茅尾海重金属分布特征及污染评价

Distribution Patterns of Heavy Metals and Pollution Assessments of Maowei Sea

分析了茅尾海海水、表层沉积物和生物体中Cu、Pb、Zn、Cd、Hg的含量及分布特征,并运用单因子指数法、地积累指数法评价了该区重金属污染程度。结果表明:海水中Pb、Cd、Hg的含量大都符合海水水质第一类标准,Cu符合第二类标准,Zn超第二类标准,但含量均低于渔业水质标准;表层沉积物重金属含量符合海洋沉积物质量第一类标准,Cu、Pb、Zn、Cd、Hg的地积累指数(1geo)均较小,Cd污染程度略大,污染多在红树林潮滩,沉积物质量属轻度污染,与国内外海湾相比处于较低污染水平;不同生物对重金属吸附作用存在较大差异,潮间带生物除对Pb外的其他重金属富集效果显著。

The characteristics of spatial distributions of the heavy metals in water, surface sediments and in organism of Maowei Sea in Guangxi were studied. The Index of one single factor and geo-accumula- tion was used to assess heavy metals pollution. The results showed that the average concentration of Pb, Cd, Hg, were lower than the first class water quality standard, Cu did not exceed the second-class water quality standard, Zn exceed the second-class, but was much lower than the fishery water quality standard. The pollution level in surface sediments do not exceed the first-class quality standard of ma- rine sediments, the index of geo-accumulation for Cu, Pb, Zn, Cd, Hg, were lower than 1, the pollu- tion level of Cd was slightly higher, the heavy metal contents of sediments in the wetland and shoals are higher than in the central Maowei Sea, the quality of sediment belonged to the slight pollution, com- pared with the domestic and foreign bays. There were significant differences in the different organisms ＂ sorption on the heavy metals, Cu, and Zn in oyster exceed the third-class marine organisms quality standard, Cu exceed the third-class standard and Hg exceed the second-class standard in Onchidium werrulaturn cuvier, the organisms＇ sorption were very clear except Pb.