Photocatalytic degradation of disulfine blue using titanium dioxide nanoparticles under ultraviolet light irradiation: A response surface methodology approach

Abstract

Disulfine blue (DSB) was photodegraded under ultraviolet (UV) light irradiation catalyzed by titanium dioxide (TiO2). To study this photodegradation, central composite design (CCD) under response surface methodology (RSM) was applied to design a systematic set of experiments. The pH was individually optimized and found to be 6.0. Variables such as initial dye concentration, photocatalyst dosage, and irradiation time were involved in the experiments while the dye photodegradation percentage was considered as response. The effects of variables on the response were studied and optimized. The optimum response (>90%) was obtained at condition 20 mg/L, 0.015 g and 35 min corresponding to DSB concentration, photocatalyst amount and irradiation time, respectively. The fact that the maximum DSB decomposition has been performed at neutral pH by using small amount of photocatalyst is an advantage of the procedure applied. From kinetics study of DSB photocatalytic degradation, the rate constant was found to be 0.0748 min−1. The Langmuir–Hinshelwood rate constant and adsorption constant were found to be 3.68 mg/min L and 0.00933 L/mg, respectively. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1657–1663, 2016