66Arsenicmobilityfromanthropogenicimpoundmentsedim

Arsenicmobilityfromanthropogenicimpoundmentsediments–Consequencesofcontaminationtobiota,waterandsediments,Poša,EasternSlovakiaEdgarHillera,L’ubomírJurkovicˇa,JozefKordíkb,*,IgorSlaninkab,MichalJankulára,JurajMajzlanc,JörgGöttlicherd,RalphSteiningerdaComeniusUniversityinBratislava,FacultyofNaturalSciences,DepartmentofGeochemistry,MlynskaDolina,84215Bratislava,SlovakRepublicbGeologicalSurveyofSlovakRepublic,DepartmentofEnvironmentalGeochemistry,Mlynskadolina1,81704Bratislava,SlovakRepubliccInstituteofMineralogyandGeochemistry,Albert-Ludwig-UniversityofFreiburg,Albertstrasse23b,D-79104Freiburg,GermanydInstituteforSynchrotronRadiation,ForschungszentrumKarlsruheGmbH,Hermann-von-Helmholtz-Platz1,76344Eggenstein-Leopoldshafen,GermanyarticleinfoArticlehistory:Received8December2008Accepted15September2009Availableonline19September2009EditorialhandlingbyR.B.WantyabstractAnimpoundmentlocatednearthevillageofPoša,Slovakia,isasignificantsourceofcontaminationwithAsoriginatingfromthedepositedcoalfly-ashe.WaterspenetratingtheimpoundmentareenrichedinAsandotherpotentiallytoxicelements.Asaconsequenceofthecontamination,theKyjovBrookandtheOndavaRiverhavebeenextensivelypolluted.Themobilityandsolid-statepartitioningofAsintheimpoundmentmaterialandstreamsedimentswereinvestigatedusingcolumnleachingandbatchextrac-tiontests,andafive-stepsequentialextractionprocedure.Moreover,toinvestigatethebioavailabilityofAs,twonativeplantspecies(Typhalatifolia,orcattail,andPhragmitesaustralis,orcommonreed)growingatthesitewerecollectedandanalyzed.TheAsconcentrationsinrepresentativesedimentandwatersam-plesrangedfrom36.3to3210mg/kgandfrom4.05to613lg/L,respectively,bothbeingmanytimesabovethebackgroundlevels.AlthoughapartofAswaspresentinareadilysolubleform(6.6%),themajorityofAswasmainlyassociatedwithFeandMnoxides(37%)andresidualphases(51%).Combinedresultsofthecolumnleaching,batchextraction,andsequentialextractiontests,aswellasmineralogicalanalysis,indicatedthatAsmobilisationpotentialfromthesedimentsislikelycontrolledbyFe,AlandMnoxides,andbypH.Therewasnoinfluenceofvariousanions(PO34;SO24,NO3;ClandHCO3)onAsmobilitywhenpresentinaqueoussolutionatconcentrationsanalogoustothoseinthewateroftheKyjovBrook.PlantsgrowingintheimpoundmenthadAsconcentrations10–100timesgreaterthandidthesameplantsgrowinginarelativelynon-pollutedarea.2009ElsevierLtd.Allrightsreserved.1.IntroductionArsenicisanelementofgreatconcerninterrestrialandaquaticenvironmentsbecauseofthehightoxicityofcertainspecies(JainandAli,2000;Reimannetal.,2009).ThenaturaloccurrenceofAsinaquaticenvironmentsisusuallyassociatedwithsedimentaryrocks,weatheredvolcanicrocks,geothermalareas,andfossilfuels.MostoftheAsderivedfromanthropogenicsourcesisreleasedasaby-productofmining,metalrefiningprocesses,burningoffossilfuels,andagriculturalpractices(SmedleyandKinniburgh,2002).MiningandindustrialactivitiesinvolvingcoalburninghavealsoproducednumeroussitesinSlovakiawithelevatedAsconcentra-tionsinsurfacewaters,soils,streamsediments,andimpoundmentmaterials(BodišandRapant,1999;Jurkovicˇetal.,2006;Lintnerováetal.,2006).Arsenicspeciesaccumulatedinsoilsandstreamsedimentscan-notbeconsideredtobetotallyisolatedfromgeochemicalcycles,butmayberemobilisedbackintosolutiondependingonthestrengthofsolid–Asinteractionsandgeochemicalconditions(GohandLim,2005).Arsenicinstreamsedimentspartitionsintodifferentchemicalformsassociatedwithvariousorganicandinor-ganiccomponents,dependingonphysico-chemicalandgeologicalconditions(Galánetal.,2003;Fritzscheetal.,2006).Determina-tionofthetotalcontentofAsinsoilsandsedimentsprovideslim-itedinformationaboutitsmobilityandbioavailabilitysincethetoxiceffectsandthegeochemicalpathwaysofthiselementaredeterminedmainlybythemobileforms(Quevauvilleretal.,1993;Birdetal.,2003;Romeroetal.,2003).Environmentalriskassessmentsbasedsolelyonthemeasurementsofthetotalcon-tentsofpotentiallyharmfulmetalsandmetalloidsfailtotakeintoconsiderationthemobilityandbioavailabilityofthedifferentforms.Therefore,variousleachingtestsareusedtoevaluatemobileandbioavailablefractionsofthesemetalsandmetalloidsinsoilsandsediments(Caietal.,2002;Sahuquilloetal.,2003;FayigaandMa,2005).Tostudythesolid-statepartitioningofmetalsandmetalloidsbetter,differentsequentialextractionprocedureshavebeendevelopedandused(Tessieretal.,1979;Ureetal.,1993;0883-2927/$-seefrontmatter2009ElsevierLtd.Allrightsreserved.doi:10.1016/j.apgeochem.2009.09.021*Correspondingauthor.Tel.:[phone];fax:[phone].E-mailaddress:[e-mail](J.Kordík).AppliedGeochemistry24(2009)2175–2185ContentslistsavailableatScienceDirectAppliedGeochemistryjournalhomepage:äisänen,2009).Mea-surementsintheseproceduresarebasedonthermodynamicequi-librium,andhencethemobilityrateofmetal/metalloidisnotconsidered.Becauseofthedynamiccharacteristicsofthewater–sedimentsystems,kineticspeciationstudiesareausefulapproachforcomparisonofactualleachabilityormobilityofpotentiallytoxicelements(Sukreeyapongseetal.,2002;Gismeraetal.,200