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ID:32731211
大小:12.85 MB
页数:103页
时间:2019-02-15
《干旱区绿洲灌漠土重金属吸附-解吸机理及其应用研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、cu,Zn,Pb,CdandNiintheirrigateddesertsoilsisnotreversible.(5)Undertheconditionsofcoexistenceoffiveheavymetals,thesalientfeaturesoftheselectivitysequencesforsorptiononthebasisofKdl00wereasfollows:theselectivitysequencesofheavymetalssorptionintheirrigatedsoilswor
2、ePb>Cu>Cd>Zn>Ni;allsoilsamplessorbedagreaterproportionoftotalPbthanofanyothermetal;theKdl00valueofPbwasmorethanfourtimesthatofCuineachsoilsample;theKdl00valueofPbmorethantentimesthatofCuinS60180cIIIsoilsample.,11赡sequencesofaffinityonthebasisofKdl00ofheavymeta
3、lsdesorptionintheirrigatedsoilswerealsoPb>Cu>Cd>Zn>Ni.TheKdl00valueofPbwasmorethanfourtimesthatofCuonthebasisofheavymetalsdesorptionineachsoilsample;theaffmityofPbandCuisfarlargerthanotherheavymetal.(6)Undertheconditionsofcoexistenceoffiveheavymetals,CopperWas
4、distributedmainlyintheorganicfractionintheirrigateddesertsoilsatlowaddedheavymetalsconcentration(25mg/1),exceptforS20-40咖soilsample.Ataddedhigllheavymetalsconcentration(100and200mg/1),mostofCusorbedwereextractedintheircarbonateboundfractionineachsoilsample.For
5、eachsoilsamplesatdifferentaddedheavymetalsconcentrations,zincandleadsorbedworebasicallydistributedmainlyinthecarbonatebound.fractionandFe-Mnoxidesboundfractionintheirrigateddesertsoils;theamountofthecarbonateboundfractionWasgreaterthanthatofFe-Mnoxidesboundfra
6、ctionin.CdsorbedWasdistributedmainlyinthecarbonateboundfractionandexchangeablefractionintheirrigateddesertsoils;inotherwords,Cdaddedhadhihortrendtobetransformedintothecarbonateboundfractionandexchangeablefractionintheirrigateddesertsoils,therefore,itisdifficul
7、ttoeliminateCdpollution.NisorbedWasdistributedmainlyinthecarbonateboundfraction,butaconsiderableportionofNiaddedhadtransformedintotheresidualfractionandexchangeablefraction.(7)Innineextractionprocedures,generally,extractioncapacityofCuWaSasfollow:EDTA>Citricac
8、id>NH4Ac>TCLP>NH4N03>MgCl2~---Tartaricacid>Aceticacid>Oxalicacid;extractioncapacityofNiWasasfollow:TCLP>Citricacid>EDTA>NH4Ac>Tartaricacid>NH4N03=Aceticacid.≈Oxalicacid>MgCl2.n圮cor
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