冶炼厂渣场周边农田土壤中铜镉的分布特征研究  

Distribution Characterization of Cu and Cd in Surrounding Agricultural Soil of A Waste Dumping Site at A Copper Smelter

作　　者：刘鹏[1,2] 林玉锁[2] 贺静[1,2] 张孝飞[2] 冯艳红[2] 徐建[2] 

机构地区：[1]南京农业大学资源与环境学院,江苏南京210095 [2]环境保护部南京环境科学研究所,江苏南京210042

出　　处：《农业环境科学学报》2009年第7期1397-1403,共7页Journal of Agro-Environment Science

基　　金：公益性行业科研专项项目"土壤环境质量标准制订方法学研究"和"污染土壤风险评估技术方法研究"

摘　　要：通过现场采样及室内测定,调查了某铜冶炼厂的废渣堆放对周边农田土壤的重金属污染状况,分别对调查区土壤中重金属的污染特征、铜和镉的土壤表层富集系数和淋失比率、土壤中重金属可提取态含量及形态进行了研究。结果表明,该调查区土壤中以铜和镉重金属污染为主。镉元素已经较明显地向下迁移,污染深度范围0～40cm,镉在土壤中分布特征与镉易于被水淋溶和在土壤中的形态以交换态为主有关;调查区土壤中的铜主要富集于表层土壤中(0～20cm),这与土壤中的铜不易被水淋溶发生迁移和在土壤中形态主要以非交换态为主有关。由此可见,受重金属污染农田土壤中镉存在较大的环境风险。A site investigation was carried out for surrounding agricultural soil of a waste dumping site at a copper smeher. Heavy metals including As（HMs） were analysized for total 24 soil samples collected. Analysis on characterization of soil contamination, accumulating factor of copper and cadmium in surface soil, leaching loss ratio and extractable concentrations of HMs in soil were performed. The results show that the highest concentrations of Cu and Cd were 1 950 and 88.1 mg·kg^-1 for surface soils, respectively. Cu and Cd were main contaminants from the waste dumping site and caused the contamination of the surrounding soil. An analysis on accumulating factors of HMs indicated that Cu was much easier to accumulate in the surface（0-20 cm） soil than Cal. The calculated leaching loss ratio of Cu and Cd suggest that Cu in surface soil was diffcuh to leach out while Cd was relatively easier to be leached out from surface soil to subsurface（ 20-40 cm and 40-60 cm）soil. A modified Tessier sequential extraction procedure was performed for all the soil samples. The obtained data suggested that 30%-80% of Cu in the soil were present as organic matter bound species, and 1%-20% of Cu in the soil were present as exchangeale species. Comparing with Cu, much higher percentages of Cd （50%-75%） in the soil could present as exchangeable species, which could easily mobilize and transfer to subsurface soil. Our study suggests that Cd in contaminated agricultural soils can pose a potential leaching risk to the environment.

关 键 词：表层富集 淋溶 淋失比率 PH值 

分 类 号：X53[环境科学与工程—环境工程]