膨润土对Cu^2＋的吸附及其它金属离子对Cu^2＋的竞争吸附

膨润土对重金属铜的吸附随铜离子浓度的增加先快迭增长而后趋于缓慢最后达成平衡。饱和吸附量为34．10mg·g^-1。Langmuir方程、Freundlich方程和Temkin方程均能拟舍实验结果，但Temkin方程拟合为最佳。pH是影响膨润土对Cu^2＋吸附的主要因素。低pH值不利于膨润土对Cu^2＋的吸附。引入竞争离子，膨润土对Cu^2＋的吸附量明显降低。Ph^2＋、Cd^2＋、Ni^2＋对Cu^2＋的吸附产生不同程度的竞争作用，其竞争力为Pb^2＋〉Cd^2＋〉Ni^2＋。在竞争离子存在的情况下，Cu^2＋的吸附依然遵守等温吸附模型。饱和吸附量从34．10mg·g^-1下降到16．93mg·g^-1（Pb^2＋）、19．21mg·g^-1（Cd^2＋）、26．08mg·g^-1（Ni^2＋）。

Adsorption and Competitive Adsorption of Copper and Other Metal Ion by Bentonite

The adsorption capacity of copper was increase from speediness to slowness, and lastly was no more change with the concentration of copper by bentonite. The saturation adsorption was 34. 10 mg · g^-1. The equilibrium data was fitted to Langmuir, Freundlich and Temkin isotherm, and Temkin isotherm was the best one. The pH was main factor at adsorption of Cu^2＋ by bentonite, and low pH went against adsorption. The adsorption of copper was depressed obviously by the presence of competitive ion in the solution. There was competitive adsorption between Cu^2＋ and Pb^2＋ ,Cd^2＋ .Ni^2＋ . The ranking of competitive power was Pb^2＋〉 Cd^2＋ 〉 Ni^2＋ . Isothermal adsorption model of Cu^2＋ was suited still in the case of mixing with competitive ion. The saturation adsorption was depressed from 34. 10 mg · g^-1 to 16. 93 mg · g^-1 with Pb^2＋ , to 19. 21 mg · g^-1 with Cd^2＋ , to 26.08 mg · g^-1 with Ni^2＋.