可生物降解螯合剂亚氨基二琥珀酸和谷氨酸N,N-二乙酸对重金属污染土壤的淋洗修复及动力学特征  

Remediation of Heavy Metal Contaminated Soil by Biodegradable Chelating Agents of IDS and GLDA Washing and Their Washing Kinetics Characteristics

作　　者：陈春乐[1,2] 杨婷 邹县梅 田甜 CHEN Chun-le;YANG Ting;ZOU Xian-mei;TIAN Tian(School of Resources and Chemical Engineering,Sanming University,Sanming 365004,China;Fujian Provincial Key Laboratory of Resources and Environment Monitoring&Sustainable Management and Utilization,Sanming 365004,China)

机构地区：[1]三明学院资源与化工学院,福建三明365004 [2]福建省资源环境监测与可持续经营利用重点实验室,福建三明365004

出　　处：《生态与农村环境学报》2021年第3期394-401,共8页Journal of Ecology and Rural Environment

基　　金：国家自然科学基金(41801279);福建省自然科学基金(2018J05070);三明学院引进高层次人才科研启动经费(16YG02);福建省资源环境监测与可持续经营利用重点实验室开放基金(ZD1803)。

摘　　要：通过振荡淋洗研究了可生物降解螯合剂亚氨基二琥珀酸(IDS)和谷氨酸N,N-二乙酸(GLDA)对污染土壤中重金属Cd、Pb和Zn的淋洗动力学特征,分析了淋洗时间、淋洗剂浓度和pH对土壤重金属淋洗效率的影响,采用BCR连续提取法分析淋洗前后土壤重金属形态变化。结果表明,IDS和GLDA对Cd、Pb和Zn淋洗效率随淋洗时间(5~720 min)延长而增加,Elovich方程和双常数方程适合用于描述淋洗动力学过程,说明该淋洗解吸动力学过程为非均相扩散过程;淋洗剂浓度(0~20 mmol·L^(^(-1)))越大,淋洗效率就越高;随淋洗剂pH(3~10)的上升,淋洗效率呈现先增加后减少的变化。GLDA对Cd和Pb的淋洗去除能力大于IDS,而IDS对Zn的淋洗去除能力大于GLDA。在较佳淋洗条件下(IDS和GLDA浓度为10 mmol·L^(-1),pH为5,分别淋洗240和360 min),IDS和GLDA对Cd淋洗效率分别为21.88%和66.12%,对Pb淋洗效率分别为17.47%和22.96%,对Zn淋洗效率分别为9.21%和8.11%,此时土壤中活性较高的酸溶态和可还原态重金属能够被有效去除。因此,IDS和GLDA淋洗可减少土壤重金属的环境风险。Batch experiments were carried out,to study the washing kinetics characteristics of heavy metals(Cd,Pb and Zn)from a contaminated soil with biodegradable chelating agents of imminodisuccinic acid(IDS)and Dl-2-(2-carboxymethyl)nitrilotriacetic acid(GLDA).The effects of washing time,concentrations and pH value of IDS and GLDA on the heavy metals removal efficiencies were also investigated.Afterwards,fractions of heavy metals in soil before and after washing were determined using the sequential extraction procedure of the optimized European Community Bureau of Reference(BCR).Results show that the removal efficiencies of Cd,Pb and Zn increased with the increasing of washing time(ranging from 5 to 720 min).Both Elovich equation and double-constant equation were suitable for describing the washing kinetic process,which suggested that the desorption of Cd,Pb and Zn from soil as a function of IDS and GLDA was regarded as the heterogeneous diffusion process.The removal efficiencies of Cd,Pb and Zn increased with the increasing of IDS and GLDA concentrations(ranging from 0 to 20 mmol·L^(-1)),however which increased first and then decreased with the increase of the pH of IDS and GLDA solution(ranging from 3 to 10).The removal efficiencies of Cd and Pb with GLDA were greater than that of IDS,while the removal efficiencies of Zn with IDS were better than that of GLDA.Under the optimal washing conditions(10 mmol·L^(-1)IDS and GLDA with pH=5 for 240 and 360 min,respectively),the removal efficiencies of Cd,Pb and Zn by IDS and GLDA were 21.88%and 66.12%,17.47%and 22.96%,and 9.21%and 8.11%,respectively.BCR results demonstrate that the acid soluble and reducible fractions of heavy metals with high activity in soil can be effectively removed by using IDS and GLDA,respectively.Soil environmental risk induced by heavy metals could be reduced after washing with IDS and GLDA.

关 键 词：土壤淋洗 重金属 可生物降解螯合剂 亚氨基二琥珀酸 谷氨酸N N-二乙酸 淋洗动力学 

分 类 号：X53[环境科学与工程—环境工程]