摘要 :
Diesel engines are widely used throughout the Department of Defense (DoD) for powering tactical and nontactical vehicles and vessels, off-road vehicles and equipment, engine-generator sets, aircraft ground-support equipment, and a...
展开
Diesel engines are widely used throughout the Department of Defense (DoD) for powering tactical and nontactical vehicles and vessels, off-road vehicles and equipment, engine-generator sets, aircraft ground-support equipment, and a variety of other applications. Although diesel engines are known to emit several types of pollutants into the atmosphere, human health concerns regarding the penetration of the small particulate matter (PM) into the deeper regions of the lungs have greatly increased interest in diesel PM emissions in the recent past. PM emissions are regulated as a criteria pollutant by the National Ambient Air Quality Standards established by the Clean Air Act (CAA). Although most regulations are directed at the certification of new diesel engines, increasingly, emphasis is being placed on in-service engines. The California Air Resources Board (CARB) has issued PM control regulations requiring the retrofit of school buses, garbage trucks, and offroad vehicles. To address these compliance requirements, many exhaust gas treatment devices are coming onto the market, but the selection of the optimal one (which also must meet the approval of applicable regulatory bodies) depends on several factors that must be evaluated for each application. This project demonstrated two diesel engine exhaust gas treatment devices believed to have the potential for assisting the DoD in meeting applicable PM regulatory requirements. In both cases, the technology consists of a high-temperature filter designed to remove the PM from the exhaust stream. The difference between the two filter designs involves the filter pore size and thus their ability to capture the PM emissions (50% vs. 85% PM reduction), as well as their method for regeneration. Both filters include the ability for in-use regeneration, the difference is the fact that one is regenerated passively, using only the heat of the engine, while the other is actively regenerated using direct fuel injection into the filter.
收起
摘要 :
Diesel engines are widely used throughout the Department of Defense (DoD) for powering tactical and nontactical vehicles and vessels, off-road equipment, engine-generator sets, aircraft ground-support equipment and a variety of ot...
展开
Diesel engines are widely used throughout the Department of Defense (DoD) for powering tactical and nontactical vehicles and vessels, off-road equipment, engine-generator sets, aircraft ground-support equipment and a variety of other applications. Although diesels are the most efficient of internal combustion engines and have favorable characteristics in the reduction of greenhouse gas emissions, concerns with the health effects from particulate matter (PM) and regulated hazardous air pollutants (HAP) emissions have intensified the call for cleaner burning diesels and led to recently proposed and enacted regulations increasing restrictions on diesel exhaust emissions. Because of these developments, many emissions control approaches are being pursued, including the development of cost-effective alternative fuels, such as biodiesel. Biodiesel is a nontoxic, biodegradable fuel made from organic fats and oils and serves as a replacement, substitute, and enhancer for petroleum diesel. Biodiesel may be blended with petroleum diesel in all existing diesel engines with little or no modification to the engines. It had previously been reported to reduce all regulated air pollutant emissions except emissions of nitrogen oxides (NOx). For this project, air emissions testing was performed on eight DoD-operated vehicles and two portable engines. Not all the same test cycles or fuels were used for each test engine. Multiple testing locations with different capabilities were used. The objective of this project is to establish emissions factors for DoD diesel powered engines of interest fueled with various blends and types of biodiesel, with and without the use of fuel additives that reduce NOx emissions from biodiesel. Most available biodiesel emissions data are for older heavy-duty engines tested on an engine dynamometer and fueled with a blend of virgin soybean derived biodiesel mixed with low sulfur Diesel Fuel No. 2.
收起
摘要 :
The primary objective of this study was development of an EPA approved interim particulate matter (PM) test method for non-volatile PM that can be applied at the engine exit plane of military turbine engines. New particle (volatil...
展开
The primary objective of this study was development of an EPA approved interim particulate matter (PM) test method for non-volatile PM that can be applied at the engine exit plane of military turbine engines. New particle (volatile) formation and condensation can occur in the sampling line as the sample gas temperature is lowered through interaction with the cooler sample line walls. A sampling process is defined by which non-volatile PM can be measured accurately by eliminating or accounting for the interference of new particle formation and condensation. A ground-level engine test campaign (Methodology Development Test) was conducted on an F100-220 military gas turbine engine in 2007 to experimentally investigate issues with sampling, instrument comparisons, instrument calibrations, sample line penetration and engine data representativeness. The test measurement protocol was demonstrated during the Validation Test in late 2009 using a different F100-220 engine and the diagnostics, probe-rake system, and sampling system developed for JSF applications.
收起
摘要 :
The overall objective of this work was to better elucidate the toxic and inflammatory potential of urban and rural PM from the Central Valley on a suite of pulmonary, vascular and systemic endpoints in a mouse model. Specifically...
展开
The overall objective of this work was to better elucidate the toxic and inflammatory potential of urban and rural PM from the Central Valley on a suite of pulmonary, vascular and systemic endpoints in a mouse model. Specifically, mice received one intratrachael aspiration exposure to PM2.5, and effects were evaluated at post-exposure times of 1, 2 and 4 days to explore the temporal nature of different biological responses. PM2.5 samples were collected in a rural part of Davis that is surrounded by agricultural land and an urban part of downtown Sacramento near a major freeway interchange in order to obtain a comparison between the health effects elicited by PM that has different source mixtures. Sufficient PM was collected during a single winter collection campaign to allow animal exposures and chemical analysis using the same PM sampling filter. The results demonstrate (1) that the method of extraction of PM from the filter or impactor substrate has a substantial effect on the health effects elicited and the dose-response relationship; (2) some of the endpoints, especially the pulmonary ones, responded acutely to the PM, at 1 or 2 days post administration while other endpoints, especially systemic ones, responded at longer lag times, in agreement with epidemiological studies on cardiovascular responses to PM. The results have implications for design of future research studies, and help to explain some of the inconsistencies noted in previously published research.
收起
摘要 :
Current National Ambient Air Quality Standards for particulate matter regulate the mass concentration of particles in the atmosphere. There is growing evidence that different sources of these particles have different levels of tox...
展开
Current National Ambient Air Quality Standards for particulate matter regulate the mass concentration of particles in the atmosphere. There is growing evidence that different sources of these particles have different levels of toxicity. In this work, a system was developed for collecting source oriented particles from the atmosphere suitable for toxicity testing, as described in Chapter 2 of this report. Briefly a single particle mass spectrometer identified particle sources in real time; the mass spectrometer selected a ChemVol associated with each source category to collect size-selected PM while those particles were being observed. This system was operated in Fresno, CA during the summer of 2008 and winter of 2009. The toxicity of the collected samples was assessed in a mouse model. Samples were chemically analyzed to associate them with sources prevalent in Fresno, CA. Most of the toxicity was associated with automobile and cooking sources in both seasons while in the winter toxicity was also associated with secondary compounds.
收起
摘要 :
As part of its Air Climate & Energy (ACE) research program on emerging technologies (ACE EM-3), the US EPA developed a research effort with the goals of: conducting a worldwide market survey of low cost PM sensors (<$2500), acquir...
展开
As part of its Air Climate & Energy (ACE) research program on emerging technologies (ACE EM-3), the US EPA developed a research effort with the goals of: conducting a worldwide market survey of low cost PM sensors (<$2500), acquiring such sensors, and then conducting collocated field evaluations of these sensors in direct comparison with FEM instrumentation. A total of eight such devices were obtained and sited in the established PM sensor test platform on the US EPAs RTP, NC campus (AIRS). The collocated PM2.5 FEM instrumentation with 5-minute time resolution provided the means to investigate both short duration and daily (24-hr) comparisons between the test devices and the FEM response. Potential data confounders such as temperature and relative humidity were obtained to aid in the investigation. The relationship between FEM response and the various sensors was established in a regression. Ancillary findings related to ease of use, portability, data collection efficiency, among others, were established based upon our experiences over approximately one month of continuous operation.
收起
摘要 :
On April 29 and 30, 2015, staff from the Agency for Toxic Substances and Disease Registry (ATSDR) and the United States Environmental Protection Agency (U.S. EPA) Region 4 discussed the air data available for the Bennett Landfill ...
展开
On April 29 and 30, 2015, staff from the Agency for Toxic Substances and Disease Registry (ATSDR) and the United States Environmental Protection Agency (U.S. EPA) Region 4 discussed the air data available for the Bennett Landfill fire. The U.S. EPA requested ATSDR evaluate the results of air monitoring and sampling for particulate matter to determine if community member exposures may be occurring at levels of health concern. This air monitoring and sampling data was collected by the U.S. EPA.
收起
