During　the　conventional　aging　process　of　microplastics,　a　significant　amount　of　oxygen-containing　functional　groups　are　generated,　which　enhances　the　adsorption　capacity　of　aged　microplastics.　In　this　study,　we　constructed　various　electron　beam/strong　oxidant　systems　and　adjusted　the　oxidative　capacity　to　enhance　the　aging　performance　of　polypropylene　while　reducing　its　adsorption　ability.　Experimental　results　indicate　that　as　the　oxidative　capacity　of　the　system　increases,　the　aging　degree　of　polypropylene　significantly　improves,　yet　the　adsorption　performance　for　sulfonamides　exhibits　a　trend　of　initially　decreasing　and　then　increasing.　Conventional　methods　typically　generate　a　large　number　of　oxygen-containing　functional　groups　on　the　surface　of　microplastics.　These　oxygen-containing　functional　groups　enhance　the　adsorption　capacity　for　sulfonamide　pollutants　through　electrostatic　interactions,　hydrogen　bonding,　and　van　der　Waals　forces.　As　we　further　enhance　the　oxidative　capacity　of　the　system,　reactive　free　radicals　continue　to　attack　the　surface　oxygen-containing　functional　groups,　resulting　in　their　removal　and　transformation.　We　determined　for　the　first　time　the　changes　in　the　aging　process　of　microplastics　and　the　surface　oxygen-containing　functional　groups　under　different　oxidative　capacities.　This　breakthrough　reveals　the　nonlinear　relationship　between　oxidation　intensity　and　the　evolution　of　surface　functional　groups.　At　low　oxidation　intensities,　reactive　radicals　preferentially　attack　and　remove　oxygen-containing　functional　groups,　thereby　decreasing　the　sites　for　pollutant　adsorption.　In　contrast,　at　high　oxidation　intensities,　the　restructuring　of　functional　group　structures　facilitates　a　rebound　in　adsorption　performance.　This　mechanism　systematically　clarifies　the　longstanding　＇aging-adsorption＇　vicious　cycle,　providing　theoretical　support　for　the　precise　regulation　of　microplastic　aging　pathways.　©　2025　Elsevier　Inc.