黏粒分离对淋洗法修复Pb污染土壤的影响研究  

Experimental study on the effect of clay particles separation on leaching remediation of Pb contaminated soil

作　　者：张严严 许国辉[1,2,3] 许兴北 任宇鹏 ZHANG Yanyan;XU Guohui;XU Xingbei;REN Yupeng(School of Environment Science and Engineering,Ocean University of China,Qingdao Shandong 266100;Key Laboratory of Marine Environment and Ecology,Ministry of Education,Qingdao Shandong 266100;Shandong Key Laboratory of Marine Environmental Geological Engineering,Qingdao Shandong 266100)

机构地区：[1]中国海洋大学环境科学与工程学院,山东青岛266100 [2]海洋环境与生态教育部重点实验室,山东青岛266100 [3]山东省海洋环境地质工程重点实验室,山东青岛266100

出　　处：《环境污染与防治》2021年第3期317-321,共5页Environmental Pollution & Control

基　　金：国家自然科学基金资助项目(No.41576039)。

摘　　要：根据黏粒含量不同配制4种Pb污染土壤(砂土、砂质黏壤土、壤质黏土、黏土),分析4种污染土壤中不同颗粒组分中Pb分布情况,采用湿筛和虹吸法将土壤中部分黏粒进行分离,通过室内振荡淋洗试验,对比分析黏粒分离前后Pb污染土壤的淋洗效率,计算最优淋洗条件下的药剂成本。试验结果表明,污染土壤中黏粒含量越高,土壤中Pb形态越稳定,越不易被淋洗去除;污染土壤中Pb的分布情况与土壤类型密切相关;随着淋洗剂(乙二胺四乙酸二钠)浓度增加,Pb去除率整体呈现先快速增加后逐渐稳定的趋势,Pb去除率为砂土>砂质黏壤土>壤质黏土>黏土;分离部分黏粒可以降低最优淋洗剂浓度与液固比,使砂土、砂质黏壤土、壤质黏土、黏土淋洗所需药剂成本分别降低25%、52%、83%、87%。Four types of Pb contaminated soil(sand,sandy clay loam,loamy clay and clay)were prepared base on the clay particles content,and the distribution of Pb in different particle components was analyzed.Some clay particles were separated by wet screening and siphoning method,through the indoor leaching test,the Pb leaching removal efficiency of soil before and after clay separation was compared and analyzed,and the chemical cost under the optimal leaching conditions was calculated.The results showed that the Pb contaminated soil with higher clay content had more stable Pb form,which was more difficult to be removed by leaching;the distribution of Pb was closely related to soil type.As the concentration of the leaching agent(Na 2EDTA)increased,the Pb removal rate was increased rapidly and then gradually stable,and Pb removal rate was sand>sandy clay loam>loamy clay>clay.Separating part of the clay particles could reduced the optimal concentration and liquid-solid ratio of the leaching agent,and further reduced the chemical cost for sand,sandy clay loam,loamy clay and clay leaching by 25%,52%,83%and 87%,respectively.

关 键 词：PB污染土壤 淋洗 黏粒 药剂成本 

分 类 号：X53[环境科学与工程—环境工程]