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• Electronic polarization and defect engineering modification enhanced intrinsic PMS activation. • ACO-O V @PES membrane/PMS system achieved flow-through removal of contaminants. • The highly accessible SO 4 ·−, · OH, and 1O 2 were the responsible reactive species. • DFT calculations revealed PMS activation promotion by dual-modification strategy. The application of Fenton-like membrane reactors for water purification offers a promising solution to overcome technical challenges associated with catalyst recovery, reaction efficiency, and mass transfer typically encountered in heterogeneous batch reaction modes. This study presents a dual-modification strategy encompassing electron polarization and defect engineering to synthesize Al-doped and oxygen vacancies (O V)-enriched Co 3 O 4 spinel catalysts (ACO-O V). This modification empowered ACO-O V with exceptional performance in activating peroxymonosulfate (PMS) for the removal of organic contaminants. Moreover, the ACO-O V @polyethersulfone (PES) membrane/PMS system achieved organic contaminant removal through filtration (with a reaction kinetic constant of 0.085 ms−1), demonstrating outstanding resistance to environmental interference and high operational stability. Mechanistic investigations revealed that the exceptional catalytic performance of this Fenton-like membrane reactor stemmed from the enrichment of reactants, exposure of reactive sites, and enhanced mass transfer within the confined space, leading to a higher availability of reactive species. Theoretical calculations were conducted to validate the beneficial intrinsic effects of electron polarization, defect engineering, and the confined space within the membrane reactor on PMS activation and organic contaminant removal. Notably, the ACO-O V @PES membrane/PMS system not only mineralized the targeted organic contaminants but also effectively mitigated their potential environmental risks. Overall, this work underscores the significant potential of the dual-modification strategy in designing spinel catalysts and Fenton-like membrane reactors for efficient organic contaminant removal. [Display omitted] [ABSTRACT FROM AUTHOR]

• A novel synergistic technology coupling ultrasound and CNTs/PM (UCP) was developed. • Electron-rich organics could be rapidly removed in the UCP process from raw water. • RMnS oxidation and electron transfer were the main processes for CIP removal. • Ultrasound and CNTs played a critical role in promoting the generation of free RMnS. • CNTs could maintain satisfactory efficiency after repeated use in the UCP process. Recently, free reactive manganese species (RMnS) generated via permanganate catalytic oxidation technology has been applied to contaminants abatement and sludge dewatering. This study proposed a novel free RMnS generation method in ultrasound enhanced carbon nanotube (CNTs)/permanganate process (UCP) for organics removal. Taking ciprofloxacin as a target contaminant, the removal efficiency in the UCP process (9.78 s−1) was remarkably higher than that of the permanganate (0.71 s−1) and CNTs/permanganate (2.57 s−1) processes. CNTs could enrich manganese compounds and ciprofloxacin, and act as an electronic platform for the electronic transfer from ciprofloxacin to manganese compounds for free RMnS generation, which was revealed by DFT calculation and spectrum analysis. Meanwhile, ultrasound further regulated the generation of RMnS as it could transform the inactive solid Mn(IV) into free RMnS. In the UCP process, non-free radical modes including RMnS oxidation (49.8%) and electron transfer (23.5%) were the dominant processes for ciprofloxacin removal in the UCP process, and hydroxyl radical oxidation (13.2%), CNTs adsorption (5.5%), and PM oxidation (8.0%) also contributed to ciprofloxacin removal. Interestingly, CNTs could be well reused in the UCP process as more than 88.75% of ciprofloxacin was removed after five times reuse of CNTs. The UCP process provides a novel strategy for rapid contaminants removal in water treatment via continuous generation of free RMnS. [Display omitted] [ABSTRACT FROM AUTHOR]