Publication: Sulfur radical formation from the tropospheric irradiation of aqueous sulfate aerosols
Publication - Sulfur radical formation from the tropospheric irradiation of aqueous sulfate aerosols
Sulfur radical formation from the tropospheric irradiation of aqueous sulfate aerosols
Publication Year: 2022
Author list: JD Cope, KH Bates, LN Tran, KA Abellar, TB Nguyen
Journal Short Name: Proc. Nat. Acad. Sci.
AbstractThe sulfate anion radical (SO4•–) is known to be formed in the autoxidation chain of sulfur dioxide and from minor reactions when sulfate or bisulfate ions are activated by OH radicals, NO3 radicals, or iron. Here, we report a source of SO4•–, from the irradiation of the liquid water of sulfate-containing organic aerosol particles under natural sunlight and laboratory UV radiation. Irradiation of aqueous sulfate mixed with a variety of atmospherically relevant organic compounds degrades the organics well within the typical lifetime of aerosols in the atmosphere. Products of the SO4•– + organic reaction include surface-active organosulfates and small organic acids, alongside other products. Scavenging and deoxygenated experiments indicate that SO4•– radicals, instead of OH, drive the reaction. Ion substitution experiments confirm that sulfate ions are necessary for organic reactivity, while the cation identity is of low importance. The reaction proceeds at pH 1–6, implicating both bisulfate and sulfate in the formation of photoinduced SO4•–. Certain aromatic species may further accelerate the reaction through synergy. This reaction may impact our understanding of atmospheric sulfur reactions, aerosol properties, and organic aerosol lifetimes when inserted into aqueous chemistry model mechanisms.
|ID||Name||Start date||Experiment Category||Reaction Type||Reactant(s)||Oxidant Name||Temperature||Humidity||Type of Seed||RO2 Main Fate||Data Sets (count)||Actions|
|691||Nguyen Group_20211116_2-Methylbut-3-ene-1,2-diol_None_Ammonium sulfate||2021-11-16||Condensed-phase chemical reaction, Multiphase chemical reaction, Aerosol aging||Photooxidation||2-Methylbut-3-ene-1,2-diol||None||20-22||75||Ammonium sulfate||Not Sure||7|
|692||Nguyen Group_20211119_2-Methylbut-3-ene-1,2-diol_None_Ammonium sulfate||2021-11-19||Condensed-phase chemical reaction, Multiphase chemical reaction, Aerosol aging||Photooxidation||2-Methylbut-3-ene-1,2-diol||None||20-22||81||Ammonium sulfate||Not Sure||7|
|693||Nguyen Group_20211122_2-Methylbut-3-ene-1,2-diol_None_Ammonium sulfate||2021-11-22||Volatility and partitioning, Instrument/Chamber characterization, Blank/Control||Non-chemical||2-Methylbut-3-ene-1,2-diol||None||20-22||79||Ammonium sulfate||Not Sure||7|
|694||Nguyen Group_20211129_None_Ammonium sulfate||2021-11-29||Volatility and partitioning, Instrument/Chamber characterization, Blank/Control||Non-chemical||-||None||20-22||84||Ammonium sulfate||Not Sure||7|
|695||Nguyen Group_20211203_None_No Seed||2021-12-03||Volatility and partitioning, Instrument/Chamber characterization, Blank/Control||Non-chemical||-||None||20-22||85||No Seed||Not Sure||4|