沱江流域水系沉积物重金属的潜在生态风险评价  

Evaluation on potential ecological risk of heavy metals pollution in sediments from Tuojiang drainage

作　　者：李佳宣[1] 施泽明[1,2] 郑林[1] 倪师军[1,2] 

机构地区：[1]成都理工大学地球化学系,成都610059 [2]地学核技术四川省重点实验室,成都610059

出　　处：《地球与环境》2010年第4期481-487,共7页Earth and Environment

基　　金：国家环保部"汶川特大地震造成矿山破坏对农田土壤污染评估与应对措施";中国地质调查局"成都经济区城市生态地球化学调查与评价"(200314200015)

摘　　要：通过对沱江流域水系沉积物的系统研究,查明了重金属元素含量的空间分布特征,进行了潜在生态风险质量评价。研究结果显示,在两支流交汇之前,沉积物中重金属的污染水平从上游到下游呈上升趋势,矿业活动是水环境中重金属的主要来源,两支流交汇之后元素含量有较明显升高,显示两河汇流叠加对沱江下游水系沉积物有较大的影响;与前人研究相比,各元素含量有较明显的增加;沱江水系沉积物中重金属的潜在生态风险水平较低,大多属于轻微生态风险,Cd的潜在生态危害程度最严重;多种重金属的潜在生态风险指数(R1)表明河流重金属污染属于轻微生态危害,其受危害程度由大到小的顺序为:沱江>石亭江>绵远河。By systematic study on sediments from Tuojiang rivers, the content of heavy metals in the sediments were determined and their distribution characteristics were studied.The potential ecological risk of heavy metals were analyzed and assessed by using the method of potential ecological risk indices presented by Hakanson. The results show that before two tributaries converged, the pollution levels of heavy metals increase from upper to downstream of Tuojiang River implicated that mining activities were the most important source for heavy metals in Tuojiang River. After two tributaries converging, the contents of heavy metals increase obviously, which shows that additive effects of two rivers have greater impacts on the downstream of Tuojiang River. Compared with previous studies, the content of heavy metals have great increased. Potential ecological risk of heavy metals in sediments from Tuojiang River was low-grade, with low ecological risk values at the most points. The potential ecological risk of Cd was the highest. The contamination levels of sediments are light; Tuojiang River is more serious than Shitingjiang River and Mianyuanhe River.

关 键 词：水系沉积物 重金属 潜在生态风险评价 沱江流域 

分 类 号：X82[环境科学与工程—环境工程]