Acidic aerosol concentrations measured by an annular denuder system (ADS) and a honeycomb denuder system (HDS) in Hsinchu, Taiwan, were compared. Aerosols were also sampled by a MOUDI (micro-orifice uniform deposit impactor) and analyzed by an ion chromatograph to determine the size distributions of different species. Using the measured aerosol size distribution, theoretical analysis showed that positive HNO3 artifact due to volatiliza-tion of NH4NO3 is generally negligible for both samplers.4 3Comparing two different denuder samplers, the average concentration of HNO3 measured by the ADS was found3to be lower than that measured by the HDS, while the difference between the two samplers for the average concentration of other species was found to be within ±15%. A possible cause of the difference in HNO3 con-3centrations is due to a greater loss of HNO3 in the cyclone3 used by the ADS than in the impactor used by the HDS. The study also showed incomplete absorption of the evaporated HCl and HNO3 from the particles on the Teflon3filter by the first nylon filter in the filter pack of the ADS. Collection efficiency and capacity of HCl and HNO3 by3the nylon filters need further investigation.
|Number of pages||9|
|Journal||Journal of the Air and Waste Management Association|
|State||Published - 1 Jan 2000|