水资源可持续发展

SustainableManagementofWaterResourcesinUrbanAreasPerryL.McCartyStanfordUniversityInhaUniversity1978INHAUniversityWorldClassUniversityResearchTeamSustainability–UsingWastewaterasaResource•Water–Industry–Agriculture–DomesticUse•Fertilizingnutrients(N&P)•EnergyOrangeCountyWaterDistrict2008WastewaterReuse(190,000m3/d)Tertiarytreatmentusingmicrofiltration,reverseosmosis,ultraviolet/peroxidetreatmentHistoricalApproachforNutrientRecoveryTraditionalApproachtoEnergyandNutrientRecovery-AnaerobicTreatmenttoMethaneWhatisBestReuseOptionforCapturingAllofWastewater’sResourcePotential?Answer:UseforIrrigation•Irrigationisaconsumptiveuse–besttousewaterforanotherpurposefirst•Irrigationismajorconsumerofwater•Qualityrequirementslessthanfordomesticreuse•Wastewaternutrients(N&P)neednotberemovedthroughenergy-intensiveprocesses–theyareusefulfertilizers•WastewaterenergypotentialcanbesavedthroughanaerobictreatmentanddistributedtreatmentsystemsWaterReuseforAgricultureinMontereyCountyMontereyRegionalWaterPollutionControlAgencyRecoversWater,Energy,andNutrientResources•LargestirrigatedcropwastewaterrecycleinU.S.•Produces76,000m3/dayrecycledwater•Irrigates5,000hectares•Throughanaerobictreatmentandcogeneration,produces50%ofWWTP’senergyneeds•Noenergywastedfornitrogenoxidation–allisusedasplantfertilizerDistributedversusCentralizedTreatment•Centralizedtreatment–Costeffectivefordisposal–Treatedwateroftennotlocatedwhereneeded•Distributed–Betteradaptedforresourcerecovery–Canbelargeorsmallscale–Examples•SanitationDistrictsofLosAngelesCounty•SolaireandDocksideGreenApartmentsSanitationDistrictsofLosAngelesCounty-ReusebySurfaceSpreadingatSatellitePlantsWhittierNarrowsPlant(1962)57,000m3/dSanJosePlant(1971)380,000m3/dSolaire,NewYork,NYFirstGreenApartmentComplexinUSGreenRoof95m3/dayMembraneBioreactorCleaningMembranesTreatmentEnergyRequirementskWh/m3ConventionalAerobicActivatedSludge0.6ConventionalAerobicwithNitrification0.8AerobicMembraneBioreactor1.0ConventionalAerobicwithRO2.5kWh/m3WastewaterOrganics–Potential1.9WastewaterNitrogen–Requiredtoproduce0.8WastewaterEnergyContentWhydon’twecapturemoreofwastewatersenergycontent?Whydoweuseenergytoridwastewatersofnitrogen?kWh/m3WastewaterOrganics–Potential1.9WastewaterNitrogen–Requiredtoproduce0.8WastewaterEnergyContentQuestion•Canwetreatmunicipalwastewateranaerobicallytoachievenetenergyproductionwhilemeetingeffluentqualitystandards?AnaerobicDigestionPrimaryTreatmentAnaerobicSecondaryTreatmentMembraneFiltrationMethaneStrippingCogeneration(CHP)ElectricityHeatCleansedWaterWaste-waterMethaneAirSludgeHeatMcCarty,Bae,Kim,Environ.Science&Tech.,inPress(2011)AssumedDomesticSewageComponentmg/LChemicalOxygenDemand5005-DayBiochemicalOxygenDemand220TotalSuspendedSolids240VolatileSuspendedSolids180TotalNitrogen40TotalPhosphorus8Aerobic/AnaerobicMBRComparisonMethaneProductionNetEnergyProductionMcCarty,Bae,Kim,Environ.Science&Tech.,inPress(2011)WastewaterBiosolidsVolumeComparisonsMcCarty,Bae,Kim,Environ.Science&Tech.,inPress(2011)AnaerobicFluidizedBedReactorCharacteristices•Goodmasstransfer•Lowcloggingpotential•CombineshighSRTwithlowHRT•GoodforlowstrengthwastewatersLidyeChemicalCo.,TaiwanTwo-StageAnaerobicFluidizedBedMembraneBioreactor#Kimetal.,Environ.Science&Tech.,45:576(2011)ReactorsBeingEvaluatedatInhaUniversityAnaerobicFluidizedMembraneBioreactor(AFMBR)InfluentWastewaterReclaimedWaterMembranesFluidizedGACTwo-StageAFBR/AFMBRResults#•InfluentCOD–500mg/L•OverallHRT–5.1hr•OLR–2.4kg/m3-d•CODRemoval–98%•EffluentCOD-10mg/L•EffluentTSS–0mg/L•TotalEnergyRequired–0.06kWh/m3•MethaneEnergyProduced–1.35kWh/m3•Suitableforagriculturalreuse#Kimetal.,Environ.Science&Tech.,45:576(2011)Conclusions•Wastewaterreuseforagricultureandlandscapeirrigationisbestapproachforresourcerecovery•Distributedwastewatertreatmentsystemincreasesopportunityforresourcerecovery•Anaerobictreatmentproducesenergyandreducesbiosolidsproduction•Completeandefficientanaerobictreatmentofdomesticwastewatersnowappearspossible•Theanaerobicmembranebioreactorcanproducehighqualityeffluentforagriculturalusewithoutfurtherposttreatment