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NARSTO Workshop on Innovative Methods for Emission Inventory Development and Evaluation University of Texas, Austin October 14-17, 2003 |
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Emission Inventory Development through Highly-time-resolved Ambient Sampling
John M. Ondov
Department of Chemistry and Biochemistry
University of Maryland, College Park, MD 20742
Noreen Poor
Environmental and Occupational Health, College of Public Health
University of South Florida, Tampa, FL 33612
Highly-time resolved metals measurements have been made at five urban locations and near a coke oven using the University of Maryland Semicontinuous Elements in Aerosol Sampler. In each case, aerosol slurry samples were collected at 30-minute intervals, i.e., at periods short relative to changes in wind direction, and analyzed off-line by mutli-element graphite furnace Atomic Absorption Spectroscopy for up to 12 elements useful as markers of primary particle emissions of high-temperature combustion sources. At this resolution, the plumes of individual sources, including the coke oven, coal-fired power plants, a copper smelter, and a battery recycling plant, have been readily observed as excursions in time series profiles of the concentrations of the various marker elements. Over the scale of 20 to 40 km, wind and source angles are nearly identical when the former are relatively constant during the time required for plume transport. In College Park, MD, the temporal pattern in the airborne Se concentrations correlated well with that of the generating load of a coal-fired power plant 16-km to the southwest. When combined with ambient measurements of SO , a pollutant whose emission rate is measured with a continuous monitor, it should be possible to estimate emission rates of primary particles and their constituents. For at least some sources, high-frequency ambient measurements could obviate the need for in-stack measurements for development of emission inventories. Ambient ground-level measurements made in the vicinity of the above mentioned sources will be presented along with some preliminary estimates of emission rates from a coal-fired power plant.