| 英文摘要 |
The goals of this project are to measure fine particulate matter (PM2.5) mass and composition, audit the performance of PM2.5 speciation monitoring instruments, and introduce PM2.5 related monitoring technology from leading countries. After completing 63 batches of PM2.5 field measurements, this study compares manual collection with continuous monitoring at the eight air quality monitoring stations (AQS). The mass concentration varies quite consistently but continuous monitoring reads higher. The linear regression correlation coefficients (R2) of PM2.5 mass concentration between continuous monitoring and manual collection of R&P 2000 Federal Reference Method (FRM) reached above 0.86 for all data at the eight AQS. The ratios of PM2.5 mass concentration for R&P 2000 FRM over continuous monitoring ranged from 0.57 to 0.89 with an average of 0.76 for all data at the eight AQS. In addition, the ratios of PM2.5 mass concentration for R&P 2300 speciation sampler over continuous monitoring ranged from 0.87 to 0.92 with an average of 0.90 for all data at the three speciation AQS. For most monitoring stations, seasonal variations were obvious; PM2.5 concentration was highest in spring and lowest in summer. The predominant PM2.5 species was SO42- in spring and fall, while the major PM2.5 species in summer was organic carbon. The concentration of NO3- was highest in spring but with lowest ratio for volatilized NO3- over original NO3-. The trend was reversed for NO3- in summer and fall. For the study of the deviation between R&P 2300 speciation sampler and R&P 2000 FRM, the results show that the installed honeycomb denuders and filter package in R&P 2300 accounted for the deviation between the two samplers. The ratio of the volatilized NO3- to the original NO3- at the three speciation stations was low when the maximum ambient temperature is low; however, the ratio was increased rapidly with the increasing maximum ambient temperature. Nonetheless, the aforementioned ratio varied greatly with the same maximum ambient temperature. The ratio of corrected PM2.5 to original PM2.5 increased about 10% for all data. Although the corrected mass ratio is not great, from pollution source control viewpoint, the assessment of control efficiency for sources emitting precursors of particulate chemical components still needs to be traced back to their ambient particulate component concentrations. Therefore, accurate measurement on particulate component concentration is certainly necessary. For the deviation of PM2.5 concentration between R&P 2300 and the continuous monitoring, this project finds that particle water content has a weak correlation with the deviation. Overall, this project achieved satisfied results for the quality control and quality assurance (QC/QA) of the measurements in PM2.5 mass, water-soluble ions, and carbonaceous content.
This year, the instruments in PM2.5 speciation monitoring stations were merged into ordinary air quality monitoring stations. Only Fu-Yin station keeps the instruments of the original core supersite in operation. For data availability of all speciation monitoring instruments, the best is aerosol light-scattering spectrometer with an average of 95.5%. It is followed by Aethalometer with an average of 92.1% for data availability. The data availability for common instrument such as Sunset 5040 carbon analyzer ranged from 70.6 % to 92.9% with Fu-Yin station stays the best in all stations.
For the aspect of introducing PM2.5 related monitoring technology and the setup of monitoring technology norms, information such as performance comparison among the U.S. FRM, average deviation of FEM from FRM by the U.S. EPA in May 2011, the comparison of the U.S. FRM and FEM, certified PM2.5 FRM and FEM promulgated by the U.S. EPA on 12 October 2011, side by side FRM and FEM data comparison issued from the U.S. EPA on 22 February 2012, introduction of the U.S. Chemical Speciation Network, the impact of aerosol carbonaceous content on environmental change, European CARBOTRAF on the measurements of black carbon and CO2 from vehicle emissions were all compiled. As a companion work, this project completed PM2.5 manual measuring norm, modified data QC/QA operation manual, evaluated the applicability of PM2.5 manual measurement in Taiwan, and suggested future PM2.5 manual measurement sites in Taiwan. Given the promulgation of PM2.5 air quality standard by the Taiwan EPA, this project suggests allowing the application of all U.S. PM2.5 FRM to Taiwan, establishing an acceptable norm between PM2.5 continuous monitors and FRM, planning the setup of Taiwan PM2.5 chemical speciation network, and establishing two major speciation monitoring stations in the southern and northern Taiwan.
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