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211.
上海市空气中NOx的污染现状及分担率   总被引:4,自引:0,他引:4  
借鉴国外计算模型和方法,结合调查统计与现场测试,开展了上海市NOx排放的系统研究。结果表明:1998年上海市各类固定源和流动源共排放NOx37.7万t,其中工业固定源排放占总量的71%;在中心城区,机动车排放已成为NOx污染的主要来源,占该地区机动车和固定源排放总量的74%。  相似文献   
212.
蒋利桥  赵黛青  何立波 《环境科技》2006,19(3):17-19,23
综合分析了含氧替代燃料的来源、成份和燃烧后尾气排放特性.着重阐述了含氧替代燃料应用中污染物排放特点:虽然含氧替代燃料燃烧过程中二氧化硫、一氧化碳、炭氢化合物和煤烟等常规污染物排放明显降低,但醇和醛类等非常规污染物排放会明显增加,这些非常规污染物的排放及环境影响在国内还没有引起足够的重视,需要对含氧替代燃料应用过程中非常规污染物的排放特性及抑制机理进行更深入的研究。  相似文献   
213.
应用公共经济学的理论和国内外的实证数据对我国城市污水与垃圾处理市场化前景进行了分析研究.并对制约城市污水与垃圾处理市场化的因子进行了研究,指出我国城市污水与垃圾处理具有相当的芾场化前景:而投资渠道单一、运营管理效率低下、收费政策不够完善是城市污水与垃圾处理市场化程度低的突出问题。最后.针对性地提出了加快我国城市污水与垃圾产业化和市场化的BOT融资模式、排污收费和公众参与等对策。  相似文献   
214.
Green fluorescent protein (GFP) was first isolated in the early 1970s for experimental use from coelenterates or the Pacific jellyfish. Aequorea victoria (Morin and Hastings, 1971). GFP has since become a favored biomarker in the photophysical analysis of molecular and cell biology because of its strong intrinsic visible fluorescence and the feasibility of fusing it to other proteins without affecting their normal functions (Creemers et al., 2000). Here we report using Bacillus subtilis expressing GFP to evaluate the influence of different environmental pH conditions on GFP fluorescence. Emission acquisitions were configured to excite at 471 nm and detect at an emission from 490 to 650 nm at 1-nm increments. Fluorescence intensity was significantly better at pH 7 (4.2 x 105 cps; P-value < 0.01) than at acid or alkaline conditions. GFP is a good biomarker for environments near netural conditions: however, GFP may be unsuitable where soils or waters are below or above pH 7 because of loss in fluorescence intensity. Alternative fluorescent markers and delivery systems must be examined in different environments to optimize responses from bioreporter molecules.  相似文献   
215.
While emission rates of volatile organic compounds (VOCs) have been obtained for building materials, furnishings and processes in chambers, field measurements are more difficult. Procedures to estimate emission rates using transient analysis of VOC concentrations are described and applied in a two-story classroom/office building. The analysis employs semi-real-time VOC concentrations determined with a portable GC/FID and simultaneous air change rate measurements using tracer gas decay. The results of the analysis yield consistent values of emission rates for building materials ranging from 0.20 to 0.40 mg m−2 h−1 when normalized by floor area. Occupancy-related emissions were more difficult to estimate and covered a wider range from roughly 0.1 to 1.5 mg m−2 h−1. The test data were also analyzed in an attempt to determine sink parameters, but these efforts were not particularly successful. Furthermore, in these tests, the inclusion of sink effects did not significantly impact the estimated emission rates. While this paper offers a transient analysis approach that may lead to improved field estimates of VOC emission rates, it is not presented as a definitive methodology. Nevertheless, transient analysis has potential for use in other buildings, but simultaneous air change rate measurements are critical in its application in estimating VOC emission rates in the field.  相似文献   
216.
Total column abundances of CO, HCN, C2H6, and C2H2 have been retrieved from infrared solar spectra observed at Moshiri (44.4°N) and Rikubetsu (43.5°N) in northern Japan from 1997 to 2005. The spectra were recorded with high spectral resolution ground-based Fourier transform infrared (FTIR) spectrometers and total column abundances were calculated by SFIT1 version 1.09e. Deviations of these species relative to their seasonal mean values (ΔCO, ΔHCN, ΔC2H6, and ΔC2H2) were derived, which showed short-time enhancements in 1998, 2002, and 2003. Good correlations among ΔCO, ΔHCN, ΔC2H6, and ΔC2H2 in a few months of each year were seen. Since the number of forest fires in Siberia had large enhancements in 1998, 2002, and 2003, trajectory analyses were performed in order to assess the influence of forest fires and it was confirmed that air masses passing over the location of burning points in Siberia reached Moshiri and Rikubetsu. This paper shows that enhancements of these species were driven by biomass burning in Siberia.  相似文献   
217.
Most environmental professionals and decision-makers, and certainly the public at large, hold the view that the integrity of earth’s natural environment will be conserved for posterity and sustainable development achieved if all the nations rigorously enforced their environmental and emission standards. It is argued in this paper that this view, sincerely held by many as an “axiomatic truth,” is mistaken and misplaced. This is because as a biogeochemical entity the Earth has limited self-regenerative capacity (SRC) to cope with anthropogenic pollution, and all kinds of environmental problems ensue when that limit is exceeded. Indeed, mounting environmental problems now occurring on all fronts amply testify to the fact that the limit has already been exceeded. They also provide necessary and sufficient proof that environmental and emission standards have been woefully inadequate for protecting earth’s natural environment and life-support systems. It is argued that true global environmental sustainability will be achieved, paving the way to true global sustainable development, if and only if global environmental and emission standards are set so that global anthropogenic pollution does not exceed the limit of earth’s natural SRC to cope with such pollution. These and related issues are discussed in this paper. A simple mathematical model using basic mathematics is also presented to explain how the phenomenon of “positive feedback” works in some of the environmental problems to exacerbate environmental degradation and progressively to erode nature’s SRC.
Bhaskar NathEmail:
  相似文献   
218.
大连地区生态植被所排放VOC的估算研究   总被引:2,自引:0,他引:2  
根据实测的太阳总辐射在全波段的辐射照度Q(Wm^-2)估算出光合有效辐射照度UPAR(μmolm^-2S^-1),利用各类植物的排放因子,估算出大连地区生态植被所排放的VOC,结果表明,生态植被所排放VOC的日变化规律即与植物本身有关又与气温和太阳辐射有关,区域内年排放VOC的总量为256.5t。  相似文献   
219.
Selective catalytic reduction (SCR) denitration may increase the emission of NH4+ and NH3. The removal and transformation characteristics of ammonium sulfate aerosols and ammonia slip during the wet flue gas desulfurization (WFGD) process, as well as the effect of desulfurization parameters, were investigated in an experimental system equipped with a simulated SCR flue gas generation system and a limestone-based WFGD system. The results indicate that the ammonium sulfate aerosols and ammonia slip in the flue gas from SCR can be partly removed by slurry scrubbing, while the entrainment and evaporation of desulfurization slurry with accumulated NH4+ will generate new ammonium-containing particles and gaseous ammonia. The ammonium-containing particles formed by desulfurization are not only derived from the entrainment of slurry droplets, but also from the re-condensation of gaseous ammonia generated by slurry evaporation. Therefore, even if the concentration of NH4+ in the desulfurization slurry is quite low, a high level of NH4+ was still contained in the fine particles at the outlet of the scrubber. When the accumulated NH4+ in the desulfurization slurry was high enough, the WFGD system promoted the conversion of NH3 to NH4+ and increased the additional emission of primary NH4+ aerosols. With the decline of the liquid/gas ratio and flue gas temperature, the removal efficiency of ammonia sulfate aerosols increased, and the NH4+ emitted from entrainment and evaporation of the desulfurization slurry decreased. In addition, the volatile ammonia concentration after the WFGD system was reduced with the decrease of the NH4+ concentration and pH values of the slurry.  相似文献   
220.
Continuous observation of isoprene, α-pinene and β-pinene was carried out in a typical urban area of Beijing from March 2014 to February 2015, using an AirmoV OC online analyzer. Based on the analysis of the ambient level and variation characteristics of isoprene, α-pinene and β-pinene, the chemical reactivity was studied, and their sources were identified. Results showed that the concentrations of isoprene, α-pinene and β-pinene in the urban area of Beijing were lower than those in richly vegetated areas; the concentrations of isoprene were at a moderate level compared with those of previous studies of Beijing. Concentrations of isoprene, α-pinene and β-pinene showed different seasonal, monthly, daily and diurnal variations, and all of the three species showed higher level at night than those in the daytime as a whole, the variations of isoprene, α-pinene and β-pinene mainly influenced by emission of sources, photochemical reaction, and meteorological parameters. Isoprene was the largest contributor to the total OFP values than α-pinene and β-pinene. α-Pinene was the largest contributor to the total SOAFP values than isoprene and β-pinene in autumn, while isoprene was the largest one in other seasons. Isoprene, α-pinene and β-pinene were derived mainly from biological sources; and α-pinene level were also affected by industrial sources. To reduce the concentrations of isoprene, α-pinene and β-pinene, it is necessary to scientifically select urban green plant species, and more strict control measures should be taken to reduce the emission of α-pinene from industrial sources, such as artificial flavors and resins synthesis processes.  相似文献   
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