磷酸锡晶体去除海水中Pb(Ⅱ)研究  

REMOVAL OF LEAD(Ⅱ) FROM SEAWATER WITH TIN(Ⅳ) ACID PHOSPHATE

作　　者：祝春水[1,2] 王丽萍[1] 柏静[3] 徐少强[2] 吴雪娇[2] 

机构地区：[1]中国矿业大学环境与测绘工程学院,徐州221008 [2]淮海工学院化学工程学院,连云港222005 [3]山东大学环境研究院,济南250100

出　　处：《离子交换与吸附》2011年第5期424-434,共11页Ion Exchange and Adsorption

基　　金：江苏省普通高校研究生科研创新计划项目(CX10B_158Z);江苏省海洋资源开发研究院科技开放基金项目(JSIMR09D03);淮海工学院自然科学基金项目(Z2009017)

摘　　要：利用合成的磷酸锡晶体作为吸附剂，考察了pH值、吸附时间、初始浓度、温度等因素对吸附水溶液中Pb^2＋的影响，同时考察了在模拟海水中的吸附效果。结果表明，磷酸锡对Pb^2＋的吸附量随着pH（3-6）以及吸附时间的增大而增加。吸附动力学过程符合准二级动力学模型。等温吸附数据用Langmuir方程拟合效果最好，20℃时饱和吸附量达到110．50mg/g。Dubinin-Radushkevich（D-R）模型研究表明吸附机理属于化学离子交换。反应机理为磷酸锡中的H^＋与溶液中的Pb^2＋发生了离子交换反应。热力学研究表明磷酸锡对Pb^2＋的吸附是一个自发的、吸热的过程，升温有利于吸附。模拟海水中Pb^2＋的吸附实验结果表明，高盐度对磷酸锡吸附Pb^2＋有一定的不利影响，但幅度不大，可以用于去除养殖海水中的Pb^2＋。所吸附的Pb^2＋可以用HCl解吸，说明磷酸锡具有重复利用的潜能。Tin（Ⅳ） acid phosphate （SnP） was used as adsorbent for the removal of Pb（Ⅱ） from aqueous solutions. The extent of adsorption was investigated as a function of pH, contact time, adsorbate concentration and reaction temperature. The adsorption property of SnP in simulated seawater was also researched. Experimental results showed that the amount of adsorbed lead ions increased with the increase of solution pH in the examined range （3-6） and reaction time. The sorption process followed pseudo-second-order kinetics very well, and the rate constant k2 increased with the increasing temperatures. The equilibrium data followed Langmuir isotherm model well. The maximum sorption capacity amounted to l 10.50mg/g at 20℃. The free energy Es （J/mol） got from the D-R isotherm indicated the sorption process was a chemical ion-exchange mechanism. The ion-exchange reaction was taken place between Pb2＋ and H＋. The negative AGO values and the positive △H^0, △S^0 at various temperatures confirmed the adsorption processes were spontaneous and endothermic. Adsorption experiments conducted in stimulated seawater showed it was feasible for tin（Ⅳ） phosphate in removing Pb^2＋ from hyper-saline media, such as marine culture wastewater. Desorption experiment in the media of HCl solution indicated that the adsorbent can be reclaimed and reused, which enhanced its value in practical appfication.

关 键 词：磷酸锡 海水 铅 离子交换 

分 类 号：X55[环境科学与工程—环境工程]