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51.
酸沉降物对土壤化学性质的影响 总被引:1,自引:0,他引:1
本文综述了酸沉降物对土壤酸化、营养物质的淋溶、重金属的活化、矿物分解等化学性质的影响,以及阻止酸雨危害土壤的化学方法。 相似文献
52.
The Clean Air Act Amendments of 1977 designated national parks and wilderness areas larger than 1894 ha to be class I areas
for air quality management, setting more restrictive criteria than the National Ambient Air Quality Standards. Class I areas
are afforded the greatest degree of air quality protection under the Clear Air Act of 1970. In recent years, several studies
have documented air pollution effects in the Great Smoky Mountains National Park (GSMNP), the second-largest class I area
in the eastern United States. Air pollution problems of greatest concern in the GSMNP are effects of acid deposition, visibility
impairment, and tropospheric ozone. Several recent events have increased concerns about air quality management in the class
I area of the GSMNP. A forum, sponsored by the Southern Appalachian Man and the Biosphere Cooperative (SAMAB), was held in
March 1992, which involved representative. parties-at-interest and began to address strategies for better management of air
resources in the Southern Appalachians. This paper summarizes those discussions and recommendations and reports actions occurring
as a result of the forum. Another objective of this paper is to present a conceptual framework for more effective management
of the class I area of the GSMNP. 相似文献
53.
Acid rain in Asia 总被引:3,自引:0,他引:3
Acid rain has been an issue of great concern in North America and Europe during the past several decades. However, due to the passage of a number of recent regulations, most notably the Clean Air Act in the United States in 1990, there is an emerging perception that the problem in these Western nations is nearing solution. The situation in the developing world, particularly in Asia, is much bleaker. Given the policies of many Asian nations to achieve levels of development comparable with the industrialized world—which necessitate a significant expansion of energy consumption (most derived from indigenous coal reserves)—the potential for the formation of, and damage from, acid deposition in these developing countries is very high. This article delineates and assesses the emissions patterns, meteorology, physical geology, and biological and cultural resources present in various Asian nations. Based on this analysis and the risk factors to acidification, it is concluded that a number of areas in Asia are currently vulnerable to acid rain. These regions include Japan, North and South Korea, southern China, and the mountainous portions of Southeast Asia and southwestern India. Furthermore, with accelerated development (and its attendant increase in energy use and production of emissions of acid deposition precursors) in many nations of Asia, it is likely that other regions will also be affected by acidification in the near future. Based on the results of this overview, it is clear that acid deposition has significant potential to impact the Asian region. However, empirical evidence is urgently needed to confirm this and to provide early warning of increases in the magnitude and spread of acid deposition and its effects throughout this part of the world. 相似文献
54.
The objective of this research was to analyze the retention of acid precipitation as a viable policy issue on the Congressional
agenda during the 1980s. Issue maintenance (a term borrowed from Barbara Nelson's discussion of the four stages associated
with agenda decision making) was examined in relation to a set of issue characteristics originally developed by Roger Cobb
and Charles Elder, i.e., concreteness, social significance, temporal relevance, complexity, and categorical precedence. Each
issue attribute was found to be somewhat useful in explaining the longevity of acid rain as an agenda item although the direction
of influence for two factors, complexity and temporal relevance, was contrary to expectations. It was suggested that a conceptual
merger of this sort could contribute to the comparative analysis of agenda policy decisions by providing a clearer and more
restricted set of decision points to be explained. 相似文献
55.
大气中SO2的液相氧化研究 总被引:2,自引:0,他引:2
大气中SO2液相氧化是形成酸雨的重要途径,降雨中含有各种无机离子和有机物质,它们可能催化或抑制液相氧化反应的进行。本文根据四川酸雨样品组成,进行了SO2在模拟雨水及实际雨水中的氧化实验,考查了V,Fe,Mn等离子对SO2氧化的催化作用,H2O2对SO2的氧化以及降水中有机物质甲醛对各反应的影响。实验结果为了解酸雨的成固,研究酸雨控制对策提供了科学依据。 相似文献
56.
Mineralogical compositions and their spatial distributions are important initial conditions for reactive transport modeling. However, popular Kd-based "reactive" transport models only require contaminant concentrations in the pore fluids as initial conditions, and minerals implicitly represent infinite sources and sinks in these models. That situation results in a general neglect of mineralogical characterization in site investigations. This study uses a coupled multi-component reactive mass transport model to predict the natural attenuation of a ground water plume at a uranium mill tailings site in western USA. Numerous ground water geochemistry data are available at this site, but mineralogical data are sketchy. Even given the well-defined pore fluid chemistry, variations of secondary mineral species and mineral abundances in the aquifer resulted in significantly different modeling outcomes. Results show that the amount of calcite in the aquifer determines the distances of plume migration. The possible presence of jurbanite, an aluminum sulfate phase, can store acidity temporarily but cause more severe contamination on a later date. The surfaces of iron oxyhydroxides can store significant amounts of sulfate and protons and serve as a second source for prolonged contamination. These simulations under field conditions illustrate that mineralogical compositions are an essential requirement for accurate prediction of contaminant fate and transport. 相似文献
57.
B. Bharathiraja J. Jayamuthunagai R. Praveenkumar M. Jayakumar S. Palani 《International Journal of Green Energy》2015,12(10):1012-1017
Recent research and technology have provided promising outcomes to rely on biodiesel as the alternative and conventional source of fuel. The use of renewable sources constitutes the main stream of research. Waste Cooking Oil (WCO) was used for biodiesel production in this study. Lipase enzyme producing fungi Rhizopus oryzae 262 and commercially available pure lipase enzyme were used for comparative study in the production of FAAE. The whole cell biocatalyst and pure enzyme were immobilized using calcium alginate beads. It was prepared by optimizing with different molar ratios of calcium chloride and different percent sodium alginate. Entrapment immobilization was done for whole cell biocatalyst. PE was also immobilized by entrapment for the transesterification reaction. Four different solvents methanol, ethanol, n-propanol, n-butanol were used as the acyl acceptors. The reaction parameters like temperature, molar ratio, reaction time, and amount of enzyme to be used were also optimized for methanol alone. The same parameters were adopted for the other acyl acceptors too. Among the different acyl acceptors, methanol whose reaction parameters were optimized showed maximum conversion of triglycerides to FAAE - 94% with PE and 84% with WCB. On the whole, PE showed better catalytic converting ability with all the acyl acceptor compared to WCB, further study, it was observed that three consecutive and reversible reactions occurred in the interesterification of triglycerides. So, a kinetic model based on Michaelis-Menten equation with competitive substrate inhibition was used to find the maximum reaction rate Vi for the four solvents using pure enzyme and WCB. 相似文献
58.
优化沉积物中酸挥发性硫化物(Acid Volatile Sulfide,AVS)的提取方法并采用连续流动分析法检测提取液中的硫化物.研究了吸收液的种类、氮气流量与吹气的时间和反应温度对AVS提取效果的影响以优化提取方法.结果表明,与传统的氢氧化钠或硫酸镉-氢氧化钠吸收液相比,以氯化锌-羧甲基纤维素钠溶液为吸收液吸附效率好,稳定性高且无毒.用连续流动分析法检测提取液中的AVS快速、准确、稳定性好. 相似文献
59.
Response of Fish and Macroinvertebrate Bioassessment Indices to Water Chemistry in a Mined Appalachian Watershed 总被引:1,自引:0,他引:1
Multimetric indices based on fish and benthic macroinvertebrate assemblages are commonly used to assess the biological integrity
of aquatic ecosystems. However, their response to specific stressors is rarely known. We quantified the response of a fish-based
index (Mid-Atlantic Highlands Index of Biotic Integrity, MAH-IBI) and a benthic invertebrate-based index (West Virginia Stream
Condition Index, WV-SCI) to acid mine drainage (AMD)-related stressors in 46 stream sites within the Cheat River watershed,
West Virginia. We also identified specific stressor concentrations at which biological impairment was always or never observed.
Water chemistry was extremely variable among tributaries of the Cheat River, and the WV-SCI was highly responsive across a
range of AMD stressor levels. Furthermore, impairment to macroinvertebrate communities was observed at relatively low stressor
concentrations, especially when compared to state water quality standards. In contrast to the WV-SCI, we found that the MAH-IBI
was significantly less responsive to local water quality conditions. Low fish diversity was observed in several streams that
possessed relatively good water quality. This pattern was especially pronounced in highly degraded subwatersheds, suggesting
that regional conditions may have a strong influence on fish assemblages in this system. Our results indicate that biomonitoring
programs in mined watersheds should include both benthic invertebrates, which are consistent indicators of local conditions,
and fishes, which may be indicators of regional conditions. In addition, remediation programs must address the full suite
of chemical constituents in AMD and focus on improving linkages among streams within drainage networks to ensure recovery
of invertebrate and fish assemblages. Future research should identify the precise chemical conditions necessary to maintain
biological integrity in mined Appalachian watersheds. 相似文献
60.
Acid mine drainage (AMD), resulting from open-cast coal mining, is currently one of the largest environmental challenges facing the mining industry. In this study, a life cycle assessment (LCA) was conducted to evaluate the environmental impacts associated with the construction, operation and maintenance of different AMD treatment options typically employed. LCA is a well-reported tool but is not documented for AMD treatment systems despite their ubiquitous implementation worldwide. This study conducted detailed LCA analysis for various passive and active AMD treatment approaches implemented or considered at a major coal mine in New Zealand using a comparative functional unit of kg acidity removed per day for each treatment option. Eight treatment scenarios were assessed including active limestone and hydrated lime treatments, and compared to passive treatments using limestone and waste materials such as mussel shells. Both midpoint and endpoint LCA impact categories were assessed. Generally, the active treatment scenarios demonstrated greater LCA impacts compared to an equivalent level of treatment for the passive treatment approaches. Lime slaking had the greatest LCA impacts, while passive treatment approaches incurred consistently less impacts except for one passive treatment with a purchased energy scenario. A 50% reduction in transportation distances resulted in the lowest LCA impacts for all scenarios. This study highlights the importance of evaluating the environmental and social impacts of AMD treatment for the mining industry. 相似文献