基于Donnan渗析离子交换膜分离水中的Cd(Ⅱ)

Separating cadmium(Ⅱ) from water with ion exchange membrane based on Donnan dialysis

基于Donnan渗析原理构建了离子交换膜反应器,探讨了受体池溶液种类和浓度、给体和受体池搅拌功率以及给体池溶液的初始pH、进水流量和Cd(Ⅱ)进水浓度等因素对Cd(Ⅱ)分离效果的影响。结果表明,随着搅拌功率由0.035W增大为0.162 W,Cd(Ⅱ)分离去除率与离子通量显著增加。当受体液NaCl浓度为0～0.5 mol·L-1时,Cd(Ⅱ)分离去除率随着受体液浓度的增加而显著增加。当给体池进水Cd(Ⅱ)溶液初始pH≤8时,Cd(Ⅱ)分离去除率随受体液pH的增加而增加。此外,给体池中Cd(Ⅱ)分离去除率与Cd(Ⅱ)初始浓度以及给体池进水流量成反比。在本实验条件下,Cd(Ⅱ)的分离去除率最高可达85.51%。

In this study,an ion exchange membrane reactor was constructed based on Donnan dialysis.Effects of the receiver phase composition and concentration,stirring power for both receiver and feeding phase,initial pH,feeding rate and initial concentration of Cd(Ⅱ)in feeding solution on the removal of Cd(II)were investigated.The results showed that the Cd(Ⅱ)removal percentage and ion flux increased significantly with increasing the stirring power from 0.035 W to 0.162 W.Within the range of 0~0.5 mol·L-1 for the NaCl concentration of the receiver phase,the separation efficiency of Cd(Ⅱ)increased significantly as the Cd(II)concentration was raised.When the initial pH of the Cd(II)solution is lower than 8,the Cd(Ⅱ)removal was improved as the Cd(II)concentration in the receiver phase increased.In addition,the separation percent of the Cd(II)was inversely proportional to the initial Cd(II)concentration of feeding solution and its feeding rate.Under the experimental conditions,the maximum separation percentage of Cd(Ⅱ)could reach 85.51%.