Mercury speciation and distribution in Aha Reservoir which was contaminated by coal mining activities in Guiyang, Guizhou, China
Mercury speciation and distribution in Aha Reservoir which was contaminated by coal mining activities in Guiyang, Guizhou, China
复制标题
贵州省贵阳市煤矿开采活动污染的阿哈水库汞形态及分布
DOI：
10.1016/j.apgeochem.2010.11.021
复制
发表时间：
2011-02-01
影响因子：
3.4
通讯作者：
Yan, Haiyu
中科院分区：
文献类型：
--
作者：
Feng, Xinbin;Bai, Weiyang;Yan, Haiyu
2005年3月和8月，在中国西南部贵阳市阿哈水库的两个采样点，分别进行了枯水期和丰水期的采样活动，调查了水柱和沉积物中汞形态的分布规律。由于小规模的煤矿开采活动，AHA水库已被汞污染。水和沉积物中的汞浓度都有所上升。水体中溶解汞(DHG)、颗粒汞(PHG)和总汞(THG)浓度有明显的季节变化。这些汞物种在丰水期的浓度显著高于枯水期。径流输入和沉积物中汞的扩散可能是这些汞物种在雨季浓度升高的原因。受污染的沉积物是上覆水中无机汞(IHG)和甲基汞(MeHg)的二次污染源。沉积物中锰的循环控制着DIG向水体的扩散过程。在旱季(冬季和春季)。锰以二氧化锰的形式存在，因为沉积物的最上部处于氧化状态，汞离子被二氧化锰吸收。在雨季(夏秋两季)，由于水体分层，沉积物剖面的最上部处于还原状态，MnO2被还原为Mn2+，这导致随着Mn2+的溶解，Hg2+转化为孔隙水。这导致在雨季，IHG从沉积物向上覆水扩散的Lux更高。两个采样站都显示出一个一致的趋势，即沉积物岩芯最上部的THG浓度下降。这表明为减少ADM对阿哈水库的污染而采取的措施也减少了对该水库的汞输入。从沉积物到上覆水的甲基汞扩散通量在雨季高于枯水期，表明高温有利于沉积物中汞的甲基化过程。(C)2010爱思唯尔有限公司。保留所有权利。
Two sampling campaigns were carried out in March and August 2005 representing dry and wet seasons, respectively, to investigate the distribution patterns of Hg species in the water column and sediment profiles at two sampling stations in Aha Reservoir located in Guiyang, Southwestern China. Aha Reservoir has been contaminated by Hg due to small scale coal mining activities. Mercury concentrations in both water and sediment were elevated. A clearly seasonal variation of dissolved Hg (DHg), particulate Hg (PHg) and total Hg (THg) concentrations in the water column was observed. The concentrations of these Hg species in the wet season were significantly higher than in the dry season. Runoff input and diffusion of Hg from sediments could be the reasons for elevated concentrations of these Hg species in the wet season. The contaminated sediment is acting as a secondary contamination source for both inorganic Hg (IHg) and methylmercury (MeHg) to the overlying water. The cycling of Mn in the sediment governs the diffusion process of Dig to the water column. In the dry season (winter and spring). Mn occurs as MnO2 because the uppermost part of sediment is in an oxic condition and Hg ions are absorbed by MnO2. In the wet season (summer and fall), the uppermost part of the sediment profile is in a reduced condition because of stratification of the water column and MnO2 is reduced to Mn2+, which results in transformation of Hg2+ into porewater as Mn2+ became soluble. This causes a higher diffusive Lux of IHg from sediment to overlying water in the wet season. Both sampling stations showed a consistent trend that THg concentrations decreased in the uppermost part of sediment cores. This demonstrated that the measures taken to reduce ADM contamination to Aha Reservoir also reduced Hg input to the reservoir. Methyl Hg diffusive fluxes from sediment to overlying water were higher in the wet season than the dry season demonstrating that high temperatures favor Hg methylation processes in sediment. (C) 2010 Elsevier Ltd. All rights reserved.