Degradation of Atenolol with Electrochemical Oxidation at Mixed Metal Oxide Electrodes Assisted by UV Photolysis

Electrochemical oxidation has drawn considerable research attention for the destruction of organic contaminants. This study utilizes the combination of electrolysis and the UV photolysis process to degrade the beta-blocker atenolol (ATL). The results show that the combination of electrolysis and UV photolysis is superior to a single process alone based on the removal rates of ATL and electrical efficiency per order (EE/O). In situ electrogenerated chlorine is confirmed to be responsible for ATL degradation with NaCl electrolytes, and mixed metal oxide (MMO) anodes play a more significant role in the generation of active chlorine than platinum (Pt) anodes. Moreover, reactive species (hydroxyl radical (OH)-O-center dot and chlorine radical Cl-center dot) mainly contributed to ATL degradation during the photo-electrolysis process. Increasing the concentration of NaCl electrolytes and applied current densities can enhance the ATL degradation. Finally, major intermediate products are identified, and a possible degradation pathway of ATL is proposed during the photo-electrolysis processes. This study demonstrates that the photo-electrolysis process can be considered as a potential technology for the destruction of pharmaceutical pollutants in water.