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1.
JoAnn S. Lighty Robert M. Britt David W. Pershing Warren D. Owens Vic A. Cundy 《Journal of the Air & Waste Management Association (1995)》2013,63(2):187-193
With landfill costs increasing and regulations on landfilling becoming more stringent, alternatives to conventional hazardous waste treatment strategies are becoming more desirable. Incineration Is presently a permanent, proven solution for the disposal of most organic contaminants, but also a costly one, especially in the case of solids which require some auxiliary fuel. The goal of this research is to develop an understanding of the phenomena associated with the evolution of contaminants from solids In the primary combustor of an Incineration system. A four-fold approach is being used. First, a bench-scale particle characterization reactor was developed to study the transport phenomena on a particle basis, where the controlling processes are mainly intraparticle. Second, a bed-characterization reactor was built to examine the controlling transport phenomena within a bed of particles, where the processes are primarily interparticle. The results of these studies can be applied to any primary combustor. A pilot-scale rotary kiln was developed to study the evolution of contaminants from solids within a realistic temperature and rotation environment. Finally, in situ measurements are being obtained from a full-scale rotary-kiln. This paper describes results obtained in a study using a commercial sorbent contaminated with toluene. The data are from the particle-characterization reactor and the rotary-kiln simulator. The results show that the method of contamination and charge size do not have a large effect on desorption, while temperature and contaminant concentration are important parameters In the evolution of contaminants in a rotary kiln. 相似文献
2.
Kelly KE Wagner DA Lighty JS Sarofim AF Bretecher B Holden B Helgeson N Sahay K Nardi Z 《Journal of the Air & Waste Management Association (1995)》2004,54(1):83-92
In-service diesel engines are a significant source of particulate matter (PM) emissions, and they have been subjected to increasingly strict emissions standards. Consequently, the wide-scale use of some type of particulate filter is expected. This study evaluated the effect of an Engelhard catalyzed soot filter (CSF) and a Rypos electrically heated soot filter on the emissions from in-service diesel engines in terms of PM mass, black carbon concentration, particle-bound polycyclic aromatic hydrocarbon concentration, and size distribution. Both filters capture PM. The CSF relies on the engine's exhaust to reach the catalyst regeneration temperature and oxidize soot, whereas the electrically heated filter contains a heating element to oxidize soot. The filters were installed on several military diesel engines. Particle concentrations and compositions were measured before and after installation of the filter and again after several months of operation. Generally, the CSF removed at least 90% of total PM, and the removal efficiency improved or remained constant after several months of operation. In contrast, the electrical filters removed 44-69% of PM mass. In addition to evaluating the soot filters, the sampling team also compared the results of several real-time particle measurement instruments to traditional filter measurements of total mass. 相似文献
3.
Charles M. Farmer Author Vitae JoAnn K. Wells Author Vitae 《Journal of Safety Research》2010,41(1):53-57
Objective
Enhanced seat belt reminders in automobiles have been shown to increase belt use rates by approximately 3 percentage points. The objective of this study was to estimate the effect of enhanced seat belt reminders on driver fatality risk.Method
Data included all passenger vehicle driver deaths and vehicle registration counts in the United States for calendar years 2000-2007. Driver fatality rates per vehicle registration per year were compared for otherwise identical vehicle models with and without enhanced seat belt reminders.Results
Driver fatality rates were 6% lower for vehicles with enhanced seat belt reminders compared with vehicles without enhanced belt reminders. After adjusting for vehicle age differences, the estimated effect of enhanced belt reminders on driver fatality risk ranged from a 9% reduction for General Motors vehicles to a 2% increase for Honda vehicles. Combining all manufacturers, enhanced belt reminders reduced fatality risk by approximately 2%. Although not statistically significant, the 2% reduction in fatality risk agrees with what should be expected from a 3 percentage point increase in seat belt use rates.Conclusions
Enhanced seat belt reminders have raised driver belt use rates and reduced fatality rates, but more aggressive systems may be needed for some drivers. It can be inferred that nonfatal injury rates also have been reduced.Impact on Industry
Manufacturers should be encouraged to put enhanced seat belt reminders on all vehicles as soon as possible. 相似文献4.
Combustion aerosols: factors governing their size and composition and implications to human health 总被引:17,自引:0,他引:17
Lighty JS Veranth JM Sarofim AF 《Journal of the Air & Waste Management Association (1995)》2000,50(9):1565-618; discussion 1619-22
Particulate matter (PM) emissions from stationary combustion sources burning coal, fuel oil, biomass, and waste, and PM from internal combustion (IC) engines burning gasoline and diesel, are a significant source of primary particles smaller than 2.5 microns (PM2.5) in urban areas. Combustion-generated particles are generally smaller than geologically produced dust and have unique chemical composition and morphology. The fundamental processes affecting formation of combustion PM and the emission characteristics of important applications are reviewed. Particles containing transition metals, ultrafine particles, and soot are emphasized because these types of particles have been studied extensively, and their emissions are controlled by the fuel composition and the oxidant-temperature-mixing history from the flame to the stack. There is a need for better integration of the combustion, air pollution control, atmospheric chemistry, and inhalation health research communities. Epidemiology has demonstrated that susceptible individuals are being harmed by ambient PM. Particle surface area, number of ultrafine particles, bioavailable transition metals, polycyclic aromatic hydrocarbons (PAH), and other particle-bound organic compounds are suspected to be more important than particle mass in determining the effects of air pollution. Time- and size-resolved PM measurements are needed for testing mechanistic toxicological hypotheses, for characterizing the relationship between combustion operating conditions and transient emissions, and for source apportionment studies to develop air quality plans. Citations are provided to more specialized reviews, and the concluding comments make suggestions for further research. 相似文献
5.
Jeon SJ Meuzelaar HL Sheya SA Lighty JS Jarman WM Kasteler C Sarofim AF Simoneit BR 《Journal of the Air & Waste Management Association (1995)》2001,51(5):766-784
For a recent exploratory study of particulate matter (PM) compositions, origins, and impacts in the El Paso/Juarez (Paso del Norte) airshed, the authors relied on solvent extraction (SX)-gas chromatography/mass spectrometry (GC/MS) procedures to characterize 24-hr quartz fiber (QF) filter samples obtained from nine spatially distributed high-volume (Hi-Vol) PM10 samplers as well as on thermal desorption (TD)-GC/MS methods to characterize 45 time-resolved (2-hr) filter samples obtained with modified 1-m3/hr PM10 samplers. Principal component analysis and related chemometric techniques were used for data reduction and data fusion as well as for multiway data correlation. A high degree of correspondence (R2 = 0.821) was found between the rapid TD-GC/MS method (which can be carried out on 2-hr filter slices containing only microgram amounts of sample) and conventional SX-GC/MS procedures. The four main source patterns of organic PM components observed in GC/MS profiles of both temporally and spatially resolved receptor samples obtained in the El Paso/Juarez border airshed during the study period are interpreted to represent (1) vehicular emissions plus resuspended urban dust; (2) biomass combustion; (3) native vegetation detritus and resuspended agricultural dust; and (4) waste burning. Moreover, principal component analysis of combined, variance-weighted, temporally resolved TD-GC/MS data and spatially resolved SX-GC/MS data was used to determine approximate source locations for specific PM components identified in time-resolved receptor sample profiles. The same approach can be used to determine approximate circadian concentration profiles of specific PM components identified in spatially resolved receptor sample profiles. 相似文献
6.
Danz NP Niemi GJ Regal RR Hollenhorst T Johnson LB Hanowski JM Axler RP Ciborowski JJ Hrabik T Brady VJ Kelly JR Morrice JA Brazner JC Howe RW Johnston CA Host GE 《Environmental management》2007,39(5):631-647
Integrated, quantitative expressions of anthropogenic stress over large geographic regions can be valuable tools in environmental research and management. Despite the fundamental appeal of a regional approach, development of regional stress measures remains one of the most important current challenges in environmental science. Using publicly available, pre-existing spatial datasets, we developed a geographic information system database of 86 variables related to five classes of anthropogenic stress in the U.S. Great Lakes basin: agriculture, atmospheric deposition, human population, land cover, and point source pollution. The original variables were quantified by a variety of data types over a broad range of spatial and classification resolutions. We summarized the original data for 762 watershed-based units that comprise the U.S. portion of the basin and then used principal components analysis to develop overall stress measures within each stress category. We developed a cumulative stress index by combining the first principal component from each of the five stress categories. Maps of the stress measures illustrate strong spatial patterns across the basin, with the greatest amount of stress occurring on the western shore of Lake Michigan, southwest Lake Erie, and southeastern Lake Ontario. We found strong relationships between the stress measures and characteristics of bird communities, fish communities, and water chemistry measurements from the coastal region. The stress measures are taken to represent the major threats to coastal ecosystems in the U.S. Great Lakes. Such regional-scale efforts are critical for understanding relationships between human disturbance and ecosystem response, and can be used to guide environmental decision-making at both regional and local scales. 相似文献
7.
Donald Reinfurt Allan Williams JoAnn Wells Eric Rodgman 《Journal of Safety Research》1996,27(4):209-215
A study was undertaken in North Carolina to determine the characteristics of the minority of drivers who were not using seat belts following an extensive publicity/enforcement campaign, which had increased statewide use to 80%. Vehicles and drivers whose seat belt use was observed at sites across North Carolina were matched against Division of Motor Vehicles registration and driver history files for vehicle owners. The study file consisted of those observed drivers who matched the owners with respect to sex, race, and approximate age. The results of this investigation indicate that nonuse of seat belts was associated with males; younger age (<35); older vehicles (pre-1985); vehicles other than cars, especially pickups; and poor driving records. Telephone survey information indicated that nonusers were less likely to have health care coverage, more likely to acknowledge having consumed large amounts of alcohol in the past year, and more likely to have an arrest record. When asked about enforcement of the belt use law, many nonusers said that they would not respond to higher fines but they would respond to driver license points. To change the belt use behavior of this hard-core nonuser population, it well may be necessary as was done in Canada to combine publicity/enforcement campaigns with driver license points as a penalty for nonuse. 相似文献
8.
JoAnn M. Hanowski Peter T. Walter Gerald J. Niemi 《Journal of the American Water Resources Association》2002,38(3):633-639
ABSTRACT: Forest buffers adjacent to water bodies are widely prescribed in forest management to protect ecological functions of riparian systems. To date, buffers have been applied on the landscape uniformly without quantifying their effectiveness or the effects they have on landscape characteristics. Our objective was to quantify landscape characteristics (amount of edge and interior forest) when buffers were applied to water bodies in a 100 by 100 km area of northern Minnesota. We used a Landsat classified image in a geographic information system platform to apply two buffer widths ?28.5 m and 57 m — to water bodies, including nonforested wetlands, intermittent or perennial streams, and lakes. A total of 107,141 ha (18.3 percent) of the forest area was adjacent to and within 28.5 m of these water bodies, while 201,457 ha of forest was within 57 m, representing 34.4 percent of the total forest area. Imposing a 28.5 m buffer on water bodies increased the amount of edge and interior forest in the study area. When water bodies were buffered with a 57 m forest strip, we found a slight increase in forest edge from the current condition, and this buffer width resulted in the largest amount of interior forest. Interior forest increased with the 57 m buffer due to the density of water bodies in this region; adjacent water bodies coalesced when buffers were applied and formed isolated forest islands that contained forest interior habitat. Instead of wholesale application of set width riparian buffers, we suggest that ecological conditions of riparian areas be evaluated on a site level and that areas that currently provide important riparian conditions be maintained on the landscape with appropriate management practices. 相似文献
9.
Rogers F Arnott P Zielinska B Sagebiel J Kelly KE Wagner D Lighty JS Sarofim AF 《Journal of the Air & Waste Management Association (1995)》2005,55(5):583-593
Particulate-phase exhaust properties from two different types of ground-based jet aircraft engines--high-thrust and turboshaft--were studied with real-time instruments on a portable pallet and additional time-integrated sampling devices. The real-time instruments successfully characterized rapidly changing particulate mass, light absorption, and polycyclic aromatic hydrocarbon (PAH) content. The integrated measurements included particulate-size distributions, PAH, and carbon concentrations for an entire test run (i.e., "run-integrated" measurements). In all cases, the particle-size distributions showed single modes peaking at 20-40nm diameter. Measurements of exhaust from high-thrust F404 engines showed relatively low-light absorption compared with exhaust from a turboshaft engine. Particulate-phase PAH measurements generally varied in phase with both net particulate mass and with light-absorbing particulate concentrations. Unexplained response behavior sometimes occurred with the real-time PAH analyzer, although on average the real-time and integrated PAH methods agreed within the same order of magnitude found in earlier investigations. 相似文献
10.
Jiang P Lignell DO Kelly KE Lighty JS Sarofim AF Montgomery CJ 《Journal of the Air & Waste Management Association (1995)》2005,55(4):437-445
Over the past several years, numerous studies have linked ambient concentrations of particulate matter (PM) to adverse health effects, and more recent studies have identified PM size and surface area as important factors in determining the health effects of PM. This study contributes to a better understanding of the evolution of particle size distributions in exhaust plumes with unconfined dilution by ambient air. It combines computational fluid dynamics (CFD) with an aerosol dynamics model to examine the effects of different streamlines in an exhaust plume, ambient particle size distributions, and vehicle and wind speed on the particle size distribution in an exhaust plume. CFD was used to calculate the flow field and gas mixing for unconfined dilution of a vehicle exhaust plume, and the calculated dilution ratios were then used as input to the aerosol dynamics simulation. The results of the study show that vehicle speed affected the particle size distribution of an exhaust plume because increasing vehicle speed caused more rapid dilution and inhibited coagulation. Ambient particle size distributions had an effect on the smaller sized particles (approximately 10 nm range under some conditions) and larger sized particles (>2 microm) of the particle size distribution. The ambient air particle size distribution affects the larger sizes of the exhaust plume because vehicle exhaust typically contains few particles larger than 2 microm. Finally, the location of a streamline in the exhaust plume had little effect on the particle size distribution; the particle size distribution along any streamline at a distance x differed by less than 5% from the particle size distributions along any other streamline at distance x. 相似文献