Abstract
This study aims to investigate the mechanism of synthesized Mn-Fe(3)O(4) catalysts in the deep degradation of COD in sauce-flavored liquor wastewater by heterogeneous Fenton oxidation. Additionally, the study evaluates the impact of operational factors, including pH, catalyst composition, and dosage on the COD removal rate. The physicochemical characteristics of Mn-Fe(3)O(4) catalysts were comprehensively analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The oxidation mechanism of the Mn-Fe(3)O(4) heterogeneous Fenton system was elucidated through gas chromatography-mass spectrometry (GC-MS) analysis, kinetic modeling, and radical quenching experiments involving tert-butanol (TBA) and benzoquinone (BQ). The results demonstrated that the Mn-Fe(3)O(4)-based system enhanced COD removal by 26% compared to the conventional Fenton process, exhibiting remarkable stability and magnetic recoverability. The catalyst system followed second-order kinetics, with the dual Mn-Fe active centers on the catalyst surface facilitating electron transfer via charge redistribution, promoting redox cycling of Fe(2+)/Fe(3+) and Mn(2+)/Mn(3+), and significantly increasing hydroxyl radical (·OH) production, thereby enabling the efficient degradation of refractory organic pollutants. This study provides valuable insights for the development of innovative catalytic materials for the effective treatment of industrial wastewater containing phenolic quinones, which are challenging to degrade, and sets the stage for further industrial applications.