可持续发展经济ppt介绍之循环经济讲解environment.ppt

1,WaterPollution,Reference:G.TylerMillersLivingintheEnvironment14thEdition,PreparedbyShohailMotahirChoudhury,2,KeyConcepts,Types,sources,andeffectsofwaterpollutants,Majorpollutionproblemsofsurfacewater,Majorpollutionproblemsofgroundwater,Reductionandpreventionofwaterpollution,Drinkingwaterquality,3,Types,Effects,andSourcesofWaterPollution,Waterispollutedbyinfectiousbacteria,inorganicandorganicchemicals,andexcessheat.Waterpollutionisanychemical,biological,orphysicalchangeinwaterqualitythathasaharmfuleffectonlivingorganisms.TheWHOestimatesthat3.4millionpeopledieprematurelyeachyearfromwaterbornediseases.IntheU.S.,anestimated1.5millionpeopleayearbecomeillfrominfectiousagents.,4,Scientistsmonitorwaterqualitybyusingbacterialcounts,chemicalanalysis,andindicatororganisms.Onemethodofmeasuringwaterqualityinvolvesmeasuringthenumberofcoloniesoffecalcoliformbacteriapresentinawatersample.Drinkingwatershouldnotcontainanycolonies/100milliliters,Chemicalanalysisincludescheckinginorganicandorganicchemicalspresent,sedimentcontent,andturbidityofwater.Indicatorspeciesarelivingorganismsthataremonitoredtodeterminelevelsofpollution.,5,SourcesofWaterPollution,Pointsources,Nonpointsources,Waterquality,6,PointandNonpointSources,7,Sourcesofwaterpollution,Theleadingsourcesofwaterpollutionareagriculture,industries,andmining.1.Agriculturalactivitiesaretheleadingcauseofwaterpollutionfromerosion,overgrazing,fertilizersandpesticides,andexcesssaltfromirrigatedsoils.2.Industrialfacilitiesareanotherlargesourceofwaterpollution,andminingisathirdsource.,8,Oneofeveryfivepeopleintheworldlacksaccesstosafedrinkingwater.Ninety-fivepercentofpeopleindevelopedcountriesand74%ofpeopleindevelopingcountrieshaveaccesstocleandrinkingwater.Inawarmerworld,toomuchrainandtoolittleraincanincreasewaterpollution.,9,PollutionofFreshwaterStreams,Streamscanrecoverfrommoderatelevelsofdegradablewaterpollutantsiftheflowsarenotreduced.1.Acombinationofdilutionandbiodegradationcanallowrecoveryofstreampollution2.Thebreakdownofpollutantsbybacteriacreatesanoxygensagcurve.Organismsthathaveahighoxygendemandcantsurviveinthecurve.3.Volumeofthestream,volumeofwastesentering,flowrate,temperature,andpHlevelsallaffecthowgreatasagcurveisproduced.,10,OxygenSagCurve,11,WaterPollution:Now,Mostdevelopedcountrieshavereducedpointsourcepollution,buttoxicchemicalsandpollutionfromnon-pointsourcesarestillproblems.Streampollutioninmostdevelopingcountriesisaseriousandgrowingproblem.Halfoftheworlds500majorriversareheavilypolluted,andmostofthemrunthroughdevelopingcountrieswherewastetreatmentisminimalornonexistent.Forexample:Religiousbeliefs,culturaltraditions,poverty,littleeconomicdevelopment,andalargepopulationinteracttocauseseverepollutionoftheGangesRiverinIndia.,12,PollutionofLakes,13,TheGreatLakes,Fig.22-8p.500,14,GroundwaterPollution:Causes,Lowflowrates,Fewbacteria,Coldtemperatures,Coalstripminerunoff,Pumpingwell,Wastelagoon,Accidentalspills,Groundwaterflow,Confinedaquifer,Discharge,Leakagefromfaultycasing,Hazardouswasteinjectionwell,Pesticides,Gasolinestation,Buriedgasolineandsolventtank,Sewer,Cesspoolseptictank,De-icingroadsalt,Unconfinedfreshwateraquifer,Confinedfreshwateraquifer,Waterpumpingwell,Landfill,Lowoxygen,15,PollutionofGroundwater,Expertsrategroundwaterpollutionasalow-riskecologicalproblem;itisratedasahigh-riskhealthproblem.TheextentofgroundwatercontaminationisgenerallyunknownPreventionisthemosteffectiveandaffordablewaytoprotectgroundwaterfrompollutants.,16,OceanPollution,Fig.22-11p.504,17,CaseStudy:ChesapeakeBay,LargestUSestuary,Relativelyshallow,Slow“flushing”actiontoAtlantic,MajorproblemswithdissolvedO2,18,OilSpills,Sources:offshorewells,tankers,pipelinesandstoragetanks,Effects:deathoforganisms,lossofanimalinsulationandbuoyancy,smothering,Significanteconomicimpacts,Mechanicalcleanupmethods:skimmersandblotters,Chemicalcleanupmethods:coagulantsanddispersingagents,19,Solutions:PreventingandReducingSurfaceWaterPollution,NonpointSources,PointSources,Reducerunoff,Bufferzonevegetation,Reducesoilerosion,CleanWaterAct,WaterQualityAct,20,TechnologicalApproach:SepticSystems,Requiresuitablesoilsandmaintenance,21,TechnologicalApproach:Advanced(Tertiary)SewageTreatment,Usesphysicalandchemicalprocesses,Removesnitrateandphosphate,Expensi