Degradation of the emerging contaminant ibuprofen in water by photo-Fenton

In this study the degradation of the worldwide Non-Steroidal Anti-Inflammatory Drug (NSAID) ibuprofen (IBP) by photo-Fenton reaction by use of solar artificial irradiation was carried out Non-photocatalytic experiments (complex formation, photolysis and UV/Vis-H2O2 oxidation) were executed to evaluate the isolated effects and additional differentiated degradation pathways of IBP. The solar photolysis cleavage of H2O2 generates hydroxylated-IBP by products without mineralization Fenton reaction, however promotes hydroxylation with a 10% contamination in form of a mineralization in contrast photo-Fenton in addition promotes the decarboxylation of IBP and its total depletion is observed in absence of H2O2 a decrease of IBP was observed in the Fe(II)/UV-Vis process due to the complex formation between iron and the IBP-carboxylic moiety The degradation pathway can be described as an interconnected and successive principal decarboxylation and hydroxylation steps TOC depletion of 40% was observed in photo-Fenton degradation The iron-IBP binding was the key-point of the decarboxylation pathway Both decarboxylation and hydroxylation mechanisms, as individual or parallel process are responsible for IBP removal in Fenton and photo-Fenton systems An increase in the biodegradability of the final effluent after photo-Fenton treatment was observed Final BOD5 of 25 mgL(-1) was reached in contrast to the initial BOD5 shown by the untreated IBP solution (BOD5 < 1 mgL(-1)) The increase in the biodegradability of the photo-Fenton degradation by products opens the possibility for a complete remediation with a final post-biological treatment (C) 2009 Elsevier Ltd All rights reserved