电动修复过程中电极逼近对土壤砷迁移与形态转化的影响  

Effect of the approaching electrode on the soil arsenic migration and speciation transformation during electrokinetic remediation

作　　者：曾辉 程凤莲 张学军 吴波[2,3] 郭书海 ZENG Hui;CHENG Fenglian;ZHANG Xuejun;WU Bo;GUO Shuhai(School of Environment and Safety Engineering,Shenyang University of Chemical Technology,Shenyang 110142,China;Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-physicochemical Synergistic Process,Shenyang 110016,China)

机构地区：[1]沈阳化工大学环境与安全工程学院,沈阳110142 [2]中国科学院沈阳应用生态研究所,沈阳110016 [3]污染土壤生物-物化协同修复技术国家地方联合工程实验室,沈阳110016

出　　处：《环境工程学报》2023年第4期1294-1302,共9页Chinese Journal of Environmental Engineering

基　　金：国家重点研发计划项目(2020YFC1806400)。

摘　　要：以高浓度砷污染土壤为修复对象,探究电极逼近法耦合捕集室对砷污染土壤的修复效果。实验设置4个处理,分别为固定电极(FE-EK)、阴极逼近(AC-EK)、阳极逼近(AA-EK)和两极逼近(AAC-EK)。结果表明,AC-EK、AA-EK以及AAC-EK对总砷[As(T)]的迁移具有促进作用,表现为捕集室中As(T)质量分数与初始值相比显著升高(p<0.05),而FE-EK捕集室中As(T)质量分数与初始值相比无显著性差异(p>0.05),As(T)整体迁移率以AAC-EK最高(31.50%),FE-EK最低(15.38%)。由于土壤整体氧化还原电位升高,使得FE-EK、ACEK、AA-EK、AAC-EK处理组三价砷平均质量分数较初始值分别降低9.78%、7.81%、13.65%、4.09%。砷的生物有效性在Fe_(2)O_(3)和电动效应的联合作用下不断降低,表现为可交换态砷、铝结合态砷、钙结合态砷向铁结合态砷、残渣态砷转化。本研究结果表明,AAC-EK促进As(T)迁移的效果最好,可交换态砷占比最低,且单位修复能耗最低,具有良好的砷污染土壤修复潜力。The remediation effect of the approaching electrode technique coupled with a capture chamber was evaluated using soil contaminated with a high concentration of arsenic.Four treatments were set up in the experiment:fixed-electrode electrokinetic(FE-EK),approaching cathode electrokinetic(AC-EK),approaching anode electrokinetic(AA-EK),and approaching anode and cathode electrokinetic(AAC-EK)techniques.The results demonstrated that AC-EK,AA-EK,and AAC-EK techniques promoted the migration of total arsenic[As(T)]:the mass fraction of As(T)in their capture chambers was significantly higher than the initial value(p<0.05),while that in the capture chamber of FE-EK did not differ significantly from the initial value(p>0.05).The overall migration rates of As(T)in AAC-EK was the highest(31.50%),and that in FE-EK was the lowest(15.38%).The average mass fraction of trivalent arsenic in FE-EK,AC-EK,AA-EK,and AACEK techniques decreased by 9.78%,7.81%,13.65%,and 4.09%,respectively,compared with the initial value owing to an increase in the overall soil redox potential.Under the combined influence of Fe_(2)O_(3) and electricinfluence,the bioavailability of arsenic was continuously reduced,as evidenced by the conversion of exchangeable arsenic,aluminum-bound arsenic,and calcium-bound arsenic to iron-bound arsenic and residual arsenic.This study showed that AAC-EK was associated with the highest As(T)migration,lowest proportion of exchangeable arsenic,and lowest energy consumption per unit of remediation.Thus,the AAC-EK technique had good potential for remediating arsenic-contaminated soil.

关 键 词：电动修复 电极逼近 砷污染土壤 砷赋存形态 

分 类 号：X53[环境科学与工程—环境工程]