Oxidation of Atmospheric Humic Like Substances by Ozone: A Kinetic and Structural Analysis Approach

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• 作者：Christine Baduel ; Maria E. Monge ; Didier Voisin ; Jean-Luc Jaffrezo ; Christian George ; Imad El Haddad ; Nicolas Marchand ; Barbara D鈥橝nna
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：June 15, 2011
• 年：2011
• 卷：45
• 期：12
• 页码：5238-5244
• 全文大小：876K
• 年卷期：v.45,no.12(June 15, 2011)
• ISSN：1520-5851

文摘

This work explores the heterogeneous reaction between HUmic-LIke Substances (so-called HULIS) and ozone. Genuine atmospheric HULIS were extracted from aerosol samples collected in Chamonix (France) in winter and used in coated flow tube experiments to evaluate heterogeneous uptake of O₃ on such mixtures. The uptake coefficient (纬) was investigated as a function of pH (from 2.5 to 10), O₃ concentration (from 8 to 33 脳 10¹¹ molecules cm^鈥?), relative humidity (20 to 65%) and photon flux (from 0 to 1.66 脳 10¹⁵ photons cm^鈥? s^鈥?). Reactive uptake was found to increase in the irradiated experiment with pH, humidity and photon flux. The extract was characterized before and after exposure to O₃ and/or UV light in the attempt to elucidate the effect of the photochemical aging. Carbon content measurements, UV鈥搗is spectroscopy and functional groups analysis revealed a decrease of the UV absorbance as well as of the carbon mass content, while the functionalization rate (COOH and C鈺怬) and therefore the polarity increased during the simulated photochemical exposure.