摘要
为弄清陡河燃煤电厂大气汞沉降对毗邻的陡河水库沉积物中总汞、甲基汞的贡献及其污染程度,于2013年8月对陡河水库沉积物进行了采样,测定了沉积物中总汞、甲基汞、有机质以及孔隙水中溶解态汞含量等参数,运用地累积指数法评价了陡河水库沉积物的汞污染现状和污染程度.结果表明,陡河水库沉积物中总汞含量(dw)范围为19~97 ng·g^(-1),甲基汞含量(dw)范围为0.02~1.27 ng·g^(-1),均表现为表层高于底层,说明陡河水库沉积物的汞含量正逐年升高,外源汞输入对陡河沉积物负荷产生了一定的影响.受电厂大气汞干湿沉降影响,陡河水库周边土壤汞含量(dw)平均值为22 ng·g^(-1),而陡河水库3个沉积物柱库心总汞含量最高,其次为西支,东支最低.结合上游大黑汀水库较高的沉积物汞含量(总汞平均值为176 ng·g^(-1)),以及陡河水库附近较低的土壤汞含量,初步判断陡河水库沉积物中汞的主要来源为大黑汀水库的高汞水源输入,电厂汞沉积输入贡献相对较小.陡河沉积物总汞、甲基汞与有机质之间均呈显著的正相关关系,表明沉积物中有机质具有较好的吸附总汞和甲基汞的能力,并对甲基汞产生具有重要作用.地累积指数Igeo的评价结果表明,陡河水库各点位沉积物的汞污染程度依次为库心>西支>东支,库心和西支属于中度污染,东支属于轻微污染.大黑汀水库受周边采矿企业影响,两个采样点沉积物的地累积指数污染评价属于中强污染和强污染.
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（ Me Hg）,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-1. dw,Me Hg（ dw） from0. 02 to 1. 27 ng·g-1,and the contents of both THg and Me Hg 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-1. 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-1. 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 Me Hg in the sediments of Douhe reservoir were positively correlated with OM,indicating that OM in sediments had good ability of adsorbing THg and Me Hg,and also played an important role in Hg methylation.The geoaccumulation index（ Igeo） 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
作者
吴婷婷
王明猛
陈旭锋
刘文利
李太山
闫海鱼
何天容
李仲根
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 Tangshan Municipal Environmental Monitoring Center, Tangshan 063000, China State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2017年第3期979-986,共8页
Environmental Science
基金
唐山市科学技术研究与发展计划项目(12130215A)
国家重点基础研究发展规划(973)项目(2013CB43001)
国家自然科学基金项目(41373056
41273099)
关键词
陡河水库
沉积物
总汞
甲基汞
污染评价
Douhe reservoir
sediment
total mercury
methyl mercury
pollution assessment
