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Updated: Jun 27, 2026
09:31
Preparation of Authigenic Pyrite from Methane-bearing Sediments for In Situ Sulfur Isotope Analysis Using SIMS
Published on: August 31, 2017
Atmospheric microplastics amplify sulfate formation via heterogeneous SO2 oxidation
Xinyuan Xiong1, Siya Kuang1, Jingmeng Lei2
1College of Chemistry, Central China Normal University, Wuhan 430079, PR China; Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction, Ministry of Education, PR China.
Journal of Hazardous Materials
|June 25, 2026
Summary
Photochemically aged microplastics (MPs) accelerate atmospheric sulfur dioxide (SO2) oxidation. Environmentally persistent free radicals (EPFRs) on aged MPs activate oxygen, significantly increasing sulfate formation, especially with interfacial water.
Area of Science:
- Atmospheric chemistry
- Environmental science
- Materials science
Background:
- Atmospheric microplastics (MPs) are ubiquitous pollutants.
- Photochemical aging of MPs generates environmentally persistent free radicals (EPFRs).
- EPFRs on MPs can catalyze redox reactions, but their atmospheric role is unclear.
Purpose of the Study:
- To investigate the role of UV-aged polystyrene (PS) MPs in atmospheric chemical processes.
- To elucidate the mechanism of SO2 oxidation on aged MP surfaces.
- To understand the contribution of MPs to secondary aerosol formation.
Main Methods:
- Exposure of PS MPs to UV radiation to simulate aging.
- Characterization of surface functional groups and EPFRs on aged MPs.
- Experimental assessment of SO2 uptake and oxidation on pristine and aged MPs.
- Analysis of sulfate formation yields under varying relative humidity.
Main Results:
- UV-aged PS MPs exhibit enhanced reactivity as interfacial media.
- Surface EPFRs and oxygen-containing groups facilitate O2 activation to superoxide radicals (O2•⁻).
- Aged PS MPs significantly accelerate SO2 heterogeneous oxidation, increasing sulfate yields up to 2.3 times.
- High relative humidity enhances SO2 oxidation via interfacial water-promoted reactive oxygen species generation.
Conclusions:
- Photochemically aged MPs act as catalysts for atmospheric SO2 oxidation.
- EPFRs-mediated oxygen activation is a key mechanism driving enhanced sulfate formation.
- MPs play a synergistic role in atmospheric oxidation and secondary aerosol formation.
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