Photoelectro-Fenton combined with photocatalytic process for degradation of an azo dye using supported TiO 2 nanoparticles and carbon nanotube cathode: Neural network modeling

Abstract

In this work, treatment of an azo dye solution containing C.I. Basic Red 46 (BR46) by photoelectro-Fenton (PEF) combined with photocatalytic process was studied. Carbon nanotube–polytetrafluoroethylene (CNT–PTFE) electrode was used as cathode. The investigated photocatalyst was TiO 2 nanoparticles (Degussa P25) having 80% anatase and 20% rutile, specific surface area (BET) 50 m 2/g, and particle size 21 nm immobilized on glass plates. A comparison of electro-Fenton (EF), UV/TiO 2, PEF and PEF/TiO 2 processes for decolorization of BR46 solution was performed. Results showed that color removal follows the decreasing order: PEF/TiO 2 > PEF > EF > UV/TiO 2. The influence of the basic operational parameters such as initial pH of the solution, initial dye concentration, the size of anode, applied current, kind of ultraviolet (UV) light and initial Fe 3+ concentration on the degradation efficiency of BR46 was studied. The mineralization of the dye was investigated by total organic carbon (TOC) measurements that showed 98.8% mineralization of 20 mg/l dye at 6 h using PEF/TiO 2 process. An artificial neural network (ANN) model was developed to predict the decolorization of BR46 solution. The findings indicated that artificial neural network provided reasonable predictive performance ( R 2 = 0.986).