电动修复法对土壤中镉的去除及形态转化研究

面对镉污染土壤日益严峻的现象以及各种土壤修复技术存在的不足,采用快速、高效、对环境干扰较小的电动修复法对自制镉含量为200 mg/kg的污染土壤进行修复,在不同电压梯度下对土壤p H值、Cd去除效果进行研究,同时采用BCR法分步提取不同形态的镉,对不同形态镉的迁移转化情况进行分析。实验结果表明,随着电压的增加,土壤中不同形态的镉去除效果明显,在靠近阳极区域去除率达到90%以上,在阴极区域以弱酸提取态为主的镉出现了富集现象。另外,酸性条件有利于不同形态的镉向弱酸提取态转化,有利于提高镉的去除率。

Study on Cadmium Removal and Speciation Transformation from Soil by Electrokinetic Remediation

In the face of the increasingly Cd soil pollution and the backward soil remediation technologies ,in this paper the electrokinetic remediation is used for cadmium soil content of 200 mg/kg .Cd removal effect and pH Value are studied under different electric gradients ,meanwhile BCR method is used to extract different forms of Cd and also conduct analysis on the transformation .The result shows ,with the increase of voltage ,Cd removal is obvious and the removal ratio is over 90%close to the the anode in the electrokinetic remediation process .Meanwhile ,enrichment phenomenon occurres in the cathode region and Cd appears mainly in weak acid extraction state .In addition ,different forms of Cd can be easily transformed to the acid extraction state under acidic condition and it will increase the removal ratio of Cd .