黄河三角洲湿地重金属污染生态风险评价

Ecological Risk Assessment of Heavy Metals in the Wetland of the Yellow River Delta

以黄河三角洲湿地为研究区域,分析了湿地表层沉积物中重金属的含量,采用Hakanson潜在生态风险指数法综合评价了黄河三角洲湿地表层沉积物中重金属的污染状况和潜在生态风险程度。结果表明,黄河三角洲湿地表层沉积物中Cu、Pb、Cd、As的均值分别为47. 1、21. 3、1. 44、12. 0 mg/kg,除Pb外,湿地表层沉积物中Cu、Cd、As的含量均高于山东省土壤底质背景值,超出背景值最多的是Cd元素。全区综合潜在生态风险指数RI变化范围为87. 63～1332. 7,均值为540. 24,说明全区具有较高潜在生态风险。4种污染因子污染程度由高到低为Cd> Cu> As> Pb,单个污染物潜在生态危害指数由高到低为Cd> As> Cu> Pb,Cd为黄河三角洲湿地最主要的重金属污染因子和潜在生态风险因子。

In this study,the Yellow River Delta wetland was taken as the study area for analysis of the concentrations of heavy metals in surface sediments.Hakanson’ s potential ecological risk index method was used to comprehensively evaluate the pollution status and potential ecological risk in the surface sediments of the Yellow River Delta wetland.The results indicated that the average contents of Cu,Pb,Cd and As in the surface sediments were 47.1,21.3,1.44,and 12.0 mg/kg respectively.The concentrations of Cu,Cd and As in the surface sediments were higher than the soil background values in Shandong Province, with the element of Cd exceeding maximally.The regional comprehensive ecological risk index of RI varied in the range of 87.63~1332.7 ,with the average value of 540.24,indicating a higher potential ecological risk of the Yellow River Delta wetland.The order of pollution levels of the four pollution factors was Cd〉Cu〉As〉Pb,and the order of potential ecological risk parameters of individual pollutant was Cd〉As〉Cu〉Pb.Element Cd was the major factor of the pollution factors and the potential ecological risk factor in the Yellow River Delta wetland.