3 stages)
e
99.9
62
18-47
99.99
50
Estimated
residual
PCB, ppm
<0.1 ppb
<1 ppm
38-50
<1 ppb
<2S ppm
6-9 ppm
<2 ppm
None in vitrified
block, 0.7 ppm
in adjacent soil
504-908
825-1268
25 ppb
Test and Estimated
evaluation costs,
data needs $/m3
1,2,3,4,5,6,7 250-733
1,6 208-375
2,3,4,5,6,7 223-336
None" 830-943
2,3,6,7 401-514
5,6,7 856-913
Identity of 196-569
mixed solvent,
6,7
6 255-548
4,5,6
4,5,6
3,5,6,7 797-370
3,4,5,6,7
Rating0
4.58
5.42
5.26
4.58
4.16
3.26
5.21
4.53
2.47
2.47
4.84
1.48
NOTE—Data needs key:
1. D/D/R data
2. Residual PCB data
3. Unit operations data
4. Bench-scale data
5. Pilot-scale data
6. Field test data
7. Cost data
8. RCRA waste
3Status is defined in terms of the types of studies completed.
bD/D/R = destruction/detoxification/removal.
cThe rating was obtained as shown by the example, under Characterization.
dAER is fully permitted under TSCA in EPA Region IV for destruction of PCB.
eTreatment is continued until a residual of <2 ppm PCB's is obtained.
-------
Ben H. Carpenter is with Research Triangle Institute, Research Triangle Park. NC
27709.
Donald L. Wilson is the EPA Project Officer (see below).
The complete report, entitled "PCB Sediment Decontamination—Technical/
Economic Assessment of Selected Alternative Treatments," (Order No. PB
87-133 112/AS; Cost: $18.95, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Hazardous Waste Engineering Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
10
-------
IT P. Environmental Protection
, ',.-0n 5, Library (5PL-16)
o.;0 S Dearborn Street, Room 1676
TT «nfiQ4
Chicago, 1-1^
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