Industrial Wastewater Treatment Using Sono-Pulsed Electrochemical Oxidation Process: Optimization Through Response Surface Methodology

Abstract

Water is a valuable resource and its sustainability ensure the existence and the maintenance of any kind of life. Nowadays, there is a vast amount of wastewater produced as a result of growing human activity, industrialization, and urbanization. Industrial sectors are currently the largest users of fresh water and produce a significant amount of wastewater with various constituents. In this study, the mineralization of industrial wastewater using pulsed electrochemical oxidation (PEO) and a combination of sonolysis and pulsed electrochemical oxidation (S-PEO) process was investigated in terms of percentage removal of chemical oxygen demand (COD), color, phosphate, total dissolved solid (TDS) and biological oxygen demand (BOD) with power consumption. The influence of experimental parameters including initial pH, electrolysis time and current ampere 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 responses for the assisted S-PEO process the values of factors at optimal conditions were obtained as follows: pH=7, electrolysis time=40 min and current =0.5. In these circumstances, the model degree of desirability was equal to 0.909, and the best values for the maximum removal percentages of the responses for COD, color, phosphate, TDS, and BOD were 97.04%, 99.70%, 98.70%, 97.44%, and 95.49%, respectively. The minimum power consumption for S-PEO was also 0.60 ampere. 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 COD, color, phosphate, TDS and BOD 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 PEO and S-PEO process parameters. Generally, these results demonstrate the superior efficiency of the S-PEO its feasibility on removal of industrial wastewater pollutant.