Removal of Reactive Black 5 from simulated textile effluents by an electrocoagulation process: optimization by response surface methodology

The textile industry creates one-fifth of the world's industrial water pollution, thus, the electrocoagulation (EC) process was proposed and investigated as an alternative eco-friendly treatment for water reuse. This study aimed to assess the removal efficiency of the Reactive Black 5 (RB5) from synthetic textile effluent by EC. Key operating parameters on EC process efficiency were optimized using response surface methodology (RSM). The main independent variables studied were the current density, EC time, concentration, and pH while the RB5 dye removal was studied as the dependent variable. The range of the studied parameters affecting the EC process was from 10 to 60 mA/cm(2), from 5 to 30 min, from 4 to 10 pH and from 10 to 40 ppm for current density, EC time, pH, and RB5 concentration; respectively. The optimal operating parameters turned out to be 5.5 pH, 47.5 mA/cm(2), 23.75 min, 17.5 ppm, and the predicted RB5 dye removal was 96.33%. The experimental dye removal with optimum operating conditions was in good agreement with the predicted removal efficiency. Therefore, the experiment results revealed the high potential of the EC process to effectively treat textile industry effluents and the RB5 dye removal was successfully optimized using RSM.