植物-电动耦合修复重金属污染土的效能及其强化机制  

Remediation efficiency and strengthening mechanism of heavy metal contaminated soil under phytore-electric coupling treatment

作　　者：李敏 赵博华[1] 于禾苗 齐振霄 李辉 LI Min;ZHAO Bohua;YU Hemiao;QI Zhenxiao;LI Hui(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,P.R.China;Hebei Research Center of Civil Engineering Technology,Hebei University of Technology,Tianjin 300401,P.R.China)

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]河北工业大学河北省土木工程技术研究中心,天津300401

出　　处：《土木与环境工程学报（中英文）》2024年第5期26-37,共12页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(52278341、51978235);河北省自然科学基金(E2018202274);河北省科技创新战略基金(20180602)。

摘　　要：重金属污染土壤的净化效果直接影响修复后土体的再利用。以Cd、Cu、Ni、Zn、Pb污染土壤为研究对象,采用改进环绕式电极布置,以植物-电动耦合修复下土壤的净化度及土壤性质为重点,厘清关键因素,揭示耦合强化修复机制。结果表明:植物-电动耦合修复下不同重金属的去除率均较单一修复有所提高,重金属赋存形态及植物对重金属的响应是影响修复效果的关键因素。改进环绕式电场的施加能积极调动更大范围土壤中的重金属向植物根系迁移聚集,解决了植物修复中重金属可及性和生物活性低的问题;植物修复的协助有利于改善电动修复对土壤性质的不利影响,解决聚焦效应和高能耗问题。植物-电动耦合修复联合了重金属的空间分布改善、重金属生物利用度提升、植物生长代谢强化及土壤微生物生命活动调节等作用机制,有效提高了重金属污染土壤的净化度,修复后土体可维持稳定的pH值(6.27~7.91)、电导率(108~159μs/cm)及低能耗(13.76~18.81 kW·h/m3),有助于推进污染土壤的可持续利用。The purification degree of heavy metal contaminated soil directly affects its reuse.This paper took the soil contaminated with Cd,Cu,Ni,Zn and Pb as the research object,and the improved surround electrode arrangement as the testing method.The purification degree and soil properties of contaminated soil under phytore-electric coupling remediation were used as indicators to examine the key factors and reveal the enhancing mechanism.The results demonstrate that the removal rate of phytore-electric coupling remediation is higher than that of single one,and the occurrence form of heavy metals and the response of plants to heavy metals are the key factors.The method of improved surround electrode arrangement can actively mobilize the migration and then accumulation of heavy metals in a larger range of soil to plant roots,and then solve the problem of low accessibility and biological activity of heavy metals in sole phytoremediation.The assistance of phytoremediation is beneficial to relieve the adverse effects of electrokinetic remediation on soil properties,and solves the problem of concentrating effect and high energy consumption.The coupling remediation combined the improvement of spatial distribution and bioavailability of heavy metals,metabolism of plant,and life activities of soil microbial,which effectively improve the purification of heavy metal contaminated soil.After remediation,the soil can maintain a stable pH of 6.27-7.91,and a conductivity of 108-159 μs/cm.In addition,the energy consumption is only 13.76-18.81 kW·h/m3.The phytore-electric coupling remediation method helps to promote the sustainable use of contaminated soil.

关 键 词：土壤污染 净化修复 植物修复 电动修复 强化机制 重金属污染 

分 类 号：X53[环境科学与工程—环境工程]