water pollutants and their sources(水污染及污染源)

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1、Ppt1HereI’dshowthewaterpollutantsandtheirsources.Ppt2Thewiderangeofpollutantsdischargedtosurfacewaterscanbegroupedintobroadclasses,asshowninTable.Domesticsewageandindustrialwastesarecalledpointsources.Urbanandagriculturalrunoffarecallednon-pointsources.[də'mestɪk]['su：ɪdʒ]生活污

2、水城市和农业径流Ppt3HereIlistsomecontaminants[kən'tæminənt]TheOxygen-demandingmaterial需氧物质Nutrients['nju:triənt]营养物质PathogensOrganisms['pæθədʒəns]病原微生物Suspendedsolidsorsediments['sɛdəmənt]沉积物SaltsToxicmetals['tɒksɪk]有毒金属Andwewilldiscussthemlater.Ppt4PointsourcesFirstthepointsources.D

3、omesticsewageandindustrialwastesarecalledpointsourcesbecausetheyaregenerallycollectedbyanetworkofpipesorchannelsandconveyedtoasinglepointofdischargeintothereceivingwater.Asisshowninthepicture.Channels['tʃænlz]通道，水槽Domesticsewageconsistsofwastesfromhomes,schools,officebuilding

4、s,andstores.Thetermmunicipalsewageisusedtomeandomesticsewageintowhichindustrialwastesarealsodischarged.municipalsewage[mjʊ'nɪsɪp(ə)l]城市污水Ingeneral,pointsourcepollutioncanbereducedoreliminatedthroughwasteminimizationandproperwastewatertreatmentpriortodischargetoanaturalwaterbo

5、dy.eliminated[ɪ'lɪmɪnetɪd]消除minimization[,mɪnɪmɪ'zeʃən]最小Prior['praɪə]在前　UndertheFederalWaterPollutionControlActof1972someanimalfeedingoperations(AFOs)maybedesignatedasapointsource.　AFOsaredesignatedpointsourcesifthefeedingoperationmaybeclassifiedasaconcentratedanimalfeedingo

6、peration(CAFO).AFOs　isanorganophosphoruspesticidesFedaral联邦AFOs灭蚜磷Designated['dɛzɪg,netɪd]指定的organophosphorus[,ɔːg(ə)nəʊ'fɒsf(ə)rəs]有机磷pesticides['pestɪsaɪdz]杀虫剂Ppt5Non-pointsourcesUrbanandagriculturalrunoffarecharacterizedbymultipledischargepoints.Thesearecallednon-pointsour

7、ces.['mʌltɪpl]多个城市和农业径流具有多个放电点。Oftenthepollutedwaterflowsoverthesurfaceofthelandoralongnaturaldrainagechannelstothenearestwaterbody.Evenwhenurbanoragriculturalrunoffwatersarecollectedinpipesorchannels,theyaregenerallytransportedtheshortestpossibledistancefordischarge,sothatwa

8、stewatertreatmentateachoutletisnoteconomicallyfeasible.drainagechann