Biodegradation of lower chlorinated benzenes(tri-,di-and monochlorobenzene)was assessed at a coastal aquifer contaminated with multiple chlorinated aromatic hydro-carbons.Field-derived microcosms,established with groundwater from the source zone and amended with a mixture of lower chlorinated benzenes,evidenced biodegradation of monochlorobenzene(MCB)and 1,4-dichlorobenzene(1,4-DCB)in aerobic microcosms,whereas the addition of lactate in anaerobic microcosms did not enhance anaerobic reduc-tive dechlorination.Aerobic microcosms established with groundwater from the plume con-sumed several doses of MCB and concomitantly degraded the three isomers of dichloroben-zene with no observable inhibitory effect.In the light of these results,we assessed the ap-plicability of compound stable isotope analysis to monitor a potential aerobic remediation treatment of MCB and 1,4-DCB in this site.The carbon isotopic fractionation factors(ε)ob-tained from field-derived microcosms were-0.7‰±0.1 ‰ and-1.0‰±0.2 ‰ for MCB and 1,4-DCB,respectively.For 1,4-DCB,the carbon isotope fractionation during aerobic biodegra-dation was reported for the first time.The weak carbon isotope fractionation values for the aerobic pathway would only allow tracing of in situ degradation in aquifer parts with high extent of biodegradation.However,based on the carbon isotope effects measured in this and previous studies,relatively high carbon isotope shifts(i.e.,△δ13C＞4.0 ‰)of MCB or 1,4-DCB in contaminated groundwater would suggest that their biodegradation is controlled by anaerobic reductive dechlorination.

Alba Trueba-Santiso;Jordi Palau;Jesica M.Soder-Walz;Teresa Vicent;Ernest Marco-Urrea

Department of Chemical,Biological and Environmental Engineering,Universitat Autònoma de Barcelona(UAB),08193 Bellaterra,Spain;MAiMA group,SGR Applied Mineralogy,Geochemistry and Geomicrobiology,Department of Mineralogy,Petrology and Applied Geology,Faculty of Earth Sciences,Universitat de Barcelona(UB),Marti Franques s/n,08028 Barcelona,Spain

环境科学学报（英文版）

[1]Alba Trueba-Santiso;Jordi Palau;Jesica M.Soder-Walz;Teresa Vicent;Ernest Marco-Urrea-.Assessment of aerobic biodegradation of lower-chlorinated benzenes in contaminated groundwater using field-derived microcosms and compound-specific carbon isotope fractionation)[J].环境科学学报（英文版）,2022(08):204-213

microcosms,Biodegradation,monochlorobenzene,dichlorobenzene,dichloroben,zene,plicability,biodegra

Assessment,biodegradation,lower,chlorinated,benzenes,contaminated,groundwater,using,field,derived,compound,specific,isotope,fractionation,tri,was,assessed,coastal,aquifer,multiple,aromatic,hydro,carbons,Field,established,from,source,zone,amended,mixture,evidenced,MCB,DCB,whereas,addition,lactate,anaerobic,did,not,enhance,dechlorination,Aerobic,plume,sumed,several,doses,concomitantly,degraded,three,isomers,observable,inhibitory,In,light,these,results,ap,stable,analysis,monitor,potential,remediation,treatment,this,site,isotopic,factors,tained,were,respectively,For,during,reported,first,weak,values,pathway,would,only,allow,tracing,situ,parts,high,extent,However,effects,measured,previous,studies,relatively,shifts,13C,suggest,that,their,controlled,by,reductive

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