Arsenic and uranium contamination of Orog Lake in the Valley of Gobi Lakes, Mongolia: Field evidence of conservative accumulation of U in an alkaline, closed-basin lake during evaporation
Arsenic and uranium contamination of Orog Lake in the Valley of Gobi Lakes, Mongolia: Field evidence of conservative accumulation of U in an alkaline, closed-basin lake during evaporation
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DOI：
10.1016/j.jhazmat.2022.129017
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发表时间：
2022-05-04
影响因子：
13.6
通讯作者：
Hasebe, Noriko
中科院分区：
文献类型：
--
作者：
Gankhurel, Baasansuren;Fukushi, Keisuke;Hasebe, Noriko
内陆湖泊、碱性湖泊和咸水湖泊的缩小导致湖水中砷和铀浓度升高。然而，与这些浓缩有关的化学反应仍不清楚。我们进行了为期五年的研究的水化学的Orog湖（蒙古）和沉积物的化学和光谱特征，以确定砷和铀的地球化学行为在蒸发。砷和铀的浓度随着蒸发导致湖水缩小而增加。当湖泊面积最小时，砷和铀的最大浓度分别超过200 μ g/L和600 μ g/L。监测结果与地球化学模拟预测的比较表明，一些砷被删除的湖水在高度干燥的条件下。连续萃取和X射线吸收近边结构分析表明，水铁矿可以吸收As（V）。仅考虑蒸发作用就可以再现铀的积累。在pH > 9时，碳酸盐和水铁矿对铀的亲合力较低，而在pH > 9时，碳酸盐和水铁矿对铀的亲合力较低，
The shrinkage of inland, alkaline, and saline lakes has caused the elevation of arsenic and uranium concentrations in lake water. However, the chemical reactions associated with these enrichments remain unclear. We conducted a five-year study of the water chemistry of Orog Lake (Mongolia) and the chemical and spectroscopic characteristics of the sediment to determine the geochemical behavior of arsenic and uranium during evaporation. The arsenic and uranium concentrations increased as evaporation caused the lake to shrink. The maximum concentrations of arsenic and uranium exceeded 200 mu g/L and 600 mu g/L, respectively, when the lake area was the smallest. Comparisons of the monitoring results with predictions of geochemical modeling suggested that some arsenic was removed from the lake water under highly desiccated conditions. Sequential extraction and X-ray absorption near-edge structure analyses showed that ferrihydrite can take up As(V). The accumulation of uranium could be reproduced by considering only evaporation. The conservative behavior of uranium can be explained by the low affinity of U(VI) for carbonate and ferrihydrite at pH > 9 and high dissolved