络合剂对铬污染土壤电动修复作用的影响

用电动方法对铬污染砂土的修复进行了实验室研究。结果表明,EDTA和柠檬酸的加入明显改变了电动过程中电流的大小和铬在砂土中的分配,柠檬酸因与C(rⅥ)发生明显的竞争吸附或与土壤中的C(rⅢ)发生较强的络合作用而增加土壤总铬的迁移率,迁移到阳极附近的铬占砂土中铬含量的78.4%,电动处理以后土壤中剩余的六价铬浓度均显著减少,尤其是加入络合剂后的迁移率比不加入约提高40%,充分表明电动处理时加入络合剂可明显增加对砂土中六价铬的迁移。

Influence of Complexes on Electrokinetic Remediation in Chromium Contaminated Soil

Experimental study was done on electrokinetic remediation of chromium-polluted soil at laboratory scale. The addition of EDTA and citric acid obviously changed the quantity of current and Cr(Ⅵ)distribution in soil during electrokinetic remediation process,in which citric acid increased the mobility of total Cr tremendously in soil by 78.4% due to stronger complexation action of citric acid with Cr(Ⅲ) in soil. Concentrations of all residual Cr(Ⅵ) in soil decreased greatly, especially after adding complex. In comparison with none of adding complexes,the adding of complexes could significantly enhance the mobility by 40%.