Treatment of a Food Industry Dye, Brilliant Blue, at Low Concentration Using a New Photocatalytic Configuration

Abstract

Food coloring has become one of the main sources of water pollution. Brilliant blue (BB) is one of the dyes used in the food industry. Heterogeneous photocatalysis is increasingly used to decontaminate polluted water from food industries. The objective of this paper was to treat this pollution using a photoreactor at the laboratory (batch) and pilot scales. The photodegradation of the brilliant blue dye, chosen as a model of pollutant, was performed at room temperature in an aqueous solution of titanium dioxide supported on cellulosic paper in the presence of an external UV lamp. The surface morphology of this photoactive tissue was characterized by SEM and FTIR. The performances of two geometric configurations were examined (batch reactor and annular recirculation reactor) in accordance with degradation and pollutant mineralization. The performance of the photocatalytic system was optimized by a parametric study to improve the impact of the different parameters on the efficiency of the degradation process, namely the initial concentration of the pollutant, the TiO2 cycle, the pH of the solution with the recirculating reactor, and the flow rate. The results showed 98% degradation of brilliant blue at the laboratory scale and 93.3% and 75% at the pilot flow rates of 800 and 200 L·h−1, respectively. The supported semiconductor showed good photodegradation ability during BB decomposition, showing that photocatalysis is a promising technique for water purification.