扎龙湿地湖泊表层沉积物重金属污染评价

Assessment of Heavy Metals Pollution in the Surface Sediments of Lakes in Zhalong Wetland

对扎龙湿地湖泊表层沉积物重金属Cu、Zn、Cr、Pb、Cd、Ni、As的含量进行了分析,并采用相关分析和潜在生态危害指数法对其污染状况进行了研究.结果表明,沉积物中重金属含量大小顺序为Zn>Cr>Pb>Ni>Cu>As>Cd.重金属元素含量间存在显著正相关,有机质与Cu、Cr和Cd含量间存在显著正相关,pH与重金属含量的相关性不显著.调查区沉积物质量较好,总体潜在生态风险程度低,各种重金属元素的潜在生态风险顺序为Cd>Pb>As>Cu>Ni>Cr>Zn.Cd在部分采样点存在中等潜在生态风险,应当引起一定的重视.

The contents of heavy metals including Cu, Zn, Cr, Pb, Cd, Ni and As were quantitatively analyzed in the surface sediments of lakes over the wetlands of Zhalong. The characteristics of heavy metals pollution in the surface sediments was studied by the methods of correlation analysis and potential ecological risk index. The results showed that the contents of these heavy metals in the surface sediments followed the descending of Zn 〉 Cr 〉 Pb 〉 Ni 〉 Cu 〉 As 〉 Cd and were significantly correlated with each other, but not significantly correlated with pH. The contents of Cu, Cr and Cd were also significantly correlated with organic matter content in the surface sediments. The heavy metal contents in the surface sediments was lower than the normal level, the potential ecological risk of heavy metals in the surface sediments was generally minor, and was in the descending of Cd 〉 Pb 〉 As 〉 Cu 〉 Ni 〉 Cr 〉 Zn. The potential ecological risk of Cd has a medium potential ecological risk in some of the samplings, and should be paid more attention on it.