Application des complexes organiques dans les procédés d’oxydation avancée pour la dégradation des polluants pharmaceutiques en solution aqueuse.

Abstract

The catalytic activation of hydrogen peroxide (H2O2), persulfate (PS) and peroxymonosulfate (PMS) by organometallic FeIII and CuII complexes has been applied in the removal of several types of pharmaceutical pollutants in aqueous solution. The catalytic treatment processes were performed using different chelating agents to solubilize FeIII and CuII in a neutral aqueous solution. The first part of this work was devoted to the synthesis and characterization of organic complexes of FeIII and CuII in aqueous solution namely FeIII-GA and CuII-TA. In the second part, ibuprofen (IBP) and propranolol (PRO) were used as model molecules to study the activation of several oxidants by these organometallic complexes. A preliminary study of the complex/substrate mixture in the dark and at room temperature was performed and confirmed the absence of interaction between the substrate and the complexes. The effect of different factors, such as initial pH, oxygen, complex concentration, as well as substrate concentration, on the degradation of IBP and PRO was examined. The mineralization of IBP required more time than the degradation. The mechanistic aspect was also taken into account and shows the role of the oxidizing radicals involved in the modified Fenton-like process which would involve the •OH radical for both complexes whereas the combined effect of SO4•− and •OH radicals particularized the case of the PMS/complex. The application of these processes for the degradation of different pharmaceutical products has shown the superior catalytic capacity in comparison with other treatment processes.