Wastewater treatment using sono-electrocoagulation process: optimization through response surface methodology

The hybrid treatment processes are one of the hot topics in wastewater and industrial effluent treatment, especially in the highly polluted wastewater can be treated effectively using the combined processes. The present study is to treat the wastewater using a hybrid sono-electrocoagulation process (SEC), and the effects of operating parameters such as current density (0.3 to 1 A/dm(2)), initial effluent pH (4 to 10), electrolyte concentration (1 to 6 g/L) and inter-electrode distance (1 to 3 cm) on % chemical oxygen demand (COD) removal, % color removal, and power consumption were studied. The operating parameters used for hybrid SEC for the treatment of wastewater were optimized using response surface methodology (RSM) based on central composite design (CCD). The quadratic regression models with estimated coefficients were developed for the % removal of COD, color, and power consumption. It was observed that the model predictions matched with experimental values with an R-2 for % COD removal, % color removal, and power consumption. The central composite design was selected in this study because of its efficiency concerning the number of runs required for fitting a second-order response surface model. The maximum removal of COD-97.50% and color-100% was observed with the minimum power consumption-0.55 kWh/m(3) for the treatment of wastewater using the hybrid SEC process.