環(huán)境工程專業(yè)英語 課件 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調(diào)解池Waterregulatingpond英語翻譯的增譯

語法需要引起的增譯1.增加表示復(fù)數(shù)概念的詞/詞組

英語有特有的詞匯復(fù)數(shù)表達(dá)，漢語多用一些詞語來表達(dá)復(fù)數(shù)的概念，如“許多”、“大量”、“種種”、“若干”、“排排”、“朵朵”、“層層”等。(2)Radioactivematerialscanbeusedtolearnhowtheglandsandorgansofourbodiesfunction.

譯文：放射性物質(zhì)可用來查明各種腺體和器官的功能。(3)Picturestakenfromthespaceshowthechangesthatbothnaturalandhumanforceshavebroughtaboutontheearth'ssurface.譯文：在太空拍攝的照片展示出大自然和人類的力量使地球表面發(fā)生的種種變化。

Translation

英語翻譯的增譯

語法需要引起的增譯2.增加表示數(shù)量的數(shù)詞、量詞

(5)Ifyoupressaspringaxiallywithyourhandsatitsends,youwillfeelareactionfromit.

譯文：如果你用雙手從兩端壓一根彈簧，你就會(huì)感到彈簧有一種反作用力。

(6)Therevolutionoftheeartharoundthesuncausesthechangesoftheseasons.

譯文：地球圍繞太陽旋轉(zhuǎn)，引起四季的交替。Translation

英語翻譯的增譯

語法需要引起的增譯3.省略詞的增譯

由于英語具有避開使用重復(fù)詞，翻譯時(shí)，為了使譯文符合原文和漢語表達(dá)，我們需要補(bǔ)全這些省略的詞。

(7)Thebestconductorhastheleastresistanceandthepoorestthegreatest.

譯文：最好的導(dǎo)體電阻最小，最差的導(dǎo)體電阻最大。(增加了省略的“導(dǎo)體電阻”一詞)

(9)Careshouldbetakenatalltimestoprotecttheinstrumentfromthedustanddamp.

譯文：應(yīng)經(jīng)常注意保護(hù)儀器，勿使其沾染灰塵，勿使其受潮。(根據(jù)句子內(nèi)涵意思，增加了“勿使其沾染”、“勿使其受潮”)。Translation

英語翻譯的增譯

語法需要引起的增譯4.非謂語動(dòng)詞、分詞增譯

非謂語動(dòng)詞、分詞短語是英語中常見句式，在獨(dú)立結(jié)構(gòu)中用作狀語，用來修飾主句中的謂語動(dòng)詞或主句，表示暗含的時(shí)間、原因、條件、方式、結(jié)果、讓步或伴隨意義，在翻譯的時(shí)候，必須通過增譯，準(zhǔn)確譯出這些非謂語動(dòng)詞、分詞短語的確切意義。

(10)Possessinghighconductivityofheatandelectricity,aluminumfindswideapplicationinindustry.

譯文：鋁具有良好的導(dǎo)熱性和導(dǎo)電性，故在工業(yè)上得到廣泛的應(yīng)用。(分詞表示“原因”)

(11)Examiningadropofwaterunderthemicroscope，weshallseeahugenumberfbacteria.

譯文：如果把一滴水放在顯微鏡下來觀察，就會(huì)看到大量的細(xì)菌。(分詞表示“假設(shè)”)。Translation

英語翻譯的增譯

語法需要引起的增譯5.被動(dòng)語態(tài)的增譯

英語喜歡使用被動(dòng)態(tài)表示主動(dòng)的意思，一些描述客觀事實(shí)的科技材料，也大量使用了被動(dòng)句式，譯者必須將其譯為符合漢語習(xí)慣的主動(dòng)態(tài)。

(12)Acomprehensivereviewismadecoveringvariousaspectsoftheapplication.

譯文：本文旨在全面論述激光的應(yīng)用。(增加了主語“本文”)

(13)Itisbelievedtobenaturalthatmoreandmoreengineershavecometoprefersyntheticmaterialtonaturalmaterial.

譯文：越來越多的工程人員寧愿用合成材料而不用天然材料，人們相信這是很自然的。(增加了“人們”一詞)。Translation

英語翻譯的增譯

語法需要引起的增譯6.時(shí)態(tài)的增譯

英語動(dòng)詞的時(shí)態(tài)種類繁多，往往是靠自身形態(tài)的變化或增加助動(dòng)詞加以實(shí)現(xiàn)，而漢語則不同，漢語沒有詞性的變化，時(shí)間概念可以體現(xiàn)在字里行間，或是通過借用一般的時(shí)態(tài)助詞、表時(shí)間概念的副詞，如“能”、“會(huì)”、“曾經(jīng)”、“現(xiàn)在”、“將”等來實(shí)現(xiàn)，

(14)Researchhasshownaconnectionbetweensmokingandcancer.

譯文：最近的研究己經(jīng)證明抽煙和癌癥間的關(guān)系。(增加了“已經(jīng)”一詞)

(15)Thephenolincoke-oven-planteffluentsandcertainpharmaceuticalliquidwastescanbeextractedbybenzene,diisopropyletherandothersolvents.

譯文：焦?fàn)t廢水和某些制藥廢液中的苯酚可用苯、二異丙基醚等溶劑萃取。(增加了“可用”一詞)。Translation

英語翻譯的增譯

語法需要引起的增譯6.動(dòng)詞語氣的增譯

英語動(dòng)詞可以表達(dá)陳述、祈使和虛擬三種語氣。漢語語氣的表達(dá)一般不需要加詞，但需要增加詞語才能反映出來，才能加強(qiáng)表達(dá)的氣勢或使譯文更加通暢、可讀。

(16)Inspecttheinstrumentcarefullyfordamage.Shouldtheinstrumentshowanysignsofdamage,fileaclaimwiththecarrierimmediately.

譯文：請仔細(xì)檢查儀器有無損壞現(xiàn)象。如果損壞，應(yīng)立即向承運(yùn)者提出索賠要求。(增加了“請”、“如果”兩詞)。Translation

英語翻譯的增譯

意義表達(dá)引起的增譯1.名詞的增譯

英語有很多抽象化的名詞，是由形容詞或動(dòng)詞派生而來，表示動(dòng)作或行為意義，在翻譯過程中，要注意英語這樣一個(gè)用詞特點(diǎn)，將抽象名詞具體化，或根據(jù)具體的漢語習(xí)慣搭配增加一些詞/詞組。

(1)Thistransfercontinuesuntilauniformtemperatureisreached,atwhichpointnofurtherenergytransferispossible.

譯文：這一傳遞過程一直延續(xù)到溫度均勻時(shí)為止，在溫度均勻時(shí)能量便不可