Catalytic Ozonation of Environmentally Relevant Pharmaceuticals Using Oxygen- and Nitrogen-Doped Activated Carbons

Catalytic ozonation is one of the advanced oxidation processes (AOPs) that have yielded promising results in the treatment of emerging pollutants, in which the catalyst plays a fundamental role. In this study, surface oxygen and nitrogen groups were introduced onto two commercial activated carbons, and their catalytic activity in the ozonation of lamotrigine, carbamazepine, and ibuprofen was evaluated. The modified activated carbons were characterized by N2 adsorption at −196 °C, elemental analysis, thermogravimetric analysis (TGA) and determination of the pH at the point of zero charge (pHpzc). The by-products formed in the catalytic ozonation of the compounds with each catalyst were identified, and the mineralization of the pollutants was determined. Finally, the catalysts that showed the best mineralization of the individual compounds were used for testing with the mixture of pharmaceutical contaminants. These catalysts reduced the total organic carbon (TOC) of the mixture by over 74% after 180 min of reaction. The mineralization of pollutants was improved by catalysts with higher nitrogen content and fewer surface oxygenated acid groups.