MOF-5@Ni Derived ZnO@Ni3ZnC0.7/PMS System for Organic Matter Removal: A Thorough Understanding of the Adsorption–Degradation Process

•ZnO@Ni3ZnC0.7 was successfully synthesized as an effective adsorbent and oxidation catalyst.•Surface hydroxyl groups are the key active sites of both adsorption and degradation.•The degradation process regenerates the adsorption capacity of the catalyst.•Non-radical pathway is the main pathway of degradation in ZN-CS/PMS system.•The magnetic composite can be easily separated and the reusability was verified excellent.