Implementation of a venturi photocatalytic reactor: Optimization of photodecolorization of an industrial azo dye

Abstract

The photocatalytic decolorization of the textile azo dye C.I. Basic Red 46 was studied in a semi-pilot photocatalytic reactor combined with an emulsion venturi. The venturi has two principal roles, bring dissolved oxygen necessary for the photocatalytic reaction, and ensure a good homogenization, within its divergent, of the mixture dye solution-air-TiO2 particles. This study shows that this proposed photoreactor can be easily applied and extrapolated in photocatalysis reactions with a significant performance.The optimization of UV/TiO2 process in the photoreactor was carried out using the response surface methodology (RSM), based on the central composite design (CCD), to assess individual and interactive effects of the four main independent parameters (initial dye concentration, concentration of TiO2, flow rate (QL) and initial (pH) on the decolorization Efficiency Y (%) of (BR46)). Experimental results found from RSM was in good agreement with the model prediction (R2 = 0.96 and Adj-R2 = 0.92) and the presence of venturi has increased the discoloration rate of 20%. The optimization results showed that maximum decolorization efficiency was achieved at the optimum conditions: pH 8.68, TiO2 = 0.97 g/L, QL 1324 L h−1, [RB46] 5 mg L−1. Keywords: Photocatalysis, Photoreactor, Venturi, Response surface methodology (RSM), Basic Red 46, Central composite design (CCD)