PerformanceoftheConstructedWetlandSystemforthe

Braz.arch.biol.technol.v.51n.6:pp.1279-1286,Nov/Dec20081279Vol.51,n.6:pp.1279-1286,November-December2008ISSN1516-8913PrintedinBrazilBRAZILIANARCHIVESOFBIOLOGYANDTECHNOLOGYANINTERNATIONALJOURNALPerformanceoftheConstructedWetlandSystemfortheTreatmentofWaterfromtheCorumbataíRiverAnaKleiberPessoaBorges1,SâmiaMariaTauk-Tornisielo1*,RobertoNavesDomingos1andDejaniradeFranceschideAngelis21CentrodeEstudosAmbientais;UniversidadeEstadualPaulista;Av.24A,1515;[e-mail];13506-900;RioClaro-SP-Brasil.2DepartamentodeBioquímicaeMicrobiologia;InstitutodeBiociências;UniversidadeEstadualPaulista;[e-mail];13506-900;RioClaro-SP-BrasilABSTRACTTheaimofthisworkwastostudytheconstructedwetlandsystemforthetreatmentofwaterfromtheCorumbataíriversimulatedonalaboratoryscale.Theparametersanalyzedatdifferentpointsofthesystemwereammonia,biochemicaldemandforoxygen(BDO),chemicaldemandforoxygen(CDO),chlorides,apparentcolor,conductivity,dissolvedoxygen,magnesium(Mg),sodium(Na),potassium(K),silicon(Si),totalphosphorous,totalcoliformsandEscherichiacoli,totaldissolvedsolids(TDS),turbidity,andmacrophytebiomass.Theresultsdemonstratedthatthisalternativewatertreatmentsystemwaseffectiveinremovingthemicroorganisms(totalcoliformsandE.coli),amongotherparametersanalyzed,forvaryingperiodsofthetreatment,promotingnotableimprovementinthequalityofthewatertreatedfromtheCorumbataíRiver.KeyWords:Aquaticmacrophytes,filteringsoil,microfiltration,bioreactor,microorganisms*AuthorforcorrespondenceINTRODUCTIONWaterhasbecomeincreasinglyscarceduetothelackofurbanplanning,rapidincreaseinthepollution,waste,andthelackofwaterre-usageandeffectiveenvironmentaleducationprograms.WateruseregulationwasproposedasanusefultoolinbeginningdiscussionofwaterqualitygoalsaccordingclassificationsystemproposedbytheCONAMAresolution(SouzaandTundisi,2003).Thehighcostofimplementingthebasicsanitationprojectscanleadtohigherpublicdebtandcompetefortheresourcesthatarebadlyneededforotheressentialservices,suchasthehealthandeducation(Rebouçasetal.,1999).Theeffortstodeveloptheprojectsthatarebothlowcostandeffectivehave,paradoxically,beenmoreintensiveinthewealthiercountriesofEuropeandtheUnitedStates,since1970.Someproposalsfortheeffluentandwatertreatmentexistinliterature,amongstthese,oftheuseofultrasoundforthereductionofthenumberofthebacteria(Domingosetal.,2005).Analternativeprocessfortreatingthewater,effluents,anddomesticsewageistheCWs(constructedwetlandsystem)(Salatietal.,1999).Despiteevidenceofthetoxiceffectsontheaquaticplantswhentheeffluenthasahighorganicload(HaynesandGoh,1978;Gersbergetal.,1986),theseCWshavebeenusedasthesecondaryandtertiarytreatments(Greenetal.,1996;StoberetBorges,A.K.P.etal.Braz.arch.biol.technol.v.51n.6:pp.1279-1286,Nov/Dec20081280al.,1997;Nerallaetal.,1998;Billoreetal.,1999),andcanbeusedfortheprimarytreatmentofthewateroreffluentsasanalternativetothetraditionalprocesscurrentlyinuse.Furtadoetal.,2002investigatedthemethanogenicactivityinsedimentoftheImboacica(humanimpacted),CabiúnasandCompridacoastallagoonsinRiodeJaneiroState(Brazil).TheuseofCWstotreattheriverwaterandresidualwaterhasbeenstudiedinanumberofcountries(Hammer,1989;CooperandFindlater,1990;OlsonandMarshall,1992;Moshiri,1993;KadlecandKnight,1996),andtheproblemsassociatedwithithavealsobeenstudied(Pantetal.,2001;GómezCerezoetal.,2001;Braskerud,2002a,b;Söderqvist,2002;PantandReddy,2003).TheuseoftheaquaticmacrophytesintheCWshasbeenprovenforreducingtheamountoftheorganicmatter(Brix,1993;Nguyen,2000),removethenutrients(Mitschetal.,2000),andreducethepathogens(PerkinsandHunter,2000).InBrazil,thistreatmenthasbeenquestionedwithrespecttoitsefficiencyandcost/benefit;nevertheless,basedonthestudiesbyCarmenLúciaRoquettePinto,oftheUniversidadeFederalFluminense,andfindingspresentedatthe6thInternationalConferenceontheWetlandSystemsforWaterPollutionControl,inÁguasdeSãoPedro,SãoPaulo(SP),1998,ithasgraduallybecomeasubjectofstudy.Inthisstudy,wesoughttoverify,onalaboratoryscale,theefficiencyofdescendingflowCWscontainingparticulates,microorganisms,macroorganisms,peat,andinertindustrialresidues,forthetreatmentofwaterfromtheCorumbataíRiverinRioClaro,SP.MATERIALSANDMETHODSThecollectionsiteforthewatersamplesfromtheCorumbataíRiverwasinthedistrictofAssistência,inthemunicipalityofRioClaro,SP,UTMcoordinatesX230064andY7507759.OnethousandfivehundredlitersofwaterwerecollectedforuseintheCWsystem,withphysical-chemicalproperties(Palma-SilvaandTauk-Tornisielo,2001)thatplacedtheminclass4,accordingtoCONAMAResolution357/2005(CONAMA,2005).TheCWswasconstructedin250LPVCboxesinaseriesof4tanks(reactors),inacontinuousflow.Thefollowingwasplacedineachreactor,asillustratedinFigure1:reactor1,class4waterfromtheCorumbataíRiver;reactor2,floatingaquaticmacrophyteEichhorniacrassipes,covering80%ofthewatersurface;reactor3,threedifferentsizesofgravel(a=25–50mm;b=6,4–12,7mm;c=2,4–4,8mm),plussoilofcerradoareaandSiresidue;reactor4,thesamethreesizesofgravelasinreactor3,plussoilofcerradoareaandpeat.Fourcollectionpointswereestablishedinthesystem,attheexitsofreactor1(P1),reactor2