胶州湾表层沉积物重金属污染分布特征及其生态风险评价

The distribution characteristics of heavy metals in sediments of Jiaozhou Bay and its potential ecological risk evaluation

根据2009年对胶州湾东岸表层沉积物中重金属调查结果,对重金属含量分布及富集特征进行分析,并采用潜在生态危害指数(RI)法对其生态危害程度进行评价。结果表明,胶州湾东岸表层沉积物中的重金属含量,除7月的Cu、Cr平均含量略低于12月外,其他重金属(Cd、Zn、Pb、As)平均含量7月均高于12月。在表层沉积物中Cd的污染程度最高,7月平均污染指数达1.68。单个重金属潜在生态危害系数(Eir)表明,Cd的Eir大于其他重金属的Eir,其他重金属的Eir均小于轻微危害程度的划分标准,表明对胶州湾东岸生态环境具有潜在影响的重金属主要是Cd,从多个重金属的RI均值看,均小于150,属于轻微生态危害。

The concentration of heavy metals in surface sediments of east coast of Jiaozhou Bay was measured to determine the distribution characteristics and enrichment of heavy metals in Jiaozhou Bay. The potential effect of these heavy metals on local ecological environment was evaluated by the potential ecological risk index. The results showed that the average contents of heavy metals in surface sediments of Jiaodong Bay were larger in July than in December except Cu and Cr. The content of Cd was the highest among all elements in surface sediments and the pollution index of Cd was 1.68; the potential ecological risk factor（E） of heavy metals was lower than the standard of slight ecologi- cal harm except Cd, which indicated that the potential effect factor to ecological environment in this region was Cd. The assessment of potential ecological harm index reveals that the RI values of July and December were lower than 150, which implies those station-located waters have slight ecological harm.