Activate hydrogen peroxide for efficient tetracycline degradation via a facile assembled carbon-based composite: Synergism of powdered activated carbon and ferroferric oxide nanocatalyst

Magnetic carbon@ferroferric oxide nanocatalyst (C@FONC), a composite material comprising powdered activated carbon (PAC) and ferroferric oxide nanocatalyst (FONC), was prepared using chemical co-precipitation. In this study, we evaluated the performance and complete pathway of tetracycline (TC) degradation in a C@FONC/H2O2 system. Moreover, the toxicity of TC and its intermediates was estimated. TC degradation in the C@FONC/H2O2 system followed pseudo-first-order kinetics, and the TC removal efficiency reached 97% in 120 min (TC0 = 150 ppm). The electron spin resonance (ESR) analysis and free radical quenching experiments indicated the generation of center dot OH and HO2 center dot during the reaction. The investigation of the reaction mechanisms revealed the complementary performances between C@FONC adsorption and heterogeneous Fenton-like reaction in the TC degradation process. The stability of C@FONC recycling was also measured by multiple cycles of reactions, and the TC removal rate still reached 85.8% after nine cycles. In addition, the superparamagnetism and negligible iron leaching of the C@FONC/H2O2 system represented significant improvements relative to PAC and the conventional homogeneous Fenton process, making it a promising composite for applications in advanced oxidation processes.