Integrated regeneration of pharmaceutical-loaded biochar via desorption and electrochemical oxidation of the regenerant solution

This study investigates the removal and degradation of pharmaceutical compounds commonly found in hospital effluents through a hybrid wastewater treatment approach that combines adsorption onto sustainable materials with electrochemical oxidation processes. A commercial biochar was first ground and chemically activated with an alkaline solution to enhance its adsorption capacity toward two model pharmaceuticals: levofloxacin and meropenem. After saturation of the adsorbent, several desorption solutions were tested to regenerate the biochar by removing the adsorbed contaminants from its surface. The concentrated regenerant solution obtained during the desorption step was subsequently treated by electrochemical oxidation using boron-doped diamond (BDD) and mixed metal oxide (MMO) anodes, aiming for the complete degradation of the pharmaceutical compounds. Finally, both the regenerated biochar and the electrochemically treated solution were reused in a new adsorption/desorption cycle to assess the efficiency and reusability of the proposed hybrid system. The expected outcomes of this study contribute to the development of sustainable and integrated technologies for hospital wastewater treatment, reducing the environmental impact associated with pharmaceutical residues.