黄浦江水源地水和沉积物中汞的分布

分析黄浦江水源地干流及上游支流水和沉积物中汞含量的分布特征得知，干流沉积物比较清洁，而水中汞含量普遍超标，尤其是松浦大桥取水口水质存在安全隐患，其水样汞含量超过国家Ⅱ类地表水标准(0.05 μg/L)1.40倍. 支流水环境质量恶劣，沉积物中汞含量普遍严重超标，最高值可达到环境背景值(101.20 μg/kg)的4.12倍；支流水体高强度的汞输入是导致干流水质汞超标的直接原因. 采用主成分分析和相关分析，探讨沉积物粒度和有机碳含量以及水体pH对水和沉积物中汞含量变化的影响，指出汞在水-沉积物界面的分配受生物地球化学过程和水动力作用的影响和控制. 结合实地考察，判定农村地区生活垃圾不当处置、燃煤以及化肥和农药的施用是水源地汞的主要来源. 

The Distribution of Mercury in the Water and Sediment at Huangpu River Water Source Area

Based on statistics analysis on concentration of Hg in water and sediment samples, spatial distribution characteristic of Hg in the Huangpu River can be concluded. The Hg concentration in mainstream sediment is still low, but the dissolved Hg concentration in surface water of mainstream is comparatively high especially at the drinking water exploiting spot at Songpu Bridge, with dissolved Hg concentration exceeding Classification Ⅱ of national surface water standard by 140%. The water quality of tributaries is severely high, and the Hg concentration in the sediment generally exceeds the standard value, with the highest more than 4.12 times of the environment background. The high Hg concentration in the water of mainstream is directly due to the high-intensity input from the tributaries. By means of Principal Components Analysis and Correlation Analysis, the environmental factors, such as organic carbon content, average granularity of sediment and pH of surface water, affecting Hg concentration variation were explored, suggesting that the distribution and transition of mercury at water-sediment interface should be under control of biogeochemical evolvement and hydrodynamic disturbance. According to investigation on the spot, improper garbage disposal, coal burning, and application of fertilizer and pesticide in the countryside werejudged as the main Hg origins in the water source area.