铅污染农田土壤修复后的环境容量及风险演变  

Soil environmental capacity and risk evolution of a typical Pb-contaminated farmland after remediation

作　　者：周迪 王梅 高学振 温嘉霖 张情亚 陆君 周东美 ZHOU Di;WANG Mei;GAO Xuezhen;WEN Jialin;ZHANG Qingya;LU Jun;ZHOU Dongmei(School of Environmental and Chemical Engineering,Jiangsu University of Science and Technology,Zhenjiang 212100,China;School of the Environment,Nanjing University,Nanjing 210023,China;Jiangsu DDBS Environmental Remediation Co.,Ltd.,Nanjing 210012,China)

机构地区：[1]江苏科技大学环境与化学工程学院,江苏镇江212100 [2]南京大学环境学院,南京210023 [3]江苏大地益源环境修复有限公司,南京210012

出　　处：《农业环境科学学报》2024年第11期2583-2594,共12页Journal of Agro-Environment Science

基　　金：国家重点研发计划项目(2021YFC1809101);国家自然科学基金项目(41907099)。

摘　　要：为探究农田土壤高风险重金属的环境容量及风险演变的时空特征,以我国北方典型铅污染农田为研究对象,采用多种统计学方法综合确定研究区土壤铅的地球化学基线值,并将其作为该农田的土壤环境背景值,以此计算土壤铅的静态环境容量,同时开展为期3 a的铅污染修复过程中的现存环境容量以及生态和健康风险演变特征分析,并对最终修复效果进行评价。结果表明,经过3 a修复,土壤中铅含量超过350 mg·kg^(-1)的点位占比清零,铅土壤现存环境容量由修复前的203.09 kg·hm^(-2)显著增加至修复后的339.57 kg·hm^(-2),且采用原位钝化技术与深翻耕结合的区域环境容量增加最为突出。根据风险评价结果,该农田铅污染潜在生态风险等级已降至低等级,同时健康风险也明显降低,非致癌风险和致癌风险皆在可接受范围内。研究表明,经过3 a修复,该农田的铅环境容量与风险水平均得到显著改善,研究结果可为同样受铅污染农田土壤的修复与安全利用提供一定参考。The spatiotemporal development of soil heavy metal environmental capacity and risk evolution was investigated in a typical leadcontaminated farmland in north China.Various statistical methods were employed to comprehensively determine the geochemical baseline value of soil lead,which was then used as the background value of the farmland to calculate the soil lead static environmental capacity.Besides,the evolution of the existing environmental capacity,ecological/health risk assessments and remediation effectiveness evaluation were conducted during three-year lead remediation.The results showed that after remediation,the proportion of sites with soil lead content exceeding 350 mg·kg^(-1) decreased to zero,and the existing environmental capacity of soil lead significantly increased from 203.09 kg·hm^(-2) to 339.57 kg·hm^(-2),mostly observed in area applied the in situ immobilization combined with deep tillage technology.The risk evaluation results showed that the potential ecological risk of lead contamination in this farmland has been reduced to a low level,and the health risk also significantly decreased,with the non-carcinogenic and carcinogenic risks both within the acceptable range.The study reveals that after three years of remediation,the lead environmental capacity and risk levels of the farmland have significantly improved.The results can provide some references for the remediation and safe utilization of similar lead contaminated agricultural soils.

关 键 词：土壤 铅 环境容量 风险评价 修复 

分 类 号：X53[环境科学与工程—环境工程]