O3 based advanced oxidation for ibuprofen degradation

Abstract

The degradation of the anti-inflammatory ibuprofen (IBP) was evaluated by several advanced oxidation processes. IBP was treated by single ozonation and oxidation with hydrogen peroxide (H 2 O 2 ), as well as a combination of these treatments. In order to improve the efficiency, the presence of catalysts such as original carbon nanotubes, labelled as CNT, and iron oxide supported on carbon nanotubes, named as Fe/CNT sample, was considered. The evolution of IBP degradation, mineralization and toxicity of the solutions was assessed. The formation of intermediates was also monitored. In the non-catalytic processes, IBP was faster removed by single ozonation, whereas no significant total organic carbon (TOC) removal was achieved. Oxidation with H 2 O 2 did not present satisfactory results. When ozone and H 2 O 2 were combined, a higher mineralization was attained (70% after 180 min of reaction). On the other hand, in the catalytic processes, this combined process allowed the fastest IBP degradation. In terms of mineralization degree, the presence of Fe/CNT increases the removal rate in the first hour of reaction, achieving a TOC removal of 85%. Four compounds were detected as by-products. All treated solutions presented lower toxicity than the initial solution, suggesting that the released intermediates during applied processes are less toxic.