呼伦湖沉积物重金属分布特征及生态风险评价

Distribution Features and Ecological Risk Assessment of Heavy Metals in Superficial Sediments of Hulun Lake

采样分析了呼伦湖表层沉积物重金属(Cu、Zn、Pb、Cd、Cr、As、Hg)的含量、分布特征及富集状况,分别以现代工业化前正常颗粒沉积物中重金属含量的最高背景值和我国《土壤环境质量标准》的一级自然背景值为参比值,采用瑞典学者Lars Hakanson的潜在生态危害指数法对呼伦湖沉积物中重金属的富集系数和生态危害系数以及各采样点的生态危害指数进行了评价。结果表明,呼伦湖沉积物中7种重金属的空间变异性较小,其中Zn、Cr、Cu的含量变化具有相同趋势,其他元素的含量分布无明显区域变化;以两种背景值为参比得出的重金属污染水平顺序相近,Cd和As为对呼伦湖生态环境具有潜在影响的主要重金属元素。

The sediments of Hulun Lake were sampled and analyzed in order to get better understanding on the concentration and distribution of heavy metals with respect to their eco-environment risk. The method of potential ecological risk （PER） index presented by Lars Hakanson was applied to analyze the accumulation coefficients, PER coefficients and the PER indexes based on the highest values of heavy metal con- centrations in sediment grain and Grade I values from the ＂National Standard of Soil Environmental Quality＂. The results showed that there was no significant difference in the space concentration distribution for the seven analyzed heavy metals. The concentrations of Zn, Cr and Cu had a similar space changing tendency. The similar sequence of the contamination level was obtained by analyzing the two background values. Cd and As had the most potential impact on the ecological environment.