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991.
S. A. Batterman J. A. Fay D. Golomb 《Journal of the Air & Waste Management Association (1995)》2013,63(11):1286-1291
Based on data collected in St. Louis, Philadelphia and other eastern U.S. cities, we conclude that a significant fraction of the PM-10 concentration is "background." In these urban areas the background fraction ranges from 35 to 80 percent of the daily, monthly or annual concentration. The bulk of the background appears to be of regional origin. The average chemical makeup of eastern U.S. PM-10 is sulfate as SO4, 21-34 percent; crustal material, 14-39 percent; "unknown" (carbonaceous matter, ammonium, nitrate and water), 36-51 percent, all of which is difficult to apportion to specific sources. Dispersion modeling using a local source inventory can account only for a small portion of the total PM-10 mass. Emission roll-back of local sources may have a limited effect on reducing total concentrations of PM-10. 相似文献
992.
J. A. Sousa J. E. Houck J. A. Cooper J. M. Daisey 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1439-1444
The Deep Creek Lake Study of 1983 provided an opportunity to obtain emission samples from coal-fired power plants with a dilution sampler for mutagenicity testing. Stack and ambient samples of particulate matter were collected with a dilution sampler at three coal-fired power plants in West Virginia. Samples were sequentially extracted with cyclohexane (CX), dichloromethane (DCM) and acetone (ACE) and tested for mutagenicity in the Ames Salmonella/microsome assay using TA98 (-S9). For the stack samples, the CX, DCM and ACE fractions constituted 1.0, 0.7 and 98.1 percent of the total extractable organic material (EOM), respectively, compared to 28.5, 7.4 and 64.1 percent for the ambient samples. In contrast, the mutagenic activity of the organic fractions was concentrated in the CX and DCM fractions. The cyclohexane- and dichloromethane-soluble fractions of the stack samples from all locations exhibited mutagenicity when tested in the plate incorporation assay. No significant response was observed with the acetone fraction. When tested with Kado's modification of the preincubation assay, the acetone-soluble fraction did exhibit mutagenic activity comparable to that of the other fractions when expressed in units of revertants per milligram of particular matter. Chemical analyses of one of the acetone-soluble fractions indicated that half of the mass was sulfuric acid while the remainder consisted of C, H and O. More than 30 peaks were detected in the high pressure liquid chromatogram of this fraction. Although little mutagenic activity was detected in the polar ACE fraction of the diluted stack emissions samples with this single bioassay, in view of the large mass of this fraction, further investigation of the chemical composition and genotoxic activity of this fraction would be prudent. 相似文献
993.
D.A. Froelich G.M. Graves 《Journal of the Air & Waste Management Association (1995)》2013,63(3):314-321
The Clean Air Act Amendments of the early 1970s required coal burning utilities to reduce their emissions of sulfur dioxide. Lime or limestone based wet systems were employed for flue gas desulfurization (FGD). These systems reduced flue gas temperatures to below acid dew point conditions. Concerned about the prospect of ductwork exposed to a saturated, acid-rich environment, most utilities turned to stack gas reheat (SGR) to increase flue gas temperatures. By 1980, 82 percent of all FGD facilities employed SGR. Today there are about 130 FGD systems of which 101 employ some form of stack gas reheat. 相似文献
994.
Experimental Characterization of Atmospheric Diffusion in Complex Terrain with Land-Sea Interactions
M. M. Mill´n E. Otamendi L. A. Alonso I. Ureta 《Journal of the Air & Waste Management Association (1995)》2013,63(7):807-811
The body of information presented in this paper is directed to scientists working in atmospheric dispersion research and model development. Two years of field measurements in the coastal area of Bilbao in northern Spain show that the diffusion behavior in this complex terrain can be classified into several well defined patterns, which correspond to certain meteorological conditions. The approach taken has been the systematic use of SO2 remote sensors (COSPEC) and ground level monitors in moving platforms which are used to follow and document the flow of the air mass. Results to date show that complex reentry cycles can occur and that synoptically different flows may be indistinguishable by wind sensors at ground level (affected by channeling), and yet result in totally different observed pollution levels by a fixed monitoring network (affected by topographical effects). These results are being used to parameterize the cause-effect relationships and guide the modeling efforts in this area of complex terrain. 相似文献
995.
A. G. Blasewitz B. F. Judson 《Journal of the Air & Waste Management Association (1995)》2013,63(4):223-229
Abstract An ozone (O3) exposure assessment study was conducted in Toronto, Ontario, Canada during the winter and summer of 1992. A new passive O3 sampler developed by Harvard was used to measure indoor, outdoor, and personal O3 concentrations. Measurements were taken weekly and daily during the winter and summer, respectively. Indoor samples were collected at a total of 50 homes and workplaces of study participants. Outdoor O3 concentrations were measured both at home sites using the passive sampler and at 20 ambient monitoring sites with continuous monitors. Personal O3 measurements were collected from 123 participants, who also completed detailed time-activity diaries. A total of 2,274 O3 samples were collected. In addition, weekly air exchange rates of homes were measured. This study demonstrates the performance of our O3 sampler for exposure assessment. The data obtained are further used to examine the relationships between personal, indoor (home and workplace), and outdoor O3 concentrations, and to investigate outdoor and indoor spatial variations in O3 concentrations. Based on home outdoor and indoor, workplace, and ambient O3 concentrations measured at the Ontario Ministry of the Environment (MOE) sites, the traditional microenvironmental model predicts 72% of the variability in measured personal exposures. An alternative personal O3 exposure model based on outdoor measurements and time-activity information is able to predict the mean personal exposures in a large population, with the highest R2 value of 0.41. 相似文献
996.
Judith C. Chow John G. Watson Richard T. Egami Clifton A. Frazier Zhiqiang Lu Andrew Goodrich 《Journal of the Air & Waste Management Association (1995)》2013,63(8):1134-1142
Street sweeping is often proposed as a means of reducing the emissions from paved roads. The objective of this study was to evaluate the effectiveness of street sweeping on ambient particulate matter concentrations and to determine the difference In source contributions to PM10 concentrations between street sweeping and non-street sweeping periods. Chemically-speciated measurements of PM10 and PM2.5 were taken in the commercial section of Reno, Nevada, for a one-month sampling period. The Chemical Mass Balance (CMB) model was applied to these data and an average of approximately 50 percent of the PM10 was apportioned to resuspended geological material. During half of the sampling period, streets In the vicinity of the sampling site were completely swept with a regenerative-air vacuum sweeper, while no sweeping was performed during the remainder of the experiment. Ratios of primary geological contributions divided by primary motor vehicle contributions to PM10 were compared between sweeping and non-sweeping periods using analysis of variance. This ratio of source contributions minimizes the effects of variations in traffic volume and meteorological dispersion. No significant differences in geological contributions to PM10 were detected as a result of regenerative-air vacuum street sweeping. 相似文献
997.
Quanlu Wang Mark A. DeLuchi Daniel Sperling 《Journal of the Air & Waste Management Association (1995)》2013,63(9):1275-1284
Alternative vehicular fuels are proposed as a strategy to reduce urban air pollution. In this paper, we analyze the emission Impacts of electric vehicles In California for two target years, 1995 and 2010. We consider a range of assumptions regarding electricity consumption of electric vehicles, emission control technologies for power plants, and the mix of primary energy sources for electricity generation. We find that, relative to continued use of gasoline-powered vehicles, the use of electric vehicles would dramatically and unequivocally reduce carbon monoxide and hydrocarbons. Under most conditions, nitrogen oxide emissions would decrease moderately. Sulfur oxide and particulate emissions would Increase or slightly decrease. Because other areas of the United States tend to use more coal in electricity generation and have less stringent emission controls on power plants, electric vehicles may have less emission reduction benefits outside California. 相似文献
998.
999.
Vic A. Cundy Thomas W. Lester Arthur M. Sterling Alfred N. Montestruc John S. Morse Christopher B. Leger 《Journal of the Air & Waste Management Association (1995)》2013,63(7):944-952
Temperature and stable species concentration data are presented from various locations within a full-scale rotary kiln incinerator firing natural gas/carbon tetrachloride/air. The data are being collected as part of a cooperative program involving university, industry and government participation. The overall goal of the program is to develop a more sophisticated understanding of and a predictive capability for rotary kiln and afterburner performance as influenced by basic design and operational parameters. Non-uniformities in stable species and temperature exist for this particular kiln, at the kiln exit, under certain operating conditions. Flow perturbations from within the kiln were found to persist into the afterburner, but not into the stack. High destruction and removal efficiencies (DRE’s) were achieved under the operating conditions of these tests through adequate secondary combustion processing. 相似文献
1000.
Vic A. Cundy Thomas W. Lester Arthur M. Sterling Alfred N. Montestruc John S. Morse Christopher B. Leger 《Journal of the Air & Waste Management Association (1995)》2013,63(8):1073-1085
Detailed temperature and stable species concentration data are presented from the kiln exit, transition section and afterburner of a full-scale incinerator facility firing natural gas/carbon tetrachloride/air. The data are collected as part of a cooperative program involving university, industry and government participation. The overall goal of the program is to develop an understanding and predictive capability for rotary kiln and afterburner performance as influenced by basic design and operational parameters. The data demonstrate that nonuniformities in stable species and temperature exist, under certain operating conditions, at the kiln exit in the vertical direction only. Measurements from the transition section indicate that non-uniformities may exist within this region under certain operating conditions. Flow perturbations from within the kiln can persist into the afterburner, although the degree of nonuniformity is substantially reduced compared to either the kiln or transition sections. High destruction and removal efficiencies were achieved under all operating conditions of these tests through a combination of kiln and secondary combustion processing. 相似文献