Main Title |
Residence Time of Contaminants Released in Surface Coal Mines: A Wind-Tunnel Study. |
Author |
Thompson, R. S. ;
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CORP Author |
Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Research and Exposure Assessment Lab. |
Publisher |
Aug 93 |
Year Published |
1993 |
Report Number |
EPA/600/A-93/229; |
Stock Number |
PB93-236586 |
Additional Subjects |
Coal mines ;
Atmospheric diffusion ;
Dust ;
Emission factors ;
Air pollution ;
Surface mining ;
Wind direction ;
Environmental transport ;
Wind tunnels ;
Mathematical models ;
Residence time
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Internet Access |
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Holdings |
Library |
Call Number |
Additional Info |
Location |
Last Modified |
Checkout Status |
NTIS |
PB93-236586 |
Some EPA libraries have a fiche copy filed under the call number shown. |
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07/26/2022 |
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Collation |
23p |
Abstract |
The 1990 Clean Air Act Amendments direct the U.S. Environmental Protection Agency to evaluate and modify, as required, existing dispersion models for the prediction of dispersion of dust from surface coal mines. The application of mathematical air pollution dispersion models to the dispersion of dust from surface coal mines requires knowledge of not only the amount of dust generated in the mine, but the fraction of that generated that actually escapes from the mine. The escape fraction can be related to the residence time that released material will remain, on average, within the mine. The concentration in the mine was found to follow an exponential decay function from which an exponential decay time constant (or residence time) was computed for each case. A semi-empirical formula was found that related the residence time to the mine geometry and wind direction quite well. This formula can be used to estimate escape fraction in determining the source strength for the application of mathematical dispersion models. |
Supplementary Notes |
Presented at the American Meteorlogy Society's Joint Conference on the Applications of Air Pollution Meteorology with the Air and Waste Management Association (8th), Nashville, TN., January 23-28, 1994. See also PB85-185411. |
Category Codes |
68A; 48A |
NTIS Prices |
PC A03/MF A01 |
Primary Description |
600/09 |
Document Type |
NT |
Cataloging Source |
NTIS/MT |
Control Number |
330925977 |
Origin |
NTIS |
Type |
CAT |