共查询到20条相似文献,搜索用时 93 毫秒
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为了探究土壤中二噁英类测定的关键前处理技术,确保土壤测定结果能真实反映二噁英类污染水平,选取一批次土壤样品,通过对样品前处理过程是否进行盐酸发泡处理、索氏提取和ASE提取两种不同的样品提取方式、不同的多层复合硅胶柱净化次数、不同的活性碳柱净化次数等进行比较。研究结果表明盐酸发泡处理后的结果更接近土壤实际值。第一步净化操作中C1、C2、C3、C4样品的毒性当量浓度分别是8.4、1.8、2.1、1.6 ngTEQ/kg,说明在遇到复杂基体样品时,需要进行两次硅胶柱净化处理,才能达到更好的去除干扰物的目的。第二步活性碳柱净化步骤中,使用一次净化即可达到较为满意的结果。研究结果为土壤中二噁英类测定的关键前处理过程提供了数据支持,为深入打好土壤中持久性有机污染防治攻坚提供了技术支撑。 相似文献
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沉淀浮选法处理矿山含重金属废水技术初探 总被引:6,自引:1,他引:6
本文介绍了一种新的废水处理技术-沉淀浮选法处理矿山含重金属废水的性能,并对其净化机理作了探讨,还将其与传统的化学沉淀净化法作了比较,为矿山废水的治理及综合利用指出了一条切实可行的新途径。 相似文献
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对800m^3/d的牛仔漂洗废水采用絮凝沉淀+水解酸化与接触氧化工艺进行处理,通过6个月的调试与运行,挂膜好,处理效果稳定,CODCr去除率在89%以上。色度和CODCr有大幅度降低,一般情况下能保证出水水质达标。 相似文献
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水泥工业清洁生产与环境保护初探 总被引:2,自引:0,他引:2
水泥工业是个能耗高、污染物排放量大的重污染行业,其对环境的污染主要是粉尘污染。在水泥厂实施清洁生产的潜力很大,不仅可以降低能耗、物耗,减少污染物的排放,同时,由于加强了管理,有助于提高生产效率,提高产品质量,降低生产成本,增强市场竞争力,可产生明显的经济、环境和社会效益 相似文献
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Robert Garner 《Journal of Agricultural and Environmental Ethics》2017,30(4):579-584
Applying competing ethical theories to the issue of bovine TB and badger culling can throw light on the validity of the policy options. Utilitarianism is, superficially at least, an attractive option. However, the aggregative principle is problematic and this is well illustrated in the case of bovine TB and badger culling. Such is the variety and strength of interests to be considered that it is not at all clear which course of action will maximise utility. In addition, it may be that the full range of consequences can never be known with any degree of accuracy. An alternative option is to revert to an animal welfare ethic. This has the effect of cutting down the moral complexities involved in a discussion of bovine TB and badger culling, since, providing it is done humanely, killing badgers is not an ethical issue, and even the infliction of suffering on them is permissible providing it serves a significant human benefit. The animal welfare ethic, however, is normatively inadequate because it exaggerates the ethical importance of personhood. Because of this, it allows us to justify killing badgers, and might even justify the infliction of considerable suffering if by so doing there is a good chance that economic benefits will accrue. As a result, a deontological position, where animals are accorded the protection of rights, seems a much more promising alternative to utilitarianism. The adoption of any variety of animal rights would render badger culling morally illegitimate. 相似文献
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Tushaar Shah 《Natural resources forum》2000,24(3):197-209
This paper explores a large-scale and growing popular movement to augment groundwater recharge in the Saurashtra region of western India, an area that has been facing acute water scarcity and other associated problems. As a social phenomenon, the movement is at an early stage of its development. However, it is interesting to study it for many reasons. First, even a decade after it began, it is still growing in scale and following. Second, it is entirely spontaneous and internally driven, necessitating no public resources or support. Third, early indications are that its social and ecological impacts are beneficial and highly significant. Fourth, the movement was catalysed and spearheaded by spiritual and religious institutions, which made ingenious use of non-economic messages and motivators in forging a new natural resource ethic based on a broad, collective rationality among movement members. It appears, however, that beyond a threshold, the movement acquired a logic and energy of its own which might fuel its future sustainability and growth. Finally, the movement has important lessons to offer because mobilising social energy on such a scale and intensity can perhaps be one of most effective responses to many of the environmental challenges the world faces today. 相似文献
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Control of landscape diversity by catastrophic disturbance: A theory and a case study of fire in a Canadian boreal forest 总被引:3,自引:0,他引:3
A landscape may be envisioned as a space partitioned by a number of ecosystem types, and so it conforms to a neo-Clementsian model of succession. A corollary is that intermediate disturbance rates should maximize landscape (beta) diversity. This was confirmed using eight boreal forest landscapes in northwestern Ontario, Canada, where intermediate rates of forest fire were associated with highest landscape diversity. Because current measures of evenness subsume a richness measure, it is not, as yet, feasible to assess the relative contributions of evenness and richness to biological diversity, and thus it was not possible to determine the roles of numbers of habitat types and relative amounts of habitat types in the above situation. Both theory and observations suggest that forest fire control in fire-prone landscapes increases landscape diversity, but that it is lowered by fire control in landscapes of intermediate to low diversity. 相似文献
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Stephen Michael Dark 《Journal of Environmental Planning and Management》2017,60(12):2122-2132
The precautionary principle is regularly cited in cases that involve development in eco-sensitive locations. We investigated whether the precautionary principle provides the basis for a coherent framework to prevent environmental harm, and does it work in practice? We suggest that, in principle, the precautionary principle makes good sense. In practice, however, it is imprecise in policy and law and fails to fulfil its promise because it is loosely defined and thus lacks substance and clarity. Consequently, it operates in a framework that is ambiguous, leaving it open to manipulation by discretionary powers. To counter such deficiencies, human-induced environmental harm should be formally observed as ‘criminogenic’ and environmental protection prioritised against which other competing priorities (e.g., ‘year on year’ economic growth) are measured. This would overcome the politico-legal obfuscation and contestations of climate change policy that currently impedes the precautionary principle's practical application. 相似文献
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Michael Allingham 《Resources Policy》1985,11(1):43-48
This article examines the role of futures markets in schieving economic efficiency. The question is introduced in a timeless, certain framework, and extended to the case where time, but not uncertainty, becomes important: it is shown that in such a framework futures markets ensure economic efficiency. Uncertainty is then introduced, and it is shown that contingent markets ensure full efficiency, but that these are cumbersome; it is also shown that futures markets, as an alternative, ensure approximate efficiency. An appendix explores more formally the relation between markets and efficiency. 相似文献
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Robert D. Gibbons 《Journal of the American Water Resources Association》2003,39(4):841-849
ABSTRACT: A statistical approach for making Total Maximum Daily Load (TMDL) impairment decisions is developed as an alternative to the simple tally of the number of measurements that happen to exceed the standard. The method ensures that no more than a small (e.g., 10 percent) percentage of water quality samples will exceed a regulatory standard with a high level of confidence (e.g., 95 percent). The method is based on the 100(1‐α) percent lower confidence limit on an upper percentile of the concentration distribution. Advantages of the method include: (1) it provides a direct test of the hypothesis that a prespecified percentage of the true concentration distribution exceeds a regulatory standard, (2) it is applicable to a wide variety of different statistical concentration distributions, (3) it directly incorporates the magnitude of the measured concentrations unlike traditional approaches, and (4) it has explicit statistical power characteristics (i.e., what is the probability of missing an environmental impact). Detailed study of the simple tally approach reveals that it achieves high statistical power at the expense of unacceptably high false positive rates (30 to 40 percent false positive results). By contrast, the statistical approach results in similar statistical power while achieving a nominal false positive rate of 5 percent. 相似文献
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《International Journal of Green Energy》2013,10(4):451-465
Abstract Exergy can play a key role in developing appropriate and beneficial energy-related policies relating to education and awareness. Two main areas where exergy can have an impact on policies are discussed in this article: public education and awareness and student education. The former is more general, but is supported by the latter. Regarding public education and awareness about exergy, it appears that the public is often confused when it discusses energy, and needs to be better educated about exergy if energy issues and problems are to be addressed appropriately. Regarding the education of students about exergy, it appears that the coverage of exergy in thermodynamics education is often insufficient and inappropriate. Better coverage of exergy is needed to improve thermodynamics education and to make it more interesting to students, and a basic level of “exergy literacy” is needed among engineers and scientists—particularly those involved in decision making. 相似文献
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Theoretically, a resource rent tax is neutral in that it does not influence the allocation of resources. However, the application of such fundamental principles in the tax formula of the South African gold mining industry negates the neutrality principle. A progressive element in the tax rate encourages mining of submarginal ores - leads to misallocation of resources. However, it substantially reduces the financial risks of a mining company engaged in the extraction of a commodity characterized by price volability, such as gold, and permits economies of scale in mining and encourages conservation of a non-renewable resource. As long as prices increase faster than costs, the advantages of this system probably exceed the disadvantages. The choice of the threshold rate in such a tax system is critical. If it is too high it will encourage mining of submarginal ores, and if too low it does not recognize the peculiar risks of gold mining investments. 相似文献