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981.
982.
983.
Recycling wastewater seems to have become a highly useful technique for meeting the shortage of fresh water in all parts of the world. It seems all the more important for Muslim countries because a large number of these countries face acute fresh water shortage. This paper views the problem from an Islamic viewpoint, that is, in the light of the Qur'n, theSunnah, andFiqh works.In Islamic law, water is classified into three categories oftahr,thir, andmutanajjis. The last two categories can be transmuted intotahr water and thus may be used for all mundane as well as religious purposes if they are assimilated into the overall supply oftahr water. This would be lawful from the Islamic viewpoint even without treating the water. To make use of modern technology in order to recycle wastewater effluents after treatment seems quite in keeping with the spirit and letter of the Islamic teachings. 相似文献
984.
985.
Under the United States Clean Air Act Amendments of 1977, a class I designation safeguards wilderness areas from the negative
effects of new sources of air pollution. We monitored streamwater chemistry in the class I Lye Brook Wilderness in southwestern
Vermont from May 1994 through August 1995. Stream samples were collected biweekly at nine sampling locations throughout the
wilderness and were analyzed for major cations and anions, dissolved organic carbon, pH, and acid-neutralizing capacity. Eight
of nine sites sampled had mean annual acid neutralizing capacity values below zero. During the study period, decreases in
streamwater acid neutralizing capacity values were caused primarily by SO4
2−. At some sites, however, NO3
− and naturally occurring, weak organic acids were seasonally important. During high discharge, the low pH and high concentrations
of inorganic monomeric Al were at levels that are toxic to acid-sensitive aquatic species. Watershed mass balances were calculated
to determine annual gains or losses for measured ions. These budgets indicate that S inputs and outputs were nearly equal,
there was a net loss of base cations, and a net gain in N. How long these watersheds can continue to assimilate additional
N inputs is unknown. 相似文献
986.
Fertilizer Management in Watersheds of Two Ramsar Wetlands and Effects on Quality of Inflowing Water
Two field experiments were carried out in the watersheds of two Ramsar wetland areas, Lakes Koronia and Volvi (area A) and
Lakes Mikri and Megali Prespa (area B), to study the effect of application of N fertilizer on wheat yields, the quality of
runoff water, and the quality of stream water. The treatments were a combination of two methods of fertilizer application
(total amount in fall, and 2/3 in fall + 1/3 in spring) at three rates (0, 100, and 200 kg N/ha) with four replications. Concentrations
of NH4
+, NO3
−, NO2
−, P, and Cl− and pH were determined in all water samples. Runoff water quality was not influenced by fertilizer application in either
area. Chemical parameters for water did not differ along the selected watercourses in area B, while in area A they were higher
in the samples taken near Lake Koronia than in the samples taken upstream, indicating that the watercourses are polluted downstream
by nonagricultural sources. The differences in wheat yields between the 100 and 200 kg N/ha application rates were not high.
These results call for better fertilizer management in order to achieve better yields and to diminish the possibility to have
negative effects to the environment. 相似文献
987.
Remediation of contaminated land and groundwater is of common international concern. The context and approach taken to the problem are, however, country-specific. A survey of remedial activity occurring within England and Wales over the period 1996-1999 was commissioned by the Environment Agency (for England and Wales) to establish a baseline against which future trends in remedial activity could be judged. This paper: explains the context of contaminated land and groundwater remediation in England and Wales (Britain); provides an overview of the 1996-1999 survey of remedial activity, discussing its findings within its legislative and institutional context; and, discusses the survey results of significance to the management of contaminated land and groundwater internationally. The survey obtained specific data from 367 remediated sites supplemented by general data from a further 1189 contaminated (not necessarily remediated) sites. The survey aimed to be, and was indicative of remediation practice, and did not seek to identify every remediation scheme operating. Previous anecdotal evidences were generally confirmed. Civil engineering-based techniques dominated and were used at 94% of sites with in situ techniques (predominantly vapour extraction-based) on 16% and ex situ on just 5%. Although disposal to landfill was dominant and occurred at over 80% of sites, integrated use of multiple techniques was common. Remediation was predominantly of soil (rather than water), development-based, designed to protect human health and reflected national development-led and 'suitable for use' policies. Lessons of international relevance from the survey and general British experience are drawn concerning remediation technique selection, regulatory and financial support of innovative remediation techniques and demonstration sites, competent use of risk-based approaches to allow pragmatic remediation and effective use of quality guidelines, need for effective guidance to highlight water quality issues, the necessity of post remediation monitoring to prove remediation effectiveness and the keeping of remediation databases. 相似文献
988.
Several writers on animal ethics defend the abolition of most or all animal agriculture, which they consider an unethical exploitation of sentient non-human animals. However, animal agriculture can also be seen as a co-evolution over thousands of years, that has affected biology and behavior on the one hand, and quality of life of humans and domestic animals on the other. Furthermore, animals are important in sustainable agriculture. They can increase efficiency by their ability to transform materials unsuitable for human consumption and by grazing areas that would be difficult to harvest otherwise. Grazing of natural pastures is essential for the pastoral landscape, an important habitat for wild flora and fauna and much valued by humans for its aesthetic value. Thus it seems that the environment gains substantially when animals are included in sustainable agricultural systems. But what about the animals themselves? Objections against animal agriculture often refer to the disrespect for animals’ lives, integrity, and welfare in present intensive animal production systems. Of the three issues at stake, neither integrity nor animal welfare need in principle be violated in carefully designed animal husbandry systems. The main ethical conflict seems to lie in the killing of animals, which is inevitable if the system is to deliver animal products. In this paper, we present the benefits and costs to humans and animals of including animals in sustainable agriculture, and discuss how to address some of the ethical issues involved. 相似文献
989.
N. K. Woodfield J. W. S. Longhurst C. I. Beattie D. P. H. Laxen 《Water, Air, & Soil Pollution: Focus》2002,2(5-6):677-688
Across the United Kingdom, the majority of local authoritieshave now completed their first phase of local air qualityreview and assessment work, as required under the AirQuality Strategy for England, Scotland, Wales and NorthernIreland (DETR, 2000a). Emerging from this first phasework is an anticipated suite of over 110 Air QualityManagement Areas (AQMAs). These areas are identifiedlocations where one or more of the national air qualityobjectives are predicted to exceed by specific target dates,and their spatial extent and shape is emerging as highlyvariable. Local authorities are guided to use a variety ofscientific tools to underpin the scientific assessments, anda consideration of uncertainty in both the tools used andsubsequent delineation of AQMAs is likely to affect theemerging management areas significantly. With subsidiarity underpinning the process of local air qualitymanagement (LAQM), local decision-making is anticipated toinfluence the outcome of the LAQM process in its entirety,with the declaration of AQMAs necessitating the preparationand implementation of air quality action plans. UKexperience of the effective management of local air quality,through the designation of AQMAs, demonstrates a valuableframework for other European countries developing mechanismsto manage air quality locally. 相似文献
990.
Simulations of urban or natural environments created by graphics computer software are increasingly being utilized in research and applied contexts, and pertinent techniques have become highly sophisticated. However, the quality and utility of such presentation means still need careful validation. This issue was addressed in a series of lab and field studies. In the study reported here, a simulation of a suburban environment was presented to respondents (n=147) in several variations to investigate the effects of lighting (day/sun, day/fog, night), personal shadow (yes/no) and sound (on/off) on perceived simulation quality. The contingencies with related aspects (such as comprehension, recollection and appreciation of the simulated environment) were investigated as well. Based on a comprehensive conceptual framework, a set of scales measuring relevant cognitive and affective aspects was employed. Main results are that simulations were perceived as valid and acceptable, that appraisals differ according to lighting and time-of-day conditions, and that provision of sound enhances the perceived quality of presentations. The findings elucidate which factors are crucial for further improving simulations and clarify the validity of computer simulations for assessing existing and future environments. 相似文献