The impacts of organic matter on the distribution and methylation of mercury in a hydroelectric reservoir in Wujiang River, Southwest China
The impacts of organic matter on the distribution and methylation of mercury in a hydroelectric reservoir in Wujiang River, Southwest China
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DOI：
10.1002/etc.3181
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发表时间：
2016-01
影响因子：
4.1
通讯作者：
B. Meng;Xinbin Feng;G. Qiu;Zhonggen Li;H. Yao;L. Shang;Haiyu Yan
中科院分区：
文献类型：
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作者：
B. Meng;Xinbin Feng;G. Qiu;Zhonggen Li;H. Yao;L. Shang;Haiyu Yan
为了解有机质对水电站水库中汞地球化学过程的影响，研究了乌江渡水库沉积物柱样中总汞（THg）和甲基汞（MeHg）在固相和液相中的空间和季节分布特征.从乌江渡水库上游到下游，选取4个不同网箱养殖活动强度的采样点，均匀分布。表层沉积物中甲基汞浓度的升高以及固相和液相中甲基汞的高百分比表明，乌江渡水库下游发生了活跃的汞甲基化过程。相比之下，没有明显的峰值甲基汞在沉积物中从上游的乌江渡水库，符合有机质的低水平，表明甲基汞的生产是有限的。在沉积物中有机质含量高，减少发生在更接近沉积物表面，导致最大的甲基汞浓度在这些层。甲基汞和有机碳之间的相关性意味着，沉积物中的有机质含量来自网箱养殖活动，可以帮助预测甲基汞的生产率在水库，这可以用来评估可能的甲基汞污染的水库生态系统。环境毒理化学2016;35：191-199。© 2015 SETAC
To understand the impacts of organic matter on the geochemical processing of Hg in a hydroelectric reservoir, spatial and seasonal distributions of total mercury (THg) and methylmercury (MeHg) in both solid and liquid phases of sediment cores were investigated in the Wujiangdu Reservoir in Guizhou Province, China. Four sampling sites with different intensities of cage aquaculture activities were chosen and were evenly distributed from upstream to downstream of the Wujiangdu Reservoir. Elevated MeHg concentrations and the high percentage of MeHg in solid and liquid phases of the surface sediment demonstrated that the active Hg methylation process occurred downstream of the Wujiangdu Reservoir. In contrast, the absence of obvious peaks for MeHg in sediment from the upper reaches of the Wujiangdu Reservoir, consistent with low levels of organic matter, suggested that production of MeHg was limited. In sediment with high organic matter content, reduction occurred closer to the sediment surface, resulting in maximum MeHg concentration in these layers. The correlation between MeHg and organic carbon implied that organic matter content in the sediment originating from cage aquaculture activities can help to predict MeHg production rates in reservoirs, which could be used to assess possible MeHg contamination in a reservoir ecosystem. Environ Toxicol Chem 2016;35:191–199. © 2015 SETAC