Abstract
AbstractSevere events of wintertime particulate air pollution in Beijing (winter haze) are associated with high relative humidity (RH) and fast production of particulate sulfate from the oxidation of sulfur dioxide (SO2) emitted by coal combustion. There has been considerable debate regarding the mechanism for SO2 oxidation. Here we show evidence from field observations of a haze event that rapid oxidation of SO2 by nitrogen dioxide (NO2) and nitrous acid (HONO) takes place, the latter producing nitrous oxide (N2O). Sulfate shifts to larger particle sizes during the event, indicative of fog/cloud processing. Fog and cloud readily form under winter haze conditions, leading to high liquid water contents with high pH (>5.5) from elevated ammonia. Such conditions enable fast aqueous-phase oxidation of SO2 by NO2, producing HONO which can in turn oxidize SO2 to yield N2O.This mechanism could provide an explanation for sulfate formation under some winter haze conditions.
Publisher
Springer Science and Business Media LLC
Subject
General Physics and Astronomy,General Biochemistry, Genetics and Molecular Biology,General Chemistry
Reference57 articles.
1. Sun, J. et al. Investigating the PM2.5 mass concentration growth processes during 2013–2016 in Beijing and Shanghai. Chemosphere 221, 452–463 (2019).
2. Pendergrass, D. C., Shen, L., Jacob, D. J. & Mickley, L. J. Predicting the impact of climate change on severe wintertime particulate pollution events in Beijing using extreme value theory. Geophys. Res. Lett. 46, 1824–1830 (2019).
3. Shen, L., Jacob, D. J., Mickley, L. J., Wang, Y. & Zhang, Q. Insignificant effect of climate change on winter haze pollution in Beijing. Atmos. Chem. Phys. 18, 17489–17496 (2018).
4. Zhao, J. et al. Organic aerosol processing during winter severe haze episodes in Beijing. J. Geophys. Res. Atmos. 124, 10248–10263 (2019).
5. Huang, R. J. et al. Contrasting sources and processes of particulate species in haze days with low and high relative humidity in winter time Beijing. Atmos. Chem. Phys. Discuss. 2020, 1–29 (2020).
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