松花江表层沉积物重金属分布特征及风险评价

以2016年9月松花江干流16个采样点表层沉积物为对象,研究重金属Cu、Pb、Zn、Cd、Cr、As的分布特征,采用因子分析法对其污染来源进行解析,采用地积累指数法及潜在生态危害指数法对不同干流段的重金属污染程度和生态风险进行评价。结果表明:松花江干流表层沉积物中6种重金属浓度总和为43.46~311.23 mg/kg,不同干流段6种重金属来源具有一定相似性,均来自工业、农业及生活混合源。嫩江干流和松花江主干流重金属污染程度表现为As>Pb>Cd>Cr>Cu>Zn,二松干流重金属污染程度表现为As>Pb>Cd>Cr=Zn>Cu,不同干流段重金属污染程度均表现为As>Pb>Cd>Cr。在嫩江干流、二松干流和松花江主干流,重金属潜在生态风险均表现为As>Cd>Pb>Cu>Cr>Zn;3个干流的风险指数(RI)分别为46.5~209.2、144.9~221.3和132.4~591.9,分属于低生态风险、中生态风险和中生态风险。

Distribution characteristics and risk assessment of heavy metals in surface sediments of Songhua River

The distribution characteristics of Cu, Pb, Zn, Cd, Cr and As of 16 surface sediment samples from the Songhua River mainstream in September 2016 were studied. The pollution sources were investigated by factor analysis method, and the pollution level and ecological risk of these heavy metals in different river sections were assessed by geo-accumulation index and potential ecological risk index. The results showed that the total concentration of these heavy metals in the sample ranged from 43.46 to 311.23 mg/kg, which originated similarly from the mixed industrial, agricultural and domestic pollution in different mainstream sections. In the Nenjiang River mainstream and the Songhua River mainstream, the pollution level sequence was As>Pb>Cd>Cr>Cu>Zn, and in the Ersong River mainstream, the pollution level was As>Pb>Cd>Cr=Zn>Cu. The pollution level of As>Pb>Cd>Cr was observed in all sampled streams. In the sediments of the Nenjiang River, Ersong River and Songhua River mainstreams, the potential ecological risk sequence was As>Cd>Pb>Cu>Cr>Zn, and the potential ecological risk indexes were 46.5-209.2, 144.9-221.3 and 132.4-591.9 for the three river mainstreams, which means low, middle and middle potential ecological risk respectively.