The behavior and environmental impact of mercury released through the human activity

对伊德里卡河水和沉积物中汞的化学形态进行了研究。2003年在4个采样点采集淡水样品，2004年在5个采样点采集沉积物样品。水样中总汞含量为4.8~312 ng/L，重组人汞含量为0.77~164 ng/L，汞含量为0.13~66.5 ng/L。从矿场最近的地点采集的样本中记录到的单个物种的最高浓度，其浓度随着距离矿场的距离而下降。河水中甲基汞浓度在0.058-0.588 ng/L之间，最高值出现在矿井下方约1公里处。为了估算底泥汞向水中的释放量，从5个地点采集底泥，用塑料瓶装上河水。这些瓶子在现场装满样本，带回实验室并在室温下储存。5天后，瓶子中覆盖沉积物的水被分离成三部分，即上清层、悬浮层和孔隙水。悬浮层中的水经离心后用于汞的测定。上清液和孔隙水过滤(0.45μm微孔滤膜)，测定溶解的总汞和甲基汞。水体中总汞和甲基汞的浓度分别是淡水的2-119倍和19-1357倍。观测结果表明，河流沉积物可能成为河水中汞的重要来源。为了了解甲基汞和河流中其他汞物种之间的不同行为，需要进行动力学研究。

The chemical forms of mercury in water and sediment in Idrijca river were investigated. Fresh river water and sediment samples were collected from 4 locations in 2003, and 5 locations in 2004.T-Hg, RHg and Hg^0 concentrations in water were 4.8 - 312 ng/l, 0.77 - 164 ng/l and 0.13 - 66.5 ng/l, respectively. The highest concentrations of the individual species were recorded in the sample taken from the nearest point of the mine and their concentrations decreased with distance from the mine. MeHg concentration in river water was 0.058 - 0.588 ng/l and the highest MeHg concentration was observed at a point about 1 km lower leaches of the mine. In order to estimate the release of mercury from sediment into water, sediment was taken from 5 locations with river water in plastic bottles. The bottles were filled with the sample at the sites, brought back to laboratory and stored at room temperature. After 5days, the water overlying sediment in the bottle was separated into three parts, that is, supernatant layer, suspended layer and pore water. Water in suspended layer was used for mercury determination after centrifugation. The supernatant layer and pore water were filtered (0.45 μm Millipore filters) to determine dissolved T-Hg and MeHg. T-Hg and MeHg concentrations in the waters were 2 - 119 times and 19 - 1357 times higher than that in fresh river water, respectively. The observation suggested that the river sediment could become significant source of mercury in river water. To understand the different behavior between MeHg and other mercury species in the river, kinetic investigations will be required.