Characterization of Ambient Aerosol in the Vicinity of Semiconductor Plants

• Main Authors: Yi-Chen Chen, 陳羿辰
• Other Authors: Shui-Jen Chen
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/66648744309971533321

碩士 === 國立屏東科技大學 === 環境工程與科學系所 === 97 === This study was conducted from September, 2008 to June, 2009 at a semiconductor plant in a science park in southern Taiwan to understand the characteristics of ambient atmospheric aerosol in the vicinity of semiconductor plants. There were six sampling sites: ground, roof of the plant building (48.9 m high), northeast ambient (5 m high), southwest ambient (16 m high), and outside of Science Park (background). Dichot samplers were used daytime (08:00~17:00) and nighttime (17:00~8:00 the second day) to collect the coarse and fine aerosols quarterly. Besides, water-soluble ions of the particles (F-, Cl-, Br-, NO3-, SO42-, PO43-, Na+, NH4+, K+, Mg2+, Ca2+) and carbon contents (EC and OC) were analyzed. The results showed that during the studied period, the PM10 concentration from high to low was southwest ambient (80.8±27.5 μg/m3) > top of the plant building (68.4±23.1 μg/m3) > background A (66.4±29.4 μg/m3) > up-wind ambient (59.4±20.6 μg/m3) > ground site (53.0±16.0 μg/m3) > background B (41.4±11.3 μg/m3). The PM2.5/PM10 ratios at the plant building roof (0.61±0.10) were higher than those at the ambient northeast and southwest sites (0.52±0.0 and 0.49±0.09, respectively). About 60% of the aerosols on the roof of plant building were fine-sized particles. About half (0.44–0.49) of atmospheric PM2.5 at the park center (plant building top and ground sites) and northeast/southweat ambient were water-soluble ions and the ratio was the highest on the top of plant building (0.49±0.07). However, only about one third (0.26–0.31) of coarse aerosols (PM2.5-10) were water-soluble ions. The concentrations of F-, Cl-, Br-, SO42-, and NH4+ of PM2.5 and PO43- of PM2.5–10 on the plant building roof were significantly higher than those of northeast/southwest ambient and background. This phenomenon was related to the emission of materials used in the semiconductor plants. The carbon content (EC + OC) of PM2.5 was about 35 % (0.33–0.36) at the park center and ground and northeast/southwest ambient. Moreover, the particulate EC and OC were primarily in fine particles (PM2.5). The OC content (23%) was double higher than that of EC (10%) for both coarse and fine particles. The ground atmospheric NMHC concentrations in the science park were greater than those recorded by an air quality monitoring station of Taiwan EPA. This phenomenon is possibly related to the organic solvents used and volatile organic compounds (VOCs) fugitive in semiconductor manufacturing processes.