Magnetically Enhanced Fenton-Like Processes by Nanofibers: Real-Time Observation of Tetracycline Degradation in Pig Manure Wastewater

This study presents a novel approach for the degradation of tetracycline (TC) in pig manure wastewater using magnet-ite-based magnetic nanofibers (MNFs) as heterogeneous Fenton-like catalysts. The MNFs, composed of polyacrylonitrile (PAN) embedded with MnFe_2O_4 nanoparticles, were synthesized via electrospinning and exhibited high stability and catalytic efficiency. The degradation process was driven by hydroxyl radical (OH) formation through hydrogen peroxide (H2O2) activation on the MNF surface. The results showed that TC was first adsorbed onto the MNFs before undergoing oxidation, with treatment efficiency increasing with H2O2 concentration up to an optimum point, due to increased OH scavenging by H_2O_2. A heterogeneous dynamic kinetic model (DKM) was developed to describe the degradation mechanism, incorporating reactive oxygen species (ROS) generation, catalyst surface inactivation, and polymer strip-ping effects. Furthermore, the application of an alternating magnetic field significantly accelerated the reaction rate, likely due to localized heating effects. This study highlights the potential of MNFs as a scalable, reusable and efficient alternative for antibiotic-contaminated wastewater treatment, offering advantages over conventional homogeneous Fenton processes by minimizing iron sludge formation and broadening the operational pH range.