Optimization of Operating Parameters in the Removal of Synthetic Textile Dyestuff with the Electrocoagulation Process

Abstract

Electrocoagulation (EC) is one of the most effective electrochemical wastewater treatment techniques for removing color and organic pollutants from wastewater, and reducing sludge formation. In this study, the removal of Remazol Ultra Red RGB (reactive red 239) dye, which is used for commercial purposes, by the EC process was investigated. For this purpose, an electrochemical reactor was designed using monopolar parallel connected aluminum and iron electrodes. The effect of operational parameters such as the initial pH of the solution, current density, and electrolysis time were investigated to achieve higher color, Chemical Oxygen Demand (COD), and turbidity removal efficiency. The optimum conditions of the EC process were determined by evaluating the data obtained as a result of the experimental studies. It was observed that the removal efficiency increased with the increase of the electrolysis time and stabilized after 20 min. The optimum experiment conditions for the aluminum electrode were pH:3, current density of 50 A/m2, and conductivity of 250 µS/cm, for the iron electrode was pH: 5, current density of 75 A/m2, and conductivity of 500 µS/cm was found as. In all studies, the mixing speed was chosen as 250 rpm. As a result of this study, 95.49-99.94% color, 89.34-66.83% COD, and 92.18%-83.15% turbidity removal efficiencies were obtained with aluminum and iron electrodes under optimal conditions. Under optimum conditions, electrical energy consumption was calculated as 11.48 for Al, 6.60 kWh/m3 for Fe, and the energy consumption 0.56, 0.46 kg/m3. As a result of the experimental studies, high removal efficiencies were obtained in color, COD and turbidity removal with the EC process. As a result, it was concluded that EC treatment is an effective method for the purification of synthetic textile dyestuffs.