Degradation of Ibuprofen by UV-LED/catalytic advanced oxidation process

Ibuprofen (IBP), a widely used anti-inflammatory drug, has been detected in many rivers and lake waters. This study was aimed to degrade the ibuprofen from synthetic wastewater by using UV-LED/catalytic and UV-LED/oxidants advanced oxidation process. The degradation of IBP was investigated with ultraviolet light emitting diode (UV-LED) irradiation in presence of Titanium dioxide (TiO ₂ ), Zinc oxide (ZnO), Hydrogen peroxide (H ₂ O ₂ ), Potassium peroxomonosulfte (PMS) and Potassium peroxodisulfate (PDS). It was observed that the degradation of IBP was directly influenced by the pH of IBP solution, and higher degradation rate was observed at lower pH values. The study on effect of irradiation time showed that both TiO ₂ and ZnO can completely degrade the IBP within 90 min, while H ₂ O ₂ PMS, and PDS degraded 38%, 55%, and 74% IBP respectively. The UV-LED/TiO ₂ system was found to be the most efficient among all selected systems (UV-LED/ZnO; UV-LED/H ₂ O ₂ ; UV-LED/PMS; UV-LED/PDS). The SPME (Solid phase microextraction)/GC–MS was used for the better illustration of Ibuprofen degradation mechanism and to identify generated byproduct in the degradation process. Four byproducts(benzene 1-ethenyl-4-(2-methypropyl), benzene 1-(1-hydroxyethyl)-4-isobutyl, 4′-(2-methylpropyl)acetophenone, ibuprofen methyl ester) were detected after UV-LED catalytic degradation of IBP solution. The present study showed that the UV-LED/catalyst process significantly enhanced the degradation of IBP in comparison to direct photolysis by UV-LED.