Contribution of photocatalysis for the elimination of Methyl Orange (MO) in aqueous medium using TiO2 catalyst, optimization of the parameters and kinetics modeling

Abstract

The photo degradation of methyl orange (MO) in water onto TiO2 under UV irradiation is investigated. The parameters (MO concentration, catalyst dose, time, flux intensity and pH) influencing the degradation kinetics are studied. The equilibrium adsorption time of MO in the presence of TiO2 is reached after 50 min of contact. Addition of H2O2 and NaCl at concentrations ranging from 100 to 500 ppm shows that the percentage of the photo degradation decreases with increasing the H2O2 concentration. The best results are obtained for a concentration of 100 mg/L, while NaCl has a negative effect on the MO photo degradation. The photocatalytic degradation rate was favored at high MO concentrations in agreement with the Langmuir–Hinshelwood (L-H) model. The constants kr and K for the MO photo degradation are found to be 0.048 mg L/min and 16.246 L/mg, respectively.