沈阳沈抚灌区上游土壤重金属镉和铬的现状及潜在生态风险评价

为调查沈抚灌区停灌10多年土壤环境质量状况,在沈阳沈抚灌区上游10个行政村布设了50个取样点,分析测定了土壤重金属镉和铬的含量,并对其进行评价.分析结果表明,有4个行政村土壤重金属镉和3个行政村土壤重金属铬超出辽宁省土壤环境背景值标准,但均未超出国家二级标准,说明沈抚灌区灌溉没有给采样区域土壤带来重金属镉和铬污染,但已有重金属富集.土壤重金属镉和铬变异系数在10%～100%之间,说明土壤扰动性较大.按照辽宁省土壤环境背景值标准进行单项污染指数和内梅罗综合污染指数以及潜在生态风险评价表明:重金属镉具有污染风险,存在着一定的生态风险.重金属铬一般无污染风险,生态风险较小.

Present Situation and Potential Ecological Risk Assessment of Heavy Metal (Cd, Cr) in Soil in Upriver Range of Shenyang-Fushun Irrigation Area

To investigate environmental quality without 10-years irrigation on soil, more than 50 sampling points were set in the upriver range of the Shenyang-Fushun irrigation area and contents of the Cd, Cr in soil are analyzed and assessed. The results of the analysis show that there were 4 and 3 administrative villages which Cd, Cr content in soil exceeded the soil environmental background values standard in Liaoning province, but were not beyond the national second-level standards. The results show that the irrigation in Shenyang-Fushun irrigation area did not bring heavy metal contamination of Cd and Cr to the sampling area, but there has the accumulation of heavy metals.. Heavy metal variability in range of 10%-100% shows that there is a intensive disarrangement on soil. According to assessment of the single pollution index, the Nemerow integrated pollution index and the evaluation of the potential ecological risk, the results shows that Cd content was under moderate pollution level and the heavy metal Cr content was under light pollution level; Cd could lead a certain ecological risk, while the ecological risk of heavy metal Cr was relatively small.