ELIMINATION DU BLEU DE METHYLENE PAR DES PROCEDES D’OXYDATION AVANCEE

Abstract

In this thesis work, we studied the following advanced oxidation processes: US/Fenton, US/UV/TiO2, heated activated persulfate (PS) and bisulfite (BS) and its efficiency for the removal of methylene blue. The study of the influence of the operating parameters (pH, initial concentration of MB, PS and TiO2) on the kinetics and degradation efficiency of MB has shown that: the coupling of ultrasound to Fenton and heterogeneous photocatalysis processes increases the rate and speed of degradation, which has been confirmed by monitoring the evolution of H2O2, NO2 - , and NO3 - during the treatment. Degradation by the SO4 •- radical is favoured at medium pH and high oxidant concentrations (PS, BS). The activation energy of PS was found equal to 46 kJ by Arrhenius' law. The response surface helped us to extract the optimal conditions of the Fenton process (pH = 2.9, R = 23.6 and [Fe(II)] = 0.0015M).