给排水专业英文文献翻译

SewagetreatmentAbstractSewagetreatment,ordomesticwastewatertreatment,istheprocessofremoving\o"Contaminants"contaminantsfrom\o"Wastewater"wastewaterandhouseholdsewage,both\o"Surfacerunoff"runoff(\o"Effluents"effluents)anddomestic.Itincludesphysical,chemical,andbiologicalprocessestoremovephysical,chemicalandbiologicalcontaminants.Itsobjectiveistoproduceawastestream(ortreated\o"Effluent"effluent)andasolidwasteorsludgesuitablefordischargeorreusebackintotheenvironment.Thismaterialisofteninadvertentlycontaminatedwithmany\o"Toxic"toxicorganicandinorganiccompounds.Keywords:Sewagetreatment,fixed-filmandsuspended-growth,\o"Activatedsludge"ActivatedsludgeOriginsofsewageSewageiscreatedbyresidences,institutions,andcommercialandindustrialestablishments.Rawinfluent(sewage)includes\o"Householdwaste"householdwasteliquidfrom\o"Toilet"toilets,\o"Bathing"baths,\o"Shower"showers,\o"Kitchen"kitchens,\o"Sink"sinks,andsoforththatisdisposedofvia\o"Sanitarysewer"sewers.Inmanyareas,sewagealsoincludesliquidwastefromindustryandcommerce.Theseparationanddrainingofhouseholdwasteinto\o"Greywater"greywaterand\o"Blackwater(waste)"blackwaterisbecomingmorecommoninthedevelopedworld,withgreywaterbeingpermittedtobeusedforwateringplantsorrecycledforflushingtoilets.Alotofsewagealsoincludessomesurfacewaterfromroofsorhard-standingareas.Municipalwastewaterthereforeincludesresidential,commercial,andindustrialliquidwastedischarges,andmayinclude\o"Stormwater"stormwaterrunoff.Sewagesystemscapableofhandlingstormwaterareknownascombinedsystemsor\o"Combinedsewer"combinedsewers.Suchsystemsareusuallyavoidedsincetheycomplicateandtherebyreducetheefficiencyofsewagetreatmentplantsowingtotheirseasonality.Thevariabilityinflowalsoleadstooftenlargerthannecessary,andsubsequentlymoreexpensive,treatmentfacilities.Inaddition,heavystormsthatcontributemoreflowsthanthetreatmentplantcanhandlemayoverwhelmthesewagetreatmentsystem,causingaspilloroverflow.Itispreferabletohaveaseparate\o"Stormdrain"stormdrainsystemforstormwaterinareasthataredevelopedwithsewersystems.Asrainfallrunsoverthesurfaceofroofsandtheground,itmaypickupvariouscontaminantsincluding\o"Soil"soilparticlesandother\o"Sediment"sediment,\o"Heavymetals"heavymetals,\o"Organiccompound"organiccompounds,animalwaste,and\o"Oil"oiland\o"Petroleum"grease.Some\o"Jurisdiction"jurisdictionsrequirestormwatertoreceivesomeleveloftreatmentbeforebeingdischargeddirectlyintowaterways.Examplesoftreatmentprocessesusedforstormwaterincludesedimentationbasins,\o"Constructedwetland"wetlands,buriedconcretevaultswithvariouskindsoffilters,andvortexseparators(toremovecoarsesolids).ProcessoverviewSewagecanbetreatedclosetowhereitiscreated(in\o"Septictank"septictanks,\o"Biofilters"biofiltersor\o"Aerobictreatmentsystem"aerobictreatmentsystems),orcollectedandtransportedviaanetworkofpipesandpumpstationstoamunicipaltreatmentplant(see\o"Sanitarysewer"sewerageand\o"Sewagecollectionanddisposal"pipesandinfrastructure).Sewagecollectionandtreatmentistypicallysubjecttolocal,stateandfederalregulationsandstandards.Industrialsourcesofwastewateroftenrequirespecializedtreatmentprocesses(see\o"Industrialwastewatertreatment"Industrialwastewatertreatment).Conventionalsewagetreatmentmayinvolvethreestages,calledprimary,secondaryandtertiarytreatment.Primarytreatmentconsistsoftemporarilyholdingthesewageinaquiescentbasinwhereheavysolidscansettletothebottomwhileoil,greaseandlightersolidsfloattothesurface.Thesettledandfloatingmaterialsareremovedandtheremainingliquidmaybedischargedorsubjectedtosecondarytreatment.Secondarytreatmentremovesdissolvedandsuspendedbiologicalmatter.Secondarytreatmentistypicallyperformedby\o"Indigenous(ecology)"indigenous,water-bornemicro-organismsinamanagedhabitat.Secondarytreatmentmayrequireaseparationprocesstoremovethemicro-organismsfromthetreatedwaterpriortodischargeortertiarytreatment.Tertiarytreatmentissometimesdefinedasanythingmorethanprimaryandsecondarytreatment.Treatedwaterissometimesdisinfectedchemicallyorphysically(forexamplebylagoonsand\o"Microfiltration"microfiltration)priortodischargeintoa\o"Stream"stream,\o"River"river,\o"Bay"bay,\o"Lagoon"lagoonor\o"Wetland"wetland,oritcanbeusedforthe\o"Irrigation"irrigationofagolfcourse,greenwayorpark.Ifitissufficientlyclean,itcanalsobeusedfor\o"Groundwaterrecharge"groundwaterrechargeoragriculturalpurposes.Pre-treatmentPre-treatmentremovesmaterialsthatcanbeeasilycollectedfromtherawwastewaterbeforetheydamageorclogthepumpsandskimmersofprimarytreatmentclarifiers(trash,treelimbs,leaves,etc).ScreeningTheinfluentsewagewaterisstrainedtoremovealllargeobjectscarriedinthesewagestream.Thisismostcommonlydonewithanautomatedmechanicallyrakedbarscreeninmodernplantsservinglargepopulations,whilstinsmallerorlessmodernplantsamanuallycleanedscreenmaybeused.Therakingactionofamechanicalbarscreenistypicallypacedaccordingtotheaccumulationonthebarscreensand/orflowrate.Thesolidsarecollectedandlaterdisposedinalandfillorincinerated.GritremovalPre-treatmentmayincludeasandorgritchannelorchamberwherethevelocityoftheincomingwastewateriscarefullycontrolledtoallowsand,gritandstonestosettle.PrimarytreatmentIntheprimarysedimentationstage,sewageflowsthroughlargetanks,commonlycalled"primaryclarifiers"or"primarysedimentationtanks".Thetanksarelargeenoughthatsludgecansettleandfloatingmaterialsuchasgreaseandoilscanrisetothesurfaceandbeskimmedoff.Themainpurposeoftheprimarysedimentationstageistoproducebothagenerallyhomogeneousliquidcapableofbeingtreatedbiologicallyandasludgethatcanbeseparatelytreatedorprocessed.Primarysettlingtanksareusuallyequippedwithmechanicallydrivenscrapersthatcontinuallydrivethecollectedsludgetowardsahopperinthebaseofthetankfromwhereitcanbepumpedtofurthersludgetreatmentstages.Greaseandoilfromthefloatingmaterialcansometimesberecoveredfor\o"Saponification"saponification.SecondarytreatmentSecondarytreatmentisdesignedtosubstantiallydegradethebiologicalcontentofthesewagewhicharederivedfromhumanwaste,foodwaste,soapsanddetergent.Themajorityofmunicipalplantstreatthesettledsewageliquorusingaerobicbiologicalprocesses.Forthistobeeffective,the\o"Biota(ecology)"biotarequireboth\o"Oxygen"oxygenandasubstrateonwhichtolive.Thereareanumberofwaysinwhichthisisdone.Inallthesemethods,the\o"Bacteria"bacteriaand\o"Protozoa"protozoaconsumebiodegradablesolubleorganiccontaminants(e.g.\o"Sugar"sugars,fats,organicshort-chaincarbonmolecules,etc.)andbindmuchofthelesssolublefractionsinto\o"Flocculation"floc.Secondarytreatmentsystemsareclassifiedasfixed-filmandsuspended-growthFixed-filmORattachedgrowthsystemtreatmentprocessincluding\o"Tricklingfilter"tricklingfilterand\o"Rotatingbiologicalcontactors"rotatingbiologicalcontactorswherethebiomassgrowsonmediaandthesewagepassesoveritssurface.Insuspended-growthsystems,suchasactivatedsludge,thebiomassiswellmixedwiththesewageandcanbeoperatedinasmallerspacethanfixed-filmsystemsthattreatthesameamountofwater.However,fixed-filmsystemsaremoreabletocopewithdrasticchangesintheamountofbiologicalmaterialandcanprovidehigherremovalratesfororganicmaterialandsuspendedsolidsthansuspendedgrowthsystems.\o"Roughingfilter"Roughingfiltersareintendedtotreatparticularlystrongorvariableorganicloads,typicallyindustrial,toallowthemtothenbetreatedbyconventionalsecondarytreatmentprocesses.Characteristicsincludetypicallytall,circularfiltersfilledwithopensyntheticfiltermediatowhichwastewaterisappliedatarelativelyhighrate.Theyaredesignedtoallowhighhydraulicloadingandahighflow-throughofair.Onlargerinstallations,airisforcedthroughthemediausingblowers.Theresultantwastewaterisusuallywithinthenormalrangeforconventionaltreatmentprocesses.\o"Enlarge"ActivatedsludgeMainarticle:\o"Activatedsludge"ActivatedsludgeIngeneral,activatedsludgeplantsencompassavarietyofmechanismsandprocessesthatusedissolvedoxygentopromotethegrowthofbiologicalflocthatsubstantiallyremovesorganicmaterial.Theprocesstrapsparticulatematerialandcan,underidealconditions,convert\o"Ammonia"ammoniato\o"Nitrite"nitriteand\o"Nitrate"nitrateandultimatelyto\o"Nitrogen"nitrogengas,(seealso\o"Denitrification"denitrification).Surface-aeratedbasinsMostbiologicaloxidationprocessesfortreatingindustrialwastewatershaveincommontheuseofoxygen(orair)andmicrobialaction.Surface-aeratedbasinsachieve80to90%removalof\o"BiochemicalOxygenDemand"BiochemicalOxygenDemandwithretentiontimesof1to10days.Thebasinsmayrangeindepthfrom1.5to5.0metresandusemotor-drivenaeratorsfloatingonthesurfaceofthewastewater.Inanaeratedbasinsystem,theaeratorsprovidetwofunctions:theytransferairintothebasinsrequiredbythebiologicaloxidationreactions,andtheyprovidethemixingrequiredfordispersingtheairandforcontactingthereactants(thatis,oxygen,wastewaterandmicrobes).Typically,thefloatingsurfaceaeratorsareratedtodelivertheamountofairequivalentto1.8to2.7

kg\o"Oxygen"O2/\o"Watt-hour"kW·h.However,theydonotprovideasgoodmixingasisnormallyachievedinactivatedsludgesystemsandthereforeaeratedbasinsdonotachievethesameperformancelevelasactivatedsludgeunits.Biologicaloxidationprocessesaresensitivetotemperatureand,between0°Cand40°C,therateofbiologicalreactionsincreasewithtemperature.Mostsurfaceaeratedvesselsoperateatbetween4°Cand32°C.Filterbeds(oxidizingbeds)Mainarticle:\o"Tricklingfilter"TricklingfilterInolderplantsandplantsreceivingmorevariableloads,\o"Tricklingfilter"tricklingfilterbedsareusedwherethesettledsewageliquorisspreadontothesurfaceofadeepbedmadeupof\o"Coke(fuel)"coke(carbonizedcoal),\o"Limestone"limestonechipsorspeciallyfabricatedplasticmedia.Suchmediamusthavehighsurfaceareastosupportthebiofilsthatform.Theliquorisdistributedthroughperforatedrotatingarmsradiatingfromacentralpivot.Thedistributedliquortricklesthroughthisbedandiscollectedindrainsatthebase.Thesedrainsalsoprovideasourceofairwhichpercolatesupthroughthebed,keepingitaerobic.Biologicalfilmsofbacteria,protozoaandfungiformonthemedia’ssurfacesandeatorotherwisereducetheorganiccontent.This\o"Biofilm"biofilmisgrazedbyinsectlarvaeandwormswhichhelpmaintainanoptimalthickness.Overloadingofbedsincreasesthethicknessofthefilmleadingtocloggingofthefiltermediaandpondingonthesurface.BiologicalaeratedfiltersBiologicalAerated(orAnoxic)Filter(BAF)orBiofilterscombinefiltrationwithbiologicalcarbonreduction,\o"Nitrification"nitrificationordenitrification.BAFusuallyincludesareactorfilledwitha\o"Filter(water)"filtermedia.Themediaiseitherinsuspensionorsupportedbyagravellayeratthefootofthefilter.Thedualpurposeofthismediaistosupporthighlyactivebiomassthatisattachedtoitandtofiltersuspendedsolids.Carbonreductionandammoniaconversionoccursinaerobicmodeandsometimeachievedinasinglereactorwhilenitrateconversionoccursin\o"Hypoxia(environmental)"anoxicmode.BAFisoperatedeitherinupflowordownflowconfigurationdependingondesignspecifiedbymanufacturer.Membranebioreactors\o"Membranebioreactor"Membranebioreactors(MBR)combineactivatedsludgetreatmentwithamembraneliquid-solidseparationprocess.Themembranecomponentuseslowpressuremicrofiltrationorultrafiltrationmembranesandeliminatestheneedforclarificationandtertiaryfiltration.Themembranesaretypicallyimmersedintheaerationtank;however,someapplicationsutilizeaseparatemembranetank.OneofthekeybenefitsofanMBRsystemisthatiteffectivelyovercomesthelimitationsassociatedwithpoorsettlingofsludgeinconventional\o"Activatedsludge"activatedsludge(CAS)processes.Thetechnologypermitsbioreactoroperationwithconsiderablyhighermixedliquorsuspendedsolids(MLSS)concentrationthanCASsystems,whicharelimitedbysludgesettling.TheprocessistypicallyoperatedatMLSSintherangeof8,000–12,000

mg/L,whileCASareoperatedintherangeof2,000–3,000

mg/L.TheelevatedbiomassconcentrationintheMBRprocessallowsforveryeffectiveremovalofbothsolubleandparticulatebiodegradablematerialsathigherloadingrates.ThusincreasedSludgeRetentionTimes(SRTs)—usuallyexceeding15days—ensurecompletenitrificationeveninextremelycoldweather.ThecostofbuildingandoperatinganMBRisusuallyhigherthanconventionalwastewatertreatment.Membranefilterscanbeblindedwithgreaseorabradedbysuspendedgritandlackaclarifier'sflexibilitytopasspeakflows.Thetechnologyhasbecomeincreasinglypopularforreliablypretreatedwastestreamsandhasgainedwideracceptancewhereinfiltrationandinflowhavebeencontrolled,however,andthelife-cyclecostshavebeensteadilydecreasing.ThesmallfootprintofMBRsystems,andthehighqualityeffluentproduced,makethemparticularlyusefulforwaterreuseapplications.ThereareMBRplantsbeingbuiltthroughouttheworld,includingNorthLibrty,Iowa,Georgia,andCanada.SecondarysedimentationThefinalstepinthesecondarytreatmentstageistosettleoutthebiologicalflocorfiltermaterialandproducesewagewatercontainingverylowlevelsoforganicmaterialandsuspendedmatter.RotatingbiologicalcontactorsMainarticle:\o"Rotatingbiologicalcontactor"RotatingbiologicalcontactorRotatingbiologicalcontactors(RBCs)aremechanicalsecondarytreatmentsystems,whicharerobustandcapableofwithstandingsurgesinorganicload.RBCswerefirstinstalledin\o"Germany"Germanyin1960andhavesincebeendevelopedandrefinedintoareliableoperatingunit.Therotatingdiskssupportthegrowthofbacteriaandmicro-organismspresentinthesewage,whichbreakdownandstabiliseorganicpollutants.Tobesuccessful,micro-organismsneedbothoxygentoliveandfoodtogrow.Oxygenisobtainedfromtheatmosphereasthedisksrotate.Asthemicro-organismsgrow,theybuilduponthemediauntiltheyaresloughedoffduetoshearforcesprovidedbytherotatingdiscsinthesewage.EffluentfromtheRBCisthenpassedthroughfinalclarifierswherethemicro-organismsinsuspensionsettleasasludge.Thesludgeiswithdrawnfromtheclarifierforfurthertreatment.Afunctionallysimilarbiologicalfilteringsystemhasbecomepopularaspartofhome\o"Aquarium"aquariumfiltrationandpurification.Theaquariumwaterisdrawnupoutofthetankandthencascadedoverafreelyspinningcorrugatedfiber-meshwheelbeforepassingthroughamediafilterandbackintotheaquarium.Thespinningmeshwheeldevelopsa\o"Biofilm"biofilmcoatingofmicroorganismsthatfeedonthesuspendedwastesintheaquariumwaterandarealsoexposedtotheatmosphereasthewheelrotates.Thisisespeciallygoodatremovingwasteureaandammoniaurinatedintotheaquariumwaterbythefishandotheranimals.

污水处理摘要自然或生活污水处理，是指去除包含家庭排放和地面径流在内污水废水和地面污染物过程。它包含物理，化学和生物过程，消除物理，化学和生物污染物。其目标是集中产生废物流（或经处理污水）以及固体废物或污泥进行处理或再进入环境。这种污物通常是在无意中受到了许多有毒有机和无机物污染。关键词：污水处理;生物膜处理法和停顿增加生物处理法;活性污泥法污水起源污水是由个人住宅，机关，商业和工业机构产生。原进水（污水）包含家庭厕所，浴室，淋浴，厨房，水槽废液等等，这些水将经过污水管排放。在许多地域，污水也包含工业和商业污水。在发达国家，家居分别将污水排放为灰水和黑水已经越来越普遍，因为灰水能够用于浇灌植物或回收用来冲马桶。大量污水还包含一些屋顶流下水以及地表水。所以城市废水包含住宅，商业和工业排放废水，且可能包含雨水径流。具备处理雨水能力污水处理系统被称为合流排水系统。这种系统通常是不被普遍采取，因为它们复杂化而且因为其季节性，降低了污水处理厂效率。因为流量经常改变，也造成处理量往往大于必需，因而使处理设施更昂贵。另外，当遭遇暴雨时，过量雨水会造成污水处理能力不足，因而引发溢流。所以在设计排水管网时最好采取雨污分流系统。因为降雨流经屋顶和地面时，会带走包含土壤颗粒和其余沉积物，重金属，有机物，动物排泄物，污油和油脂等各种污染物质。所以有些地方会有法律要求在雨水排入河道之前要进行一些一定水平处理。比如以下对雨水进行处理：盆地沉淀处理，湿地过滤处理，混凝土地窖过滤处理，和旋涡分离器（去除粗固体）。过程概述污水能够在以下构筑物(化粪池，生物过滤器或好氧处理系统）附近被处理，或搜集并经过排水管网和泵站送至城市污水处理厂（见污水处理和管道和基础设施）。污水搜集和处理，通常取决于当地州和联邦法规和标准。起源于工业废水，往往需要专门处理过程（见工业废水处理）。常规污水处理可能包括三个阶段，一级处理，二级处理和三级处理。一级处理包含在沉淀池中短时停留，这么比较重固体就会沉到池底，而油，油脂，更轻固体则浮到水面。沉淀和浮动材料都将被去除，其余液体可被释放或继续二级处理。二级处理能够去除溶解和悬浮生物物质。二级处理通常由好氧或厌氧微生物进行。二级处理还可能需要一个分离过程，以去除残余微生物或进行三级处理。三级处理有时被界定为与一级和二级不一样过程。受处理水在排放到河流，海湾，泻湖或湿地前有时需要化学消毒或物理（比如泻湖和微滤）处理，或者能够用于浇灌高尔夫球场，绿色道路或公园。假如它足够清洁，也能够用于地下水回灌或农业用途。预处理预处理能够从原始废水除去垃圾，树枝，树叶等比较轻易搜集物质，以预防其损坏或阻塞水泵和一级处理澄清池处理。筛选进水污水必须消除随污水流进行大污染物。在服务大量人口当代化处理厂，经惯用自动倾斜格栅来达成这个目标。而小处理厂可能采取手动格栅。机械式格栅清污是经典以格栅污物积累或流量积累来进行。搜集到固体将被进行填埋或焚烧处理。除砂预处理可使包含沙子或砂砾在内物质经过控制速度在渠道或厅室内旋转流动，使砂，砂砾和石块沉淀。初级处理在初级沉淀阶段，污水流经一个大池子，俗称“初级澄清池”或“初级沉淀池”。这些池子需要足够大以令污泥能够沉淀而油和油脂等漂浮物能够上升到表面，并掠出池子。在初级沉淀阶段主要目标是提供一个均匀液态环境使微生物和污泥都能被处理。初级沉淀池，通常装配有机械驱动刮削泥器，不停推进将污泥搜集到底部污泥斗，从那里能够抽取污泥进行深入处理。油脂和石油漂浮物有时会回收进行皂化。二级处理二级处理设计是为了降低了污水中那些来自人类垃圾，食物渣滓，肥皂和洗涤剂产生生化生物污染。大多数市政都打算采取好氧生物方法处理污水处理问题。为了达成这个目标，生物既需要氧也需要生活底物。有多个方式来达成这个目标。在全部这些方法中，细菌和原生动物生物都能够降解消耗水中水溶性有机污染物（如糖，脂肪，有机短链碳分子等），将大部分可溶性组分结合成絮状。二级处理系统被分为生物膜处理法和停顿增加生物处理法。生物膜处理法和停顿增加生物处理法系统处理流程包含生物滤池和生物转盘，它们提供生物生长媒体以使污水流过时进行处理。在停顿增加生物处理法如活性污泥系统中，生物质能够与与污水充分混合，而且在处理等量污水时能够比膜系统采取更小空间操作。