Development Of Sono-Electrochemical Oxidation Process For Domestic Wastewater Treatment: Optimization Through Response Surface Methodology

Abstract

In this study, the elimination of organic compounds in wastewater using electrooxidation (EO) and a combination of electrochemical oxidation (EO) and ultrasonic (US) was investigated in terms of percentage removal of COD, color and turbidity with power consumption. The influence of experimental parameters including initial pH, electrolysis time, current ampere and NaCl/ CaCl2 concentration has studied to find out the optimum conditions leading to maximum percentage removal efficiency. The response surface methodology (RSM) based on Central Composite Design (CCD) was used to plan the experimental runs and optimization of results. According to the study, the optimum values of COD, Color and turbidity with power Consumption for US/EO were 99.70 %, 99.79 % and 99.28 % with 0.003 kWhr/m3 using CaCl2. These results were obtained at optimal conditions of pH 5.85, electrolysis time 47.15 minutes, current 0.57 Ampere and electrolytic concentration 1.42 g/L using aluminum as electrode. The significance of independent variables and their interactions were tested by means of the analysis of variance (ANOVA) with 95% confidence limits. Quadratic regression equation was suggested as a good model for prediction of chemical oxygen demand (COD), color and turbidity removal efficiency with power consumption. A good agreement between the model prediction and experimental results confirms the soundness of the developed model, which indicates that CCD could be effectively used to optimize the EO and US/EO parameters. Therefore, the combination of EO and US based AOPs has been proved to be efficient treatment techniques for removal of pollutant from domestic wastewater