杭州和睦湿地表层沉积物重金属时空分布特征及污染评价

The Spatial and Temporal Distribution and Pollution Assessment of Heavy Metals in the Surface Sediments of Hemu Wetland in Hangzhou

分析了杭州市和睦湿地表层沉积物重金属含量及分布特征,并运用污染指数法和Hakanson潜在生态风险指数法对和睦湿地沉积物重金属进行了污染评价和生态风险评价.结果表明:空间分布上和睦湿地沉积物重金属以高Zn、高Ni含量和高Cu、Cr含量为主要特征;季节分布特征上以7月和1月的高Cu、Zn、Cr、Ni含量为主要特征;单项污染指数表明,和睦湿地沉积物中Cu、Zn、Cr、Ni在不同季节呈现一定的中、轻度单项污染,且以7月和1月的污染更甚,故应关注和睦湿地不同样点沉积物中Cu、Zn、Cr、Ni的季节性污染防控工作;综合污染指数评价表明,各样点在不同季节呈现中、轻度综合污染.Hakanson潜在综合生态风险评价指数(RI)表明,和睦湿地沉积物重金属的生态风险水平均达轻微风险等级,Hakanson潜在单项生态风险评价指数(Er)则表明,和睦湿地沉积物中主要的潜在生态风险因子为Cu与Cr,故应重视和睦湿地沉积物重金属中Cu、Cr的潜在生态风险评价及管理.

This paper analyzed the content and seasonal distribution characteristics of heavy metals in the surface sediments of Hemu wetland ,Hangzhou ,and evaluated the pollution and ecological risk of these heavy metals by pollution index method and Hakanson potential ecological risk index method .The results show the enrichment of Zn ,Ni ,Cu and Cr in the surface sediments ,especially much higher in July and January .The single pollution index indicates the high content of Cu ,Zn ,Cr and Ni in the surface sediments presents moderate or mild single pollution in different seasons and the highest pollution level is in July and January ,which suggests the seasonal pollution prevention and control of Cu ,Zn ,Cr and Ni in the surface sediments of Hemu wetland needs to be paid more attention . The comprehensive pollution index evaluation reveals that each sample point presents moderate or mild comprehensive pollution in different seasons .Hakanson potential comprehensive ecological risk index （RI） evaluation shows that the ecological risk level of heavy metals in the surface sediments of Hemu wetland mostly reaches the slight risk rank . However , Hakanson potential individual ecological risk index （Er） indicates that the main potential ecological risk factors are Cu and Cr in the surface sediments of Hemu wetland , hence ,the potential ecological risk assessment and management of Cu and Cr should be strenghened .