Removal of the anti-inflammatory drug ibuprofen from water using homogeneous photocatalysis

Abstract

In this paper the photocatalytic degradation of the 0.2mM ibuprofen (2-(4-(2-methylpropyl)phenyl)propanoic acid) in aqueous solution (pH 3) has been carried out by the homogeneous photocatalysis (photo-Fenton) process. This method consists of coupling Fenton's reagent and UV-C irradiation in order to catalyse the in situ generation of hydroxyl radicals, a powerful oxidizing agent which leads to degradation of organic pollutants until total mineralization. The effect of H2O2 and Fe3+ (catalyst) concentration on the TOC removal has been examined and the performances of photo-Fenton process have been also compared with other photochemical processes such as direct photolysis (UV alone) and H2O2 photolysis (H2O2/UV). The results have shown that the photo-Fenton process appeared more effective than the other systems studied and the TOC removal decreased in the sequence: photo Fenton>H2O2/UV>UV alone. The kinetics study showed that the TOC removal follows the second-order kinetics. It was found that the concentrations of H2O2 and ferric iron constitute key factors governing the TOC removal and that the optimal concentrations are equal to 10mM of H2O2 and 0.25mM Fe3+. In these conditions, 96% of initial TOC has been removed after 8h of irradiation time.