螯合纤维及离子交换树脂对铜离子吸附动力学性能比较

考察了实验室自制离子螯合纤维和商用D113交换树脂对铜离子的吸附动力学。用Langmuir方程和Freundlich方程拟合吸附等温线,用准一级和准二级动力学方程拟合吸附速率和再生速率实验数据,结果显示螯合纤维及D113树脂对铜离子的吸附等温线符合Langmuir模型,螯合纤维的准一级和准二级吸附速率常数分别是D113树脂的12和30多倍,再生速率常数分别是D113树脂的7倍和6倍。浓度影响实验和中断实验结果显示,螯合纤维对铜离子的吸附速率由膜扩散控制,而D113树脂对铜离子的吸附速率在低浓度(<200mg/L)的时候由膜扩散控制,较高浓度(>300mg/L)时由膜扩散和粒扩散共同控制。

Comparison of Adsorption Kinetics of Copper Ion on Chelating Fiber and Ion Exchange Resin

Adsorption kinetics of copper (II) on the self-made chelating fiber and commercial D113 resin were discussed. The adsorption isotherms were fitted with the Langmuir and Freundlich models and sorption and desorption rate curves were fitted with the pseudo first- and second-order equations. Results showed that the Langmuir model fit the isotherms better than the Freundlich model, and the ratios of the adsorption rate constants for the chelating fiber and D113 resin were 12 and 32, the ratios of the desorption rate constants were 7 and 6 respectively. The concentration effect experiment and interrupt test indicated sorption rate of chelating fiber was controlled by film diffusion, and sorption rate of D113 was controlled by film diffusion at copper concentration lower than 200 mg/L and both by film and particle diffusion at copper concentration higher than 300 mg/L.