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361.
二氧化碳水合物储气特性的实验研究 总被引:2,自引:0,他引:2
利用二氧化碳水合物小型实验装置分别在恒容和恒压条件下,研究了机械搅拌对二氧化碳气体溶解的影响以及温度与水-气比对二氧化碳水合物形成和储气密度的影响。通过实验结果发现,机械搅拌对二氧化碳的溶解有非常明显的促进作用,可以在3 min内完成溶解过程,促进溶解作用好于添加剂SDS。研究还发现,反应温度越低,二氧化碳水合物的生成速率越快,总的储气量越大,而水-气比越大,储气密度越小。在实验压力3 MPa、反应温度273.55 K的条件下,1体积的水生成水合物后可储存157体积的二氧化碳。 相似文献
362.
氧化镁烟气脱硫反应特性研究 总被引:7,自引:2,他引:5
利用实验室规模的鼓泡式反应装置,对比了碳酸钙、氧化镁和氧化镁/硫酸镁脱硫剂的反应活性,证实脱硫液中高浓度硫酸镁的存在是保证镁法脱硫效率高于钙法的重要因素,并考察了硫酸镁浓度、脱硫剂(氧化镁)浓度、烟气量、SO2浓度和吸收液温度等因素对脱硫效率的影响。结果表明,脱硫反应可以根据pH分为2个不同阶段;反应过程中脱硫效率随着硫酸镁浓度的增加而显著升高;烟气量增加将会导致脱硫效率有所下降;入口SO2浓度升高,脱硫效率下降;氧化镁浓度、温度对脱硫效率影响不显著。结合实验现象进行推断,氧化镁脱硫的反应过程受SO2在气液两相界面的传质扩散和其水解产物在液相的扩散控制。 相似文献
363.
Jorge Rickards 《Journal of environmental radioactivity》2010,101(5):333-337
The functioning of radon diffusion chambers was studied using the Monte Carlo code RAMMX developed here. The alpha particles from radon are assumed randomly produced in the volume of the cylinder, and those from the progeny are assumed to originate randomly at the cylindrical surface. The energy spectrum, the distribution of incident angles, and the distribution of path lengths of the alpha particles on the detector were obtained. These quantities vary depending on input parameters such as initial alpha particle energy, radius and depth of the diffusion chamber, detector size and atmospheric pressure. The calculated energy spectrum for both 222Rn and 220Rn was compared with experiment, permitting the identification of each peak and its origin, and a better understanding of radon monitoring. Three aspects not considered in previous calculations are progeny alphas coming from surfaces of the monitor, taking into account the atmospheric pressure, and including the isotope 220Rn. 相似文献
364.
Ute Rita Thorenz Jaroslava Sobocka 《Environmental pollution (Barking, Essex : 1987)》2010,158(6):2208-2217
We modified an analytical method to determine polybrominated diphenyl ethers (PBDEs) in urban soils of Bratislava (Slovakia). Gel permeation chromatography (GPC) introduced as a clean-up step for soil extracts substantially reduced matrix enhancements when PBDEs were measured with gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS). The resulting method proved to be accurate, precise, and showed low detection limits. The sum of 15 PBDE concentrations in surface horizons of Bratislava soils ranged from 87 to 627 pg g−1. PBDE concentrations were mostly higher in surface than deeper horizons probably because of atmospheric deposition and lack of substantial vertical transport. Lower brominated PBDEs undergo more soil-atmosphere exchanges or are more scavenged and transferred with litter fall to the soil organic matter than higher brominated ones as suggested by the correlation between lower brominated PBDEs and soil organic C (Corg) concentrations. 相似文献
365.
Xiaosong Chang Xiaoyun Liu Hao Chen Zhiqun Qiu Jia Cao 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1444-6108
Sewage samples from 4 hospitals, 1 nursery, 1 slaughter house, 1 wastewater treatment plant and 5 source water samples of Chongqing region of Three Gorge Reservoir were analyzed for macrolide, lincosamide, trimethoprim, fluorouinolone, sulfonamide and tetracycline antibiotics by online solid-phase extraction and liquid chromatography-tandem mass spectrometry. Results showed that the concentration of ofloxacin (OFX) in hospital was the highest among all water environments ranged from 1.660 μg/L to 4.240 μg/L and norfloxacin (NOR, 0.136-1.620 μg/L), ciproflaxacin (CIP, ranged from 0.011 μg/L to 0.136 μg/L), trimethoprim (TMP, 0.061-0.174 μg/L) were commonly detected. Removal range of antibiotics in the wastewater treatment plant was 18-100% and the removal ratio of tylosin, oxytetracycline and tetracycline were 100%. Relatively higher removal efficiencies were observed for tylosin (TYL), oxytetracycline (OXY) and tetracycline (TET)(100%), while lower removal efficiencies were observed for Trimethoprim (TMP, 1%), Epi-iso-chlorotetracycline (EICIC, 18%) and Erythromycin-H2O (ERY-H2O, 24%). Antibiotics were removed more efficiently in primary treatment compared with those in secondary treatment. 相似文献
366.
Nahid Akhtar Hidetoshi Inada Taisuke Kondo 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1763-1767
To clarify the effects of O3 on crop plants cultivated in Bangladesh, two Bangladeshi wheat cultivars (Sufi and Bijoy) were grown in plastic boxes filled with Andisol and exposed daily to charcoal-filtered air or O3 at 60 and 100 nl l−1 (10:00-17:00) from 13 March to 4 June 2008. The whole-plant dry mass and grain yield per plant of the two cultivars at the final harvest were significantly reduced by the exposure to O3. Although there was no significant effect of O3 on stomatal diffusive conductance to H2O of flag leaf, net photosynthetic rate of the leaf was significantly reduced by the exposure to O3. The sensitivity of growth, yield, yield components and leaf gas exchange rates to O3 was not significantly different between the two cultivars. The results obtained in the present study suggest that ambient levels of O3 may detrimentally affect wheat production in Bangladesh. 相似文献
367.
Pakistan is facing problem of deforestation. Pakistan lost 14.7% of its forest habitat between 1990 and 2005 interval. This paper assesses the present forest wood consumption rate by 6000 brick kilns established in the country and its implications in terms of deforestation and emission of greenhouse gases. Information regarding consumption of forest wood by the brick kilns was collected during a manual survey of 180 brick kiln units conducted in eighteen provincial divisions of country. Considering annual emission contributions of three primary GHGs i.e., CO2, CH4 and N2O, due to burning of forest wood in brick kiln units in Pakistan and using IPCC recommended GWP indices, the combined CO2-equivalent has been estimated to be 533019 t y−1. 相似文献
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综述了2009年我国机动车污染防治行业的发展环境及市场特点、主要(骨干)企业发展情况,分析了2009年行业发展中存在的主要问题,提出了解决对策和建议,并对行业的发展进行了展望。 相似文献