Abstract
Direct electrochemical oxidation of aqueous organic pollutants using Boron doped diamond (BDD) electrode is usually inhibited at low concentration of the target organic pollutant. In this study, a multivariate statistical approach was used to optimize the direct electrochemical oxidation of low phenol concentration using on BDD anodes by employing response surface methodology (RSM) technique. A 2(4) factorial faced centered central composite design was employed for the experimental design from which the influences of operating parameters were assessed using analysis of variance. The efficiencies of removal of phenol, total organic carbon and chemical oxygen demand, the percentage of aromatic byproducts produced, current efficiency, and energy consumed were collectively taking into account in the RSM optimization. All the six responses fitted quadratic models (R-2 of 83.21-98.48%) with the relative contributions of the investigated parameters on the responses following the order: reaction time > pH > electrolyte > current density. The optimum operating condition yielded complete oxidation of phenol with improved average current efficiency of 19.89% and specific energy consumption of 329.52 kWh/kg-phenol.