Degradation-and-decolorization-of-reactive-red-X-3B-aqueous-solution-by-ozone

SeparationandPurificationTechnology74(2010)195–201ContentslistsavailableatScienceDirectSeparationandPurificationTechnologyjournalhomepage:www.elsevier.com/locate/seppurDegradationanddecolorizationofreactiveredX-3Baqueoussolutionbyozoneintegratedwithinternalmicro-electrolysisXin-ChaoRuan,Ming-YueLiu,Qing-FuZeng∗,Yan-HuaDingResearchCenterofEnvironmentalScience,WuhanUniversityofScienceandEngineering,1TextileRoad,Wuhan,Hubei430073,ChinaarticleinfoArticlehistory:Received29January2010Receivedinrevisedform1June2010Accepted2June2010Keywords:ReactiveredX-3BInternalmicro-electrolysisOzoneSynergeticeffectabstractOzoneintegratedwithinternalmicro-electrolysis(O3/IE)wasappliedtoelectrochemicallyoxidizereac-tiveredX-3Bowingtoitswell-establishedsynergeticeffectinthepresentstudy.Thefinalremovalratesofcolor,COD,TOCandAOXwerefoundtobe99%,85%,59%,and74%,respectively,whenthefollowingoptimalconditionswereused:dyestuffconcentrationof1g/LwithapHof9.0,areactiontemperatureof60◦C,400gofironscrapswiththediameterintherangeof0.9–2.0mmand10g/hozoneflowrate.ThedominantdegradationmechanismofreactiveredX-3Bwaselucidatedbytheadditionofradicalscav-enger/enhancer.TheresultsindicatedthattheformationofhydroxylradicalsinthepresenceofozonewasthemajorcontributingfactorinO3/IEsystem.©2010ElsevierB.V.Allrightsreserved.1.IntroductionSyntheticazodyestuffwitharomaticringshasbeenreleasedintotheenvironmentasdyewastewaterafterthebleaching,wash-inganddyeingprocessesoffabric,andhasbecomeanimportantsourceofenvironmentalpollutionduetoitshighcolor,hightoxic,recalcitrantandnon-biodegradablecharacteristics.Inrecentyears,methodsfordecolorizationanddegradationoftextileeffluentshavereceivedconsiderableattention.Variousconventionalphys-ical,chemical,electrochemical[1–4]andbiologicalmethodshavebeenexploredforthetreatmentofsyntheticandactualtextileeffluents.Internalmicro-electrolysis(IE),basedonreactionofgalvaniccelloxidationreduction,operatesontheprincipleverysimilartotheprincipleofelectrolysis[1,4]withtheexceptionthattheelect