Gao Li, Gao Bo, Peng Wenqi, Xu Dongyu, Yin Shuhua
State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China; State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China.
Ecotoxicol Environ Saf. 2018 Jan;147:342-348. doi: 10.1016/j.ecoenv.2017.08.036. Epub 2017 Sep 14.
As the largest man-made reservoir in China, the Three Gorges Reservoir (TGR) has significant influence on national drinking water safety. The geochemical behavior of trace elements at the sediment-water interface (SWI) is still unknown. The mobilization characteristics of trace elements (As, Mo and W)-determined by diffusive gradients in thin films (DGT)-were studied to quantitatively calculate the release trends in the SWI in three typical tributaries and the mainstream of the TGR in the summer. The results showed that concentrations of DGT-labile As, Mo and W in the overlying water and sediment cores showed significant variations in the ranges of 0.05-50.90, 0.30-1.63 and 0.01-0.42μgL, respectively. The apparent net diffusive fluxes were significantly positive in most sampling sites (77.8% for As, 88.8% for Mo and 66.6% for W), suggesting that the sediment was the source of these three elements. It was noteworthy that the maximum net diffusive fluxes of As and W were found in the upstream of Meixi tributary, which may be attributed to anthropogenic activities. In addition, As, Mo and W may be incorporated in Fe and Mn oxyhydroxides and these three elements simultaneously remobilized with Fe and Mn.
作为中国最大的人工水库，三峡水库对国家饮用水安全有着重大影响。沉积物 - 水界面（SWI）处微量元素的地球化学行为仍不为人知。通过薄膜扩散梯度技术（DGT）研究了微量元素（砷、钼和钨）的迁移特性，以定量计算三峡水库三条典型支流及干流夏季沉积物 - 水界面的释放趋势。结果表明，上覆水和沉积物岩心中DGT - 活性砷、钼和钨的浓度分别在0.05 - 50.90、0.30 - 1.63和0.01 - 0.42μg/L范围内呈现出显著变化。在大多数采样点，表观净扩散通量均显著为正（砷为77.8%，钼为88.8%，钨为66.6%），这表明沉积物是这三种元素的来源。值得注意的是，砷和钨的最大净扩散通量出现在梅溪支流上游，这可能归因于人为活动。此外，砷、钼和钨可能被结合在铁和锰的氢氧化物中，并且这三种元素会与铁和锰同时发生再迁移。
