Degradation of paracetamol by advance oxidation processes using modified reticulated vitreous carbon electrodes with TiO_2 and CuO/TiO_2/Al_2O_3

摘要

The degradation of paracetamol in aqueous solutions in the presence of hydrogen peroxide was carried out by photochemistry, electrolysis and photoelectrolysis using modified 100 pores per inch reticulated vitreous carbon electrodes. The electrodes were coated with catalysts such as TiO_2 and CuO/TiO_2/Al_2O_3 by elec-trophoresis followed by heat treatment. The results of the electrolysis with bare reticulated vitreous carbon electrodes show that 90% paracetamol degradation occurs in 4 h at 1.3 V vs. SCE, forming intermediates such as benzoquinone and carboxylic acids followed by their complete mineralisation. When the electrolysis was carried out with the modified electrodes such as TiO_2/RVC, 90% degradation was achieved in 2 h while with CuO/TiO_2/Al_2O_3/RVC, 98% degradation took only 1 h. The degradation was also carried out in the presence of UV reaching 95% degradation with TiO_2/RVC/UV and 99% with CuO/TiO_2/Al_2O_3/RVC/UV in 1 h. The reactions were followed by spectroscopy UV-Vis, HPLC and total organic carbon analysis. These studies show that the degradation of paracetamol follows a pseudo-first order reaction kinetics.