Degradation and Mineralization of Ibuprofen Using Electrochemical Advanced Oxidation Processes Combined with Ozone

Pharmaceuticals and personal care products (PPCPs) are difficult to degrade through conventional wastewater treatment processes and have been confirmed to enter rivers, raising concerns regarding their impacts not only on aquatic organisms but also on humans and terrestrial ecosystems. In this study, the decomposition and mineralization of ibuprofen (IBP), a nonsteroidal anti-inflammatory drug, were investigated using some electrochemical advanced oxidation processes (sulfate radicals, hydroxyl radicals derived from ozone reduction, and the electro-peroxone method (with and without external ozone)). Two supporting electrolytes, NaClO4 and Na2SO4, and four electrode configurations, boron-doped diamond (BDD)/Pt, Pt/Pt, BDD/glassy carbon (GC), and Pt/GC, were compared with and without external ozone addition. IBP was completely degraded under all ozone-assisted conditions and in systems employing GC cathodes which produce the electro-peroxone reaction, whereas electrolysis without external ozone required the electro-peroxone reaction to achieve comparable removal. External ozone accelerated IBP degradation, and complete decomposition was achieved more rapidly than in the ozone-free systems. Mineralization, evaluated by total organic carbon removal, was highest in the external ozone-assisted BDD/Pt system with NaClO4 and improved further when Na2SO4 was used, suggesting an additional contribution from sulfate radicals. Specifically, after 300 min, mineralization reached 86% for BDD/Pt + O3 and 55% for BDD/Pt without external ozone in Na2SO4, while the Pt-anode systems achieved 72% with ozone and 37% without ozone, demonstrating the effectiveness of external ozone-assisted treatment. These results indicate that external ozone-assisted electrochemical oxidation can substantially enhance the degradation and mineralization of IBP, while reducing the dependence on expensive BDD anodes.