Photodegradation Study of Toluidine Blue Dye in Aqueous Solution using Magnesium Oxide as a Photocatalyst

Abstract

The photocatalytic degradation of Toluidine Blue dye (TB) in aqueous solution was investigated under UV light in the presence of magnesium oxide (MgO) as a photocatalyst at different operating parameters. The operating conditions were photocatalyst dose, initial dye concentration and the pH of the solution. Increasing of photocatalyst dose from 10 to 70 mg enhanced the degradation rate of TB dye. However, the increasing of TB dye concentration from 2 to 8 mg/L negatively affected the degradation rate. It was found that the percent of dye removal reached the maximum value at high acidic medium. In dark condition, 15 % of dye was adsorbed by MgO. Furthermore, the kinetics involved in the degradation of TB dye was examined and the degradation was found to follow pseudo first order kinetic model.