湛江港表层沉积物重金属的分布及其潜在生态风险评价

测定了湛江港12个表层沉积物样品中重金属Cu、Pb、Zn、Cd和Hg的含量,并与有机质含量进行双变量相关分析,同时应用Hakanson潜在生态风险指数法评价了沉积物重金属综合污染效应。结果表明:湛江港海域沉积物中Cu、Pb、Zn、Cd和Hg的含量范围分别为(9.5～27.2)×10-6、(24.4～68.1)×10-6、(15.7～115.2)×10-6、(未检出～0.202)×10-6和(0.026～0.167)×10-6,平均含量分别为17.6×10-6、36.9×10-6、67.0×10-6、0.065×10-6和0.091×10-6。除Pb与Hg之间,各种重金属元素之间均存在显著或极显著的相关关系。除Pb和Cd之外,各种重金属与有机质之间相关系数较高。Hakan-son潜在生态风险评价结果显示,湛江港表层沉积物重金属的潜在生态风险均较小,属轻微生态危害。5种重金属的潜在生态风险大小依次为:Hg>Pb>Cd>Cu>Zn。

Distribution and potential ecological risk evolution of heavy metals in surface sediments of Zhanjiang Harbor

The concentrations of Cu,Pb,Zn,Cd and Hg in 12 surface sediments collected from Zhanjiang Harbor were analyzed.The correlation analysis between heavy metals and total organic material was investigated and the potential ecological risk was assessed based on Hakanson’s potential ecological risk indices.The results showed that the concentration of Cu,Pb,Zn,Cd and Hg were(9.5~27.2)×10-6,(24.4~68.1)×10-6,(15.7~115.2)×10-6,(0~0.202)×10-6,(0.026~0.167)×10-6,and the average concentrations accordingly were 17.6×10-6,36.9×10-6,67.0×10-6,0.065×10-6and 0.091×10-6,respectively.The good positive linear correlations occurred among concentrations of the heavy metals except Pb and Hg.The good positive correlations also occurred between the heavy metals and total organic material except Pb and Cd.The Hakanson’s potential ecological risk indices showed that concentrations of these heavy metals have a low potential ecological risk and have a low probability of being associated with adverse biological effects.The sequence in the degree of their potential ecological risks was:Hg>Pb>Cd>Cu>Zn.