September 1987
PCS Sediment Decontamination
          Processes—Selection for
                 Test and Evaluation

                          Project Summary
                                          by
                                Ben H. Carpenter
                          Research Triangle Institute
                    Research Triangle Park, NC 27709
                           Contract No. 68-02-3992
                        RTI Project No. 471U-3065-65
        Project Officers: Donald L. Wilson, T. David Ferguson
       Hazardous Waste Environmental Research Laboratory
                             Cincinnati, OH 45268
         Hazardous Waste Engineering Research Laboratory
                   Office of Research and Development
                   U.S. Environmental Protection Agency
                             Cincinnati, OH 45268

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                PROJECT SUMMARY

   PCB  SEDIMENT DECONTAMINATION PROCESSES -
       SELECTION FOR TEST AND EVALUATION
                      by
               Ben H.  Carpenter
          Research Triangle Institute
       Research Triangle Park,  NC  27709
           Contract No.:  68-02-3992
        RTI Project No.:  471U-306S-65
      Project Officers:  Donald L. Wilson
                                and
                         T. David Ferguson
Hazardous Waste Engineering Research Laboratory
             Cincinnati. OH  45268
Hazardous Waste Engineering Research Laboratory
      Office of Research and Development
     U.S. Environmental Protection Agency
             Cincinnati. OH  45268
                September 1987

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                               PROJECT SUMMARY
                  PCS SEDIMENT DECONTAMINATION PROCESSES -
                      SELECTION FOR TEST AND EVALUATION
                              Ben H. Carpenter
ABSTRACT
    Eight alternative treatments for PCB-contaminated sediments have been
assessed as candidates for immediate thorough test and evaluation.  The proc-
esses are:  Basic Extraction Sludge Treatment (B.E.S.T), UV/Ozone or Hydrogen/
Ultrasonics Technology, Bio-Clean Naturally-Adapted Microbe. Potassium Poly-
ethylene Glycolate (KPEG). Low Energy Extraction, MODAR Supercritical Water
Oxidation, Critical Fluid Systems (CFS) Propane Extraction, and Battelle In
Situ Vitrification.
    The processes were evaluated using five criteria:  the probability of
cleaning sediments to 2 ppm or less; the availability of a teat system; the
test and evaluation effort required; the time required for future availability
of a commercial treatment process; and the probable cost of treatment using
t    process.  These criteria were addressed by engineering analysis of avail-
   e data and site visits to developers' facilities.
    The processes were ranked comparatively as to the overall desirability of
thorough test and evaluation using all five criteria collectively.  Two rating
methods were applied:  a multiplicative model using a Desirability Function
and a linear model, d-SSYS, using weighted utility functions.  Both methods
converted the process characteristics to ratings on a scale from 0 to 1 (worst
to best).  The Desirability approach normalized the characteristic using the
difference between acceptable and borderline values; d-SSYS normalized the
characteristic using the difference between the maximum and minimum values.
In calculating the overall score, the factors were weighted equally in the
Desirability Function.  Probable cost of treatment and test and evaluation
effort were assigned weights 4 to 5 times those of the other three character-
istics in the d-SSYS ranking.  These Independent approaches gave  final overall
desirability scores as follows:

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                                                 Desirability         d-SSYS
               Process                               score            score
Kale Extraction Sludge Treatment,                   0.623           0.8127
  Resources Conservation Conpany
UV/Ozone or Hydrogen/Ultrasonics Treatment.          0.621           0.8010
  Ozonic Technology, Inc.
Naturally-Adapted Microbes Process,                  0.617           0.7583
  Bio-Clean. Inc.
Potassium Polyethylene Glycolate (KPEG),             0.615           0.7434
  Galson Research, Corp.
Low Energy Extraction. New York University           0.614           0.4529
Supercritical Water Oxidation. NODAR. Inc.           0.600           0.4738
Propane Extraction Process.                          0.590           0.6214
  Critical Fluid Systems
In Situ Vitrification. Battelle                      0.460           0.2299

    While all the processes except In Situ Vitrification appear to merit
further development for this application, those three with the highest compar-
ative ratings are recommended for immediate EPA-supported thorough test and
evaluation.  These are the Basic Extraction Sludge Treatment, UV/Ozone or
Hydrogen/Ultrasonics Technology, and Bio-Clean Naturally-Adapted Microbe proc-
esses .
    This recommendation does not mean that the other processes merit no fur-
Ber T and E.  The Potassium Polyethylene Glycolate (Galson), Low Energy
Extraction (New York University), MODAR Supercritical Water Oxidation, and
Critical Fluid Systems Propane Extraction processes rank very close to the top
three.  Thus these seven processes merit consideration for testing at least
through the preliminary phases to confirm their performances.
    This project summary was developed by EPA's Hazardous Waste Engineering
Research Laboratory, Cincinnati. Ohio, 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).
INTRODUCTION
    The PCB-contaminated sediment problems in New Bedford. Massachusetts (EPA
Region I) in New York State (EPA Region II) and In Waukegan. Illinois (EPA
Region V) are reported to be the worst in the nation In terms of PCB concen-
tration and the total quantity of PCBs present.  In addition, there are
numerous industrial lagoons with large quantities of PCB contaminated sedi-
ments.  PCB contamination poses threats to both drinking water and the fishing
    istry.

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    The only available proven treatment technology Is dredging and expensive
J    neration.  Land disposal of the sediments untreated has legal restric-
    B.  The Environmental Protection Agency (EPA) has initiated a three-phase
research program to identify, validate, and demonstrate effective and economi-
cal chemical/biological processes for the removal/destruction of PCBs in sedi-
ments.  The Phase 1 study screened 64 emerging process technologies and
selected eleven for evaluation:  Potassium Polyethylene Glycolate with
Dimethyl Sulfoxide (Galson Research Corporation); O.H.N. Methanol Extraction;
Advanced Electric Reactor (J.M Huber Corporation); Acurex Solvent Wash
(Electric Power Research Institute); Bio-Clean Naturally-Adapted Microbe (Bio-
Clean. Inc.); Battelle In Situ Vitrification; Light Activated Reduction of
Chemicals ((LARC). Atlantic Research Corporation); MODAR Supercritical Water
Oxidation: Sollex Solvent Extraction; Sybron Bl-Chem 1006B; and Composting (as
studied by the Atlantic Research Corporation) (Carpenter. 1987).  The evalu-
ation showed the first eight of these to have potential for reduction of PCB
concentrations to the desired background levels or less, with minimal environ-
mental impacts and low to moderate coat.  All of the eight except the Advanced
Electric Reactor required further development and testing.
         Phase 2 study was undertaken to establish suitable factors for fur-
     assessment of candidate processes, to identify additional data needs, and
provide a basis for selection of three processes for a defensible, thorough
technical assessment, including laboratory experiemnts and field evaluation.
The study involved consultations with treatment process developers, technical
assessment of the processes, and the selection of the three highest ranking
processes for immediate teat and evaluation.
SCREENING OF CANDIDATE PROCESSES
    The seven candidate processes that required further development and test-
Ing were screened at the start of this Phase 2 (Validation) study for avail-
ability of a continuing developer and a treatment system for use in test and
evaluation of the process.  The results of this screening are given in Table
1.  Three processes were eliminated from further consideration.  The Solvent
Wash process is not available for assessment because its sponsor, the Electric
Power Research Institute, is seeking a firm to undertake the further needed
development of the process before it is ready for further consideration.  The

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 Process
                             TABLE 1.   INITIAL SCREE    '•  OF  TREATMENT  PROCESSES
         Contact
Continuing
Developer
Test Systeem)
  Available
 KPEG
 OHM Extraction
 EPRI  Solvent  Hash8
Battelle Vitrification
Bio-Clean.  Inc.
NOOAR Supercritical Mater
 Dr.  Robert  L.  Peterson                     Yes
 Galson  Research  Corporation
 6601 Klrkvllle Road
 Bast Syracuse, NY  13057

 Sue  Maaon                                   No
 OH Materials
 16406 U.S.  Rt. 224 E.
 Plndlay, OH 45839-0551
 (419) 423-3526

 Ms.  Mary McLearn                           No
 Electric Power Research Institute
 3412 HlllvleN  Avenue
 Palo Alto,  CA  94304

 Craig TlMeraan
 Battelle Pacific Northwest Laboratory      Yes
 P. 0. Box 999
 Rlchland, HA   99352

 Dr.  Lance B. Croable,                      Yes
 Director of Labs
 201  H. Burnsvllle Prkwy., Suite 130G
 Burnsvllle. MN   65337
 (612) 890-1118

Ralph A. Morgan                            Yes
Modar, Inc.
3200 Wllcrest,  Suite 220
Houston, TX  77042
 (713) 785-5615
                        Yes
                         No
                         No
                                                                                                 Yes
                       Yes
                       Yes
                                                                                         (Continued)

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 Process
                                            TABLE 1
                     Continued)
          Contact
Continuing
Developer
Test Syste*(s)
  Available
 LARC
 Basic  Extraction Sludge
 Treatment
CP  Systeas  Propane
Extraction
Ultrasonics/UV Technology
Low Energy Extraction
Process
 George Anspach
 Atlantic  Research  Corporation
 5390  Cherokee Avenue
 Alexandria, VA  22312

 Mark  lose
 Resources Conservation Co.
 3101  N.E. Northup  Hay
 Bellevlew, HA  08004
 (208) 828-2376

 Thomas J. Cody, Jr.
 CP Systems Corporation
 25 Acorn  Park
 Cambridge MA  02140
 (817) 402-1631

 Edward A. Pedzy
 Ozonic Technology, Inc.
 90 Herbert Avenue
 P. 0. Box 320
 Closter, NJ  07624
 (201) 767-1225

Halter Brenner/Barry Rugg
New York University
Dept. of Applied Science
26-36 Stuyvesant Street
New York.  NY  10003
 (212) 508-2471
     No
      No
    Yes
     Yes
    Yes
     Yes
    Yes
     Yes
    Yes
  Planned
aThis process was identified as the Acurex process in the Phase 1 study.

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developer of the OHM Extraction process has chosen not to invest In this proc-
  Is.   The developer of the LARC process has not identified sufficient Markets
  d the process is not available from the*.
    Meanwhile,  four technologies not assessed in the Phase 1 study have become
available:  the Basic Extraction Sludge Treatment (B.E.S.T.) process
(Resources Conservation Company); the Critical Fluids Systems Propane Extrac-
tion process; the (JV/Ozone or Hydrogen/Ultrasonics process (Ozonic Technology.
Inc.); and the  Low Energy Extraction process (New York University).  These
have all been assessed as candidates for thorough test and evaluation.  The
UV/Ozone or Hydrogen/Ultrasonics Technology provides continuity for the
radiant-energy  approach previously represented by the LARC process.  The other
three processes provide improved approaches to the extraction technology.  The
results of Initial screening of these processes are also given in Table 1.
DESCRIPTIONS OP TREATMENT PROCESSES
    The Basic Extraction Sludge Treatment process pretreats the feed (sedi-
ment, sludge, oily contaminants, water) with an alkaline composition, then
admixes with triethylamine (TEA) while cooling below the critical solution
temperature (U.S. Patents 3899410. 3925201. 4002562. 40S6466).  A single
Huld phase is formed from which the solid matter is separated.  The liquid
is then heated  to above the critical solution temperature to form an amlne-
rich phase and  a water-rich phase, after which the water phase is decanted.
The amine phase contains all of the oil contaminants.  It is processed to
recover the oil and contaminants, and the TEA is recycled for the processing
of additional material.
    The UV/Ozone or Hydrogen/Ultrasonics Technology Involves three factors,
all of which have been shown to be effective.  The UV/Ozone technology has
been demonstrated for destroying PCBs in industrial waste waters (Arisman et
al.. 1981).  PCBs have been extracted from soils using Tween 80 surfactant
(Scholz and Mllanowski. 1984).  They have been removed from metallic surfaces
using surfactants and ultrasonics (Smith and Sltabkhan. 1986).  UV/Hydrogen
has been shown  to destroy PCBs in non-aqueous solvents (Kitchens et al., 1979,
1984).  Ozonics Technology. Inc. Is equipped to apply all three factors in a
comparative evaluation of ozone vs hydrogen.
    The Bio-Clean process utilizes selected naturally adapted microbes to
destroy PCBs under aerobic conditions.  Contaminated sediment is charged as a

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water slurry to a digester.  The charge  is adjusted to optlaua pH and heated
^a extract the PCBs.  Surfactants May be added to promote extraction.  After
Brcraction, the slurry is cooled, neutralized, and inoculated.  The PCBs are
degraded in from 48 to 72 hours depending on the process conditions and the
•icrobes employed (Bio-Clean.  Inc..  1985) (Crombie, 1986, 1987) (Unteraan,
1985).
    The Potassium Polyethylene Glycolate process degrades PCBs by nucleophlllc
substitution.  An equal volume of contaainated sediment and reagent are blend-
ed in a reactor, and heated to remove excess water and promote the reaction.
The Galson version of the process promotes extraction of PCBs with dimethyl
sulfoxide (Peterson, 1986).  The treated sediment is settled, the reagent
removed by decantation, and the solids are washed with water  (Research Demon-
stration Permit Application, 1987).
    The Low Energy Extraction  process Involves separation of water from the
sediments, a solvent leaching  with a hydrophylic solvent  (e.g. acetone)
usually carried out in countercurrent stages, and transfer of the leached
organic contaminants to a hydrophobia solvent (e.g. kerosene) in which it Is
concentrated for final destructive treatment.  The final  treatment is a
    «rate process.  Residual contaminants in the water stream are adsorbed onto
    ntaminated sediments.  The system recycles all solvents and returns only
decontaminated sediments and water to the environment  (Brenner et al., 1986).
    The MODAR Supercritical Water Oxidation process feeds a water slurry of
contaminated sediments together with liquid oxygen to a pipe  reactor where, at
400-600 *C and 22-25 MPa,  the  contaminants dissolve and react rapidly with the
oxygen.  The reactor effluent  is cooled  by heat exchange  with fresh feed.
Pressure let down and separation of  sediments, liquid, and gases is carried
out in multiple stages to minimize erosion of valves and  optimize equilibria
 (Staszak et al.. 1987).
    The Critical Fluid System  Propane Extraction process  uses propane at ambi-
ent temperature and 1.8 MPa  (200  lb/in2) to extract PCBs  along with other oily
organlcs from a water slurry of the  sediment.  The batch  extraction  is repeat-
ed as required to achieve  specified  reductions in contaminants.  The treated
slurry is discharged after separation  from  the liquid  propane which  contains
the dissolved contaminants.  The propane solution is fed  to a separator where
the solvent is removed by  vaporization  and  recycled.   The contaminants are
      off for final treatment  in a separate process.

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    The Battelle In Situ Vitrification process was developed to stabilize
  fdionucllde-contamlnated soils by melting into a durable glass and crystal-
  ne fora (Buelt et al.. 1987).  Submerged sediments are dredged and relocated
for treatment.  Four electrodes are Inserted into the sediments in a square
array.   A path for electric current is made by placing a mixture of graphite
and glass frit between the electrodes.  Dissipation of power through the
starter materials creates temperatures high enough to melt a layer of sedi-
ments,  which establishes a conductive path.  The molten zone grows downward
through the contaminated soil.  At the high temperatures created (> 1700 *C)
organic materials pyrolyze, diffuse to the surface, and combust.  Off-gases
are collected, monitored, and treated (Tlmmerman, 1986).
DEVELOPMENT OF EVALUATION CRITERIA
    The following criteria -were used to select treatment processes for
thorough test and evaluation:
    1.   The likelihood that the process will acceptably clean up the PCB-
        contaminated sediments;
    2.   The probable cost of the application of the treatment after perform-
        ance is proven:
    3.   The relative level of T and E effort to be supported by the
        Environmental Protection Agency;
    4.   The availability of a processing system to test; and
    5.   The likely future commercial availability of the process.
    The standard selected for acceptable cleanup is a PCB concentration in
treated sediments (or soils) of 2 ppm or less.
    EPA has considered PCB requirements preparatory to their promulgation as
an amendment to the PCB regulations (40 CFR, Part 781, April 2, 1987, pp.
10688-10710).  The proposed standards require cleanup as follows.
    1.   Nonrestricted area — <, 10 ppm plus 10" cap of soil £ 1 ppm.
    2.   Restricted area — 25 ppm.
    3.   Outdoor electrical substation — 25 ppm, or 50 if a warning sign is
        maintained.
    These standards would apply to PCB spills occurring after promulgation.
       occurring earlier, and spills which are apt to result in spread of

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PCS's into other media (groundwater, surface waters, grazing landa.  and
   Ketable gardens) are to be decontaminated to requirements established at the
   cretlon of the EPA regional officer.
    These levels (10 ppm. 25 ppm, and SO ppm) are to be attained by removing
all contaminated soil exceeding these levels.  The removed soil Is subject to
disposal regulations:  cleanup to <2 ppm.  For this reason, permits issued for
alternative destruction processes generally will require that all treated
materials and by-product waste streams must have PCB concentrations of less
than 2 ug/g resolvable chromatographic peak (2 ppm).  If this condition is not
met, the effluents containing 2 ppm or greater must be disposed as if they
contained the PCB concentration of the original Influent material.  If the PCB
feed material being treated by the process is over 50 ppm PCB, then the
resulting effluents must be incinerated unless an analysis is conducted and
indicates that the PCB concentration is below 2 ppm per PCB peak.
    In accordance with these policy and treatments requirements, the cleanup
target for alternative treatments has been set at <2 ppm PCB.
    The probable cost of treatment Is presented as the cost per cubic meter of
sediment treated, based on a system sufficiently large to process 380,000 m3
«   Hudson River sediments in 2.5 years.  By focusing on a specific site and
   e of cleanup task, each process could be assessed using available data from
sampling and analyses to characterize the feed materials to the processes, and
comparative cost estimates for a specific application could be obtained.  The
sediments from the Hudson River present a variety of sediment types for test-
ing PCB-treatment processes.
    The probable cost of treatment was obtained from the developers for those
processes sufficiently supported by commercial firms, or was estimated using
as major cost elements capital costs, and operation and maintenance costs.
Treatment process requirements determined capital, energy, and maintenance
costs.  Labor rates, overhead, contingency, profit, and health and safety were
costed using standard unit values for all the processes.
    Since no full-scale systems exist for the processes under assessment.
capital costs were estimated by designing a full-scale system, utilizing the
data available as a basis.  Equipment costs were then obtained as budget esti-
mates from manufacturers or developers, or estimated using the method of
exponents:

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                              Cf - Cj (Qi/Q!)n

where:    Cj - coat for ith capacity (size);
         Qj - itn capacity;
          n - empirical constant;
         Cj - cost of reference capacity; and
         Ql - reference capacity.

    Values for the reference capital cost and the exponent, n, were obtained
in part from the literature and In part from equipment manufacturers.
    Labor hours were estimated based on an automated industrial chemical proc-
essing plant (Peters and Tlmmerhaus, 1980):

                              e2 - «i (Q2/Ql)n
where:    ej - Operator hours per day and processing step of reference case:
         62 • Operator hours per day and processing step of case 2;
         Qj - Process capacity of reference case;
         Q2 - Process capacity of case 2; and
          n • Empirical constant.
The values used in this evaluation are:       ej - 18 h/d x step;
                                              Q! - 9.07 mt/d
                                               n - 0.22

    The number of foremen and chemists are taken to be 15 percent of the num-
ber of operators.  In addition to these workers, there is one site manager.

    The hourly wages are assumed to be:       Operators:  15 $/hr
                                              Foreman:    18 $/hr
                                              Chemist:    25 $/hr
                                              Manager:    60 $/hr

    Maintenance was estimated at 10 to 15  percent of  the capital cost, depend-
ing on the number of unit operations Involved and engineering practices for
the operation.  The allowance for safety equipment was generally $0.30/»3 of
sediment treated  ($114.000  for  the cleanup of 380,000 m3 of sediment).
                                      10

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    The treatment system cost estimate was capitalized (recovered)  over the
K    years of operation taken as the base period.  Some developers provided
   atment costs that were correspondingly lower for subsequent applications.
    The test and evaluation effort required was estimated based on a compari-
son of available process data with the requirements for thorough test and
evaluation.   The following information must be provided to qualify a process
for a permit to test:
    1.  Waste characteristics;
    2.  Process engineering description;
    3.  Sampling and monitoring plan;
    4.  Accident and spill prevention and countermeasure; and
    5.  Demonstration test plan.
For these assessments, Hudson River sediments were selected as the character-
ized wastes.
    Hudson River sediment samples have been classified according to their con-
tent of clay. silt. muck, muck and wood chips, sand, sand and wood chips,
    «se sand, and coarse sand and wood chips (Tofflemire and Qulnn, 1979).
    ments have been shown to range from clay to cobbles, with the largest mass
fraction being in the sand sizes.
    The highest PCB concentration was in the muck with wood chips class, which
typically had over 30 percent silt and clay, high volatile solids and some
small but visible wood chips.  The size lowest in PCB was medium sized sand or
gravel without wood chips.
    The coarse fraction (>0.42 mm) of the sediments typically contained wood
chips, sawdust, shale chips, cinders, and coal fragments.  The fine size frac-
tions contained some fragments of the above, plus sand (containing quartz and
feldspar), silt, clay, and organic material.
    Process engineering descriptions were developed for each process assessed.
These varied in completeness because the processes varied in stage of develop-
ment from conceptual to field tested.  While unit operations were identified
and described for all processes, the descriptions were based only on per-
formance requirements.  Detailed equipment specifications have not been made.
except where necessary to obtain cost estimates (e.g., high pressure compres-
_fk| and slurry pumps).
                                     11

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    The descriptions included process  flow diagrams and identified all product
K    waste streams.  Additional  process information included summaries of bench
   ts, pilot tests, and field tests, if available.
    Sampling and monitoring  plans were then  developed, baaed on the scale of
process tests required, the  purposes of the  tests, and the extent of data
needed to characterize the process  performance  and scaleup the system to full-
scale.  Some of the processes,  when the developers' prior experience justifies
it, can be scaled-up from bench-scale  teats.  Thus, the size of system indi-
cated for test and evaluation (T and E) is the  size the developer feels can be
scaled-up with confidence.   For the needed testa, the extent of sampling and
analyses was indicated.  Methods of analysis were specified.  Prom the infor-
mation developed. T and E coats were estimated.
    For most of the processes assessed, test systems are available from the
developer.  Most developers  would need financial support of the testing time
and effort.  The availability of a  suitable  test system and any conditions/
restrictions on its use were considered for  each process.
    Accident and spill prevention and  counter-measures needs have been identi-
fied.  Part of the estimated treatment cost  is  allocated to these factors.
    The processes vary as to the strength and extent of their sponsorship.
^He developers are commercial  firms  in the  waate treatment business with
resources committed to further  commercialization of their process.  Some
developers have a need for financial  support to achieve commercialization.   In
all cases, the short-term  (2.5  years)  effort projected  in this evaluation, and
the uncertainties of further markets  make the construction of a full-scale
treatment system contingent  upon completion  of  the T and E  (with attendant EPA
approval of the process) followed  by  a contract for the cleanup work  itself.
Under these necessary conditions,  all  the processes assessed would be commer-
cially available.  The estimated time required  to make  them available varies
from process to process, however,  and this has  been taken  into consideration
in this evaluation.
PROCESS EVALUATION
    All the processes assessed  have merit.   In  selecting among them,  a ranking
system has been employed for comparative simultaneous  evaluation of all  five
criteria characteristics (Harrington,  1965). For  each  process, the
                                      12

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desirability of immediate thorough test and evaluation was expressed by a
    r ability value.  Dj:
where:    djj =  the rating of process J for criteria i for 1 from l to 5,
                0.0 < d <. 1.0.
    This function is a multiplicative decision model . although it »ay be
regarded as a linear model if it is utilized in its logarithmic form.  The
methodology does not in its original form provide for weighting of the factors
involved.  Instead, it applies equal weights to all factors.  Each factor may
be weighted, however, by the application of an appropriate exponent.  This is
shown as follows:
               0            -  (d  Xld
               uj, modified     valj  a2j   3J    "•  nj
where:   xj  - the weight of factor i

    The logarithmic form is:
                                                                          (3)
                               U + X2 lo* d2J * X3 lo« d3J * ' ' ' * xn      n
                                   0 < d < 1

    The value found for each characteristic, y. was transformed to a value of
d according to the following judgements:

    Value of d
      1.0-0.99       Represents the ultimate level of the characteristic y.
                     Improvement beyond this point would have no appreciable
                     value .
     0.99-0.80       Acceptable and excellent.  Unusually good performance.
     0.80-0.63       Acceptable and good.
     0.63-0.40       Acceptable.  Some Improvement is desirable.
     0.40-0.30       Borderline acceptability.
     0.30-0.01       Unacceptable.  This one characteristic could lead to
                     rejection of the process.
                                      13

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    The scale of d so developed is a dimensionless scale to which any  charac-
  Krlatic nay be transformed so that it »ay be Interpreted In terms of  its
  sirability for the intended application.  In this evaluation,  the most cost-
effective final process was sought that could be available in the shortest
reasonable time.
    A characteristic assessed on a numerical scale was transformed to  the
scale of "d" by the basic equation:
                       dl . e-e0.77941[(-yi + yn)/(ylh - yu)

In this equation:    yj is a value of a treatment process characteristic  1;
                       is the acceptable valuable of yl; and
                       is the borderline value of y<.
                                                                          (4)
    Table 2 shows the acceptable and borderline values of yj for each charac-
teristic rated.
           TABLE 2.  ACCEPTABLE AND BORDERLINE VALUES FOR PROCESS
                               CHARACTERISTICS
Character i s 1 1 c
Probability of cleaning to £ 2 ppm
Probable cost of treatment. $/m3
T and E effort, S/1000
Test system availability, rating
Time to provide commercial system, months
Acceptable
Value*
0.9
100
300
0.9
IS
Borderline
Value b
0.3
300
900
0.3
36
ad « 0.63 for these values.
bd * 0.37 for these values.
    The probability of cleaning to £  2  ppm was set  at 0.9  If such performance
had been demonstrated with soils of any type, 0.8 if such  performance was
projected from test data, and 0.3 if  no data were available. The use of 0.9
and 0.8 distinguishes slightly between  processes reaching  the goal of < 2 ppm
on initial tests and those for which  reaching this  goal  could be projected
from initial teats.
    The probable cost of treatment was  considered acceptable if $100/n3, and
borderline if S300/m3.
    T and E effort was considered acceptable up to  $300,000.  Values above
$900,000 were considered borderline,  but could be justified if the process had
                                      14

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potential for lowering the cost of treatment, or rated extremely well on other
fepired characteristics.
    Test system availability was rated 0.9 for an available company-provided
system with experienced operating staff and resources to commercialize the
process; 0.8 if further government purchases were required to provide a
system; and 0.3 if a suitable test system were not available.
    Time to provide a commercial system sized to effect cleanup of 152,000 m3
of sediment per year was considered acceptable at 18 months, but borderline if
36 months were required.
    Using the values of the characteristics shown in Table 2, Equation 4 was
applied to calculate the individual ratings shown for each process in Table 3.
This table also shows the overall desirability rating of the process, calcu-
lated using Equation 1.
    All the processes show acceptable "D" values.  The Basic Extraction Sludge
Treatment, UV/Ozone or Hydrogen/Ultrasonics, and Bio-Clean Naturally-Adapted
Microbe processes show the highest values, and are recommended for immediate
test and evaluation.
    This recommendation does not mean that the other processes merit no fur-
^fe* T and E.  The Potassium Polyethylene Glycolate (Galson). Low Energy
Extraction (New York University). NOOAR Supercritical Water Oxidation, and
Critical Fluid Systems Propane Extraction processes rank very close to the top
three.  Thus these seven processes merit consideration for testing at least
through the preliminary phases to confirm their performances.  The Potassium
Polyethylene Glycolate process rates lower primarily because of the high esti-
mated cost of treatment.
    The Low Energy Extraction process has a low rating because of the rela-
tively higher cost of development that may be necessary and the length of time
to commercialization.  Uncertainty about the possible commercial sponsorship
led to the lower rating for availability of a test unit.  The $827,000 Test &
Evaluation cost includes the cost of a pilot unit, however.  For the other
processes, this cost was not Included because it was contributed by the
developer or had already been purchased by the government.  The estimated cost
of treatment using this process is lower, however, than any other process.  If
this estimated cost could be attained, the development cost for the process
adds only $2.17/n3 of sediment treated:
                                      15

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               T*ft£ 3.  MMU. OSIMBIUTY OF MQIATE T AND E OF THE HOT OMIMTC PBggg

Probability of clean-
Ing tD<2ppe
d ratlfig
FT09HDM GDft OT
. »i_3
Grenenc, J/B*
d rating
T and E ei'ori
$1000
d rating
Availability of a
fyetee for a tart
jtura purdne by
govern, raoulrad
futerapunJuee by
govern, not required
d rating
Lflerty futura avall-
etnlTty or tre prooeei
OMammmm
BUIUB
d rating
OMrall detlrablllty, 0
erllett futura evedl.
latBt future avail.

KFGB.
feleon

0.9
0.63

160-191
0.54*

216
0.66





0.9
0.63


19.5
0.62

0.615
0.615
0.615

fcdar
Supercritical
Hater

O.I
0.59

86-136
0.62

483
0.56





0.9
0.63


21.5
0.59

0.60
0.60
0.60

Bio-Clem

0.8
0.63

156
0.57

166
0.68





0.9
0.63


19
0.62

0.617
0.617
0.617
W/tam-
HydrogW
Ultraetnla
Tadnology

0.8
0.59

90-120
0.63

151
0.69





0.9
0.63


21-24
0.59-0.55

0.625
0.616
0.621
CfS
Extraction

0.8
0.59

153-264
0.50

123
0.69





0.9
0.63


25
0.54

0.59
0.59
0.59
u»*»w
8.E.S.T. Extraction

0.8 0.9
0.59 0.63

133 50-57
0.59 0.68

149 ITO-eZT*
0.69 0.64




0.8
0.9
0.63 0.59


19 25
0.62 0.54

0.623 0.614
0.623 0.614
0.623 0.614

InSItu
Vltrlflcsti

0.9
0.63

443483
0.16

400
0.59




0.8
0.59


19-24
0.62-0.55

0.46
0.45
0.46

of $170,000' 1f
by epmearlng fin.  A
                                     «t of $280,000 *» «a 1n the ^k«1m to allot fcr tfe uorealnty.
                                          16

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                        $827.000 + 380.000 »3 - $2.17.
•Mis would have  a  small impact on the final treatment  cost.  If added to the
 estimated $76-$83/m3.   From this point of view,  the major obstacle to a higher
 rating for this  project is the 25-month development time required, and the
 lack of a firmly committed commercial sponsor for the  test system.
    The NOOAR process  has a high T and E cost, but a potential application to
 a broad range of contaminants besides PCBs.
    The In Situ  Vitrification process has the highest  estimated  cost of treat-
 ment,  which  derives in significant proportion from the cost of electricity and
 consumable electrodes  used in the treatment.  As previously mentioned, the
 advantages of in situ  treatment could not be bad in the treatment of submerged
 sediments.   The  fact that a solid mass is the product  presents a problem  in
 disposal.  The process appears best suited for in-situ fixation  of radioactive
 wastes.
 APPLICATION  OF ALTERNATIVE PROCESS SELECTION METHODOLOGY
    While this project was under way, an alternative process selection method-
 ology  became available at HWERL.  The methodology is available as a computer
•Bgram entitled "d-SSVS. A Computer Model for the Evaluation of Competing
 Uncertainties,"  (Klee. 1987).  This method was applied In addition to the
 Desirability Function  approach.
    The D-SSYS calculates weights for each evaluation factor using values of
 weight ratios assigned by the user.  Weight ratios were assigned to emphasize
 the Importance of  the  ranges of treatment cost and test-and-evaluatlon cost.
 The range of ratings for probability of cleaning to <2 ppm PCBs  is only 0.1
 (Table 3),  Indicating  that all the processes might reasonably be expected to
 meet  the requirement.   The availability of a test system was not considered  as
 Important as the total test and evaluation cost.  The time required  to make  a
 commercial  process available showed a range of only six months,  and was  judged
 of lesser importance than the two major costs assessed.  All ratios among the
 five  factors that  resulted from these assignments are shown below as  a matrix.
 For example, the ratio (test system avallablllty)/(T and E cost) is  shown as
 the intersection of Row 4 and Column 3 as 0.2.
                                      17

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Clean to 2 ppm
Cost
T and E Cost
Test system availability
Early com. availability
Clean
to
2 ppm
1
5
S
1
1.25


Cost
0.2
1
1
0.2
0.25

T & E
Cost
0.2
1
1
0.2
0.25

Test System
Availability
1
5
5
1
1.25
                              Early
                             Commercial
                            Availability

                                0.8
                                4
                                4
                                0.8
                                1
    Prom these ratios and the following tabular algorithm, the factor weights
(W) were generated.
             Factors

    Clean to 2 ppm
    T and E Cost
    Future commercial proc.
    Test system availability
    Cost
Ratios
0.2000
4.
1.
0.
000
25
2000
0.20
1.00
0.25
0.20
5.000
Weights.

   0.0755
   0.3774
   0.0943
   0.0755
   0.3774
                                                    2.65
The procedure for weight generation  is as  follows:
       Construct an Intermediate weighting scale  (the w-column) by the follow-
       ing procedure.  Opposite that  last factor  enter a  "1".  The remaining
       numbers in this column are  formed by  the product of  its predecessor and
       Ratio value opposite  it in  a sort of  zigzag route  up the column.  For
       example, the first w-value, 0.20 is the product of the second w-value
       (1.00) and the first  Ratio-value (0.2000).

     •  Total the w-values.   This total is 2.65.   Construct  a column of stan-
       dardized weights by dividing each element  of the w-column by this total
       to obtain the W-column.  The elements in the W-column will, perforce.
       total one.

     The program then scales  the factor scores to  obtain a linear utility func-
tion:
                         y1  «  b0  +  bj  (factor score)

                                  0  < y1  < 1.
                                     (5)
     In applying the scaling procedure to the two factors  "Probability of
Cleaning to £ 2 ppm" and  "Availability of a Test System," It is  noted that
these are positive factors  (the higher the factor score,  the better  the proc-
"s_L and the  'y1 values are obtained by:
                                      18

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                         	score}j - •inimua score}4
                          maximum score£j - minimum scorejj
                                            (6)
The other three factors are noted to be negative (the higher the factor score,
the worse the process) and the y1 values are obtained by:
                              maximum scorej.| - acorejj
                          maximum scorejj - minimum score
                           ij
                                            (7)
    The yjj values for the five factors by which each of the eight processes
were assessed are given In Table 4.
            TABLE 4.  SCALED RATINGS OF EIGHT TREATMENT PROCESSES
Clean

2
KPEG (Gal son)
MODAR
Bio-Clean
UV/OZ or H2/Ultrasonlcs
§ Propane Extraction
.S.T.
Energy Extraction
In Situ Vitrification
to
pp»
1
0
0
0
0
0
1
1
Probable
Tr. Cost
0.60
0.87
0.67
0.89
0.45
0.77
1
0
T & E
Cost
0.75
0.043
0.89
0.93
1
0.93
0
0.26
Test System
Availability
1
1
1
1
1
1
0
0
Early
Commercial
Availability
0.92
0.58
1
0.42
0
1
0
0.58
    Depending on the users degree  of  risk that  he  is  willing  to accept. d-SSYS
fits a utility function to the y1  values  via the following  function:
                               utility «  y'f .                             (8)

The exponent f is evaluated  by presenting the user with a structured  lottery.
    d-SSYS requires s comparison between  two simple lotteries for each factor
rated.
             Lottery  1
SOX chance of most undesirable rating.
SOX chance of most desirable rating.
                                      19

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             Lottery 2  «  |   X value of the ratine for certain.
                           I
    Using probable treatment cost as an example, RTI selected for Lottery 1:
                  SOX chance of a treatment cost of $313/m3
                  SOX change of a treatment cost of $80/m3
and an X value equal to the mathematical expectation of Lottery 1 for
Lottery 2:
                   (0.5 X $313) + (O.S X 80) « $196.50/m3.
    The value of $196.50/m3 on the y' scale is
                                $313 - $196.6
                          y« - 	 « 0.5
                                  $313 - $80

    The utility of Lottery 2 is easily determined, since it is equal to the
utility of Lottery 1:
           (0.5)(utility of $313/m3) + (0.5)(utility of $80/m3) -
                       (O.S x 0.0) + (0.5 x 1) - 0.5.
^^m Equation 8:
                           f - (In utility)/ln y'                         (9)
                           f - (In 0.5)/ln 0.5 • 1
    Note that if Lottery 2 had been set at a lower cost for certain, f would
have been greater than 1 and the  function would have been a risk-taking one,
in that one would be willing to pay more for Lottery 1 in the hope of gaining
a treatment cost of $80/m3.
    The remaining utilities for each factor are then calculated using Equation
8 (Klee, 1987, p. 23).
    Using the ratings scaled by Equation 8, the program computes an overall
deterministic score for each treatment process as the  sum of the scaled factor
ratings times the scaled factor weights.  Using the factor ratings of Table 44
(which equal the utility when  f - 1) and the weights cited above, the follow-
ing deterministic scores were  obtained for the  treatment processes (Table 5).
                                      20

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            TABLE 5.  DETERMINISTIC SCORES FOR TREATMENT PROCESSES
       	Proce88	Score
        Basic Extraction Sludge Treatment                        0  8127
        UV/Ozone or Hydrogen/Ultrasonics                         0  8010
        Bio-Clean Naturally-Adapted Microbe                      0  7583
        Potassium Polyethylene Glycolate. Galaon                 0  7434
        Critical Fluid Systems (CFS) Propane Extraction          0  6214
        MOOAR Supercritical Water Oxidation                      0*4738
        Low Energy Extraction. New York University               0
        In Situ Vitrification. Batteile                           '
     The  highest  scores were attained by the Basic Extraction  Sludge Treatment,
 UV/Ozone or Hydrogen/Ultrasonics Technology,  and Bio-Clean Naturally-Adapted
 Microbe  processes,  the same processes that ranked highest using the Desir-
 ability  Function ranking methodology.   These  are recommended  for  Immediate
 test and evaluation.
     In the application of this  ranking,  probable treatment cost and test and
 evaluation cost  were assigned weights 4  to 6  times those of the other three
gctors.  This Increased emphasis  on the costs  involved did not change the top
Pree processes.  With different weights assigned,  it would be possible to
 obtain a different ranking  of the  processes.
 CONCLUSIONS

     Eight emerging treatment processes for  decontamination of PCB-contaminated
 sediments have been evaluated as candidates for  thorough test and evaluation
 (T and E) using a test system judged of  sufficient  size by the developer to
 provide performance, cost,  and sealeup data for  a  large commercial plant.   The
processes assessed include:  Basic Extraction Sludge Treatment (B.E.S.T);  Bio-
Clean Naturally-Adapted Microbe; Critical Fluid  Systems Propane Extraction;
Potassium Polyethylene Glycolate. Galson; Low Energy Extraction.  New York
University;  MODAR Supercritical Water Oxidation; UV/Oxone or Hydrogen/Ultra-
sonics Technology;  and Batteile  In Situ Vitrification.
    The processes were evaluated using as criteria:
    •  The probability of cleaning sediments to <2 ppm PCBs;
    •  The probable cost  of treatment:
                                     21

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    •   The relative level of Test and Evaluation effort to be supported by
       EPA;

    •   The availability of a processing system to test; and

    •   The likely future commercial availability of the process.

    While all the processes except perhaps In Situ Vitrification merit further

development for treatment of sediments, comparative simultaneous evaluation of

their  ratings on a scale of 0 to 1 gave the following results:
                                                   Relative Desirability of
                                                 Thorough Test and Evaluation
                                                 Desirability        d-SSYS
               Process                               score            score

Basic Extraction Sludge Treatment,                   0.623           0.8127
  Resources Conservation Company
UV/Ozone or Hydrogen/Ultrasonics Treatment.          0.621           0.8010
  Ozonic Technology, Inc.
Naturally-Adapted Microbes Process,                  0.617           0.7583
  Bio-Clean. Inc.
          Polyethylene Glycolate (KPEG),             0.615           0.7434
         Research, Corp.
           Extraction. New York University           0.614           0.4529
Supercritical Water Oxidation, MODAR, Inc.           0.600           0.4738
Propane Extraction Process,                          0.590           0.6214
  Critical Fluid Systems
In Situ Vitrification, Battelle                      0.460           0.2299
    The Basic Extraction Sludge Treatment Process (Resources Conservation

Co.), UV/Ozone or Hydrogen/Ultrasonics Technology, and Bio-Clean Naturally-

Adapted Microbe processes have the highest ratings, and are recommended for

immediate thorough test and evaluation.  This evaluation was confirmed using

the d-SSYS Computer Model for the Evaluation of Competing Alternatives (Klee.

1987).

    The Potassium Polyethylene Glycolate (Galson). Low Energy Extraction (New

York University), MODAR Supercritical Water Oxidation, and Critical Fluid

Systems Propane Extraction processes ranked very close to the top three.

These processes have potential for treatment of a broad range of hazardous

contaminants and are recommended for at least those preliminary phases of

   ^ough test and evaluation which confirm performance and establish process

     Peters for pilot-scale tests.

    References cited are identified fully in the full report.


                                     22

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Ben H.  Carpenter is with the Research Triangle Institute,  Research
Triangle Park.  NC 27709.  Donald L. Wilson and T. David Ferguson are  the
EPA Project Officers (see below).  The complete report, entitled "PCB
Sediment Decontamination Processes - Selection for Test and Evaluation."
(Order No.  PB                 , Cost               ,  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:

            Hazardous Waste Engineering Research Laboratory
            U.S. Environmental Protection Agency
            Cincinnati. OH  45268
                                   23

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