Polymeric removal of phenolic compounds in acetylperoxyl radical-mediated oxidation processes

Oxidative polymerization is an unrecognized yet critical pathway in CH 3 CO 3 • -mediated AOPs. • Polymerization contributes ∼20–65% to phenolics removal depending on substituent merits. • CH 3 CO 3 • -driven polymerization process works efficiently in saline and real coking wastewater. • Recovered polymers can be valorized as functional porous carbon materials with high surface area. The acetylperoxyl radical (CH 3 CO 3 • )-based advanced oxidation processes (AOPs) have been widely employed for organic contaminant elimination, with existing studies predominantly attributing pollutant removal to mineralization or fragmentation pathways. However, the contribution of oxidative polymerization triggered by CH 3 CO 3 • has been systematically overlooked. Herein, by taking the widely-studied CH 3 CO 3 • -based oxidation system (i.e., Co 2+ /PAA), we demonstrated that oxidative polymerization constitutes a critical pathway, accounting for 12.2–61.4% of phenolic contaminants removal in CH 3 CO 3 • -driven AOPs depending on the substituent merits. Through systematic analysis of the transformation of phenol during the oxidation and comprehensive characterization of recovered solid polymers, we confirmed the formation of solid-state polymers in the Co 2+ /PAA system. Thermodynamic calculations further validate the feasibility of polymerization mechanisms, identifying hydrogen abstraction (HAA) as the predominant initiation step. Notably, this oxidative polymerization phenomenon persists in complex aqueous matrices and real coking wastewater systems, demonstrating environmental relevance. Importantly, the harvested polymeric solids exhibit potential for valorization as precursor materials for porous carbon synthesis, achieving surface areas as high as 635.7 m 2 /g with promising catalytic performance. This work uncovers a previously neglected but significant polymerization pathway in the CH 3 CO 3 • -based AOPs, establishing a sustainable avenue for phenolic wastewater purification. Oxidative polymerization, which has been largely overlooked in CH 3 CO 3 • -mediated AOPs, constitutes a critical route for removing electron-rich phenolic compounds, accounting for ∼20–65% of contaminant elimination depending on substituent characteristics. The CH 3 CO 3 • -driven polymerization process proves effective for treating phenolic industrial wastewater. It enables simultaneous phenolic contaminant removal and the recovery of solid polymer products, which can be further valorized as precursors for porous functional carbon materials. Download: Download high-res image (171KB) Download: Download full-size image