| Summary: | 碩士 === 國立中興大學 === 環境工程學系所 === 97 === Government will build a Central Taiwan Science Park in Erlin area and may also build a Power Plant in Lukang area in the future. In order to investigate the characteristics of aerosol particles and to understand the sources of the aerosol pollutants in these areas, we had used the High Volume Air Samplers were used to collect PM2.5 and PM2.5-10 aerosols at Lukang and Erlin sampling sites. The sampling experiments were conducted during the periods from 11/24-12/7 in 2008 and 4/27-5/3 in 2009. The samples were then further analyzed for water soluble ions, elemental carbon, organic carbon by using ion chromatograph and elemental analyzer. Finally a chemical mass balance receptor model was used to evaluate the source contributions.
Experimental results showed the major fraction in the ambient particles was contributed by fine particles in these areas. The particulate mainly consisted of sulfate, nitrate, ammonium and carbonaceous components. During the PM2.5 episodic events, the PM2.5 concentrations in these two places increased about 2.4 times as compared to those in normal days. Among the increased species, nitrate concentrations increased 4.4 times. The significant increase of nitrate contents might be contributed by the vehicle emissions. In the analysis of sulphur oxidation ratio, the sulphur oxidation ratios of PM2.5 obtained in Erlin area in winter were higher than those in Lukang area.
The results obtained by using the CMB modeling showed a similar pattern on the source contributions to PM2.5 and PM2.5-10 for these two areas. Vehicle emissions, sulphate and nitrate were the major sources for PM2.5. But for PM2.5-10, the major sources were crustal materials, vehicle emissions and marine spray. Therefore the sources of PM10 mainly attributed from vehicle emissions, sulphate and nitrate. During winter season, the high wind speed easily caused the wind-blown soil dust. Thus, a large portion of source contributions came from crustal materials. On the contrary, the wind speed was relatively lower in spring, and the pollutants were poorly dispersed. Therefore, the major sources were sulphate and nitrate. The results showed that the average concentration of nitrate during the PM2.5 episodic periods was 3 times higher than that obtained during non-episodic days. The data also showed a river dust event occurred on the fifth of December in Erlin area. In this event, the crustal elements contributed the major fraction in PM2.5-10, and were about 4 times higher than those observed during the normal days.
|
|---|
