Wu Ting-Ting, Wang Ming-Meng, Chen Xu-Feng, Liu Wen-Li, Li Tai-Shan, Yan Hai-Yu, He Tian-Rong, Li Zhong-Gen
Key Laboratory of Karst Environment and Geohazard Prevention, Guizhou University, Guiyang 550003, China.
College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
Huan Jing Ke Xue. 2017 Mar 8;38(3):979-986. doi: 10.13227/j.hjkx.201609088.
Sediment cores from Douhe reservoir in Tangshan City were sampled in August 2013, in order to evaluate the mercury (Hg) pollution degree and its possible sources. Agriculture soils surrounding the Douhe reservoir and sediments from an upstream reservoir (Daheiting) were also collected. Total mercury (THg), methylmercury (MeHg), dissolved mercury in pore water (DHg) and organic matter (OM) in sediment of Douhe reservoir were analyzed, while, only THg in the agriculture soils and upstream reservoir sediments was determined. Finally, the geoaccumulation index method was applied to evaluate the Hg pollution status in soils and reservoir sediments. The results showed that THg content in sediment of Douhe reservoir ranged from 19 to 97 ng·g. dw, MeHg (dw) from 0.02 to 1.27 ng·g, and the contents of both THg and MeHg were higher in the upper layers than the deeper layers, indicating that Hg in sediments was increasing in recent years by the exogenetic loadings. THg (dw) in soils offshore the Douhe reservoir, which is close to a large coal-fired power plant, averaged at 22 ng·g. Among the three sediment cores of Douhe reservoir, the central point had the highest THg, followed by the western site, and the eastern site had the lowest THg. While, THg content (dw) in sediments of Daheiting reservoir was much higher, with a mean of 176 ng·g. Combining all the above information, we concluded that Hg in Douhe reservoir was mainly derived from the Daheiting reservoir and the mercury atmospheric deposition from the nearby coal-fired power plant contributed a less content. THg and MeHg in the sediments of Douhe reservoir were positively correlated with OM, indicating that OM in sediments had good ability of adsorbing THg and MeHg, and also played an important role in Hg methylation. The geoaccumulation index (I) showed that the Hg pollution status deceased in this order:central of Daheting, Daba of Daheting, central of Douhe, western of Douhe, eastern of Douhe, soils surrounding Douhe. Central and western sites in Douhe belonged to moderate pollution and the eastern site belonged to slight pollution. While, sediments of Daheiting reservoir, affected by the iron ore mining activities, were in the moderate and strong pollution status.
2013年8月采集了唐山市陡河水库的沉积物岩芯，以评估汞（Hg）污染程度及其可能来源。还采集了陡河水库周边的农业土壤和上游水库（大黑汀）的沉积物。分析了陡河水库沉积物中的总汞（THg）、甲基汞（MeHg）、孔隙水中的溶解汞（DHg）和有机质（OM），而仅测定了农业土壤和上游水库沉积物中的总汞。最后，应用地累积指数法评估土壤和水库沉积物中的汞污染状况。结果表明，陡河水库沉积物中的总汞含量范围为19至97 ng·g（干重），甲基汞（干重）为0.02至1.27 ng·g，总汞和甲基汞的含量在上层均高于深层，表明近年来沉积物中的汞因外源性负荷而增加。靠近大型燃煤电厂的陡河水库近海土壤中的总汞（干重）平均为22 ng·g。在陡河水库的三个沉积物岩芯中，中心点的总汞含量最高，其次是西部站点，东部站点的总汞含量最低。而大黑汀水库沉积物中的总汞含量（干重）要高得多，平均为176 ng·g。综合上述所有信息，我们得出结论，陡河水库中的汞主要来自大黑汀水库，附近燃煤电厂的汞大气沉降贡献的含量较少。陡河水库沉积物中的总汞和甲基汞与有机质呈正相关，表明沉积物中的有机质具有良好的吸附总汞和甲基汞的能力，并且在汞甲基化中也起着重要作用。地累积指数（I）表明汞污染状况按以下顺序递减：大黑汀中部、大黑汀大坝、陡河中部、陡河西部、陡河东部、陡河周边土壤。陡河的中部和西部站点属于中度污染，东部站点属于轻度污染。而受铁矿石开采活动影响的大黑汀水库沉积物处于中度和重度污染状态。
