標題: Development of an Automated System (PPWD/PILS) for Studying PM2.5 Water-Soluble Ions and Precursor Gases: Field Measurements in Two Cities, Taiwan
作者: Li, Ziyi
Liu, Yingshu
Lin, Yujie
Gautam, Sneha
Kuo, Hui-Chuan
Tsai, Chuen-Jinn
Yeh, Huajun
Huang, Wei
Li, Shih-Wei
Wu, Guo-Jei
環境工程研究所
Institute of Environmental Engineering
關鍵字: PM2.5;Automated measurement system PPWD/PILS;Inorganic ions;Precursor gases;Seasonal variation;Diurnal variation
公開日期: 1-二月-2017
摘要: An automated system consisting of a particle-into-liquid sampler (PILS) and a parallel plate wet denuder (PPWD) coupled with an ion chromatography was used for simultaneous measurement of ambient water-soluble ions in PM2.5 and precursor gases. The performance of the PPWD/PILS was validated by comparing it with the PDS (porous metal denuder sampler) for precursor gases (NH3, HONO, HNO3 and SO2) and PM2.5 ionic species (NH4+, NO3-, SO42-, Na+, Cl- and K+) measured in Taipei and Hsinchu Cities of Taiwan. Good correlations were demonstrated with linear regression slopes ranging from 0.92 to 1.04 and 0.84 to 0.97 as well as R-2 ranging from 0.76 to 0.83 and 0.89 to 0.94, for precursor gases and PM2.5 ions, respectively. The accuracy of the current system for precursor gases outperforms the other commercial systems. Field continuous data showed that NH3 was the most abundant precursor gas with the diurnal pattern peaking at low nocturnal boundary heights and during rush hours with local traffic emissions in Taipei, and with the pattern peaking only at mid-day associated with regional sources in Hsinchu. A reverse diurnal pattern for HONO in Taipei reflected the daytime photolysis and its nocturnal heterogeneous reaction, while its concentration was relatively constant at very low level in Hsinchu. SO42-, NH4+ and NO3- exhibited very similar diurnal patterns with the mean concentrations of 4.56 +/- 3.14, 1.55 +/- 1.16 and 0.52 +/- 0.5 mu g m(-3) in Taipei, and 7.95 +/- 5.52, 2.41 +/- 1.95 and 0.96 +/- 1.10 mu g m(-3) in Hsinchu, respectively. Correspondingly high concentrations of major ions to precursor gases were associated with the photochemical secondary aerosol formations and heavy traffic in Taipei. Based on an ammonia-rich atmosphere and high SOR values, (NH4)(2)SO4 and NH4NO3 were inferred to be the dominant inorganic salts in PM2.5 at both sites, which were also verified by the ion balance analysis.
URI: http://dx.doi.org/10.4209/aaqr.2016.10.0440
http://hdl.handle.net/11536/144731
ISSN: 1680-8584
DOI: 10.4209/aaqr.2016.10.0440
期刊: AEROSOL AND AIR QUALITY RESEARCH
Volume: 17
起始頁: 426
結束頁: 443
顯示於類別:期刊論文