INVESTIGATION OF UV/TiO2-ZnO-Co PHOTOCATALITIC DEGRADATION OF AZO DYE (REACTIVE RED 120) BY RESPONSE SURFACE METHODOLOGY

Abstract

Advanced oxidation processes (AOPs) are the most attractive methods to degrade diferent organic pollutants. The AOPs have grown extensively because water quality control and regulations have become very strict in many countries. Optimizing the photocatalytic degradation of azo dye (Reactive Red 120) was our goal of research for applying the experimental design methodology. pH (X1), concentration of dye (X2) and TiO2-ZnO-Co nanoparticles volume (X3) in reactions were described mathematically as the function of parameters and were designed by using response surface methodology (RSM). Results were in agreement with empirical values and the sensitivity analysis showed above parameters as the most efficient variables in decolorization efficiency. Analysis of variance (ANOVA) revealed highly determination coefficient value (R2 = 0.9996 and adjusted-R2 = 0.999) and satisfactory prediction second-order regression model. The desirable quantities were obtained at the pH = 7, TiO2-ZnO-Co concentration = 0.1 g·L-1, and the initial Reactive Red 120 (RR 120) concentration = 16.4 mg·L-1. Finally, kinetics reaction of degradtion RR 120 was carried in the optimum conditions.

Keywords

• RR 120
• TiO2-ZnO-Co nanoparticles
• response surface modelling
• Photocatalytic degradation
• response surface modelling