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

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 (lambda = 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.