OXIDATION OF PARACETAMOL BY COMBINATION OF SONOCHEMISTRY AND ELECTROCHEMISTRY ON BORON-DOPED DIAMOND ELECTRODE

Résumé

In this study, sonochemistry (US) was combined with electrochemistry (EO) to improve the degradation of paracetamol on a boron-doped diamond electrode. Voltammetric techniques such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used for the electrochemical analyzes. The study of the electrochemical behavior of the boron-doped diamond electrode, in the presence of the redox couple ferri / potassium ferrocyanide, has made it possible to demonstrate its quasi-metallic character. In addition, this quasi-metallic character of the electrode is improved in the presence of ultrasound. The oxidation of paracetamol was carried out by three methods: sonochemistry, electrochemistry and sonoelectrochemistry (coupling sonochemistry and electrochemistry (US + EO)). The results obtained showed an oxidation rate of paracetamol of 18%; 73% and 89% respectively for sonochemistry, electrochemistry and sonoelectrochemistry after only 1.5 hours. Thus, combining sonochemistry with the preparative electrolysis of paracetamol makes it possible to increase its degradation rate by more than 25%, in the case of this work. The kinetic study was performed according to the pseudo first order model. The apparent rate constants determined are: 0.11 (for US); 0.95 (for EO) and 1.34 h^-1 (for US + EO). The combination of sonochemistry and electrochemistry increased the rate of degradation of the organic compound. Sonochemistry and electrochemistry act synergistically in the sonoelectrochemical mineralization of paracetamol, as evidenced by the calculated degree of synergy value S (S = 0.21> 0).