Degradation of ofloxacin by lanthanum cerate perovskite activated bisulfite

Abstract

In recent years, the extensive utilization of ofloxacin (OFX) has led to elevated concentration of OFX compound in the aquatic environment. At the same time, the inherent recalcitrance of OFX has presented a formidable challenge for OFX degradation. In this study, lanthanum cerium perovskite (LaCeO3) was prepared by citric acid sol–gel method to activate bisulfite (BS) for the effective degradation of OFX. The results revealed that the LaCeO3/BS system removed 87.5% of OFX within 180 min with a pseudo-first-order kinetic constant of 3 × 10−3 min −1. Radical quenching experiments and electron paramagnetic resonance (EPR) spectroscopy confirmed that sulfate radicals (SO4•_) and hydroxyl radicals (HO•) were the primary reactive species responsible for OFX removal in LaCeO3/BS system. The reaction mechanism indicated that Ce in LaCeO3/BS system served as the primary active site for BS activation, and a regenerating cycle involving ≡Ce(III)/≡Ce(IV) was present. Additionally, possible intermediate products were identified by a liquid chromatograph-mass spectrometer (LC-MS), revealing potential degradation pathways of OFX. Cycle tests and energy dispersive spectrometer (EDS) data demonstrated the favorable reusability and stability of LaCeO3.