Enhanced Degradation of Reactive Black 5 from Aqueous Solution over TiO2 Nanoparticles under UV Light Irradiation: Optimization, Experimental & Theoretical Approaches

In this study, the elimination of dye from contaminated water was considered by the photocatalytic process with TiO2. The effects of operational parameters like TiO2 dosage, initial dye concentration, pH, contact time and temperature on the rate of dye decomposition are studied. TiO2 nanoparticles were characterized by XRD, FESEM, and FTIR. The Response Surface Methodology was carried out to investigate the composition effect of input independent factors and removal efficiency (one dependent output response). The F-value (315.9), P-value (2.2 × 10−16), multiple R2 (0.9858), adjusted R2 (0.9827), and lack of fit (0.494) show that the reduced second-order model is greatly significant for dye removal by TiO2 nanoparticles. The efficacy of the process at the optimum operating conditions, pH=11, TiO2 dose (0.7 g/l), reaction time (67.5 minutes), Temperature (40 ℃), and initial dye concentration (55 mg/l) was 86.6%. By using regression coefficients derived from the model and the Solver “Add-ins”, higher removal efficiency was accounted to be 90%. The results showed that the TiO2 nanoparticles under UV light irradiation are very proper for reducing the concentration of pollutants in textile wastewater effluent.