Optimization and modeling of UV-TiO₂ mediated photocatalytic degradation of golden yellow dye through response surface methodology

Abstract

In this article, heterogeneous photocatalysis of golden yellow (GY) dye by Evonik p25 titanium dioxide (PTD) and UV radiations was optimized by using central composite design of response surface methodology. The GY dye photocatalysis was expressed as the function of amount of PTD loading (X₁), GY dye initial concentration (X₂), and UV irradiance intensity (X₃). The optimization of degradation conditions was done by measuring two different responses, that is, color removal (Y₁) and chemical oxygen demand removal (Y₂). The effect of X₁, X₂, and X₃ were studied in the range 0.5–1.5 g/L, 15–35 W/m², and 10–30 mg/L, respectively. The quadratic model was suggested for Y₁ and Y₂. The numerical optimization of results was done via Design Expert software. The predictive results obtained were verified by performing actual experiments. The photodegradation kinetics, total organic carbon disappearance, effect of inorganic salts, and H₂O₂ concentration on GY dye photodegradation were also studied.

Keywords:

• Central composite design
• Golden yellow dye
• Heterogeneous photocatalysis
• Optimization
• Response surface methodology
• Titanium dioxide