Electrochemical degradation of antibiotic levofloxacin by PbO2 electrode: Kinetics, energy demands and reaction pathways

In this work, the electrochemical degradation of antibiotic levofloxacin (LFX) has been studied using a novel rare earth La, Y co-doped PbO 2 electrode. The effect of applied current density, pH value and initial LFX concentration on the degradation performance were systematically evaluated. The results demonstrated that electrochemical oxidation of LFX over the La-Y-PbO 2 electrode was highly effective and the reaction followed an apparent first-order kinetic model. Considering the degradation efficiency and energy efficiency, the relative optimal conditions are identified as current density 30 mA cm −2 , pH 3 and initial LFX concentration 800 mg L −1 . According to the identified products, a reaction mechanism has been proposed and the products were further oxidized to CO 2 , H 2 O, NH 4 + , NO 3 − and F − . A total of four aromatic intermediate products of LFX degradation were identified and the different structural changes to the LFX molecule included pepiperazinyl hydroxylation, decarboxylation and defluorination .