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

研究了伊德里贾卡河水和沉积物中汞的化学形态。2003年和2004年分别在4个地点和5个地点采集了淡水和沉积物样本。水体中T-Hg、RHg和Hg^0浓度分别为4.8 ~ 312 ng/l、0.77 ~ 164 ng/l和0.13 ~ 66.5 ng/l。在离矿山最近的地点采集的样品中记录到的单个物种的浓度最高，并且它们的浓度随着离矿山的距离而降低。河水中MeHg浓度为0.058 ~ 0.588 ng/l，最高浓度出现在矿山浸出点下方约1 km处。为了估计沉积物中汞向水中的释放，从5个有河水的地点提取了装在塑料瓶中的沉积物。这些瓶子在现场装满样品，带回实验室并在室温下保存。5天后，瓶内沉积物上覆水被分离成三部分，即上清层、悬浮层和孔隙水。离心后用悬浮层中的水测定汞。采用0.45 μm Millipore过滤器过滤上清层和孔隙水，测定溶解的T-Hg和MeHg。水体中T-Hg和MeHg浓度分别是淡水的2 ~ 119倍和19 ~ 1357倍。结果表明，河流沉积物可能成为河流中汞的重要来源。为了了解甲基汞和其他汞在河流中的不同行为，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.