Positive Feedback between Partitioning of Carbonyl Compounds and Particulate Sulfur Formation during Haze Episodes
Year: 2024
Type: article
Abstract: Carbonyl compounds are important precursors of aqueous aerosols in the atmosphere, while their gas-particle partitioning behaviors and roles in particulate sulfur formation are poorly understood. In this study, we investigate the partitioning of five carbonyl compounds (formaldehyde, acetaldehyde, acetone, glyoxal, and methylglyoxal) during haze episodes in Beijing, China. On haze days, the values of field-derived effective Henry’s law coefficients ( K H f ) on aerosols for these carbonyl compounds are 10 6 –10 8 M atm –1, which are significantly higher (10 2 –10 4 times) than those in pure water. Sulfate is observed to have a pronounced “salting-in” effect on these carbonyl compounds, resulting in at least 1-order-of-magnitude increase in their particle-phase concentrations. Parameterization schemes for their partitioning in the ambient aerosols were provided and applied to the multiphase chemical box model (RACM2-CAPRAM). When incorporated into the field-derived parametrization, the model significantly increased hydroxymethanesulfonate (HMS) production by 50-fold compared to using the parameters obtained in pure water, increasing from 2.6 × 10 –2 to 1.23 μg m –3 h –1 . The formed HMS can facilitate sulfate formation in turn through further oxidation by OH radicals and enhance aerosol hygroscopicity. These findings indicate a positive feedback loop between the partitioning of carbonyl compounds and particulate sulfur formation during haze episodes, providing new insights for controlling particulate pollution and reducing SO 2 levels in urban areas.
Institutions: Shandong University, Peking University
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: bronze
Funders: Shandong University, National Natural Science Foundation of China, China Postdoctoral Science Foundation, Natural Science Foundation of Shandong Province, Peking University, Taishan Scholar Project of Shandong Province, Natural Science Fund for Distinguished Young Scholars of Shandong Province
OpenAlex ID: W4404228129