ENVR 251 |
| Andrew Ryzhkov, Bertrand J. Revenaz, and Parisa Ariya. Department of Atmospheric and Oceanic Sciences, and Chemistry, McGill University, 805 Sherbrooke Street West, Montreal, QC H3A 2K6, Canada |
| Production of oxidants during winter was long assumed to be much less significant than summer, as photochemistry is reduced. In search for non-photochemically generated sources of oxidants in both gas and liquid phases during late fall and winter we carried out a box modelling study in which ozonolysis reactions of mainly anthropogenically produced alkenes were included. Our results depict that a large amount of HOx, H2O2 and organic peroxides can be formed in the gas phase via these reactions, which can thereby be transported into the liquid phase. These reactions appear to be the major aqueous phase source of hydrogen peroxide. This increase in HOx, H2O2 and organic peroxides efficiently enhances the oxidation of sulfur (IV) to sulfur (VI) in sulfate aerosols. Thus, contrary to traditional chemistry, the oxidation power in the dark seasons of the year, in both gas and liquid phases, may be larger than so far considered. The impact of the ozonolysis of alkenes does not appear to be merely limited to close vicinity of the alkene source under conditions used in this study and, hence, the impact of these reactions should be considered in large scale modelling. |
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Physicochemical Processes in Environmental Systems: A Symposium in Honor of Professor Walter J. Weber, Jr
6:00 PM-8:00 PM, Wednesday, September 10, 2003 Javits Convention Center -- North Pavillion, Poster
Division of Environmental Chemistry |