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151.
杨华国 《再生资源与循环经济》2012,5(10):21-24
嘉兴市地处长三角中心地带,是浙江电子废弃物的重要集散地之一。通过公众调查发现,嘉兴市电子废弃物产生量比较大,而现有电子废弃物回收体系主要是民间个体回收,公众对这种回收渠道的危害后果认知不足,从而造成正规回收渠道的回收困局。因此,应该借鉴浙江永康再生资源回收体系建设的经验,对个体户回收进行改造,并加强公众环保教育,建立合理责任承担机制,从而建设一套高效、环保和健康的电子废弃物回收体系。 相似文献
152.
David T. Welsh 《Chemistry and Ecology》2013,29(5):321-342
Benthic macrofaunal populations through their feeding, bioturbation, burrow construction and sediment irrigation activities have profound influences on organic matter inputs to marine sediments (biodeposition) and on the vertical distribution of deposited organic matter within the sediment. These effects in turn influence the rates and pathways of organic matter mineralisation, and element cycles. Similarly, bioturbation, burrow construction and burrow irrigation are major determinants of sediment-water column fluxes of oxygen and nutrients. In this review, I discuss the influences of the different benthic macrofaunal feeding (functional) groups on mineralisation processes and sediment-water column fluxes of particulate and dissolved nutrients. How these effects influence diagenic processes, the balance between aerobic and anaerobic processes, and the redox status of the surficial sediments. Finally, I discuss some of the limitations of the predominantly laboratory techniques which have been used to study “macrofaunal effects” and how this hinders the inclusion of the effects in quantitative sediment biogeochemical models. 相似文献
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主要介绍宝钢集团浦钢搬迁罗泾工程为建设绿色环保、高效节能、资源循环利用的现代清洁炼钢厂所采用的工艺技术、技术装备和技术措施。对炼钢工程中所采用的各种工艺技术、技术装备和技术措施等进行说明和分析。 相似文献
155.
介绍计算机废弃物的来源、组成、污染,重点阐述了计算机废弃物的拆卸技术和塑料、线路板、贵金属的回收利用方法。对计算机废弃物处理有重要的参考借鉴价值。 相似文献
156.
Information on benthic carbon mineralization rates is often derived from the analysis of oxygen microprofiles in sediments. To enable a direct comparison of different sediment environments, it is often desirable to characterize sediments by a single proxy that expresses their “reactivity” towards oxygen. For this, there are three commonly used proxies: the oxygen penetration depth (OPD), the oxygen flux at the sediment-water interface (DOU), and the maximum volumetric oxygen consumption rate (Rmax). The OPD can be directly determined from the oxygen depth profile, while the DOU is usually obtained by a linear fit to the oxygen gradient either in diffusive boundary layer. The oxygen consumption rate Rmax requires the fitting of a reactive-transport model to the data profile. This article shows that the OPD alone is a suboptimal proxy, because it shows a strong dependence on the half-saturation constant Ks, and secondly, because it is sensitive to the particular re-oxidation conditions right above the oxic-anoxic interface. Similarly, the volumetric oxygen consumption rate Rmax is rather strongly dependent on the kinetic model formulation employed. To show this we fitted three different (Bouldin, Blackman and Monod) kinetics to the same oxygen data profiles. When fitting these models, the Rmax values obtained differed by 20% for exactly the same oxygen profile. Accordingly, if one reports Rmax values, it is crucial to specify the kinetic model alongside. Overall, DOU emerges as sediment reactivity proxy which is the least model dependent. 相似文献
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Gregor Ollesch Valery Demidov Mitrofan Volokitin Michael Voskamp Gudrun Abbt-Braun Ralph Meissner 《Agriculture, ecosystems & environment》2008,126(3-4):229-242
The water quality of the Volga catchment, Russia, is diminished and major nutrients reach critical levels. Proper management strategies depend on process knowledge about nutrient sources and pathways as well as appropriate models. For the 18.8 km2 experimental catchment Lubazhinkha, 100 km south of Moscow, a monitoring scheme was conducted to identify runoff generation and nutrient source areas. The grey forest soils of the catchment are utilized with arable land and pasture (54%) and forest areas. The received results show a high intra-annual and inter-annual dynamic of the snowmelt runoff generation as major hydrological process. Overall sediment export rates during the 3 years of snowmelt investigation from 2003 to 2005 are low with a maximum of 0.33 t ha−1 during snowmelt period 2005 and effectively reduced by a dam at the catchment outlet. Also, the total phosphorus loss from the catchment is low reaching from 0.03 to 0.35 kg ha−1 during the snowmelt periods. However, sediment and total phosphorus concentrations vary within one snowmelt event and can reach high concentrations. Detailed analysis of element concentrations during snowmelt events allows an identification of different flow components and runoff generating mechanisms. During low flow situations phosphorus and dissolved organic carbon are transferred from the arable soils with slow flow components to the channel. In contrast to this situation, the sources of sediment and nutrients split up temporarily and spatially during high flow situations. Aside arable fields that are source of sediment and phosphorus during snowmelt episodes, the forested areas were detected as major source for the export of dissolved organic carbon with surface runoff. In particular these areas are characterized by a late thawing of the topsoil which causes a delayed peak of dissolved organic carbon concentration. The awareness of the dynamic and complex catchment reaction during snowmelt events is of importance for the development of proper management strategies. 相似文献
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