重庆市主城区土壤重金属的污染特征 (三峡地区资源环境生态研究)

以重庆市主城区6大功能区即工业区、商业区、交通区、文教区、居民区和旅游区的土壤为对象,根据抽样统计原则,分别采集了48个城市土壤样品,按照国家测量标准方法分析研究了土壤样品的基本性质及重金属(As、Cd、Cr、Cu、Hg、Ni、Pb、Zn等)的全量、模拟酸雨(pH值为4.5)浸出量。结果表明,各功能区土壤的自然组成均无太大的差别,大于0.25 mm的颗粒占有绝对主导地位,各粒径的土壤颗粒对重金属的贡献率与土壤颗粒的自然组成相吻合;重庆市主城区土壤呈碱性,全氮含量远远低于农业土壤,在不同功能区,土壤的全钾含量差异不大,全磷水平不同,有机质含量差异较大;重庆市主城区土壤重金属元素含量有较大的差异,受人为活动干扰严重的重金属为Hg、Cd、Cu和As。内梅罗指数评价结果显示除Cr、Ni外,其他元素均对环境有不同程度的污染,各功能区均受到重金属的严重污染。

Specificity of Heavy Metal Soils in Core Zone of Chongqing

The six functional areas in Chongqing,namely,industrial,commercial,administrative,cultural and educational,residential as well as tourist areas,according to the principles of statistical sampling,separately collected 48 city soil samples.To study the heavy metals contamination of urban soils in core zone of Chongqing,the total contents and extracted heavy metal content by simulated acid rain of As、Cd、Cr、Cu、Hg、Ni、Pb、Zn were analyzed,meanwhile,corresponding properties including pH,organic matter(OM),total nitrogen(TN),total phosphorus(TP) and total potassium(TK) were also analyzed.The results showed that: n different functional zone,the particles larger than 0.25mm were an overwhelming majority of the total soils.The contribution of different size particle to heavy metal content consisted with the natural composing.The urban soils were alkaline,TN were lower than that of agricultural soils.The total heavy metal contents of urban soils in Chongqing had great difference and the elements seriously influenced by people were Cr,Cd,Hg and Cu.The Nemerow comprehensive index indicated that the urban soils were contaminated by six kinds of heavy metals except for Cr and Ni,while all functional zones were polluted seriously.The total heavy metal contents of urban soils in Chongqing had remarkably positive correlation with OM and TP,but had little correlation with pH,TN and TK.