鸡蛋膜对水中铜离子的吸附作用

Adsorption of Copper Ion from Water Using Eggshell Membrane

探究鸡蛋膜吸附剂对水中Cu^(2+)的吸附效果,利用二乙氨基二硫代甲酸钠萃取光度法测定溶液中的Cu^(2+)浓度,研究吸附剂粒径,pH,吸附剂用量,吸附温度和吸附时间与Cu^(2+)吸附量之间的关系。结果发现当吸附体系pH值为5,过60目筛鸡蛋膜吸附剂用量为15 g·L^(-1)时,吸附剂对水中Cu^(2+)达到最优吸附效果,吸附量为6.4 mg·g-1;其它共存离子(Pb^(2+),Cd^(2+),Zn^(2+))对Cu^(2+)的吸附影响较小。对等温吸附过程进行测定和模型拟合,发现Langmuir方程拟合效果好,判断鸡蛋膜对水中Cu^(2+)的吸附作用属于单分子层吸附。对吸附过程进行动力学模型拟合,发现Lagergren准二级动力学模型可以很好地描述鸡蛋膜对Cu^(2+)的吸附动力学行为。本研究结果可以为鸡蛋膜在生物传感器和吸附剂方面的应用提供参考。

In order to study the application of eggshell membrane on heavy metal ion adsorption, the effect of eggshell membrane with Cu2 ＋in water was studied from the aspects of size and amount of adsorbent, pH, adsorption temperature and time. It was found that when pH 5 and the amount of adsorbent was 15 g·L^（-1）, eggshell membrane exhibited optimized adsorption on Cu^（2＋）, while the adsorbing capacity was 6.4 mg·g-1; the effect of other co-existing metal ions（Pb^（2＋）, Cd^（2＋）, Zn^（2＋）） have little influence on the adsorption of Cu^（2＋）. Furthermore, models of Langmuir and Freundlich were used to fit the adsorption isotherms. And Langmuir model provided good fitting, which indicates the adsorption between eggshell membrane and Cu2 ＋maybe belong to monolayer adsorption. On the other hands, the adsorption kinetic process was consistent with the Lagergren pseudo-second order kinetic model, which also proves the adsorption belongs to chemical adsorption. This research could provide a reference for application of eggshell membrane adsorbent and chemical sensor.