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In this study, the content and speciation of arsenic in coal waste and gas condensates from coal waste fires were investigated,
respectively, using the digestion and sequential extraction methods. The fresh and fired-coal waste samples were collected
from Yangquan, which is one of the major coal production regions in northern China. High-performance liquid chromatography-inductively
coupled plasma-mass spectrometry (HPLC-ICP-MS) was used to determine the concentrations of four major arsenic species [As(III),
As(V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA)] in the extracts, while ICP-MS was used to measure total
As content. Arsenic content in the investigated coal wastes and the condensate ranges between 23.3 and 69.3 mg/kg, which are
higher than its reported average content in soils. Arsenic in coal waste exists primarily in the residual fraction; this is
followed in decreasing order by the organic matter-bound, Fe–Mn oxides-bound, exchangeable, carbonates-bound, and water-soluble
fractions. The high content of arsenic in the condensates indicates that combustion or spontaneous combustion is one of the
major ways for arsenic release into the environment from coal waste. About 15% of the arsenic in the condensate sample is
labile and can release into the environment under leaching processes. The water extractable arsenic (WEA) in the fresh coal
waste, fired coal wastes, and the condensate varied between 14.6 and 341 μg/kg, with As(V) as the major species. Furthermore,
both MMA and DMA were found in fresh coal wastes, fired coal wastes, and the condensate. 相似文献
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Cai Kui Du Juan Dai Cong Hu Huabin . Center for Rural Development Studies Yunnan University Kunming Yunnan China . Institute of Ethnology Yunnan Academy of Social Science Kunming Yunnan China . Institute of Economics Yunnan Academy of Social Science Kunming Yunnan China . Xishuangbanna Tropical Botany Garden Chinese Academy of Sciences Kunming Yunan China 《中国人口.资源与环境(英文版)》2007,5(2):78-83
A three-year study over the Bai, Jingpo and Huayaodai communities in Yunnan Province reveals that the community development is significantly influenced in various ways by such cultural factors as the concepts of development; concepts and traditions of inter-community relationships, consumption, mar- riage and gender; patterns of decision-making and production, resource and income allocation; as well as the role of information dissemination systems, religion and ritual. Based on the analysis over the interactive relevance between each factor and community development, some strategies and methods for dealing with such a cultural relevance in development projects are recommended. 相似文献
366.
针对武钢7~#焦炉存在的污染问题,进行了治理改造,采用热浮力罩除尘车,使集尘、除尘、生产于一体,运行后使除尘系统烟气净化效率得到提高,各种污染物都得到了降低。 相似文献
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Wuyang Hu Jerrod Penn Marie Pelton Angelos Pagoulatos 《Journal of Environmental Planning and Management》2015,58(7):1154-1172
Recreational horseback riding is an important, but less studied, component of human interaction with the natural environment and often occurs alongside other outdoor recreational activities. Using choice experiment data collected from a survey conducted in Kentucky, this study assesses rider preferences and economic values associated with various equestrian trail attributes for daylong horseback riding trips in rural trail systems. Results indicate that while individuals have different opinions, trail attributes such as length of trail, scenic views, and travel distance from home all have significant economic implications. In addition, riders prefer trails that are restricted for horse riding only. Willingness to pay estimates of all attributes increase substantially when the travel cost to reach the trail is also considered. Policy implications on maintaining current and creating new trails in a multi-user setting are given, such as the opportunities for separating horseback riders from other users while still providing other beneficial attributes like options for longer trails and scenic views to all groups. 相似文献
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生活垃圾循环流化床焚烧锅炉飞灰中二噁英热解析特性研究 总被引:1,自引:0,他引:1
实际垃圾焚烧系统中飞灰会在尾部烟道堆积并在受热后发生二噁英的再生成、热降解及向烟气解析等协同作用.本文研究了半干法脱硫塔前生活垃圾焚烧飞灰在受热过程中二噁英的质量变化及其气固相分布情况,重点研究了反应温度、含氧量及硫胺基复合阻滞剂的添加等对飞灰中二噁英热解析特性的影响.试验结果表明,250℃时飞灰析出的气相二噁英很少,而450℃时气相二噁英的比例高达99.7%;氧含量对飞灰中二噁英的热解析特性影响较大,当氧含量为6%时,气相二噁英的析出量最大,达到2.87 ng·g-1;350℃时添加硫胺基复合阻滞剂后二噁英总量明显下降,表明阻滞剂能够抑制二噁英再合成,但气相中二噁英的比例从47.69%上升到87.50%. 相似文献