绿色中国英语说绿色中国英语说 (6).ppt
Clean Waters and Green Mountains2.1 Water PollutionGreen ChinaGreen ChinaObjectivesLearnthebasicknowledgebehindwaterpollution01Beacquaintedwithsomeofthetechnologiesthatprotectourwaterresources02Current status of water resourcelWatercovers70%ofourplanetlOnly3%oftheworldswaterisfreshwaterWater pollution remains as the top environmental concern around the worldlRivers,lakesandaquifersaredryinguporbecomingtoopollutedtouse.What causes water pollution?Physical01Chemical02Biological03Radiological03What causes water pollution?lPhysicalPhysicalcontaminantsprimarilyimpactthephysicalappearanceorotherphysicalpropertiesofwater.Therearesediment(沉积物)ororganicmaterialsuspendedinthewateroflakes,riversandstreamsfromsoilerosion.What causes water pollution?lChemical Chemicalcontaminantsarenaturalorman-madecompounds,includingexcessnutrients,bleach,salts,pesticides,metals,drugs,andtoxinsproducedbybacteria.What causes water pollution?lBiological Biologicalcontaminantsareorganismsinwater,alsoreferredtoasmicrobesormicrobiologicalcontaminants,suchasbacteria,viruses,protozoa(原生动物),andparasites.What causes water pollution?lRadiological Radiologicalcontaminantsarechemicalelementswithanunbalancednumberofprotonsandneutronsresultinginunstableatomsthatcanemitradiation,includingcesium(铯),plutonium（钚）anduranium（铀）How do pollutants get into the waterbodies?Therearemainlytwotypesofwaterpollutionsources:point01non-point0201.Point source:01.Point source:Whencontaminationoriginatesfromasinglesource,itscalledpointsourcepollution.Examplesincludewastewater(alsocalledeffluent)dischargedlegallyorillegallybyamanufacturer,oilrefinery,orwastewatertreatmentfacility,aswellascontaminationfromleakingsepticsystems,chemicalandoilspills,andillegaldumping.02.Nonpoint source:02.Nonpoint source:Nonpointsourcepollutioniscontaminationderivedfromdiffusesources.Thesemayincludeagriculturalorstormwaterrunoffordebrisblownintowaterwaysfromland.Examples of water pollutionlEutrophication Eutrophicationisaleadingcauseofimpairmentofmanyfreshwaterecosystemsintheworld.Eutrophicationischaracterizedbyexcessiveplantandalgaegrowthduetotheexcessivenutrientsforplants,suchasnitrogenandphosphorus(磷).Forexample,alargebloomofblue-greenalgaetookplaceinTaihuLakein2007.Examples of water pollutionlEutrophication Examples of water pollutionlOcean acidification Oceanacidificationisanotherexample,theoceanabsorbsasmuchasaquarterofman-madecarbonemissions.WhenCO2isabsorbedbyseawater,aseriesofchemicalreactionsoccurresultingintheincreasedconcentrationofhydrogenionswhichleadstoincreasingacidity.Increasingacidityhaspossiblyharmfulconsequences,suchasdepressingtheimmuneresponsesofbluemusselsandcoralbleaching.Examples of water pollutionlOcean acidification How to protect our water resources?uChinahasissued“LawofthePeoplesRepublicofChinaonPreventionandControlofWaterPollution”,whichwasrevisedonJun,27th,2017topromoteprotectionandimprovementofthewaterenvironment.uTomaintainpublichealth,watermustbecarefullymanagedineverypartofthewatercycle.Wastewater treatment processAdvanced waste treatment techniques lBiogas production facilityLake restorationReferences1.http:/www.usgs.gov/media/images/distribution-water-and-above-earth2.http:/www.noaa.gov/education/resource-collections/ocean-coasts/ocean-acidification3.EncyclopdiaBritannica,Inc.4.Njogu,P.,Kinyua,R.,Muthoni,P.andNemoto,Y.(2015)BiogasProductionUsingWaterHyacinth(Eicchorniacrassipes)forElectricityGenerationinKenya.EnergyandPowerEngineering,7,209-216.5.Ramachandra,T.V.,S.Varghese,andK.S.Asulabha.EFFICACYOFREJUVENATIONOFLAKESINBENGALURU,INDIA.GreenChemistry&TechnologyLetters6.1(2020):14-26.Task1.Fromthevideo,canyoutheanswerstothefollowingthreequestions?WhatseemstobetheproblemforlakeWindermere?WhatarethecausesofthepollutioninlakeWindermere?Whatdidthegovernmentdotoimprovethewaterquality?2.Finishthetaskintheattachedworddocument.
