氮印染毒性英文

ToxicityandintermediatesofC.I.DirectRed28dyethroughsequentialanaerobic/aerobictreatmentDeliaTeresaSponza*,MustafaIs¸ıkDokuzEylulUniversity,EngineeringFaculty,EnvironmentalEngineeringDepartment,BucaKaynaklarCampus,35160Izmir,TurkeyReceived8October2004;accepted8December2004AbstractToxicityandintermediatesofC.IDirectRed28(DR28)azodyewasinvestigatedthroughdecolorizationandmineralizationofDR28azodyeinasequentialupflowanaerobicsludgeblanketreactor(UASB)/continuousstirredtankreactor(CSTR)system.SystemperformancewasdeterminedbymonitoringtheconventionalparameterssuchasCOD,inertCOD,TOC,color,ammonia,nitrate,volatilefattyacid(VFA)andtotalaromaticamine(TAA)analyses.Understeadystateconditionscolorwaseffectivelyremovedunderanaerobicconditions.TotalaromaticaminescouldbemainlyremovedunderaerobicconditionswhileCODwasremovedunderbothanaerobicandaerobicconditions.Samplesfromeffluentsofthesystemwereanalyzedbyhighperformanceliquidchromatography–diodearraydetection(HPLC–DAD)andgaschromatography–massspectra(GC–MS)methodstodetecttheintermediatesproducedintheeffluentsofanaerobicandaerobicsteps.Benzidineproducedunderanaerobicconditionswasmineralizedsignificantlyunderaerobicconditions.Simplequalitativeanalyses,NO
3–N,HPLCandGCanalysesshowedthatDirectRed28couldbechieflymineralizedbytheanaerobic/aerobicsequentialsystem.Reductionoftoxicitywasalsoobservedinanaerobictoxicityassays(ATA)respiration/inhibitionandDaphniamagnateststhroughthecontinuousoperationofanaerobic/aerobicsequentialtreatmentsystem.#2005ElsevierLtd.Allrightsreserved.Keywords:Toxicity;DirectRed28;Benzidine;Testmicroorganism;Biologicaltreatment1.IntroductionAzodyesconsistofadiazotizedaminecoupledtoanamineoraphenolandcontainoneormoreazolinkages.Theyarethelargestclass(60–70%)ofdyeswiththegreatestvarietyofcolors[1].Approximately10–15%ofthedyesarereleasedintotheenvironmentduringdyeingofdifferentsubstrates,suchassyntheticandnaturaltextilefibres,plastics,leather,paper,mineraloils,waxes,andevenfoodstuffsandcosmetics[2].Thecriterionofharmfulnessofbenzidinebaseddyesisthepossibilityofsplittingintocarcinogenicamines[3].Approximately,itwasdeterminedthat130of3200azodyesinusehaveproducedcarcinogenicaromaticaminesbecauseofreductivedegradationofthese[4,5].Theseamineshavebeendefinedastheso-calledMaximalArbentsplatzKonzentration(MAK)IIIA1amines(e.g.benzidine)andMAKIIIA2amines(e.g.o-toludine)[6–9]aswellasInternationalAgencyforResearchandCancer(IARC)andEcologicalandToxicologicalAssocia-tionoftheDyestuffsManufacturingGroup(ETAD)1(4-amiobiphenyl,2Naphthylamine).AsshownbenzidinetakesplaceincarcinogenicGroup1andistoxictohumans[6–9].SeveralEuropeancountries,mainly,includingGermanydefinitelyforbidthepresenceofMAKaminesintextileproducts.Currently,alltheEuropeanUnionlegalandcustomsregulationswhicharebeingpreparedfollowthistrendandprohibitthemanufactureandsaleofbenzidinebasedazodyesfromSeptember2003[10].InTurkeytheTurkishgovernmentbannedtheutilizationof130azodyesfrom1March1995duetorelevantaromaticaminesandprohibitedtheuseofthesedyesinthetextilemarket[11].HowevertheyarestillusedintextiledyeingprocessesduetotheirefficiencyofdyingandcostinTurkeyandinsomecountrieslikeIndia[9,12,13].DR28isusedincotton,jute,leather,paper,silkandwoolindustries[14].Itisabenzidinebasedazodyeamong130azo(2005)2735–2744*Correspondingauthor.Tel.:[phone]x1119;fax:[phone].E-mailaddress:[e-mail](D.T.Sponza).0032-9592/$–seefrontmatter#2005ElsevierLtd.Allrightsreserved.doi:10.1016/j.procbio.2004.12.016dyesandstillinuseintextileindustriesalthoughitisabannedazodye.Pieleszreportedthattheuseandmanufactureofbenzidinecontinueduntilrecentlyduetolowcostalthoughthebanonbenzidinewasintroducedin1997[15].ThecapabilitytoformcarcinogenicaminessuchasbenzidinethroughcleavageofoneormoreazogroupsinthereasonwhytheyallfallunderthecategoryofbannedazodyeslikeDR28[15].TherecalcitranceofDB28azodyehasbeenattributedtothepresenceofaminobiphenylgroupandazobonds,twofeaturesgenerallyconsideredasxenobiotic[16].Aromaticaminesaregenerallynotdegradedandaccumu-latedunderanaerobicconditions[17,18],withtheexceptionofafewaromaticaminescharacterizedbythepresenceofhydroxyland/orcarboxylgroups[19,20].Mineralizationofthearomaticaminesbyaerobicbacteriaandaerobicsludgeintreatmentplantsismorecommonand,therefore,aerobicconditionsarepreferabletodegradetheaccumulatedaromaticamines[21–24].Theaerobicstageofcombinedanaerobic/aerobictreatmentofdyewasteseliminatedthechemicaloxygendemand(COD),attributedtoremovalofaromaticamines,whichareanaerobicallyrecalcitrant[25,26].Aromaticaminesaregenerallynotdegradedandaccumulatedunderanaerobicconditions[27,28].Mineraliza-tionofthearomaticaminesbyaerobicbacteriaandaerobicsludgeintreatmentplantsismorecommonand,therefore,aerobicconditionsarepreferredtodegradetheaccumulatedaromaticamines[29,30].ColorwasremovedunderanaerobicconditionswhilethecompletemineralizationofaminestoCO2,H2OandNH3occursunderaerobicconditions.Thereforeanaerobictreatmentfollowedbyaerobictreatmentcanbeusedtodecompose