Photocatalytic degradation of n-propanol wastewater by TiO2 combined with Fenton reactions

Photocatalytic degradation by ultraviolet (UV)/TiO 2 combined with Fenton reagent was employed in treating high concentration n-propanol solution. The influence of the TiO 2 dosage, the concentration of ferrous ion, the integral H 2 O 2 dosage and the optimizing H 2 O 2 adding program were investigated by a series of batch experiments. The increasing injection of the hydrogen peroxide during the reaction will make the reaction rate constant (k 1 ) 6.9% higher than the average injection when the integral H 2 O 2 dosage is fixed. The optimized parameters of the combined process can be listed as follow: [Fe 2+ ] was 0.30 g/L, [TiO 2 ] was 0.08 g/L, and average [H 2 O 2 ]b was 3.85 g/L (which was divided into six different parts, and the increasing gradient was 5%). After 6 h degradation under the ultraviolet (UV) photocatalytic irradiation, more than 88% removal of n-propanol was observed. When the wastewater is treated with the combined process, the degradation of n-propanol can be taken as the pseudo-first order reaction. Based on the experimental data, a semi-empirical model for estimating the reaction rate constant k 1 in cylindrical reactor was built, which will help to investigate the effect of system parameters and support further engineering design.