Electrochemical degradation of antiviral pharmaceutical oseltamivir in water: A comparative study of BDD and DSA electrodes

Pharmaceutical contamination in aquatic environments is an increasing concern due to the persistence of these compounds and their incomplete removal in conventional wastewater treatment plants. While many studies focus on antibiotic removal, antiviral pharmaceuticals remain understudied. Oseltamivir (Tamiflu) is the most prescribed influenza antiviral, representing the 99.8% of antiviral prescriptions in the United States in 2010–2019. Its extensive use during the COVID-19 pandemic increased environmental accumulation. Electrochemical oxidation emerges as competitive solution to remove this persistent compound from water. This study examines oseltamivir degradation and mineralization via electrochemical oxidation with boron-doped diamond (BDD) anode and dimensionally stable anodes (DSA) by varying current density and initial drug concentration using Na 2 SO 4 or NaCl as supporting electrolyte. Treatment key performance indicators were assessed in terms of oseltamivir degradation and total organic carbon removal. The evolution of generated final carboxylic acids and released nitrogenated ions, including nitrate, nitrite, and ammonia, was followed as well. Results showed that BDD achieved overall degradation and significantly higher mineralization efficiency of oseltamivir than DSA in sulfate solutions because of its greater hydroxyl radical generation. In contrast, DSA exhibited greater oxidation power than BDD in chloride medium, where the attack with generated active chlorine dominated. This study demonstrates strong potential of electrochemical oxidation for antiviral pharmaceutical removal, supporting its development with DSA anode for sustainable water treatment applications in chloride media.