城市污水处理技术（英文课件）.ppt

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1、城市污水处理技术（英文课件）Still waters run deep.流静水深流静水深,人静心深人静心深 Where there is life,there is hope。有生命必有希望。有生命必有希望Contents1.Contaminants in Water 2.Contaminant Sources and Treatability 3.Best Available Technologies 4.Trend of Development2 21.Contaminants in Water1.1 Target of Water Quality ControlWastewater Di

2、scharge RegulationKey point:Protection of human health 3 31.2 Capacity of Water EnvironmentAsimplecalculationCi:Concentration of contaminant iMi:Mass of contaminant i in waterV:Water volumeMi0:Mass of contaminant i receivedMir:Mass of contaminant i assimilated(removed)by the water body itself(self p

3、urification)4 41.2 Capacity of Water EnvironmentWaterqualitycriteriaThisisequivalenttoMirisameasureoftheenvironmentalcapacityCis:Standard for contaminant iMis:Maximum permissible mass of contaminant i in water5 51.3 Water Environmental StandardAmerican standard:Clean Water Act(CWA)uAmbient Water Qua

4、lity Criteria for the Protection of Human HealthuAquatic Life CriteriauNutrient Criteria6 61.3 Water Environmental StandardAmerican standard:Clean Water Act(CWA)TheNRWQC 2002includesuCriteriaforprioritytoxicpollutants:120items(15forinorganic,105fororganicpollutants)uCriteriafornonprioritypollutants:

5、45itemsuCriteriafororganoleptic(tasteandodor)effects:23itemsDownloadableathttp:/www.epa.gov/waterscience/criteria/wqcriteria.html7 71.3 Water Environmental StandardChinese standard:EnvironmentalQualityStandardsforSurfaceWater(GB3838-2002)uFundamentalparameters(地表水环境质量标准基本项目标准限值):24itemsuSupplemental

6、parametersforsourcewaterforcommunitywatersupply(集中式生活饮用水地表水源地补充项目标准限值):5itemsuSpecificparametersforsourcewaterforcommunitywatersupply(集中式生活饮用水地表水源地特定项目标准限值):80items8 8表1地表水环境质量标准基本项目标准限值(单位:mg/L)9 9表1地表水环境质量标准基本项目标准限值(单位:mg/L)1010表1地表水环境质量标准基本项目标准限值(单位:mg/L)1111表2集中式生活饮用水地表水源地补充项目标准限值(单位：mg/L)1212表3

7、集中式生活饮用水地表水源地特定项目标准限值(单位：mg/L)1313表3集中式生活饮用水地表水源地特定项目标准限值(单位：mg/L)1414表3集中式生活饮用水地表水源地特定项目标准限值(单位：mg/L)15151.4 Pollutants of Public ConcernIndicative parametersuSuspendedsolids:SSuDissolvedsolids:TDS(salinity)uOrganicsubstances:COD,BOD,TOC,UVuDissolvedoxygen:DOuAcidity:pHNutrientsuNitrogen:TN,NH3-N,N

8、O3-N,NO2-NuPhosphorous:TP,Portho,Ppoly,Poranic16161.4 Pollutants of Public ConcernSynthetic organic chemicals(SOCs)uIndustrialproductssuchasPCBs(Polychlorinatedbiphenyls)uIndustrialbyproductssuchasDioxinuPesticidesandherbicidesDBP precursorsuNaturalorganicmatter(NOM)suchashumicacidsetc.Persistent or

9、ganic pollutants(POPs)uDDT,PCBs,PAHs,Hexachlorobenzene,Dioxins,Furans17171.4 Pollutants of Public ConcernEndocrine disruptive chemicals(EDCs)uHeavymetalssuchasCr,Pbetc.uPCBs,hormones,dioxinsuOrgano-chlorinatedpesticidesMicroorganismsuGiardiauCryptosporidiumuVirusesandbacteria18182.Contaminant Source

10、s and Treatability2.1 Contaminant SourcesPoint sources:Sourcesofpollutantsfromadiscretelocationsuchasapipe,tank,pit,orditch.Non-point sources:Sourceofpollutantsfromanumberofpointsthatarespreadoutanddifficulttoidentifyandcontrol.Non-pointsourcesattributeagreatdealtowaterpollution:lNutrients,pesticide

11、s,NOMlCertainPOPsandEDCs19192.2 Treatability of PollutantsThetreatabilityofpollutantsdependsontheirSizelSuspendedlColloidallSolubleChemical propertieslOrganiclInorganicBiodegradabilitylBiodegradablelBio-non-degradable2020Water quality and treatability matrix2121Domestic wastewater as an exampleMetho

12、dsofpollutantsclassificationuSuspended and soluble:usinga0.45mmfilteruSettleable and non-settleable:plainsettlingfor2hoursuCoagulable and non-coagulable:coagulationandsettlinguSecondary treatment:activatedsludgeprocess(oxidationditch)222223232.3 Limitation of Conventional TreatmentConventional treat

13、mentuTypicalprocessforwatertreatment:CoagulationsedimentationfiltrationchlorinationuTypicalprocessforwastewatertreatment(activatedsludgeprocess):Screeningprimarysettlingbiologicalunitsecondarysettlingchlorination24242.3 Limitation of Conventional TreatmentPollutants that can be removeduSuspendedsoli

14、dsuColloidalmatteruBiodegradableorganicmatteruBacteriaandvirusesPollutants that cannot be removeduMostofthedissolvedsolidsuBio-non-degradableorganicmatteruChlorinepersistentmicroorganisms(e.g.Cryptosporidium)25253.Best Available Technologies3.1 Strategic Considerations on the Selection of Available

15、TechnologiesuConventionaltechnologiesarefundamentaltechnologiesandtheirenhancementshouldbethefirstchoiceuConversionofthepropertyofpollutantsissometimesmoreimportantthanacompleteremovalofthepollutantsuCombinationofdifferenttechnologiesisthekeyforeffectiveremovalofpollutants26263.2 Enhancement of Conv

16、entional TechnologiesEnhanced coagulationuFortheremovalofNOMindrinkingwatertreatmentuFortheenhancementofprimarytreatmentinwastewatertreatmentTakingNOMremovalasanexampleUSEPA Enhanced Coagulation Rule27273.2 Enhancement of Conventional TechnologiesEnhanced coagulationuRequirementsforenhancedcoagulati

17、on:EnhancedcoagulationrequiredasTOC2mg/LuStep1:percentremovalrequirements2828uStep2:0.3/10slope2929upHadjustmentisthekeypoint30303.2 Enhancement of Conventional TechnologiesEnhanced filtrationuForthesafeguardofdrinkingwaterqualityespeciallythecontrolofGiardiaandCryptosporidiumlGiardialamblia:cystsiz

18、e8-12mmx7-10mmlCryptosporidiumparvum:oosystsize4.5-5mmuFortertiarywastewatertreatmenttoacquirehighqualityeffluent31313.2 Enhancement of Conventional TechnologiesEnhanced filtrationuRelationshipbetweenturbidityandparticlesize3232ExampleofturbidityandCryptosporidiumoocystdata33333.2 Enhancement of Con

19、ventional TechnologiesEnhanced filtrationuIronoxide-coatedmediaforNOMsorptionandparticulatefiltrationuIronandaluminumhydroxide-coatedmediafortheremovalofCryptosporidium3434Breakthrough curves for NOM sorption onto coated sand 3535Zeta potential of uncoated sand and sand coated with iron and aluminum

20、 hydroxide3636Improvement of the removal of Cryptosporidium oocysts in sand filters37373.2 Enhancement of Conventional TechnologiesEnhancement of biological processuFluidizedpelletbed(FPB)bioreactorasanexamplethroughacombinationofphysicochemicalprocessandbiologicalprocesslHRTreducedtolessthan1hourlP

21、rimarysettlingandsecondarysettlingomittedlOrganicremovalequivalenttoactivatedsludgeprocesslHighTPremovalachieved3838Flow diagram of the FPB bioreactor3939 Pellets(granule sludge)formed in the bioreactor SEM image of microbes on the surface of the pellets 4040 Distribution of aerobic and anaerobic ba

22、cteria4141 Removal of SS,COD,TP and TN by the bioreactor42423.3 Ozone and Advanced Oxidation ProcessesReactivity of ozone in aqueous solutionInanaqueoussolution,ozonemayactonvariouscompoundsbylDirectreactionwiththemolecularozonelIndirectreactionwiththeradicalspeciesthatareformedwhenozonedecomposesin

23、waterAdvanced oxidationOxidationbyfreeradicalreaction4343Pathways of ozonationPseudo first-order kinetic equation of ozone decomposition4444Ozone decomposition process4545Initiators,promotors,and inhibitors of free-radical reactionsuInitiators:thecompoundscapableofinducingtheformationofasuperoxideio

24、nO2-fromanozonemoleculeuPromotors:allorganicandinorganicmoleculescapableofregeneratingtheO2-superoxideanionfromthehydroxylradicaluInhibitors:compoundscapableofconsumingOHradicalswithoutregeneratingthesuperoxideanionO2-4646Mechanism of ozone decomposition4747Ozone decomposition process by hydroperoxi

25、de ions4848Ozone decomposition process by UV radiation49493.3 Ozone and Advanced Oxidation ProcessesOzonation of synthetic organic chemicalsTwoozonolysispathwaysofozonation:uDirectattackbyelectrophilicordipolarcycloadditionuIndirectattackbyfree radicalsproducedbyreactionwithwaterandwaterconstituents

26、5050Kinetics of ozonation of dissolved organic micropollutantsuOzonationpathwaysuLet5151uTheOHradicalsaregeneratedbyozoneattackonorganicandinorganicinitiators,andthereexistsarelationasuThetotaloxidationrateoftheparticularsubstrateicanbewrittenas5252Characteristics of ozonation of organic compoundsuD

27、ecreaseofaromaticityuUnsaturatedstructuretosaturatedstructureuGenerationofintermediateproductsuTotaldegradationoftenneedsveryhighozonedoseandtakeslongertime5353 Example:Ozonation of aromatic compounds54543.3 Ozone and Advanced Oxidation ProcessesOzonation of natural organic matter(NOM)Aquatichumicsu

28、bstances(AHS):uIsolationmethod:microfiltrationofthewaterandadsorptionoforganicsonXAD-8resinatpH=2,followedbyNaOHelutionandseparationbyprecipitationatpH=1.uTwomaingroups:Humic acidprecipitatedfractionFulvic acidremainingpartinthesolution5555Possible reaction of zone consumption in a natural aquatic e

29、nvironment d inhibitorsi initiatorsp promotorss-scavengers5656Ozone action on AHS5757The effects of ozonation on AHSuFormationofhydroxyl,carbonylandcarboxylgroups;uIncreaseofpolarityandhydrophilicity;uLossofdoublebondsandaromaticity;uShiftinthemolecularweightdistributiontowardlower-molecular-weightc

30、ompounds.5858Py-GC-MS analysis results5959THMs and HPLC analysis results6060Specific UV adsorption(SUVA)as a parameter showing the biodegradability of AHSuTOCorDOC:totalamountoforganiccarbonuUV254:concentrationoforganicswithunsaturatedstructureuSUVA:UV-to-TOCratiowhichrepresentsthefractionofunsatura

31、tedfunctionalgroupsinunitconcentrationoforganicmatteruHighSUVAvalue:lessbiodegradableuLowSUVAvalue:morebiodegradable61613.4 Membrane TechnologiesSpectrum of impurities in water and applicable filtration processes 62623.4 Membrane TechnologiesMembrane operation63633.4 Membrane TechnologiesPressure-dr

32、iven membrane operationuRO:atleasttwicetheosmoticpressuremustbeexerted5to8MPaforseawateruNF:osmoticbackpressuremuchlowerthanROtypically0.5to1.5MPauUF:operatingpressure50to500kPauMF:operatingpressuresimilartoUF64643.4 Membrane TechnologiesPermeation behavioruDarcyslawuToaccountfortheeffectsofosmoticp

33、ressure65653.4 Membrane TechnologiesReduction in Permeate FluxRc:resistanceofconcentrationboundarylayerRcp:resistanceofconcentration-polarizationlayerD:diffusivity66663.4 Membrane TechnologiesReduction in Permeate FluxTheaccumulationofmaterialson,in,andnearamembraneinthepresenceofacrossflowReduction

34、sinpermeatefluxovertime67673.4 Membrane TechnologiesMechanism of membrane foulinguCakeformationuPoreblockageuAdsorptivefoulinguBiofoulingSEMimageofabiofilmformedonamembrane6868Conventional UF or MF process6969Conventional NF or RO process70703.4 Membrane TechnologiesMembrane bioreactor(MBR)uPrincipl

35、eofMBR(a)MBR(b)Membrane for tertiary treatment71713.4 Membrane TechnologiesMembrane bioreactor(MBR)uMBRconfiguration(a)Recirculated MBR(b)Integrated MBR72723.4 Membrane TechnologiesMembrane bioreactor(MBR)uAdvantagesofMBRlGreaterbiomassconcentrationandgreaterloadslHighremovalefficiencylLesssludgepro

36、ductionlGreaterreliabilityandflexibilityofapplicationlAbilitytoabsorbvariationsandfluctuationsintheappliedhydraulicandorganicloadlCompletecontrolofthesludgeagetoallowthedevelopmentofslow-growingmicroorganisms(suchasnitrifyingbacteria)73734.Trend of Development4.1 Integration of Water and Wastewater

37、SystemFundamental considerationsuWatersupplyandwastewatersystemsaresubsystemsintheseriesofurbanmetabolicsystemofwateruWatersupplyaccordingtothepurposesofuseregardingbothquantityandqualityuDesignofwaterandwastewatersystemsasonecomprehensivewatersystem7474Future urban water system with application of

38、membrane technology75754.2 Decentralized Systems for Wastewater Treatment and ReusePhilosophy of decentralizationuNon-mixinglGrey water:Largevolumes,CODdiluted,littlenutrients,pathogens,nopharmaceuticals,personalcareproductslBlack water:Littlevolumes,possibilitiestominimisethemevenfurther,highCODand

39、nutrients,pathogens,pharmaceuticalsandhormonesuSeparatetreatmentlTreatmentdependsontheobjectiveuRecoveryofusefulresourceslWater,energy,fertilizer76764.3 Control of Micropollutants in Water and Wastewater TreatmentuControlofpollutantsourceuUtilizationofhybridprocesslAdvancedoxidationandcarbonadsorptionuUtilizationofhybridmembraneprocesslMembrane-powderedactivatedcarbonreactorlIonexchangemembranereactor7777