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111.
垃圾填埋场微生物气溶胶粒径分布研究 总被引:4,自引:0,他引:4
为了了解垃圾填埋场微生物气溶胶粒径分布规律,在北京市某垃圾卫生填埋场填埋区、渗滤液处理区、生活区分别选定监测点,利用安德森六级微生物采样器,对填埋场空气微生物进行了系统的定点取样、测定和分析。研究结果表明,空气细菌粒径分布均为第Ⅰ级(>8.2 μm)最高,填埋区空气细菌粒径呈偏态分布,渗滤液处理区、生活区分别在第Ⅳ级和第Ⅲ级出现第2个峰值。携带细菌的可吸入微粒在渗滤液处理区比例最大。空气真菌与放线菌均在第Ⅳ级分布最高,携带真菌和放线菌的可吸入粒子的比例显著大于细菌(P<0.05)。填埋区不同作业时段空气微生物粒径在各级分布比例基本一致。填埋区细菌气溶胶中值直径为5.7 μm,渗滤液处理区为3.7 μm,生活区为5.3 μm,显著大于真菌气溶胶和放线菌气溶胶的中值直径(P<0.05)。 相似文献
112.
六自由度气锤振动与电磁斜面振动是两种模拟产品三轴振动的振动技术。由于两种振动技术的机理不同,其对样品的振动影响也会有区别。本文研究讨论两种不同振动技术的不同特点,以及对不同产品的振动效果别,我们可以根据样品特点和测试需求,选择更合适的震动技术。 相似文献
113.
OHS风险控制方法在烟气排放控制工程中的应用 总被引:1,自引:0,他引:1
介绍了烟气排放控制工程中OHS风险控制的方法,并以香港青山“B”电厂4X680MW机组排放控制工程(CPBEC)为例,阐述了目前国内外环保项目在OHS风险管理方面的差距和改进措施。 相似文献
114.
Rolf Groeneveld Lex Bouwman Sonja Kruitwagen Ekko van Ierland 《Environmental Modeling and Assessment》2001,6(2):101-109
Nitrate leaching forms an important environmental problem because it causes pollution of groundwater and surface water, and adds to already problematic eutrophication. This study analyses the impact of reductions in nitrate leaching on land cover decisions of dairy farms, of which the activities make an important contribution to nitrate leaching. As the level of nitrate leaching depends on groundwater depth as well as on the supply of nitrogen, spatial variation in groundwater levels will cause a spatial variation in land cover under restrictions on nitrate leaching. A non-linear partial optimisation model for the economic and ecological aspects of the problem were used to show how land cover and dairy farms' financial balances change when nitrate losses are reduced. The model is spatially explicit, and describes nitrate leakage and yields of maize and grass as a function of groundwater depth, including the effects of various grazing systems. The model analyses the decisions of a risk neutral agent who minimises costs under the following constraints: (i) production, feed requirements and mass balances for fodder; (ii) constraints for nitrate leaching. Economic costs are attributed to increased costs of fodder and processing of manure when nitrate restrictions are tightened. An important result of the study is the variation in compliance costs and land cover for maize and grass production brought about by spatial variation in groundwater depth. While the effects are negligible for some shallow groundwater classes, it is extremely difficult in other classes – if not impossible – to obtain the EU standard of maximum admissible losses of 34 kg N ha–1 at low costs. The study shows an important reduction in land cover by maize. 相似文献
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116.
秸秆焚烧对北京市空气质量的影响 总被引:38,自引:8,他引:30
用火焰原子吸收光谱法测试了北京市两个采样点 1 #站 (十三陵站 ,清洁对照点 )和 5#站 (天坛站 ,居民生活区 )1 1 0个大气颗粒物样品中的水溶性钾 ,以表征秸秆焚烧颗粒物。 1 #站水溶性钾的质量浓度年均值为 1 .2 1 μg/m3,其中以1 998年 6月份浓度 (3 .0 7μg/m3)最高 ,是 5月份 (1 .0 2μg/m3)的 3倍 ;5#站水溶性钾的质量浓度年均值为 1 .94μg/m3,6月份 (4 .2 2 μg/m3)最高 ,是 5月份 (1 .97μg/m3)的 2 .1倍。数据分析结果表明 1 998年 6月份麦收季节存在以秸秆焚烧为主的生物质燃烧现象 ,使大气颗粒物中有机碳浓度水平升高 ,并对北京市的空气质量带来负面影响 相似文献
117.
The aim of this work is (1) to discuss approaches and tools to set management goals using operational indicators for coastal management (i.e., indicators that are easy to measure, understand and predict) and validated predictive models and (2) to discuss remedial strategies for sustainable coastal management regarding water quality and the abundance of fish, waterfowl and large aquatic plants. These approaches are exemplified using data from Ringkøbing Fjord, Denmark, which has undergone two major regime shifts during the last decades. This work discusses the changes taken place during the period from 1980 to 2004 (when there are good empirical data). For Ringkøbing Fjord, which is a very shallow, well-oxygenated lagoon dominated by resuspension processes, we have targeted on the following operational indicators, which are meant to reflect seasonal median values for the entire defined coastal area (the ecosystem scale) and not conditions at individual sites or data from shorter time periods: Secchi depth (as a standard measure of water clarity) and chlorophyll-a concentrations (as a key measure of algal biomass). The operational indicators are regulated by a set of standard abiotic factors, such as salinity, suspended particulate matter (SPM), nutrient concentrations (N and P), coastal morphometry and water exchange. Such relationships are quantified using well-tested, general quantitative models, which illustrate how these indicators are interrelated and how they reflect fundamental aspects of coastal ecosystems. We demonstrate that the regime shift in the lagoon can be modelled and quantitatively explained and is related to changes in salinity and nutrient inflow. A very important threshold is linked to increased salinities in the lagoon. For example, when the mean annual salinity is higher than about 9.5‰, large numbers of saltwater species of clams can survive and influence the structure and function of the ecosystem in profound ways. The model also illustrates the dynamic response to changes in nutrient loading. We have presented several management strategies with the goal of keeping the Secchi depth at 2 m, which would stimulate the growth of higher aquatic plants, which are fundamental for fish production and bird abundance in the lagoon. Given the fact that the Secchi depth depends on many variable factors (temperature, TP-inflow from land, salinity, changes in biomasses of macrophytes and clams, which are accounted for in these simulations), our results indicate that in practice it will likely be very difficult to reach that goal. However, it would be realistic to maintain a Secchi depth of 1.5 m if the variability in salinity is minimized and the mean salinity is kept at about 10.2‰. 相似文献
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119.
自上世纪80年代伊始,我国含有多氯联苯的电力电容器等相继进入报废阶段,许多地区采用回收后山洞贮存、地下封存等方式处置,而其他处置方式在我国尚处于初级试验阶段。日本一些企业所采用的多氯联苯处置技术,值得我们学习和借鉴。 相似文献
120.
衔接土地利用规划和建设项目的土地一级开发伴随着土地政策的改革而出现。目前土地一级开发环境影响评价处于起步阶段,缺乏对这项工作系统的研究。本文结合工作中的实践经验,从土地一级开发环境影响评价实施的意义、作用和评价目的等方面对土地一级开发的环境影响评价进行了论述,分析了其环境影响评价存在的问题,总结了土地一级开发环境影响评价的技术要点,并对完善土地一级开发环境影响评价制度提出建议。 相似文献