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NVIRONMENTAE PROGRESS Pro$rs.ls U * prubtfilalkn of liiC American o( ClKjpipai IJpainusft, U wi(( deal ^v-idi mttlij- S] ,\iol KuiK'ih.iiion ol < niUinnin.ilvd Noils ;uu) (.rouiKlu.tlei s issik' Hjifcts oj mepommort p/wjm n win pmioo (OVfrtg* of JtoWriitrti, omirvi, aitd <ai(si;imcAX Robert W. liters, Guest luiUor ; .*.4 . i, .. . V.<1 ________ ... .,,i. . illwer all a5f>K including wait*, <f, liquid I Contents 4 wistbs. if.<J techiwtagit*! idvwvcti] .^ftviroiiincjtlalengineer will Iks rujxirtwf. Evolution of the Superfund Remedy Selection Process, Including an Assessment of JhJil<>Hf) Qijof .Mark|), Roseoxwolg Implementation of Permanent and Alternative Remedial Technologies Erik Dinemann, William Goldfarb and Robert C. Ahlert.......,,............... ............................. 165 . Editor Gary V. Rennrfl (419)5274520 PfO<l|i(,(ioii Director l)anU'i Chjllak ^ Managing Editor Maura N. Mullen ' (212)705*7527 ridiirtriaj A^Uisnis * Karen M. Simpson ^ Thomas K,H, Campbell Copy Editor / Arthur H, llaulvh ' Washington IidiKjr Martin W, Siegel Rook Review Rdlior * Robert W, Peters 5 S<>ffwate Review t Ashok Kumar Critical Evaluation of PCB Remediation Technologies Laura J. Amend and Peter D. Lederman.............................................................................. 173 Granular Activated Carbon Pilot Treatment Studies for Explosives Removal From Contaminated Groundwater W. J. Wujick, IP. L. Lowe, P. J. Marks and W.E. Sisk...........................................................178 Evaluation of a Hydraulically-Installed Suction Lysimeter to Obtain Representative Soil Water Samples Mark Chaimberg, RonaldH. Carty and Joseph A. Scroppo................................................. 190 Ultrasonic Destruction of Chlorinated Compounds in Aqueous Solution Jiann M. Wu, H. S. Huang and C. D. Livengood..................... ............................................. 195 Remediation of Dichloromethane (DCM) Contaminated Ground Water Paul E. Flathnan, Douglas E. Jerger atid Patrick M. Woodhuli.........................................202 Effect of Chemical Pretreatment on Anaerobic Biodegradation of Refractory Organic Compounds Yi-Tin Wang.............................................. ................................... .....................................210 Soil Decontamination via Microwave and Radio Frequency Co-Volatilization Clifford E. George, George R. Lightsey, Inchul Jun and Jiayi Fan..................................... 216 > Editorial Review Hoard ' Robed C. Ahlert R.U<? Ryers ' t/.R.Kilekson ' Randy Freeman ' Stephen C. James " Any .lefeoat ; ' Michael C, Kavanangh i William J. Lacy ; 1\ Lcdcrmajj R.Mahallngham Robert >V, Peters O.O, Reynolds O.J'/roniiiii J. A. Seller Richard D.Mcgel Wcl.OlilYlnR Supercritical Extraction of Polynuclear Aromatic Hydrocarbons from Soil S. Kothandaraman, R. C. Ahlert, E. S. Venkataramanl and A. T. Andrews.... The B.E.S.T. Solvent Extraction Process Treatment of Soil, Sediment, and Sludges George R. Jones.............. ...... ........ ......... .......... ........................ ............................ Pneumatic Pumping Test for Soil Vacuum Extraction Jong Soo Cho and Dominic C. DiGiulio.................................................................... Adsorption/Desorption Characteristics of Lead on Various Types of Soil Robert IP. Peters and Linda Shan............................................................ Electrokinetic Removal of Selected Heavy Metals from Soil Sibel Pamukcu and J. Kenneth Wittle.................................... puWisllOr ; Cary M.Rekstad < tn.ll i< n,,;,, imSald>wiuoftWte3:1o. ,,.1n4m7iwhvSixi.,ifNifemwtYPo/Av,zNwYs.Xl&Om&pWiWllKSeSmI. Had UvbrAminCwV^InSdiOUsibfiCheniicai liji^iicas ) ASjxinslbuity fcwlheriii'SolBCTijibim^pncepef 00. AKlhli ViivjtvfimcnUd DjvKi'on.McmbeKi 3d in dv; die US. mease add $12.wt lor }>6<i'iftge'ftlid'ii8ildllrig'Siigl6iii>j[>JcS' $34; the An)erieikAljBtjiw vf(AejiiJcalJjiglneecs; Foreword<<*<<V>>*:i:<V*V <>*) Editorial,,, ............... Environmental Shorts.: Book Reviews........... : Software Review :ttYm ^Mpidrherill >>:<<>V <?>V> V**> }t<V> Vij>:<<Vi{> | !1| A7 ^ Aio ; Reproducing copies: The appearance of tfc cock ai the bottom of this page Indicates the copyright owner's consent that for a stated fee copies of articles in this journal maybe made for personal or internal use or for the personal or internal use of specific clients. This caistni Is given co the condition thalthe copier pay the per-copy fee (appearing as part of the code) through the Copyright Clearance Center, Inc., 21 Congress St., Salem, MA 01970 for copying beyond that permitted by Section 107 or 108 of the U.S. Copyright Law. This consent does not extend to copying for general distri bution, for advertising or promotional purposes, for inclusion in a publication or for resale. Environmental Progress fee code: 0278-4491/9253.00. Postmaster: Please send change of addresses to Environmental Progress. AlChB, 345 Easl47lh Street, New York, N.Y. 10017. nmental Progress (Vol. 11, No. 3) August, 1992 .220 .223 228 .234 241 AI Science A r ommiltu' b Nmonsth uwativQ / Needs B-. ihleri, R. t : Naiion'i 1 lent Bulk D A nruuill hington, I1 or Haunt : Press, h Compeml \f Hazard*** 17. , "Evahmd, }emonslf' h Annual I Issues tion, chnology I eclwologhgR D.C., Si}^ @| sment, 'Ict^ udous IfV Critical Evaluation of PCB Remediation Technologies Laura J. Amend and Peter B. Lederman ' Roy F. Weston, Inc., Raritan Plaza 1, Raritan Center, Edison, NJ 08837 Polychlorinated biphenyls (PCBs) are a family of aromatic compounds consisting of a biphenyl molecule which has been chlorinated to form a large number ofpossible congeners. The number of chlorine atoms they can contain (from 1 to 10) varies, as does the placement of the chlorine atoms on the biphenyl molecule. Thus, a polychlorinated biphenyl is one of 209 compounds having the formula: C12//,0_nC/n. Due to their excellent heat stability, fire retardance and electrical insulating properties, they gained widespread use as I dielectric fluid incorporated in electrical transformers and capacitors. They were also incorporated in products as various as plastics, hydraulic fluids, surface coatings, inks, paints, pesticides, lubricants, and carbonless copy paper. nent,/lrt h Washinglc*^ INTRODUCTION Negative I. mi 1929 through 1980, the world production of PCBs was ?nt ReporkHs ohn Marlin rdinator, 2.4 billion pounds. It is estimated that in the United Unites, about 404 million pounds of PCBs are still in use and ^pN'cssible, about 262 million pounds are still in use add gen- not accessible, and about 585 million pounds have been ness Sec/fakl Rroyed or are in storage, landfills, or the environment. The still in use and accessible are in transformers, capacitors, al Proteill g?mi ther electrical equipment. Within the last category are ;r, 1988, 2*CBs in sediments, soil, vegetation and animals, the atmos- jre, and fresh water totalling about 24 million pounds, an- icr 13 million pounds are in the oceans, about 385 million Rinds are in landfills and other storage, and an estimated million pounds have been degraded. In the mid 1960's, concerns regarding the toxicity and per- tence of PCBs in the environment led to their eventual con- in the United States under the Toxic Substances Control of 1976 (TSCA). TSCA regulates the manufacturing, proc- i ng, distribution in commerce and use of PCBs (40 CFR II et seq.). Subpart G of 40 CFR 761, the PCB Spill Cleanup )|icy, specifies "how clean is clean" for spills of PCBs which :ur after the effective date of the policy (May 4, 1987). The Spill Cleanup Policy does not apply to several categories spill situations, including historic spills (those which oc- jrred prior to the policy's effective date), spills which directly mtaminate or migrate into surface waters, sewers or sewer reatment systems, private or public drinking water sources or 'istribution systems, and spills which contaminate animal graz- ig lands or vegetable gardens. For spills which fall in any of icse categories, a cleanup standard must be negotiated with lc cognizant regulatory agency(s). Determination of an ac- tptable residual concentration is imperative prior to selecting remedial technology for treatment of the specific waste tream(s). The primary basis of establishing a cleanup standard is the protection of public health and the environment. However, jhhe ability to reach a cleanup level in a given situation is also considered. Thus, current knowledge of the capabilities of remedial technologies is vital. Development of PCB treatment technologies continues due to the ubiquitous nature of the chemical. This paper discusses the current state of development o the available technologies. INCINERATION Incineration is a recognized technique of PCB destruction. TSCA requires a "six-nines" (99.9999%) destruction and re moval efficiency (DRE) of PCBs for thermal treatment sys tems. Therefore, for an incineration system to be permitted to destroy PCB containing wastes, it must be able to demonstrate conformance with this strict standard. The high temperatures and long residence times usually required to conform to this standard generally destroy all other organic components of the waste as well. - There are less than ten TSCA permitted commercial PCB incinerators currently operating in the United States. These vendors indicate that PCB destruction costs range from ap proximately $500 to $800 per ton for solid waste and $3.25 to $5.00 per gallon for liquid waste. Costs are dependent upon waste characteristics such as heating value and burn charac teristic of the waste, PCB concentration, waste matrix, and total amount of waste treated, among other factors. In some instances, it may be more economically feasible to bring a TSCA permitted incinerator to the waste, rather than transport the waste to a commercial incinerator. However, public acceptance of on-site incineration may be limited. Early regulatory agency and public involvement prior to selection of this remedial alternative may help alleviate the historical "NIMBY" (not in my backyard) attitude against thermal de struction units. Transportable incinerators are comprised of the same unit operations as permanent, commercial facilities, namely: pri mary and secondary combustion chambers, feed systems, bot . 11, No. ^^Environmental Progress (Vol. 11, No. 3) August, 1992 173 tom and fly ash handling.units, air emissions control (filters, electrostatic precipitators, wet scrubbers), heat exchangers, and exhaust stacks, Waste water treatment for cooling/scrubbing water recycle/disposal and a mobile on-site laboratory can be integral supporting operations for transportable incineration systems. Roy F. Weston, Inc., among others, operates a TSCA per mitted Transportable Incineration System (TIS) which utilizes a 23 million BTU/hr rotary kiln as the primary combustion chamber. The kiln is of standard countercurrent cylindrical design which allows retention times of fifteen to ninety min utes. Operating temperatures can be varied below 1200 to 2200F and the system can process from two to ten tons per hour of contaminated soils. It is also designed to be capable of incinerating fume, hazardous liquids and sludges at rates up to 233 mjjlion BTU/hr of heat release. A demonstration test performed in May 1988 indicated that the system could process an average of 13,650 lb/hr of soil spiked with PCB oil to an average concentration of 14,740 parts per million (ppm). The DREs achieved during this demonstration ranged from 99.99983% to 99.999990%, with residual PCB concen trations in the bottom ash of .01 ppm to .15 ppm. The feed conveyor system requires a maximum particle size of two inches, therefore, materials handling must assure this limit can be met. For loose, sandy soil, simple screening can accomplish this end. Soils with high cohesion will require an operation, such as shredding, which will break down the feed to the appropriate size. As with all incineration systems, in organic (heavy metal) constituents are not destroyed, but passed through to the ash streams. Stabilization of these streams may be required to immobilize the inorganic components to ac ceptable levels. The TSCA permit granted to the TIS eliminates the need to get additional Federal TSCA permits as the unit is moved from site to site. However, National Pollutant Discharge Elimina tion System (NPDES), Publicly Owned Treatment Works (POTW) discharge, and/or air emissions permits may still be required. Additionally, if the waste feed can also be charac terized as Resource Conservation and Recovery Act (RCRA) hazardous waste, a RCRA Treatment Storage and Disposal Facility (TSDF) pefmit must be gained. The cost of remediating PCB contaminated soils via the TIS can range from $140 to $600 per ton; and generally fall in the $180 to $200 per ton range. These costs are mainly dependent on the heating value of the waste, the concentration of PCBs to be destroyed, and the total quantity of waste to be reme diated. Ogden Environmental Services owns and operates a trans portable 10 million BTU/hr Circulating Bed Combustor (CBC). The CBC can provide DREs of 99.9999%, and is available for on-site operation. Soil feed rates vary based on soil moisture content and heating value of the waste. Solids, liquids and sludges may be treated utilizing this system, however, a max imum particle size of 1" for solid feed will determine the precombustion material preparation and handling require ments. The thermal treatment unit of the CBC consists of ceramic lined combustion loop which is comprised of a combustion chamber and cyclone. Waste is fed into the loop along with limestone, which neutralizes acid gases formed during the ther mal destruction reactions. The waste contacts hot recirculating soil from the cyclone. As it heats, it is entrained with air and travels upward through the combustor into the cyclone, where the solid fraction is separated from the combustion gases. The hot solids drop down to reenter the combustion chamber, where they will aid in heating new feed being introduced. Remediated solids remaining in the lower portion of the com bustion chamber are removed at a controlled rate by an ash conveyor system. Like the TIS, the CBC is TSCA permitted. However, air emissions, water discharge and RCRA permits must be ob tained as required. Treatment costs for remediating soili] CBC typically range from $100 to $300 per ton, depet primarily on soil moisture and quantity of material to be essed. Westinghouse Environmental Services has developed markets a Pyroplasma plasma arc process which utilh plasma torch to pyrolyze liquid organic materials at letnj atures up to 15,000C. Throughput capacities vary from to three gallons per minute in single stage units. Waste liqy are aspirated into a superheated gas stream, where the m( ular bonds of the waste are broken into their component at( These atoms recombine in the reaction chamber to form hazardous gases such as carbon monoxide, nitrogen, hydrof and some low molecular weight hydrocarbons. Acid gases l particulate carbon are removed in a wet scrubber. The result gaseous stream, primarily hydrogen and carbon monoxk drawn off and flared. The Pyroplasma unit is suitable for liquid wastes only. Uf a TSCA Research and Development Permit, it has dcr strated DREs greater than 99.9999% for PCB liquids concentrations of 70-80% PCBs by weight. This techno!' is available in mobile units. Permitting and public accept! issues for this treatment system are the same as those for TIS and CBC. A transportable Infrared Incineration System has been signed by Shirco Infrared Systems, Inc., which utilizes trically powered silicon carbide rods to provide infrared er that heats organic waste to combustion temperatures, maining combustibles are incinerated in an afterburner^ demonstration of this system in 1987 under the United Environmental Protection Agency's (EPA's) Superfund novative Technology Evaluation (SITE) program dcr strated its ability to destroy PCBs at concentrations rar from 10 ppm to 669 ppm in the feed with DREs excel 99.99%. While this demonstration did not meet TSCA'i quirement for PCB destruction by thermal treatment, tests with the same unit have achieved DREs of 99.99$ Therefore, this incineration system, based on waste spi trial burn results, may be granted TSCA approval for diation of PCB contaminated soils. IN-SITU VITRIFICATION A variation of traditional thermal treatment systems Inj In-Situ Vitrification (ISV) Technology developed by the Northwest Laboratories Division of Battelle Memorial If tute and marketed exclusively by Geosafe Corporation, is a process which melts inorganic soil for the purposi thermally destroying its organic component. This is ac plished as follows. Electrodes are placed in the soil to the desired trealt depth. A conductive starter path is placed on the surface tween electrodes, and the treatment area is covered by an gas collection hood. As a result of the electric potential belM the electrodes, current which flows through the starter | generates heat which in turn melts the underlying soils, i molten soils are generally quite.electrically conductive, all ing the process to continue to depth. The high temperali within the molten soil cause organic material (either natuf occurring or contaminants) to volatilize and pyrolyze. i resultant gases either become dissolved in the melt or mov the surface, where they combust on contact with air. Prod of pyrolization and combustion are collected in the off collection hood, and are treated prior to emission. As the soils melt, the void space is removed. A volt reduction of 20-40% is typical. When the melt mass rest an optimum, power to the electrodes is removed and the is allowed to cool naturally. As it cools, it vitrifies in) monolith which resembles naturally occurring obsidian ( 174 August, 1992 Environmental Progress (Vol. 11, N< jc glass). Th jction in vol for unrestrit [cognizant re potentially to >rated in tl of vitrified jhlity and cat ic vendor i 399% as rei |on actual wj ifyingcleam iplicable to jcrtals. ic ISV pro jfied waste n jirements ar saturated Id more cost inorganic < melt volum : generation lis technolc Ch holds wo technology |lon, but car properties, )j), unit prii She site fron STRUCTI ti several E Sivations b; quicklime hinted soils TA's Risk ' led studies, lory (RMC fy the resul led by RMC reductions achieved: d by RRI tnology A] jeted in the stripping lore, only cleavage this proce IRKMED (logical tr i Or decoi ,'C) specie lisms ma; xlcgradat opmental dies whir ?rters to i III specie} i, as we results cf C the nect tint delivt (logical t: ?4't`ssaryr ttiCietore] samples onment ating soil me glass). The surface depression which results from the m, depeiv ffiction in volume may be backfilled with dean soils, allow- ial to be j; jlbr unrestricted future use of the area upon approval by flognizant regulatory agency. evclopcd i Hentially toxic inorganic contaminants are chemically in- lich lUilU.? |brated in this matrix. Leach, hydration, and weathering ils at tcmi |of vitrified waste indicate that it has excellent long-term ary from ' flity and can expect a mean life of thousands of years, Waste llijt fie vendor indicates this process exceeds PCB DREs of ere the mo )99% as required by TSCA, but requires treatability test- ponetit ato to form n ---Jn actual waste samples to verify the process is capable of Ifying cleanup requirements. They also indicate this method en, hydroj roplicable to a variety of organic, inorganic and radioactive 'idd gase Hfrials. . The rcstill Ilje ISV process is an in-situ treatment, and the treated monoxidi tied waste may be left in place. As such, materials handling Birements are minimized. While the process can operate in esonly. Ur , saturated soils, the energy required to vaporize water t has deni tl more cost effectively be used in vitrifying soils. Organic i liquids i Inorganic debris may be left in place and treated within lis tcehnol jfhelt volume, dependent on their expected effect on off- lie aceepie peneration and residual product. those for I ffiis technology is commercially available through Geosafe, \ has been i utilizes i nfrared CIT jeratuies. I fterburnci United Si pli holds worldwide exclusive rights to it. Costs for utilizing ftechnology are on a similar order of magnitude as incinlon, but can vary greatly based on variables such as wasteproperties, volume of material, depth of required vitrifi[pn, unit price of electricity, moisture content, and distance le site from the vendor's base location in Washington. Superfuml I gram den ations ran REs excce et TSCA\ :atment, ch of 99.999, waste spe aval for r< ' INSTRUCTION USING QUICKLIME Big d several EPA remedial action sites in the recent past, ervations by regional staff had suggested that treatment [jh quicklime (CaO) may achieve destruction of PCB con ciliated soils and sludges. JmPA's Risk Reduction Engineering Laboratory (RREL) in- fled studies, both in-house and through a contracted labjtory (RMC Environmental and Analytical Laboratories) to Ijffy the results indicated in the field. The initial study con ned by RMC were extremely limited in scope, and indicated : reductions in PCB concentrations, on the order of 90%, (e achieved in the waste matrices. The in-house project de fied by RREL and conducted by their on-site contractor, jhnology Applications Inc., indicated that the reductions systems in I Iby the Pad* lemorial I poration. IL^ ae purpose Ccted in the waste matrices were due to evaporation and ini stripping in PCBs during the lime shaking process. Furpnore, only minimal amounts of products of phenyl-phenyl id cleavage were detected, further supporting the theory t this process is not applicable to the destruction of PCBs. This is acc< tOREMEDIATION ired treatm he surface :red by an ential bet' re starter /ing soils, ductive, all< 1 temperati ither naturl pyrolyze. tell or mov* a air. Prodl in the off* ion. ed. A volt t mass react ed and the vitrifies in(( obsidian (\ ^Biological treatment technologies use microorganisms to de<ify or decompose degradable organics. Naturally occurring Hive) species may be utilized or specially adapted microfganisms may be introduced into the contaminated media. ^Biodegradation of PCBs as a remedial technology is in the |velopmental stages. Many studies have identified several lerobes which exhibit an ability to degrade specific PCB Ingeners to varying degrees. These microorganisms include veral species of Achromobacter, Alcaligenes, and Pseudomas, as well as a fungus, Phanerochaete chrysosporium. it results can be obtained in biological reactors which can lure the necessary aeration, mixing, temperature control and jtrient delivery to optimize the biokinetics. ^Biological treatment systems are living systems. Survival of : necessary microbes is vital for this technology to be feasible. | Is therefore necessary to conduct treatability testing on actual iste samples to determine if the microorganisms can degrade specific PCB congeners present or even survive. While the inherent toxicity of PCBs indicates that their bio degradation would occur only at dilute concentrations, labo ratory studies performed by General Electric Company, Cor porate Research and Development have indicated degradation of soils spiked with PCBs in concentrations as high as 500 ppm Aroclor 1242. The extremely limited amount of data on field applications of biological processes to remediate PCB contaminated wastes makes it difficult to specify levels of detoxification possible in nonlaboratory conditions. Likewise, it is not possible to quan tify chemical or matrix interferences which may be encoun tered, or the costs to be expected on a per unit basis. However, bioremediation is gaining favor in hazardous waste remedia tion in both Europe and the United States. As it is utilized, more data will be made available for assessing the efficiency of the technology for a myriad of contaminants, including PCBs. Specifically, the results of a field study of biodegra dation in PCB contaminated Hudson River sediments, being conducted by General Electric, will make field application data. available for future bioremediation schemes. CHEMICAL DECHLORINATION In 1978 at the Chemistry and Biosciences Laboratory, Frank lin Research Center, a chemical reagent was synthesized and found to destroy PCBs by the process of dechlorination. Since that time, a family of alkali metal polyethylene glycolate . (APEG) reagents have been developed winch effectively dechlorinate PCBs in soils and liquids quickly. These reagents are known as KPEG or NaPEG, dependent on whether the alkali metal utilized is potassium or sodium. Research has shown that KPEG is more effective in destroying PCBs than NaPEG. In a patented process, the KPEG reagent is prepared by reacting potassium hydroxide with one of several polyethylene glycols. This reaction produces an alkoxide which reacts with one of the chlorines on the aryl ring of the PCB to produce an ether (hydroxyl substituted aryl ring) and potassium chlo ride. The substitution of the chlorine atom with the etherlinked polyethylene glycol molecule detoxifies the PCB. Ad ditional research indicated this process can also dechlorinate (and thereby detoxify) polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in either a solid or liquid matrix. This process and variations of this process have undergone numerous laboratory studies and field demonstrations. A field demonstration conducted by EPA RREL in Guam on PCB contaminated soils utilized a batch reactor equipped with a mixer and an external steam jacket to allow for process heating. The steam jacket was designed to allow it to serve as a process cooling water system as well. A vent from the reactor to a condensate collection system was also provided. Following dechlorination the treated soil was allowed to cool. Sulfuric acid was then added to adjust the pH to the ra^ge of 6 to 9. Treated wastes with unacceptable concentrations of PCBs were subsequently re-treated to provide further dechlorination. Soil was discharged from the reactor, sampled and stored pending analytical results. Over several runs, approximately 15 cubic yards of soil with an average concentration of 3,500 ppm PCBs were treated to greater than 99% reduction of PCBs. Waste soils pretreatment requirements (that is, largest par ticle size), are highly dependent on the physical configuration of the mixer employed. For the Guam demonstration, a max imum particle size of 1/2 inch was required to prevent fouling of the mixer blades against the reactor wall. Implementation of this process utilizes commercially avail able process equipment, therefore is readily available. How ever, implementation of this process may be slowed by the need to obtain TSCA, RCRA, and potentially air and water (ol. 11, No. iVironmental Progress (Vol. 11, No. 3) August, 1992 175 discharge permits. Additionally, care must be taken so as not to infringe on the patent holder's legal rights. The cost to apply this technology will vary greatly depending upon the volume of treated waste and the current reagent prices. Cost estimates for treating soil in plants with a treatment capacity of 25 tons per batch operation have been estimated to range from $242 to $347 per ton of soil, with capital-related and chemical costs accounting for approximately 84 percent of total cost. Several vendors offer dechlorination of PCB articles (trans formers with PCB oil at concentrations greater than 500 ppm) and PCB contaminated equipment (transformers filled with dielectric fluid at concentrations between 50 and 500 ppm). The systems utilized are generally flatbed trailer mounted and operate using a closed loop circulation system. This allows for reclamation of transformer oil on-site, without draining it from the transformers. For a cost premium, the operation can be performed on energized transformers, reducing downtime. Proprietary reagents are utilized to dechiorinate, dewater, degassify and desludge transformer oils. Properly utilized under the vendors' TSCA permit, these types of procedures allow for declassification of PCB and PCB contaminated electrical equipment. This in turn should reduce future liability for the electrical equipment owners, since equip ment with less than 50 ppm PCBs is less likely to release harmful quantities of PCBs to the environment. The specific nature of the proprietary reagents will determine any potential chemical and/or matrix interferences. Vendors need to be contacted for the costs of these operations. Factors which will affect the cost of treatment include type of unit to be serviced, the volume and concentration of dielectric fluid, access to equipment, and whether it will be energized or de energized. SOLVENT EXTRACTION Solvent extraction of PCBs from soils makes use of PCBs' preferential solubility in oils and various extractants over water. HARBAUER, Sanivan Group, and Resources Conservation Company (RCC) have all developed processes when PCB con taminated oily soils or sludges mixed in an extraction vessel (generally a countercurrent soil washer or mixed reactor) with the appropriate solvent. During this step, the PCBs prefer entially enter the oily solvent phase, leaving the soil phase with a greatly reduced PCB concentration. The solvent phase is decanted, and the soil phase is dried if necessary. The oily solvent fraction is then separated using standard separations techniques into oil, water, and solvent fractions. Ideally, sol vent can be regenerated or recycled for future use, and all PCBs are concentrated within the oil fraction. These processes do not destroy PCBs, but rather, concentrate them into one phase of the original waste stream with a greatly reduced vol ume as compared to the original waste. The PCBs in the con centrated stream, generally the oil fraction, must then be either thermally or chemically destroyed as required by regulation. HARBAUER and RCC have reported removal efficiencies on the order of 98 percent with oily soils contaminated with PCBs in the less than 20 ppm range during actual field scale on-site remediations. Sanivan Group will be conducting a field demonstration of their process under the auspices of EPA's SITE program on soils contaminated with PCBs in the range of 5 to 50 ppm. Feed preparation requirements for solvent extraction proc esses are determined, in part, by the physical configuration of the extraction vessel. Maximum particle size and percent fines in the soil/waste matrix will likely be a factor for soil washing techniques, since a higher ratio of fines in the waste results in a greater volume of sludge requiring final disposition. Potential chemical and matrix interferences will depend on the specific extractant and process equipment utilized. These processes have been designed for treatment of contamir freeze/tha> soils, but modifications may be possible to allow for treat! >cess, volun of liquid phase wastes as well. ^served in th Soil treatment by solvent extraction is currently com| ?r, due to u cially available. Availability of the concentrated effluent rUier studie.1 also be determined to judge overall implemenfability of Ication of th processes. As with all on-site treatment options it is re< mended that the appropriate regulatory agency(s) be not to expedite the approval/permitting process prior to in mentation. JNCLUSI Costs are very site/waste specific. A potentially slgnif portion of the overall cost of treatment is the cost for dest tion of the concentrated PCB waste stream. Vendors state i application of this technology is less expensive and more effective than incineration, but did not quote figures. Iwiien selec Stes, it is nt (cchnolog liability of ilneated in t )r example, STABILIZATION ^Icr treatme i destroy PC Chemical stabilization is a treatment process used to mobilizehazardouswasteconstituentsinasolid matrix throj; mixing the original waste stream with additives and bint (that is, cement). For treating contaminated soil and sedimc the process generally involves excavation and subsequent ations dat sidered ei |hmcaliy vi ability to moiogies version of the matrix to a solid mass which immobilizes let able contaminants. An identical process can be applied stabilize residual sludge streams with leachable contamir resulting from various other treatment methods. Stabil materials are typically sent to permitted landfills for dispt Stabilization of soils may be applied in situ by adding st mologies rfocc decon lion and de 3gies. A < lermine if t of PCBs lizing agents via a deep soil mixing auger, although effect ness may vary. Stabilization reduces the mobility! IT'. RATI contaminants, but does not destroy them. Therefore, the n of exposure to humans or the environment resulting f|< leaching contaminants at low rates over the long term exists. As with all on-site treatment technologies, a determinal) of the permits required for remediation should be sought f] i the applicable regulatory agency(s). ^ Another limitation to stabilization of wastes is the inhibllldfllp effect that organic constituents generally have on the curijjjppr process and final quality of the stabilized waste. Several Y*^ dors have developed proprietary additives which, when blemfe^ with cement, water and the contaminated soils, can overco the deleterious effect of the organic constituents in the wip* HAZCON, Inc. has performed a successful field den:' stration of immobilizing tow level (50 to 80 ppm) PCBs in s in the presence of up to 25 percent by weight of oil and gri using a cement based process with their proprietary addith* Ahmed, ehlorinal lor," Ca Hi turner, {tauced 1 Soil by . J. Etwir C'hytiow C/u'/n. I Clark, F nidation Cultures {inhaiis ol Poly Slabiliz Chloranan. Using a 10:10:1 ratio of waste:cement:ChloraR^ produced a solidified mass in which analysis of leachate cc not detect PCBs at a detection limit of 1 ug/L. A voh increase of 120 percent was observed, and cost of $250 | ton for the demonstration was calculated. International Waste Technologies (I WT) has developed (It own proprietary soil stabilization additive, HWT-20. IWTk performed a demonstration of in-situ stabilization of soils c taminated with PCBs in concentrations up to 950 ppm (** most of the samples under 300 ppm) utilizing HWT-20 ai deep soil mixing technique developed by Geo-Con, Inc. Res of this demonstration, conducted as part ofEPA RREL's SB'S program, indicate that the process may immobilize PC However, due to the low concentrations of PCBs in the trer soils (after dilution resulting from addition of cement b-L HWT-20), absolute confirmation ofthis tentative finding cc not be proven. Additionally, due to the very limited anic of volatile organics detected in the waste matrix, it is unt to predict if HWT-20 can counteract their effect on the f product. Furthermore, while unconfirmed comprest strength, permeability and wet/dry weathering tests indies the solidified mass could maintain its integrity over a t pricksoi worth P Evans,) Toxic V \ I'ouliy, * /*., 9: I pox, C. incut Tt I (leosaft ildcrati incut juunob mature Joseph, foi Org mental Kno, . fll'CB' Timber m ns t Ilk . B period of time, unsatisfactory water loss was observed dm Environmental Progress (Vol. 11, No fhonmi ivmtl I ticv* UlilfC terminal* sought Ih ic inhibit! i the cm Sevcial lien bleu m ovcKt n the \s ield dem 5CBs in \ ii and gic iry addi sit> t:Chloi.ti .ichaico . A voht of $250 .eloped tl 20. IWl of soils c 0 ppm VT-20 i nil Inc. Rcsu REL's .1 Dilize PC' n the t reft cemeni indingco ited amo , it is una on the fl compress sts indica over a 1 erved dur I. 11, No,| i freeze/thaw weathering tests. As compared to HAZCON's cess, volume increase (8.5 percent) and cost ($194 per ton) icrved in the IWT/Geo-Con process were moderate. Howr, due to uncertainties in the quality of the final product, liter studies should be conducted prior to commercial apeation of this process. Inclusions hen selecting a technology to treat PCB contaminated tes, it is necessary to take into account the applicability of technology to the specific waste stream. Availability and ibility of the technology is also of vital importance. As Heated in this paper, there are currently several technologies example, incineration, chemical dechlorination and waste er treatment technologies) which have proven their ability cstroy PCBs and for which a significant amount of apfleations data exists. There are several others which can be jdered emerging technologies--they have been proven nically viable, yet limited field applications data reduces ability to effectively judge the feasibility of utilizing these nologies to treat specific waste streams. These emerging nologies include in-situ vitrification, solvent extraction, `ace decontamination, and stabilization. Finally, biodegraon and destruction using quicklime are developmental techgies. A significant amount of study will be required to rrnine if these technologies will prove effective in destrucof PCBs. "ERATURE CITED Ahmed, M., and D. D. Focht, "Degradation of Poly chlorinated Biphenyls by Two Species of Achromobacter," Can. J. Microbiol., 19: 47-52 (1972). Brunner, W., F. H. Sutherland, and D. D. Focht, "En hanced Biodegradation of Polychlorinated Biphenyls in Soil by Analog Enrichment and Bacterial Inoculation," /. Environ. Qua!., 14: 324-328 (1985). Chynoweth, E., "New Options Take on Incineration," Chem. Week, 147: 49-50 (August 22, i990). Clark, R. R., E. S. K. Chian, and R. A. Griffin, "Deg radation of Polychlorinated Biphenyls by Mixed Microbial Cultures," Appi. Environ. Microbiol., 37:680-685 (1979). Einhaus, R. 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Mehta, "Cleanujxand Closure of a PCB Contaminated Pond," Poll. Eng., lb: 28-30(1986). Lauber, J. D., "Disposal and Destruction of Waste PCBs," PCBs and the Environment, J. S. Weid, Ed., CRC Press, Inc., Boca Raton, FL, Vol. Ill, pp. 83-151 (1987). 14. Leuser, R. M., L. A. Velazquez, A. K. Cohen, and J. Janssen, "Remediation of PCB Soil Contamination by On-Site Incineration," presented at the American Chem ical Society National Meeting (April 1989). 15. Liu, D., "Enhancement of PCBs Biodegradation by So dium Ligninsulfonate," WaterRes., 14:1467-1475(1980). 16. McDermott, J. B., R. Unterman, M. J. Brennan, R. E. Brooks, D. P. Mobley, C. C. Schwartz, and D. K. Dietrich, "Two Strategies for PCB Soil Remediation: Biodegra dation and Surfactant Extraction," Env. Prog., 8: 46-51 (1989). 17. Nielson, R., "Applications of Thermal Technologies for Decontaminating Soil," The Weston Way, Roy F. Wes ton, Inc., Product Literature (1989). 18. Resources Conservation Company, "Hazardous Waste Cleanup, The B.E.S.T. Solution from Resources Conser vation Company," Product Literature, 1988. 19. RMC Environmental & Analytical Laboratories, Interim Report on the Disappearing PCBs Project (1991). 20. Savage, P., "Cleaning Up PCBs On-Site," Chem. Week, 140: 13-14 (1987). 21. Sawyer, S., and M. K. Stinson, "In-Situ Stabilization/ Solidification of PCB-Contaminated Soil," EPA/600/D- 89/119 (1989). 22. Snider, E. H., "PCBs and DEHPs in Wastewater," Poll. Eng., 19: 48-49 (1987). 23. Sonnen, Dr. H. D., W. Groschel, and M. Nels, "Expe rience with the HARBAUER PB3 Soil Cleaning System," Presented at USEPA Forum on Innovative Hazardous Waste Treatment Technologies: Domestic and Interna tional (1989). 24. Soundararajan, Dr. R., Final Report on the "Disappear ing PCBs" Project, RMC Environmental Analytic Lab oratories (1991). 25. Stinson, M. K., "EPA SITE Demonstration of the Inter national Waste Technologies/Geo-Con In-Situ Stabiliza tion/Solidification Process," J. Air Waste Manage. Assoc., 40: 1569-1576 (1990). 26. Sudell, G. W., Project Summary Evaluation of the B.E.S.T. Solvent Extraction Sludge Treatment Technol ogy Twenty-Four Hour Test, EPA/600/S2-88/051 (1988). 27. Sunohio Company, PCBX Product Literature (1985). 28. Taylor, M. L,, J. A. Wentz, M. A. Dosani, W. Gallagher, and J. S. Greber, Project Summary Treating Chlorinated Wastes with the KPEG Process, EPA/600/S2-90/005 (1990). 29. U.S. EPA SITE Technology Demonstration Summary, Technology Evaluation Report, SITE Program Demon stration Test, HAZCON Solidification, Douglassville, Pennsylvania, EPA/540/S5-89/001 (1989). 30. U.S. EPA SITE Technology Demonstration Summary, Technology Evaluation Report, Shirco Pilot-Scale In frared Incineration System at the Rose Township Demode Road Superfund Site, EPA/540/S5-89/007 (1989). 31. U.S. EPA SITE Fact Sheet, Proposed demonstration of the Sanivan Group Extraksol Solvent Extraction Tech nology, Pinette's Salvage Yard Superfund Sit^, Washburn, Maine (1991). 32. Wilbourn, R. G., and B. M. Anderson, "Contaminated Soil Remediation by Circulating Bed Combustion," Presented at U.S. EPA Forum on Innovative Hazardous Waste Treatment Technologies: Domestic and International (1989). 33. Woodyard, J. P., and J. J. King, "Recent Technology Developments for PCB Destruction and Oil Recycling," Presented at DOE Oak Ridge Model Conference (1987). 34'. Woodyard, J. P., and E. M. Zoratto, "State-of-the-Art / Technology for PCB Decontamination of Concrete," Pre. sented at IEEE Conference on PCBs and Replacement \ Fluid (Motech '86) (1986). / ivironmenta! Progress (Vol. 11, No. 3) August, 1992 177