生物可降解螯合剂GLDA强化电动治理镉铅砷复合污染土壤研究  

Enhanced electrokinetic remediation of Cd,Pb,and As compound⁃contaminated soil with GLDA

作　　者：陈春发 王凡 侯建国 冯宏亮 仓龙[2] 泮芝伟 CHEN Chunfa;WANG Fan;HOU Jianguo;FENG Hongliang;CANG Long;PAN Zhiwei(Zhejiang Institute of Geological Prospecting,China Chemical Geology and Mine Bureau,Hangzhou 310002,China;State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China)

机构地区：[1]中化地质矿山总局浙江地质勘查院,杭州310002 [2]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008

出　　处：《安全与环境学报》2024年第1期322-329,共8页Journal of Safety and Environment

基　　金：中化地质矿山总局科技创新项目(ZHTD202105);国家自然科学基金项目(42177032)。

摘　　要：以镉铅砷复合污染土壤为研究对象,将生物可降解络合剂谷氨酸二乙酸四钠[tetrasodium N, N-bis(carboxymethyl)glutamic acid, GLDA]应用于电动治理技术,同时结合投加方式和阴极pH值控制技术,以研究电动治理对土壤中不同重金属的同步去除效率并探讨其去除机制。结果显示:(1)GLDA明显提高了土壤溶液中重金属的质量浓度,有利于土壤重金属在电场作用下移出土体;(2)阳极投加GLDA有利于As的去除,土壤As总去除率可达60.7%,但土壤环境过碱时不利于Cd和Pb的移除;(3)阴极投加GLDA结合pH值控制处理中Cd和Pb的总去除率分别可达35.9%和23.7%,在所有处理中最高,且As的去除率(42.3%)也仅低于阳极投加GLDA处理,是一种较优的同步去除Cd、Pb和As的方法;(4)电动处理后土壤pH值和电导率依处理不同会发生较大变化,总体趋势为阳极附近土壤pH值低于阴极附近,且土壤电导率普遍升高。研究结果为GLDA在重金属复合污染土壤电动治理中的应用提供了理论基础和技术支持。In this study,a biodegradable chelating agent(GLDA,tetrasodium N,N⁃bis(carboxymethyl)glutamic acid)was applied to electrokinetic remediation(EKR)heavy metals contaminated soil by combining the addition position of agents and pH control technology.The simultaneous removal efficiency of different heavy metals in soil by EKR technology was studied and the removal mechanism was discussed.The results showed that GLDA could significantly increase the concentration of heavy metals in soil solution,which was conducive to the migration of heavy metals under the direct current electric field.The addition of GLDA increased the current,and the highest current(0.999 A)was found at 7 d in the treatment combined catholyte addition of GLDA with pH control(T4),which was related to the addition of a large amount of acid to the catholyte for controlling pH.The direction of electroosmotic flow was from anode to cathode except for the T4.The addition of GLDA to the anode(T5)was beneficial to the removal of As,and the removal rate was 60.7%.However,the alkaline soil environment was not conducive to the removal of Cd and Pb.The treatment combined catholyte addition of GLDA with pH control got the highest removal rates of Cd and Pb(35.9%and 23.7%),and the As removal rate(42.3%)was only lower than that of the treatment with anolyte addition of GLDA.So the treatment combined catholyte addition of GLDA with pH control was a better method to remove Cd,Pb and As synchronously.After electrokinetic treatment,soil pH and electrical conductivity changed greatly according to different treatments.The general trend was that the soil pH near the anode was lower than that near the cathode,and the soil electrical conductivity generally increased.This study provides a theoretical basis and technical support for the application of GLDA in the electrokinetic remediation of heavy metal⁃contaminated soils.

关 键 词：环境工程学 电动治理 谷氨酸二乙酸四钠(GLDA) 镉 铅 砷 

分 类 号：X53[环境科学与工程—环境工程]