鄱阳湖饶河段重金属污染水平与迁移特性

Characteristics of heavy metals contaminant status and migration in Raohe River of Lake Poyang

鄱阳湖饶河入湖段是鄱阳湖重金属污染最严重的水域之一,为了研究其污染现状,本文于2005年3月平水期对鄱阳湖饶河段的水体、底泥、土壤及水生植物的重金属污染水平及迁移特性进行了调查与分析．结果表明,饶河段水体中的重金属除Pb的含量超出地表水环境质量标准Ⅲ类标准外,其它各项监测指标均能达到地表水环境质量Ⅲ类标准．饶河段底泥及河滩土壤的重金属含量平均值与国家土壤环境质量相比,Zn、Cd的平均值超出了三级标准,而Cu、Pb的含量指标均符合三级标准;通过地质积累指数评价结果表明,饶河段重金属底泥除Zn污染为中度污染以外,其他各种重金属污染为轻度污染或偏中度污染,且饶河段底泥中Cu、Zn、Ph三种重金属元素之间呈极显著正相关．饶河段水生植物对Cu、 Zn、Ph都有不同程度的富集;根据富集系数评价表明,植物对Cu的平均富集能力相对较强些,其次是Pb和Zn,多数水生植物表现出对Cd具有一定的抗性．

The Raohe River at the intake of Lake Poyang, is one of the most seriously polluted areas in the Lake Poyang Basin. This paper was based on a survey of heavy metal concentration and migration characteristics in water, sediment, soil, and aquatic plants from this area in March, 2005. The results indicate that the content of the heavy metals Cu, Zn and Cd in the water in the investigated areas meet class Ⅲ criterion for surface water evalution. Pb, however, did not meet this criterion. The average concentration of Zn and Cd in sediment and soil in the sampling sites did not meet class Ⅲ criterion for soil evaluation, but the average sediment and soil concentration of Cu and Pb did meet. The index of geography accumulation results indicate that zinc contamination has reached a moderately advanced stage of pollution, and the other metals such as Cu, Pb, and Cd only superficially pollute the sediment. The three heavy metals Cu, Zn, and Pb in sediment and soil show a positive correlation. Different kinds of aquatic plants in the sampling sites had different enrichment by the different heavy metals Cu, Zn, and Pb. According to the assessment of enrichment coefficient, the average enrichment coefficient of Cu contamination in aquatic plants was relatively higher than Pb and Zn. Most aquatic plants in Raohe River of Lake Poyang resisted contamination by Cd.