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[doc] XANES analysis of the mechanisms of arsenic removal in biological iron and manganese treatment unit

By Gerald Sims,2014-09-08 14:49
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[doc] XANES analysis of the mechanisms of arsenic removal in biological iron and manganese treatment unit

    XANES analysis of the mechanisms of

    arsenic removal in biological iron and

    manganese treatment unit

Vo1.25(Supp1.)2006CHINESEJ0URNALOFGEOCHEMISTRY

    ;Microwaveremediationofoilcontaminatedsoils

    ;HuiSHANGSamuelW.Kingman,ColinE.Snape,JohnP.Robinson

    ;SchoolofChemical,EnvironmentalandMiningEngineering,UniversityofNottingham,UniversityPark,Nottingham,UK

    ;113

    ;Thecontaminationofsoilhasbeentheresultofcommercia1.industrialandmilitaryactivities.Amongthevarietyoftheavailable

    ;technologiesoforganiccontaminatedsoils.thermalmethodsensurethegreatestefficiencyoftheabove99%.Therrnaltechnologies

    ;distinguishthemthroughaveryshortremediationtimeandapossibilitytotreatawiderangeofcontaminantsascomparedtoother

    ;treatmenttechniquessuchasbioremediationorsolventextraction.Microwaveheatingtechniquediffersfromconventionalheating

    ;andhasthesignificantadvantageofgreatertimeandenergysaving,selectiveanduniformheating,aswellascleanheating,ithas

    ;beenshowntobeapotentiallyimportanttechniqueforachievingtherequirede

nvironmentaldischargelimit.ItwasfcIundthatthe

    ;microwavereceptorswithinthematerialmatrix(suchaswater)absorbedthebulkoftheappliedmicrowaveene.Thisenergy

    ;subsequentlybeingtransferredtotheoilintheforrnofheat.thiswasshowntocausetherrnaldesorption.Resultssuggestthat

    ;maximumheatingratesorpowerlossdensitiescouldbeachievedifthesamplem~erialhadahighdielectriclossfactorandwas

    ;placedinthepositionofmaximumelectricfieldstrength.andthetreatmentefficiencycanreachashighas84%.Thecostsof

    ;microwavetreatmentareshowntobeaslowasonetenthofconventionalmethods.whichmakesitanattractivemethodforscaleup

    ;andeventualindustrialimplementation.

    ;Keywordsmicrowaveheating;remediation;oilcontaminatedsoil;dielect

    richeating

    ;XANESanalysisofthemechanismsofarsenicremovalinbiologicalironandmanganese

    ;treatmentunit

    ;YokoFujikawa,DaisukeYoneda,AtushiMinami,HiroshiYashima,ToshioTonokai,Sotoji

    ;Tani,MasamiFukui,TatuhideHamasaki,MasatakaSugahara

    ;ResearchReactorInstitute,KyotoUniversity,Osaka,Japan ;OsakaSangyoUniversity,Osaka,Japan

;GroundwaterResourcesDevelopmentCenter,Osaka,Japan

    ;royorosuikiCo,Dto,Japan

    ;Biologicalironandmanganeseremovalutilizingindigenousironandmanganeseoxidizingbacteria(IIhereafter)ingroundwater

    ;canalsobeappliedtoarsenicremovalaccordingtoourpilotscaletest.Thear

    senicremovalprobablyoccurredthroughsorptionand

    ;complexationofarsenictoironandmanganeseoxidesformedbyenzymicactionofIRB.Weinvestigatedthechemicalpropertiesof

    ;ironandmanganeseoxidesinIRBfloeandthevalencestateofarsenicsorbedtothefloetoclarifythemechanismsofthearsenic

    ;[especiallyAs(III)

    remova1.ThefloesampleswerecollectedfromtwodrinkingwaterplantsusingII(JyoyoandYam~okoriyama,

    ;Japan),andourpilotscaletestsitewherearsenicandironremovalusingIIisunderway(Mukoh,Japan).TheJyoyoand

    ;Yam~okoriyamaIRBfloesamplesweresubjectedtoAs(III1andAs(V1sorptionexperiments.Theelementalcompositionofthefloe

    ;sampleswasmeasured.XANESspectrawerecollectedonAs,FeandMnK

    edgesatsynchrotronradiationfacilitySpring8(Hyogo,

    ;Japan).FT-IRandtheXraydiffractionspectraofthesampleswerealsoobtained.TheIRBfloecontainedca.35Fe.0.3%3.5%

    ;Mnand2%6%PThesampleswerehighlyamorphousandcontainedferrihi

dritesandhydratedironphosphate.Accordingto

    ;XANESanalysesofIRB,AsassociatedwithIRBwasin+5valencestatewhenAs(III)(orAs(V))wasaddedinlaboratorysorption

    ;test.Fein+3valencestate.andMnamixture0f+3and+4valencestates.SmallshiftwasobservedintheXANESspectraofIRBon

    ;AsKedgeastheequilibrationtimeofthesorptionexperimentwasincreased.GradualoxidationofasmallamountofAs(?1

    ;associatedwithIRBorchangeinarsenicbindingwithsorptionsiteweretheprobablemechanism.As(III1wassorbedtosynthesized

    ;bimessiteandmanganesedioxideasAs(V1underabioticcondition.As(III1wasalsoSOrbedtosynthesizedaFeOOH,7-FeOOH,

    ;andhydratedironphosphateefficiently,probablyasAs(V).ApparentlyAs(III)wasoxidizedtoAs(V)whensorbedtoIIfloe

    ;andsomesynthesizedminerals.Eitherdirectbiologicaloxidationbyironbacteriaand/orabioticoxidationbymineralsproducedby

    ;thebacteriamusthavecausedsuchoxidation.Therelativeimportanceofbiologicaloxidationandabioticoxidationisnow

    ;investigated.

    ;Keywordsarsenic;groundwater;XANES;ironandmanganeseoxidizingbacteria;removal

    ;

    ;

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