| 湘江株潭长段江水(枯水期）和沉积物中汞的分布和形态 |
| 摘要点击 2077 全文点击 1484 投稿时间：2010-01-02 修订日期：2010-07-17 |
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| 中文关键词 湘江株潭长段 江水 沉积物 汞 分布 形态 |
| 英文关键词 Xiangjiang River section flowing through Zhuzhou, Xiangtan, Changsha river-water sediments mercury distribution species |
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| 中文摘要 |
| 湘江株潭长段江水中（枯水期）的总汞含量为（1.881±1.854）μg·L-1，以颗粒态汞为主.总汞和溶解态汞最大值都出现在霞湾，霞湾—湘潭段衰减快，此后缓慢衰减一直到洞庭湖.沉积物中总汞平均含量为0.846 mg·kg-1，处于高的污染水平，沉积物总汞的最大值也出现在霞湾，达到3.268 mg·kg-1.远远超过国家土壤污染三级标准. 霞湾—马家河段是汞的主要沉积段，总汞含量平均为2.218 mg·kg-1. 易家湾—橘子洲江段沉积物中总汞含量大幅下降，平均为0.442 mg·kg-1.进入长沙段后，汞含量下降缓慢.沉积物孔隙水中汞浓度平均为0.035 μg·L-1，与沉积物总汞没有显著的相关性.沉积物中的汞主要以残渣态、有机结合态、水溶态和可交换态为主，能被重新活化的有机结合态汞含量较高，容易形成再次污染.沿程有机结合态汞比例略有下降，残留态汞比例略有升高，提示有机结合态汞可能部分转为残留态汞.该江段汞沉积层厚约65 cm，沉积层愈靠近顶部，总汞含量愈高.但靠近顶部30～25 cm，总汞含量不再增加. |
| 英文摘要 |
| Total mercury content in water in dry season is（1.881±1.854）μg·L-1 in Xiangjiang River section flowing through Zhuzhou，Xiangtan，Changsha. Mercury in water is mainly in the form of particle mercury. The maxima of total mercury and soluble mercury content discovered in Xiawan attenuating rapidly in section of Xiawan-Xiangtan but slowly in section of Xiangtan-Lake Dongting. The average content of total mercury in sediment is 0.846 mg·kg-1 up to the highest level in rivers of China. The highest content of total mercury discovered in Xiawan is 3.268 mg·kg-1 which far more exceeds Ⅲ-level soil pollution norms of China. In the section of Xiawan-Majiahe mercury mainly exists in sediment and average content total mercury (in sediments) is 2.218 mg·kg-1.With coming down by a big margin total mercury content is 0.442 mg·kg-1 in section of Yijiawan-Juzizhou. In the downstream of Changsha total mercury attenuating slowly. The mercury average content in pore-water of sediments is 0.035 μg·L-1 .There is no significant correlation between pore-water mercury and total mercury. Mercury (in sediments) is mainly in the form of residue，soluble plus exchangeable ions，and organic matter bound that will become active and pollution again. From upstream to downstream the fraction bound to organic matter decreases，but residue mercury increases to a small extent that indicates the change of mercury form from the organic matter bounded to the form of residue. In the section analysis of mercury (in sediments), Hg reaches 65cm deep. As the locations close to sediments top，total mercury content increases until the distance to sediment top is 30-25 cm. |
