闽东湿地重金属污染特征与生态风险评价

POLLUTION CHARACTERISTICS AND RISKS OF HEAVY METALS IN THE WETLAND IN EASTERN FUJIAN PROVINCE

调查了闽东红树林湿地沉积物中重金属的含量、分布特征与富集情况,分别以现代工业化前正常颗粒沉积物中重金属含量的最高背景值和福鼎红树林湿地周边环境土壤的平均值为参比值,对红树林沉积物中重金属的富集系数和生态危害系数以及各采样点的生态危害指数进行了探讨,并利用Lars Hankanson潜在生态危害指数法对湿地沉积物中重金属的生态危害进行了评价。结果表明:闽东湿地沉积物中重金属含量均具有一定的区域特征,其中点头镇点头村红树林(4号样点)重金属的平均含量高于其它4个样点;以现代工业化前正常颗粒沉积物中重金属含量的最高背景值为参比值,重金属的富集顺序为Cd>Pb>Cu>Zn,污染水平顺序为Cd>Pb>Cu>Zn;以红树林周边环境土壤的平均值为参比值,重金属的富集顺序为Pb>Cd>Cu>Zn,污染水平顺序为Cd>Pb>Cu>Zn。

In this paper, concentrations, distribution and accumulation of heavy metals in Wetland of Mindong were investigated. The highest values for heavy metals concentrations in sediments before the modem industrialization of the world and the environmental background values of Kandelia can- del Mangrove Wetland of Fuding were used to analyze the accumulation coefficient and potential ecological risk（PER） coefficients for heavy metal. The PER index for each sample location was also discussed. The method for evaluating PER index presented by Lars Hankanson was applied to assess the ecological risk. The distribution of various heavy metal contents revealed the regional distributive characteristics, and the concentrations were higher in the Nod village（ the four sample location） than the others. When the highest values for heavy metals concentrations in sediments before the modem industrialization of the world were taken as references, the accumulating order for these heavy metals was Cd 〉 Pb 〉 Cu 〉 Zn, and the order of pollution level was Cd 〉 Pb 〉 Cu 〉 Zn ; Zn. When the environmental background values of Kandelia candel Mangrove Wetland of Fuding worked as references, the accumulating order was Pb 〉 Cd 〉 Cu 〉 Zn, and the order of pollution level was Cd 〉 Pb 〉 Cu 〉 Zn.