A Study of the Characteristic of Acidic Aerosols at a Monitoring Station in Taipei
|關鍵字:||固氣分離器;酸性氣膠;氨氣;粗微粒和細微粒;氫離子和硫酸根離子濃度比值;annular denuder system;acidic aerosols;ammonia;fine and coarse particles;H+/SO42-|
The characteristics of acidic aerosols in Taipei, Taiwan were investigated in this study. The application of annular denuder/filter pack system (ADS) made it possible to collect gases in the denuder tubes and particles at the after filters simultaneously. ADS2.5 and ADS10, were used in the study. The cutoff aerodynamic diameters for the inlet cyclones of ADS2.5 and ADS10 are 2.5 μm and 10 μm respectively. The main particulate components of acidic aerosols were found, to be NH4+,SO42-,NO3-, and Cl-. The elevated concentrations of NH3 were found to neutralize particles, resulting in reduction of acidity of aerosols in Taipei. The acidity of aerosols is represented by hydrogen ions (H+) concentration in the aerosols. The ratio of H+/SO42- gives a good index of chemical compositions in sulfate acidic aerosols. In Taipei, sulfate aerosols were normally found to exist as (NH4)2SO4 and letovicite. The particulate and gaseous concentrations were found to be higher in spring than in other seasons except for those of Cl- ions. The correlation of species concentrations of ADS2.5 and ADS10 with criteria pollutant concentrations obtained from the Taiwan EPA (Environmental Protection Agency) monitoring station were found to be significant in general.
|Appears in Collections:||Thesis|