Résumé
Performic acid (PFA), widely recognized for its disinfectant properties in wastewater, shows selective and limited reactivity in oxidizing micropollutants. This study investigates the activation of PFA through UV-C photolysis to generate an advanced oxidation process (UV-C/PFA) and enhance the degradation of six pharmaceuticals: lidocaine, furosemide, sulfamethoxazole, diclofenac, acetaminophen, and carbamazepine. The synergy of UV-C photolysis with PFA enhances the removal of PFA-persistent pharmaceuticals. For instance, diclofenac, acetaminophen, and sulfamethoxazole, initially unreactive with PFA, were entirely degraded within ten minutes under UV-C/PFA in a phosphate buffer solution. This increased reactivity results from generated reactive species like hydroxyl (HO•), peroxyl (R-O•) radicals and singlet oxygen (1O2), confirmed by electron paramagnetic resonance, with HO• primarily originating from the background H2O2 present in the PFA solution. While UV-C/ PFA produced fewer HO• than UV-C/H2O2, it has distinct advantages through the selective action of 1O2 and R-O• in degrading some pharmaceuticals. 1O2 was also detected in the PFA solution and could explain its selective reactivity, especially with compounds containing reduced sulfur or tertiary amine groups. Overall, UV-C/ PFA yields transformation products of lower molar mass compared to PFA, thus potentially increasing mineralization. In wastewater effluent, UV-C/PFA improved pharmaceutical degradation, though scavenging effects by wastewater constituents reduced removal rates.