Electrochemical systems equipped with 2D and 3D microwave-made anodes for the highly efficient degradation of antibiotics in urine

This work focuses on the importance of choosing a suitable electrochemical cell to remove antibiotics from urines. For this purpose, we investigate the use of two electrochemical cells for electrolysis and photo-electrolysis of urine polluted with a mixture of Penicillin G, Meropenem, and Chloramphenicol. The two reactors studied were a conventional flow pass electrochemical cell (E-cell) and a microfluidic flow-through reactor (MF-Reactor). Both reactors are equipped with a mixed metal oxide anode (MMO-RuO2IrO2) produced by hybrid heating using microwaves. The MMO coating was deposited on a Ti plate for the E-cell (2-D electrode) and on a Ti foam for the MF-Reactor (3-D electrode). Results demonstrate that the MF-Reactor stands out to reduce two important factors in electrochemical oxidation, the ohmic resistance associated with the microfluidic concept and the mass transfer limitations associated with the flow-through configuration. Moreover, it allows operating at a lower effective current density because of its larger active anodic surface area. Photo-electrolysis results in faster removal of all antibiotics studied in the MF-Reactor and E-cell, compared to the single electrolysis, thereby highlighting the significance of UV light-mediated electrochemical oxidation processes. This work highlights that despite the large number of papers focused on the selection of suitable electrodes for the electrochemical treatment of different types of wastes, the choice of the electrochemical cell can be even more important than the selection of those electrode materials, and it demonstrates that even using the same coating as the anode, highly different outcomes can be reached. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study highlights the importance of selecting a suitable electrochemical cell for removing antibiotics from urine, with the microfluidic flow-through reactor showing superior performance in electrochemical oxidation. Photo-electrolysis results in faster removal of all antibiotics studied, emphasizing the significance of UV light-mediated electrochemical oxidation processes.