Department of Environment and Civil Engineering, Jiangnan University, Wuxi, China.
Environ Sci Pollut Res Int. 2014 Feb;21(4):3126-33. doi: 10.1007/s11356-013-2274-9. Epub 2013 Nov 8.
Optimizing process parameters that affect the remediation time and power consumption can improve the treatment efficiency of the electrokinetic remediation as well as determine the cost of a remediation action. Lab-scale electrokinetic remediation of Pb-contaminated soils was investigated for the effect of complexant ethylenediaminetetraacetic acid (EDTA) and acetic acid and approaching anode on the removal efficiency of Pb. When EDTA was added to the catholyte, EDTA dissolved insoluble Pb in soils to form soluble Pb-EDTA complexes, increasing Pb mobility and accordingly removal efficiency. The removal efficiency was enhanced from 47.8 to 61.5 % when the EDTA concentration was increased from 0.1 to 0.2 M, showing that EDTA played an important role in remediation. And the migration rate of Pb was increased to 72.3 % when both EDTA and acetic acid were used in the catholyte. The "approaching anode electrokinetic remediation" process in the presence of both EDTA and acetic acid had a higher Pb-removal efficiency with an average efficiency of 83.8 %. The efficiency of electrokinetic remediation was closely related to Pb speciation. Exchangeable and carbonate-bounded Pb were likely the forms which could be removed. All results indicate that the approaching anode method in the presence of EDTA and acetic acid is an advisable choice for electrokinetic remediation of Pb-contaminated soil.
优化影响修复时间和能耗的工艺参数可以提高电动修复的处理效率，并确定修复措施的成本。本研究采用实验室规模的电动修复方法，研究了络合剂乙二胺四乙酸（EDTA）和乙酸以及接近阳极对 Pb 去除效率的影响。当 EDTA 添加到阴极电解液中时，EDTA 将土壤中不溶性 Pb 溶解形成可溶性 Pb-EDTA 配合物，从而增加 Pb 的迁移率，进而提高去除效率。当 EDTA 浓度从 0.1 M 增加到 0.2 M 时，去除效率从 47.8%提高到 61.5%，表明 EDTA 在修复中起着重要作用。当阴极电解液中同时使用 EDTA 和乙酸时，Pb 的迁移率增加到 72.3%。在 EDTA 和乙酸存在下的“接近阳极电动修复”过程具有更高的 Pb 去除效率，平均效率为 83.8%。电动修复的效率与 Pb 的形态密切相关。可能被去除的是可交换态和碳酸盐结合态 Pb。所有结果均表明，在 EDTA 和乙酸存在下采用接近阳极方法是电动修复 Pb 污染土壤的一种可行选择。
