Mixed metal oxide (Ru, Ir, Sn) electrodes in the anodic activation of peroxydisulfate for a sustainable degradation of rifampicin

Electrochemical advanced oxidation processes (EAOPs) are promising approaches to wastewater purification. Anodic oxidation (AO), due to its ease and cost-efficiency, has attracted rising attention in this research area. Herein, we employ Mixed Metal Oxide (MMO) electrodes, including RuIrSnOx@Ti, RuIrOx@Ti, and RuOx@Ti, to activate peroxydisulfate (PDS) in the anodic activation process. The Rifampicin (RIF) pharmaceutical was selected as the model pollutant to be treated in the proposed electrochemical system. The surface and electrochemical characteristics of the electrodes were characterized to analyze and determine their properties and effectiveness. Also, the various parameters affecting the efficiency of the process, such as the different metal oxide electrodes, PDS/electrolyte/RIF concentration, and the current flow, are optimized. The optimal values for these parameters were determined to be [RIF]0 40 mg/L, I 80 mA, [PDS] 1 mmol/L, and [Na2SO4] 50 mmol/L. The LC-MS and COD techniques were also used to identify electrochemical-induced intermediates and describe a plausible degradation pathway. Finally, the proposed electrochemical system can be considered a simple wastewater purification method through this research.

Keyword: anodic activation; DSA electrodes; electrochemical activation; mixed metal oxides; PDS