排序方式: 共有34条查询结果,搜索用时 15 毫秒
31.
Harry Freeman Teresa Harten Johnny Springer Paul Randall Mary Ann Curran Kenneth Stone 《Journal of the Air & Waste Management Association (1995)》2013,63(5):618-656
Abstract Pyrolytic product distribution rates and pyrolysis behavior of tire-derived fuels (TDF) were investigated using thermogravimetric analyzer (TGA) techniques. A TGA was designed and built to investigate the behavior and products of pyrolysis of typical TDF specimens. The fundamental knowledge of TGA analysis and principal fuel analysis are applied in this study. Thermogravimetry of the degradation temperature of the TDF confirms the overall decomposition rate of the volatile products during the depolymerization reaction. The principal fuel analysis (proximate and ultimate analysis) of the pyrolytic char products show the correlation of volatilization into the gas and liquid phases and the existence of fixed carbon and other compounds that remain as a solid char. The kinetic parameters were calculated using least square with minimizing sum of error square technique. The results show that the average kinetic parameters of TDF are the activation energy, E = 1322 ± 244 kJ/mol, a pre-exponential constant of A = 2.06 ± 3.47 × 1010 min?1, and a reaction order n = 1.62 ± 0.31. The model-predicted rate equations agree with the experimental data. The overall TDF weight conversion represents the carbon weight conversion in the sample. 相似文献
32.
Meta-analysis of environmental contamination by phthalates 总被引:1,自引:0,他引:1
Alexandre Bergé Mathieu Cladière Johnny Gasperi Annie Coursimault Bruno Tassin Régis Moilleron 《Environmental science and pollution research international》2013,20(11):8057-8076
Phthalate acid esters (PAE), commonly named phthalates, are toxics classified as endocrine-disrupting compounds; they are primarily used as additives to improve the flexibility in polyvinyl chloride. Many studies have reported the occurrence of phthalates in different environmental matrices; however, none of these studies has yet established a complete overview for those compounds in the water cycle within an urban environment. This review summarizes PAE concentrations for all environmental media throughout the water cycle, from atmosphere to receiving waters. Once the occurrences of compounds have been evaluated for each environmental compartment (urban wastewater, wastewater treatment plants, atmosphere, and the natural environment), we reviewed data in order to identify the fate of PAE in the environment and establish whether geographical and historical trends exist. Indeed, geographical and historical trends appear between Europe and other countries such as USA/Canada and China, however they remain location dependent. This study aimed at identifying both the correlations existing between environmental compartments and the processes influencing the fate and transport of these contaminants into the environment. In Europe, the concentrations measured in waterways today represent the background level of contamination, which provides evidence of a past diffuse pollution. In contrast, an increasing trend has actually been observed for developing countries, especially for China. 相似文献
33.
Pardo LH McNulty SG Boggs JL Duke S 《Environmental pollution (Barking, Essex : 1987)》2007,149(3):293-302
Recent studies have demonstrated that natural abundance (15)N can be a useful tool for assessing nitrogen saturation, because as nitrification and nitrate loss increase, delta(15)N of foliage and soil also increases. We measured foliar delta(15)N at 11 high-elevation spruce-fir stands along an N deposition gradient in 1987-1988 and at seven paired northern hardwood and spruce-fir stands in 1999. In 1999, foliar delta(15)N increased from -5.2 to -0.7 per thousand with increasing N deposition from Maine to NY. Foliar delta(15)N decreased between 1987-1988 and 1999, while foliar %N increased and foliar C:N decreased at most sites. Foliar delta(15)N was strongly correlated with N deposition, and was also positively correlated with net nitrification potential and negatively correlated with soil C:N ratio. Although the increase in foliar %N is consistent with a progression towards N saturation, other results of this study suggest that, in 1999, these stands were further from N saturation than in 1987-1988. 相似文献
34.
Eugenio Sanhueza Johnny Romero 《Journal of the Air & Waste Management Association (1995)》2013,63(2):157-158
An analysis of air quality data from 1970-1975 in the Los Angeles (LA) Basin has been made with emphasis on factors relevant to high hourly NO2 concentrations, (NO2). Detailed analysis of CO and SO2 air quality and the (NO x )/(CO) and (CO)/(SO2) ratios reveals that high (NO2) result mainly from vehicular sources; contributions from stationary sources to these high (NO2) of greater than 10% occur rarely. Meteorological conditions (very low early-morning inversion base height and low wind speed) favoring the formation of high (NO2) restrict the impact of elevated point NO x sources on the ground level (NO2) during the early to mid-morning hours. The overnight leftover NO x during high NO2 days is shown to originate largely from local sources near the monitoring sites. A regression analysis using NO2, NO x and HC data from downtown LA shows that a 50% reduction in (NO x ) reduces high (NO2) by 40-45%; a 50% reduction in (HC) reduces high (NO2) by 5-10%. The present analysis supports assumptions used in an earlier generalized rollback model that related NO x emissions to high 1-h average (NO2) observed at downtown LA. 相似文献