Electrochemical treatment of acrylic dye-bearing textile wastewater: optimization of operating parameters

Abstract

The aim of the present study is to investigate the chemical oxygen demand (COD) and color removal efficiency and specific energy consumption during batch electrochemical treatment of synthetic textile wastewater having an initial COD of 3200 mg/L and containing yellow brown 2GL (basic orange 30) acrylic dye. Aluminum (Al) and stainless steel (SS) electrodes have been used as electrodes during the study. A Box–Behnken experimental design has been employed to evaluate the individual and interactive effects of four independent parameters namely: initial pH (pHo): 4–10, current density (j): 27.78–138.89 A/m2, NaCl concentration (w): 0–2 g/L and electrolysis time (t): 10–130 min on the COD and color removal efficiency and specific energy consumed. Pareto analysis of variance showed a high coefficient of determination (R2) value for COD (0.8815, 0.8995), color (0.9494, 0.8243), and specific energy consumption (0.9331, 0.8805) for Al and SS electrodes, respectively, between the experimental values and the predicted values by a second-order regression model. Maximum COD and color removal efficiencies and minimum specific energy consumed at optimum conditions using Al electrode were 46.87%, 98.61%, and 25.04 kWh/kg COD removed, respectively. Respective values for treatment with SS electrodes were 54.37%, 83.89%, and 30.19 kWh/kg COD removed, respectively.