High-NOx Photooxidation of n-Dodecane: Temperature Dependence of SOA Formation

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• 作者：Houssni Lamkaddam ; Aline Gratien ; Edouard Pangui ; Mathieu Cazaunau ; Bénédicte Picquet-Varrault ; Jean-François Doussin
• 刊名：Environmental Science & Technology
• 出版年：2017
• 出版时间：January 3, 2017
• 年：2017
• 卷：51
• 期：1
• 页码：192-201
• 全文大小：485K
• ISSN：1520-5851

文摘

The temperature and concentration dependence of secondary organic aerosol (SOA) yields has been investigated for the first time for the photooxidation of n-dodecane (C₁₂H₂₆) in the presence of NO_x in the CESAM chamber (French acronym for “Chamber for Atmospheric Multiphase Experimental Simulation”). Experiments were performed with and without seed aerosol between 283 and 304.5 K. In order to quantify the SOA yields, a new parametrization is proposed to account for organic vapor loss to the chamber walls. Deposition processes were found to impact the aerosol yields by a factor from 1.3 to 1.8 between the lowest and the highest value. As with other photooxidation systems, experiments performed without seed and at low concentration of oxidant showed a lower SOA yield than other seeded experiments. Temperature did not significantly influence SOA formation in this study. This unforeseen behavior indicates that the SOA is dominated by sufficiently low volatility products for which a change in their partitioning due to temperature would not significantly affect the condensed quantities.