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961.
The aim of this study is to analyze the environmental agenda in Sweden during the last two decades. A content analysis was made of all articles in a Swedish journal,Miljö-Aktuellt. Further, to elucidate the evolutionary process of problem formulation and reformulation, two cases were investigated, dealing with the impact of plant nutrients and mercury on surface water quality. The transport of heavy metals is an essential component of the ecological process and problem of acidification, and similarly, plant nutrients are part of the concept of eutrophication. Two concepts, the research cycle and the policy cycle, are tentatively applied to the conceptualizations of acidification and eutrophication. Additional data for the latter part of the study is supplied from parliamentary motions during 1973–1989. The substance/media focus of the 1970s was connected to a point-source abatement strategy, which mainly aimed at removing negative effects at a local level. The development of a national preventive strategy is traced in problem formulations related to “processes” going on in the technosphere: wastes, noise, energy production, traffic, and toxic substances. This period lasted from the mid-1970s to the mid-1980s, and the need for improved resource management as a means to control environmental problems has been a generally accepted idea. However, this does not mean that measures actually taken are sufficient in a material balance perspective. Further, in the 1980s there was a strong emphasis upon processes in the ecosphere. This focus also implies source-related policies. To a certain extent, the remedies are within the scope of national capabilities, but the international dimension is becoming increasingly important. Scientific proofs of resource and environment degradation are essential to induce political action and to stimulate international cooperation. From this study, however, it is not possible to assess the existence of any particular policy-triggering information. 相似文献
962.
Rising crude oil prices favour the exploitation of hitherto unutilised energy carriers and the realisation of new technologies in all sectors where carbon is used. These changed economic constraints necessitate both savings in conventional petrochemistry and a change to oil-independent carbon sources in the chemical industry. While, in coal chemistry, the synthesis and process principles of petrochemistry — fragmentation of the raw material and subsequent buildup of molecular structures — can be maintained, the raw material structure largely remains unchanged in the chemistry of renewable raw materials. This lecture is to demonstrate the structural as well as the technological and energy criteria of the chemistry of alternative carbon sources, to forecast the chances of commercial realization and to discuss some promising fields of research and development. 相似文献
963.
Bergström L 《Environmental pollution (Barking, Essex : 1987)》1990,67(4):325-347
In this review of lysimeters, different aspects concerning soil-filling technique, lysimeter size and materials, and drainage-system type are discussed. The placement of lysimeters in the field is dealt with, as are other types of field measurements that can provide complementary information. Evaluations of various properties are based on the assumption that the lysimeters are to be used for estimating pesticide leaching. Guidelines for use in designing a suitable lysimeter experiment for this purpose are described, with special emphasis placed on using the results as a basis for pesticide registration. In this context, some general recommendations are identified. Concerning the lysimeter itself, stress is placed on the importance of using undisturbed soil monoliths. It is recommended that two soil types, i.e. sand and clay, be used and that the management practices carried out closely resemble normal farming practices. Further recommendations include weekly water sampling, two watering regimes, and use of the normal and double the normal application rate of pesticides. 相似文献
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965.
Peter Gode 《Chemosphere》1984,13(8):933-938
The loss of chemicals in static fish tests due to biodegradation has been studied with eight model surfactants whose biodegradabilities in the OECD Screening Test range from 0 to 99 % BiAS removal. There was a good correlation between biodegradation in the fish test and in the OECD Screening Test. Only surfactants with a very high BiAS removal of above 93 % were also degraded quickly in the fish test. Surfactants with less than 80 % BiAS removal incurred losses of less than 20 % in the fish test. These results indicate that those substances which are not lost by volatility or adsorption will be maintained to at least 80 % of their nominal concentration during a 96 hour static fish test. 相似文献
966.
967.
Peter F. Larsen Vincent Zdanowicz Anne C. Johnson Lee F. Doggett 《Chemistry and Ecology》1983,1(3):191-200
The concentrations in surface sediments of the trace metals Cd, Cr, Cu, Ni, Pb and Zn have been determined at 32 stations in the Casco Bay region of the Gulf of Maine. The metals are not distributed homogeneously but exhibit elevated levels around the Portland waterfront and generally low levels at offshore and tidally scoured stations. Comparison of these results to those from both industrialized and non-industrialized sites throughout New England indicates that the sediments in parts of the Casco Bay region are affected by trace metals. 相似文献
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