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941.
Robert A. O'Dell Mansoor Taheri Robert L. Kabel 《Journal of the Air & Waste Management Association (1995)》2013,63(11):1104-1109
A mass transfer approach is used in developing a practical mathematical model of gaseous pollutant uptake by leaves in which a series of resistances is summed across a concentration difference. The body of information presented in this paper is directed to plant pathologists or physiologists in the field of vegetal-pollutant effects and to people interested in the natural removal of air pollutants by vegetation. Correlations are given to calculate the aerodynamic and the stomatal resistances to uptake, while both a qualitative investigation and quantitative estimates are made of the mesophyllic resistance. The factors which control the aerodynamic resistance, ra, are leaf size and wind speed, while the leaf physiology is the determinant of the stomatal resistance, rs . It is noted that the chemical reaction rate and pollutant diffusivity in the mesophyll control the mesophyllic resistance, rm, though the overall gas phase mesophyllic resistance, Hrm, is strongly a function of pollutant solubility in water. Finally, the overall model is compared to earlier experimental work on vegetal uptake of SO2. 相似文献
942.
R. A. Stoehr J. P. Pezze 《Journal of the Air & Waste Management Association (1995)》2013,63(11):1119-1122
The evolution of H2S and SO2 from hot blast furnace slags by reaction with H2O has been found to be dependent upon the presence of O2 or H2 in the reaction zone as well as on the temperature. H2 has been found to produce a small increase in H2S and a small decrease in SO2 emission, while O2 has been found to produce a very great inhibiting effect on H2S emission and only a small increase in SO2 emission. The total emission of sulfur bearing gases is much less when H2O + air is blown at the slag than when H2O + Ar is blown at the slag, particularly at 1200°C and above. These effects may be useful in attempts to design systems for slag quenching which will produce less pollution. 相似文献
943.
D. V. Sandberg S. G. Pickford E. F. Darley 《Journal of the Air & Waste Management Association (1995)》2013,63(3):278-281
Pollutants sampled during the burning of 30 lb ponderosa pine fuel beds yielded emission factors for CO, hydrocarbon gases, and par-ticulate matter of 146, 8.4, and 9.1 lb/ton of fuel, respectively. When similar beds were treated with diammonium phosphate flame retardant, these factors increased to 166, 11.7, and 19.3 lb/ton of fuel, respectively. Gas chromatographic analysis of hydrocarbon gases showed that 15-40% of this material was composed of methane and eth-ylene. Ethane and acetylene were the next most abundant materials, with photochemically important materials constituting minor portions of this gaseous component. Fuel beds treated with flame retardant produced more oiefins, and this production lasted throughout the smoldering phase of burning. These tests showed that the smoldering phase of combustion is of major importance to air pollutant production during slash burning. The initial 80% of the fuel burned accounted for only 20-30% of HC and CO emissions. This suggests that a rapid mop-up of slash burns could substantially reduce air pollutant production. 相似文献
944.
Laurel J. Staley Marta K. Richards George L. Huffman Robert A. Olexsey Barry Dellinger 《Journal of the Air & Waste Management Association (1995)》2013,63(3):321-331
Measurements conducted on full-scale hazardous waste incinerators have occasionally shown a relationship between carbon monoxide (CO) emissions and emissions of toxic organic compounds. In this study, four mixtures of chlorinated C1 and C2 hydrocarbons were diluted in commercial-grade heptane and burned in a water-cooled turbulent flame reactor (TFR) under two different excess air levels. No correlation between CO and organic emissions could be discerned. Reasons for this lack of observable correlations are discussed in terms of combustion and chemical reaction kinetic theory. 相似文献
945.
M. E. Smith T. T. Frankenberg 《Journal of the Air & Waste Management Association (1995)》2013,63(6):595-601
A study of the “before” and “after” ground-level S02 concentrations near the Muskingum River Plant of the American Electric Power System shows that the conversion from low to high stacks has accomplished marked reductions in ambient concentrations. These reductions are in reasonable agreement with theoretical calculations and are most apparent within 5 km of the source. EPA Standards are now being met in this area despite the presence of the 1440 MW power plant burning 5% sulfur fuel with no treatment of the stack gas. 相似文献
946.
Terry A. Ferrar Alan B. Brownstein 《Journal of the Air & Waste Management Association (1995)》2013,63(6):602-604
Confronted with shortages of low sulfur content residual fuel oil and, consequently, faced with the threat of social and economic upheaval, several air pollution control authorities in the Northeastern states were forced to relax hard-won air quality standards during the winter of 1972. The authorities did so by granting variances to their sulfur content standards for residual fuel oil. This paper examines the institutional characteristics of these variance policies from an economic incentive standpoint. After setting up desirable structural criteria for institutional design of such crisis policies, the authors examine the experience of the winter of 1972 and arrive at policy guidelines which recommend themselves for consideration in future periods of fuel oil shortages. 相似文献
947.
Roger J. Cheng Volker A. Mohnen Thomas T. Shen Michael Current John B. Hudson 《Journal of the Air & Waste Management Association (1995)》2013,63(8):787-790
The emphasis on participate control from industrial processes has been shifted recently towards fine particulates, having diameters less than 3 microns. There exists an urgent need for more scientific information of fine particle characterization.1,2 Coal and oil fired power plants are among the largest anthropogenic point sources of particulate matter.3 Limited knowledge is available on particle size distribution and trace metal composition in power plant emissions.4-7 The morphological properties of particle emissions have been largely neglected. In this report we present some information on particle characteristics for an oil-fired and coal-fired power plant. 相似文献
948.
E. E. A. Rouillard R.E. Hicks 《Journal of the Air & Waste Management Association (1995)》2013,63(6):599-601
In isokinetic sampling from a gas stream it is usually assumed that the flow pattern upstream of the sampling probe is not affected by the presence of the probe. That some probes do seriously affect the gas streamlines is shown by velocity traverses taken with a hot wire anemometer under controlled flow conditions in a wind tunnel. The degree to v/hich the streamlines are affected depends on the wall thickness and taper of the nozzle, the stem diameter, as well as on the size and proximity of sampling accessories in the vicinity of the nozzle. For a probe to cause negligible disturbance under isokinetic conditions it should have a sharp-edged nozzle with little or no outside bevel, and the stem of the probe should be at least 11 stem diameters downstream from the nozzle inlet. 相似文献
949.
950.