ComparisonofDissolvedAirFlotationandSedimentationinTreatmentofTypicalNorthChinaSourceWater

ThetreatmentoftypicalnorthChinawaterbydissolvedairflotation(DAF)andsedimentationprocesswasexamined.Apilotplantwithawatertreatmentcapacityof120m3/dconstructedintheJieyuanWaterTreatmentPlant(JWTP)ofTianjin,China,wasutilizedforthecomparisonofthetwoprocesses.Theresultsshowthatduringthepilottest,DAFprocesscanremoveparticlesandorganicmatermoreefficientlythansedimentationprocess.TheremovalrateforturbiditybyDAFprocessis5.5%higherthanthatbysedimentationinnormalturbidityperiod,and40%higherinlowturbidityperiod,itis5%~10%higherforremovalsofalgae,totalorganiccarbon(TOC),trihalomethaneformationpotential(THMFP)andbacteriainallperiods.Theremovalratesforturbidity,TOC,THMFP,algaeandbacteriabyDAFprocesscanreach95%,30%,20%,94%and97%respectively.Fromtheresultsofthepilottest,itcanbeconcludedthatDAFisafeasibleclarificationprocess,especiallyforsourcewaterwithlowturbidityandhighalgalblooming.