專業(yè)英語詞匯及課文選段

Watersupply&drainageengineeringspecializedEnglish給水排水工程專業(yè)英語Schoolofcivil&transportationengineering土木與交通工程學院Facultyofmunicipalpublicequipment城市公用設備系High-risebuilding高層建筑Advancedwatertreatmentprocessing深度水處理工藝Waterqualitymonitoring水質(zhì)監(jiān)測Strongabsorption很強吸附能力Remove去除Waterresources水資源Naturalorganic天然有機物Conventionalwatertreatment常規(guī)水處理工藝Domestic生活waterpollution水污染wastewater廢水Industrial工業(yè)recognition意識freshwater淡水資源Drawlots抽簽waterdemand需水量Unbalanceecologicalenvironment生態(tài)環(huán)境不平衡Purifiedwater純凈水urban城鎮(zhèn)accountfor占有…的比例Toprotectwaterenvironmentisourresponsibility保護水環(huán)境我們的責任Waterresourcesandwatercrisis水資源與水危機Watershortage水資源短缺flowchart流程圖collidewith與…碰撞breakdown衰竭Groundwatersupplies地下水供應surfacewatersupplies地表水供應precipitation降雨waterwithdrawals水消失水撤退Ahighrateofwateruse高耗水率intake取水Globalwatercrisis全球水危機characteristicresidencetime特征停留時間potable可飲用的fungi真菌secretion分泌液Activatedcarbon活性炭chlorinedioxide二氧化氯Break–pointchlorination折點加氯high–efficient高效的Ozone臭氧aeration曝氣aggregate聚集凝聚coagulation凝結(jié)Stable穩(wěn)定的destabilize脫穩(wěn)flog絮體gravityforce重力Directfiltration直接過濾deposit沉積物supplypipenetwork給水管網(wǎng)turbidity濁度sedimentation沉淀池wateranalysis水質(zhì)分析color色度colloidalorganicmatter膠態(tài)有機物domesticpurposesuse家庭用水giveriseto引起導致powderactivatedcarbon活性炭Tap開關(guān)、龍頭aquifer含水層蓄水層watertable地下水位Extraction抽取取出提取萃取precipitation沉淀沉積物，沉降Runoff徑流流量流出口決賽evaporation蒸發(fā)transpiration蒸發(fā)散發(fā)蒸騰作用sleet冰雨雨夾雪Concentration集中濃縮濃度residue殘留物TDS（thetotaldissolvedsolids）總?cè)芙庑怨腆wTSS（thetotalsuspendedsolids）總懸浮性固體filtration過濾acidic酸性的，酸的organism生物體有機體microorganism微生物alkalinity堿度DO（dissolvedoxygen）溶解氧BOD（biochemistryoxygendemand）生物需氧量Decomposable可分解的oxidation氧化stabilize穩(wěn)定COD（chemicaloxygendemand）化學需氧量nitrogen氮particulate微粒顆粒biodegradable生物可降解的Wastewater廢水malodorous有惡臭的dryweatherflow枯季流量Overlandflow地表徑流effluent流出的discharge流量排放物Contaminant致污物preliminarytreatment預處理primarytreatment初級處理constituent構(gòu)分成分secondarytreatment二級處理Tertiarytreatment三級處理chemicalprecipitation化學沉淀Anaerobic厭氧的advancedoxidation高級氧化membranefiltration濾膜breakpointchlorination折點加氯denitrification反硝化作用脫氮作用ozone臭氧colloidal膠體的膠質(zhì)的advancedtreatment高級處理eutrophication富營養(yǎng)化作用pointsource點源Asupplyofwateriscriticaltothesurvivaloflife,asweknowit.Peopleneedwatertodrink,animalsneedwatertodrink,andplantsneedwatertodrink.Thebasicfunctionsofsocietyrequirewater:cleaningforpublichealth,consumptionforindustrialprocesses,andcoolingforelectricalgeneration.Inthislesson,wediscusswatersupplyintermsof:1groundwatersupplies2surfacewatersuppliesGroundwaterisanimportantdirectsourceofsupplythatistappedbywells,aswellasasignificantindirectsourcesincesurfacestreamsareoftensuppliedbysubterraneanwater.Nearthesurfaceoftheearth,inthezoneofaeration,soilporespacescontainbothairandwater.Thiszone,whichmayhavezerothicknessinswamplandsandbeseveralhundredfeetthickinmountainousregions,containsthreetypesofmoisture.Afterastorm,gravitywaterisintransitthroughthelargersoilporespaces.Capillarywaterisdrawnthroughsmallporespacesbymolecularforcesduringallexceptthedriestclimaticconditions.Moisture,fromthezoneofaerationcannotbetappedasawatersupplysource.Inthezoneofsaturation,locatedbelowthezoneofaeration,thesoilporesarefilledwithwater,andthisiswhatwecallgroundwater.Astratumthatcontainsasubstantialamountofgroundwateriscalledanaquifer.Atthesurfacebetweenthetwozones,calledthewatertableorphreaticsurface,thehydrostaticpressureinthegroundwaterisequaltotheatmosphericpressure.Anaquifermayextendtogreatdepths,butbecausetheweightofoverburdenmaterialgenerallyclosesporespaces,littlewaterisofwaterthatwilldrainfreelyfromanaquiferisknownasspecificyield.Surfacewatersuppliesarenotasreliableasgroundwatersourcessincequantitiesoftenfluctuatewidelyduringthecourseofayearevenaweek,andwaterqualityisaffectedbypollutionsources.Ifariverhasanaverageflowof10cubicfeetpersecond(cfs),thisdoesnotmeanthatacommunityusingthewatersupplycandependonhaving10cfsavailableatalltimes.Thevariationinflowmaybesogreatthatevenasmalldemandcannotbemetduringdryperiodsandsostoragefacilitiesmustbebuilttosavewaterduringwetterperiods.Reservoirsshouldbelargeenoughtoprovidedependablesupplies.However,reservoirsareexpensiveand,iftheyareunnecessarilylarge,representawasteofcommunityresources.MeasurementofwaterqualityQuantitativemeasurementsofpollutantsareobviouslynecessarybeforewaterpollutioncanbecontrolled.However,measurementofthesepollutantsisfraughtwithdifficulties.Sometimesspecificmaterialsresponsibleforthepollutionarenotknown.Moreover,thesepollutantsaregenerallypresentatlowconcentrations,andveryaccuratemethodsofdetectionarerequired.Onlyarepresentativesampleoftheanalyticaltestsavailabletomeasurewaterpollutionisdiscussedinthissection.Acompletevolumeofanalyticaltechniquesusedinwaterandwastewaterengineeringiscompiledasstandardmethodsfortheexaminationofwaterandwastewater.Thisvolumeistheresultofaneedforstandardizingtesttechniques.Itisconsidereddefinitiveinitsfieldandhastheweightoflegalauthority.Manywaterpollutantsaremeasuredintermsofmilligramsofthesubstanceperliter(mg/L).Inorderpublicationspollutantconcentrationsareexpressedaspartspremillion,aweight/weightparameter.Iftheliquidinvolvediswater,ppmisidenticalwithmg/L,sinceoneliter(L)ofwaterweights1000grams(g).Forpollutantspresentinverylowconcentrations(<10mg/L),ppmisapproximatelyequaltomg/L.However,becauseofthepossibilitythatsomewasteshavespecificgravitydifferentfromwater,mg/Lispreferredtoppm.Athirdcommonlyusedparameterispercent,aweight/weightrelationship.Notethat10000ppm=1%andisequalto10000mg/Lonlywhen1mL=1g.Mosttestsmaybeperformedonawatersampletakenfromthestream.Theprocess,bywhichthesampleisobtained,however,maygreatlyinfluencetheresult.Thethreebasictypesofsamplesaregrab,composite,andflow-weightedcomposite.SolidsWastewatertreatmentiscomplicatedbythedissolvedandsuspendedinorganicmaterialthewastewatercontains.Indiscussionofwatertreatment,bothdissolvedandsuspendedmaterialsarecalledsolids.Theseparationofthesesolidsfromthewaterisoneoftheprimaryobjectivesoftreatment.Strictlyspeaking,inwastewateranythingotherthanwaterisclassifiedassolids.Theusualdefinitionofsolids,however,istheresidueafterevaporationat103℃（slightlyhigherthantheboilingpointofwater）PhThepHofasolutionisameasureofhydrogenionconcentration,whichinturnisameasureofitsacidity.Thehydrogen-ionconcentrationinwaterisconnectedcloselywiththeextenttowhichwatermoleculesdissociate.Purewaterdissociatesslightlyintoequalconcentrationsofhydrogenandhydroxyl(OHˉ)icons.AlkalinityAparameterrelatedtopHisalkalinity,orthebufferingcapacityofthewateragainstacids.WaterthathasahighalkalinitycanacceptlargedosesofacidwithoutloweringthepHsignificantly.Waterswithlowalkalinity,suchasrainwater,canexperienceadropinthepHwithonlyaminoradditionofhydrogenion.DissolvedoxygenProbablythemostimportantmeasureofwaterqualityisthedissolvedoxygen(DO).Oxygen,althoughpoorlysolubleinwater,isfundamentaltoaquaticlife.WithoutfreeDO,streamsandlakesbecomeuninhabitabletogill-breathingaquaticorganisms.Theactualquantityofoxygen(othergasestoo)thatcanbepresentinsolutionisgovernedby(1)thesolubilityofthegas,(2)theconcentrationoftheimpuritiesinthewater(e.g.,salinity,suspendedsolids,etc.).Becausetherateofbiochemicalreactionsthatuseoxygenincreaseswithincreasingtemperature,dissolvedoxygenlevelstendtobemorecriticalinthesummermonths.Theproblemiscompoundedinsummermonthsbecausestreamflowsareusuallylower,andthusthetotalquantityofoxygenavailableisalsolower.Thepresenceofdissolvedoxygeninwastewaterisdesirablebecauseitpreventstheformationofnoxiousodors.Theamountofoxygendissolvedinwaterisusuallymeasuredeitherwithanoxygenprobeorbyiodometrictitration.ThelattermethodistheWinklertestsforDO,developedabout100yearsagoandthestandardagainstwhichallothermeasurementsarecompared.BiochemicaloxygendemandTherateatwhichoxygenisusedisperhapsevenmoreimportantthanthedeterminationofDO.Averylowrateofusewouldindicateeithercleanwater,thattheavailablemicroorganismsareuninterestedinconsumingtheavailableorganiccompounds,orthatthemicroorganismsaredeadordying.Therateofoxygenuseiscommonlyreferredtoasbiochemicaloxygendemand(BOD).BODisnotaspecificpollutantbutratherameasureoftheamountofoxygenrequiredbybacteriaandothermicroorganismsengagedinstabilizingdecomposableorganicmatter.Themostwidelyusedparameteroforganicpollutionappliedtobothwastewaterandsurfacewateristhe5-dayBOD.Thisdeterminationinvolvesthemeasurementofthedissolvedoxygenusedbymicroorganismsinthebiochemicaloxidationoforganicmatter.DespitethewidespreaduseoftheBODtest,ithasanumberoflimitations.Itishopedthat,throughthecontinuedeffortsofworkersinthefield,oneoftheothermeasuresoforganiccontent,orperhapsanewmeasure,willultimatelybeusedinitsplace.Why,then,ifthetestsuffersfromseriouslimitations,isfurtherspacedevotetoitinthistext?ThereasonisthatBODtestresultsarenowused(1)todeterminetheapproximatequantityofoxygenthatwillberequiredtobiologicallystabilizetheorganicmatterpresent,(2)todeterminethesizeofwaste-treatmentfacilities,(3)tomeasuretheefficiencyofsometreatmentprocesses,and(4)todeterminecompliancewithwastewaterdischargepermits.ChemicaloxygendemandAmongmanydrawbacksoftheBODtest,themostimportantisthatittakesfivedaystorun.Iftheorganiccompoundsareoxidizedchemicallyinsteadofbiologically,thetestcanbeshortenedconsiderably.Suchoxidationisaccomplishedwiththechemicaloxygendemand(COD)test.BecausenearlyallorganiccompoundsareoxidizedintheCODtestandonlysomearedecomposedduringtheBODtest,CODvaluesarealwayshigherthanBODvalued.Oneexampleofthisiswoodpulpingwaste,inwhichcompoundssuchascelluloseareeasilyoxidizedchemically(highCOD)butareveryslowtodecomposebiologically(lowBOD).TurbidityWaterthatisnotclearbut“dirty”,inthesensethatlighttransmissionisinhibited,isconsideredturbid.Inthetreatmentofwaterfordrinkingpurposes,turbidityisofgreatimportance,firstbecauseofaestheticconsiderationsandsecondbecausepathogenicorganismscanhideonthetinycolloidalparticles.Turbidityisanothertestusedtoindicatethequalityofwastedischargesandnaturalwaterswithrespecttocolloidalandresidualsuspendedmatter.Themeasurementofturbidityisbasedoncomparisonoftheintensityoflightscatteredbyasampletothelightscatteredbyareferencesuspensionunderthesameconditions.Formazinsuspensionsareusedastheprimaryreferencestandard.Theresultsofturbiditymeasurementsarereportedasnephelometricturbidityunits.Colloidalmatterwillscatterorabsorblightandthuspreventitstransmission.Itshouldbenotedthatthepresenceofairbubblesinthefluidwouldcauseerroneousturbidityreadings.Ingeneral,thereisnorelationshipbetweenturbidityandtheconcentrationoftotalsuspendedsolidsinuntreatedwastewater.Thereis,however,areasonablerelationshipbetweenturbidityandtotalsuspendedsolidsforthesettledandfilteredsecondaryeffluentfromtheactivatedsludgeprocess.FundamentalsofwastewatertreatmentEverycommunityproducesbothliquidandsolidwastesandairemissions.Theliquidwaste—wastewater—isessentiallythewatersupplyofthecommunityafterithasbeenusedinavarietyofapplications.Fromthestandpointofsourcesofgeneration,wastewatermaybedefinedasacombinationoftheliquidorwater-carriedwastesremovedfromresidences,institutions,andcommercialandindustrialestablishments,togetherwithsuchgroundwater,surfacewater,andstormwaterasmaybepresent.FuturetrendsinwastewatertreatmentIntheU.S.EPANeedsAssessmentSurvey,thetotaltreatmentplantd