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461.
Wei Nie Tao Wang Aijun Ding Xuehua Zhou Wenxing Wang 《Frontiers of Environmental Science & Engineering》2014,8(4):553-560
Toxic elements in the atmosphere can enter and accumulate in the human body, seriously impacting human health. In this study, we analyzed a 14-year (1995-2008) measurement of three toxic elements (As, Cd and Cr) in PMlo in Hong Kong, China. The pollution of these toxic elements in Hong Kong was not serious. The trend analysis showed that As and Cr in PM10 increased at a statistically significant level (p〈0.05) during the 14-year period, while the Cd in PM10 did not change significantly. Typical seasonal variations were observed for all three toxic elements, largely in relation to the Asian monsoon. Hourly 10-day backward trajectories were computed and cate- gorised into four groups. The continental air masses showed much higher concentrations of the three toxic elements than the marine air masses. The abundances of As and Cd in the PM10 were much higher in the continental air masses than those in the marine air masses, while the abundances of Cr showed an opposite pattern. The trends of the three toxic elements in East China's air mass were consistent with those in the overall data set ofHong Kong. Examination of the toxic element data recorded at urban sites and a roadside site also indicated a large contribution of external air masses to particulate As and Cd in Hong Kong. These results suggest that the long-range transport from the mainland of China is the dominant contributor to particulate As and Cd, while both local and long-distance sources determine the particulate Cr in Hong Kong. 相似文献
462.
Zhendong Yang Aihua Lv Yulun Nie Chun Hu 《Frontiers of Environmental Science & Engineering》2013,7(3):451-456
Fe3O4 was supported on mesoporous Al2O3 or SiO2 (50 wt.%) using an incipient wetness impregnation method, and Fe3O4/Al2O3 exhibited higher catalytic efficiency for the degradation of 2,4-dichlorophenoxyacetic acid and para-chlorobenzoic acid aqueous solution with ozone. The effect and morphology of supported Fe3O4 on catalytic ozonation performance were investigated based on the characterization results of X-ray diffraction, X-ray photoelectron spectroscopy, BET analysis and Fourier transform infrared spectroscopy. The results indicated that the physical and chemical properties of the catalyst supports especially their Lewis acid sites had a significant influence on the catalytic activity. In comparison with SiO2, more Lewis acid sites existed on the surface of Al2O3, resulting in higher catalytic ozonation activity. During the reaction process, no significant Fe ions release was observed. Moreover, Fe3O4/Al2O3 exhibited stable structure and activity after successive cyclic experiments. The results indicated that the catalyst is a promising ozonation catalyst with magnetic separation in drinking water treatment. 相似文献
463.
The existence of fire whirls in some ship engine room is studied by using the basic elements of the fire whirls formation. The temperature characteristic of fire whirls are used to study the path shift of fire whirls and the result is nearly circular. The center shift angular velocity of fire whirls is analyzed with the least square fitting in the conditions of the constant wind velocity and the variable wind velocity from four sides. In the situation of the constant wind velocity, the result shows that the center shift angular velocity of fire whirls comply with the change regularity of a cube polynomial with different wind speed. When the wind velocity is more than 6.58 m/s, it strongly affects the change rate of the center shift angular velocity. However, in the situation of variable wind velocity, when the change rule of wind velocity follow increasing or descending regularity, the change law of the center shift angular velocity is proportional to the size of the wind velocity, but when the wind velocity is random variation, the change fluctuation of center shift angular velocity is comparatively small. Computational results have important significance for the structure fireproofing, fire evaluation and shipping design. 相似文献
464.
The coal and gas outburst results from plenty of factors, while vibration is the most important factor among them. Therefore, the influences of vibration acting on gas desorption and coal structure had been conducted. And the mechanism of coal and gas outburst induced by vibration was illustrated through examples. The results showed that the gas desorption accelerates under the action of vibration, and then the gas gradient increases. Meanwhile, vibration would increase and expand fractures in the internal coal body, which aggravates the risk of coal and gas outburst greatly. In conclusion, vibration is a more important factor attributable to coal and gas outburst compared with other coal mining method, mining technology and construction method. 相似文献
465.
具体阐述了各式不同种类的脉冲袋式除尘器在水泥厂内针对破碎机、球磨机、干法预分解窑和干法中空窑及原料储存、运输等方面的应用。 相似文献
466.
The current status of the treatment and disposal of hazardous wastes in China is summarized on the basis of the results of
the Declaring and Registration Project initiated nationally in 1995. A principle framework for the sound management of hazardous
wastes is proposed, which includes three levels of technical solutions. Large-scale enterprises are encouraged to recycle,
to treat, and to dispose of wastes by means of constructing facilities, and to have their extra capacities available to the
public for a reasonable fee. Municipal governments, provincial governments, and the Central Government are to plan and construct
centralized facilities to recycle, treat, and dispose of wastes. For a solution at the manufacturing level, recycling is identified
as the main approach. Centralized facilities at the municipal level will mainly focus on special wastes that are unsuitable
to transport and store, such as hospital waste, and for the technical solution at this level, incineration and recycling are
identified as the main approaches. For the technical solution at the provincial and national levels, landfill and incineration
are identified as the main approaches. Based on this principle and the current available data on hazardous wastes, a preliminary
plan for the spatial distribution of cross-provincial centralized treatment and disposal facilities of hazardous wastes is
presented. The construction of approximately nine cross-provincial comprehensive facilities is proposed. A priority list for
the construction of these planned facilities is also presented. 相似文献
467.
对地矿部门近40年的工业卫生工作,包括尘、毒、噪声等有害因素的综合治理,职业病防治,作了简明回顾。对目前的情况进行了分析。对今后工作提出了初步建议及对策。 相似文献
468.
Lu WJ Wang HT Nie YF Wang ZC Huang DY Qiu XY Chen JC 《Journal of environmental science and health. Part. B》2004,39(5-6):871-887
A lab-scale composting experiment was carried out using vegetable and flower stalks waste to study the effectiveness of ligno-cellulolytic microorganisms (LCMs) obtained from the previous isolation on composting process, especially on enhancement of biodegradation rate of these organic materials. The addition of LCMs to compost showed promised to be a valuable asset by rendering timely benefits in efficiency, maturity, and quality of the composting. This was evidenced by a significant increase of temperature, O2 consumption and CO2 emission, and population density of LCMs in compost mass compared with that of biotic (addition of culture of horse feces) and abiotic (1% molasses amendment) treatments, as well as control trial. The phytotoxicity assay showed that the substrate became mature after 60 days' composting. The LCMs inoculation enhanced the biodegradation of the composting materials as evidenced by an increasing screening ratio (1.2 cm sieve pore) of 34.5% in the treated trail, compared with that of control, which elucidated that big advantage of adding selected inoculants over other treatment, and screening ratio is a reasonable index to compare the quality of different compost. However, the inoculation seemed to have no significant effect on the moisture content, pH, and the final organic carbon of the composting materials. 相似文献
469.
自然中心主义环境伦理思想作为目前最为热门的学科之一,自然同其它学科一样,有它产生的思想根源、现实缘由和直接的动因。工业社会的精神失落和蓬勃兴起的绿色运动是其思想诱因与直接动因,而它形成的现实缘由则主要是全球面临的生态困境以及对人与自然关系的重新认识。 相似文献
470.
Health risk assessment of dietary exposure to polycyclic aromatic hydrocarbons in Taiyuan, China 总被引:2,自引:0,他引:2
Sixteen polycyclic aromatic hydrocarbons (PAHs) were determined in 24 duplicate-diet samples from people in Taiyuan during summer and winter in 2009. Dietary intake of PAHs for 2862 participants was subsequently estimated by a survey in Taiyuan. Results from these 24 samples were compared with a raw food study in Taiyuan in 2008. Three main sources of dietary PAHs are vegetables, wheat flour and fruits, the sum of which contributes 75.95% of PAHs in dietary food. Compared to the estimated value in raw food, much more B[a]Peq (benzo[a]pyrene equivalents) were detected in food samples collected in the duplicate-diet study in Taiyuan (60.75 ng/day). The cooking process may introduce more B[a]Peq into food, and the relative contribution of 16 PAHs in the diet would be changed during the cooking procedure. 相似文献