Optimizing operating parameters using experimental design in photocatalytic degradation of a model pollutant paracetamol by TiO2

Abstract

The main objective of this study was to demonstrate the efficiency and to optimize the operating conditions of photodegradation of paracetamol in the presence of suspended titanium dioxide catalyst in a photoreactor. An experimental design study was carried out using central composite design modelling. Optimization was applied to the tubular reactor under fixed photonic flux with radiation from two 24-watt UV-A lamps. The optimal values of the operating parameters were found to be pH of 7.288, TiO2 concentration of 0.9932 g·L–1 and paracetamol initial concentration of 15 mg·L–1. The paracetamol degradation rate approached 98.46% under optimal conditions. Modelling of the system led to a second-degree polynomial. Regression analysis gave an R2 value of 0.977 which meant good agreement between the experimental results and the predicted values. An interaction was demonstrated between the catalyst and the operating parameters (pH, CPara and CTiO2) as well as between the model pollutant concentration and the pH had an insignificant effect on the yield compared to that of the quantity of the catalyst and the initial pollutant concentration.