Fe₃O₄ nanoparticles three-dimensional electro-peroxydisulfate for improving tetracycline degradation

In this work, Fe₃O₄ nanoparticle employed as the three-dimensional electrode, were introduced into the electro-oxidation system with peroxydisulfate to improve the tetracycline (TC) degradation. The coprecipitation method prepared Fe₃O₄ was proved to be the irregular sphere-like form through the characterizations of XRD, SEM, N₂ adsorption isotherms, and XPS. By the contrast experiments, the EO-Fe₃O₄-PDS exhibited the outstanding TC degradation capability, which achieved 86.53% after 60 min treatment with current intensity of 20 mA cm^-2, Fe₃O₄ dose of 0.2 g L^-1, PDS amount of 2 mmol L^-1, initial pH 4.5, and TC concentration of 25 mg L^-1. Besides, the influence of current intensity, Fe₃O₄ dosage, PDS concentration, and beginning pH on the TC degradation was investigated systemically. The consecutive five recycles of Fe₃O₄ demonstrated that a favorable stability for the coupling process. The EO-Fe₃O₄-PDS could improve the PDS decomposition and H₂O₂ production. The sulfate and hydroxyl radicals both took charge of the antibiotic degradation as certified by scavenger test. The TC degradation evolution was presented based on the HPLC-MS analyses of degradation byproducts.