Performance of different advanced oxidation technologies for the abatement of the beta-blocker metoprolol

In this study UV/H2O2, photo-Fenton and photocatalysis (TiO2) were used to degrade metoprolol tartrate salt (MET) in aqueous solution. This study investigates the variation of different parameters such as MET concentration, total organic carbon (TOC), chemical oxygen demand (COD) per accumulated energy (determined by actinometries), analyzing the performance of the different set-ups tested. First order apparent rate constants were calculated for the systems. Nearly total MET removal was achieved through the three technologies tested, the UV/H2O2 system being more efficient for MET degradation. On the other hand, the kinetic study indicated that TiO2 photocatalysis seems to be one step ahead of the others when assessing the mineralization and the overall oxidation of the solution for a specific amount of accumulated energy (18 kJ/L). The acute toxicity measured by the inhibition percentage of bioluminescence from Vibrio fischeri indicates that all the processes tested promote the toxicity reduction for this target compound. The major reaction intermediates in the three processes were identified by ionization/mass spectrometry. (C) 2014 Elsevier B.V. All rights reserved.