Sulfur Dioxide Accelerates the Heterogeneous Oxidation Rate of Organic Aerosol by Hydroxyl Radicals
| Autor: | Kevin R. Wilson, Allen H. Goldstein, Nicole K. Richards-Henderson |
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| Rok vydání: | 2016 |
| Předmět: |
010504 meteorology & atmospheric sciences
Radical Kinetics 010402 general chemistry Photochemistry complex mixtures 01 natural sciences Redox Troposphere chemistry.chemical_compound Theoretical Models Sulfur Dioxide Environmental Chemistry Organic chemistry Computer Simulation Organic Chemicals Sulfur dioxide 0105 earth and related environmental sciences Aerosols Atmosphere Hydroxyl Radical General Chemistry Models Theoretical respiratory system Hydrocarbons 0104 chemical sciences Aerosol chemistry Alkoxy group Decanoic Acids Oxidation-Reduction Chain reaction Environmental Sciences |
| Zdroj: | Environmental science & technology, vol 50, iss 7 Richards-Henderson, NK; Goldstein, AH; & Wilson, KR. (2016). Sulfur Dioxide Accelerates the Heterogeneous Oxidation Rate of Organic Aerosol by Hydroxyl Radicals. Environmental Science and Technology, 50(7), 3554-3561. doi: 10.1021/acs.est.5b05369. UC Berkeley: Retrieved from: http://www.escholarship.org/uc/item/9hq6r37k |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/acs.est.5b05369 |
| Popis: | © 2016 American Chemical Society. There remains considerable uncertainty in how anthropogenic gas phase emissions alter the oxidative aging of organic aerosols in the troposphere. Here we observe a 10-20 fold acceleration in the effective heterogeneous OH oxidation rate of organic aerosol in the presence of SO2. This acceleration originates from the radical chain reactions propagated by alkoxy radicals, which are formed efficiently inside the particle by the reaction of peroxy radicals with SO2. As the OH approaches atmospheric concentrations, the radical chain length increases, transforming the aerosol at rates predicted to be up to 10 times the OH-aerosol collision frequency. Model predictions, constrained by experiments over orders of magnitude changes in [OH] and [SO2], suggest that in polluted regions the heterogeneous processing of organic aerosols by OH ([SO2] ≥ 40 ppb) occur on similar time scales as analogous gas-phase oxidation reactions. These results provide evidence for a previously unidentified mechanism by which organic aerosol oxidation is enhanced by anthropogenic gas phase emissions. (Chemical Equation Presented). |
| Databáze: | OpenAIRE |
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