环境工程专业英语 课件 U3L2 Conventional Wastewater Treatment Process

ProfessionalEnglishforEnvironmentalEngineeringMainContents

IntroductiontoEnvironmentalEngineeringAirPollutionandControlWaterPollutionandControlSolidWasteandDisposalEnvironmentalImpactAssessmentEnvironmentalLaws，RegulationsandSustainableDevelopmentWaterPollutionandControl

ConventionalWastewaterTreatmentProcess

ProfessionalEnglishforEnvironmentalEngineering

Apointsourcepollutantisonethatreachesthewaterfromapipe,channel,oranyotherconfinedandlocalizedsource.Themostcommonexampleofapointsourceofpollutantsisapipethatdischargessewageintoastreamorriver.Mostofthesedischargesaretreatmentplanteffluents,thatis,treatedsewagefromawaterpollutioncontrolfacility:theystillcontainpollutantstosomedegree.ConventionalWastewaterTreatmentProcess

WaterPollution

Apollutantcanbeclassifiedaccordingtothenatureofitsoriginaseitherapointsourceordispersedsourcepollutant.Adispersedornonpointsourceisabroad,unconfinedareafromwhichpollutantsenterabodyofwater.Surfacerunofffromagriculturalareas,forexample,carriessilt,fertilizers,pesticides,andanimalwastesintostreams,butnotatoneparticularpoint.Thesematerialscanenterthewaterallalongastreamasitflowsthroughthearea.ConventionalWastewaterTreatmentProcess

WaterPollution

Apollutantcanbeclassifiedaccordingtothenatureofitsoriginaseitherapointsourceordispersedsourcepollutant.Acidicrunofffromminingareasisadispersedpollutant.Stormwaterdrainagesystemsintownsandcitiesarealsoconsideredtobedispersedsourcesofmanypollutantsbecause,eventhoughthepollutantsareoftenconveyedstreamsorlakesindrainagepipesorstormsewers,thereareusuallymanyofthesedischargescatteredoveralargearea.ConventionalWastewaterTreatmentProcess

WaterPollution

Apollutantcanbeclassifiedaccordingtothenatureofitsoriginaseitherapointsourceordispersedsourcepollutant.Pointsourcepollutantsareeasiertodealwiththandispersedsourcepollutants;thosefromapointsourcehavebeencollectedandconveyedtoasinglepointwheretheycanberemovedfromthewaterinatreatmentplant,andthepointdischargesfromtreatmentplantscaneasilybemonitoredbyregulatoryagencies.UndertheCleanWaterAct,adischargepermitisrequiredforallpointsources.ConventionalWastewaterTreatmentProcess

WaterPollution

Apollutantcanbeclassifiedaccordingtothenatureofitsoriginaseitherapointsourceordispersedsourcepollutant.《LawofthePeople'sRepublicofChinaonPreventionandControlofWaterPollution》（2008,2017）Pollutantsfromdispersedsourcesaremuchmoredifficulttocontrol.Manypeoplethinkthatsewageistheprimaryculpritinwaterpollutionproblems,butdispersedsourcescauseasignificantfractionofthewaterpollutionintheUnitedStates.Themosteffectivewaytocontrolthedispersedsourcesistoputappropriaterestrictionsonlanduse.ConventionalWastewaterTreatmentProcess

WaterPollution

Apollutantcanbeclassifiedaccordingtothenatureofitsoriginaseitherapointsourceordispersedsourcepollutant.NationalMajorFunctionOrientedZoning(MFOZ)

Inadditiontobeingclassifiedbytheirorigin,waterpollutantscanbeclassifiedintogroupsofsubstancesbasedprimarilyontheirenvironmentalorhealtheffects.Forexample,thefollowinglistidentifiesninespecifictypesofpollutants:PathogenicorganismsOxygen-demandingsubstancesPlantnutrientsToxicorganicsInorganicchemicalsSedimentRadioactivesubstancesHeatOilConventionalWastewaterTreatmentProcess

WaterPollution

Waterpollutantscanbeclassifiedintogroupsofsubstancesbasedprimarilyontheirenvironmentalorhealtheffects.Domesticsewageisaprimarysourceofthefirstthreetypesofpollutants.Pathogens,ordiseasecausingmicroorganisms,areexcretedinthefecesofinfectedpersonsandmaybecarriedintowatersreceivingsewagedischarges.Sewagefromcommunitieswithlargepopulationsisverylikelytocontainpathogensofsometype.ConventionalWastewaterTreatmentProcess

WaterPollution

DomesticsewageSewagealsocarriesoxygen-demandingsubstances—theorganicwastesthatexertabiochemicaloxygendemandastheyaredecomposedbymicrobes.ThisiscalledBODwhichchangestheecologicalbalanceinabodyofwaterbydepletingthedissolvedoxygen(DO)content.Nitrogenandphosphorus,themajorplantnutrients,areinsewage,too,aswellasinrunofffromfarmsandsuburbanlawns.ConventionalWastewaterTreatmentProcess

WaterPollution

DomesticsewageSewagealsocarriesoxygen-demandingsubstances—theorganicwastesthatexertabiochemicaloxygendemandastheyaredecomposedbymicrobes.ThisiscalledBODwhichchangestheecologicalbalanceinabodyofwaterbydepletingthedissolvedoxygen(DO)content.Nitrogenandphosphorus,themajorplantnutrients,areinsewage,too,aswellasinrunofffromfarmsandsuburbanlawns.ConventionalWastewaterTreatmentProcess

WaterPollution

DomesticsewageConventionalsewagetreatmentprocessessignificantlyreducetheamountofBODinsewage,butdonoteliminatethemcompletely.Certainviruses,inparticular,maybesomewhatresistanttothesewagedisinfectionprocess.(Avirusisanextremelysmallpathogenicorganismthatcanonlybeseenwithanelectronmicroscope.)Todecreasetheamountsofnitrogenandphosphorusinsewage,usuallysomeformofadvancedsewagetreatmentmustbeapplied.ConventionalWastewaterTreatmentProcess

WaterPollution

SewagetreatmentprocessesToxicorganicchemicals,primarilypesticides,maybecarriedintowaterinthesurfacerunofffromagriculturalareas.Perhapsthemostdangeroustypeisthefamilyofchemicalscalledchlorinatedhydrocarbons.Commonexamplesareknownbytheirtradenamesaschlordane,dieldrin,heptachlor,andtheinfamousDDT,whichhasbeenbannedintheUnitedStates.Theyareveryeffectivepoisonsagainstinsectsthatdamageagriculturalcrops.But,unfortunately,theycanalsokillfish,birds,andmammals,includinghumans.ConventionalWastewaterTreatmentProcess

WaterPollution

OtherpollutantsToxicorganicchemicalscanalsogetintowaterdirectlyfromindustrialactivity,eitherfromimproperhandlingofthechemicalsintheindustrialplantor,ashasbeenmorecommon,fromimproperandillegaldisposalofchemicalwastes.Propermanagementoftoxicandotherhazardouswastesisakeyenvironmentalissue,particularlywithrespecttotheprotectionofgroundwaterquality.Poisonousinorganicchemicals,specificallytheheavymetalgroupsuchaslead,mercuryandchromium,alsousuallyoriginatefromindustrialactivityandareconsideredhazardouswastes.ConventionalWastewaterTreatmentProcess

WaterPollution

OtherpollutantsOiliswashedintosurfacewatersinrunofffromroadsandparkinglots,andgroundwaterbepollutedfromleakingundergroundtanks.Accidentaloilspillsfromlargetransporttankersatseaoccasionallyoccur,causingsignificantenvironmentaldamage.Andblowoutaccidentsatoffshoreoilwellscanreleasemanythousandsoftonsofoilinashortperiodoftime.Oilspillsatseamayeventuallymovetowardshore,affectingaquaticlifeanddamagingrecreationareas.ConventionalWastewaterTreatmentProcess

WaterPollution

OtherpollutantsThepreventivestepsaremadeupof(i)Volumereductionsofwastewater(ii)StrengthreductionVolumereductioncanbeachievedby(a)conservationofwaterusedintheprocess,(b)segregationofdifferentstreamsintheprocess,(c)recyclingandreusingwaterusedintheprocess,(d)changingtheproductionscheduletodecreasewastewaterproducedand(e)avoidingslugorbatchdischarges.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

Waste-watertreatmentbasicallyinvolvestwosetsofmeasure:PreventiveCurativeStrengthreductioncanbeachievedby(a)equipmentmodificationsandprocesschanges,(b)segregation,equalizationandproportioningand(c)recoveryofimportantbyproductsfromwastestreams.Thepreventivemeasuresoutlinedabovearegeneralandoneormoreofthemmaybeapplied,dependingonthespecificapplication.Inatypicalpharmaceuticalindustry,manufacturingdrugintermediates,forexample,itwasfoundsufficienttosegregatedifferentwastestreamsandtreatthemostconcentratedoneforremovalofdissolvedinorganicchemical.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

Waste-watertreatmentbasicallyinvolvestwosetsofmeasure:PreventiveCurativeCurativemeasuresdealwiththeactualtreatmentofliquideffluentsbyphysical,chemicalandbiologicalmethods,ortheircombinations,dependingonthenatureofthepollutantsinthewasteandtheextenttowhichtheyaretoberemoved.Thedegreetowhichtreatmentisrequireddependsuponthemodeofdisposalofthetreatedwaste.Differentstandardshavebeenlaiddownforthedischargeofeffluentsintonaturalwaterbodies,municipalsewers,andintotheland.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

Waste-watertreatmentbasicallyinvolvestwosetsofmeasure:PreventiveCurativePhysicalmethodsaimatremovingsolidorliquidpollutants,basedontheirdensitydifferencefromwater.Theyareessentiallywastewaterclarificationmethodsandremovesuspendedorfloatingsolidsorliquids.Evaporationofwastewaterfollowedbyincineration,crystallizationorspaydryinghelpstorecovertheheatormaterialsdissolvedintheoriginalwastes.Thephenolincoke-oven-planteffluentsandcertainpharmaceuticalliquidwastescanbeextractedbybenzene,disopropyletherandothersolvents.Thesolventcanbeseparatedfromtheextractlayerbydistillationorwashingwithalkalis.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatmentOtherphysicalmethodsoftreatment(referredtoalsoasadvancedwaste-water-treatmentmethods)arereverseosmosis,electrodialysis,filtration,foamseparation,porous-bedfiltration,adsorption,etc.Theyhelpremovefineparticlesandorganicandinorganicdissolvedmaterials,resultinginbetterwaterqualityforreuseordisposal.Besides,someusefulmaterialscanalsoberecovered.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatmentReversegrilleFoamseparatorInthismethodcolloidalanddissolvedsolidsareconvertedintosettleablesolidsbymicro-organismsunderfavourableenvironmentalconditions,anaerobictreatmenttakesplaceinthetotalabsenceofoxygenandisaratherslowprocess.However,highlyconcentratedwastescanbehandledbythismethod.Anaerobicfiltrationanddigestionaresomeofitscategories.Aerobicbiological-treatmentmethodsincludetheactivated-sludgeprocess,trickling-filterprocessandstabilizationponds.Recentlyoxygeninsteadofairisbeingincreasinglyemployed.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatmentAerationtankSurfaceaeratorscanbeusedforbasindepthslessthan4m.Surfaceaeratorscanbeeasilyrepairedorreplaced.Alotofmist,however,isproducedinthevicinityofthetreatmentplants,causingundesirableodourswhenstrongsmellingwastesareprocessed.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatmentTricklingfiltersconsistofcircularbeds,2~5mhigh,filledwithporouslumpymaterialssuchashardcoke,slagorevenstone-metal.Thewastewaterisevenlydistributedonthesurfaceofthebedwitharotarysprinkler.Theslimybacterialfilmsformedonthesurfaceofthepackingtakeuporganicmaterialsfromthewastewaterasthelattertricklesdownthebed.Thewateriscollectedbelowthesupportplateorgratingandissenttoasettlingbasintoremovethesludge.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatmentPlastictubularorhoneycomb-shapedpackingscanbeusedforhighly-pollutedwastes.Thereislowerenergyconsumptioninthecaseoftricklingfiltersascomparedtoactivated-sludgeprocessesandtheyareeasiertomaintain.Ontheotherhand,capitalcostismoreandtreatmentcapacitylower.Therefore,itisbesttocombinetricklingfilterswiththeactivated-sludgeprocess.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatmentTricklingfiltersIndustrialeffluentsusuallycontainacids,alkalis,chlorides,phenols,sulphates,chromates,phosphate,andsaltsofmercury,lead,calcium,barium,zinc,etc.Thebestwaytoremovetheseistoincorporateinplantchangesinprocessdesignandoperation.Infact,recoveryanddisposalofthesepollutantsshouldbeincorporatedintheprocess-designstageitself.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatmentTheblowdownfromthecoolingtowercontainschromium(usuallyusedasamixturewithphosphateandzinc):thelimitofhexavalentchromiumfordischargeintosurfacewatersis0.1mg/L.Oneschemefortheremovalofchromiumconsistsofacidificationfollowedbyreductionwithferroussulphateandsubsequentlimedosing.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatmentIndustrialwatersusuallycontainacidsandbasesandneedtobeneutralizedbeforetheyaredischargedintowaterbodiesormunicipalsewers.Acids,whenneutralizedwithcausticsoda,givesolublesalts.Causticsoda,however,ismoreexpensivethanlimewhichis,therefore,usedforneutralizationofacidicwastes.However,elaboratestorageandgrindingfacilities,arerequired,thecostofwhichbalancesoutthehighercostofcausticsoda.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatmentWhenlimeisusedtoneutralizehydrochloricacidinindustrialwaste-water,itgivessolublecalciumchloridewhichisalsoundesirableandhastobetreatedfurtherwithsoda(sodiumcarbonate)togiveinsolublecalciumcarbonate.Allthisaddstothetotalsludgequantity.Neutralizationofalkalisisdonewithacalculatedquantityofsulphuricorhydrochloricacid.Tankslinedwithacid-alkali-resistantmaterialwithmildagitationbysimilarlylinedagitators,canbeusedforneutralization.Aresidencetimeof10~20minisconsideredsufficientforneutralization.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatmentFlocculationandprecipitationcanhelpreducetheorganicandinorganicloadbysettlingthesludgesorprecipitatesformed.Morethan90Percentofthedissolvedphosphatesand55~70percentoftheBODloadofdomesticsewagecanberemovedifdomesticwaste-water-clarificationiscombinedwithironandaluminiumsalts.Withclarificationalone,only25percentofBODcanberemoved.Dispersedpolymersandoilemulsionscanalsobebrokenupbyflocculation.Chromium(hexavalent)canbereducedtotrivalentchromiumwithS02gas,givingaprecipitateofchromiumsulphate.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatmentOxidationwithchlorineandsodiumhydrochlorateisusedforkillingpathogenicorganismsinthetreatedliquidwasteaswellasfortreatingindustrialwastes.Cyanidesareoxidizedtocyanatebychlorineorsodiumhypochlorite.Liquefiedchlorinefromcylindersisusedinmostapplications.ConventionalWastewaterTreatmentProcess

WasteWaterTreatment

CurativetreatmentPhysicalMethodsBiologicalWastewaterTreatmentChemicalWaste-WaterTreatment调解池Waterregulatingpond英语翻译的增译

语法需要引起的增译1.增加表示复数概念的词/词组

英语有特有的词汇复数表达，汉语多用一些词语来表达复数的概念，如“许多”、“大量”、“种种”、“若干”、“排排”、“朵朵”、“层层”等。(2)Radioactivematerialscanbeusedtolearnhowtheglandsandorgansofourbodiesfunction.

译文：放射性物质可用来查明各种腺体和器官的功能。(3)Picturestakenfromthespaceshowthechangesthatbothnaturalandhumanforceshavebroughtaboutontheearth'ssurface.译文：在太空拍摄的照片展示出大自然和人类的力量使地球表面发生的种种变化。

Translation

英语翻译的增译

语法需要引起的增译2.增加表示数量的数词、量词

(5)Ifyoupressaspringaxiallywithyourhandsatitsends,youwillfeelareactionfromit.

译文：如果你用双手从两端压一根弹簧，你就会感到弹簧有一种反作用力。

(6)Therevolutionoftheeartharoundthesuncausesthechangesoftheseasons.

译文：地球围绕太阳旋转，引起四季的交替。Translation

英语翻译的增译

语法需要引起的增译3.省略词的增译

由于英语具有避开使用重复词，翻译时，为了使译文符合原文和汉语表达，我们需要补全这些省略的词。

(7)Thebestconductorhastheleastresistanceandthepoorestthegreatest.

译文：最好的导体电阻最小，最差的导体电阻最大。(增加了省略的“导体电阻”一词)

(9)Careshouldbetakenatalltimestoprotecttheinstrumentfromthedustanddamp.

译文：应经常注意保护仪器，勿使其沾染灰尘，勿使其受潮。(根据句子内涵意思，增加了“勿使其沾染”、“勿使其受潮”)。Translation

英语翻译的增译

语法需要引起的增译4.非谓语动词、分词增译

非谓语动词、分词短语是英语中常见句式，在独立结构中用作状语，用来修饰主句中的谓语动词或主句，表示暗含的时间、原因、条件、方式、结果、让步或伴随意义，在翻译的时候，必须通过增译，准确译出这些非谓语动词、分词短语的确切意义。

(10)Possessinghighconductivityofheatandelectricity,aluminumfindswideapplicationinindustry.

译文：铝具有良好的导热性和导电性，故在工业上得到广泛的应用。(分词表示“原因”)

(11)Examiningadropofwaterunderthemicroscope，weshallseeahugenumberfbacteria.

译文：如果把一滴水放在显微镜下来观察，就会看到大量的细菌。(分词表示“假设”)。Translation

英语翻译的增译

语法需要引起的增译5.被动语态的增译

英语喜欢使用被动态表示主动的意思，一些描述客观事实的科技材料，也大量使用了被动句式，译者必须将其译为符合汉语习惯的主动态。

(12)Acomprehensivereviewismadecoveringvariousaspectsoftheapplication.

译文：本文旨在全面论述激光的应用。(增加了主语“本文”)

(13)Itisbelievedtobenaturalthatmoreandmoreengineershavecometoprefersyntheticmaterialtonaturalmaterial.

译文：越来越多的工程人员宁愿用合成材料而不用天然材料，人们相信这是很自然的。(增加了“人们”一词)。Translation

英语翻译的增译

语法需要引起的增译6.时态的增译

英语动词的时态种类繁多，往往是靠自身形态的变化或增加助动词加以实现，而汉语则不同，汉语没有词性的变化，时间概念可以体现在字里行间，或是通过借用一般的时态助词、表时间概念的副词，如“能”、“会”、“曾经”、“现在”、“将”等来实现，

(14)Researchhasshownaconnectionbetweensmokingandcancer.

译文：最近的研究己经证明抽烟和癌症间的关系。(增加了“已经”一词)

(15)Thephenolincoke-oven-planteffluentsandcertainpharmaceuticalliquidwastescanbeextractedbybenzene,diisopropyletherandothersolvents.

译文：焦炉废水和某些制药废液中的苯酚可用苯、二异丙基醚等溶剂萃取。(增加了“可用”一词)。Translation

英语翻译的增译

语法需要引起的增译6.动词语气的增译

英语动词可以表达陈述、祈使和虚拟三种语气。汉语语气的表达一般不需要加词，但需要增加词语才能反映出来，才能加强表达的气势或使译文更加通畅、可读。

(16)Inspecttheinstrumentcarefullyfordamage.Shouldtheinstrumentshowanysignsofdamage,fileaclaimwiththecarrierimmediately.

译文：请仔细检查仪器有无损坏现象。如果损坏，应立即向承运者提出索赔要求。(增加了“请”、“如果”两词)。Translation

英语翻译的增译

意义表达引起的增译1.名词的增译

英语有很多抽象化的名词，是由形容词或动词派生而来，表示动作或行为意义，在翻译过程中，要注意英语这样一个用词特点，将抽象名词具体化，或根据具体的汉语习惯搭配增加一些词/词组。

(1)Thistransfercontinuesuntilauniformtemperatureisreached,atwhichpointnofurtherenergytransferispossible.

译文：这一传递过程一直延续到温度均匀时为止，在温度均匀时能量便不可