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11.
Xinbin FENG Shaofeng WANG Guangle QIU Yamin HOU Shunlin TANG 《中国地球化学学报》2006,25(B08):243-244
Guizhou is located in the Circum-Pacific Global Mercuriferous Belt, and mercury concentrations in soil in this area are enriched. In-situ total gaseous mercury (TGM) exchange fluxes between air and soil surface were intensively measured at four sampling sites in Guiyang from 21 May to 16 June, 2003, and five sites in the Lanmuchang mercury mining area in December 2002 and May 2003, respectively. The in-situ Hg flux measurement was conducted with a dynamic flux chamber (DFC) of quartz. Overall, net emissions were obtained from all sampling sites. Soil mercury concentration and solar radiation have been proved to be the two most important parameters to control mercury emissions from soil. Meanwhile, rain events can enhance mercury emission rate significantly. 相似文献
12.
环境样品中痕量元素的化学形态分析Ⅱ.砷汞镉锡铅硒铬的形态分析 总被引:2,自引:6,他引:2
环境中元素的生物有效性和毒性依赖于其存在的化学形态。文章依据文献的有关报道介绍砷、汞、镉、锡、铅、硒和铬在环境中的分布、毒性及它们在环境样品如水、土壤、沉积物和生物体中的形态分析方法,包括分析物的保存、提取、分离和检测。引用文献120篇。 相似文献
13.
The environmental impact of small-scale gold mining in Ghana: identifying problems and possible solutions 总被引:2,自引:0,他引:2
Gavin Hilson 《The Geographical journal》2002,168(1):57-72
This paper examines the environmental impacts of small-scale gold mining in Ghana, and prescribes a series of recommendations for improving environmental performance in the industry. Since the enactment of the Small Scale Gold Mining Law in 1989, which effectively legalized small-scale gold mining in the country, industrial operations, collectively, have made important contributions to national gold output, foreign exchange earnings and employment. Accompanying this pattern of socio-economic growth, however, have been increased environmental complications – namely, mercury pollution and land degradation. The Ghanaian Minerals Commission has been burdened with most of the jurisdictional responsibilities related to small-scale mining, but with a staff of only 35–40 people working with a pool of highly obsolete research resources, it is clearly incapable of facilitating sufficient environmental improvement on its own. It is concluded that marked environmental improvements can only be achieved if: (1) assistance is provided to the Minerals Commission from local governmental bodies and academic units; (2) industry-specific environmental management tools and strategies are designed and implemented; (3) concerted effort is made to prospect for deposits suitable for small-scale gold mining, a key to preventing unnecessary exploration; and (4) a nation-wide industrial mercury study is commissioned, and a mercury retorting programme is implemented. 相似文献
14.
15.
Paul J. Lechler Jerry R. Miller Liang-Chi Hsu Mario O. Desilets 《Journal of Geochemical Exploration》1997,58(2-3)
The Carson River Superfund Site in west-central Nevada is an area of Hg-contaminated soil, sediment, water, air, and biola resulting from the amalgamation milling of Ag-Au ores of the Comstock lode worked approximately a century ago. In order to develop an understanding of the behavior, transport, and fate of Hg at this site, a technique was developed to estimate the proportions of total, elemental, exchangeable, organic, and sulfide Hg in soils, sediments, and tailings.Results of this analysis performed on active Carson River sediments indicate that Hg is selectively dissolved out of Hg-Au amalgam particles and subsequently adsorbed to fine-grained sediments which are then deposited in downstream, low-energy reaches of the Carson River and Labontan Reservoir. In the relatively more-reducing environment of the reservoir Hg appears to be converted, in large part, to relatively-insoluble HgS.The original elemental form of Hg released to the environment is the chemical form which is still dominant in most highly-contaminated soils, sediments, and tailings. Deeper, more-reducing soil horizons, however, appear to fix a significant portion of the Hg as HgS, analogous to the Lahontan Reservoir example described above. This fixation as HgS is documented to be largely limited to higher-sulfur areas where sulfide minerals from the Comstock ores increase the total sulfur concentrations of contaminated soils, sediments, and tailings. 相似文献
16.
正态化克立格法是对传统储量计算方法的改革和创新。其计算过程的科学性和计算结果的正确性在路腊汞矿作了探采对比试算,取得了良好的结果。 相似文献
17.
夏季红枫湖地区农田土壤-大气界面汞交换通量的初步研究 总被引:11,自引:2,他引:11
采用动力学通量箱法(Dynamic Flux Chamber)与高时间分辨率大气测汞仪联用技术对贵州红枫湖地区土壤-大气界面间汞交换通量进行了初步研究.结果显示,红枫湖地区土壤-大气界面间汞交换通量变化范围为-8.6 ng~215.3 ng@m-2@h-1,平均27.4士40.1 ng/m2@h(n=255);且土壤与大气界面间的汞交换是双向的既有土壤汞的释放,又有大气汞的沉降,主要以土壤汞的释放为主(n释放=253,n沉降=2n).土壤汞的释放通量与土壤温度、气温、光照强度有强相关关系,相关系数分别为0.80、0.83、0.74. 相似文献
18.
松花江上游地区汞污染的化学生态效应 总被引:5,自引:0,他引:5
采样分析了吉林省东部松花江上游金矿开采区及其附近水、土壤、动植物及河流沉积物样品中汞的含量,发现河流沉积物中汞的污染相当严重;受其影响当地的植物和两栖类动物——中国林蛙体内总汞和甲基汞含量也明显高于对照组。实验表明,林蛙内脏对汞的富集能力大于肌肉;秋季对汞的富集大于春季;河流沉积物中甲基汞的含量与林蛙体内甲基汞的含量有较好的正相关。汞污染的来源与区域内个体金矿的滥采滥排有直接关系,表明人类活动所产生的有毒重金属在地表过程中出现了化学生态效应。 相似文献
19.
Mercury and methylmercury biogeochemistry in a thawing permafrost wetland complex,Northwest Territories,Canada 下载免费PDF全文
In arctic and sub‐arctic environments, mercury (Hg), more specifically toxic methylmercury (MeHg), is of growing concern to local communities because of its accumulation in fish. In these regions, there is particular interest in the potential mobilization of atmospherically deposited Hg sequestered in permafrost that is thawing at unprecedented rates. Permafrost thaw and the resulting ground surface subsidence transforms forested peat plateaus into treeless and permafrost‐free thermokarst wetlands where inorganic Hg released from the thawed permafrost and draining from the surrounding peat plateaus may be transformed to MeHg. This study begins to characterize the spatial distribution of MeHg in a peat plateau–thermokarst wetland complex, a feature that prevails throughout the wetland‐dominated southern margin of thawing discontinuous permafrost in Canada's Northwest Territories. We measured pore water total Hg, MeHg, dissolved organic matter characteristics and general water chemistry parameters to evaluate the role of permafrost thaw on the pattern of water chemistry. A gradient in vegetation composition, water chemistry and dissolved organic matter characteristics followed a toposequence from the ombrotrophic bogs near the crest of the complex to poor fens at its downslope margins. We found that pore waters in poor fens contained elevated levels of MeHg, and the water draining from these features had dissolved MeHg concentrations 4.5 to 14.5 times higher than the water draining from the bogs. It was determined through analysis of historical aerial images that the poor fens in the toposequence had formed relatively recently (early 1970s) as a result of permafrost thaw. Differences between the fens and bogs are likely to be a result of their differences in groundwater function, and this suggests that permafrost thaw in this landscape can result in hotspots for Hg methylation that are hydrologically connected to downstream ecosystems. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
20.
Long‐term monitoring of a mercury contaminated estuary (Ria de Aveiro,Portugal): the effect of weather events and management in mercury transport 下载免费PDF全文
J. P. Coelho P. Pato B. Henriques A. Picado A. I. Lillebø J. M. Dias A. C. Duarte M. E. Pereira M. A. Pardal 《水文研究》2014,28(2):352-360
The main aim of this research was to assess the mercury transport from an estuarine basin with a background of anthropogenic contamination during a spring tidal cycle (year 2009) and compare it with two previous tidal cycles (years 1994 and 1999), as part of a long‐term monitoring program. Results showed that effective mercury transport occurs both in the dissolved and particulate fractions (0.18 and 0.20 kg per tidal cycle, respectively), and despite an overall decrease in environmental contamination, results more than double previous findings on particulate transport in the system. These findings result essentially from changes in the tidal prism (net export of 2 million m3 of water), given that both dissolved and particulate concentrations did not increase over time. Hydrodynamic simulations were performed to evaluate the effect of physical disturbance (dredging) and weather events (increased freshwater flow) in these processes, and results suggest the increased freshwater flow into the system as the main forcing function for the mercury transport increment. These results highlight the importance of long‐term monitoring programs, since despite an overall improvement in local contamination levels, the enhancement of transport processes through hydrological changes increases environmental pressure away from the contamination source. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献