Enhanced UV Direct Photolysis and UV/H2O2 for Oxidation of Triclosan and Ibuprofen in Synthetic Effluent: an Experimental Study

da Luz, Vilson Conrado; Bazoti, Suzana Fátina; Behling, Laura; Dalla Rosa, Clarissa; Pasquali, Gean Delise Leal

Enhanced UV Direct Photolysis and UV/H2O2 for Oxidation of Triclosan and Ibuprofen in Synthetic Effluent: an Experimental Study

2022

da Luz, Vilson Conrado | Bazoti, Suzana Fátina | Behling, Laura | Dalla Rosa, Clarissa | Pasquali, Gean Delise Leal

This study aimed to evaluate the implementation of an advanced oxidation system based on UV radiation and UV/H₂O₂ for degradation of TCS and IBU in synthetic effluent. The assays occurred in a 2-L reactor, protected from external light and equipped with a UV lamp (λ = 254 nm). The effect of contaminant concentration, fractions of chemical species present, and mineralization were evaluated. In the UV/ H₂O₂ system, different concentrations of H₂O₂ were studied for oxidation of the contaminants. The kinetic experiments took place between 75 and 270 min of UV irradiation. The results showed > 99% oxidation of TCS in the direct photolysis system at pH 9.4 after 12 min. The degradation of IBU in the UV/H₂O₂ system, when 10 mg L⁻¹ of H₂O₂ was used, was 97.39% oxidation. We obtained k′ values of 0.189 min⁻¹ for TCS when its highest oxidation occurred and k′ values of 0.0219 min⁻¹ for IBU. The system was not able to completely mineralize the contaminants, presenting high values of TOC and COD after treatment, thus suggesting the occurrence of phototransformation.

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