Constrained Heterogeneous CoFe₂O₄/ZnO/PMS Fenton‐Like System for Industrial Wastewater Remediation with Recyclability and Zero Metal Loss

Abstract Although heterogeneous Fenton‐like processes have attracted widespread attention in wastewater treatment, the mass leached active ions lead to secondary pollution and confuse the demarcation of reaction region. By constructing a constrained completely heterogeneous system and highlighting its reaction region concentrated within the slipping plane of particles, this work achieves efficient organic pollutants degradation without leaching of any free active metal components. Based on the Poisson–Boltzmann equation and electric double layer model, the specific existing of the constrained region is confirmed, and this neglected reaction region between solid interface and slipping plane in traditional heterogeneous Fenton‐like reaction is clarified firstly. Due to the unique constrained property, this system demonstrates exceptional potentials application to natural water and actual industrial wastewater for its broad resistance to environmental interference. Furthermore, the alkalization aging process enables this system achieve catalyst recycle and zero metal ions emission with maintaining outstanding pollutants removing performance even in high‐salt wastewater, exhibiting the superiority of the constrained completely heterogeneous system. This work demonstrated the important reaction region within slipping plane and provided a clearer boundary in heterogeneous Fenton‐like system.