生物可降解螯合剂PAA/DTPMP对Cd、Pb、Zn复合污染土壤的淋洗修复对比  

Comparison of biodegradable chelating agents PAA/DTPMP for leaching remediation of Cd,Pb and Zn composite contaminated soil

作　　者：李雪 王旭东[1] 张碧荷 郑锦莎 LI Xue;WANG Xudong;ZHANG Bihe;ZHENG Jinsha(School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Shaanxi Key Laboratory of Membrane Separation,Shaanxi Key Laboratory of Environmental Engineering,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,陕西省膜分离重点实验室,陕西省环境工程重点实验室,西安710055

出　　处：《环境工程学报》2024年第12期3642-3651,共10页Chinese Journal of Environmental Engineering

基　　金：陕西省重点科技创新团队计划资助项目(2024RS-CXTD-51);陕西省教育厅服务地方专项资助项目(22JC041)。

摘　　要：针对传统淋洗剂易产生二次污染的问题,选取具备高效、可生物降解、低成本的2种新型环保试剂聚丙烯酸(PAA)、二乙烯三胺五甲叉膦酸(DTPMP),系统考察了2种淋洗剂去除土壤中重金属的能力;探究了淋洗前后土壤形态差异;采用结合强度系数(IR)和迁移指数(MF)计算土壤重金属稳定性和迁移性;并利用潜在生态风险指数对淋洗前后土壤进行了评估。结果表明:在一定程度内,淋洗去除效率随体积分数和接触时间的升高而增长。且酸性条件更有利于Cd、Pb、Zn的去除。综合经济和技术双重因素,选择淋洗最佳固液比为1∶10。相较于PAA淋洗剂,DTPMP显示出更优的处理效果,其在最佳条件下对Cd、Pb、Zn的去除率最高可达84.7%、75.8%、71.1%。此外,PAA和DTPMP淋洗剂减轻了淋洗对土壤化学性质的副作用,且有效降低了土壤重金属迁移率和生物利用度,大大提高了重金属元素稳定性,显著降低了土壤重金属污染潜在风险。Aiming at the problem that traditional leaching agents are prone to secondary pollution,two new environmentally friendly reagents,polyacrylic acid(PAA)and diethylenetriaminepenta-methylenephosphonic acid(DTPMP),which are highly efficient,biodegradable and low-cost,were selected to systematically investigate the ability of the two leaching agents to remove heavy metals from the soil.The differences in the morphology of the soil before and after the leaching were investigated.The stability and mobility of heavy metals in the soil were calculated by using the incorporation strength coefficient(IR)and the mobility factor coefficient(MF).The soil before and after the leaching were evaluated by using the potential ecological risk index.The results showed that within a certain degree,the removal efficiency of drenching grew with the increase of concentration and contact time and the acidic condition was more favorable to the removal of Cd,Pb and Zn.Comprehensive economic and technical factors,the optimal solid-liquid ratio of drenching was selected to be 1∶10.Compared with PAA drenching agent,DTPMP showed superior treatment effect,and its removal rate of Cd,Pb,and Zn was up to 84.7%,75.8%,and 71.1%under the optimal conditions.In addition,PAA and DTPMP leaching agents mitigate leaching side effects on soil chemistry,effectively reduced soil heavy metals mobility and bioavailability,greatly improved heavy metals stability,and significantly reduced the potential risk of soil heavy metals pollution.

关 键 词：土壤淋洗 重金属 生物可降解螯合剂 土壤形态 

分 类 号：X53[环境科学与工程—环境工程]