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�e Bioremediation
<br /> r continued from page 25 cal detection. In essence, the leachable
<br /> diation to clean up a site to background fraction is treated almost to zero.
<br /> 9.-
<br /> 't u � levels. This myth is partially true and However, for the same soil matrix,
<br /> fl0 ♦ partially false. Bioremediation will treat only 60 percent to 90 percent of the total
<br /> }
<br /> /� almost all of the contaminants that are contamination is treated by biore-
<br /> Do� "to- available to the microorganisms. How- mediation. The balance is bound in the
<br /> blelriS ever, much of the contamination at soil and may pose no risk to human
<br /> many sites is not available to microor- health or the environment.
<br /> ganisms. For the contamination to Bioremediation of hazardous chemi-
<br /> become available to the microorganisms, cals has progressed a long way from its
<br /> it must leach from the soil and become commercialization in the mid-198(
<br /> soluble in water. Different soils have There have been numerous success sto-
<br /> different leaching characteristics.' Each ries associated with the technology.
<br /> t chemical has different solubility More than $250 million have been saved
<br /> t r r r r characteristics and therefore will leach by the application of the technology to a
<br /> r in a different manner. few remediation projects.The technology
<br /> To understand what portion of con- now has matured to the point that it can
<br /> taminatinn can he trratrx} by bioreme- he applied with certainty, providing
<br /> diction, it is important to understand proper site screening and treatability
<br /> + how treatment success has been deter- work is conducted. Q
<br /> mined historically. Regulatory agencies
<br /> typically have utilized gross con- References
<br /> taminant indicators such as oil and
<br /> ,
<br /> . ., grease and total petroleum hydrocar- 1. Block, R., Kabrick, R„Stroo, if.Swett,
<br /> bons to estaLlish cleanup objectives.
<br /> t:.,"itiorcntediation of Pelrolcrnn (_ontami-
<br /> ' ', t
<br /> nated Soils — Why Doesn't It Work Sorne-
<br /> These historic regulatory approaches times?" Presented at American Institute of
<br /> to bioremediation were flawed. The use Chemical F"ngineen 1992 Spring Meeting,
<br /> w.I ,. of total petroleum hydrocarbons suffers RE;TEC, Febrvary 1992,Tucson,Ariz.
<br /> from analytical problems. A unkc'rsully '. Itnrbaker, Gaylen, "Screening Criteria
<br /> applied analytical method for measuring
<br /> for In Situ Bioreclamation of Contaminated
<br /> Ayrsirers," summarized in The Ilazardous
<br /> ll r r r r total petroleurn hydrocarbons is not ttJsrc Consultant, pp. 1-4, July-Anguli, �!
<br /> ' available. 1989, Denver,Colo. r
<br /> ,etermined depth or pull,series aMore importantly, gross indicators of 3•Devine,Katherine,et.a1.,"Itioremcdia-
<br /> ' + ' fora' on Case Study Collection: 1991 Auginenta-
<br /> composite sample.
<br /> contamination, Such as total petroleum lion
<br /> of the Alternative Treatment "1'cchnol-
<br /> hvdrocarbons :inti nil and grease, have _ -Info nrration Center (.1FHQ,New '• U.S.
<br /> Dual r Illiquid Sr no relationship to the risks posed to Environmental Protection Agency 13ioremc-
<br /> ' human health and the environment. A diction Action Committee Data Identireca.
<br /> ecover' orground water wells to check, i total petroleum hydrocarbon mixture tion/Collection Subcommittee, February
<br /> forcontaminants heavier than water. 1992,Washington,D.C.
<br /> Including hydrmrbons.' made up of 90 percent benzene is treated 4. Lantz, Robert M, "Evaluating the
<br /> the same way as a material that has 90 Feasibility of In Situ Bioremediation," sum-
<br /> s percent decane.The environmental risks nrarized in The Ifazrrdous I. asre Consult-
<br /> of these two materials are quite differ- ant, pp. 1.16-1-20, January-February 1992,
<br /> SoflCdahploftbes/ Denver,Colo.
<br /> ,r
<br /> 1 t r t r t r t. ant. ;. Linz, D.G., Middleton, A.C., Nakles,
<br /> Monitor underground stoiraThe total constituent analysis tech- D.V. "The influence of Soil Composition on
<br /> ` underground ' ' pique also does not reflect the phenom- Bioremediation of PAH-contaminated
<br /> ' ena of contaminant leaching or bio- Soils,"in Remediation,Fall 1991,New York,
<br /> Pre-site Investigatloris for soil gas or for availability. Research has demonstrated N.Y.
<br /> tracking vapor 6. Office of Solid Waste and Emergency
<br /> that while a compound may exist in a Response,"Innovative Treatment Technolo-
<br /> soil matrix, it is not always available to gies: Semi-Annual Status Report," U.S.
<br /> Weir rlize the environment. Different soils and Environmental Protection Agency, Septem-
<br /> design applications ' meet organic matter in soils bind contami- ber 1991,Washington,D.C.
<br /> ' ' ' nants so that they are not available to y Office o[ Solid waste and Emergency
<br /> Response and Office of Research and Devei-
<br /> microorganisms, humans or the envi- opment, U.S. Environmental Protection
<br /> A%eVr ronment in general. Agency, "Bioremediation in the Field,"
<br /> Fortunately, EPA has developed a EPV54012-911018, No-3, August 199I, Cen-
<br /> - A
<br /> — eta method to determine the availability of a ter for Environmental Research Information,
<br /> contaminant to the environment Cincinnati, Ohio 45268-
<br /> Ne through the toxicity characteristic leach-
<br /> Supplying procedure (TCLP). Data indicate t
<br /> ' ' Geoffrey 1f.5wea it senior program manager in the rucson,
<br /> AineriCan Falls, ID 83211that bioremediation can treat many A>iz office of ReTre, Remediadon Technologies Inc. He
<br /> leachable biodegradable organics to or sprdalizes in the evaluation and ronfrol of err, wafer and
<br /> 1-800-635-7330 very close to the current levels of analyti- hazardous waste emissions from industrial operations.
<br /> Circle 18 on card.
<br /> 26 ENViRONIMENTAL PROTECTION
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