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-H(2)O(2) oxidation) were executed to evaluate the isolated effects and additional differentiated degradation pathways of IBP. The solar photolysis cleavage of H(2)O(2) generates hydroxylated-IBP byproducts 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 H(2)O(2) 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 BOD(5) of 25 mg L(-1) was reached in contrast to the initial BOD(5) shown by the untreated IBP solution (BOD(5)<1 mg L(-1)). The increase in the biodegradability of the photo-Fenton degradation byproducts opens the possibility for a complete remediation with a final post-biological treatment.
Méndez-Arriaga
Fabiola
F
Departamento de Ingeniería Química, Facultad de Química, Universidad de Barcelona, C/ Martí i Franquès 1, 08028 Barcelona, Spain. fmendeza@ub.edu
Esplugas
Santiago
S
Giménez
Jaime
J
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis* / Q000737:chemistry; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005618:Fresh Water / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007052:Ibuprofen / Q000032:analysis* / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
D000894:Anti-Inflammatory Agents, Non-Steroidal; C045076:Fenton's reagent; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; D007501:Iron; D007052:Ibuprofen