Recovery and reuse of alkaline battery residues for Ti/RuO2-MnO2-ZnO electrode synthesis and electrochemical degradation of venlafaxine

Electrochemical Advanced Oxidation Processes (EAOPs) have emerged as promising technologies for the removal of emerging contaminants in aquatic environments. The technical and environmental feasibility of these processes strongly depends on the selection and application of efficient, stable, and sustainable anode materials. This study reports the development of mixed metal oxides (MMOs) anodes supported on metallic titanium, using MnO 2 and ZnO nanomaterials obtained from metals recovered from alkaline batteries, and their application for venlafaxine degradation. The structural properties of the synthesized electrodes were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), which confirmed the formation of the oxides (i.e., RuO 2 , ZnO, and MnO 2 ) used in producing the binary and ternary MMOs evaluated in this study: Ti/(RuO 2 ) 70 -(ZnO) 30 , Ti/(RuO 2 ) 70 -(MnO 2 ) 30 and Ti/(RuO 2 ) 30 -(MnO 2 ) 35 -(ZnO) 35 . Electrochemical characterization revealed that the ternary anode, composed of ZnO, MnO 2 and RuO 2 , exhibited a higher electroactive surface area and improved stability compared to the binary anodes. The electrocatalytic performance of the anodes was evaluated during the electrochemical oxidation of venlafaxine, where the ternary anode Ti/RuO 2 -MnO 2 -ZnO recorded the highest degradation (99%) and mineralization (99%) rates after 90 min of electrolysis. These findings point to a reliable and sustainable route for the production of MMOs derived from recycled metals in alkaline batteries, highlighting their great application potential for the treatment of water and wastewater containing pharmaceutical pollutants.