污水处理技术外文翻译

本科毕业设计外文文献及译文文献、资料题目：StudyonDisinfectionandAnti–microbialTechnologiesforDrinkingWater文献、资料来源：期刊文献、资料发表（出版）日期：2001.1.9院（部）：专业：给水排水工程班级：姓名：学号：指导教师：翻译日期：2010.3.30-1-外文文献：StudyonDisinfectionandAnti–microbialTechnologiesforDrinkingWaterZHUKun,FUXiaoYong(Dept.ofEnvironmentalEngineering,LANZhouRailwayUniversity,LANZhou730070,China)Abstract:Disinfectionby-productsproducedbythereactionbetweenchlorineanddissolvedorganiccompoundsandotherchemicalsareconsideredasaworryingprobleminthedrinkingwatertreatmentprocesssinceaseriesofmutageniccarcinogensubstancesareformedincludingtrihalomethanes(THMs).Amongthetesteddisinfectants(chlorine,ozone,chlorinedioxide,potassiumpermanganate,chloraminesandhydrogenperoxideetc.),chlorinedioxidehasprovedtobethemostfeasibleandeffectiveoxidantfordrinkingwatertreatmentandremovalofpathogensduetoitsoxidationefficiency,lowcostandsimplewayofutilization.Aseriesofexperimentsindicatethatchlorinedioxidecansignificantlyrestrainproductionoftrihalomethanes(THMs)andcontrolbacteriagrowthparticularlyforCryptosporidiumoocysts.Theexperimentsverifiedthatbothozoneandchlorinedioxideareabsolutelyvitaltoensurethatanymicroorganismsarisingfromfecalcontaminationofwaterstoragearedestroyed.Thepaperdiscussesoxidationcapacityofchlorinedioxide,especiallyforremovingpetroleumcompounds,whichisaffectedbyreactiontime,gasinjectionway,andpHoftreatedwater.Keywords:disinfection;oxidants;watertreatment;pathogens;chlorinedioxideCLCnumber:X523Documentcode:A1IntroductionChemicalandfiltrationprocessesaretwomainmethodsusedinChinafortreatingdrinkingwatermeanwhileUVradiationhasbeenusedsuccessfullyforwatertreatmentwithrelativelylowflowrate.Ontheindividualfamilylevel,usuallychemicaltreatmentisafeasiblealternative.Thefollowingguidelinesexistfortheselectionofsuitabledisinfectants:thereactionmustbestrongenoughtoextinctbacteriaandcontrolgrowthofmicro-organisms,removalofcontaminantsshouldbedonebydecomposition,evaporationorprecipitationetc,toeliminateordecreasethetoxicity,oxidantsorreactionby-productsshouldnotbeharmfultohumanhealth,andthepurificationprocessesshouldbepracticalandeconomical.Theobjectiveofthispaperisto-2-evaluateanddiscussavailabledisinfectantsfordrinkingwatertreatment.Thedifferentdisinfectantsarecomparedregardingpurificationefficienciesandapplicationapproaches.2ComparisonofDisinfectantsDisinfectants,suchaschlorine,chloramines,sodiumhypochlorous,chlorinedioxideandozoneetc.,wereprimarilyconsideredindrinkingwatertreatment.Theoxidationcapacitiesoftheseagentsmayberankedasfollowsinorderofdecreasedefficiency[1]:O3ClO2HOClOCl-NHCl2NH2ClReferringtoFiessinger′s[2]suggestion,thepropertiesofthesedisinfectantsarecomparedinTab.1.Chlorineisshowntobeanexcellentdisinfectanttopreventwaterbornediseasessuchastyphoidfeveroverlongperiods.Chlorinereactsnotonlywithinoxidation,butalsobyelectrophilicsubstitutiontoproduceavarietyofchlorinatedorganicby-products,particularlytrihalomethanes(THMs)andothermutagens.HereTHMsmainlyrefertochloroform,bromoform,dibromochloromathaneandbromodichloromathaneetc.Sincethe1970`s,theusageofCl2indrinkingwaterdisinfectionhasbeenquestionedwithozonebeingsubstitutedasthepreferreddisinfectantinthewatersupplyplants.But,ozonecouldnotbeintroducedtotheruralfarmercommunityduetoitshighcostsandshorthalf-life(15～20min.).Aswithotherdisinfectants,ozonationalsoleadstoformationoforganicby-productssuchasaldehyde,ketones,andcarboxylicacids,andalsomutagenicitymaybeinducedifbromicanionexists.Tab.1ComparisonofvariousoxidantsComparisonCl2ClO2O3KMnO4NH2ClH2O2THMformation+++-----Disinfectioneffects++++++++-+-+Enhancedbiodegradability++++++-+Tasteremoval-++++-+Ironandmanganese++++++++-+Ammonia+++-----Formationofmutagensortoxicsubstances-3-+++-+-+-+-+--noeffect;+littleeffect;++effect;+++largesteffectManystudieshavepointedoutthatdisinfectionisabsolutelyvitaltoensurethatanymicroorganismsarisingfromfecalcontaminationofwaterstoragearedestroyed.Theselectionoftheavailabledisinfectantsmustconcerntoreduceriskfrommicrobialcontaminationofdrinkingwaterandthepotentialincreaseinriskfromchemicalcontaminationthatresultfromusinganyofthedisinfectants.Thebiocidalefficiencyofcommonlyuseddisinfectants-ozone,chlorinedioxide,chlorineandchloraminesarerankedalmostwiththesameorderastheoxidizingcapacity,butthestabilityofthosearefollowingtheorderas[3]:ChloraminesChlorinedioxideChlorineOzone3PurificationoforganicpollutantsbychlorinedioxideAccordingtoWHOguidelinefordrinkingwaterquality,muchconsiderationshouldbepaidtobenzenehomologouscompounds;therefore,thestudyonpurificationeffectsofchlorinedioxideisfocusedonpetrochemicalpollutants.Aseriesofexperimentswerecarriedouttosimulatetheoxidationprocessesofcontaminatedwater.Thepollutedsolutionswerepreparedinadarkbarrel(10Lcapacity)ofsevenkindsofbenzenehomologouscompounds-Benzene,toluene,ethylbenzene,p-phenylmethane,o-phenylmethane,m-phenylmethaneandstyrene.Samplesweretakentodeterminetheinitialconcentrationofthecompoundspriortothetests.StandardchlorinedioxidesolutionwasproducedfromsodiumchloritereactedwithHClsolutionof10%[4].TheGR-16AGa