The Relationship Between Volatile Organic Profiles And Emission Sources In Ozone Episode Region
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Y.C. Hsu, J.H. Tsai & C.Y. Yang
The relationship between volatile organic profiles and emission sources in ozone episode region Y.C. Hsu1, J.H. Tsai2 & C.Y. Yang2 1 Department of Environmental Engineering and Health, Tajen Institute of Technology, Taiwan. 2 Department of Environmental Engineering, National Cheng-Kung University, Taiwan. Abstract This study investigates the relationship between volatile organic profiles in the atmosphere and emission sources in ozone episode region. Dynamometer and industrial stacks sampling work in the industrial complex were conducted to obtain the 'fingerprints of vehicle emissions and stationary sources. In addition, full-scale field sampling on the main VOC concentration in monitoring stations using USEPA method TO- 14a on photochemical and nor-photochemical event days were done by canisters. The contributions of VOC emissions from different sources were also estimated by back-trojectory model and chemical mass balance model (CMB 8.0). Field measurement data indicate that the daily average concentrations of total VOCs were 87.3-233.7~8 /m3 at different sites. The values of mass fraction for paraffin, oleffin and aroqatic VOCs at these sites were 28-47%, 7-12%, and 41- 52%, respectively. Toluene is the dominant species aqong the VOCs and is followed by isopentane, n-butane, and 1,2,4-trimethylbefizene. For the city and suburban monitoring stations, the exhausts of vehicle are the major contributors of VOC in southern Taiwan. The contributions of total non-methane hydrocarbon (t-NMHC) for CMB simulation are respectively 28-5 1%, 9-24%, 14-33%, 13-46% and 0.1-2.4% from passenger cars, motorcycles, industrial sources, coatings (solvent) and biogenic contributions among all stations. The proportions of biogenic contribution was similar to the overseas researches and being an outstanding characteristic at noon.