Study on photocatalytic degradation of nitrotoluene in wastewater by nano-TiO₂ photocatalyst

Photocatalytic degradation of nitrotoluene in the presence of titanium dioxide (TiO₂) was performed in a circulating photocatalytic reactor. The influences of the concentration of titania, the concentration of hydrogen peroxide and the pH on the removal rate of nitrotoluene in wastewater were studied in order to obtain the optimum operational condition. The results showed that, when the initial concentration of 2, 6-DNT and 4-MNT were respectively 100 mg/L and 60 mg/L, the 0.1 g/L of nanometer titania, the 0.1 ml/L of hydrogen peroxide, the pH was 3, and the reaction time was 2 h, the removal rate of 2, 6-DNT and 4-MNT were 58.8% and 68.6% respectively. The reaction rate was found to obey pseudo first-order kinetics, when the concentration of nitrotoluene was low.