Biochar-supported Fe/Mg co-doped MoS₂ synergistically enhances PMS activation for the degradation of tetracycline hydrochloride: A study on the Fe²⁺/Fe³⁺ cycling driving mechanism and catalytic stability

Due to its high efficiency, safety, and low economic cost, peroxymonosulfate (PMS) advanced oxidation processes (AOPs) are widely used for removing organic pollutants from wastewater. In this study, an environmentally friendly porous biochar was prepared from waste wood powder generated in the building materials industry through simple pyrolysis, and iron-magnesium oxide with high catalytic activity, stability, and low cost was loaded as the active center. Mo ions were added to create a ternary composite catalyst. At room temperature, a 0.5 g/L catalyst concentration and 5 mM PMS achieved a 98.22% removal of 20 mg/L tetracycline hydrochloride within 2 minutes, with complete degradation occurring within 60 minutes. The catalytic degradation rate exceeded 93.76% across a pH range of 3-10, demonstrating broad pH adaptability. Recycle tests showed that the degradation rate of tetracycline hydrochloride was 87.38% after 9 cycles, confirming the catalyst's recyclability and reusability. This addresses the current challenge of low catalyst utilization, enabling the efficient removal of organic pollutants quickly while reducing production costs and process time. The high catalytic performance, recyclability, wide pH range, and low ion leaching rate of the catalyst in antibiotic wastewater treatment highlight its broad application potential as a PMS activator, offering a new approach to catalyst design for advanced oxidation degradation of antibiotic pollutants PMS.