广西铁山港海域沉积物重金属污染状况及潜在生态风险评价

Assessment on the pollution and potential ecological risk of heavy metals in the surface sediments at Tieshangang Bay,Guangxi

对广西铁山港海域表层沉积物进行采集,对沉积物中重金属(Cu、Pb、Zn、Cd、As、Hg)含量进行测定,并采用单因子指数法和Hakanson潜在生态风险指数法进行了评价。结果表明:6种重金属平均含量(×10-)6依次为Zn(61.1)>Pb(15.9)>Cu(13.1)>As(10.1)>Cd(0.27)>Hg(0.068),均低于国家海洋沉积物一类标准;铁山港表层沉积物重金属单因子污染程度总体较轻,属于低污染水平,污染程度排序为Cu>Zn>Hg>As>Cd>Pb;铁山港海域沉积物重金属潜在生态风险排序为Hg>Cd>As>Cu>Pb>Zn,所有站位潜在生态风险指数RI平均值为63.11,潜在生态风险总体处于较低水平,潜在风险高值区出现在铁山港北部海域,主要受Hg的高潜在风险水平影响。

Based on the investigation data on the contents of heavy metals（Cu,Pb,Zn,Cd,Hg,As） in the surface sediments in Tieshangang Bay,Guangxi,this paper evaluated the integrative pollution effect of heavy metals.Techniques of the single factor index and the potential ecological risk index（RI） were applied to assessing the pollution of these heavy metals（Cu、Pb、Zn、Cd、As、Hg） in the sediments.The results showed that the average concentration of heavy metals was Zn（61.1×10-6）〉Pb（15.9×10-6）〉 Cu（13.1×10-6）〉As（10.1×10-6）〉Cd（0.27×10-6）〉Hg（0.068×10-6）,and all of them were lower than the first class of their concentration regulated in the GB 18668-2002.The single-factor of heavy metals in the surface sediments indicated a lower pollution degree.The order of pollution degree was Cu〉Zn 〉Hg〉As〉Cd〉Pb.The assessment results revealed that the order of potential ecological risk was Hg〉Cd〉As〉Cu〉Pb〉Zn and the average potential ecological risk was 63.11,which indicated that Tieshangang Bay had low potential ecological risk.The northern Tieshangang Bay had a high value,mainly due to the high potential risk of Hg.