HR: 15:15h
AN: A53B-06    [Abstracts]
TI: The atmospheric photooxidation of gaseous PAHs on water films
AU: * Valsaraj, K T
EM: valsaraj@lsu.edu
AF: Louisiana State University Department of chemical engineering, S Stadium Drive, Baton Rouge, LA 70803, United States
AU: Chen, J
EM: jchen6@lsu.edu
AF: Louisiana State University Department of chemical engineering, S Stadium Drive, Baton Rouge, LA 70803, United States
AB: The processing of organic chemicals such as PAHs in fog can lead to more harmful oxy- and nitro-PAHs. Hence, the photo-transformation of gas phase PAHs (e.g. Naphthalene and phenanthrene) is important to understand in the atmospheric environment. This work summarizes our work on the uptake and UV-photo-oxidation of these gas phase PAHs in thin water films such as occurring in fogs and aerosols. A flow tube reactor was used to carry out these reactions. The rate of photo-oxidation was substantially higher in a thin film as compared to a bulk phase reaction1. Several products were identified in the water films and the mechanism of photo-oxidation was assessed. The presence of a natural surfactant in the water led to multiple effects on the rate of reaction. These were characterized via a dual mechanism of self-sensitized and surfactant-sensitized pathways for reaction. The atmospheric implications of these observations will be explored in this paper.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0317 Chemical kinetic and photochemical properties
DE: 0320 Cloud physics and chemistry
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly