中部空品區大氣氣膠中水溶性離子微粒之特性探討

• Main Authors: Mei-Lun Huang, 黃美倫
• Other Authors: Man-Ting Cheng
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/27250402541169194335

碩士 === 國立中興大學 === 環境工程學系 === 89 === Eight sampling sites in the Central Taiwan were chosen to collect PM2.5 and PM2.5-10 samples from August 1999 to March 2000. Sampling stations included Wuchi coastal station, Chunglun and Changhwa urban stations, Tsaotun, Nanton, Chushan, Puli, Shuantung and Peishan stations in the inland area. In this research, dichotomous samplers were used to collect aerosol samples during daytime and nighttime period. Water-soluble ionic species in particulate phase were analyzed with ion chromatography. Aerosol data were then evaluated with air-quality and meteorological data in order to investigate the seasonal and the spatial variations of sulfate, nitrate and ammonium particulates in the Central Taiwan. Results showed that average PM10 concentrations in autumn and winter were about two times higher than those in summer. PM2.5 concentrations were usually greater than those of PM2.5-10. However coarse particulate matters (PM2.5-10) increased significantly in spring 2000 due to the influence of the prevailing Asian dust storms. Sulfate accounted for 6 % to 12 % of PM10. Distributions of sulfate were relatively uniform in the Central Taiwan as compared with those of nitrate. Sulfate concentrations measured in 1999 ~ 2000 were lower than those obtained in 1997 ~ 1998. Reduction of SO2 emissions from the Taiwan Electric Power Plant during this period might influence the local ambient sulfate concentrations. On the contrary, nitrate concentrations were 0.3 ~ 4.5 % higher. Particularly, the concentrations of nitrate and NO2 increased significantly during PM10 episodes in the autumn and winter, probably due to the traffic related emissions. Ammonium displayed similar spatial variation of sulfate. PM10 concentrations in the inland areas were found higher than those in the coastal and the urban areas. Such variations may be attributed to lower wind speed in the inland area. Although higher wind speed was often recorded at the coastal site, SO2 and sulfate percentage in PM10 were apparently higher as compared with the other sites in Central Taiwan. These results provided evidence for the role of the Electric Power Plant in the high emission levels in the coastal area .