| Summary: | 碩士 === 國立屏東科技大學 === 環境工程與科學系 === 91 === Samples in this study were collected by using both an annular denuder system（ADS）and a manual dichotomous（Dichot）simultaneously 24 hours per month from August 2002 to May 2003. The ADS was used to collect gases such as SO2, HNO2, HNO3 and NH3. The Dichot was used to collect the PM2.5 and PM2.5-10 in day and night. The particulate concentration and gaseous composition in Chao-Chou were investigated. The results revealed that the levels of PM2.5, PM2.5-10 and PM10 were ranged for 16.2-124, 11.1-64.9 and 38.7-168.3, respectively. Mass Concentration for PM2.5, PM2.5-10 and PM10 were accounted for 57.0±27.1, 35.4±12.8 and 92.4±32.7, respectively. This result indicates that the suspension particulates in Chao-Chou were dominated by PM2.5 (about 60%) during the sampling days. The majority of composition in PM2.5, PM2.5-10 and PM10 were water-soluble ions.Secondary aerosols such as SO4-2, NO3-, and NH4+ were accounted for 64% in water-soluble ions. These results indicate that the secondary aerosols were major composition in water-soluble ions. Experiments results revealed that the A/C values in PM2.5 were higher than 1.0. The A/C values in both PM2.5-10 and PM10 were lower than 1.0. The neutralization ratio（NR）for PM2.5, PM2.5-10 and PM10 were accounted for 1.31±0.63 , 0.77±0.73 and 1.04±0.48, respectively. This result indicated that both PM2.5 and PM10 were in the basic situation. However, the NR for PM2.5-10 showed that PM2.5-10 was in the acidic situation. During the sampling period, the sulfur oxidation ratio（SOR）and nitrogen oxidation ratio（NOR）were 0.52±0.16 and 0.17±0.07 for day time, 0.77±0.13 and 0.17±0.07 for night time, respectively. Both long transportation and local emission were the major contribution to PM10. The [HNO3]/ [NO3-] ratios in spring and summer were higher than in autumn and winter due to the high equilibrium constant of NH4NO3 in high temperature condition. The [SO2]/ [SO4-2] and [NH4+]/（[NO3-]+[SO4-2]）ratios in spring and summer were lower than in autumn and winter due to the gas-phase oxidation SO2 to sulfate by strong photochemical reaction in high temperature condition. With NH4+ and NO3- decreasing, that the [NH4+]/（[NO3-]+[SO4-2]）ratio decreases. The Dichot samples were conducted qualitative analysis by FTIR. Strong absorption peaks such as NH4+, Cl-, NO3- and SO4-2 were observed in both fine and coarse particle spectra in autumn and winter. Above results suggest the secondary pollutants such as (NH4)2SO4, NH4NO3, NH4Cl and NH4HSO4 were highly correlated to the concentration profiles of paticulates.
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