Degradation of sulphamethazine by means of an improved photo-Fenton process involving a hydrogen peroxide systematic dosage

Despite being acknowledged as an emerging contaminant, sulphamethazine (SMT) degradation has received scarce attention in the advanced oxidation processes field. Thus, this work addresses the degradation of SMT in water solutions (12L of 25mgL(-1) samples) by means of a photo-Fenton process and a systematic H2O2 dosage protocol that enhances its performance. A conventional photo-Fenton process led to 86% mineralization after 120min treatment when adding the Fenton reactants at once (initial concentrations were 10mgL(-1) Fe(II) and 200mgL(-1)H(2)O(2)). Conversely, the process achieved the total mineralization of the samples in less than 75min when the same amount of H2O2 was continuously dosed according to a conveniently tuned dosage protocol. In both cases, total SMT degradation was achieved within 10min. Hence, this work's aim is to determine the efficient dosage conditions of H2O2. The results show that a significant improvement of the photo-Fenton mineralization of SMT solutions is possible by adjusting the dosage of H2O2.