Electrochemical removal of amoxicillin using a Cu doped PbO 2 electrode: Electrode characterization, operational parameters optimization and degradation mechanism.

This work investigated the electrochemical degradation of amoxicillin (AMX) in aqueous solution with Cu-PbO ₂ electrode. The main influence factors on the degradation of AMX, such as Na ₂ SO ₄ concentration, initial AMX concentration, current density and initial pH value, were analyzed in detail. Under the optimal conditions, the removal rates of AMX and chemical oxygen demand (COD) reached 99.4% and 46.3% after 150 min treatment. The results indicated that the electrochemical degradation of AMX fitted pseudo-first-order reaction kinetics. Compared with undoped PbO ₂ electrode, Cu-PbO ₂ electrode had a smaller crystal size, more proportion of hydroxyl oxygen species, greater AMX and chemical oxygen demand (COD) removal efficiency, higher average current efficiency (ACE) and lower electrical efficiency per log order (EE/O). Electrochemical oxidation using Cu-PbO ₂ electrodes was an effective way to eliminate amoxicillin in aqueous solution. Moreover, a possible degradation pathway including ring open and mineralization was proposed by intermediate products determined by GC-MS method. This paper could provide basic data and technique reference for the amoxicillin wastewater pollution control.
(Copyright © 2019. Published by Elsevier Ltd.)