Application of Carbon Nanotubes Coated Electrodes and Immobilized TiO₂ for Dye Degradation in a Continuous Photocatalytic-Electro-Fenton Process

In this research, the decolorization of acid dyes in binary solutions via a continuous photocatalytic-electro-Fenton (PEF–TiO₂) process was studied using a modified graphite electrode with carbon nanotubes and immobilized TiO₂ with adequate stabilities. The effect of the operating parameters including current density, initial dye concentration, iron ion concentration, and time on the degradation process was studied applying response surface methodology (RSM) using NaCl and Na₂SO₄ as the supporting electrolytes. The investigation of kinetic parameters indicated that the dye decolorization had followed a pseudo-second order kinetic model. The color and chemical oxygen demand removal (%) and electrical energy consumption were chosen as responses to optimize the process. The experimental results greatly agreed with the predicted data, illustrating that the RSM can be effectively used for the optimization of the removal procedure. It was then concluded that PEF–TiO₂ is a promising method with high efficiencies and reasonable energy consumption for dye elimination from multicomponent effluents.