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981.
982.
吹扫捕集-GC-MS测定废水中的硝基氯苯 总被引:1,自引:0,他引:1
建立了吹扫捕集-GC-MS测定水样中硝基氯苯类化合物的方法.考察了吹扫温度、吹扫时间等对吹扫捕集效率和方法检出限的影响.在室温下,当吹扫时间为30 min时,该方法的最低检出限可达0.002 mg/L,工作曲线的线性范围为2×10 -3 ~2 mg/L,相对标准偏差在2%~6%,加标回收率在97.0%~110.0%.与国家标准方法相比,该法具有操作简便、灵敏度高、线性范围宽且无须使用有毒有机溶剂等优点,可满足工业废水和地表水中硝基氯苯的测定要求. 相似文献
983.
Healthy watersheds provide valuable services to society, including the supply and purification of fresh water. Because these natural ecosystem services lie outside the traditional domain of commercial markets, they are undervalued and underprotected. With population and development pressures leading to the rapid modification of watershed lands, valuable hydrological services are being lost, which poses risks to the quality and cost of drinking water and the reliability of water supplies. Increasing the scale and scope of programmes to protect hydrological services requires policies that harmonize land uses in watersheds with the provision of these important natural services. This article summarizes key attributes of hydrological services and their economic benefits; presents a spectrum of institutional mechanisms for safeguarding those services; discusses programmes in Quito (Ecuador), Costa Rica and New York City; and offers some lessons learned and recommendations for achieving higher levels of watershed protection. 相似文献
984.
本文以大量事实论述了上海市由于水质污染,不仅严重威胁着上海市民的身体健康,而且已导致上海市严峻的水荒灾害问题。文章还从历史回顾中论证了上海市在治理水质污染方面的失策,并根据国内外的经验教训,提出了解决上海市水荒同题的对策和建议。 相似文献
985.
Analysis of a rural water supply project in three communities in Mali: Participation and sustainability 总被引:1,自引:0,他引:1
This paper presents a qualitative assessment of the participatory water management strategies implemented at the community level in rural Mali through a water supply project — The West Africa Water Initiative (WAWI) — coordinated by World Vision International, a non‐governmental and humanitarian organization. Data for the study were generated through a combination of primary and secondary sources in three villages. Results of the study indicate that while community‐based rural water supply is a positive step in responding to the needs of rural Malians, the installation of boreholes with hand pumps informed merely by consultative participatory approaches and limited extension involvement will not necessarily proffer sustainable rural water supply in the region. A “platform” approach to rural water supply management that can mobilize the assets and insights of different social actors to influence decision making at all stages, including the design and choice‐of‐technology stages, in water supply interventions is instead advocated. 相似文献
986.
Key aspects of environmental management exist within a legislative framework. The Rivers and Foreshores Improvement Act 1948 (NSW) and several Regional Environmental Plans created under the Environmental Planning and Assessment Act 1979 (NSW) make reference to ‘the top of the bank’ for defining areas of protected land adjacent to rivers, within which development
consent may be required. It is an arbitrary term and its use within the Rivers and Foreshores Improvement Act 1948 (NSW) leads to confusion. This paper examines the range of definitions of ‘the top of the bank’ in respect of natural watercourses
and aims to provide a more lucid and effective definition that will clarify existing ambiguities in legal interpretation.
The paper examines the historical origins of the phrase ‘top of the bank’, finding that stereotyped Eurocentric views of what
a river ‘should look like’ have impaired the legal definition for Australian rivers, thereby influencing common law and the
development of statutory definitions. Judicial applications of the phrase ‘top of the bank’ are examined from a geomorphological
perspective, demonstrating the misconceptions of the term in a legal context. The paper identifies the existence of widespread
support for the need to protect land adjacent to rivers in the interests of environmental, economic and social sustainability.
It concludes by calling for legislative reform that is both tailored to the individual site and consistent with overarching
goals at the catchment scale. 相似文献
987.
Tirusew Asefa Nisai Wanakule Alison Adams 《Journal of the American Water Resources Association》2007,43(5):1245-1256
Abstract: In this paper, a field‐scale applicability of three forms of artificial neural network algorithms in forecasting short‐term ground‐water levels at specific control points is presented. These algorithms are the feed‐forward back propagation (FFBP), radial basis networks (RBN), and generalized regression networks (GRN). Ground‐water level predictions from these algorithms are in turn to be used in an Optimized Regional Operations Plan that prescribes scheduled wellfield production for the coming four weeks. These models are up against each other for their accuracy of ground‐water level predictions on lead times ranging from a week to four weeks, ease of implementation, and execution times (mainly training time). In total, 208 networks of each of the three algorithms were developed for the study. It is shown that although learning algorithms have emerged as a viable solution at field scale much larger than previously studied, no single algorithm performs consistently better than others on all the criteria. On average, FFBP networks are 20 and 26%, respectively, more accurate than RBN and GRN in forecasting one week ahead water levels and this advantage drops to 5 and 9% accuracy in forecasting four weeks ahead water levels, whereas GRN posted a training time that is only 5% of the training time taken by that of FFBP networks. This may suggest that in field‐scale applications one may have to trade between the type of algorithm to be used and the degree to which a given objective is honored. 相似文献
988.
Over-allocation of irrigation water has led to widespread environmental degradation in the Murray-Darling Basin (MDB) in Australia,
prompting discussions of the water efficiency performance of irrigated industries. There is increasing pressure for irrigators
to adopt water efficient practices in line with ecologically sustainable principles, especially with current drought conditions.
However, there is great uncertainty surrounding the available practices to improve irrigation efficiency from both ecological
and economic standpoints. This paper examines the economic and environmental impact of several possible water efficient practices
and government policies, using an interdisciplinary approach combining biophysical modelling and economic modelling. This
is done for the case-study of the Mooki catchment in the MDB, located in northern New South Wales, Australia. 相似文献
989.
The biological removal of phosphates was carried as a part of treatment strategy. Vetiveria zizanioides (L.) Nash belonging to the family Poaceae was used for biological removal of biostimulants. Vetiver reportedly has mycorrhizal
association; besides having potential for removal of PO4
−3 also showed allelopathic affect on the microorganisms present in the water. In fact after a period of 96 h old roots of this
plant have been found to have killing effects on the E. coli, Enterobacter spp. Pseudomonas spp. belonging to the family Enterobacteriaceae. The paper is opening a new face of study. 相似文献
990.