Catalytic degradation of oxytetracycline via FeVO4 nanorods activating PMS and the insights into the performance and mechanism

In this work, FeVO4 nanorods were successfully synthesized and employed as peroxymonosulfate (PMS) activators for oxytetracycline (OTC) degradation. The obtained FeVO4 nanorods exhibited excellent catalytic performance for PMS activation because of the synchronous transformations of Fe3+/Fe2+, V5+/V4+ and Fe3+/V4+, and abundant adsorbed oxygen (Oads). Almost 100% of OTC can be decomposed via FeVO4 activating PMS in 40 min and the reaction rate constant (k) was 0.1073 min−1, being 5.65 times of commercial Co3O4 (0.0219 min−1). Meanwhile, FeVO4 exhibited a good stability and reusability. In addition, the impacts of experimental parameters (catalysts and PMS dosage, temperature, pH, and co-existing anions) on OTC degradation were detected in detail. It was proved that •O2−, •OH and 1O2 were generated and the contribution role in OTC degradation followed the sequence” •OH > 1O2 ≈ •O2−. The possible mechanism of PMS activation by FeVO4 was deeply explored and the OTC degradation pathway was deduced according to the detected degradation intermediates. This study develops one new environmental-friendly, low cost, high efficiency and stable PMS activator for the efficient removal of antibiotics.