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61.
SO2是产生酸雨的主要气体,其主要来源于工业燃煤锅炉。以沈阳一家电厂为例,该厂选用新型高效的喷淋泡沫脱硫除尘器对锅炉排放的SO2进行治理。进入喷淋泡沫塔前的SO2平均浓度为2780mg/m^3,经脱硫后出塔平均浓度为289.3mg/m^3,去除率为89.6%。结果表明,这种有别于传统湿法的新型高效的喷淋泡沫脱硫技术及装置具有脱硫效率高、装置占地少、运行稳定、沉淀物易于回收利用等特点,对锅炉排放的SO2进行治理是非常有效的。 相似文献
62.
焚烧秸秆对城市空气质量的影响及对策 总被引:10,自引:0,他引:10
通过夏收季节农民焚烧秸秆的烟尘,引起对城市环境空气质量变化的分析,结果表明:焚烧秸秆对城市环境空气质量有很大影响,使环境空气质量明显下降,而主要污染物为可吸入颗粒物PM10。有关部门应采取有效措施,禁止焚烧秸秆,同时应积极为农民寻找合理利用秸秆的途径,减少对城市空气的烟尘污染。 相似文献
63.
不同粒度飞灰中16种微量元素的含量分布 总被引:7,自引:0,他引:7
研究了不同粒级的燃煤飞灰中的Ba、Be、Cd、Cr、Cu、Hg、Li、Mn、Ni、Pb、Sr、Ti、V、Zn、Zr元素的含量分布,煤中元素的含量比及富集因子。 相似文献
64.
Peng Xu Junke Zhang Dongsheng Ji Zirui Liu Guiqian Tang Changsheng Jiang Yuesi Wang 《环境科学学报(英文版)》2018,30(1):16-27
In this study, we performed a highly time-resolved chemical characterization of nonrefractory submicron particles(NR-PM_1) in Beijing by using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer(HR-ToF-AMS). The results showed the average NR-PM_1 mass concentration to be 56.4 ± 58.0 μg/m~3, with a peak at 307.4 μg/m~3. Due to the high frequency of biomass burning in autumn, submicron particles significantly increased in organic content, which accounted for 51% of NR-PM_1 on average. Secondary inorganic aerosols(sulfate + nitrate + ammonium) accounted for 46% of NR-PM_1, of which sulfate,nitrate, and ammonium contributed 15%, 20%, and 11%, respectively. To determine the intrinsic relationships between the organic and inorganic species, we used the positive matrix factorization(PMF) model to merge the high-resolution mass spectra of the organic species and NO+and NO_2~+ions. The PMF analysis separated the mixed organic and nitrate(NO+and NO_2~+) spectra into four organic factors, including hydrocarbon-like organic aerosol(HOA), oxygenated organic aerosol(OOA), cooking organic aerosol(COA), and biomass burning organic aerosol(BBOA), as well as one nitrate inorganic aerosol(NIA) factor. COA(33%) and OOA(30%) contributed the most to the total organic aerosol(OA) mass, followed by BBOA(20%) and HOA(17%). We successfully quantified the mass concentrations of the organic and inorganic nitrates by the NO+and NO2+ions signal in the organic and NIA factors. The organic nitrate mass varied from 0.01-6.8 μg/m~3, with an average of 1.0 ±1.1 μg/m~3, and organic nitrate components accounted for 10% of the total nitrate mass in this observation. 相似文献
65.
森林火灾是一种破坏性极强的灾害,它与农事活动以及气象条件密切相关,加强其预防与控制具有十分重要的作用和意义。根据2014年~2015年闽东屏南县进行的60次林缘计划烧除试验观测的主要气象要素数据(天晴日数、温度、湿度、风速),建立基于Logistic二元回归的林缘烧除气象条件判别模型进行检验和分析。结果表明,模型判别计划烧除成功与否的预报准确率高(91.7%),主要气象要素对林缘计划烧除成功与否发挥重要作用,其中连续晴天日数为最大影响因子,其次为风速。模型通过检验和验证结果显著,具有预报服务应用价值。 相似文献
66.
67.
Estimating emissions from crop residue open burning in China based on statistics and MODIS fire products 总被引:1,自引:0,他引:1
With the objective of reducing the large uncertainties in the estimations of emissions from crop residue open burning, an improved method for establishing emission inventories of crop residue open burning at a high spatial resolution of 0.25°× 0.25° and a temporal resolution of1 month was established based on the moderate resolution imaging spectroradiometer(MODIS) Thermal Anomalies/Fire Daily Level3 Global Product(MOD/MYD14A1). Agriculture mechanization ratios and regional crop-specific grain-to-straw ratios were introduced to improve the accuracy of related activity data. Locally observed emission factors were used to calculate the primary pollutant emissions. MODIS satellite data were modified by combining them with county-level agricultural statistical data, which reduced the influence of missing fire counts caused by their small size and cloud cover. The annual emissions of CO_2, CO, CH_4,nonmethane volatile organic compounds(NMVOCs), N_2O, NO_x, NH_3, SO_2, fine particles(PM2.5),organic carbon(OC), and black carbon(BC) were 150.40, 6.70, 0.51, 0.88, 0.01, 0.13, 0.07, 0.43,1.09, 0.34, and 0.06 Tg, respectively, in 2012. Crop residue open burning emissions displayed typical seasonal and spatial variation. The highest emission regions were the Yellow-Huai River and Yangtse-Huai River areas, and the monthly emissions were highest in June(37%).Uncertainties in the emission estimates, measured as 95% confidence intervals, range from a low of within ±126% for N_2O to a high of within ± 169% for NH_3. 相似文献
68.
众多手烧型锅炉和工业炉窑废气排放是造成城市空气严重污染的主要原因。本文通过剖析燃煤产生烟尘的机理,现有烟尘控制技术以及不同炉窑的工艺情况,提出手烧型燃煤锅炉、工业炉窑烟尘污染防治措施。 相似文献
69.
Production of boundary layer ozone from tropical American Savannah biomass burning emissions 总被引:1,自引:0,他引:1
Eugenio Sanhueza Paul J. Crutzen Enmanuel Fernndez 《Atmospheric environment (Oxford, England : 1994)》1999,33(30):5819
Boundary layer ozone and carbon monoxide were measured at a savannah site in the Orinoco river basin, during the dry and wet seasons. CO and O3 concentrations recorded around noontime show a good linear correlation, suggesting that the higher ozone levels observed during the dry season are photochemically produced during the oxidation of reactive hydrocarbons in the presence of NOx both emitted by biomass burning. The rate of photochemical ozone production in the boundary layer ozone by biomass burning calculated from the production ratio ΔO3/ΔCO (0.17±0.01 v : v) and the amount of CO produced by fires (0.26–1.3 mole m−2 dry season−1), ranges from 0.6 to 2.6 ppbv h−1 for 8 h of daylight. This O3 production rate is in fairly good agreement with the value derived from RO2 radical measurements made in the Venezuelan savannah during the dry season. The net boundary layer production of O3 from all tropical America savannah fires is estimated to range between 0.28 and 0.36 Tmol O3 per year, which is about 3 times higher than the O3 produced from pollution sources in the eastern United States during the summer. An extrapolation to all of the world's savannah would indicate a net boundary layer ozone production of about 1.2 Tmol yr−1. This is discussed in the context of the overall global budget of tropospheric ozone. 相似文献
70.
An overview of the application of organic geochemistry to the analysis of organic matter on aerosol particles is presented
here. This organic matter is analyzed as solvent extractable bitumen/ lipids by gas chromatography-mass spectrometry. The
organic geochemical approach assesses the origin, the environmental history and the nature of secondary products of organic
matter by using the data derived from specific molecular analyses. Evaluations of production and fluxes, with cross-correlations
can thus be made by the application of the same separation and analytical procedures to samples from point source emissions
and the ambient atmosphere. This will be illustrated here with typical examples from the ambient atmosphere (aerosol particles)
and from emissions of biomass burning (smoke).
Organic matter in aerosols is derived from two major sources and is admixed depending on the geographic relief of the air
shed. These sources are biogenic detritus (e.g., plant wax, microbes, etc.) and anthropogenic particle emissions (e.g., oils,
soot, synthetics, etc.). Both biogenic detritus and some of the anthropogenic particle emissions contain organic materials
which have unique and distinguishable compound distribution patterns (C14-C40). Microbial and vascular plant lipids are the dominant biogenic residues and petroleum hydrocarbons, with lesser amounts
of the pyrogenic polynuclear aromatic hydrocarbons (PAH) and synthetics (e.g., chlorinated compounds), are the major anthropogenic
residues.
Biomass combustion is another important primary source of particles injected into the global atmosphere. It contributes many
trace substances which are reactants in atmospheric chemistry and soot paniculate matter with adsorbed biomarker compounds,
most of which are unknown chemical structures. The injection of natural product organic compounds into smoke occurs primarily
by direct volatilization/steam stripping and by thermal alteration based on combustion temperature. Although the molecular
composition of organic matter in smoke particles is highly variable, the molecular tracers are generally still source specific.
Retene has been utilized as a tracer for conifer smoke in urban aerosols, but is not always detectable. Dehydroabietic acid
is generally more concentrated in the atmosphere from the same emission sources. Degradation products from biopolymers (e.g.,
levoglucosan from cellulose) are also excellent tracers. An overview of the biomarker compositions of biomass smoke types
is presented here. Defining additional tracers of thermally-altered and directly-emitted natural products in smoke aids the
assessment of the organic matter type and input from biomass combustion to aerosols. The precursor to product approach of
compound characterization by organic geochemistry can be applied successfully to provide tracers for studying the chemistry
and dispersion of ambient aerosols and smoke plumes.
Presented at the 6th FECS Conference on Chemistry and the Environment, Atmospheric Chemistry and Air Pollution, August 26–28,
1998, Copenhagen. 相似文献