镁铝双金属氢氧化物改性硬硅钙石对铅离子的吸附研究分析 化学工程管理专业VIP免费

镁铝双金属氢氧化物改性硬硅钙石对铅离子的吸附研究摘要：采用水热合成法制备硬硅钙石，再采用水热共沉淀法将Mg(II)、Al(Ⅲ)金属盐在碱性条件下对硬硅钙石进行改性，合成镁铝双金属氢氧化物改性硬硅钙石。将镁铝双金属氢氧化物改性硬硅钙石放置在含Pb2+的模拟废水中进行吸附研究，同时将材料用FT-IR和SEM进行结构表征。结果表明，镁铝双金属氢氧化物改性硬硅钙石对Pb2+溶液初始浓度为300mg/L、吸附剂用量0.04g、40min吸附时间、pH=6.4、T=313.15K条件下，吸附容量727.55mg/g，去除率97.01%。镁铝双金属氢氧化物改性硬硅钙石对铅离子的吸附更符合Freundlish等吸附等温曲线，相关系数都在0.97以上。动力学分析发现，镁铝双金属氢氧化物改性硬硅钙石对铅离子的吸附，既符合准一级动力学方程，又符合准二级动力学方程，相关系数均大于0.99。关键词：镁铝双金属氢氧化物改性硬硅钙石；铅(Ⅱ)；吸附；等温吸附；动力学模型AdsorptionofPb(Ⅱ)inWastewaterbyMagnesiumAluminumDoubleMetalHydroxideModifiedXonotliteAbstract:Xonotlitewerepreparationedbyhydrothermalsynthesismethod.Hydrothermal-coprecipitationmethodwasusedtocombinedifferentbivalentandtrivalentmetalcompounds,suchasAl(NO)3·9H2O,Mg(NO)3·6H2O,xonotlite,toformMagnesiumAluminumDoubleMetalHydroxideModifiedXonotlite(Mg-Al-LDHs-CSH)inalkalineconditions.ThestudycombinedFT-IRandSEMtoanalyszethecrystalstructureandfunctiongroupbeforeandafteradsorptionleadionontheMg-Al-LDHs-CSH.Thismaterialisusedtoadsorbleadionsinwastewaterandtheadsorptionmechanismofmagnesium-aluminumdouble-metalhydroxidemodifiedxonotliteasadsorbentforleadionswasdiscussed.TheexperimentinvestigatedtheeffectsofpH,adsorbentdosage,adsorptiontime,initialconcentrationofleadionsandreactiontemperatureonadsorption.OptimumadsorptionconditionswerefoundtobeinitialpHof6.4,Mg-Al-LDHs-CSHdosageof0.04g,initialPb(II)ionconcentrationof300mg/lat313.15Kandcontacttimeof40min.TheadsorptioncapacityandremovalrateofMg-Al-LDHs-CSHforPb(II)ionswasfoundtobe727.55mg/gand97.01%atoptimumconditions.TheadsorptiondatafromMg-Al-LDHs-CSHexperimentscouldbewelldescribedbythepseudo-second-orderkineticmodelandthefirst--orderkineticmodel.TheadjustedRsquaredforthesecond-orderkineticmodelandthefirst--orderkineticmodelweremorethan0.99.TheLangmuirandFreundlichisothermswerealsostudiedanddatawerebetterfittedwiththeFreundlichisotherm.Keywords:Mg-Al-LDHs-CSH;Adsorption;Pb(Ⅱ);Adsorptionisothermal;Adsorptionkinetics目录1.绪论................................................................................................................11.1含铅水体污染来源、危害及处理方法......................................................11.1.1水体中铅离子污染来源...........................................................................11.1.2铅离子对人类的危害...............................................................................21.1.3含铅离子污染水体处理方法...................................................................21.2硬硅钙石研究现状......................................................................................21.3研究意义......................................................................................................31.4研究内容......................................................................................................32.MgAl-LDHs-CSH的制备及表征...............................................................32.1实验仪器和试剂..........................................................................................32.2硬硅钙石的制备............................