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COMPARISON OF MONODISPERSE AND POLYDISPERSE AEROSOL DEPOSITION IN A PACKED BED
Citation:
Kim, C. S. AND J. A. Rosati. COMPARISON OF MONODISPERSE AND POLYDISPERSE AEROSOL DEPOSITION IN A PACKED BED. Presented at American Association for Aerosol Research (AAAR), Charlotte, NC, October 7-11, 2002.
Description:
COMPARISON OF MONODISPERSE AND POLYDISPERSE AEROSOL DEPOSITION IN A PACKED BED. Jacky A. Rosati, Dept. of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC 27599; Chong S. Kim, USEPA National Health and Environmental Effects Research Laboratory, RTP, NC 27711.
Currently, a series of monodisperse aerosols are used to simulate a polydisperse aerosol in inhaled particle deposition studies. Our work compares the deposition of monodisperse and polydisperse di-2(ethylhexyl) sebacate aerosols in a packed bed. The packed bed is used as an approximate surrogate to the human lung. Nebulizers are used to generate polydisperse aerosols with mass median aerodynamic diameters (MMADs) from 0.3 to 3 m, and geometric standard deviations (GSDs) of 1.8 - 2.0. A Monodisperse Aerosol Generator (MAGE) is used to generate monodisperse aerosols with MMADs from 0.3 to 5.0 m, and GSDs of 1.1. Aerosol is "inhaled" and "exhaled" using a Harvard respirator pump. Complete size distributions of inhaled and exhaled aerosol are measured by an Aerodynamic Particle Sizer (APS) and a Scanning Mobility Particle Sizer (SMPS).
Deposition of an aerosol is determined by comparing discrete size fractions of inhaled and exhaled aerosol. Total deposition of the aerosol is then determined from the sum of the deposition of discrete size fractions. To evaluate whether the use of a polydisperse aerosol differs from the use of a monodisperse aerosol series, discrete sections of polydisperse aerosol deposition are compared with individual monodisperse aerosol deposition. Also, total deposition of the polydisperse aerosol is compared with the deposition of the series of monodisperse aerosols forming the same size distribution as the polydisperse aerosol.
Preliminary results indicate that for discrete sections of polydisperse aerosols with particle diameters greater than, or equal to 3 m, there is no difference in deposition when compared with monodisperse aerosols. For particle diameters less than, or equal to 1 m, deposition of discrete sections of polydisperse aerosols was greater than those of monodisperse aerosols. As a result, total deposition was slightly greater for polydisperse aerosols than a series of monodisperse aerosols. Further investigation of these results is underway.
This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.