Electrochemical removal of acid red 18 dye from synthetic wastewater using a three-dimensional electrochemical reactor

Abstract

Electro-oxidation degradation of acid red18 (AR18) dye from synthetic wastewater was investigated using a three-dimensional (3D) electrochemical reactor with granular activated carbon (GAC) as a particle electrode. The effect of operating parameters such as pH, current density, particle electrode dose, dye concentration and electrolysis time was studied and the optimization was performed using Taguchi fractional factorial design. The results showed that maximum removal of AR18 (96.5%) and COD (84.8%) were obtained under pH of 3, current density of 20 mA/cm2, initial concentration of dye of 100 mg/L, GAC dose of 250 mg/L and time of 45 min. High R2 and P value < 0.05 showed the excellent fitting of the selected model with experimental data. In addition, the experimental results showed that current density was the most important factor in the removal of the AR18 and COD. The result of comparative tests showed higher electrocatalytic activity, higher H2O2 production and lower energy consumption of 3D electrochemical reactor compared to the electrolysis process alone. The reusability and stability tests demonstrated that GAC, as a particle electrode, has a high potential for catalytic degradation of AR18 from aqueous solution at six consecutive runs. Finally, the 3D electrochemical process can be considered as a good alternative to treat wastewater containing AR18 dye.