电解液强化电动力修复铅镉污染土壤研究  

Study on remediation of lead and cadmium contaminated soil by electrolyte-enhanced electrokinetic technology

作　　者：章梅 王彦君 周来[2] 张绍楠 何建国 王新富 ZHANG Mei;WANG Yanjun;ZHOU Lai;ZHANG Shaonan;HE Jianguo;WANG Xinfu(Jiangsu Design Institute of Geology for Mineral Resources(Testing Center of China National Administration of Coal Geology),Key Laboratory of Coal Resources and Mineral Resources,China National Administration of Coal Geology,Xuzhou 221006,China;School of Environmental Science and Spatial Informatics,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]江苏地质矿产设计研究院(中国煤炭地质总局检测中心)中国煤炭地质总局煤系矿产资源重点实验室,江苏徐州221006 [2]中国矿业大学环境与测绘学院,江苏徐州221116

出　　处：《能源环境保护》2022年第5期53-59,共7页Energy Environmental Protection

基　　金：徐州市重点研发计划(社会发展)KC20059。

摘　　要：采用电动力修复技术处理铅镉复合污染土壤,考察了乙二胺四乙酸二钠(EDTA)、柠檬酸、柠檬酸+氯化钙等电解液对土壤中Pb、Cd去除效果的影响,探究Pb、Cd在不同电解液条件下的迁移机理。结果表明:当电压梯度为2 V/cm、修复时间为96 h时,分别用EDTA、柠檬酸、柠檬酸+氯化钙作电解液的情况下,Pb去除率分别为14.70%、11.6%、17.01%,Cd去除率分别为22.84%、15.08%、23.3%,消耗的电能分别为29.3、37.8、50.3(kW·h)/g。结合修复后土壤中Pb^(2+)、Cd^(2+)的分布规律及模拟结果可知:EDTA与Pb、Cd络合为PbEDTA^(2-)、CdEDTA^(2-)并向阳极迁移;柠檬酸在酸化土壤的同时,与Pb、Cd络合为PbH_(2)-Citrate^(+)、CdH_(2)-Citrate^(+)、Pb-(Citrate)、Cd-(Citrate)并向两极迁移,在土壤中部出现聚焦现象;在柠檬酸作用的基础上,氯化钙中的Cl^(-)与Pb^(2+)、Cd^(2+)形成PbCl^(+)、CdCl^(+),进一步促进解吸并提高去除率。The technology of electrokinetic remediation was used to treat lead and cadmium composite contaminated soil.The effects of electrolytes such as disodium ethylenediamine tetraacetic acid(EDTA),citric acid and citric acid+calcium chloride on the removal of Pb and Cd were investigated.The migration mechanism of Pb and Cd under different electrolyte conditions was explored.The results showed that the removals(%)of Pb were 14.70%,11.6%and 17.01%,the removals(%)of Cd were 22.84%,15.08%and 23.3%,and the power consumption was 29.3,37.8,and 50.3(kW·h)/g,respectively,with a voltage gradient of 2 V/cm,a remediation time of 96 h and electrolytes of EDTA,citric acid and citric acid+calcium chloride.Combined with the distribution of Pb and Cd in the remediated soil and the simulation results,it was indicated that EDTA migrated to the anode by complexing with Pband Cdinto PbEDTA^(2-) and CdEDTA^(2-).While acidifying the soil,citric acid complexed with Pb^(2+) and Cd^(2+) into PbH-Citrate,CdH-Citrate,Pb-(Citrate)and Cd-(Citrate),migrated to both poles and focused in the middle of the soil.Under the action of citric acid,Clin calcium chloride formed complexes PbCl^(+) and CdCl^(+) with Pb^(2+) and Cd^(2+),further promoting desorption and improving the removal of Pb^(2+) and Cd^(2+).

关 键 词：电动力 铅镉复合污染 土壤修复 机理研究 

分 类 号：X53[环境科学与工程—环境工程]