太湖地区近百年Hg污染富集特征研究

Enrichment Characteristics of the Past Century Hg Pollution in Taihu Lake Region

通过对太湖梅梁湾沉积物柱样中重金属汞总量的分析测量,并结合210Pb和137Cs计算沉积速率以确定年代,由此探讨了近百年以来Hg的富集特征和Hg的积累过程。结合磁化率与粒度特征,分析其与太湖沉积物中Hg含量的相关关系。结果表明,近百年来太湖沉积物中Hg含量呈持续增长的趋势,但是在20世纪80年代初期以来,沉积物中Hg的含量在逐渐降低,这与流域区域内重度污染工业规模的缩减是息息相关的;磁性矿物含量的增加与重金属污染的输入有关,中值粒径含量与磁化率呈一定的负相关关系,不同粒级的沉积物对于Hg的富集起到不同的作用,其中>32μm的粒级对于Hg的吸附作用随深度的增加而有所加强。

Based on detection of Hg contents of sediment column samples in Meiliang Bay of Taihu Lake and the date determined by calculating deposition rate through^210 Pb and^137Cs method,enrichment characteristics and accumulation process of Hg since centuries were discussed. Combining with the feature of magnetic susceptibility and grain size,the relations of Hg contents of the sediments in the Lake were analyzed. Results showed that Hg contents of sediment in the Lake was in a trend of sustained growth for centuries. However,Hg contents in sediment decreased gradually in the early 1980 s,for reducing the heavily polluted industry scale in the basin area. The increase of contents of the magnetic mineral are associated with the input of heavy metal pollution. The contents of median particle size are negatively related to the susceptibility. The sediments in different grades play a different role for concentrations of Hg,which 〉32 μm size fractions for the adsorption of Hg with increasing depth has been strengthened.