从土壤中去除Cu^(2+)的电修复过程

REMOVAL OF Cu^(2+) FROM CLAY BY ELECTROREMEDIATION

建立了土壤电修复实验装置 ,以Cu2 + 为模拟污染物 ,研究了缓冲溶液组成对Cu2 + 在土壤中的吸附及解吸过程的影响 ;考察了土壤粒径、清洗液组成等对土壤颗粒 ζ -电位及土壤填充床电渗流量的影响 ;以柠檬酸为清洗液 ,在适宜的操作条件下 ,土壤中Cu2 + 的去除率可达 89.9% ,所消耗的清洗液仅为被修复土壤的质量的1.33倍 ;设备放大实验结果表明 ,当采用恒电流操作模式时 ,在相同的电流密度下 ,不同规模电渗装置的清洗率一致 ,未出现“放大效应” 。

Removal of Cu2+ from clay by electroremediatioln was carried out in a multicompartment apparatus. The batch adsorption and desorption of Cu2+ on clay were firstly studied against buffer composition in terms of pH and electroconductivity. Then effects of particle diameter, washing buffer composition on the magnitude of ζ-potential of clay and on the specific electroosmosis velocity of the clay bed were examined, respectively. In case of using citric acid buffer as the washing solution, 89.9% of the Cu2+ absorbed on clay could be recovered at the expense of the buffer 1.33 times as much as the clay weight. Finally, scaling-up of the apparatus in terms of the expansion of cross area was attempted. An approximate recovery of Cu2+ was obtained for the packed beds of different cross area operated at an identical current density, indicating a high potential of this technique in large scale soil remediation.