Different Weathering Strategies Result in Different Surface Properties and Adsorption Behavior in Aged Microplastics

/g for ozone and UV aging. Isotherm experiments with phenanthrene showed a decrease in adsorption with surface oxidation, while, for 9-phenanthrol, adsorption was higher for UV- and ozone-aged MPs than pristine MPs and declined for the highly oxidized persulfate-aged MPs. These results demonstrate that different oxidation strategies produce structurally and functionally distinct MPs, highlighting the importance of the aging protocol in laboratory studies.