[Degradation Mechanism of Tetracycline Using Fe/Cu Oxides as Heterogeneous Activators of Peroxymonosulfate].

A green, highly efficient, and porous copper-ferrite heterogeneous catalyst (Fe-Cu-400) with good magnetism was synthesized via a coprecipitation method. The catalysts were characterized using XRD, BET, FESEM, and EDS. The performance of Fe-Cu-400 as a catalyst was evaluated by activating peroxymonosulfate (PMS) for degradation of tetracycline (TC) in aqueous solution and investigating the influence of several water parameters. The Fe-Cu-400/PMS system showed a greater TC degradation ability, and the degradation rate of TC was enhanced with an increase in the PMS concentration and the initial pH of the coupled Fe-Cu-400/PMS system. Anions including HPO, HCO, and Cl promoted TC degradation, whereas NO showed a low inhibitory influence. In addition, Fe-Cu-400 exhibited excellent reusability towards activating PMS for TC degradation after five runs of tests. Possible mechanisms of the activation of PMS by Fe-Cu-400 and the main reactive species were proposed based on radical identification tests and XPS analysis. Furthermore, a potential degradation pathway was proposed that included hydrolysis and sequential removal of -methyl, hydroxyl, and amine functional groups according to the results of LC-MS and TOC detections.