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841.
J.I. Accortt A. L Plumley J.R. Martin 《Journal of the Air & Waste Management Association (1995)》2013,63(10):966-969
This paper includes results from pilot plant studies and early field demonstration units and a discussion of the application of the limestone wet scrubbing process to a low sulfur syb-butuminous coal. This latter application required the development of a hybrid two stage scrubber to enable collection of the fine particulate matter as well as removal of a significant amount of the sulfur dioxide. 相似文献
842.
R.E. George J.S. Nevitt J.A. Verssen 《Journal of the Air & Waste Management Association (1995)》2013,63(7):507-515
This paper is directed to those concerned with the air environment and its degradation by the burden of pollution from jet aircraft operations. A summary is presented of the results of a comprehensive air pollution study of jet aircraft operations at the Los Angeles International Airport (LAX). Included in the data obtained from this study are jet engine exhaust measurements for currently used turboprop, turbojet and turbofan engines; measurements of specific contaminants in the atmosphere inside and outside of passenger terminals and ticketing areas, and in aircraft cabins during ground operations including passenger loading and taxiing prior to takeoff; also presented are ambient air measurements in a two-mile radius of the airport. An evaluation is made of the emissions of contaminants from air transport operations and all related ground activities including motor vehicles, that contribute to the total atmospheric contaminant burden at the airport. 相似文献
843.
S. F. Liang C. V. Sternling T. R. Galloway 《Journal of the Air & Waste Management Association (1995)》2013,63(7):605-607
This paper presents a simplified analysis to determine the variables that affect the empirical correlation factor used in the lead peroxide method. The rate of sulfation has been determined from two different models. In the first model, the mass transfer rate is calculated from the gas phase resistance alone whereas in the second model, the diffusion resistance in the gel phase is assumed to be the rate limiting step. Although the gas phase and the gel phase resistances may be both important in the actual case, it has been found that the correlation factor based on the first model is adequate to describe general experimental observations. Reasonable agreement has been obtained between the measured and the calculated va|ue of the correlation factor. 相似文献
844.
B. R. Hubble Stanley Siegel L. H. Fuchs H. R. Hoekstra B. Tani P. T. Cunningham 《Journal of the Air & Waste Management Association (1995)》2013,63(4):343-346
Abstract Inspection and maintenance programs for motor vehicles in the United States increasingly use loaded mode mass emissions testing (IM240). A method was developed to predict mass emission rates and mass emission changes, particularly from repair benefits, using a low-cost, portable four-gas non-dispersive infrared (NDIR) vehicle exhaust gas analyzer. A single vehicle was tested several times with the analyzer while on the dynamometer and undergoing successive repairs. Excellent correlations for CO and HC were observed. Five vehicles were measured using an on-road driving loop before and after emissions-related repairs, while another three vehicles were tested with no repairs performed. The on-road concentration data used to guide the repair process were converted to grams per gallon; when divided by estimated miles per gallon, this gave grams per mile emissions for comparison to IM240. Correlation coefficients (r2) of 0.87 for CO and 0.76 for HC were achieved for the 13 tests. The linear correlations between IM240 and emissions measured by this method would allow repair facilities to perform a relatively inexpensive test for diagnostic purposes and to estimate repair effectiveness without the need for a dynamometer. 相似文献
845.
Wayne R. Ott 《Journal of the Air & Waste Management Association (1995)》2013,63(6):543-547
A critical problem arises if one attempts to compare data from air monitoring stations in different cities, because there are so many differences in monitoring site locations. Some air monitoring stations are on the 6 th and 8 th floors of tall buildings in downtown areas; some are at ground level beside streets with heavy traffic; some are in residential areas with little traffic or industry; and some are in suburban or nonurban areas. Unfortunately, there is ample evidence that the location of a monitoring station relative to nearby sources (such as highways) affects the values observed at the station, particularly for carbon monoxide and other vehicular pollutants. Thus, a standardized system of site selection, such as the one proposed here, appears essential to improve the comparability and meaningfulness of data obtained from different air monitoring stations throughout the Nation. 相似文献
846.
D.P. Hoult S.R. O'Dea G.L. Touchton R.J. Ketterer 《Journal of the Air & Waste Management Association (1995)》2013,63(1):56-60
Plume rise downwind of a large stationary gas turbine was measured in the field and the conditions were then scaled in the laboratory. For the laboratory, the plume exit conditions, wind velocity and temperature profiles, and wind direction were matched. It was found that for high temperature exhaust, the buoyancy is best matched by calculating a dimensionless density difference. With properly calculated buoyancy length scales, the plume trajectories were compared and were found to agree quite well. The probability distributions of the entrainment constant and the average values of the entrapment constant with downwind distance were compared. The field data showed about 15% greater plume rise. The median entrainment constant was about 10% greater for the lab test and the shape of the probability distribution matched very closely. 相似文献
847.
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
848.
R. D. Steele G. C. Page G. F. Meenaghan 《Journal of the Air & Waste Management Association (1995)》2013,63(6):634-635
Reference methods for the determination of mercury emissions from stationary sources typically include collection of mercury by solutions which are acidic and oxidizing. In the presence of high levels of SO2 the oxidizing capacity of these absorbing solutions will be degraded and the collection efficiency for mercury compromised. This seriously limits the usefulness of the reference methods as they apply to the mining and smelting industries. In the present work peroxide is used to remove SO2 and acidic permanganate is used to collect mercury. At a mean sampling rate of 10 L/min concentrations of at least 12 mg/m3 mercury can be satisfactorily collected in the presence of up to 20,000 ppm SO2. 相似文献
849.
Timothy M. Gilmore Thomas R. Hanna 《Journal of the Air & Waste Management Association (1995)》2013,63(10):965-967
Recent investigations have indicated that ambient air CO measurements may not reflect population exposure to CO. The lack of correlation may be due to improper siting of CO instruments, improper interpretation of air quality data, or both. Studies of population carboxy-hemoglobin levels are evaluated and compared with ambient air data., No significant correlation was found between median population COHb levels and reductions in CO concentrations required to meet ambient air standards when calculations used to estimate reductions were based on the second highest 8 hour average. However, calculated reductions based on annual average concentrations and a trend analysis technique correlated significantly with COHb levels in five cities from which both CAMP and COHb data were available. Studies to determine the nature of the relationship between ambient air CO concentrations and population COHb levels are needed. The differences between the Occupational Safety and Health Act Regulations and the National Ambient Air Standards for carbon monoxide should be scrutinized to determine if a redefinition of the standards or their applicability is warranted. A reevaluation of the controls necessary to make reductions in population COHb burden may be necessary. 相似文献
850.
Howard Moore Kathryn R. Williams 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1043-1045
The techniques of Principal Component Analysis (PCA) and subsequent regression analysis were used in an attempt to describe local and upwind chemical and physical factors which affect the variability of SO4 –2 concentrations observed in a rural area of the northeastern U.S. The data used in the analyses included upwind and local O3 concentrations, temperature, relative humidity and other climatological information, SO2, and meteorological information associated with backward trajectories. The investigation identified five principal components, three major (eigenvalues >1) and two minor (eigenvalues < one), which accounted for 52% (r = 0.72) of the variability in the SO4 –2 regression model. These components can be described as representing local and upwind photochemistry, droplet growth, SO2 emissions, and air mass characteristics. The study also indicated that in future studies it will be necessary to a priori select air pollution and meteorological variables for measurement to potentially increase the sensitivity of this type of receptor model. 相似文献