可持续发展经济ppt介绍之循环经济讲解environment

1WaterPollutionReference:G.TylerMiller’sLivingintheEnvironment14thEditionPreparedbyShohailMotahirChoudhury2KeyConceptsTypes,sources,andeffectsofwaterpollutantsMajorpollutionproblemsofsurfacewaterMajorpollutionproblemsofgroundwaterReductionandpreventionofwaterpollutionDrinkingwaterquality3Types,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.5SourcesofWaterPollutionPointsourcesNonpointsourcesWaterquality6PointandNonpointSourcesNONPOINTSOURCESUrbanstreetsSuburbandevelopmentWastewatertreatmentplantRuralhomesCroplandFactoryAnimalfeedlotPOINTSOURCES7SourcesofwaterpollutionTheleadingsourcesofwaterpollutionareagriculture,industries,andmining.1.Agriculturalactivitiesaretheleadingcauseofwaterpollutionfromerosion,overgrazing,fertilizersandpesticides,andexcesssaltfromirrigatedsoils.2.Industrialfacilitiesareanotherlargesourceofwaterpollution,andminingisathirdsource.8•Oneofeveryfivepeopleintheworldlacksaccesstosafedrinkingwater.•Ninety-fivepercentofpeopleindevelopedcountriesand74%ofpeopleindevelopingcountrieshaveaccesstocleandrinkingwater.•Inawarmerworld,toomuchrainandtoolittleraincanincreasewaterpollution.9PollutionofFreshwaterStreamsStreamscanrecoverfrommoderatelevelsofdegradablewaterpollutantsiftheflowsarenotreduced.1.Acombinationofdilutionandbiodegradationcanallowrecoveryofstreampollution2.Thebreakdownofpollutantsbybacteriacreatesanoxygensagcurve.Organismsthathaveahighoxygendemandcan’tsurviveinthecurve.3.Volumeofthestream,volumeofwastesentering,flowrate,temperature,andpHlevelsallaffecthowgreatasagcurveisproduced.10OxygenSagCurve11WaterPollution:NowMostdevelopedcountrieshavereducedpointsourcepollution,buttoxicchemicalsandpollutionfromnon-pointsourcesarestillproblems.Streampollutioninmostdevelopingcountriesisaseriousandgrowingproblem.Halfoftheworld’s500majorriversareheavilypolluted,andmostofthemrunthroughdevelopingcountrieswherewastetreatmentisminimalornonexistent.Forexample:Religiousbeliefs,culturaltraditions,poverty,littleeconomicdevelopment,andalargepopulationinteracttocauseseverepollutionoftheGangesRiverinIndia.12PollutionofLakes13TheGreatLakesFig.22-8p.50014GroundwaterPollution:CausesLowflowratesFewbacteriaColdtemperaturesCoalstripminerunoffPumpingwellWastelagoonAccidentalspillsGroundwaterflowConfinedaquiferDischargeLeakagefromfaultycasingHazardouswasteinjectionwellPesticidesGasolinestationBuriedgasolineandsolventtankSewerCesspoolseptictankDe-icingroadsaltWaterpumpingwellLandfillLowoxygen15PollutionofGroundwaterExpertsrategroundwaterpollutionasalow-riskecologicalproblem;itisratedasahigh-riskhealthproblem.TheextentofgroundwatercontaminationisgenerallyunknownPreventionisthemosteffectiveandaffordablewaytoprotectgroundwaterfrompollutants.16OceanPollutionFig.22-11p.50417CaseStudy:ChesapeakeBayLargestUSestuaryRelativelyshallowSlow“flushing”actiontoAtlanticMajorproblemswithdissolvedO218OilSpillsSources:offshorewells,tankers,pipelinesandstoragetanksEffects:deathoforganisms,lossofanimalinsulationandbuoyancy,smotheringSignificanteconomicimpactsMechanicalcleanupmethods:skimmersandblottersChemicalcleanupmethods:coagulantsanddispersingagents19Solutions:PreventingandReducingSurfaceWaterPollutionNonpointSourcesPointSourcesReducerunoffBufferzonevegetationReducesoilerosionCleanWaterActWaterQualityAct20TechnologicalApproach:SepticSystemsRequiresuitablesoilsandmaintenance21TechnologicalApproach:Advanced(Tertiary)SewageTreatmentUsesphysicalandchemicalprocessesRemovesnitrateandphosphateExpensiveNotwidelyused22DrinkingWaterQualitySafeDrinkingWaterActMaximumcontaminantlevels(MCLs)PurificationofurbandrinkingwaterBottledwaterProtectionfromterrorismPurificationofruraldrinkingwater