第二松花江水中甲基汞的时空变化规律

为研究第二松花江水中甲基汞的时空变化规律，分别在平水期和丰水期沿二松流域进行了采样分析，得出其空间变化规律：红石、十号线和泔水缸3个断面甲基汞含量较高，在这3个断面两侧甲基汞含量均下降.季节性变化规律：除涝州和四方台断面外，其他各采样断面丰水期甲基汞含量均低于平水期.通过对比分析1981年、 1983年和本研究结果，得出了年际性变化规律：1981年甲基汞含量随与排污口距离的增加而降低；1983年污染源已切断1 a，水中甲基汞含量骤降，达到天然背景值水平，但肇源至四方台江段甲基汞含量均在0.35 ng·L^-1以上；2006年各相应断面甲基汞含量高于1983年，低于1981年.此外，本研究给出了二松水中甲基汞的污染程度.

Temporal and Spatial Variation Rule of Methylmercury in Water in the Second Songhua River

The concentrations of methylmercury (MeHg) in water were investigated in both level period and flood period in the Second Songhua River. The results show that the MeHg concentrations in water of Hongshi, Shihaoxian and Ganshuigang sites are relatively higher than other sampling sites. The MeHg concentrations in the level period are higher than the flood season in most sampling sites beside Laozhou and Sifangtai sites. By comparing the MeHg concentrations in different years, the results reveal that the MeHg concentrations in 1981 decreased with the distances increasing from the sites to the pollution source. The MeHg concentrations in most sites greatly fell in 1983, when the pollution source had been ceased for one year. The concentrations approached the natural background level in most sites, however, they were over 0.35 ng·L^-1 from Zhaoyuan site to Sifangtai site. The MeHg concentrations in corresponding sites in 2006 were higher than that in 1983, but were lower than that in 1981.Moreover, the pollution level in water of the Second Songhua River was also discussed.