天然蛭石对金属离子的吸附性能研究  

Adsorption of Metal Ions on Natural Vermiculite

作　　者：刘勇[1] 肖丹[2] 郭灵虹[1] 杨文树[1] 李晖[2] 

机构地区：[1]四川大学分析测试中心,四川成都610064 [2]四川大学化学工程学院,四川成都610065

出　　处：《四川大学学报（工程科学版）》2006年第3期92-96,共5页Journal of Sichuan University (Engineering Science Edition)

基　　金：四川大学青年基金资助项目(0100805505009)

摘　　要：研究了蛭石对单一离子Pb2+、Cd2+、Ni2+、Ag+的吸附特性。其吸附动力学可用拟二级速率方程来描述,计算值与实测值吻合甚好,相关系数达到0.99以上。4种金属离子的吸附速率大小分别为:Ag+>Pb2+>Cd2+>Ni2+。蛭石对4种离子的吸附等温线均符合Langmuir和Freundlich方程,室温下相关系数分别达到0.9以上。且4种金属离子按其吸附容量大小的排列次序为Pb2+>Cd2+>Ag+>Ni2+。进一步研究了混合金属离子在蛭石上的竞争吸附行为。蛭石对4种金属离子的吸附选择性顺序为:Pb2+>Cd2+>Ni2+>Ag+,表明蛭石对Pb2+具有较强的吸附选择性。The kinetics and thermodynamics of Pb^2＋、Cd^2＋、Ni^2＋、Ag^＋ adsorption on a low-cost adsorbent, natural vermiculite, were studied under the condition of pH = 4～5, t = （20±1）℃. Pseudo-second order model was used to describe the reaction rate, and the adsorption capacity calculated by the model was consistent measurement, with the correlation coefficient （r） more than 0.9. The kinetic rote constants for metal ions are in the order of Ag^＋ 〉 Pb^2＋ 〉 Cd^2＋ 〉 Ni^2＋. The adsorption isotherms for metal ion follow both Langmiur and Freundlich isotherm model, with r is more than 0.99. The adsorption capacities for metal ions ate in the order of Pb^2＋ 〉 Cd^2＋ 〉 Ag^＋ 〉 Ni^2＋. Also, the competitive adsorption of four metals adsorbed on vermiculite was studied. The Pb^2＋ is most effectively adsorbed on vermiculite and the selectivity of metal ions adsorbed on vermiculite is in the order of Pb^2＋ 〉 Cd^2＋ 〉 Ni^2＋ 〉 Ag^＋.

关 键 词：蛭石 金属离子 吸附动力学 吸附热力学 

分 类 号：X505[环境科学与工程—环境工程]