Water Soluble Ions in Atmospheric Coarse/Fine Particlesaround a Semiconductor Science and Industrial Park

• Main Authors: Wang , Wei-Chih, 王偉志
• Other Authors: Hsieh, Lien-Te
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/42cs4r

碩士 === 國立屏東科技大學 === 環境工程與科學系所 === 105 === This study focuses on the characteristics of water soluble ions in the coarse (PM2.5-10) and fine particles (PM2.5) around a semiconductor industrial area. The sampling periods were classified into episode (abbreviated as E, PM2.5>35 μg/m3; Nov. 11–13, 2015 (E1) and Jan. 18–21 (E2)) and non-episode days (abbreviated as NE, PM2.5≤35 μg/m3; Apr. 18–21, 2016). All atmospheric day-/night-time particulate samples were collected by dichotomous samplers (Dichot) at three stationary sites, which were located on the roof of a semiconductor plant and a public air quality monitoring station in the industrial park in southern Taiwan. The PM2.5 and PM2.5-10 samples were further determined for their atmospheric concentrations and the compositions of water-soluble ions.Results showed that, during both episode and non-episode days, the concentrations of PM2.5 and PM2.5-10 in the ambient air significantly increased. The daytime episode/non-episode ratios (E1/NE and E2/NE) for PM2.5 were 1.29 and 1.81, respectively, while for PM2.5-10 the data were 1.43 and 1.50, respectively. On the other hand, the nighttime E1/NE and E2/NE ratios for PM2.5 were 1.56 and 2.32, respectively, while for PM2.5-10 they were 1.79 and 2.53, respectively. At all three sampling sites, the PM2.5 and PM2.5-10 concentrations during daytime were higher than those during nighttime by 24~37% (30% in average) and 11~49% (33% in average), respectively. PM2.5 dominated over 65% of PM10 mass concentration in ambient air during both episode and non-episode days. The dominant water-soluble ions in PM2.5 were NO3-, SO42-, and NH4+ during E1, E2, and NE; however, they were NO3-, SO42-, Cl- and Na+ in PM10. The above major ions were sourced from the secondary aerosol (NO3-, SO42-, and NH4+) around the nearby urban area, while Cl- and F- were mainly from the semiconductor production industries. Consequently, the total ionic contents on atmospheric PM2.5 and PM2.5-10 were 34.1–65.9 (53% in average) and 25.5–72.1% (48% in average), respectively, while the sum of NO3-, SO42-, and NH4+ contributed 70–98% (90% in average) and 41–83% (67% in average) mass of total ionic species in PM2.5 and PM2.5-10, respectively.