ReduceuncertaintyinbioremediationofPetrolumehydroc

11..IINNTTRROODDUUCCTTIIOONNGlobally,petroleumhydrocarbonsareawidelyutilisedresource,buttheirusehasresultedincontaminationthroughaccidentalspillageandleakage(Pollardetal.,1994).Certaincomponentsofpetroleumcontaminationmayposeriskstohumanhealth,property,watercourses,ecosystems,andotherenvironmentalreceptors(Nathanailetal.,2007).Thereareaplethoraofapproachesto,andtechniquesavailablefor,theremediationofcontaminatedland(Biowise,2000;Whittakeretal.,1995;Wood,1997).One’schoiceofapproachdependsonanumberofenvironmental,economicandhumanhealthconsiderationsamongothers(EnvironmentAgency,2005).Inthecontextofthisresearch,biopilingandwindrowturningofimpactedsoilareimportantengineeredsystemsthatallowexsitubutoftenon-siteremediationofhydrocarbonimpactedsoils(Figure1).Whileon-site/exsituremediationisrecognisedasacosteffectivetechnologyanditsapplicationisincreasing,itsperformancecontinuestoberepresentedbyreferencetoreductionsinthehydrocarbon‘load’insoilsbeingtreated,ratherthanreductionsintherisksposedbyhydrocarboncontamination.Riskassessmentisawell-establishedandimportanttoolforenvironmentalmanagementdecisions,whichiscommonlyusedinpetroleumhydrocarboncontaminatedlandmanagement(Brassingtonetal.,2007).Itisemployedasameansofassessingandmanagingpotentialimpactstohumanandecosystemhealth(Vegteretal.,2002).Severalrisk-basedframeworksforpetroleumhydrocarbonsinsoilhavebeenpublishedundertheauspicesoftheAmericanSocietyforTestingandMaterials(ASTM,1994),TotalPetroleumHydrocarbonCriteriaWorkingGroup(TPHCWG,1999),theCanadianCouncilofMinistersoftheEnvironment(CCME,2000),theAmericanPetroleumInstitute(API,2001),theMassachusettsDepartmentofEnvironmentalProtection(MaDEP,2002)andtheEnvironmentAgencyofEnglandandWales(EnvironmentAgency,2005),eachreflectingnationallegislation,arangeofexpertjudgementsandsocioeconomicissues(Wangetal.,1998;Viketal.,2001).Typicallytheseframeworksadoptathreetieredapproachwithincreasinglysophisticatedlevelsofdatacollectionandanalysis,asanassessormovesthroughthetiers.However,theseframeworksarenotalwayssupportedbysuitableandrobustanalyticalprotocols,especiallyinthecaseofmatricescontaminatedwithweatheredhydrocarbons.Thecompositionofpetroleumhydrocarbonproductscanvarysubstantiallydependingonthenature,composition,anddegreeofprocessingofthesourcematerial.Oncereleasedtotheenvironment,petroleumproductsaresubjecttophysical,chemicalandbiologicalprocesses(weathering)thatfurtherchangetheircomposition,toxicity,availabilityanddistribution(partitioning)withintheenvironment(Figure2).Theextentofweatheringexperiencedisparticularlyimportantwhencharacterisingpetroleumcontaminationpriortoremediationandlandmanagementassessment.Also,acomparisonofreferenceanalyticalmethodsusedforpetroleumriskassessmentprotocols(Brassingtonetal.,2007)highlightstheneedforpracticalandsimpleextractionproceduresthatallowabettercharacterisationofbothaliphaticandaromatichydrocarbonfractionswithinoil-contaminatedsamples,includingsoilandsedimentsampleswithhighmoisturelevels.InaUKcontext,thedevelopmentofnovelmethodsshouldalsoallowtheidentificationofrisk-indicatorcompoundswithineachhydrocarbonfraction,andthemonitoringofrecalcitrantbiomarkerstoenableverificationoftreatmentsuccess.Historically,inadequatecharacterisationandverificationhascontributedtoalackofinvestorand,onoccasion,regulatoryconfidenceintechnology,creatingabarriertosecuringanestablishedmarket(CIEF,2002).Specifically,theUrbanTaskForce(1999)consideredUKbrownfieldinvestmenttobeheldbackbylowconfidenceinremedialtechnology,inconsistenttechnicaladviceandtheabsenceofpublicisedsuccesses.Acriticismofriskassessmentmaybethatitmakesuseofmodelleddataandassuchcouldbeinherentlyconservativeinadoption.Toaddressthis,inadditiontoriskassessmentprocedures,theteamdevelopedandappliedasuiteofecotoxicityassaystoassesshazardandthechangesinhazardassociatedwithtreatment.Whilethesemaybemorereflectiveofecologicalassessment,theirsensitivityandrapidresponsemakethemsuitableformonitoringchangesassociatedwiththetreatmentsapplied(Figure3).Thisresearchproject,LINKBioremediationBIOREM35andCL:AIREResearchProjectRP18offeredanopportunitytointegratebiological,chemicalandecotoxicologicaldiagnostics,hazardandriskassessmentandthetransferoflaboratoryfindingstothefieldscale(Figure3).Mostimportantlythestepsenhancedconfidenceandcertaintyontheadoptionoftechniquestomeetriskderivedcriteria.BBiioorreemmeeddiiaattiioonnooffhheeaavvyyhhyyddrrooccaarrbboonnss--rreedduucciinngguunncceerrttaaiinnttyyiinnmmeeeettiinnggrriisskk--bbaasseeddttaarrggeettss::llaabboorraattoorryyttooffiieellddssccaallee((PPRROOMMIISSEEPPrroojjeecctt))RRBB1100((JJaannuuaarryy22001100))CCLL:AIRECopyright©CL:AIRE(ContaminatedLand:ApplicationsinRealEnvironments).CL:AIREresearchbulletinsdescribespecific,practicalaspectsofresearchwhichhavedirectapplicationtothecharacterisation,monitoringorremediationofcontaminatedsoilorgroundwater.Thisbulletindescribesweatheredhydrocarbontransformationanditsimplicationsforbioremediation,analysisandriskassessment(outputsfromLINKBioremediationProject-BIOREM35).resea