Heterogeneous sulfate radical-based advanced oxidation process for the efficient pharmaceutical wastewater treatment: Performance, practicability, and mechanism.

Magnetic ferrospinel nanoparticles have significant advantages for the oxidative degradation of recalcitrant organic contaminants during wastewater treatment. In this study, a sulfate radical-based oxidation process was conducted using multiwalled carbon nanotubes (CNT) decorated with ferrospinel CoFe2O4 (CFO) nanoparticles to catalyze peroxydisulfate (PDS) for the efficient degradation of tetracycline (TC) and pharmaceutical wastewater. CNT played a critical role in enhancing the catalytic activity of CFO to activate PDS, enabling rapid degradation (100 %, kobs = 0.347 min-1) and mineralization (62.8 %) of TC (20 mg/L) within 30 min of catalytic oxidation. Recycling tests demonstrated the high stability of the as-prepared nanocomposite with minimal leaching of metal ions during the oxidation reactions. The degradation mechanism was elucidated, implying that both radical (HO•, SO4•-, and O2•-) and non-radical (1O2) species contributed significantly to TC degradation over the CNT@CFO/PDS system. When combined with other chemical oxidants, CNT@CFO exhibits noticeable catalytic activity, indicating a high potential for application in the purification of pharmaceutical wastewater. This study develops a valuable insight into water purification through the integration of adsorption and catalytic oxidation advantages in PDS activation. The results of this study demonstrate a feasible and easy approach for the preparation of magnetically recoverable catalysts with exceptional efficacy, which can be used for the efficient decontamination of antibiotics in aqueous solutions.