Study on the electrochemical removal mechanism of oxytetracycline by a Ti/IrO2-Ta2O5 plate

Abstract

In this study, a Ti/IrO2-Ta2O5 anode was prepared by a hydrothermal method, and the prepared electrode was characterized by techniques such as scanning electron microscopy, X-ray diffraction, and electron dispersive spectroscopy. At the same time, the anode characteristics before and after electrochemical experiments were analyzed. The electrode gradation mechanism of oxy-tetracycline is discussed. In the whole experimental process, the range of electrolysis conditions was determined by single factor experiment, and then the optimal removal condition of oxytetracycline was determined by orthogonal experiments. The removal rate of oxytetracycline reached 99.02% after 20 min of electrolysis under the following optimal conditions: a current of 0.500 A, plate spac-ing of 2 cm, Na2SO4 electrolyte concentration of 4 g/L, and solution pH of 3. Additionally, the mechanism of oxytetracycline removal was explored, free radical scavenging experiments were per-formed, and the degradation mechanism was inferred based on the changes in the ultraviolet ab-sorption of the oxytetracycline solution before and after electrolysis. Then, based on the liquid chro-matography–mass spectrometry data, seven possible compounds and five possible removal path-ways were proposed.