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Transport and fate of mercury under different hydrologic regimes in polluted stream in mining area

Journal of Environmental sciences 2011年第5期23卷 757-764页

作者： Yan Lin Thorjorn Larssen Rolf D. Vogt Xinbin Feng Hua Zhang Department of Chemistry University of Oslo POB 1033 0315 Oslo Norway. E-mail:yan.lin@kjemi.uio.no Norwegian Institute for Water Research Gaustadalleen 21 0349 Oslo Norway State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

Seepage from Hg mine wastes and calcines contains high concentrations of mercury （Hg）. Hg pollution is a major environmental problem in areas with abandoned mercury mines and retorting units. This study evaluates factors, especially the hydrological and sedimentary variables, governing temporal and spatial variation in levels and state of mercury in streams impacted by Hg contaminated runoff. Samples were taken during different flow regimes in the wanshan Hg mining area in Guizhou Province, China. In its headwaters the sampled streams/rivers pass by several mine wastes and calcines with high concentration of Hg. Seepage causes serious Hg contamination to the downstream area. Concentrations of Hg in water samples showed significant seasonal variations. Periods of higher flow showed high concentrations of total Hg （THg） in water due to more particles being re-suspended and transported. The concentrations of major anions （e.g., Cl-, F-, NO3- and SO4^2-） were lower during higher flow due to dilution. Due to both sedimentation of particles and dilution from tributaries the concentration of THg decreased from 2100 ng/L to background levels （〈 50 ng/L） within 10 km distance downstream. Sedimentation is the main reason for the fast decrease of the concentration, it accounts for 69% and 60% for higher flow and lower flow regimes respectively in the upper part of the stream. Speciation calculation of the dissolved Hg fraction （DHg）（using Visual MINTEQ） showed that Hg（OH）2 associated with dissolved organic matter is the main form of Hg in dissolved phase in surface waters in wanshan （over 95%）.

关键词： mercury hydrology temporal variation fractionation and speciation

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Mineralogical characteristics of soil dust from source regions in northern China

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Particuology 2009年第6期7卷 507-512页

作者： Zhenxing Shen Sandrine Caquineau Junji Cao Xiaoye Zhang Yuemei Han Annie Gaudichet Laurent Gomes Department of Environmental Science and Engineering Xi'an Jiaotong University Xi'an China SKLLQG Institute of Earth Environment Chinese Academy of Sciences Xi'an China Institut de Recherche pour le Developpement 32 av. H. Varagnat 93143 Bondy cedex France LISA UMR-CNRS-7583 61 av. de Gal de Gaulle. 94010 Creteil France Meteo-France/CNRM URA I357 42 av. G. Coriolis 31057 Toulouse cedex France

Mineral compositions of aerosol particles were investigated at four sites （Aksu, Dunhuang, Zhenbeitai, and Tongliao） in desert regions of northern China from March to May in 2001 and 2002 during the intensive field campaign period of ACE-Asia （Aerosol Characterization Experiments-Asia）. The X-ray diffraction （XRD） results show the main minerals for Asian dust are illite, chlorite, kaolinite, quartz, feldspar, calcite, and dolomite. Gypsum, hornblende, and halite are also detected in several samples. Semi-quantitative mineralogical data of aerosol samples show that carbonate content decreases from western to eastern source areas; that is, soil dust collected at western source area sites of Dunhuang and Aksu are enriched with carbonate, while northeastern source area site of Tongliao is associated with low carbonate content. But the spatial distribution of feldspar exhibits a different pattern as compared to carbonate, increasing from the western to the eastern sources. The total clay content is significantly higher （73% in average） at the deposition site of Changwu than those at source areas. Air-mass back trajectory studies for the three dust storm events observed at Changwu, showed that soil dust transport pathways were as expected from carbonate content for the source identification, further demonstrating that carbonate was a useful tracer for eolian dust on regional scale in northern China.

关键词： Soil dust Mineralogical composition Carbonate Tracer

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Genetic relationships of introduced Colorado potato beetle Leptinotarsa decemlineata populations in Xinjiang, China

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Insect Science 2013年第5期20卷 643-654页

作者： Jing-Jie Zhang Juan Yang Ying-Chao Li Ning Liu Run-Zhi Zhang Key Laboratory of Zoological Systematics and Evolution Institute of Zoology Chinese Academy of Sciences Graduate University of chinese academy of sciences Beijing College of Agriculture Guangxi University Nanning Beijing Forestry University State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China

The Colorado potato beetle （CPB）, Leptinotarsa decemlineata （Say）, is an infamous invasive species worldwide that aggressively attacks potato and other Solanaceae crops. CPB was first found in China in 1993 and has since spread across 2.77 × 105 km2 in Xinjiang Uygur Autonomous Region. To better understand genetic variation and migration patterns, we used seven polymorphic microsatellite loci to elucidate the genetic relationships and gene flow among 10 CPB populations across Xinjiang. （i） Overall low levels of genetic diversity were detected on the entire population in Xinjiang but most of the diversity was retained among populations during invasion. （ii） The mean pairwise FST was low （0.071 ± 0.043） among populations. The genetic differentiation was little （pairwise FST 0.038 ± 0.016） between the five interior populations （Wusu, Urumqi, Jimsar, Qitai and Mulei） and Tacheng population. The six populations might come from the same genetic group via Bayesian clustering and were closely related on a neighbor-joining tree. Combining the history data, the five interior populations may have originated from Tacheng. （iii） Gene flow was frequent, especially among the five interior populations. Individuals from the interior populations could be assigned to Tacheng at higher probabilities （means 0.518 ± 0.127） than vice versa （means 0.328 ± 0.074）, suggesting that the beetle population has spread from the border to the interior in Xinjiang.

关键词： China Colorado potato beetle genetic variation invasive pest Leptinotarsa decemlineata Xinjiang

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