Distribution of mercury and methylmercury in river water and sediment of typical manganese mining area  

作　　者：Yongjiang Zhang Tao Sun Ming Ma Xun Wang Qing Xie Cheng Zhang Yongmin Wang Dingyong Wang 

机构地区：[1]College of Resources and Environment,Southwest University,Chongqing 400715,China [2]Department of Environment and Quality Test,Chongqing Chemical Industry Vocational College,Chongqing 401220,China [3]School of Agricultural Sciences,Zhengzhou University,Zhengzhou 450001,China

出　　处：《Journal of Environmental Sciences》2022年第9期11-22,共12页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 41877384 );the Science and Technology Research Program of Chongqing Municipal Education Commission (No. KJQN202104501 )。

摘　　要：Manganese(Mn) ores contain substantial concentrations of mercury(Hg), and mining and smelting of Mn ores can bring Hg into the surrounding aquatic environment through atmospheric deposition, leaching of electrolytic Mn residue and Mn gangue dump. However, limited is known that how these processes influence the environmental behaviors of Hg in waterbody. Therefore, the seasonal distribution and existing form of Hg in water and sediment in one Mn ore area in Xiushan County, Chongqing were investigated. Our results showed that the mean Hg and methylmercury(Me Hg) concentrations in water( n = 35) were 5.8 ± 4.6 ng/L and 0.22 ± 0.14 ng/L, respectively. The mean Hg concentrations in retained riverbed and fluvial bank sediment( n = 35) were 0.74 ± 0.26 mg/kg and 0.63 ± 0.27 mg/kg, respectively(the mean Me Hg concentrations were 0.64 ± 0.40 μg/kg and 0.51 ± 0.30 μg/kg, respectively). It indicated that the mining and smelting of Mn ores were the main sources of anthropogenic Hg, and Mn may inhibit Hg methylation in rivers in Mn ore areas. Mercury in the bound to iron/Mn(Fe/Mn) oxides of low crystallinity fraction(Hg-OX) accounted for 4.01% and 5.25% of the total Hg concentrations in the retained riverbed and fluvial bank sediment, respectively. The amount of Hg bound to Fe/Mn oxides in sediment increased significantly due to the manganese mining activities in the investigated area. Therefore, it could be hypothesized that high Hg concentrations in river sediment in Mn mining areas are closely related to high Mn concentration in sediment.

关 键 词：Mn mining area HG MeHg Distribution characteristics Fractionation of Hg 

分 类 号：X52[环境科学与工程—环境工程]