英语演讲稿-水污染-英文PPT

waterenvironmentWateristhesourceofallthings•It’stheonlywater,butit’stheliquidwonderthatmakesourworldpossible.•Waterisabletodissolvemoresubstancesthananyotherliquid.•It’stakesalotofwatertokeeplifegoing.123Somedatawateruse&pollutionwhatcanwedo71%ofearth’ssurfaceiscoveredwithwaterArethewatersourcesabundant?lessthan3%OftotalwaterLowlayer0.3%offreshwater•Chinawaterresourcerankfourthintheworld.•Chinaisn'trichinwaterresources.•Obviously,theprospectofChinesewaterresourcesisn'toptimistic.22001047334788001100026600050001000015000200002500030000ChinaNorthchinaSouthChinaWorldUSARussia(m3/yr/ca)WaterIssuesinChina•withwaterresourcespercapitabeing2200m3orso,only1/4ofthatoftheworld.waterresourcespercapita北方人口:47%GDP:44%水资源:22%南方人口:53%GDP:56%水资源:78%水资源分布不均南方南方北方北方水资源水资源土地资源土地资源020406080100%020406080100%81%19%38%62%South:population53%waterresource:78%•North:population:47%waterresource:22%UnevendistributionofwaterresourcesWaterisconsideredpollutedifasubstanceorconditionispresentthatrendersthewateruselessforaparticularpurposeThesourcesofwaterpollutionDirectsourceseffluentoutfallsfromfactories,refineries(精炼厂）,wastetreatmentplants...Indirectsourcescontaminantsthatenterthewatersupplyfromsoils/groundwatersystemsandfromtheatmosphereviarainwater...AgriculturalWaterUseFourcommonirrigationmethods:Surface/FloodRequiresextensivecanalsystemsSprayUsepumpsTrickleStrategicallyplacesopeningsSub-irrigationPipescanbeusedfordrainageaswellExcessivefertilizerusemayleadtoeutrophication（水体富营养化）inmanyaquatichabitats.Agriculturalrunofffromlarge,openexpansesismajorsourceofwaterpollution.AgriculturalWaterPollutionIndustrialWaterUseAccountsfornearly50%ofallwaterwithdrawalinU.S.,and23%worldwide.90%ofwaterusedbyindustryisforcooling,andisreturnedtothesource.Verylittleactuallyconsumed.Mostprocessesinvolveheatexchange.Waterusedtodissipateandtransportwaste.ToxicandoverloadwastesleadStreamandlakedegradation.IndustrialWaterPollutionAllkindsofindustrygeneratetradewaste(工业废水）IronandsteelindustryFoodindustryComplexorganicchemicalsindustryNuclearindustryPollutants:organics,oil,metal,acidMayrequirespecialwastewatertreatment.DomesticWaterUse70%usedassolventtocarrywastes.30%usedforlawnandgarden.Verysmallfractionusedfordrinking.Naturalpurificationprocessescannotcopewithhighlyconcentratedurbanwastes.Mustbetreatedbeforerelease.DomesticwaterpollutionWastewaterfromBathing,dishes,toiletsNotoxicsubstance,abundantinnutrientswithnitrogen(N，氮）andphosphorus(P，磷）Eutrophication（水体富营养化）Trashorgarbage(e.g.paper,plastic,orfoodwaste)discardedbypeopleontheground,alongwithaccidentalorintentionaldumpingofrubbish,thatarewashedbyrainfallintostormdrainsandeventuallydischargedintosurfacewaters.Forgovernments•1.Toestablishurbansewagetreatmentsystem(城市污水处理系统)•2.TorestructureIndustrial•3.Toencouragethedevelopmentofnewwatersources•4.Tostrengthenlegislation,severepunishmentForplants•1.Toreducewaterconsumption•2.Tobuyequipmentofsewagetreatment•3.Don‘tdischargesewageintowater•4.TousewaterrecyclingsystemForindividuals•1.Don’tusecleanerconcludeP•2.Don’tthrowthegarbageintotherivers•3.Topromoteawarenessofpreservingwaterresources•4.TotellthepersonsaroundyoutoprotectthewaterresourcesWorldWaterDay(WorldDayforWater)•OnMarch22•theUnitedNationsGeneralAssembly（联合国大会）in1993•aim:toarousepublic’sawarenessofeconomizingwatersources,andtoprotectit•onethemeperyear•2011:waterforcitiesThankyou!