Electrochemical Degradation of Paracetamol from Water by Catalytic Action of Fe[sup 2+], Cu[sup 2+], and UVA Light on Electrogenerated Hydrogen Peroxide

Acidic aqueous solutions of the drug paracetamol have been degraded by anodic oxidation and indirect electro-oxidation methods using an undivided electrolytic cell with a Pt anode and an -diffusion cathode for electrogeneration. Anodic oxidation yields low mineralization due to the limited production of oxidant hydroxyl radical from water oxidation at Pt. The presence of as catalyst, with and without (ultraviolet A, UVA) irradiation, slightly enhances the degradation process. In electro-Fenton, much more is produced from Fenton's reaction between added and electrogenerated , but stable complexes are formed. These species are partially photodecomposed in photoelectro-Fenton under UVA irradiation. The use of and yields fast decontamination because complexes are destroyed. Total mineralization of paracetamol is achieved when , , and UVA light are combined. The influence of current, pH, and drug concentration upon the efficiency of catalyzed methods is studied. Hydroquinone, -benzoquinone, and carboxylic acids, such as ketomalonic, maleic, fumaric, oxalic, and oxamic, are detected as intermediates. The positive synergetic effect of all catalysts is explained by the oxidation of -oxalato and -oxamato complexes with , along with the photodecarboxylation of -oxalato and -oxamato complexes by UVA light. and are released during drug mineralization.