EPA/540/A5-90/002August 1990

CF Systems Organics Extraction ProcessNew Bedford Harbor, Massachusetts

Applications Analysis Report

Risk Reduction Engineering LaboratoryOffice of Research and Development

U.S. Environmental Protection AgencyCincinnati, Ohio 45268

Notice

The information in this document has been funded by the U.S. EnvironmentalProtection Agency under Contract No. 68-03-3485 and the Superfund InnovativeTechnology Evaluation (SITE) Program. It has been subjected to the Agency’s peerreview and administrative review and it has been approved for publication as aUSEPA document. Mention of trade names or commercial products does notconstitute an endorsement or recommendation for use.

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Foreword

The SITE program was authorized in the 1986 Superfund amendments. Theprogram is a joint effort between EPA’s Office of Research and Development andOffice of Solid Waste and Emergency Response. The purpose of the program is toassist the development of hazardous waste treatment technologies necessary toimplement new cleanup standards that require greater reliance on permanentremedies. This is accomplished through technology demonstrations that aredesigned to provide engineering and cost data on selected technologies.

This project consists of an analysis of CF Systems’ proprietary organicsextraction process. The technology demonstration took place at the New BedfordHarbor Superfund site, where harbor sediments are contaminated with polychlori-nated biphenyls and other toxics. The demonstration effort was directed atobtaining information on the performance and cost of the process for use inassessments at other sites. Documentation will consist of two reports. A Technol-ogy Evaluation Report described the field activities and laboratory results. TheApplications Analysis provides an interpretation of the data and conclusions on theresults and potential applicability of the technology including a projection of costsfrom the demonstrated pilot unit to a full-scale commercial unit.

Additional copies of this report may be obtained at no charge from EPA’sCenter for Environmental Research Information, 26 West Martin Luther KingDrive, Cincinnati, Ohio 45268, using the EPA document number found on thereport’s front cover. Once this supply is exhausted, copies can be purchased fromthe National Technical Information Service, Ravensworth Bldg., Springfield, VA2216 1, (703) 487-4600. Reference copies will be available at EPA libraries in theirHazardous Waste Collection. You can also call the SITE Clearinghouse hotline atl-800-424-9346 or 382-3000 in Washingto

Office of EnvironmentalEngineering and TechnologyDemonstration

MLgaret M. Kelly, DirectorTechnology Staff, Officeof Program Managementand Technology OS WER

111

Abstract

The SITE Program Demonstration of the CF Systems organics extractiontechnology was conducted to obtain specific operating and cost information thatcould be used in evaluating the potential applicability of the technology toSuperfund sites. The demonstration was conducted concurrently with dredgingstudies managed by the U.S. Army Corps of Engineers at the New Bedford HarborSuper-fund site in Massachusetts. Contaminated sediments were treated by CFSystems’ Pit Cleanup Unit 0) that used a liquefied propane and butane mixtureas the extraction solvent. The PCU was a trailer-mounted system with a designcapacity of 1.5 gallons per minute (gpm), or 20 barrels per day (bbl/day). Thetechnology extracts organics from contaminated soils based on solubility oforganics in a mixture of liquefied propane and butane.

The objectives included an evaluation of (1) the unit’s performance, (2) systemoperating conditions, (3) health and safety considerations, (4) equipment andsystem materials handling problems, and (5) projected system economics. Theconclusions drawn from the test results and other available data are:

. Polychlorinated biphenyl (PCB) extraction efficiencies of 90 percentwere achieved for New Bedford Harbor sediments containing PCBsranging from 350 to 2,575 parts per million (ppm). Concentrationsof PCBs in the clean sediment were as low as 8 ppm.

. Extraction efficiencies of 95 percent are demonstrated in the laboratoryfor volatile and semivolatile organics contained in aqueous andsemisolid waste matrices.

l Some operating problems occurred during the SITE tests, such asintermittant retention of solids in system hardware and foaming in thetreated sediment collection tanks. Corrective measures wereidentified, and will be incorporated in the full-scale commercialunit.

l Operation of the PCU at New Bedford did not present any threats tothe health and safety of operators or the local community.

. The projected cost of applying the technology to a full-scale cleanupat New Bedford Harbor ranges from $148 to $447 per ton. Theseprojections include pre- and post-treatment costs, material handlingcosts, and costs for a spccializcd process configuration designed toremediate sediments, however the post-treatment cost did not includethe final destruction of the concentrated extract.

l Site specific pre- and post-treatment costs account for approximatelyone-third of the estimated costs.

. The predicted onstream factor for the full-scale commercial unit isthe variable that introduces the greatest uncertainty to the costestimates.

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ContentsPage...

Foreword .........................................................................................................................................111

Abstract .......................................................................................................................................ivFigures ............................................................................................................................................viTables .............................................................................................................................................viAcknowledgments .........................................................................................................................viiAbbreviations and Symbols ..........................................................................................................ix

1. EXECUTIVE SUMMARY .......................................................................................................11.1 SUMMARY ........................................................................................................................11.2 CONCLUSIONS ...............................................................................................................11.3 APPLICATIONS ANALYSIS ...........................................................................................21.4 RESULTS ...........................................................................................................................3

2. INTRODUCTION .......................................................................................................................72.1 THE SITE PROGRAM ......................................................................................................72.2 SITE PROGRAM REPORTS ............................................................................................72.3 KEY CONTACTS. 8........................ .......................................................................................

3. TECHNOLOGY APPLICATIONS ANALYSIS ......................................................................93.1 OVERALL TECHNOLOGY APPROACH .......................................................................93.2 TECHNOLOGY EVALUATION .....................................................................................103.3 WASTE CHARACTERISTICS AND OPERATING REQUIREMENTS ...................... 143.4 MATERIAL HANDLING REQUIREMENTS ................................................................... 173.5 HEALTH AND SAFETY ISSUES. ..................................................................................183.6 TESTING PROCEDURES ................................................................................................18

4. ECONOMIC ANALYSIS ........................................................................................................214.1 INTRODUCTION.............................................................................................................214.2 BASIS FOR PROCESS DESIGN, SIZING, AND COSTING ....................................... 214.3 DEVELOPER’S ESTIMATE FOR A NEW BEDFORD HARBOR CLEANUP.. ........... 244.4 EVALUATION OF THE DEVELOPER’S ESTIMATE ................................................. 274.5 EXTRAPOLATION OF CF SYSTEMS’ SLUDGE TREATMENT COSTS

TO OTHER SITES............................................................................................................294.6 CONCLUSIONS AND RECOMMENDATIONS ............................................................29

APPENDICES

A. PROCESS DESCRIPTION .......................................................................................................31B . DEVELOPER (VENDOR) COMMENTS ................................................................................45C. SITE DEMONSTRATION RESULTS .....................................................................................55

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Contents (Continued)

FiguresNumber Page

3-l New Bedford Harbor Application Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

TablesNumber Page

l-l CF Systems’ Soils Treatment Extraction Unit Designs .......................................................33-l Bench-Scale Test Results for Wastewaters and Groundwaters ........................................113-2 Bench-Scale Test Results for Sludges and Soils .............................................................123-3 Texaco, Port Arthur Performance Data .............................................................................153-4 United Creosote Superfund Site Performance Data ..........................................................163-5 Sludge and Soil Feed Requirements ................................................................................164-l Base Case and Hot Spot Case Summary .......................................................................264-2 Estimated Cost ................................................................................................................28

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Acknowledgments

This report was prepared under the direction and coordination of RichardValentinetti, EPA SITE Program Manager in the Office of Environmental Engi-neering & Technology Development in Washington, D.C. Contributors and re-viewers for this report were Frank Ciavattieri of EPA Region I, Remedial ProjectManager for the New Bedford Harbor Superfund Site; Jim Cummings from theOffice of Solid Waste and Emergency Response; Paul de Percin, Gordon Evans,Diana Guzman, and Laurel Staley from the Office of Research and Development;Christopher Shallice and Thomas Cody, Jr. from CF Systems Corporation; andAlan Fowler of EBASCO Services, Inc.

This report was prepared for EPA’s SITE Program by Science ApplicationsInternational Corporation (SAIC), McLean, VA, for the U.S. EnvironmentalProtection Agency under Contract No. 68-03-3485, by Don Davidson, JohnBonacci, Richard Hergenroeder, and Omer Kitaplioglu. Laboratory analyses wereconducted by E.C. Jordan, Inc., Portland, ME, and Radian Corp. Austin, TX.

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Abbreviations and Symbols

amps

ASTM

bbl/day

BDAT

BNAs

Cd

COE

cP

Cr

CR

C u

CWA

dPa.s

ECD

EPA

EPT

EP Tox

F

FK

gGC

gpd

gpmkw-hr

lbs

lb/gallb/min

max

MBAS

mg

mg/kgmin

ms

MSA

amperes

American Society forTesting and Materials

barrels per day

best demonstratedavailable technology

base/neutral and acidextractable compounds

cadmium

U.S. Army Corps of Engineers

centipoise

chromium

column reboiler

copper

Clean Water Act

decapascal.seconds

electron capture detector

Environmental Protection Agency

extract product tank

Extraction Procedure ToxicityTest - leach test

Fahrenheit

feed kettle

grams

gas chromatography

gallons per day

gallons per minute

kilowatt hours

pounds

pounds per gallon

pounds per minute

maximum

methylene blue active substances

milligrams

milligrams per kilogram

minimum

mass spectrometry

method of standard additions

MS/MSD

ND

NIOSH

NR

ORD

OSWER

OVA

oz

PAHs

Pb

PCBs

PCU

PNAs

ppm

psigQAQCRCRA

RPD

RREL

RSD

SARA

SBT

SITE

SRC

TDS

TS

TSD

TSS

VAC

VOAs

Zn

<

matrix spike/matrix spike duplicate

not detected

National Institute of OccupationalSafety and Health

not reported

Office of Research and Development

Office of Solid Waste andEmergency Response

organic vapor analyzer

ounces

polyaromatic hydrocarbons

lead

polychlorinated biphenyls

Pit Cleanup Unit

polynuclear aromatics

parts per million

pounds per square inch gauge

quality assurance

quality control

Resource Conservation andRecovery Act of 1976

relative percent difference

Risk Reduction EngineeringLaboratory

relative standard deviation

Superfund Amendments andReauthorization Act of 1986

still bottoms tank

Superfund InnovativeTechnology Evaluation Program

solvent recovery column

total dissolved solids

total solids

treatment, storage, and disposal

total suspended solids

volts, alternating current

volatile organic analytes

zinc

less than

Section 1Executive Summary

1.1 Summary 1.2 ConclusionsThe CF Systems Corporation pilot-scale soil treat- The conclusions drawn from reviewing limited opera-

ment technology was tested and evaluated under EPA’s tional data on the CF Systems technology, both from theSuperfund Innovative Technology Evaluation (SITE) SITE evaluation tests and from the information suppliedProgram. The technology uses a mixture of liquefied by the developer, are:propane and butane as a solvent to extract organics fromharbor sediments. Successful application of the technol-ogy depended on the ability of the organic pollutants to besolubilized by the solvent. Mixing solvent with wasteseeks to achieve intimate contact between the solvent andthe contaminants. Variables include solvent-to-feed ra-tios, mixing energy, and residence time in the reactor.Following decanting of the solvent-organics mixture fromthe solids and water, pressure reduction vaporizes thesolvent and separates it from the organics. The solvent isrecovered and compressed to a liquid for reuse. Theseparated organics are collected for disposal. Treated soilmay require dewatering. Soil that meets cleanup standardscan be returned to the site. Water that meets applicablestandards can be discharged directly to a stream or to aPublicly Owned Treatment Works.

Solvent extraction technology relies upon the prefer-ential solubility of organics in certain solvents versus thesoil and water in which the contaminants are found inenvironmental matrices. Application of solvent extractionat Supcrfund sites is essentially a pretreatment step, result-ing in significant reductions in the amount of material thatmust be subjected to further treatment, e.g., incineration.Thus, in soils contaminated with oil and grease at 1,000ppm (0.1 percent), the amount of material requiring incin-eration would be reduced by a factor of 1,000 (assuming aremoval efficiency of 99 percent).

Removal efficiency depends on a number of factorsincluding the ability of the technology to bring the solventinto proximity with the contaminant(s) and the degree towhich thecontaminantsprefer thesolvent to the medium inwhich they are located.

CF Systems also markets a wastcwatcr treatmentsystem that uses liquefied carbon dioxide as the solvent.This system was not tested under the SITE Program.

The soils treatment system was tested on sedi-ments obtained from New Bedford Harbor inMassachusetts that contained PCBs at 350 and2,575 ppm concentration levels. A pilot-scalemobile unit was used for this test. This unitrequired recycle of product to simulate theoperation of a full-scale, four-stage unit. Thismode of operation caused material handlingproblems which in turn restrictedprocess through-put. The multiple-pass mode of the demon -stration limits our ability to extrapolate to full-scale units intended to be operated in a once-through mode.The technology can separate organics from har-bor sediments, sludges, and soils. PCB extrac-tion efficiencies greater than 90 percent wereachieved for New Bedford Harbor sediments andattained levels as low as 8 ppm for PCBs. CFSystems’ pilot-scale unit has also been successfully demonstrated at petroleum refineries, pet-rochemical plants, and hazardous waste treat-ment storage and disposal facilities.The technology can also separate organics fromwastewater; however, the mixing equipmentand solvent used are different from that used forsludges and soils. Although the SITE programtests were conducted only on the soils treatingunit, some information is presented in this reporton the wastewater treatment unit.Operational control was difficult to maintainduring the New Bedford Harbor tests. Solventflow fluctuated widely andcausedthe solvent-to-feed ratio to fall below specifications. Solidswere retained in process hardware, solids wereobserved in organic extracts, and foaming oftreated sediments also occurred. The vendor

believes that these problems are correctable byequipment design changes and by operating ina once-through mode instead of a recycle mode.Bench-scale test results show the potential forextraction of a broad range of organics fromwastewater.groundwater,andsemisolids. Thesetests were useful for determining whether or notorganics contained in a waste matrix will be ex-tracted by a liquefied solvent such as carbondioxide or propane. Laboratory results indicatedthat equilibrium conditions did not limit reduc-tion of solid PCB content to levels of 10 ppm.Pretreatment technology may be necessary tocondition feed materials. Coarse solids removalmay be required to maintain feed sediment par-ticle sizes below three-sixteenths inch; watermust be added to viscous sludges or dry soils andheat must be supplied to feeds less than 60degrees Fahrenheit. Post-treatment technologyalso may be necessary such as thermal destruc-tion of the concentrated extract. In some cases,the cleaned material could be subjected to fur-ther treatment.Water addition during the SITE Demonstrationto achieve required viscosities increased themass of waste by about 33 percent. Such wateraddition may result in a requirement for post-treatment dewatering.Costs for implementing the CF Systems’ tech-nology at New Bedford Harbor were projectedbased on an economic model. Since a full-scaleunithasbeenplacedin thefieldonlyrecently,op-erating and cost data for a full-scale system werenot available. The estimated cost for removing90 percent of the PCBs from New Bedford Har-bor sediments containing 580 ppm is $148 perton, which includespre- and post-treatment costs.The cost for removing 99.9 percent of the PCBsfrom New Bedford Harbor “hot spots” contain-ing 10,000 ppm is $447 per ton including pre-and post-treatment costs. These costs representa range of costs anticipated for full-scale appli-cation of the technology at New Bedford Harbor.Approximately one-third of the estimated costsare pre- and post-treatment costs. These cost es-timates did not include the final destruction of theconcentrated extract.

l CF Systems has designed and fabricated a 50-ton-per-day (200 barrels/day) soils treatmentunit for Star Enterprises, Inc.facility (Texaco) inPort Arthur, Texas, to treat API separator sludge.Oils extracted from the sludge will be rccovercd

for reuse. CF Systems has agreed to allow theSITE program to monitor the operation of thisunit to demonstrate that operability parametersassociated with materials handling and on-streamfactors are within commercial design claims.

1.3 Applications AnalysisApplications of the CF Systems organics extraction

technology depend on waste characteristics, waste vol-ume, and degree of pollutant removal required. Wastecharacteristics determine the type of solvent to be used andthe need for pre- and post-treatment. If a waste containsorganics, such as PCBs and PAHs, that are not very solublein water then a hydrocarbon solvent, such as propane or apropane and butane mixture, is used. Less soluble organicsare typically sorbed to soil particles found in sludges,therefore propane is commonly used to extract organicsfrom soils and sludges.

Pre- and post-treatment must be considered if feedmaterials (1) contain gravel or cobbles, (2) are below 60degrees F, or (3) are not pumpable. For wastewaters andgroundwaters that are relatively free of solids, liquefiedcarbon dioxide is the preferred extraction solvent since thissolvent seeks polar materials in water, is nontoxic. and hasfavorable thermodynamic properties. CF Systems ini-tially assesses feed materials by conducting bench-scaletests in the laboratory. If bench-scale tests are successful,pilot-scale tests are run with either a laboratory-based pilotscale unit or a mobile, trailer-mounted unit. Only thepropane-based unit was evaluated during the SITE testsand is therefore the primary subject of this report.

CF Systems offers standard modular systems fordifferent markets and applications. For sludge and solidstreatment the capacity range is about 10 to 1,000 tons perday per unit and liquefied propane or a butane andpropane mixture is the extraction solvent. The capacityrange for wastewater treatment is about 5 to 150 gpm andliquefied carbon dioxide is used as the extraction solvent.Systems of these size ranges, constructed of carbon orstainless steel, can be modularized, shipped, and fieldassembled economically. As a result of this approach,several unit sizes have been developed and designed. Theunits can be configured in parallel if high throughputcapacities are required. If high extraction efficiencies arenecessary, the units can be arranged in series.

The soils treatment unit evaluated during the SITEtests at New Bedford Harbor was the PCU-20, which israted at a 5-ton-per-day nominal capacity. The unit is oftenused for pilot-scale tests, but is also used for remediatingsmall volumes of contaminated sludges or soils. The PCU-20 has a l-1/2 foot diameter, two-stage extractor that useda mixture of propane and butane as the extraction solvent.

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During the SITE tests, treated sediments were recycledthrough the unit to simulate the design and operation of afull-scale, four-stage unit that has 6-foot diameter extrac-tors.

CF Systems has proposed two types of systems forNew Bedford. The first system, the base case,applies to thetreatment of 880,000 tons (695,000 cubic yards) of harborsediments containing approximately 580ppm of PCB. Thesecond system applies to the treatment of 63,000 tons(50,000 cubic yards) of sediments from harbor “hot spots”that contain approximately 10,000 ppm. Each systemdiffers from the ECU-20 tested at New Bedford. For thebase case, two PCU-1000s, each rated at 250 tons per day,would be placed in parallel to accommodate the largevolume of waste to be treated. For the hot spot, four PCU-500s each rated at 125 tons per day would be used and thesewould be configured in pairs so that two parallel trains areavailable with each train providing a total of 8 stages oftreatment for the contaminated sediments.

Key extraction system elements of generic, prede-signed soils treatment units offered by CF Systems areshown in Table 1 - 1. These designs apply to the remcdia-tion of soils and sludges at any site but do not include anysite-specific support facilities or pre- and post-treatmentequipment. All components of the various units can beobtained from “off-the-shelf’ sources and no custom fab-rications are required.

1.4 ResultsPerformance

The most extensive evaluation of the CF Systemstechnology was performed as part of the SITE tests at NewBedford. Qualitative results are also reported by CFSystems for three field demonstrations of a pilot-scale unitand for numerous bench-scale laboratory tests. CF Sys-tems achieved an overall PCB concentration reduction ofover 90 percent for New Bedford Harbor sediment samplesthat contained 350 ppm and 2,575 ppm during the SITEtests. The unit generally operated within specified condi-tions for flowrates, pressure, temperature, pH, and viscos-ity. Deviations from operating specifications could not becorrelated to changes in extraction efficiency. No signifi-cant releases of pollutants to the atmosphere or surround-ing area soils occurred. Results of the demonstration testsshow that the CF Systems technology is capable of reduc-ing the PCB content of contaminated sediment by greaterthan 90 percent without a risk to operating personnel or thesurrounding community.

CF Systems reports the following field demonstrationresults for its pilot-scale units:

l Texaco: A unit was run September and Octoberof 1987. Different feed types were run throughthe system including material from a clay pit,ditch skimmer sludge, tank bottoms, and othermiscellaneous waste streams found at the PortArthur refinery site. The system consistently

Table l-l. CF Systems’ Soils Treatment Extraction Unit Designs

Unit Nominal Throughput Extractor Number ofDesignation (Tons Per Dav) 11) Diameter (feet) Staoes

PCU-20 12 1.5 2

PCU-200 50 4 4

PCU-500 125 6 4

PCU-1000 250 6.5 4

NOTES:

SitePreparation (2)Cost (Dollars)

N/A

$350,000

$700,000

$2,000,000

(1)

(2)

1.26 tons is equivalent to 1 cubic yard of New Bedford Harbor sediments.

Site preparation costs include clearing, grading, constructing a foundation, and providing access for utilities.Costs are applicable to any site.

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achieved high removals of total oil and grease toless than 1 percent residual of the dry solids.Levels of individual components, includingbenzene, ethylbenzene, toluene, xylene, naph-thalene, phenanthracene, pyrene, and other poly-nuclear aromatics (PNAs), met or bettered theexisting best demonstrated available technology(BDAT) standards. In many cases, these levelswere found to be below detection limits. Fol-lowing the demonstration, Star (Texaco) awardedCF Systems a contract to provide a 50-ton-per-day commercial unit to remediate 20,000 cubicyards of API separator sludges and ditch skim-mer wastes. This unit was fully operational inJuly 1989.

l Petro-Canada: A unit was operated at the Petro-Canada refinery in Montreal for a six-weekperiod. During this time, the unit successfullyprocessed 14 different feed types, ranging fromAPI separator sludges to contaminated solids.The unit consistently achieved organic removallevels better than existing BDAT standards.

l Tricil: A unit was used to run a series of demon-stration tests at Tricil Canada’s treatment, stor-age, and disposal (TSD) facility in the Provinceof Ontario. The feeds processed included APIseparator sludge, paint wastes, synthetic rubberprocess waste, and coal tar wastes. The level ofvolatile organics was reduced such that disposalof the material in a local Canadian landfill wasacceptable and volumes for disposal were sig-nificantly reduced.

l BASF: A mobile treatment system was run atthe BASF Kearny, New Jersey, plant site. Oneof the waste streams from this plant is an emul-siliedstreamcontainingdi-octyl phthalate(DOP),water, and other organic materials. The systemsuccessfully separated the emulsion into a re-coverable DOP stream and a wastewater suitablefor discharge to the wastewater treatment facil-ity.

l Unocal: The unit completed a series of demon-strations at Unocal’s Parachute Creek Colorado,facility. Among the wastes successfully runwere samples of shale-oil wastes, drilling muds,and other process and refinery wastes. High rc-covery of good-quality oil was obtained fromshale-oil wastes. Drilling mud wastes weretreated to the standards required for land dis-posal.

l United Cresote NPL Site: A field treatabilitystudy was completed for the Texas Water Com-mission, a Superfund Site in Conroe, Texas. The

objective of this study was to evaluate the effec-tiveness of solvent extraction for remediation ofsoil contaminated with creosote. PAH concen-trations in the soil obtained from the capped areawere reduced from 2,879 ppm to 122 ppm, dem-onstrating that 95-percent reductions were pos-sible.

CF Systems has collected bench-scale test data for awide range of organic pollutants contained in wastewaters,sludges, and soils. Carbon dioxide was used as a solvent toremove volatile and semivolatile organics from wastewa-ters and groundwaters. Extraction efficiencies rangedfrom 95 to 99.99 percent for 24 pollutants that ranged inconcentrations from 0.4 ppm to 520 ppm, as shown inTable 3-l. Propane was used as a solvent to extractpolyaromatic hydrocarbons (PAHs) andbenzene, ethylben-zene, toluene, and xylene from refinery sludges, APIseparator sludges, and contaminated soils. Extractionefficiencies ranged from 80 to 99 percent for concentra-tions that ranged from 0.3 ppm to 1930 ppm, as shown inTable 3-2.

EconomicsThe cost of installing and operating a commercial-

scale system depends primarily on (1) waste characteris-tics that affect the need for pre- and post -treatment, (2) theamount of waste to be treated, (3) the degree of treatmentrequired, and (4) the percentage of time that the system isactually operational. Soil pretreatment includes water ad-dition, large solids removal, and possibly heat addition,while post-treatment includes dewatering. The amount ofwaste at a site affects equipment sizing, the total amount oftime required to clean up a site, and life-cycle costs. Thedegree of treatment required affects operating costs sincelonger residence times of the waste in the equipment areneeded to achieve higher pollutant removals. The percent-age of time that the unit is fully operational can have asignificant effect on the unit treatment costs, in terms ofcost per ton.

CF Systems sized and costed two soil treatment unitsfor PCB removal from New Bedford Harbor sediments.The objective waste estimate cleanup costs at NewBedfordusing the CF Systems technology and to illustrate thedesign approach used to scale-up the technology for a com-mcrcial application. The estimate was based on dataobtained for PCB extraction from New Bedford Harborsludge using the pilot-scale unit and on a commercialdesign of the unit at the Texaco, Port Arthur facility. Thebase case addressed a large mass of sediment (880,000cubic yards) at a 580 ppm PCB concentration. Treatmentwould be conducted over an eight-year period to producesediment concentrations of 50 ppm at a rate of 500 tons/day

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raw feed. Pre- and post-treatment are required to reduceviscosity and raw feed solids content. Total treatment costis estimated at $148/ton (1989 dollars) of which one-thirdis associated with pre-and post-treatment. The hot spotcorresponds to treatment of a small mass (63,000 tons) at10,000 ppm PCB concentration over a one-year timeframe. The treated sediment concentration goal is 10 ppmPCB. Total treatment costs are $447/ton (1989 dollars), ofwhich approximately one-third are pre- and post-treatmentcosts.

The economic analysis addressed costs directly re-lated to the extraction unit as well as site-specific costs.Costs were categorized as fixed facility, extraction unit,pre- and post-treatment, contingency, and project manage-ment costs. CF Systems assigned an accuracy of plus orminus 20 percent to their cost estimates. However, indus-try experience with innovative technologies has shownthat costs could range from plus 50 percent to minus 30percent. The uncertainty associated with the estimatedcosts is believed to be low since CF Systems incorporates“off-the-shelf’ equipment into their designs. CF Systemsbased their estimates on a unit construction for use at aTexaco refinery and on designs specific to New Bedford.

The greatest source of uncertainty associated with CFSystems’ cost estimates is their assumption of the percentof time that the unit will be on-stream. CF Systemsassumed an on-stream factor of 85 percent; however, this

was not demonstrated by operating the PCU-20 at NewBedford. CF Systems claimed that material-handlingproblems associated with the operation of a pilot unitwould be minimized with acommercial unit. CF Systemsmust demonstrate that an 85-percent on-stream factor isachievable for a commercial unit. EPA intends to evaluatethe vendors’ claim for the 85-percent on-stream factor byobserving the performance of a commercial unit at a futuredate. EPA will also observe and evaluate materials han-dling associated with the operation of a full-scale unit toverify mitigation of the problems experienced with thepilot unit.

CF Systems also offers a wastewater treatment unitthat differs from the soils treatment unit in the types ofsolvent and equipment used. Liquefied carbon dioxide isused instead of propane or butane. CF Systems hasdelivered a wastewater treatment unit to a Clean Harbors,Inc., facility in Baltimore. Although CF Systems reportstypical wastewater treatment costs of 5 to 15 cents pergallon, the cost for treating wastewater at the Baltimorefacility is 15 cents per gallon, which is approximately $35per ton. Costs associated with CF Systems’ wastewatertreatment unit are lower than those associated with the soilstreatment unit for two reasons. First, the equipment usedin the design differs. Second, no pre- or post-treatment isrequired since solids content and viscosity are low andtemperatures are moderate.

5

Section 2Introduction

2.1 The SITE ProgramIn 1986, the EPA’s Office of Solid Waste and Emer-

gency Response (OSWER) and Office of Research andDevelopment (ORD) established the SITE Program topromote the development and use of innovative technolo-gies to clean up Superfund sites across the country. Now inits third year, SITE is helping to provide the treatmenttechnologies necessary to implement new Federal andStatecleanup standardsaimedatpermanentremedies. TheSITE Program is composed of three major elements: theDemonstration Program, the Emerging TechnologiesProgram, and the Measurement and Monitoring Technolo-gies Program.

The major focus has been on the Demonstration Pro-gram, which is designed to provide engineering and costdata on selected technologies. EPA and developers par-ticipating in the program share the cost of the demonstra-tion. Developers are responsible for demonstrating theirinnovative systems at chosen sites. usually Superfundsites. EPA is responsible for sampling, analyzing, andevaluating all test results. The result is an assessment of thetechnology’s performance, reliability, and cost. This infor-mation will be used in conjunction with other data to selectthe most appropriate technologies for the cleanup of Super-fund sites.

Developers of innovative technologies apply to theDemonstration Program by responding to EPA’s annualsolicitation. EPA also will accept proposals at any timewhen a developer has a treatment project scheduled withSuperfund waste. To qualify for the program, a newtechnology must be at the pilot or full scale and offer someadvantage over existing technologies. Mobile technolo-gies are of particular interest to EPA.

Once EPA has accepted a proposal, EPA and thedeveloper work with the EPA regional offices and Stateagencies to identify a site containing wastes suitable fortesting the capabilities of the technology. EPA preparcs adetailed sampling and analysis plan designed to thor-oughly evaluate the technology and to ensure that theresulting dataarereliablc. The duration of a demonstrationvaries from a few days to several months, dcpcnding on thelength of time and quantity of waste ncedcd to a s s e s s thetechnology. After the completion of a technology dcmon-

stration, EPA prepares two reports, which are explained inmore detail below. Ultimately, the Demonstration Pro-gram leads to an analysis of the technology’s overall appli-cability to Superfund problems.

The second principal element of the SITE Program isthe Emerging Technologies Program, which fosters thefurther investigation and development of treatment tech-nologies that are still at the laboratory scale. Successfulvalidation of these technologies could lead to the develop-ment of a system ready for field demonstration. The thirdcomponent of the SITE Program, the Measurement andMonitoring Technologies Program, provides assistance inthe development and demonstration of innovative meas-urement technologies to better characterize Superfundsites.

2.2 SITE Program ReportsThe analysis of technologies participating in the

Demonstration Program is contained in two documents,the Technology Evaluation Report and the ApplicationsAnalysis Report. The Technology Evaluation Reportcontainsacomprehensivedescriptionofthedemonstrationsponsored by the SITE program and its results. This reportgives a detailed description of the technology, the site andwaste used for the demonstration, sampling and analysisduring the test, and the data generated.

The purpose of the Applications Analysis Report is toestimate the Superfund applications and costs of a technol-ogy based on all available data. This report compiles andsummarizes the results of the SITE demonstration, thevendor’s design and test data, and other laboratory and fieldapplications of the technology. It discusses the advan-tages, disadvantages, and limitations of the technology.Costs of the technology for different applications areestimated based on available data on pilot- and full-scaleapplications. The report discusses the factors, such as siteand waste characteristics, that have a major impact on costsand performance.

The amount of available data for the evaluation of aninnovative technology varies widely. Data may be limitedto laboratory tests on synthetic wastes, or may includeperformance data on actual wastes treated at the pilot or fullscale In addition, there are limits to conclusions regarding

7

Superfund applications that can be drawn from a singlefield demonstration. A successful field demonstrationdoes not necessarily ensure that a technology will bewidely applicable or fully developed to the commercialscale. The Applications Analysis attempts to synthesizewhatever information is available and draw reasonableconclusions. This document wilI be very useful to thoseconsidering the technology for Superfund cleanups andrepresents a critical step in the development and commer-cialization of the treatment technology.

2.3 Key ContactsFor more information on the demonstration of the CF

Systems technology, please contact:

1. Regional contact concerning the New BedfordHarbor. MA, site:

Mr. Frank CiavattieriWaste Division (HPLEANl)USEPA, Region 1John F. Kennedy BuildingRoom 2203Boston, MA 02203617-565-3715

2. EPA project manager concerning the SITE demon-stration:

Laurel StaleyUSEPARisk Reduction Engineering Laboratory26 W. Martin Luther King DriveCincinnati, OH 45268513-569-7863

3. Vendor concerning the process:

CF Systems CorporationMr. Christopher Shallice, x 158Mr. Thomas C. Cody, Jr., x 162140 Second AvenueWaltham, MA 02154-0100617-890-1200

8

Section 3Technology Applications Analysis

3.1 Overall Technology ApproachCF Systems’ organics extraction technology physi-

cally separates organic contaminants from the inorganiccomponentsofa wastematrix. Thisseparationandvolumereduction technology allows the organic contaminants tobe ultimately disposed in a more cost-effective manner.For example, the cost of incinerating a large volume of oil-laden soils can be minimized by separating the oils from thesoils, then incinerating only the small volume of oils. Anyinorganic contaminants, such as heavy metals, that remainin the treated product may require additional treatment.The SITE Program showed, however, that the organicsextraction process did not affect the physical or chemicalcharacteristics of the metals contained in the sediments.Metals were notextracted by the solvent and remained withthe treated sediments. The presence of metals in thesediments did not affect the extraction of organics. Fur-thermore, the metal leaching characteristics, as determinedby the EP Tox procedure, were not affected by the process.The extraction process is not an ultimate disposal method,but it is a significant organics separation technique that canmake ultimate disposal more economic.

Applications of the CF Systems organics extractiontechnology depend on the physical/chemical characteris-tics of the waste, its volume, and the degree of pollutantremoval required. Waste characteristics determine thetype of solvent to be used. For example, liquefied propane,or a mixture of propane and butane, is used to extractorganics that are not very soluble in water, such as PCBsand PAHs. These hydrophobic organics tend to sorb toparticulate matter present in soils and sludges. CFSystemshas shown in the laboratory and in pilot-scale demonstra-tions that propane and butane are effective extractionsolvents forremoving theseorganics from soils and sludges.Carbon dioxide is used by CF Systems to extract watcr-soluble organics from wastewater and groundwatcr sincecarbon dioxide seeks polar materials in water, is nontoxic,and has favorable engineering properties. Carbon dioxideused in the process can be maintained near its thermody-namic critical point, the operating region where the liquidmakes a phase transition to a gas. At this point, carbondioxide has the viscosity of a gas, mixes easily with waste,and has the solvent properties of a liquid. Waste character-

istics also determine the nature and extent of pre- and post-treatment that may be required. For example, dry solidsrequire water addition to create a pumpable slurry, and theultimate disposal of treated wastes with water added mayrequire dewatering.

Waste characteristics, waste volume, and the degreeofpollutantremoval significantly affect system design. CFSystems has designed standard modular systems for differ-ent markets and applications. For sludge treatment units,the capacity range is about 12 to 250 tons per day. Forwastewater treatment units, the capacity range is about 5 to150 gallons per minute. The units are constructed ofcarbon or stainless steel and can be modularized, shipped,and field assembled. If high throughput capacities arerequired, the modular units can be placed in parallel. Ifhigh extraction efficiencies are necessary, several units canbe arranged in series. As a result of this approach, a numberof specific units have been developed and designed.

The soils treatment units are designed to process highsolids sludge feeds and contaminated soils. They containextractors and separators designed to facilitate the treat-ment of oily solids typical of petroleum sludges and wastematerials found in refinery impoundments requiring reme-diation. The systems included in this product series are:

.

.

.

9

PCU-50: This system, designed to process amaximum of about 12 tons per day, is a standardproduct for refinery sludges regulated by EPA’sRCRA land disposal ban and sludges found at pitbottoms, as well as oil- and PCB-contaminatedsoils and silts. The system is modular and will bedesigned for installation into confined spaces soas to be readily integrated into existing opera-tions.PCU-200: This system, designed to process amaximum of about 50 tons per day, is a standardproduct for refinery sludges regulated by EPA’sRCRA land disposal ban and sludges found at pitbottoms, as well as oil- and PCB-contaminatedsoils and silts. The system is mounted on two flatbed trailers, and can be demobilized-remobil-izcd at a new location in several days.PCU-500: The PCU-500 is similar to the PCU-200 design, but with incrcased extractor capacity

to provide for throughputs up to about 125 tonsper day. Although the cost increment over thePCU-200 is relatively small, the PCU-500 re-quires somewhat longer time for mobilizationand demobilization vs. transportable modules. Itis designed for remediation of fixed base usewhere site relocation is infrequent.

l PCU-1000: This system. with a 250-ton-per-daynominal capacity, is intended for large remedia-tion jobs where onsite time is projected to be oneyear or more at a single location. Modular andtransportable, but with multiple modules, thissystem requires several weeks for mobilizationand demobilization.

The LL series is designed for the extraction of dis-solved or emulsified organics in water streams. Solids areusually not present at a significant level in these streams.If present, solids must be reduced to the 2 to 3 percent levelby pretreatment. Organics content of the feed can range ashigh as 30 to 50 percent and removal efficiencies canexceed 99.9 percent. Applications for the LL series includea wide range of organic wastewaters.

3.2 Technology EvaluationThe most extensive evaluation of the CF Systems

technology was conducted for a soils treatment unit as partof the SITE tests at New Bedford. Qualitative evaluationsare also available for similar units tested by CF Systems atother locations. CF Systems has reported the results fromextensive bench-scale tests conducted with either propaneor carbon dioxide used as the extraction solvent.

CF Systems initially assesses a clients’ waste by con-ducting bench-scale tests in the laboratory to determine ifthe organic constituents will solubilize in the liquefiedsolvent. CF Systems is also able to use rules-of- thumb toroughly estimate the number of processing stages thatmight be required to achieve a desired extraction effi-ciency. In the laboratory, the waste can be observed todetermine if large particles are present that could clogsystem hardware and to determine if water should be addedto make the waste pumpable. If the bench-scale tests showthat the organic constituents can be separated from thewaste, then pilot-scale tests are run. Wastewaters contain-ing organics that are amenable to extraction by liqucfiedcarbon dioxide are tested with a pilot-scale unit located inCFSystems’ Massachusetts laboratory. Soils, sludges, andother semisolids that are effectively treated by liquefiedpropane or a propane/butane mix are tested in theficld withCF Systems’ trailer-mounted unit. Based on successfulfield demonstration results, clients have placed orders forsoils and wastewater units.

Bench-Scale TestsCF Systems has conducted numerous bench-scale

tests for contaminated wastewaters, groundwaters, sludges,and soils. Table3- 1 shows extraction efficiencies achievedfor removing various pollutants from wastewaters andgroundwaters. Liquefied carbon dioxide was used toreducecontaminant concentrations that ranged from 0.4 to520 ppm by more than 95 percent for 23 volatile andsemivolatile organics. Liquefied propane was used toextract organics from samples of refinery sludges, separa-tor sludges, and contaminated soils. Table 3-2 showsextraction efficiencies for the separation of volatile andsemivolatile organics that range in concentration from 0.3to 1,930 ppm. Extraction efficiencies ranged from 80 to99.9 percent with a median of 97 percent. The bench-scaledata demonstrate that a wide range of organics can beseparated from aqueous and semisolid wastes; however,the extraction of organics from semisolids is somewhatless efficient than that of aqueous wastes.

Pilot-Scale TestsThe SITE program tests on the soils treatment unit in

New Bedford produced analytical and operating data usedfor the evaluation system performance, operating condi-tions, and equipment and material handling problems. Theperformance of the unit was evaluated in terms of extrac-tion efficiency and a mass balance. Extraction efficiencyper pass was defined as the input PCB concentration minusthe output PCB concentration divided by the input PCBconcentration(multiplied by l00 percent). Aninventoryofsystem inputs and outputs was established and evaluatedfor total mass, total solids, and total mass of PCBs. Fivetests were run. Test 1 was a shakedown test and Test 5 wasa decontamination test. Results of these tests and evalu-ations are summarized as follows:

PCB removal efficiencies of 90 percent andgreater, were achieved for sediments containingPCBs ranging from 350 to 2,575 ppm. A highremoval efficiency was achieved after severalpasses, or recycles, of treated sediments throughthe unit. The low concentration for PCBs thatwas achieved was 8 ppm.Extraction efficiencies greater than 60 percent

were achieved on the first pass of each test. Laterpasses of treated sediments through the unitrcsulted in efficiencies ranging from zero to 84percent. This wide range was due to solids re-tention in the system. Solids retained in thesystem cross-contaminated treated sediments thatwere recycled. (Recycling was necessary tosimulate the performance of a full-scale com-mercial system. CF Systems’ full-scale designsdo not include recycling since additional extrac-

10

Table 3-1. Bench-Scale Test Results For Wastewaters and GroundwatersRaw Waste

Concentration(parts per million.)

Extraction.fficiency (1)

Acetone 82 99.7Acetonitrile 355 99.0Acrylonitrile 275 99.9Benzene 22 99.9bis (2-ethylhexyl) phthalate 4 972-Butanone 520 99.96Chloroform 180 99.991,2-Dichloroethane 180 99.992,4-Dimethylphenol 0.9 97.7Dimethyl Phthalate 0.400 95lsophrone 2.9 99.3Methylene Chloride 35 99.98P-Methylphenol 0.4 95Napthalene 0.400 95Nitrobenzene 52 99.96PCB-1242 3.1 95Phenol 4 95Tetrachloroethane 20 99.97Tetrahydro Furan 6 96.1Trichloroethane 77 99.991 ,1 ,1-Trichloroethane 22 99.97Toluene 44 99.98

Notes:(1) Bench-scale measurements, not necessarily an equilibrium limitation. Extraction efficiency calculated as percent of

pollutant removed.

tion stages and longer processing times are in-volved.) Some solids appear to have been re-tained in equipment dead spaces and intermit-tently discharged during subsequent passes.

l A mass balance was not established for PCBs. Atotal of 157 grams of PCBs were fed to the unit.Of the total, 80 grams were accounted for insystem effluents. Decontamination washes pro-duced an additional 169 grams. The sum ofeffluents and decontamination washes was,therefore, 101 grams greater than that fed to theunit.This large difference may be due, in part, tolimitations of the analytical method. PCB ana-lytical Method 8080 precision criteria estab-lished for this project were plus or minus 20percent and accuracy criteria were plus or minus50 percent. In addition the mass balance calcu-lation was dominated by the Test 4 feed concen-tration. Therefore, error associated with theTest 4 feed sample could also be a source of thePCB mass imbalance. Another possibility is

contamination of the PCU from prior use at othersites. However, CF Systems has not p r e v i -ously fed materials to the unit that were knownto contain PCBs.

l A good mass balance was established for totalmass and solids through the system. A total of3-l/2 tons of solidsand water were fed to the unitduring Tests 2.3, and 4; of the total, 96 percentwas accounted for in effluent streams. A total of789 pounds of solids was processed. Of the total,93 percent was accounted for in effluent streams.The slight imbalances, 4 and 7 percent, are at-tributed to the inaccuracy of the weighing device(1 percent), sample error, and accumulation ofmass in system hardware.

l Metals were not expected to be removed from thesediments, and were not removed during theextraction. Extraction Procedure Toxicity (EPTox) test results indicate that metals did notleach from either treated or untreated sediments.Characteristics of the sediments, with respect tothe EP Tox test, werenotaltered bythetreatment

11

Table 3-2. Bench-Scale Test Results for Sludges and Soil

Average Feed Concentration

(PPM)Refinery Separator

SludaeOil and Grease

Volatiles

32.2

Sludae5.68

w10.5

BenzeneEthyl BenzeneTolueneXylenes (Total)

Semivolatiles

370 23.8 __

<0.3 25.0 __

390 13.4 _ _1160 106.3 __

Acenophthylene 714Acenaphthene 1930Anthracene 667Benzo(A)pyrene _ _

Bis(2-Ethylhexyl)phthalate __

Chrysene <35Fluoranthene 889Fluorene _ _

Naphthalene <35Phenanthrene 1360Pyrene <35

____

27.71.94.76.4

13.941.527.7

6.9

95 91 to 9932 96 to 99

143 90 to 99_ _ 82__ 85__ 93 to 97

34.0 94 to 98__ 97__ 97 to 99

56.0 97 to 9938.0 90 to 95

process. Copper and zinc concentrations weretypically greater than 1,000 ppm, while chro-mium and lead ranged from 500 to 1,000 ppm.

l The decontamination procedure showed thatPCBs were separated from the sediment. Mostof the PCBs were contained in extract subsys-tem hardware. Of the 8 1 grams of PCB fed to theunit during Tests 2,3, and 4, only 4 grams re-mained in the final treated sediments. Subse-quent decontamination of the PCU with a tolu-ene wash showed that some PCB had accumu-lated in system hardware. However, 91 percentof the PCBs contained in decontamination resi-dues were found in extract subsystem hard-w a r e .

ratio; and extractor pressure and temperature. The unitgenerally performed as CF Systems predicted, althoughsome deviations from the planned specifications did occur.An evaluation of operating conditions is summarized asfollows:

l A quality assurance/quality control (QA/QC)review showed that analysis data of PCBs insediments for Tests 1 through 5 were sufficientlyaccurate and precise for an engineering assess-ment of the efficiency of this demonstration.

Operating conditions essential to the efficient per-formance of the PCU were manually controlled and moni-tored during Tests 2, 3, and 4. The operating conditionsincluded feed temperature, particle size, flow rate, pH, andsolids content; solvent flow rate and solvent/feed mass

.

.

.

12

Feed flow rates and extractor pressures werecontrolled throughout the tests within specifiedranges. Feed flow rates ranged from 0.6 to 1.4gpm. Extractor pressures ranged between 190and 290 pounds per square inch guage (psig).During Test 2, feed temperatures for the last 4passes were 10 degrees F lower than the mini-mum specification, 60 degrees F. Decreasedextraction efficiency, which was apparent dur-ing this test, could have been related to lowfeed temperatures. Sustained low temperaturescould have the effect of seriously reducing ex-traction efficiency in a full-scale commercialsystem.Solvent flow fluctuated as much as 75 percentabove and below the nominal flow rate, 12 lb/min. In Test 2, Pass 1, this caused the solvent-to-feed ratio to fall below specifications. Thesolvent flow fluctuations could affect the extrac-tion efficiency in a full-scale system, since less

Typical

Percent5eductiofi

93 to 98

9980 to 99

9999

solvent would be available to extract organicpollutants from the feed soil.

l Specifications for maximum particle size, one-eighth inch, were met by sieving sedimentsthrough a screen. This was necessary to pre-vent damage to system valves. Less than 1percent of the sediment particles were greaterthan one-eighth inch.

l Specifications for maximum viscosity, 1,000centipoise (cP), were met by adding water to-form a pumpable feed mixture. Feed viscositiesranged from 25 to 180 cP. However, added waterincreased the mass of waste by about 33 percent.

l Solids contents ranged from 6 to 23 percent andfell below the minimum specification, 10 per-cent, after the fourth pass of Tests 2 and 4. A 10-percent minimum specification was set merelyto ensure that the technology would be demon-strated for high solids content feeds.

l EPA and the developer will address correctivemeasures for operational controls and materialhandling issues. However, these measures arenot the subject of this report.

Equipment and system material handling problemsoccurred, although some problems were anticipated.Problems included the following:

l Internal surfaces of extractor hardware and pip-ing collected PCBs as evidenced by mass bal-ances for PCBs and subsequent washes of theunit with a refined naphtha fuel and later withtoluene. The washes recovered accumulatedPCBs as well as oil and grease.These accumulations of organics are believed tobe the result of the short duration of the tests andthe small volume of organics contained in thefeed sediment, relative to the volume of the ex-traction system hardware. PCBs are soluble inoil and grease, which is believed to coat theinternal surfaces of system hardware. Continu-ous operation of the unit has resulted in continu-ous discharge of extracted organics at otherdemonstrations of the technology.

l The unit intermittently retained and dischargedfeed material solids. This is the result of therelatively small volumes that were batch fed tothe unit. The unit was designed for continuousoperation, not short-term tests. In addition, only50 to 150 gpd were run through the PCU, whichwas designed to handle up to 2,160 gpd. There-fore, some solids may have been retained inequipment dead spaces and intermittently dis-charged during subsequent passes.

Solids were observed in extract samples, whichwere expected to be solids free. This indicatespoor performance or failure of the cartridgefilter. An alternative type of filter should beinvestigated by the developer.Extractor and treated sediment hardware con-tained organic sludge from prior use of the unitat a petroleum refinery. Presence of the petro-leum residuals prevented complete interpreta-tion of datacollected for oil and grease and semi-volatile organics.Low-pressure dissolved propane caused foam-

ing to occur in the treated sediment producttanks. This hindered sample collection andcaused frequent overflow of treated sediment toa secondary treated sediment product tank. CFSystems states that design of a commercial-scaleunit will allow release of propane entrained inthe treated sediment and eliminate the foaming.However, EPA cannot verify the claims on thisissue until it evaluates system operability for afull-scale commercial unit.

CF Systems reports successful demonstration of itsmobile soils treatment unit at petroleum refineries, petro-chemical, and TSD facilities throughout North America.including:

. Texaco.Port Arthur, Texas

. Tricil, Toronto, Canada ,

. Chevron, Salt Lake City, Utah

. Exxon, Baton Rouge, Louisiana

. Chevron, Perth Amboy, New Jersey

.- Unocal, Parachute Creek, Colorado

. BASF, Kearny, New Jersey

. United Creosote, Conroe, Texas

. Petro-Canada, Montreal, Canada

The unit had its initial startup at Texaco’s Port Arthurrefinery in September 1987. Feeds run through the unitincluded material from a clay pit, ditch skimmer sludge,and tank bottoms. The resulting treated solids productstreams were analyzed by Texaco, and representative re-sults are shown in Table 3-3. Levels of individual compo-ncnts, including benzene, ethylbenzene, tolucne, xylene,and phenanthracene bettered the existing BDAT stan-dards. In many cases these levels were found to be belowdetection limits. Following the demonstration, Texacoawarded CF Systems a contract to provide a commercialunit to remcdiate 20,000 cubic yards of API separatorsludges and ditch skimmer wastes.

13

The unit also operated at the Petro-Canada refinery inMontreal for a six-week period. During this time, the unitsuccessfully processed 14 different feed types, rangingfrom API separator sludges to contaminated solids. Theunit consistently achieved organic removal levels betterthan existing BDAT standards.

A series of demonstration tests was run at TricilCanada’s TSD facility in the Province of Ontario. Thefeeds processed included API incinerator sludge, paintwastes, synthetic rubber process waste, and coal tar wastes.The unit affected a large-volume reduction of the materialprocessed and the level of volatile organics was reducedsuch that disposal of the material in a local Canadianlandfill was acceptable.

Generic solvent extraction and incineration technolo-gies were named by EPA as BDAT for listed petroleumrefinery hazardous wastes (40 CFR 261.32 KO48-K052).CF Systcms’and other developer’s performance data, frompilot-scale tests, were included in the basis for settingperformance specifications for treatment of these wastes.

The MDU completed a treatability study for the TexasWater Commission in conjunction with Roy F. Weston atthe United Cresoting Superfund Site in Conroe, Texas.The objective of this study was to evaluate the effective-ness of solvent extraction for remediation of soil contami-nated with creosote. PAH concentrations in the soilobtained from the capped area were reduced from 2,879ppm to 122 ppm, demonstrating that reductions greaterthan 95 percent were possible. Representative results fromthis study are shown in Table 3-4.

Full-Scale ApplicationsOperating, performance, and cost data are not avail-

able for a full-scale system. EPA intends to collect thesedata at a later date. Over the past 18 months, CF Systems’commercial activity has consisted of the following majorefforts:

l In March 1989 the first of the Company’s 50-tons-per-day unit was shipped to Star’s PortArthur, Texas, refinery (Texaco) for a 14-monthfull-scale commercial cleanup of oily s 1 u d g ewastes. Under this contract, the soils treatmentunit will treat about 20,000 tons of sludge toproduce cleaned solids, treatable water, and oilfor recycle. This unit became operational inJuly 1989.

l A custom-built, 60-tons-per-day soils treatmentunit was shipped to ENSCO’s El Dorado, Arkan-sas, incineratorfacility in November 1988. Since

.

.

3.3

ENSCO is reorganizing their El Dorado opera-tion the unit has not been placed on line; how-ever, the unit will extract organic liquids from abroad range of hazardous waste feeds sent to thesite for incineration. The extracted liquids willbe used as incinerator secondary combustionfuel, while the residues, reduced in heat content,will allow higher incinerator throughputs forENSCO.A 20-gpm wastewater treatment unit was sold toClean Harbor, Inc. It is expected to be installedat a TSD facility in 1989 in Baltimore, MD.CF Systems has established performance speci-fications for the LL-series wastewater treatmentunit. A 99-percent extraction efficiency is speci-fied for 2,000 ppm of trichloroethylene in wastewaters. A 97-percent extraction efficiency isspecified for 12,000 ppm of methyl isobutylketone in wastewater.

Waste Characteristics and OperatingRequirements

The SITE program tests provided waste characteriza-tion and system operating data for the propane-based pilotunit, which is designed for the treatment of soils andsludges. CF Systems’ wastewater treatment unit was not asubject of the SITE tests; therefore, no discussion of thatunit appears in the sections that follow. However, someaspects of system operation and economics for the twotechnologies are similar. Details on the two technologiesare presented in Appendix A - Process Description.

Feed Material SpecificationsPhysical characteristics of wastes fed to CF Systems’

sludge and soils treatment technology must fall within theranges shown in Table 3-5. Solids greater than 3/16 inchmay clog process valves and piping. Feed pH must bemaintained between 6 and 10 to protect process equipmentfrom corrosion. The feed must be pumpable in order toflow through the system under pressure; therefore, amaximum viscosity of 5,000 c P is established. Viscous ordry materials are typically slurried with water, althoughthis practice increases the volume of waste and may requiredcwatering. If the feed is less than 60 degrees F, freezingmay occur in the extractor. Conversely, feeds greater than120 degrees F may cause solvent vaporization. CF Sys-tcms’experience has shown that extraction efficiencies arehigh when feed solids and water contents fall within thewide ranges shown in Table 3-5.

If the technology was considered for a full-scalecleanup at New Bedford Harbor, pretreatment would bercquircd lo bring the sediments within the required physi-

14

Table 3-3. Texaco, Port Arthur Performance Data

BDATParameter Levels

(mg/Kg)

Water(l) -- 60.5Solids( 1) -- 22.3

Oil(l) __

Total Oil --& Grease( 1)

Benzene (B ) 9 .5 9.6Ethylenzene 67 13Toluene 9.5 16Xylenes 63 <0. 1

Fluorene --Naphthalene --2Methyl --

NapthalenePhenanthrene 7.7

CLAY PIT AREA(l)Feed

(mg/Kg)

TreatedSolids

(mg/Kg)

Water Feed

(mg/L) (mg/Kg)

17.2

__

__

210300

__

_ ___

__

1.9

<0. l(3)<0.1<0.1

<0.01

__

<5.3<5.3

__

___-

__

-_

<O.Ol<O.Ol<0.01<2.0

_ _

__

__

SLUDGE(l)Treated

Solids

(mg/Kg)

62 __

32 _ _

6 __

__

<2.04.0<2.0<2.0

_-

<50-_

31

3.6

<2.0<0.1<O.l<O.l

__

<3.3__

<3.3

TCLP Feed

(mg/L) (mg/Kg)

_-_ _

-_

__

<0.01<O.Ol<O.Ol<O.Ol

-_

__

_ _

5733

10

__

13.720.254.475.9

__

45__

30

SLUDGE( 1) DITCH SKIMMER(l)Treated

Solids

(mg/Kg)

Feed

(mg/Kg)

Treated TCLPSolids

(mg/Kg) (mg/L)

_ ___

__

1.0

<2.0<O.l<O.l<O.l

__

<3.3__

<3.3

5335

12

__

5.1135271

9.316.5__

18.6

__ .___ __

__

0.7 --

<0.1 <O.O1<O.l <0.01<0.1 <0.01<0.1 <0.01

<0.20 --<0.20 --

__ __

<0.20 --

Notes: (1) Water, solids, oil, and total oil and grease reported as percent by weight.(2) TCLP is the Toxicity Characteristic Leaching Procedure.(3) < indicates less than the detection limit shown.

Table 3-4. United Creosote Superfund SITE Performance Data

CompoundFeed Treated

Soil CMGiKGl Soil IMG/KGl

Acenaphthene 360 3.4Acenaphthylene 15 3.0Anthracene 330 8.9Benzo(A)anthracene 100 7.9Benzo(A)pyrene 48 12Benzo(B)fluoranthene 51 9.7Benzo(G,H,I)perylene 20 12Benzo(K)fluoranthene 50 17Chrysene 110 9.1Dibenzo(A,H)anthracene ND 4.3Fluoranthene 360 11Fluorene 380 3.8Indeno( 1,2,3-CD)pyrene 19 11Naphthalene 140 1.5Phenanthrene 590 13Pyrene 360 11Total (MG/KG) 2879 122.6

Notes: Mg/Kg on a dry weight basis. ND indicates not detected.

Table 3-5. Sludge and Soil Feed Requirements

Minimum

Solids Size -

pH 6Viscosity (centipoise) 0.5

Feed Temp. (degrees Fahrenheit) 60

Feed Solids (percent by weight) 0

Water (percent by weight) 20

Organics (percent by weight) 1

Nominal Maximum

l/8 3/16 inch__ 10

10 5,00070 120

30 50

40 90

20 90

16

cal specifications. Less than one percent of the NewBedford Harbor sediments were greater than 3/16 inch;nonetheless, sieving through screens was required to removeoversize particles. The sediments were also viscous;therefore, water was added to ensure pumpability. On oneday during the SITE tests, ambient temperatures fell andcaused the feed to drop below 60 degrees F, which mayhave affected extraction efficiency. A full-scale applica-tion would require sieving of untreated sediments, wateraddition, and heat addition. Cost-effective disposal oftreated sediments would require dewatering to minimizedisposal volumes. In turn, dewatering effluent wouldrequire treatment at a publicly owned treatment works orby an onsite waste water treatment system. CF Systems’experience has shown that oversized solids removal issometimes required and that water addition is necessary fordry solids.

The technology is capable of treating the widerangeofwaste matrices found in most waste handling situations.The ranges specified for viscosity, feed solids water con-tent, and organics content are very broad. The rangesspecified for solids size, pH, and temperature are alsobroad but these parameters are more likely to exceed inputspecifications. However, off-the-shelf technology is avail-able to bring off-spec feeds within CF Systems’ requiredoperating ranges.

Utilities and LaborUtility requirements for the technology include (1)

electricity, (2) cooling water maintained at 60 to 80degrees F, (3) commercial-grade propane and/or butane,and (4) nitrogen to pressure test the equipment duringstartup. The amounts of electricity, propane, and butaneused during the SITE tests were not significant. In addi-tion, the unit wassatisfactorilypressure-tested. Theamountof noncontact cooling water, 5 gpm, was significant on thissite and should be considered in the design of any futureapplication.

All CF Systems’ units are mobile and can be trans-ported on public roads. The modular design of the unitsmitigates the need for field fabrication. The sizes of CFSystems treatment modules are limited by the need fortransportability on public roads. A firm, level foundationis needed and the area required for the 200-ton-per-daycommercial-sized unit, including ancillary skids, is about4,000 square feet. An estimated 2,000 hours of labor arcrequired to install the system. A site engineer, a sitemanager, and additional labor and safety equipment wouldalso be required. Space for safe storage of the liquefiedsolvent is also necessary. A large commercial-scale unitcan be operated continuously by four or five people pershift (two or threeunit operators one supcrvisor, and apre-/post-treatment operator). Three such teams, each operat-

ing on an 8-hour shift, can be used to operate the unit on a24-hours-per-day, 7-days-per-week basis.

3.4 Materials Handling RequirementsPre- and Post-Treatment

Requirements for pre- and post-treatment of wastesare site specific. The SITE program experience, at NewBedford, provided an example of the types of materialhandling needs that must be addressed. Pretreatment ofNew Bedford sediments would be required to remove par-ticles greater than 3/16 inch, to decrease viscosity, and tomaintain feed temperature. In addition, the feed consis-tency should be homogeneous to minimize process uncer-tainty and to improve control of flowrates. Hence, solidsremoval, water addition, mixing, and storage are importantpretreatment steps. The addition of water and heat can beincorporated into either the solids removal or the mixingoperations. Sufficient storage capacity is also importantfor those operating days when treatment goals are not beingmet because of equipment failure or slug loads of highconcentration wastes.

A sieving and screening method is the most appropri-ate pretreatment method for New Bedford Harbor sedi-ments, based on experience during the demonstration test,and was thus selected for this application. Vibratingscreens are more widely used than any other screen typesbecause of their larger capacity per unit screen area andtheir higher efficiency. However, wet or sticky materialstend to blind the screen; therefore, wet screening withsprays can be used to discourage blinding.

Manual or automated high-pressure water spraying isassumed adequate to treat oversized solids. These coarsesolids would be disposed of with fine-grained sedimentstreated by the CF Systems technology. Spray water wouldbe collected and reused. Common mixing equipment andstorage tanks are adequate to provide a homogeneoussource of feed for the CF Systems technology. Heat can beprovided by steam addition.

Post-treatment must beconsidered for the two productstreams generated by this process. The extract contains theconcentrated organics and the treated sediments containthe water and solids. Provisions for extract containment,handling, storage, and transport off site would have to bemade. The volume of treated sediments would be greaterthan that of the untreated if water is added during pretreatmerit; dewatering could be necessary However, dewater-ing effluent could be reused in the pretreatment operation.Thus, wastewalcr treatment costs would be minimized.Treated sediments would be disposed of in either a Re-source Conservation and Recovery Act (RCRA) approvedlandfill or a confined disposal facility located in the harbor.

17

Materials handling requirements would bc integratedwith the CF Systems technology for applying the technol-ogy to a New Bedford Harbor cleanup. The overall processwould consist of the following steps:

Step 1

Step 2.

Step 3.

Step 4.

Step 5.

Step 6.

Step 7.

Step 8.

Step 9.

Step 10.

Each

Dredging

Untreated Sediment Storage

Untreated Sediment Handling

Coarse Solids Separation, Water, and HeatAddition

Extraction

Extract Collection

Treated Sediment Dcwatcring

Transportation of Treated Sediments

Offsite Disposal of Extracted Organics

Disposal of Treated Sediments.

of these steps is shown in the flow diagram,Figure 3- 1.

Process Operability

Foaming in the treated sediments and extract producttanks was evident throughout the SITE tests. This issuspected to be caused by propane entrainment in thetreated sediments propane mixture, and has two adverseeffects. First, extracted PCBs may be present in the foam.Second, foaming increases the volume of material thatmust bc handled in the product stream, thereby increasingthe probability of PCB migration and decreasing the feedthroughput. Foaming can bc mitigated by using oversizedtank volumes, which have lower surface-to-volumeratios;thus, nominal throughputs can bc maintained by use oflarge treated sediment collection tanks. CF Systems hasaddressed these issues in their scaled-up design and in thelatest unit to be built. The commercial designs also containan additional pressure relief step to more gradually de-crease the pressure and thereby decrease foaming.

Solids and oil retention in process hardware alsoaffected interpretation of SITE test data. The pilot-unitwas operated in a recycle mode to simulate multiple stages,which caused cross-contamination of the recycled treatedsediments. In addition, very small volumes were runthrough the unit during each day of testing. CF Systemsfull-scale units do not incorporate recycling, operate in aonce-through mode, and arc cxpcctcd to be on-line 20hours per day. Therefore, solids and oil retention is notcxpcctcd to be a significant problem, although some oilwill coat internal hardware surfaces and should bc re-

moved with an organic solvent if the character of the feedchanges substantially, to prevent cross contamination.Solids were observed in extracted oils; however, thisminor problem can be corrected by more frequent changesof filter elements or by selection of different filters.

3.5 Health and Safety IssuesThe SITE tests indicated that no acute threats to

operator health and safety arc associated with operation ofthe unit. Combustible gas meters indicated that the unit didnot leak significant amounts of propane. Therefore, opera-tion of the unit does not present an explosion threat muchdifferent from that associated with domestic propane us-age. Background air sampling and personnel monitoringresults indicate that organic vapors and PCB levels werepresent at levels below the detection limit for the analyticalmethods. The unit did not cause a sudden release ofpropane/butane or liquids. Only minor leaks occurred andstaging area soils were not affected. Gases vented from thesystem at the conclusion of the tests were passed througha carbon canister. Analysis results showed that the gasescontained minor amounts of PCB. The greatest threatpresented by handling of the New Bedford Harbor sedi-merits was dcrmal exposure. OSHA Level B protection isrecommended for personnel who handle treated and un-treated New Bedford Harbor sediment. Level C protectionis recommended for extraction process operators.

All electrical equipment is explosion proof and allpotential sources of ignition arc restricted for a 20-footperimeter around the unit. Spark-proof tools are also used.The solvent recovery hardware, which involves majorphase changes for propane, is very similar to commercialrefinery dcpropanizcrs, used safely throughout the world.

3.6 Testing ProceduresA portable GC and a chemist should be available

onsite to allow a rapid response to changes in feed compo-sition or operational control. The Spittlcr Method was usedat New Bedford as a more timely alternative to EPAmethods. However, even with this method, 24 hours wererequired for sample shipment and subsequent analysis.

Reviewers suggested the use of EPA Method 680,since the CF Systems technology could have selectivelyextracted higher molecular weight PCB congcncrs asopposed to lower weight PCB congcncrs. Method 680would reveal any selective extraction, since Method 680is used to analyze individual PCB congencrs. Method8080, a less expensive analysis method, would not revealselective extraction since it is used to analyze mixtures ofPCBs called Aroclors, instead of individual congcners.EPA Method 8080 was chosen over Method 680 sinceselective extraction was minor and since it analyzes for theclasses of congeners that compose the majority of PCB

18

Figure 3- 1. New Bedford Harbor Application Flow Diagram.

19

contaminants (Aroclors 1242 and 1254) in the harbor sediment PCB concentration of 8.700 ppm while Methodsediments. 8080 showed 2,575 ppm. Dataquality objectives were met

Methods 680 and 8080 produced similar relativefor each measurement. Therefore, regulatory or engineer-

results, but very different absolute results. Use of Methoding interpretation of future PCB analyses should include

680 in Test 4 showed a PCB extraction efficiency of 96consideration of the analysis methods used. Interpretation

percent and Method 8080 showed a similar efficiency, 87of results from any PCB treatability study should include

percent. However, Method 680 showed an untreateda discussion of the precision of the analysis method as wellas the accuracy

20

Section 4Economic Analysis

4.1 IntroductionThe objective of the economic analysis was to esti-

mate costs for a commercial-size siteremediation using theCF Systems technology. This evaluation illustrates howvariations in process conditions, such as volume to betreated, treatment time, water dilution of the raw feed, andreduction in outlet PCB concentration can impact systemdesign and pre- and post-treatment costs. Five treatmentcases were evaluated for PCB removal from New BedfordHarbor sediments to illustrate the cost methodology.

CF Systems developed costs for a base case and a hotspot case, then extrapolated the costs to three other cases.The base case refers to the treatment of 880,000 tons(695,000 cubic yards) of sediments containing 580 ppm ofPCB. The hot spot case refers to the treatment of 63,000tons (50,000 cubic yards) of sediments containing 10,000ppm of PCB. The three additional cases were developedthat represent variations of both the base and hot spot cases.These variations include changes of the on-stream factor,elimination of the need for adding water to reduce solidscontent, and higher PCB removal goals.

Standard process design sizing and costing algo-rithms were used by CF Systems. This consisted of: usingoff-the-shelf equipment of standardized size; obtainingtotal treatment capacity by adding units in parallel; andobtaining increased reduction of PCB outlet concentrationby adding units in series. CF Systems assigned an accuracyof plus or minus 20 percent to its cost estimates. This is areasonable estimate given the fact that off-the-shelf equipment is incorporated into CF Systems’ designs. Thisaccuracy goal falls within the order-of-magnitude esti-mates of plus 50 to minus 30 percent defined by theAmerican Association of Cost Engineers. Results of theanalysis and apparent trends are as follows:

l The estimated base case cost, including pre-andpost- treatment, is $148/ton of raw solids feed,with an accuracy range of $ 104/ton to $222/ton.Sediment excavation and pre- and post-treat-ment costs are 4 1 percent of the total cost. Thispost-treatment estimate does not include the fi-nal destruction of the concentrated extract.

l The above costs are based on a system designusing two PCU-1000 units, each with nominal

capacities of 250 tons/day. This design uses twoextraction units in parallel with one solvent re-covery section in series. One extraction unitconsists of two mixer/settler units. A totaltreatment time of 8.3 years is projected.The hot spot cost, including pre- and post- treat-ment, is $447/ton of raw solids feed, with anaccuracy range of $313/ton to $671/ ton, withsediment excavation and pre- and post-treatmentcosts being 32 percent of the total.The design for the hot spot case is based on thePCU-500, with a nominal capacity of 100 tons/day. This design utilizes two modules in series,with each module consisting of an extraction anda solvent recovery unit in series. A totaltreatment time of 1 year is projected.Key to all designs is the assumption of 85 percenton-stream factor. This was not demonstrated byoperating the PCU-20 unit at New Bedford Har-bor because of significant materials handlingproblems associated with recycle of treatedsolids. This recycle was required to evaluatePCB extraction using more than two extractionstages. Since recycle is not a unit operation fora commercial-size unit, CF Systems claims thatmaterial handling problems would be minimizedwith a commercial unit. CF Systems mustdemonstrate an 85 percent on-stream factor oncommercial unit.To attain a total treatment cost less than $lOO/ton, the solids feed content to extraction unitmust be greater than 26 percent to minimize pre-and post-treatment costs.

4.2 Basis for Process Design, Sizing, andCosting

In general, soil remediation projects encompass exca-vation, treatment, containment, and/or removal of con-taminated soils and sludges. Depending upon the types ofcontamination and the level of cleanup required, furtherprocessing of sediments treated by CF Systems’ extractionsystem may be necessary. This may include fixation forheavy metals and incineration of the extracted organics;

21

however, these costs are not addressed in this study. Atypical remediation project may consist of any combina-tion the following steps, for which equipment sizing andcosting is required to meet a specific treatment plan fortotal tonnage, treatment time, and reduction in contami-nant concentration:

1 The excavated material may have to be slurriedwith water to create a pumpable mixture.

2 The slurry is passed through a shaker screen toremove material larger than l/8-inch diameter.Oversized material may be crushed and recycledto the screens or separately washed.

3 The pH of the sieved slurry is monitored and, ifrequired, lime is added to the mixture to maintaina pH between 6 and 8.

4 The slurry may require thickening prior to theslurry being pumped to the CF Systems Extrac-tion Unit.

5 The slurry is processed in modular extractionunits to reduce the PCB content of the solids.

6 Two product streams exit the extraction unit: asolids/water stream and a liquid organic stream.The organic stream will generally be returned tothe client for reuse or disposal.

7 The solids/water stream is dewatered throughthe use of a gravity thickener, filter press, orcentrifuge. The water from the dewatering stepmay be reused to slurry dry feed solids. Excessdewatering effluent could be discharged to aPOTW or treated and discharged onsite.

CF Systems has developed a proprietary model forestimating siteremediation costs. Outputs of the model areonly intended for use in planning, scoping, and the invitingof firm bids. The Agency based this economic analysis onestimates prepared by the developer. No attempt was madeto mirror the developer’s work since this would involve asubstantial effort to design and cost a facsimile of CFSystems’ technology. Some features of the technology areunique to CF Systems’ design approach. These featuresinclude unit modularity, process component integration,safety instrumentation, relief system backup, and auto-matic shutdown.

A cost analysis was prepared by breaking the costsinto 12 groupings. These will be described in detail as theyapply to the CFS ystems technology. The categories, someof which do not have costs associated with them for thistechnology, are as follows:

l Site preparation costsl Permitting and regulatory costsl Equipment costs

Startup and fixed costsLabor costsSupply costsSupplies and consumables costsEffluent treatment and disposal costsResiduals and waste shipping, handling, andtransport costsAnalytical costsFacility modification, repair, and replacementcostsSite demobilization costs.

The 12 cost factors, along with the assumptionsutilized by CF Systems in their proprietary cost model, aredescribed below with respect to the soils treatment tech-nology.

SITE Preparation CostsApproximately 20 weeks are required to mobilize and

demobilize the extraction unit and pre- and post-treatmentequipment. The cost of ancillary service, such as construc-tion of concrete pads and rental of construction equipment,increases the site preparation costs by about 50percent. Noland costs are assumed for the New Bedford site.

Permitting and Regulatory CostsSince New Bedford Harbor is a Superfund site, it is

assumed that no permits will be required, neither Federalnor State. The need for developing analytical protocols ormonitoring records is assumed not to exist based on SITEprogram tests.

Equipment CostsCapital costs include equipment, maintenance and

technical service, engineering, procurement, fabrication,permitting, startup and operating assistance, and facilitymodification, repair, and replacement. Provisions for pre-and post-treatment of New Bedford sediment would in-volve solids handling and feed treatment equipment. Eachcost element is described below.

The solids handling equipment is provided to moveNew Bedford Harbor sediments from the stockpile to theCF Systems treatment site. Contaminated dry soils will beexcavated through the use of equipment such as frontendloaders, backhoes, or bulldozers. These soils will then befed into a preliminary screening.device to remove anymaterials larger than four-inches in diameter. Solids cap-tured in the screens will be collected, washed, and disposedof in an appropriate manner. Screened material will betransported on a conveyer belt to a pug mill where sizereduction is effected. The pug mill will combine the dry

22

solids with water to produce a solids/water exuudate. This Labor Costspaste will then travel via a second conveyer belt to a tankor pump where additional water will be added to produceslurried solids. Solids handling equipment costs are basedon 10 hours of daily operation for the duration of theremediation.

Feed pretreatment equipment is provided to screenand slurry the feed prior to the solvent extraction system.Slurried solids from either the pug mill or the dredge willpass through a multilayered shaker screen similar to thoseused in the oil drilling industry. The objective will be toscreen out solids larger than 3/16 inch in diameter. Solidscaptured by the screen will be collected, washed, andrecycled to the pug mill or crusher/grinder for size reduc-tion. Sludge passing through the screen will be collectedin a storage tank equipped with mixers. If required, limewill be added at this point to maintain a pH between 6 and8. The slurry will then be pumped from this tank either tothe extraction unit or to a thickener. If pumped to athickener, the slurry will be thickened to approximately 50-percent solids. This is accomplished through the use ofeither a moving screen or a decantation system, dependingon the water solubility of the waste. Water extracted by thethickener will be returned to the dredge area or to anotherapproved discharge point. The thickened solids slurry willbe pumped to another holding tank and then fed to theExtraction Unit.

The product handling equipment is provided to re-ceive the product streams from the extraction system and

The extraction unit would operate 24 hours a day, 7days a week. Fulltime operating staff would include 2operators and a shift supervisor. A site engineer and a sitemanager would be onsite 8 hours per day. Pre- and post-treatment would require 2 operators 24 hours a day, 7 daysa week. Safety equipment forall site personnel isestimatedto cost $40 a day per man, which includes disposal ofcontaminated gear.

Supplies and Consumable CostsNo supply costs are incurred.

Utilities CostActual equipment to generate and deliver utilities is

accounted for in the Startup and Fixed Cost Group. Utili-ties include electrical power and propane. Unit costs usedinthecostestimatesforelectricity were 6 cents per kilowatthour and 20 cents per pound of propane.

Effluent Treatment and Disposal CostsThe only continuous wastewater effluent associated

with this technology is once-through, noncontact coolingwater. If no closed loop system is available, water from thepost-treatment solids dewatering step would be used toslurry dry feed solids. Excess dewatering effluent wouldbereturned to the dredge area or intermittentIy dischargedto the harbor. The cost for monitoring these discharges isincluded in the Analytical Cost Group.

to deliver these product(s) to the Client for disposal. Thede-oiled solids and water produced from the extraction

Residual and Waste Shipping, Handling, and

process will be dewatered. This stream will be run throughTreatment Costs

a belt filter press, where a combination of pressure andconditioning flocculents, if required, will remove excesswater, leaving a cake with approximately 40- to 45 percentsolids. Water separated from the slurry will be returned tothe dredge area or to the water treatment system. De-oiledsolids in the form of a cake will move viaconveycr from thebelt filter press to a small blending mill.

Startup and Fixed CostsVarious facilities would be required to support the

operation and maintenance of the CF Systems technologyor any other onsite remediation technology. Those facili-ties would include office, laboratories, laboratory analy-ses, security, sanitary facilities, power generation, and acooling water supply. Most of these facility costs are lixcdfor a given site. However, some costs, such as powergeneration and cooling water supply, vary in proportion tothe capacity of the extraction unit.

No costs are estimated here for residuals shipping.The costs associated with treated solids dewatering andstorage and extract storage are estimated under the SitePreparation, Equipment, Labor, and Supplies Cost Catego-ries. Solids would be returned to the harbor or would betreated by fixation for metals. Extracted oils would betransported and incinerated at minimal cost since theextract could serve as a fuel supplement.

Analytical CostsIn the absence of a site sampling and analysis plan,

analytical costs are estimated at $500 per day and areincluded in the Startup and Fixed Cost Group.

Facility Modification, Repair, andReplacement Costs

These costs are borne by the developer since theequipment is marketed though lease agreements. There-fore, the developer has included these costs in the Equip-ment Cost Group.

23

SITE Demobilization CostsDemobilization costs are included in the Site Prepa-

ration Cost Group.

4.3 Developer’s Estimate for a New BedfordHarbor CleanupCF Systems prepared cost estimates using their pro-

prietary model for two cases: a large mass (695,000 cubicyards of sediment) of low PCB concentration (580 ppm)referred to as the “base case;” and a small mass (50,000cubic yards) of high PCB concentration (10,000 ppm)referred to as “hot spot.” Each is described below:

Base Case:The quantity of material to be treated, forthe base case, is 695,OOO cubic yards of PCB-contaminatedsoil. This quantity of material represents removal andtreatment of all the contaminated soil in the New BedfordHarbor estuary. The level of PCBs in this material isassumed to average 580 ppm on a dry solids weight basis.The PCBs in this material will be reduced to a 50-ppm levelvia solvent extraction. The time schedule for processingthis material is about eight years.

For this case, which involves a large tonnage removalfor multiple years on site, CFSystems recommends the use

of two PCU-1000s but only one solvent recovery section.This system will process about 500 tons/day in the follow-ing configuration:

HotSpot Case: Thequantityofmaterialtobecleaned,for the hot spot case, is 50,000 cubic yards of PCB-contaminated soil. This quantity of material representsremoval and treatment of the high concentration spots inNew Bedford Harbor. The level of PCBs in this materialis assumed to be 10,000 ppm on a dry solids weight basis.The PCBs in this material will be reduced to 10 ppm on adry solids weight basis via solvent extraction technology.This represents a 99.9-percent removal of PCBs. The timeschedule for processing this quantity of material is approximately one year.

For this case, CF Systems recommends the use of fourPCU-500s, which would complete the remediation inabout 1.2 years. These are 100 ton/day units, each havingits own extraction and solvent recovery sections. Theconfiguration of these units is shown below.

The selection of this size unit and the paired configu-ration is made to reduce onsite time and the units can bedeployed to other customers at the end of the job.. Two unitsin series are required to achieve an extraction efficiency of

PCU-1000Extraction

i

Pretreated 1--__

Waste I’

Sectionmm

I i

I;_______,,

‘------1

Solvent IRecovery kCrrrGnn

IIL PCU-1000 -1

ExtractionSection

ToProductHandling

i

24

r----- r-----

r-----) IPC”_500 1 If I r I----+ ,PCU-500 r----l

I I IPretreated+ -----4 - - - - - - To- - - - - I

WasteI !-

Product____

I-)Hapdling

Ir----- r-----

-----+ ,PCUdOO r----+ jPCU-500 1I II

Ji____-! i____~

99.9 percent. The parallel configuration is required tohandle the total volumetric throughput.

Process conditions and costs developed by CF Sys-tems are summarized for each case in Table 4-l. The basecase involved removing 9 1 percent of the PCB from a largevolume of sediment. The total average cost over the 8-yearduration of the project is $148 per ton treated. Pre- andpost-treatment costs represent about 4 1 percent of the totalcost. The hot spot case involves removing 99.9 of the PCBfrom a somewhat smaller volume of sediment. The totalaverage cost for treating hot spot sediments is $497 per tonover a project life of approximately one year. The pre- andpost-treatment costs account for 32 percent of the totalcost, Cost differences between base and hot spot cases aredue to the significantly different PCB removals required,as well as the different project lives.

Variations of the base and hot spot cases were evalu-ated to determine the cost impacts of different removalefficiencies, pretreatment requirements, and on-streamfactors. These various cases are listed below and arecompared to the base and hot spot cases:

Case 1A The base case: The base case in-volves the extraction of 91 percent PCBs con-tained in 695,000 cubic yards of harbor sedi-ments. An 8-year project life, and an 85-percenton-stream factor were assumed. The base caseincludes pre-treatment for the reduction of thesolids content.

Case 1B The base with a 70-percent on-streamfactor: This case is similar to the base caseexcept that an on-stream factor of 70 percent isassumed instead of 85 percent. A less optimis-tic on-stream factor would result if material-handling problems or equipment breakdownsocurred. A loweron-stream factor would require

equipment with higher capacities in order to keepthe project within an 8-year project life.

Case 1C The base case without solids contentreduction: This case is similar to the base caseexcept that no solids content reduction would berequired. Harbor sediments contain approxi-mately 40 percent solids; however, the SITEprogram tests showed that solids concent reduc-tion was necessary to improve pumpability.This involved adding water to the sediment toreduce the solids content to 17 percent. Theconsequences of water addition includeincreasedthroughput and increased equipment sixes. Withmore experience at the New Bedford site, CFSystems may be able to modify their equipmentand operating procedures to accommodate sedi-ments with 40 percent solids. Thus the need forwater addition would be eliminated, throughputwould be decreased, and equipment sixes wouldalso be decreased.

Case 1D The base case with increased extrac-tion efficiency: This case is similar to the basecase except that an extraction efficiency of 98percent, instead of 91 percent, is assumed. Thischange would result in a PCB outlet concentra-tion of 50 ppm instead of 100 ppm. Increasedextraction efficiency requires an increasednumber of extraction units that would be alignedin a series flow configuration.

Case 2 The hot spot case: The hot spot case in-volves treating 50,000 cubic yards of sedimentscontaining 10,000 ppm of PCB. An extractionefficiency of 99.9 percent, an on-stream factor of85 percent, and a 1-year project life are assumed.The hot spot case includes pretreatment for thereduction of the solids content.

25

Table 4-1. Base Case and Hot Spot Case Summary

CapacityRaw sludge (40% solids): cubic yards

tons

Processing Time: years

Operating Days

Raw sludge feed rate (at 40% solids)tons/operating day

Extractor Feed: % Solidstotal tons processednominal system size (tons/day)feed rate (tons/operating day)

Inlet PCB Concentration: ppm

Outlet PCB Concentration: ppm

PCB Reduction: percent

Configuration*

Processing Fee (1989 $)

Facilities

Extraction

Pre-/Post-Treatment

Contingency

Project Management

TOTAL

Total Life Cycle Unit Cost ($/ton):

Extraction only

Total

NOTES:

Base Case695,000880,000

8.35

2,591

339.5 171.5

26.7 26.71,319,414 94,922

500 250509.2 257

580 10,000

50 10

91 99.9

(1) (2)

$ 5,170,676 $ 762,496

$62,109,781 $15,857,695

$46,172,028 $ 7,993,608

$ 11,345,248 $2,461,380

$ 5,672,624 $1,230,694

$130,470,358 $28,305,869

$71 $251

$148 $447

Case50,00063,000

1.19

369

*Configuration: 1 - Two extraction sections connected in parallel feeding one solvent recovery section connected inseries.

2 - An extraction and solvent recovery section in series connected parallel with a second identicalextraction and solvent recovery section.

26

Costs for all of the cases were developed by CFSystems and are shown in Table 4-2. Process differencesamong the cases are also shown, as are costs for each costcategory. The differences among the cases provide thefollowing conclusions:

l A decrease in the on-stream factor from 85 to 70percent increases all costs by approximately 20percent. This is the result of increased equip-ment capacities and sizes required.

l Elimination of the pretreatment step to decreasethe solids content can result in a 30-percent costsavings. This savings occurs as a result of re-duced volumetric throughputs, reduced equip-ment sizes, and elimination of some pre- andpost-treatment steps.

l Changing the base case PCB removal goal from91 to 98 percent increases total costs by approxi-mately one-fifth. Although not shown in Table4-2, an additional case was evaluated to ob-serve the effect of reducing the PCB removalefficiency from 99.9 to 99 percent for the hotspot case. This resulted in a cost decrease ofapproximately one-quarter. Therefore, increas-ing or decreasing the removal efficiency by anorder of magnitude results in correspondingincrease of decrease of approximately 25 per-cent.

l Startup and fixed and analytical costs account for4 to 6 percent of remediation costs.

l Costs specific to the extraction unit account for53 to 68 percent of remediation costs.

l Sediment excavation and pre- and post-treatmentcosts account for 28 to4 1 percent of remediationcosts.

l Eliminating the need for decreased solids con-tent in the feed affects costs more than any othervariable. However, the greatest uncertainty lieswith the assumptions for the on-stream factorsince EPA has not evaluated this variable andCF Systems has no long-term operational dataavailable.

4.4 Evaluation of the Developer’s EstimateCF Systems has designed and built a 50-ton/day single

train system, which was shipped to a customer in the firsthalf of 1989 and was scheduled for startup in 1989. Theyhave also designed larger systems of lOO- and 200-tons/day throughput, but have not built these to date. Thesystem designed for the base case is called a PCU-2000and is configured as two 200 ton/day extraction sectionsconnected in parallel and one propane solvent recoverysection connected in series. The complete extraction

system provides a total capacity of about 500 tons/day,which, in combination with an 85-percent on-stream fac-tor, results in an 8-year treatment time for 695,000 cubicyards of sediment. The 92-percent reduction in solids PCBconcentration and 26-percent solids feed to the extractionunit are based on data obtained from testing the PCU-20 atNew Bedford Harbor.

The total life-cycle cost for the extraction unit was notdeveloped from an explicit capital cost investment (equip-ment list) or specific operating and maintenance costassessments. The developer’s proprietary estimates wereused in combinations with cost-capacity curves and ratiosbased on literature values and general experience. Thegreatest uncertainty associated with this estimate is relatedto the assumption of an 85-percent on-stream factor. Thereasons for this are:

Sizing and costing equipment to handle fivetimes the capacity of a first commercial unit isnot expected to involve major uncertaintiesbecause CF Systems utilizes industrial standard-ized off-the-shelf equipment.An on-stream factor could not be measured dur-ing the demonstration test at New Bedford withthe PCU-20 due to materials handling problemsassociated with recycling processed feed. Recy-cling is not a commercial design operation.Commercial operating data are not currentlyavailable for the PCU-200, which has beeninstalled and is in a startup phase at a refinery inTexas.If a commercial on-stream factor lower than 85-percent results, then a larger system design fortons/day would be required for the base case tomaintain the 8-year treatment time.

As a means of accounting for the uncertainty in the on-stream factor it is recommended that the cost range of plusor minus 20 percent for a budget estimate be downgradedto an order-of-magnitude estimate of plus 50 percent andminus 30 percent as defined by the American Associationof Cost Enginee rs. T his level of estimate is associated withno preliminary design work using cost-capacity curvesand ratios. This results in an accuracy range of $104/ton to$222/ton for the base case, and $317/ton to $67l/ton for thehot spot.

The developer’s extraction unit design and capitalcosts cannot be verified without a significant effort. Anyattempt to duplicate the proprietary design must includeprovisions for the unit’s modularity, the integration ofprocess components, safety-related instrumentation, pres-sure relief system backups, and automatic shutdown.However, some elements of the remedial design and esti-

27

Table 4-2. Estimated Cost

1ABase Case

Case On-StreamDescription(1) Factor Reduction

Total Waste Volume (Tons) 880,000 880,000PCB Reduction (Percent) 91 91Solids Content (Percent) 27 27On-Stream Factor (Percent) 85 70Remediation Duration (Weeks) 434 527

Site PreparationExtraction UnitPre/Post TreatmentExcavation

43.94Permitting and RegulatoryEquipment

Extraction UnitPre/Post Treatment

48.91Startup and Fixed CostsLabor

Extraction UnitPre/Post Treatment

SUPPlYSupplies and Consumables

Extraction Unit UtilitiesPre/Post Treatment Utilities

Effluent TreatmentResidual TransportAnalyticalFacility ModificationsSite DemobilizationTOTALS, $/ton

3.02 2.96 3.02 5.86 47.531.95 1.95 1.95 1.58 23.5721.44 26.03 13.97 17.14

48.39 58.52 31.53 77.8123.86 28.98 15.50 19.08

6.76 8.21 4.39 5.40 13.73

10.7210.80

17.062.29

______

1.98_-____

148.27

1B 1CBase Case Base Case

With Reduced Without SolidsContent

1D 2Base Case Hot spot

With IncreasedPCB Removal

Fff icierv;y

880,000914085

280

Estimated Cost, $/ton

880,000 63,00098 99.927 2785 85

347 64

173.57

13.02 6.97 10.86 33.6813.11 7.01 9.01 24.09

- - ___ -__ -__

19.51 11.08 23.91 29.202.78 1.48 1.83 4.68

___ ___ ___ ______ ___ _-- ___

2.41 1.29 1.59 4.07-__ ___ ___ -__-__ _-- -_- ---

177.48 98.19 174.09 446.97

Notes: 1) A narrative description of the cases appears in the text.2) These estimates are only intended for use in plannning, scoping, and the inviting of

firm bids. The American Association of Cost Engineers has established an accuracy goalof plus 50 to minus 30 percent for preliminary estimates such as these.

3) The costs shown are based on a proprietary model developed by CF Systems, Inc. Costmodel outputs are presented in Appendix B for the Base Case and the Hotspot Case.

28

matedcosts, which are not directly related to the extractionunit design, can be checked against available constructioncost data. Excavation, pre- and post-treatment equipment,and labor costs are the most significant cost elements asidefrom the extraction unit. Each of these elements is com-pared below to costs reported in the literature:

l Excavation--The base case excavation cost is$21.44/tan, which compares well with a $19.60/ton cost reported for bulk excavation in a cof-fer dam with a clamshell (Means, 1986).

l Pre- and Post-treatment--The base case cost is$23.86/tori,, and is composed primarily of unitcosts for leased equipment services. The unitcosts compare with costs reported in the litera-ture (Means, 1986).

l Labor--The base case labor cost is $21.52/ton or$43,635/week for 952 labor hours/week. Thesecosts are equivalent to an average labor rate ofS46/hour. This hourly rate is not unreasonablesince it is a composite rate that includes engincer-ing and management, costs for safety gear, andemployee benefits and overhead.

4.5 Extrapolation of CF Systems’ SludgeTreatment Costs to Other Sites

A generic cost model was developed to provide amethod for end users to estimate the remediation costs at aspecific site for the CF Systems sludge treatment technol-ogy. A total system cost consists of an extraction systemcost(E) and a pre- and post-treatment cost(P). A procedurehas been developed to estimate E as a function of: totalmass of sediments to be treated; total treatment time;percent reduction in PCB solids content; and level ofdilution of raw feed by water prior to extraction. A genericmethod of estimating P is not provided because this cost ishighly site-specific.

Development of the extraction system cost involvesthree steps:

l Defining the following elements: the basic PCUprocessing unit to be used (PCU-50, P C U -200, PCU-500, PCU-1000); the number of unitsin parallel (NP); and the number of units inseries (NS).

l Estimating unit capital and operating costs forone processing unit and then multiplying theseunit costs by NP plus NS to obtain the total ex-traction cost.- Select the total mass of solids to be treated (T)

and total treatment time (t).l Calculating the total system throughput of raw

feed by dividing T by t.- Calculate the total extration feed rate by ad-

justing the raw feed rate to account for waterdilution to condition the solids to the requiredsolids content required by the extraction sys-tem.

- Select a PCU series module of given capacity.- The number of parallel units is obtained by

dividing the total extraction feed rate by thecapacity of the PCU module selected.

- Select the fractional reduction in inlet PCBconcentration that is required.

- Some of the significant variables that affectextractability performance are: size and na-ture of solids; source and nature of organiccontamination; relativeconcentrations of vola-tiles and semivolatiles; age of feedstock; andinitial concentration. For purposes of scopingcosts, the reduction in concentration that canbe projected per module is a function of theorganic content of the feed: inlet concentra-tion in excess of l0percent,99.5-percent re-duction; for inlet concentration of 1 percent,95percent to 99percent reduction; and forinlet concentration less than 500 ppm, 95-percent reduction. If greater percentage re-moval of organics is required at correspond-ing inlet concentrations, then additionalmodules can be added in series or extrastages can be added per module.

4.6 Conclusions and RecommendationThe cost estimates developed by CF Systems for the

base case (estuary) and hot spot case involve two keyassumptions: that capital and operating costs can be scaledup to a commercial capacity based on pilot-scale testing ofthe PCU-20; and that an 85percent on-stream factor ap-plies to a commercial unit. Assumptions regarding scale-up of equipment costs are considered to be less criticalbecause CF Systems designs are based on purchase of off-the-shelf equipment, and field tests at New Bedford dem-onstrated that outlet PCB concentrations of 50 ppm and 20ppm were obtained using mixer/settler equipment. How-ever, the number of modules required to meet a totalthroughput capacity is dependent on the value of the on-stream factor. CF Systems must demonstrate an on-streamfactor of 85 percent for a commercial operation in order toreduce the uncertainty associated with projecting a cost of$148/to n for treating a large mass of New Bedford Harborsediments using CF Systems technology. This will alsoincrease the confidence in using the generic model toestimate costs for waste treatment at other sites. Based onthis discussion it is recommended that EPA verify thecredibility of the use of the 85percent on-stream factor.

Appendix AProcess Description

A.1 IntroductionCF Systems technology uses a liquefied gas. such as

propane or carbon dioxide, as a solvent to extract organicsfrom soils, sludges, and waste waters. The solvent is mixedwith the waste, then the solvent-organics mixture, (afterextraction) which is not soluble in the solids and water, isseparated from the solids and water. The pressure of theseparated solvent-organics mixture is then reduced tovaporize the solvent and separate it from the organics. Thesolvent is then recovered and compressed to a liquid forreuse. Separated organics are collected for disposal or usein fuel blends.

CF Systems currently offers two treatment systems.

l The soils and sludge system uses liquefied pro-pane to extract organics contained in a solidwaste using a series of mixer/settler units oper-ated at pressures below the critical point of pro-pane.

l The wastewater system uses liquefied carbondioxide to extract organics from a water streamusing a series of sieve extraction trays con-tained in vertical column which is operated at apressure at or near the critical point of carbondioxide.

Combinations of the above systems could be used toremove organics contained in both water and solids aftersegregating the water and solids phases.

A.2 Process Design Sludge Extraction System

Process DescriptionCF Systems Pit Cleanup Unit (PCU). shown in Figure

A-l, is a continuous processing unit that used a liquifiedpropane/butane mix as the extraction solvent. The solventmix was 70 percent propane and 30 percent butane. Foreach of the 3 demonstration tests, a batch of approximately50 gallons of sediments was fed to the unit at a nominal rateof 0.9 gpm. Feed viscosity was maintained below 1 ,OOOcP,by adding water in order to produce a pumpablc slurry.Particles greater than one-eighth inch were screened fromthe feed to prevent damage to valves. Sediments werepumped to theextractors, which were typically operated at240 psig and 70 degrees F. Liquified solvent was also

pumped to the extractors at a rate of 2.3 gpm (10 lb/min)and mixed with the sediments. Grganics, such as PCBs thatare soluble in the liquified solvent were extracted. Afterextraction, treated sediments were decanted and separatedfrom the liquified solvent and organics mixture. Themixture flowed from the extractor and passed to a separatorthrough a valve that partially reduced the pressure. Thepressure reduction caused the solvent to vaporize andseparate from the extracted organics. The solvent wasrecycled and compressed to a liquid for reuse in the system.

The PCU-20 was not designed for large-scale reme-dial actions. Therefore, treated sediments were recycled,or passed through the unit to simulate operation of acommercial-scale unit. CF Systems’commercial-scale de-signs do not include recycling. These designs feature 60gpm flowrates, several extraction stages, and longer proc-essing times.

Equipment SpecificationsThe major pieces of equipment and their function are

described in Table A-l. Process equipment that contactedthe solvent or feed materials were constructed of 316stainless steel. All process pumps were constructed ofstainless steel, and both compressors were made of carbonsteel. All of the process equipment was designed towithstand temperatures and pressures that exceed normaloperating conditions. To guard against sudden overpres-sure, each vessel had a relief valve that vented to a headersystem that discharged to the pollution control system.Table A-l outlines the major equipment items and thefunction of each piece of equipment in the process.

The utility and process materials requirements thatwere necessary to operate the PCU at New Bedford Harborwere:

l

.

.

.

.

31

Electricity--480 VAC 3 Phase, 100 ampsProcess Water--5 GPM, 60-80 degrees Finlet, 30-90 psiPotable Water--AvailablePropane--four, 100 gallon bullets, 95-97percent purityButane--As needed, for Propane/Butane (70/30) solvent mix

Table A-l. Process Equipment Description

Process Equipment

Feed Kettle

Designation

FK

Basket Strainer

Extractor 1

Decanter 1

S--1

E-l

D-l

Extractor 2

Decanter 2 D-2

Cartridge Filter F-2

Solvent RecoveryColumn

Column Reboiler

Treated Sediment(Raffinate) Product Tank

Extract Product Tank

Main Compressor

Low Pressure SolventCompressor

E-2

SRC

CR

RPT-1RPT-2

EPT

C-l

C-2

Function in System

Holds approximately 100 gallons ofstrained, slurried feed. Counter-rotatingagitators homogenize feed.

Prevents oversized (>1/8 inch) feedmaterial from entering the system.

Extracts organics from water-solids feedmixture with solvent from D-2.

Allows separation of solvent-organicmixture from water-solids layer. Sendswater-solids layer to Extractor 2 (E-2)and solvent-organics layer to the solventrecovery system.

Extracts organics from water-solidsmixture with fresh propane from thesolvent recovery process.

Allows separation of solvent-organicslayer from water-solids mixture.

Filters residual solid fines from solvent-organics stream leaving Decanter 1 (D-l).

Separates propane solvent from organicsvia pressure reduction and heat from theColumn Reboiler (CR). Solvent vapor flowsout the overhead while organics aredeposited in the CR.

Provides both holdup for the recoveredorganics and heat for the Solvent RecoveryColumn (SRC) via a tube bundle heatexchanger.

Receives treated sediments (raffinate)from Decanter 2 (D-2). Recovers residualpropane via flash pressure reduction andheat from water jacket. RPT-2 receivesRPT-1 overflow.

Receives extracted organics effluent fromthe Column Reboiler (CR). Recoversresidual propane via flash pressurereduction and heat from the water jacket.

Compresses both Low Pressure SolventCompressor (C-2) outlet solvent andSolvent Recovery Column (SRC) overheadsolvent. Outlet sent to Column Reboiler(CR) for heat exchange before returningto Extractor 2 (E-2).

Compresses scavenged propane from Extractand Raffinate Product Tanks (EPT, RPT-1,and RPT-2). Sends compressed solvent toMain Compressor (C-l ).

33

Table A-2. Range of Operating Conditions for Testing

Extractor Pressure (PSIG)

Extractor Temp. (degrees F)

Feed Temp. (degrees F)

Solvent Flow (lb/min)

Feed Flowrate (GPM)

Solvent/Feed Ratio

Feed Solids (percent by weight)

Solids Size (maximum)

pH (standard units)

Viscosity (cP)

Minimum

180

6060

8

0.2

10__

6

0.5

l Nitrogen (forpressure testing during shakedownperiod)--(2) 1A size cylinders.

Utility usage for a commercial-scale unit cannot beeasily compared with the PCU because pilot-scale equip-ment consumed much more energy per gallon of through-put

The operating conditions listed in Table A-2 are essen-tial to the efficient operation of CF Systems’ pilot-scaleunit. Failure to operate the unit within the specifiedoperating ranges can result in decreased extraction per-formance. The operating parameters were set during theshakedown portion of the demonstration. CF Systemsclaimed that minor fluctuations would not affect perform-ance.

The feed temperature is that of the material piped intothe feed kettle. The feed must be maintained above 60degrees F to avoid freezing, which could interfere with theextraction process. The feed must be maintained below120 degrees F to prevent vaporization of the solvent.

The extractor pressure, measured at the gauges onextractors 1 and 2, is controlled by the main compressorand at the extract discharge from the extraction segment ofthe unit.

The viscosity and solids content must be such that thefeed material is pumpable. Pretest sampling determinesthe viscosity of the potential feed. Any potential feed witha viscosity above the listed range is slurried with water toyield a pumpable mixture.

In order to prevent damage to the process equipment,the pilot-scale unit has a maximum limit for solids size.Basket strainers, located bctwcen the feed pump and the

Nominal Maximum

240 300

100-110 120

70 100

12 15

0.2-0.5 1.5

1.5 2

30 60__ l/8 inch

7 12

10 1,000

first extractor, prevent larger-than-allowable size solidsfrom entering the system. Oversized solids removed fromthe feed were hauled to an RCRA-approved facility.

The feed flow rate represents the rate at which mate-rial is pumped from the feed kettle into the extractionsystem. Operational flow rates above the listed maximumcan force segments of the system, such as decanters andcontrol valves, beyond their effective hydraulic capacity.The feed flow rate is manually controlled through the feedpump controller located beneath the feed kettle. Averagedetention time of throughput is about one hour.

Process Flow Diagram

The PCU process flow diagram is shown in Figure A-2. The extraction portion of this unit consisted of twostages of counter-current extraction with solid-liquid sepa-ration between the extractors. The feed was transferredfrom a feed preparation drum to the feed kettle with apump. In the feed kettle, slurry solids were kept suspendedwhile in the feed kettle by two counter-rotating agitators.During this process, feed was pumped from the feed kettlethrough a basket strainer, which removed any particlesgreater than l/8 inch in diameter. Then feed flowed to thefirst extractor, where feed was mixed with the liquidpropane/butane solvent. An agitator (not shown in thefigure) provided mixing action before the solvent-organicsmixture flowed to decanter 1. At decanter 1, the mixtureseparated into two immiscible layers. The solids and watersettled into the underflow to the second extractor. Thedecanter overflow, which contained extracted organics,propane/butane, and fine solids, flowed through a filterandthen to a solvent recovery column.

The pressure difference between the first decanter andthe second extractor moved the solid-liquid stream into the

34

z: i

Figure A-2. CF Systems Process Schematic.

35

second extractor for second-stage extraction. Fresh liq-uified solvent (propane/butane mixture) from the solventrecovery process then mixed with the solids/water streamand further extracted the organic components. An agitator(not shown in the figure), which was located above thesecond extractor, provided mixing action before the sol-vent-organics mixture flowed to decanter 2. At decanter 2,two immiscible layers were formed. The organics-solventlayer floated to the top while the solids sank into theunderlying water layer. The lower water-solids layerflowed from the bottom of the decanter to the treatedsediment product tanks, while the upper organics-solventlayer recycled to the first extractor for final stage extrac-tion.

The organic-solvent stream from the first stage extrac-tor passed through a filter cartridge that collected finesolids and went to the solvent recovery column. In thesolvent recovery column, the solvent vaporized and wasremoved from the column overhead, while the organics re-mained as a separate liquid. The mixture of organicscontaining dissolved propane gathered in the column re-boiler and subsequently passed to the extract product tank.Solvent from the column overhead flowed to the maincompressor. The compressed solvent passed through thecolumn reboiler heat exchanger to provide the heat neces-sary to boil off residual solvent remaining in the organicmixture. The condensed solvent left the reboiler and re-entered the extraction system via the second extractor.

The residual solvent that vaporized off the systemproducts in the extract or the treated sediment tanks flowedto the low-pressure solvent compressor. The outlet streamof the low-pressure solvent compressor fed to the maincompressor, where it was compressed along with vaporsfrom the column overhead.

During system shutdown or if overpressure within avessel opens a relief valve, material is vented to a reliefheader, which directs the material to a blowdown tankwhere solids and liquids are removed from the ventedstream. The gases from the blowdown tank pass througha 42-gallon activatedcarbon filter to removecontaminantsin the propane gas. The gas then passes through a flamearrestor and is vented to the atmosphere. This system wasused only once during the demonstration, at the conclusionof PCU decontamination.

A.3 Process Design Waste Water Extraction System

Process Description

The CF Systems wastewater extraction process is asolvent extraction technique which, instead of using atypical solvent such as methylenc chloride, toluene orhcxane, uses liqucficd carbon dioxide (COJ gas. Thissolvent has high solubilitics for most hazardous organic

compounds. In addition, CO2 is inexpensive, non-toxic,and can be easily separated from the extracted compounds.In contrast to the sludge unit the wastewater unit uses asieve tray extraction instead of mixer/settler extractionunits.

Figure A-3 provides a simplified flow diagram of theCF Systems extraction process using liquid CO2 as asolvent to extract organics from wastewater. As shown inthe figure, organic-bearing wastewater is contintiously fedinto the top of the extractor and flows down the columnthrough a series of sieve tray downspouts. Simultaneously,liquid CO2 is fed into the bottom of the extractor, and jetsupward through perforations in the sieve trays becauseliquid CO2 has a lower density than water. During thiscountercurrent contact between CO2 and wastewater, or-ganics are dissolved out of the water phase to form a COJorganics phase, or extract, which continuously exits fromthe top of the extractor. As the extract stream flows fromthe extractor to the separator vessel, it passes through apressure reducing valve that allows some of the CO2 to va-porize and exit from the top of the separator. The CO2

vapor leaving the top of the separator vessel is continu-ously fed to a compressor, recompressed, liquefied andthen reused as fresh solvent, resulting in a totally enclosedrecycle system. In the separator vessel, as CO2 changesphase from liquid to vapor, the liquid organics are releasedand flow to the bottom of the separator, where they arecollected and removed as a concentrated stream usuallycontaining less than five percent water. Both the concen-trated organic stream and the water effluent from thebottom of the extractor vessel are reduced in pressure priorto being pumped off-skid.

.

.

36

Equipment SpecificationCF Systems Organics Extraction Unit ModelLL2OCO-1 is designed such that the extractionprocess will not be interrupted by componentfailure. To accomplish this, each component hasdesign parameters appropriate to its function inthe process. Most components are designed foruse in environments with temperatures and pres-sures of 350’Fand 150 psig, respectively. TableA-3 lists all major components and their func-tions. Utility and process water requirementsare given in Table A-4.Process Flow DiagramThis section describes the functioning of themajor operating units shown in a process flowdiagram; Figure A-4.Extract lionIn the extraction process, the wastewater feed ispumped from a storage tank through a strainer,a heat exchanger, and then to a surge drum. The

Simplified Flow Diagram.

37

Table A-3. Major Components and FunctionsComponent # Name

T-l Extractor

T-2 Solvent RecoveryColumn

D-l Feed Drum

D-2

D-6

D-7

D-9

D-11

E-l

E-2

E-3 Solvent Subcooler

(continued)

Medium PressureExtract Flash Drum

D-3 Low Pressure ExtractFlash Drum

D-4 Medium PressureRaff inate Flash Drumwater.

D-5 Low PressureRaff inate Flash Drum

C-2 InterstageKnockout Drum

C-3 InterstageKnockout Drum

C-l SuctionKnockout Drum

CO, Storage Drum

Column Reboiler

After condenser

Function

Provides contact between the water-organics feed stream and the liquidCO2 solvent.

Separates most of the CO2 solventfrom the organics in the extractstream.

Intermediate surge for the wastewater feed between the low pressurepump (GP-102) and the high pressure feed pump (P-l).

Provides intermediate pressureseparation of CO2 solvent from extracted organics and cooling of CO,

vapor discharged from the secondstage of the Low Pressure Compressor (C-3).

Provides low pressure separation ofCO2 from the organics.

Provides initial separation of CO2

fromextracted water.

Provides final separation of the CO2

from extracted water.

Provides removal of any organicscondensed from the CO,vapor goingto the second stage of the MediumPressure Compressor (C-2).

Provides removal of organics condensed from CO2 vapor before entering the second stage of the LowPressure Compressor (C-3).

Provides removal of any liquid condensed from the CO2 vapor from the

Solvent Recovery Column (T-2) andthe C-l Recycle Cooler (E-S) beforethe vapor enters the Main Compres-sor (C-l).

Provides location for CO2 storage.

Heat exchanger used to transfer theheat of vaporization to the liquidCO2 in the Solvent Recovery Col-umn (T-2).

Heat exchanger used to condense theCO2 vapor/liquid mixture comingfrom the Column Reboiler (E-l).

Cools the liquid CO2 from theAftercondenser (E-2)

38

Table A-3. (Continued)Component #

E-4

E-5

E-6

E-7

E-8

E-10

C-l

P-l

P-3

P-4

P-5

Name

Feed Precooler

C-l Recycle Cooler

C-2 Intercooler

C-3 Intercooler

C-l Lube Oil Cooler

Reflux Cooler

E-12 C-2 Recycle Cooler

E-13 C-3 Recycle Cooler

E-14 D-2 Reboiler

Main Compressor

C-2 Medium PressureCompressorExtract Flash Drum (D-2).

C-3 Low Pressure

Feed Pump

Solvent ChargePump

Extract Pump

Raff inate Pump

C-l AuxiliaryLube Oil Pump

39

Function

Cools the incoming wastewater feedfrom storage.Cools the CO2 vapor recycled throughthe Main Compressor (C-l).

Cools the hot compressed CO2 va-porfrom the first stage of the MediumPressure Compressor (C-2) before itenters the second stage of C-2.

Cools the hot compressed CO2 va-por from the first stage of the LowPressure Compressor (C-3) before itenters the second stage of C-3.

Cools the lube oil for the MainCompressor (C-l).

Cools the liquid CO,from the SolventSubcooler (E-3) before it enters theSolvent Recovery Column (T-2) toaid in CO2 vapor and organics sepa-ration.

Cools the CO2 vapor recycled fromthe Medium Pressure Compressor(C-2) back into the Medium Pres-sure Extract Flash Drum (D-2).

Cools the CO2 vapor recycled fromthe Low Pressure Compressor(C-3)back to the Low Pressure ExtractFlash Drum (D-3).

Supplies heat to the liquid in thebottom of the Medium PressureExtract Flash Drum (D-2).

Compresses the CO2 vapor from theSolvent Recovery Column (T-2).

Compresses the CO,vapor collectedin the Medium Pressure

Compresses the CO2 vapor collectedin Compressor the Low PressureExtract Flash Drum (D-3).

High pressure pump taking wastewater from the Feed Drum (D-l) and theExtractor (T-l).

Pumps CO2 makeup into the SolventRecovery Column (T-2).

Takes suction on the Low PressureExtract Flash Drum (D-3) discharg-ing to storage.

Takes suction on the Low PressureRaffinate Flash Drum (D-5) discharg-ing extracted water to storage.

Provides initial lube oil pressure tostart Main Compressor (C-l).

Table A-4. Utility and Process Water RequirementsElectric Power Criteria

460V, 3 phase, 60 Hz AC electric power is distributed to the following loads:

Comoonent (item no.) MotorMain Compressor (C-l) 125Medium Pressure Compressor (C-2) 60Low Pressure Compressor (C-3) 25Feed Pump (P-l) 20Extract Pump (P-3) 5Raffinate Pump (P-4) 5C-l Auxiliary Lube Oil Pump (P-5) 1Feed Mixer (MX-1) 0.5

Total Connected

Requirement

Hot Water Criteria

241.5

Design Value

Supply TemperatureSupply PressureDesign Flow RateReturn TemperatureDesign Pressure Drop Across SkidsThermal Relief Valve Setpoint

Individual component hot water requirements are listed below:

180” FBy Client25 GPM150° F20 psi100 psig

Individual Comoonent

Feed Drum (D-l)Medium Pressure Extract Flash Drum (D-2)Low Pressure Extract Flash Drum (D-3)Total Hot Water

Refrigerated Water CriteriaRefrigerated water is supplied at the following conditions:

Flow Rate (GPM)

13.39.11.5

23.9

Design Value

Supply Temperature 55 “FSupply Pressure By ClientDesign Flow Rate 110GPMReturn Temperature 70 “FPressure Drop Across Skid 30 psiThermal Relief Valve Setpoint 100 psig

Individual component refrigerated water requirements are as follows:

Refrigerated Water RequirementsComoonent

Aftercondenser (E-2)Solvent Subcooler ((E-3)Feed Precooler (E-4)C-l Recycle Cooler (E-5)C-2 Inter and Recycle Coolers (E-6/E-l 2)C-3 Inter and Recycle Coolers (E-7/E-l 3)C-l Lube Oil Cooler (E-8)Reflux Cooler (E-10)Total Refrigeration Requirement

Design ValueFlow Rate (GPM)

303030564

_12_109

40

strainer removes any solid particles larger than60 mesh to prevent these solids from entering thehigh pressure feed pump and the extractor. Theresulting strained feed stream has no more thantwo percent suspended solids. The Feed Pre-cooler (E-4) cools the wastewater feed to a tem-perature below 70°F. The jacket on the feeddrum heats the wastewater to above 65 OF. TheFeed Drum (D-l) provides five minutes of re-serve feed for the system process.From the feed drum, wastewater is pumped bythe Feed Pump (P-l) to the Extractor (T-l) atabout 950 psig. Wastewater enters at the top ofthe extractor and flows downward countercur-rent to the CO2 solvent stream. The CO2 solvententers at the bottom of the extractor and flowsup through the column as the dispersed phase.The column internals consist of sieve trays anddowncomers. CO2 passes through the sievetray holes as it flows upward from stage to stage.The aqueous solution, coming from the top,flows across a sieve tray before passing througha downcomer to the stage below. The arrange-ment allows for optimum mixing and contactbetween the fluids to accomplish extraction ofthe organics into the CO2 solvent.The extract stream from the top of the extractorconsists of liquid CO2, organics extracted fromthe feed stream, and a small quantity of dissolvedwater. The organics concentration in the extractstream is over 98 weight percenton a COifree basis. The CO2-organics extractstream flows through a pressure-reducing valveand is partially flashed. By reducing thestream pressure from 935 psia to 750 psia. about15 percent of the CO2 vaporizes. During theflash evaporation process, the liquid losessensible heat to vaporize the CO2 and is cooledfrom 70 OF to 60 ’ F. At the lower temperature,the solubility of water in CO2 decreases and awater phase is formed.

Pressure Letdown and Carbon Dioxide Distilla-tionAn important feature of the CO2 distillationand stripping is that the bulk of the CO2 in theextract stream is separated from the productorganics at a pressure that is very near theextractor pressure. This minimizes thecompression work needed to recycle the CO2

back to the extractor.The CO2 separation is performed in theSolvent Recovery Column (T-2).Vaporization heat is supplied from two

sources. First, the hot compressed CO2

vapor discharged from the Main Compressor(C-l) gives up its sensible heat of cooling andlatent heat of condensation as it cools from thevapor phase and condenses into the liquid phase.A kettle type heat exchanger, Column Reboiler,(E-l) is provided perform the heat exchange.Second, superheated CO2 from the second stagedischarge of tbe Medium Pressure Compressor(C-2) is injected into T-2 for direct heat ex-change.The column reboiler kettle is equipped with aboot for collecting the water layer formed in thepressure letdown and CO2 distillation. The waterlayer, which will contain some organics, collectsin the boot and is recycled back to the feed drumfor organics recovery.

l Extract Stream Flash EvaporationThe overhead CO2 vapor from T-2 is fed to thesuction of compressor C-l. The still bottomsstream contains about fifty percent of the CO2

originally present in the extract stream, is fed intoa cascaded flash evaporation stage for furtherCO2 removal.This organics-rich bottoms stream is first flashedacross a control valve to about 125 psia. Thisstream flows into the Medium Pressure ExtractFlash Drum (D-2) where the vaporized CO2 isvented to compressor C-2 for recompression.The liquid is removed from D-2 on level controland flashed to a final pressure of 20 psia in D-3,the Low Pressure Extract Flash Drum, for nearlycomplete removal of CO2. The CO2 vapor fromD-3 goes to the first stage of the Low PressureCompressor (C-3). The organics extract streamis withdrawn from D-3 on level control and ispumped to storage by the Extract Pump (P-3).Some of the heat required to vaporize the CO2 indrum D-2 is supplied by the superheated CO2

coming from the second stage of C-3, which isinjected directly into D-2. D-2 is equipped witha heating coil, and D-3 with a heating jacket, toheat the organics and to help remove the CO2

CO2 vapor from the Raffinate Flash Drums (D-4and D-5) is also injected directly into the extractflash drums.

l Raffinate Stream Flash EvaporationThe vapors from the Low Pressure RaffinateFlash Drum (D-5) are combined with the vaporsfrom D-3 before recompression by C-3 and in-jection into D-2. Similarly, the vapors from theMedium Pressure Raffinate Flash Drum (D-4)

41

Feed Pump(P-1)

Raffinate Flash Drums

ClPMainCompress0

Extractor(T-1 ) yy 1 Solvent

RecoveryColumn

CT-3After

Condenser(E-2) Column Reboiler

4 E-1)

7I

YH-

,

MediumPressure

Compressor

LowPressure

Compressor

Figure A-4. CF Systems Organics Extraction Unit Simplified One-Line Diagram.

42

are combined with the vapors from D-2 beforerecompression by C-2 and injection into T-2.The pressure in the raffinate flash drums is con-trolled by backpressurecontrollers located in thevapor outlet lines on the two extract flash drums.Both D-4 and D-S are equipped with level con-trollers for maintaining proper liquid flow fromthe drums. From D-5, the raffinate stream ispumped to a storage tank by Raffinate Pump(P-4).

l Carbon Dioxide Recompression, Condensing andRecyclingThe last process involves recompressing, con-densing, and recycling the CO2. The CO2 vaporcoming from D-3 is compressed from 18 psia to128 psia by compressor, C-3. The CO,vapor dis-charged from C-3 is injected into drum D-2 fordirect heat exchange with the liquid in this drum.The CO2 vapor coming from D-2 is compressedfrom 124 psia to 753 psia by compressor, C-2.The CO2 vapor discharged from the second stageof C-2 is injected into the Solvent RecoveryColumn (T-2) for direct heat exchange to help

vaporize CO,and to cool the hot compressed CO2

stream. The overhead vapor from T-2 is fed tocompressor C-l for final recompression from745 psia to a final pressure of 980 psia. Both twostage compressors, C-2 and C-3. are equippedwith intercoolers and knockout (KO) d r u m s .The vapor flowing to the first stage of the com-pressors contains a small amount of organicvapor. When the hot stream from the first stage iscooled, the organics condense. This liquid has tobe removed in a knockout drum before the vaporgoes to the compressor second stage. Liquid or-ganics are removed from the knockout drums onlevel control and are drained to their respectiveextract flash drums.From the main compressor (C-l) discharge, theCO2 flows through three heat exchangers in se-ries. In the heat exchangers, the CO2 is cooled,condensed, and subcooled to 70 OF so that it canbe recycled to the extractor tower. The CO2 iscooled and partially condensed by supplying theheat of vaporization of CO2 in the kettle. Thesubcooled liquid CO2 from the last exchangerthen flows to the Extractor (T-l).

43

Appendix BDeveloper (Vendor) Comments

1. IntroductionCF Systems Corporation (CF Systems) is a technol-

ogy-based company in the hazardous-waste-treatment andresource-recovery business, offering services and equip-ment based on a proprietary extraction technology. CFSystems’ solvent-extraction units aredesigned for removalof organics from soils, sludges, and aqueous streams,concentrating the extracted organics for recovery or finaldisposal. The result is the minimization of waste volumes,reduction of treatment and disposal costs, and recovery ofmaterials such as oil products, solvents, and chemicals.

In August 1988, the U.S. EPA designated solventextraction as Best Demonstrated Available Technology(BDAT) for petroleum refinery wastes (K048X052).Performance data from CF Systems were incorporated inthe evaluation used to set these standards for RCRArefinery waste treatment.

CF Systems has demonstrated the effectiveness of itsextraction technology through the operation of its MobileDemonstration Unit (MDU) for nearly two years. To date,the MDU has operated at eleven locations, includingrefineries, chemical plants, and treatment, storage anddisposal (TSD) facilities in the United States and Canada.

In general terms, use of CF Systems’ extraction tech-nology provides important benefits for remediation andtreatment for land disposal:

By-product credits for the recovered organics;Significant volume reduction of the treated sol-ids;Effluent water acceptable for conventional was-tewater treatment;An environmentally acceptable extraction sol-vent with low residues.

2. Commercial ActivityCF Systems’ major commercial activity has consisted

of the following:

Texaco awarded CF Systems a 14 month reme-diation contract to clean-up 20,OOOcubic yardsof First-Third refinery wastes at its Port Arthur

.

.

.

45

Refinery in Texas. This is the first commercialapplication of any type of solvent extractiontechnology to treat hazardous waste in the petro-leum industry. The Texaco project includes feedpretreatment and material handling services, aswell as the solvent extraction system. CFS hasinstalled a full-scale PCU-200 solvent extrac-tion unit at the site and start-up of the system isscheduled for mid-June, 1989.

In November, 1988, Clean Harbors Inc. pur-chased a commercial-scale LL-20 system toprocess 20 gallons per minute (GPM) of organicwastewaters at their Baltimore facility. The unitwill be shipped for start-up in July, 1989.Clean Harbors is a rapidly-growing company inthe commercial waste treatment, storage, anddisposal (TSD) business, with multiple loca-tions nationally. The LL-20 unit will treat a widerange of organic wastewaters to produce dis-posable water and an organics fraction generallysuitable for fuel use.A custom 60 ton-per-day system was purchasedby ENSCO’s El Dorado, Arkansas incineratorfacility. The unit is designed to extract organicliquids from a broad range of hazardous-wastefeeds sent to the site for incineration. The treatedsolids produced by thesystem willbeprocessedby the incinerator at a much faster rate than un-treated solids due to their reduced fuel value andthe extracted liquids can be used as incineratorsecondary combustion fuel.The 20 barrel-per-day mobile unit (MDU) hasbeen in operation for test and demonstrationpurposes under client funding since September,1987. Operating experience includes six petro-leum refineries, U.S. and Canadian; a U.S. chemi-cal plant; a Canadian TSD site; two Super-fundsites, a PCB clean-up under this EPA SITEprogram sponsorship, and the other awoodtreating waste impoundment. In April,1988, a commercial clean-up job was performedat a major chemical company in New Jersey.

3. The TechnologyCritical-fluid solvents, the basis for the CF Systems’

technology, are condensed gases or supercritical fluids,such as carbon dioxide, freon, propane, ethylene, ammoniaand others, in the vicinity of their critical points. Above thecritical point, the transition from gas to liquid is continuousrather than abrupt. At or near such conditions, fluids havevery favorable solvent properties. They behave like liquidsin that they are capable of dissolving significant amountsof oil or other substances. They behave like gases in that therates of extraction are extraordinarily high compared toliquid solvents.

In the CF Systems process, a liquid feed such as anorganic-containing hazardous waste is admitted to an ex-tractor, along with the solvent. At or near the solventcritical point (usually ambient temperature and severalhundred psi), the organics in the waste dissolve into thesolvent. The two phases are separated, extracted organicsare removed with the solvent, while clean water and solidsare removed through an underflow. The extract then goesto a second vessel, where the temperature and pressure aredecreased, causing the organics to separate from the sol-vent. Clean solvent is recycled to the extractor, andconcentrated organics are recovered and removed.

Examples of organic pollutants that can be extractedeconomically using the CF Systems unit include a widerange of aromatic and aliphatic hydrocarbons, chlorinatedhydrocarbons, phenols, alcohols, ketones, ethers, andorganic acids. The CF Systems technology can be appliedto sludges and solids as well as liquid wastes.

4. CF Systems Equipment SystemsCF Systems has developed a series of standard modu-

lar equipment systems. For sludge and solids treatment, thecapacity range is about l0-500 tons per day; for liquids,about 5-30 gallons per minute (GPM). Treatment systemsare assembled as skid-mounted modules to facilitate shipping and field assembly. Production of standard modulesalso allows high quality, low-cost fabrication.

4.1 The PCU-Series

The PCU-series systems are designed to process high-solids sludge feeds and contaminated solids such as soils.They contain specially-designed extractors and separatorsto facilitate the treatment of oily solids typical of petroleumsludges and waste materials found in refinery impound-ments requiring remediation. Organics removal can be ashigh as 99.9% or better. At this time the PCU series designhas been economically optimized to meet the projectedrequirements for remediation of both relincry and Supcr-

fund applications. Where high levels of clean up arerequired theeconomics of the technology will favor opera-tion of the systems at higher temperature and pressures.

The systems included in this product series are:

PCU-50 - This system, designed to process amaximum of about 12 tons per day, is a standardproduct for refinery sludges regulated by EPA’sRCRA land-disposal ban, impoundment sludges,and oil- and PCB contaminated soils and silts.The system is skid-mounted and designed forinstallation into confined spaces and ready inte-gration into existing operations.PCU-200 - This system, designed to process amaximum of about 50 tons per day, is a larger-scale product for oily sludges and contaminatedsoils. The system is mounted on two trailers,and can be mobilized and demobilized in l0-15days.PCU-500 - The PCU-500 is a modified PCU-200design, with the same solvent-recovery subsys-tem, but increased extractor capacity to pro-vide for throughputs up to about 100 tons perday. Depending on location and cleanout re-quirement, mobilization-demobilization mayrequire 4-8 weeks.PCU-1000 -This system, with a 200 ton-per-daynominal capacity, is intended for large remedia-tion jobs and relatively long terms (one year ormore)atasinglelocation. It is skid-mountedandtransportable, but with multiple modules, requir-ing 2-3 months for mobilization and demobili-zation.

4.2 The LL-Series

The LL-series systems are designed for the extractionof dissolved or emulsified organics in water streams.Solids are usually not present at a significant level in thesestreams, or must be removed to the 2-3% level as apretreatment. Organics content of the feed can range ashigh as 30-50% andremovalefficienciescan exceed99.9%.The market for the LL-series includes a wide range oforganics wastewaters.

The systems are skid-mounted and transportable;however, the extractor is a column which is field-erected.In contrast to carbon steel in the PCU systems, stainlesssteel is required for this series because of the corrosionpotential of the feeds.

46

5. The Product and the Application5.1 Applications

The technology is applicable to any solid or liquidfeedstock which contains organics water. Depending onthe feedstock type and organics various solvent systemsare available to meet the product specifications.

For organics contaminated waste water the solvent ofchoice is carbon dioxide which enables most semi solubleorganics to be extracted from the water. Even highlysoluble organics such as alcohols may be extracted bycorrect design of the extraction system.

For sludges where petroleum hydrocarbons or chlo-rinated hydrocarbons are present together with solids pluswater, propane is the solvent of choice.

Finally in these circumstances where non-flammablesolvents are required to be used for extraction of organicsfrom sludges environmentally safe chloro-floro-carbonsmay be used.

6. Application/Market CharacteristicsThe Company is positioned in the segments of the

hazardous waste treatment market where removal of or-ganic material from liquids, soils, and sludges is required.Among the benefits to the user are:

reduction of wastes to small residual volumessuitable for land disposal;elimination of the legal and financial liability ofoff-site disposal in many cases;recovery of organic material with value as aproduct or fuel; anda cost-effective alternative to the next best tech-nical option, incineration.

A major additional advantage is the absence of RCRApermitting requirements in most markets. Under RCRA,treatment systems usually operate under permits to ensurethat the treatment itself will not represent a hazard. Incin-eration, for example, requires permitting and the concomi-tant requirement for public hearings is delaying incinera-tion capacity by 3-5 years.

CF Systems’ permit exemptions fall under three cate-gories:

the recycling exclusion, where a useful by-prod-uct is produced (e.g., petroleum refineries);wastewater pretreatment exemption, where theCF Systems unit is a pretreater to final wastewa-ter treatment. as in chemical plants;

l the “totally enclosed” treatment system exclu-sion, for contained units such as the Company’sproducts.

Superfund SitesThe EPA’s inventory of potentially hazardous sites

throughout the United States has been stated as greater than25,000 [2] in number. By the spring of 1989, about 900 ofthese sites had progressed through the evaluation stage tothe point where they were on the National Priorities List(NPL) and subject to enforcement action under CERCLA.In anotherreport, the General Accounting Office estimatedthe universe of potential hazardous waste sites at some-where between 130,000 and 425,000 [3] . Whicheverfigure is used, it is clear that substantial resources will bededicated to the clean up of old hazardous waste disposalsites for some time to come.

Using refinery experience as a reference, it is esti-matedthat theaverageSuperfundsitemightcontain50,000-100,000 tons of material and that about 150 applicable siteswill be remediated by 1993. On this basis, the Superfundtonnagetreatedin theperiod 1989-1993 mightbe7.5 to 15million tons of material.

6.2 Petroleum Refining Wastes

Of the approximately 180 petroleum refinery sites inthe United States, about 100 are active and 80 have shutdown. Canada has about 50 refineries (active plus inac-tive).

Refineries have two primary categories of waste treat-able by this technology:

l oily sludges produced from current operation,(ongoing wastes) such as API separator sludges(40 CFR 261.32 K048-K052).

l oily sludges and solids from past operationsstored in pits, ponds, and lagoons (surface im-poundments).

Ongoing wastes are subject to the RCRA land ban inAugust, 1990. While some refineries may gain furtherdelays, current environmental control activity clearly indi-cates that many refineries are preparing to have treatmentcapacity in place by that time.

The average active refinery in the U.S. is estimated toproduce 3-5,000 tons per year of listed hazardous wastes(predominantly API separator sludge) subject to the 1990land ban; as well as additional wastes listed by states suchas California, and contaminated soils, which will total 2.5million tons over five years.

47

Closure plans for impoundments will be implementedin the refining industry over the next 10 years at active aswell as inactive sites. Most refineries have pits or surfaceimpoundments containing waste sludges generated in thepast. In the U.S. and Canada, it is estimated that the totalof these impoundments exceed 10 million tons.

6.3 Incinerator Pretreatment

Less than 10 RCRA-permitted incinerators for de-struction of solid hazardous wastes presently exist in theUnited States. The demand for such incinerators far out-strips the supply, but are slim because of public oppositionto permitting, the prospects for closure of that gap soon.Thus, any means for increasing the throughput of existingincinerators is of obvious value.

A significant fraction of solid hazardous wastes con-tains organic liquids that can be extracted with a CFSystems unit. This extraction, as a pretreatment, producesan incinerator feed with reduced heat content (BTU perpound of feed). Incinerator capacity is limited by the heatthat canberemoved (BTU), not the pounds of feed flowingthrough. Thus, a controlled evolution of the heat contentallows more pounds of hazardous waste to be destroyed.Moreover, the extracted liquid fraction can be used as fuelin the so-called secondary burn, which would otherwiserequire purchased fuel. As a result, the incinerator operatorgets a double benefit from CF Systems’ pretreatment.

7. Remediation Experience HistoriesCF Systems has generated process and equipment

design information for applications in the hazardous wastetreatment and remediation industry. A substantial data-base has evolved for a wide range of extractions fromsponsoredresearchconductedatourbench-scaleandpilot-plant facilities. Continued growth of that database andprocess correlations is on-going in our research facilities.

As noted earlier, CF Systems’ extraction technologyhas been successfully demonstrated in the field. The 20barrel-per-day MDU successfully started-up in 1987 at theTexaco refinery in Port Arthur, Texas. Since then, the unithas processed a wide variety of wastes at several refineries,chemical plants, and TSD facilities in North America.These include:

Texaco, Port Arthur, TexasChevron, Salt Lake City, UtahChevron, Perth Amboy, New JerseyBASF, Keamy, New JerseyPetro-Canada, Montreal, CanadaTricil, Toronto, CanadaNew Bedford Harbor Superfund NPL Site.New Bedford, Massachusetts

2. BASF. Keamv. New Jersey

Exxon, Baton Rouge, LouisianaUnocal, Parachute Creek, ColoradoUnited Creosote Superfund NPL Site,Conroe, Texas

Texaco.Port Arthur.October. 1987-Januarv. 1988The MDU had its initial operation at Texaco’sPort Arthur refinery in late 1987. A range ofdifferent feed types were run through the system,including spent oily clay, primary separatorsludge, and tank bottoms. The resulting treatedsolids product streams wereanalyzed by Texaco,and representative results are shown in Table7-l. Performance consistently met what laterbecame BDAT standards for RCRA first- third(KO48-K052)refinery wastes. Theresultsofthisdemonstration led Texaco to award CF Systemsa contract to provide a commercial unit toremediate 20,000 cubic yards of primary separa-tor sludges.

A mobile treatment system was run at the BASFKeamy, New Jersey, plant site. One of the wastestreams from this plant is an emulsified streamcontaining di-octyl phthalate (DOP), water, andother organic materials. The system success-fully separated the emulsion into a recoverableDOP stream and a wastewater suitable for dis-charge to the wastewater treatment facility.

3. Petro-Canada. MontrealThe MDU operated at Petro- Canada’s Montrealrefinery for a six-week period. During this time,the unit successfully processed 14 different feedtypes ranging from API separator sludges tocontaminated soils. The unit achieved organicremoval levels better than existing BDAT stan-dards. In some cases, the levels of residualorganics, both volatile and semivolatile, werebetter than those obtained with incineration.

4. Tricil. Toronto. CanadaA series of demonstration tests were run at TricilCanada’s TSD facility in Missasauga. Ontario.The system de-oiled a majority of the organicfeed materials arriving at this facility. The wastesprocessed included API separator sludge, paintwastes, synthetic rubber process waste, and coaltar wastes.

48

Table 7.1. Texaco Port Arthur Performance Data.

Ditch Skimmer(LAB) Clay Pit Area (MDU)Boat Feed Treated TCLP Feed Treated

Levels Solids Solids

(mg/Kg) (mG/Kg) (mg/Mg) (mg/L) (mg/Kg) (mg/Kg)Water (WT. %)

SITE 127 Sludge (MDU) SITE 143 Sludge (MDU) Ditch Skimmer (MDU)

Solids (WT. %)

Oil (WT. %) 3.1

Total Oil

& Grease

(WT. %, Dry)

Benzene 9.5 5.1

Ethylbenzene 67 13

Toluene 9.5 52

Xylenes Reserved 71

Fluorene

Naphthalene Reserved 50

2-Methyl Naphthalene

Phenanthrene 7.7 20

Ohromium 400

Lead 1100

60.5

22.3

17.2

Water

(mg/L)

Feed TreatedSolids

(mg/Mg)( mg/Kg)62

32

6

TCLP Feed Treated Feed Treated TCLPSolids Solids

(mg/L) (mg/Mg) (mg/Kg) (mg/Kg) (mg/Kg) (mg/L)57

33

10

53

35

12

0.052 1.9 3.6

0.06 <0.0005 9.6 <0.1 <0.01 <2.0 <2.0

0.13 <O.OO1 13 <0.1 <0.01 <2.0 <0.1

0.44 0.0027 16 <0.1 <0.01 <2.0 <0.1

0.59 <0.003 63 <0.1 <0.01 <2.0 < 0.1

0.1 0.0005 210 <5.3

300 <5.3

0.16 0.0015

560 0.02

1300 31

<50 <3.3

31 <3.3

<0.01 13.7

<0.01 20.2

<0.01 54.4

<0.01 75.9

45

30

1.0 0.7

<2.0 5.1 <0.1 <0.01

<0.1 13 <0.1 <0.01

<0.1 52 <0.1 <0.01

<0.1 71 <0.1 <0.01

9.3 <0.20

<3.3 16.5 <0.20

<3.3 18.6 <0.20

400 560 0.02

1100 1300 31

Two specific Tricil requirements were achieved:

l a large volume reduction of the wastes proc-essed;

l reduction of the level of volatile organics such

that land disposal of the residual solids wasacceptable.

5. New Bedford Harbor Superfund NPL Site. NewBedford. MassachusettsCF Systems participated in the EPA SuperfundInnovative Technology Evaluation (SITE) pro-gram at New Bedford Harbor in Massachusetts,a location which is heavily contaminated withPCB’s. Data obtained during the program indi-cated that it is feasible to obtain PCB removalto levels in excess of 99.9% at economic costs.

6. Unocal. Parachute Creek. ColoradoThe MDU completed a series of demonstrationsat Unocal’s Parachute Creek, Colorado facility.

Table 7.2. Conroe Performance DataFEED

COMPOUND DRY SOIL (MG/KG)

Acenapthene 360

Acenaphthylene 15

Anthracene 330

Benzo(A)anthracene 100

Benzo(A)pyrene 48

Benzo(B)fluoranthene 51

Benzo(GHl)perylene 20

Benzo(K)fluoranthene 50

Chrysene 110

Dibenzo(A,H)anthracene ND

Fluoranthene 360

Fluorene 380

Indeno(l,2,3-CD)pyrene 19

Naphthalene 140

Phenanthrene 590

Pyrene 360

Total Pah Conc. (MG/KG) 2879

Among the wastes successfully run weresamples of shale-oil wastes, drilling muds, andother process and refinery wastes.High recovery of good-quality oil was obtainedfrom shale-oil wastes. Drilling mud wastes weretreated to the standards required for land dis-posal.

7.United Creosote Superfund NPL Site,Conroe, TexasThe MDU completed a treatability study for theTexas Water Commission in conjunction withRoy F. Weston at a Superfund Site in Conroe,Texas. The objective of this study was to evalu-ate the effectiveness of solvent extraction forremediation of soil contaminated with creosote.PAH concentractions in the soil obtained fromthe capped area were reduced from 2879 ppm to122 ppm, demonstrating 95+% reductions werepossible. Representative results from this studyare shown in Table 7-2.

RAFFINATEDRY SOIL (MG/KG)

3.4

3.0

8.9

7.9

12

9.7

12

17

9.1

4.3

11

3.8

11

1.5

13

11

122.6

50

8. Remediation ServicesIn general, remediation projects encompass excava-

tion, treatment, and removal of contaminated soils andsludges (Figure B-3). Depending upon the types of con-tamination and the level of cleanup required, further proc-essing downstream of CF Systems' extraction system maybe necessary. This further processing may include fixationfor heavy metals and incineration of the extracted organics.

A typical remediation project may consist of the fol-lowing steps or any combination of these steps:

1. The soil is excavated and/or the slurry is dredged.2. If necessary, the excavated material is slurried

with water to create a pumpable mixture.3. Theslurry ispassedthroughamultilayeredshaker

screen to remove material larger than l/8-inchdiameter. Oversized material may be crushedand recycled to the screens.

4. The pH of the screened slurry is monitored and,if required, lime is added to the mixture to main-tain a pH between 6 and 8.

5. The slurry may require thickening prior to theslurry being pumped to the CF Systems Extrac-tion Unit.

6. Two product streams exit the Extraction Unit; asolids/water stream and a liquid organic stream.The organic stream will generally be returned tothe Client for reuse or disposal.

7. The solids/water stream is dewatered throughthe use of a belt filter press or a centrifuge. Thewater from the dewatering step may be used toslurry dry feed solids. Any excess water is cleanenough to be disposed of in domestic sewers orin a waste water treatment plant.

8.The dewatered solids may require chemicalfixation, if there are significant quantities ofleachable solids, such as heavy metals, so that thetreated solids may be disposed of in a non-hazardous landfill.

9. The treated solids must then be transported toand disposed of in a landfill or other suitable site.

8.1 Excavation and Feed Pretreatment8.1.1 Dry Soils

Contaminated dry soils will be excavated through theuse of equipment such as front end loaders, backhoes, orbulldozers. These soils will then be fed into a preliminaryscreening device to remove any materials larger than 4inches in diameter. Solids captured in the screens will becollected, washed, and disposed of inanappropriate manner.

Screened material will be transported on a conveyorbelt to a pug mill where size reduction is effected. The pug

mill will combine the dry solids with water to produce asolids/water extricate. This paste will then travel via asecond conveyor belt to a tank or pump where additionalwater will be added to produce slurried solids.

8.1.2 Sludges

A diesel engine powered, auger head dredge willslurry the waste sludges for pumping with water eitherpresent or added. Water addition is required in areas wherethe waste is partially solidified. If water addition isnecessary, enough water will be added to float the dredge,creating a pond area that the dredging operation willexpand.

8.1.3 Solids Screening and Thickening

Slurried solids from either the pug mill or the dredgewill pass through a multilayered shaker screen similar tothose used in the oil drilling industry. The objective will beto screen out solids larger than 1/8 inch in diameter. Solidscaptured by the screen will be collected, washed, andrecycled to the pug mill or crusher/grinder for size reduc-tion.

Sludge passing through the screen will be collected ina storage tank equipped with mixers. If required, lime willbe added at this point to maintain a pH between 6 and 8.The slurry will then be pumped from this tank to either theextraction unit or to a thickener.

If pumped to a thickener, the slurry will be thickenedto approximately 50-percent solids. This is accomplishedthrough the use of either a moving screen or a decantationsystem depending on the water solubility of the waste.

Water extracted by the thickener will be returned to thedredge area or to another approved discharge point. Thethickened solids slurry will be pumped to another holdingtank and then fed to the Extraction Unit.

8.2 Product Disposal

The de-oiled solids and water produced from the ex-traction process will be dewatered. This stream will be runthrough a belt filter press where a combination of pressureand conditioning flocculents, if required, will removeexcess water, leaving a cake with approximately 40- to 45-percent solids. Water separated from the slurry will bereturned to the dredge area or to the water treatmentsystem. De-oiled solids in the form of a cake will move viaconveyer from the belt filter press to a small blending mill.

9. Cost Estimate for a Specific SuperfundApplication

Cost estimates provided here are CF Systems’ stan-dard budget estimates quoted to commercial customers foruse in planning, scoping, and inviting of firm bids. The

51

estimates’ accuracy basis is +/- 20% of the expected finalquotations given the same basis and assumptions. CfSystems would utilize subcontractors to do portions of thedescribed work, specifically solids handling before andafter the key extraction step. However, CF Systems iswilling to provide the services under a user/project man-ager or under a prime contractor/project manager.

9.1 New Bedford Harbor, Massachusetts Clean UpCase Study

CF Systems has prepared cost estimates for two casesto provide solvent extraction technology to cleanup PCB-contaminated silt at New Bedford Harbor, Massachusetts.The following comprises the Scope of Work and the basisfor the cost estimate for the two cases.

9.1.1 Estuary Case Description

The quantity of material to be cleaned in Case 2 is695,000 cubic yards of PCB-contaminated soil. Thisquantity of material represents removal and treatment of allcontaminatedsoil in the New Bedford Harbor estuary. Thelevel of PCBs in this material is assumed to average 580ppmonadry solids weightbasis. The PCBs in thismaterialwill be reduced to 50 ppm via solvent extraction. The timeschedule for processing this material is about five years.

9.1.2 Case 1: Hot Spot Case Description

The quantity of material to be cleaned in Case 1 is50,000 cubic yards of PCB-contaminated soil. This quan-tity of material represents removal and treatment of the hotspots in New Bedford Harbor. The level of PCBs in thismaterial is assumed to be 10,000 ppm on a dry solidsweight basis. The PCBs in this material will be reduced to10 ppm on a dry solids weight basis via solvent extractiontechnology. This represents a 99.9% removal of PCBs.The time schedule for processing this quantity of materialis approximately one year.

9.2 Scope of Work

The scope of work for both cases described above is asfollows:

l.The PCB-contaminated material has been re-moved from New Bedford Harbor and stock-piled, by others, at an appropriate site on land.

2.CF Systems will move the contaminated soilsfrom the stockpile to its processing site, usingtypical heavy-duty earthmoving equipment suchas backhoes and bulldozers.

3.CF systems will screen the material to removeoversize particles. Solids larger than l/8” will beretained on the shaker screens, then be sent to acrusher/grinder for size reduction. Solids thatcannot be reduced in size will be rejected and

returned totheclient, who will beresponsiblefortheir disposal.

4. CF Systems will slurry and pretreat the screenedmaterial before it is processed in the solventextraction system.

5. CF System will process the pretreated feed in itssolventextraction units to remove thePCBs fromthe material.

6. Exiting the extraction system will be two productstreams: a PCB-rich extracted organics streamand a PCB-free solids/water stream. The PCBstream will be returned to the client for disposal.CFS ystems will dewater the solids/water streamand stockpile the solids for disposal by theclient.

9.3 Basis for Costing

CF Systems will provide the solvent extraction systemfor the cleanup of New Bedford Harbor. All auxiliary andsupport equipment required will be supplied by CF Sys-tems through subcontractors. It should be noted that thepreand post treatment equipment will be assumed to operateonly 10 hours per day. Sufficient storage capacity both inthe front and back will be assumed so that the extractionsystem can operate uninterrupted, 24 hours per day. Thecurrent cost estimate for the two cases assumed 1989 costsfor the subcontracted services. A breakdown of the sub-contracted items and the cost basis for these items are asfollows:

Solids Handling Equipment:The solids handling equipment is provided to move

the PCB contaminated material from the stockpile to theCF Systems treatment site. Equipment required for thisoperation is assumed to include:

One( l)Frontend Loader . . . . . . . . . . . . ..I.............. .$5OO/day

One( Bulldozer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $l,lOO/day

Two(2)25Ton Trucks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $2,OOO/day

Safety equipment for the operators is included in theabove costs. The above equipment is required for theduration of the job and is assumed to be operating 10 hoursper day.

Solids/Sludge Delivery Equipment:The solids/sludge delivery equipment is provided for

size reduction and delivery of the solids to the feed pretreat-ment system. Equipment required for this operation isassumed to include:

One (1) Frontend Loader . . . . . . . . . . . . . . . . . . . . . . . . . . .$ 5OO/day

Two (2) Pug Mills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . !§l,OOO/day

One (1) Crusher/Grinder. . . . . . . . . . . . . . . . . . . . . . . . . . . $ 750/day

Four (4) Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 200/day

Safety Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 80/day

The above equipment is required for the duration ofthe job and is assumed to be operating 10 hours per day.

Feed Pretreatment Equipment:The feed pretreatment equipment is provided to screen

and slurry the feed prior to the solvent extraction system.Equipment required for this operation is assumed to in-clude:

Two (2) Shaker Screens . . . . . . . . . . . . . . . . . . . . . . . . . $ 40/day

Two(2)) Clarifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 74/day

Two (2) Feed Pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 52/day

Two (2) Mud Tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $90/day

Two (2) Fractionating Tanks . . . . . . . . . . . . . . . . . . . . . . $ 200/day

The above equipment is required for the duration ofthe job.

Product Handling Equipment:The product handling equipment is provided to re-

ceive the product streams from the extraction system anddeliver these product(s) to the client for disposal. Equipment required for this operation is assumed to include:

Two (2) Filter Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .$ $800/day

Two (2) Liquid PCB Storage& Transfer System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .$ $4 10/day

Two (2) Solids/Water Storage& Transfer Systems.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ $160/day

Two (2) Conveyors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 30/day

One (1) Front-End Load. . . . . . . . . . . . . . . . . . . . . . . . . . . . .$ 500/day

One (1) D6 Bulldozer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $1,100/day

Theaboveequipment isrequiredforthedurationofthejob.

Facilities:The following site facilities are provided to support

the site personnel and equipment.

One (1) Sanitary/Office Trailer.. . . . . . . . . . . . . . . . ..$ 80/day

One (1) Laboratory Trailer . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 50/day

Site Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 300/day

Analytical Services . . . . . . . . . . . . . .._........... . . . . . . . . . $ 500/day

Two (2) Electrical Generator Sets . . . . . . . . . . . . . .$ 600/day

Two (2) Packaged Cooling Towers . . . . . . . . . . ..$ 200/day

Safety Clothing for Personnel(per man cost)... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $40/day

Utilities:It is estimated that all the equipment on-site (extrac-

tion systems and auxiliaries) will consume approximately2750 kwh/hr giving a cost of $3,960 per day for electricalconsumption at $0.06 per kwh for the estuary base case.

Labor:The following labor and current ( 1989) rates for super-

vising and operating the various operations have beenincluded in the cost estimate:

Supervisors for CF SystemsExtraction System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..$ 720/day

CF Systems’ ExtractionSystem Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $1,8OO/day

Pre/Post Treatment Operators . . . . . . . . . . . . . . . . . . . . . $ $600/day

Site Engineer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 300/day

Site Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ $400/day

Other Labor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 200/day

Safety Equipment for Above Personnel $ 720/day

9.4 Actual Cost Estimates

The specific costs for the two cases are tabulated inTable B-l. CF Systems utilized its proprietary in-housecost model and generated costs for each of the steps listedin the scope of work. The extraction only related costs werebroken out and tabulated according to the 12 cost elementsdefined by the EPA. Pre- and post-treatment costs involv-ing most of the rental equipment for solids handling werelumped together and some details provided on a confiden-tial basis to allow total system analysis. The contingencyand project management fees are self-explanatory.

53

Table B-l. CF Systems Budget Cost Estimates

Facilities (Wudlna utilities) Base CaseEstuarv

Facilities $ 5,170,676

CFSSite Preparation (1) $ 2,307,849PCU Capital Charges $ 37,027,058Labor $ 8,202,600Utilities $ 13‘053,273Analytical $ 1,519,000

Total Extraction Costs $ 62,109,781

Pre/Post TreatmentSite Preparation (1) $ I ,495,200Excavation/Solids Handling $ 16,405,200Solids Delivery $ 9,326,660Feed Pretreatment $ I ,974,700Product Handling/Post Treatment $ 6,957,020Utilities $ I ,749,888Labor $ 8,263,360

Total Other Costs $ 46,172,028Total Job Costs $113,452,485

Contingency (10%) $ 11,345,248Project Management (5%) $ 5,672,624

Overall Budget Cost of Remediation $130,470,358

(1) Includes mobilization, startup and demobilization

Hot

$ 762,496

$ 2,616,261$ 9,555,141$ 1,854,720$ 1,607,573$ 224.000$15,587,695

$ I ,297,800$ 2,419,200$ 1,375,360$ 291,200$ 1,025,920$ 258,048$ 1,326,080$ 7,993,608$24,613,799$ 2,461,380$ 1,230,690

$28,305,869

9.5 Description of Extraction System as Costed

9.5.1 Estuary Case 2

For this case, which involves a large tonnage removalformultipleyearson-site,CFSystemsrecommendsthe useof a custom made PCU-2000 system which will processabout 500 tons/day.

The total time on-site will be 8.35 years to remove thePCBs in 695,000 cubic yards of waste from 580 ppm to the50 ppm level (91.4% removal efficiency).

9.5.2 Hot Spot Case 1

For this case, CF Systems recommends the use of 4identical modular systems called PCU-500s which wouldcomplete the remediation in about 1.2 years. These areapproximately 125 ton/day units each having its own set ofextraction stages and a solvent recovery section.

The selection of this size unit and system configura-tion is to minimize total time on-site and total job cost. Twounits in series are required to meet the required efficiency(99.9%) i.e., PCB removal from 10,000 ppm to 10 ppm.Two sets in parallel are required to handle the total volu-metric throughput.

54

Appendix CSITE Demonstration

IntroductionSediments were dredged from five New Bedford

Harbor locations and stored in 55-gallon drums for proc-essing by the PCU-20. Drummed sediments were sievedto remove particles greater than one-eighth inch that coulddamage system valves. Water was also added to producea pumpable slurry. The drummed sediments were blendedto provide feedstocks for four tests.

Test 1 was a system shakedown run to set flow ratesand operating pressures and to provide samples for labora-tory evaluation of sample matrices. Samples were col-lected during Tests 2.3, and4 to provide data for evaluatingthe system’s performance. A fifth test was run with tolueneused as a feedstock for decontaminating the PCU. About1 to 2 hours were required to run a feedstock through thePCU. Test 2 involved passing, or recycling, the feedstock10 times. Test 3 involved 3 passes and Test 4 involved 6passes. Recycling was conducted to simulate the designoperation of a full-scale commercial system. The PCU isonly a two-stage system, whereas commercial designsinclude four or more stages, longer extractor residencetimes, and longer phase separation times. Conditions thatvaried for each test were:

1 Test 1 was run as a shakedown test to set pressureand flowrates in the PCU. The feed was a 50-gallon composite of sediments taken from drumnumbers H-20, H-21, and H-23. The feedhad a PCB concentration of 360 ppm.Three passes were run to gain experience withmaterials handling.

2. Test 2 was a 10 pass test. The feed was a 350ppm, 5 11 pound composite of sediments takenfrom drum numbers H-20, H-21, and H-23. Tenpasses were run to simulate a high-efficiencyprocess and to achieve treated sediment levelsless than 10 ppm. A 350 ppm concentration waschosen for this test since this represents an aver-age, or typical, PCB concentration in the harbor.

3. Test 3 was a 3 pass test. The feed was a 288 ppm,508-pound composite of sediments taken from

Results

drum numbers H-20, H-21, and H-23. The pur-pose of this test was to reproduce the results ofthe first three passes of Test 2.

4. Test 4 was a 6 pass test. The feed was a 2,575ppm, 299-pound composite of sediments takenfrom drum numbers I-l 1 and H-22. The pur-pose of this test was to reduce a high-level wasteto a lower level waste such as that used in Tests1, 2, and 3. High-level wastes are found atseveral “hot spots” in the harbor.

Decontamination of the system involved running tolu-ene through the PCU as a solvent wash. Samples weretaken of the feed at the commencement of each test.Treated sediment products and extracts were planned forsampling at each pass. Additional samples were taken ofsystem filters and strainers, although the amount of PCBcontained in these miscellaneous samples later proved tobe small. PCU operating pressures, temperatures, andflow-rates were monitored throughout the tests. Fieldtestswere conducted for feed viscosity, pH, and temperature.

ResultsA large amount of analytical and operating data was

obtained, and it was sufficient to meet the program objec-tives. The detailed results and operating summaries are inthe Technology Evaluation Report. The objectives indi-cated an evaluation of (1) the unit’s performance, (2)system operating conditions, (3) health and safety consid-erations, and (4) equipment and system material handlingproblems.

System PerformanceThe evaluation criteria established for system per-

formance were:

PCB concentration in sediments before and aftertreatmentPCB extraction efficiency with each pass ofsediments through the PCUMass balances established for total mass, solids,and PCBs.

55

These criteria are discussed with respect to analyticalresults below.

PCB Concentration Reductions

PCB analyses for feed sediments and treated sedi-ment, conducted for samples collected at each pass, areshown in Table C- 1. The data are displayed graphically inFigures C.l, C.2, and C.3. The data show that treatedsediment concentrations of 8 ppm are achievable and thatas much as 84 percent of the PCB contained in sedimentcan be removed in a single pass. In Test 2, feed containing350 ppm of PCB was reduced to 8 ppm after 9 passesthrough the PCU. In Test 3, a 288 ppm feed was reducedto 47 ppm after just one pass. In Test 4, a 2,575 ppm feedwas reduced to 200 ppm after 6 passes. The percentreductions in PCB concentration, based on a comparison ofuntreated feed to the final pass, for each test were:

Percent ReductionTest in PCB Concentration

2 89%

3 72%

4 92%

Table C-l. Pass-by-Pass PCB

Number ofPasses

10

3

6

The data for each test show general reduction trendsbased on differences between initial feed and final treatedsediment concentrations. However, these trends are notconsistent on a pass-by-pass basis. For example, PCBconcentrations in treated sediments increase at Test 2,passes 4 and 10, and at Test 3, passes 2 and 3. Theseanomolies are not related to the extraction process. In-stead, they reflect cross contamination within system hard-ware or limited analytical precision and accuracy. Sincethe treated sediment collection tanks were under pressure,it was not possible to clean out collection hardware andpiping. Therefore, a pass-by-pass mass balance could notbe established.

Data for each test can be used to construct a curve thatshows the potential number of passes required to reducePCBs in harbor sediments to specific concentrations usingthe Pit Cleanup Unit (PCU). If data from Test 2,3, and 4are displayed side-by-side, such that similar concentra-tions coincide, then a PCB reduction curve can be plotted.Data are displayed below, side-by-side, so thatsimilarconcentrations overlap.

Concentrations and Reduction Efficiencies

Test Pass PCB Concentration*Number _Number m

2 Feed 3502 1 772 2 522 3 202 4 662 5 592 6 412 7 362 8 292 9 82 10 40

3 Feed 288

: 2 1 47 723 3 82

4 Feed 2,5754 1 10004 2 9904 3 6704 4 3254 5 2404 6 200

*PCB data represent feed and treated sediment concentrations.

56

Pass-by-Pass ConcentrationReduction Efficiency

Ipercenti

Not Applicable783262

No Reduction1131121972

No Reduction

Not Applicable84

No ReductionNo Reduction

Not Applicable61

132522617

151 1 PC0 Reduction

Figure C- 1.

Test 3 PCB Reduction

Figure C-2.

Q

2.1 -

2 . 6 -

2 . 4 -

2.2 -

1-

1 . 6 -

1 . 6 -

1 . 4 -

I.2 -

I -

0 . 6 -

0 . 6 -

0 . 4 -

0 . 2 -

a

Figure C-3.

57

Test 4

2,5751,000

990670325240200

Pass-by-Pass PCB Concentrations

Test 3 Test 2

288 35047 7772 5282 20

6659413629

840

Based on the presentation of the data in Figure C.4, itcan be construed that harbor sediments containing 2,500ppm of PCB could be reduced to 100 ppm after 6 passesthrough the PCU. A level less than 10 ppm may beachievable after 13 passes.

Extraction EfficiencyPass-by-pass PCB concentration extraction efficien-

cies are shown in Table C-l and are calculated as PCBextracted divided by concentration at the beginning of thepass (multiplied by 100 percent). For each test, the firstpass results in efficiencies greater than 60 percent. How-ever, at later passes efficiencies range from negativevalues to 72 percent. This wide range is the result of cross-contamination of solids retained in the treated sedimentsubsystem.

Data show that the system irregularly retained anddischarged treated sediments. For somepasses,as much as50 percent of the feed was retained in the system. That feedwas treated sediment that clung to internal piping and tanksurfaces. If discharged with a later pass, the combineddischarge could have a higher concentration than feed forthe later pass. For example, assume an extraction effi-ciency of 60 percent, a feed concentration of 350 ppm, anda carry-over of solids from the first pass to the second passof 25 percent. Then, the treated sediment would contain77 ppm, instead of 56 ppm if no cross contamination

was contained in the extract subsystem, not the treatedsediment subsystem.

Mass BalancesTotal mass, total solids, and total mass of PCBs were

determined for various system inputs and outputs for thepurpose of establishing a mass balance. Figure C.5 depictsthe inventory sheet used to account for system input andoutput. Input included feed material and water, althoughsome feed was lost to sampling, sieving, spills, and residu-als remaining on the surface of the feed drums. Outputsfrom the system included samples, spills, container residu-als, treated sediment, and residue collected on the basketstrainer and cartridge filter. The difference between inputand output resulted in either accumulations within thesystem or unaccounted-for discharges of accumulatedmaterial from the system. Mass inventories were devel-oped for each test.

PCB BalanceTable C-2 illustrates the fate of PCB on a pass-by-pass

inventory basis. The system accumulated 15.15 gramsduring Test 2.6.71 grams during Test 3, and 42.11 gramsduring Test 4. Only an approximate PCB balance ispossible for Test 1, since Test 1 was a shakedown test only.Approximately 21 grams of PCB accumulated within thesystem during Test 1. Thus, total accumulation within thesystem from Test 1 through Test 4 was about 85 grams(where 84.96 = 15.14 + 6.71 + 42.11 + 21).

The fuel wash, which occurred immediately after thefirst pass of Test 3, flushed 35 grams of PCB from theextract subsystem. Final system decontamination withtoluene wash delivered an additional 151 grams. Totalwash output was 35 plus 151, or 186 grams. Ideally, theamount of PCB washed from the system should equalamount accumulated, or

Accumulation - Wash = 0

However, in this case,

85 grams - 186 grams = 101 grams

The amount of PCB washed from the system is shownabove to be greater than the amount fed, which raises thepossibility that (1) sampling and analytical errors occurred,or (2) the system was contaminated from a previous CFSystems demonstration.

occurred. Quality control samples collected during the demon-

The occurrence of cross contamination affects inter- stration indicate the possibility of sampling and analytical

pretation of each test, but it does not invalidate the fact that error. For example, laboratory precision and accuracy

treated sediment concentrations as low as 8 ppm were criteria were 20 and 50 relative percent difference, respec-

produced. Furthermore, the decontamination procedure, tivcly. In addition, quadruplicate grab samples were col-

showed that PCB, which accumulated in system hardware, lected of the Test 3 feed, the Test 4 feed, and the Test 3

58

Table C-2. Mass Accumulation and Loss in the System

Test

2222222222

333

444444

123456789

10

Subtotal

lPoundsl

122

(2”557822

(Ey(7)

(16)9

254

123

Subtotal

24

z

111

(8;

(8y106

Subtotal (31)

TOTAL

Total Mass Total Solids Total PCBs

39

(4itii

(11)(3)m

40

(13)

4

14.210.700.50

(0.22)(0.07)0.30.04

(0.07)0.29

15.14

6.281.42

(i;94

$

14

6.71

37.79(5.25)8.722.551.63

42.11

Note: Parentheses indicate a loss or discharge from the system.

59

PCB Concentrat ion Reduct ion ModelAil Tests Combined

2 . 6 -

2 . 6 1

2 . 4 -

2 . 2 -

1,

1

2

.a

.6

0 . 6 -

0 . 4 -

0 . 2 -

0 1 2 3 4 5 6 7 6 9 10 I1 12 13 I 4

Extraction Poso No.m Test 4 + Test 3 & T e d 2

Figure C-4. Potential Pit Cleanup Unit PCB R e d u c t i o n

Inventory SheetT e s t Pass

1. Feed Material 6. Water

3. Strainer f-

4. Spills e

Residuals f-

17. Extract *

16. Spills

t

7. Total Feed 13. Water

b 12. Basket Strainer

9. Sampling

10. Spills

11. Residuals

14. Cartridge Filter

8. Treated Sediment Accumulations and Other Losses

Figure C-5. Illustrative Inventory Sheet.

61

treated sediment and the RPD calculated for each setranged from 12 to47 percent. In particular, the Test 4 feedhad a mean concentration of 2,575 ppm, which dominatesall other measurements used in the balance, and it had anRPD of 22. Another possible source of the PCB imbalancewas contamination of the PCU from prior use at anothersite. CF Systems did not decontaminate the unit withtoluene prior to this demonstration. CF Systems’ standardoperating procedures now incorporate decontaminationwith toluene.

In spite of the calculated PCB imbalance, a positiveseparation of PCB from the harbor sediments was accom-plished. The mass balances that 81 grams of PCB werecontained in sediments fed to the PCU in Tests 2,3, and 4.Resulting treated sediments contained 4 grams of PCB,which indicates a mass removal efficiency of 95 percent.Decontamination residue data show that some PCB accu-mulated in system hardware. However, 91 percent of thePCBs contained in decontamination residues were con-tained in the extract subsystem. The remaining 9 percentwas contained in the treated sediment subsystem hardware.

Basket Strainer, Cartridge Filter, and CarbonCanister

The basket strainer and cartridge filter, which gener-ate residuals that are normally discarded as a waste streamseparate from extract and raffinate, did not accumulate asignificant PCB mass. The mass balances, shown inAppendix A, show that the accumulation was approxi-mately 2 percent of the PCB mass fed to the system. Whencompared to PCB removals of 90 percent, this indicatesthat PCB removal by the basket strainer was not signifi-can& In addition, chemical analysis of the PCB content offiltered solids indicate that the concentration of filteredsolids associated with each pass roughly correlated withthe treated sediments from the previous pass.

Low pressure propane/butane was vented through thePCU carbon canister at the conclusion of the decontamina-tion procedures. The 285 pounds of activated carboncontained in the canister collected less than 1 gram of PCB.This indicates that air emissions are not significant andPCBs are separated from the solvent when expanded in thePCU.

Total Mass of SolidsThe PCU retained and discharged feed material inter-

mittantly throughout the tests. This behavior is demon-strated by tracking the sediment solids. The mass of solidsaccumulated on a pass-by-pass basis is significant. Theflow of solids per pass ranges from 55 percent accumulatedto 150 percent discharged. There is no consistent correla-tion between solids retention and PCB concentration re-duction.

During Tests 2,3,4, and 5 the system accumulated 302pounds total mass and 53 pounds total solids. Total massaccumulation represents approximately 4 percent of totalmass fed to system during Tests 2 through 5, and totalsolids accumulation represents about 7 percent of totalsolids fed to the system.

A total of 3-1/2 tons of solids and water were fed to theunit over the course of 19 passes throughout Test 2,3, and4. Of the total, 96percent was accounted for in the systemoutputs. Of 789 pounds of solids fed to the system, 93percent was accounted for in system outputs.

Other Data

Semivolatile OrganicsSystem feed, final treated sediment, and final extract

were sampled for base/neutral and acid extractable organ-ics (semivolatiles) during each test for the purpose of (1)characterizing materials for disposal and (2) observing anyextraction of semivolatiles. Interpretationof the semivola-tiles data, shown in Volume II, is limited for two reasons:(1) the unit contained sludges from a previous demonstra-tion at a petroleum refinery, and (2) a naphtha-based fuelproduct was added to the unit during Test 3 to clean out thestill, extract product tank and related hardware. Thefollowing conclusions can be drawn:

.

.

.

Semivolatiles detected in the toluene wash werealso detected in the feed drums, the source beingNew Bedford Harbor sludge.

Phenol and 2-methylphenol werefoundin treatedsediments and extracts but were not measured infeed drums, the feed kettle, or toluene washes.

Test 4 resulted in a reduction of 1,4-dichloroben-zene and pyrene, but chrysene and bis(2-eth-ylhexyl phtbalate) were increased. Similar in-consistencies occur for Test 2 and 3.

. 2-Chlorophenol, 1,3-dichlorobenzene, andbenzo(k)fluoranthene were fed to the unit butnot detected in any system effluents.

Fate of MetalsA fiim conclusion cannot be drawn concerning the

fate of metals after each test, since the unit tends toaccumulate solids. However, the data in Table C-3 showthat treated sediments metals concentrations generallyequal or exceed feed metals concentrations. The data alsoshow that metals were not extracted and discharged in theorganics effluent. Metals concentrations in organic ex-tracts were one to two orders of magnitude less than treatedsediments.

62

Q

Table C-3. Metals Content of Feed, Treated Sediment, and Extract

Test 2 Test 2 Test 3 Test 4Pass 3 Test 2 Pass 10 Test 2 Pass 3 Test 3 Pass 6 Test 4 Test 4

Test 2 Treated Pass 4 Treated Pass 10 Test 3 Treated Pass 3 Test 4 Treated Pass 4 Pass 6Parameter Units && Sedimenf .Q,& S e d i m e n t Extract Feed SedimentFxtract E& S e d i m e n t Fxtract F,xtract

Cadmium, ppm 35.7 32.5 44.0 42.8 NRNR 32.0 62.3 6(2) 87.5 120.0 5 5

Chromium, ppm 596 581 761 816 3 525 1020 20 1480 1790 26 31

Copper, ppm 1790 1650 1990 1740 5(2) 1320 2570 6(2) 2650 3700 5 4

Lead, ppm 619 587 792 892 NR(1) 520 1100 NR(1) 1300 1800 35 40

Zinc, ppm 2150 2220 2680 2610 5(2) 1900 3550 8(2) 5370 7260 15 15

Total Residue, % 23.3 18.2 15.0 9.4 NR(3) 19.4 10.3 NR(3) 16.4 5.6 NR(3) NR(3)

Notes: 1. Not reported, severe matrix effects.2. Matrix effects indicated.3. Not reported, insufficient sample volume for analysis method.

EP Toxicity Feed and Extraction Temperature

RCRA regulations at 40 CFR 261.24 specify testmethods for determining if a solid waste exhibits thecharacteristic of EP (extraction procedure) toxicity. Themaximum concentration ofcontaminants for the character-istic of EP Toxicity is shown in Table C-4. Also shown areanalytical results for (1) two samples taken from a com-posite of drummed harbor sediment collected by COEduring the waste presampling and (2) a sample of demon-stration Test 4, Pass 6 treated sediment. Concentrations foreach sample shown are less than the regulatory maximumfor the definition of the EP toxicity characteristic.

Feed and extraction temperatures were stable for Tests3 and 4. Feed temperatures ranged between 60 and 70degrees F while extraction temperatures ranged between60 and 80 degrees F. However, data for Test 2 indicate thatfeed temperatures fell about 15 degrees F below the mini-mum specification after pass 5. This caused extractiontemperatures to drop, with pass 9 falling 4 degrees F belowthe minimum specification, 60 degrees F. ,

The developer attributes much of the fluctuating ex-traction efficiencies calculated for Test 2 to the low feed

Table C-4. EP Toxicity Characteristics of Treated and Untreated SedimentsUnits (Parts Per Million)

Maximum ConcentrationComposite Sample of Treated Allowable for

Waste Presampling Drums Sediment Characteristics ofSamDle %UEQ!!Q

EP Toxrclty

ArsenicBariumCadmiumChromiumLeadMercurySeleniumSilver

0.011 0.008 <0..005 5.00.16 0.15 0.36 100.00.11 0.12 0.30 1.00.18 0.098 0.053 5.00.34 0.23 0.16 5.0

<0.0002 <0.002 <0.0002 0.2<0.005 <0.005 co.02 1.0<0.015 co.015 0.015 5.0

Note: < indicates detected less than the detection limit shown.

Operating ConditionsThe system specifications that CF Systems requires

for normal operation were discussed in Section 3. In thissection, observed operating conditions are summarizedand opemting data are interpreted with respect to treatmentefficiency. In tables throughout this section, mean operat-ing data are shown as well as the range of data recorded foreach mean value. Generally, the technology accommo-dated wide ranges of operating conditions, although pre-cise operational control was limited since all controls weremanual rather than automatic.

Extraction PressurePressures in both extractors used in the system were

fairly stable for all tests. Pressure levels were close to thenominal level of 240 psig. The maximum pressure, 285psig, was below the 300 psig maximum specification. Theminimum pressure, 190 psig, was above the 180 psigminimum specification. Because pressures were so stable.no relationship between extraction efficiency and extractorpressure was apparent.

temperatures, although other factors were probably impor-tant These factors include cross contamination in thetreated sediments collection tank. In addition, reentrain-ment of solvent in decanter underflows may have causeddisproportionately large effects on low concentration sedi-ments. Each factor must be addressed by the developer inthe design of a full-scale system.

Feed Flow RateThe feed flow rate ranged consistently, throughout the

tests, from 0.6 to 1.4 gpm. This range compares well withthe 0.2 gpm minimum specification and the 1.5 gpmmaximum specification.

Solvent Flow RateThe solvent flow fluctuated outside the minimum

specification, 8 lb/min, and the maximum specification. 15lb/min throughout Tests 2,3, and 4. Because of this wide

64

variation, it was suspected the flow meter was malfunc-tioning. In Test 4, an alternative measuring device wasused and flow measurements continued to show widevariations.

The variable solvent flows caused the solvent/feedratio also to fluctuate widely. This ratio was calculated assolvent (lb/min)/feed (gpm)/feed density (lb/gal). Theminimum solvent-to-feed ratio specification, 1 .0 , was notmet on Pass 2 of Test 4 based on mean data. Individualreadings frequently exceeded the 1.0 to 2.0 specificationrange. A pass-by-pass comparisonof solvent/feed ratios toextraction efficiencies was attempted but no direct corre-lation or trend was apparent.

Nonetheless, it is believed that the solvent/feed ratio isa significant factor in process design since the solubility ofan organic in liquified propane-butane is the fundamentalbasis for the extraction. With higher solvent/feed ratios,the feed is exposed to a larger amount of solvent andextraction efficiency should increase. However, theserelationships were not observed, given the available data.

Feed SolidsFeed solids content steadily declined during each test.

Initial feeds had solids contents ranging from 15 to 22percent. Final treated sediments ranged from 6 to 11percent solids. This change is primarily a result of wateradded to the feed kettle by operating personnel, duringeach pass. This unnecessary practice caused waste vol-umes to increase by 33 percent over the course of thedemonstration program. Another, but less significant,factor that affected solids content was accumulation ofsolids in system hardware. The solids mass balanceshowed that 7 percent of the solids accumulated in thesystem and were not washed out during decontamination.

Treated sediments that were fed to the unit after Pass3 of each test, had solids contents below the minimimspecification, 10 percent. Thisdilution of the feed materialis believed to affect system performance.

Viscosity and pHFeed viscosity and pH fell within specifications and

did not affect system performance. Viscosities for un-treated feed and recycled sediments ranged from 20 to 170centipoise, well below the 1,000 centipoise maximumspecification. This specification was set by the developeronly to ensure that the feed would be pumpable. Untreatedand recycled sediments had pH values that ranged between7.3 and 8.5 standard units. This narrow band fell within the6 to 12 specification range. The developer established thisrange t o prevent corrosion to PCU hardware.

Health and Safety MonitoringDuring the demonstration of CF Systems’ process

unit. personnel were potentially exposed to the contami-nated harbor sediments. A monitoring program was con-ducted to determine potential exposures and provide abasis for selection of p r o p e r personal protective equip-ment Several types of portable monitoring equipmentwere used during the v a r i o u s phases of the field investiga-tions, including:

Portable Organic Vapor Analyzer (Century OVA)Portable Photoionization Meter (HNu)Combustible gas/oxygen/hydrogen sulfide me-ters (MSA and Enmet-Tritector)Detector tubes and sampling pump (Sensidyne-Gastec)

l Personal air sampling pumps (Dupont-P200).

It was suspected that some level of organic vaporswould be encountered, particularly when drums contain-ing contaminated sediments were first opened during thefeed preparation phase, Continuous monitoring using boththe OVA and HNu instruments was conducted while thedrums were being opened. These instruments detected aslight elevation above background levels of organic vaporimmediately upon opening the drums. The levels returnedto background levels within a few seconds. No measurablelevels of hydrogen sulfide or combustible gas were en-countered while opening the drums or handling the sedi-ments during the feed preparation phase.

During the various test runs of the extraction unit at theNew Bedford site. organic vapors, PCBs, combustiblegases, and hydrogen sulfide were monitored. The OVAand HNu meters were used to monitor for organic vaporsat all work stations on the extraction unit, while CFSystems and SITE personnel monitored process equip-ment. The OVA also was used as a survey meter on theprocess equipment to search for possible fugitive emis-sions from the equipment. All measurements indicatedthat organic vapor levels remained in the range of back-ground levels. Two portable combustible gas meters wereused to check for elevated levels of propane during theequipment shakedown period and for spot testing duringthe demonstration. The pilot unit also contained twointegral combustible g a s detectors located on either end ofthe unit. During the normal extraction process, combus-tible gas readings remained at background levels. How-ever, while treated sediment and extract samples werecollected, the combustible gas meters indicated that levelsexceeding only 20 percent of the lower explosive limit forpropane were encountered These episodes of elevatedPropane levels generally lasted for less than 60 seconds and

65

subsided rapidly depending on the length of time samplingoccurred and the strength of the wind at the time.

Sampling was conducted using personal samplingpumps and 150-mg charcoal tubes and florosil tubes todetermine personal exposures to organic vapors and PCBs,respectively. All air sample results indicated that, ifpresent, organic vapors and PCB levels were present onlyat levels below the detection limits for the analyticalmethods. No measurable levels of hydrogen sulfide weredetected using either detector tubes or portable monitoringdevices.

Treated sediment and extract subsystems were decon-taminated with toluene. The final concentration of PCBcontained in the treated sediment subsystem toluene washwas 34 ppm, which was below the decontamination goal of50 ppm. The final concentration of PCB contained inextract subsystem toluene wash was 60 ppm, which slightlyexceeded the decontamination goal of 50 ppm. Stagingarea soils were not affected by any leaks or emissions thatmay have occurred during the duration of the demonstra-

day, but only 50 to 100 gallons per day were batch-fedduring shakedown on tests 2.3, and 4. Consequently, theunit irregularly discharged and retained solids with eachpass.

Previous use of the unit affected interpretation ofsemivolatiles data and may have contributed to imbalanceof the PCB inventory. Internal surfaces of extract collec-tion hardware collected PCBs as evidenced by mass bal-ances. In addition, Test 3 was interrupted and viscous oilswere found accumulating in extract subsystem hardware.PCBs are soluble in oil, which coated the internal surfacesof system hardware. The amount of oil that can coatinternal piping and collection tanks could be significant.For example, assume (1) a hardware surface area of 10square meters, (2) a coating thickness of 0.1 millimeters,and (3) an oil density of 1.0 grams/cubic centimeter. Thisis equivalent to 100 grams of oils that cling to the internalsurfaces of extract subsystem hardware. As a result of thisdemonstration, CF Systems now requires more rigorousdecontamination procedures for the PCU.

Solids were observed in extract samples that were

Equipment and Material Handling Problemsexpected to be solids-free. This indicates poor perform-ance or failure of the cartridge filter. An alternative type of

Equipment and material handling problems occurred filter should be investigated by the developer.throughout the demonstration. While these problems didnot impede achievement of the developer’s treatment

Low-pressure dissolved propane and butane caused

goals, they could impact the economic performance of afoaming to occur in the treated sediment product tanks.

full-scale commercial system. Some problems were an-This hindered sample collection and caused frequent over-

ticipated since relatively small volumes of sediments wereflow of treated sediment to a secondary treated sediment

batch-fed to a unit that was designed for continuous opera-product tank. CF Systems states that design of a commer-

tion. The nominal capacity of the unit is 700 gallons percial-scale unit will allow release of solvent entrained in thetreated sediment and elimination of the foaming problem.

e U.S. Government Printing Office: 1990 - 751-28766