Investigation of Electrochemical Degradation of Basic Red 13 Dye in Aqueous Solutions Based on Cod Removal: Numerical Optimization Approach

Abstract

The aim of this study was to remove Basic Red 13 dye by electrochemical oxidation with Ti/Pt anodes and to numerically optimize the operating conditions such as current density (5-20 mA/cm(2)), flow rate (10-50 mL/min), initial pH (2-9) and supporting electrolyte concentration (10-100 mM) by using response surface methodology. Chemical oxygen demand analysis which was chosen as a response was performed according to closed reflux colorimetric method. Also, the effluent chloride levels were analyzed with the argentometric method. Momentary temperature, pH and electrical conductivity readings were taken with a multimeter. Although a number of possible system conditions were obtained with numerical optimization, the system operating conditions with the lowest energy consumption are considered to be optimal. From the quadratic model formed from central composite design in response surface methodology with numerical analysis, the optimum conditions were determined to be 4.38 for initial pH, 19.53 mA/cm(2) for current density, 40.78 mL/min for flow rate and 85.57 mM for supporting electrolyte concentration. At these optimum points, chemical oxygen demand removal efficiency was calculated as 99.98% and energy consumption values of the system were calculated as 7.91 kW h/m(3) and 0.98 kW h/kgCOD. Under these conditions when an industrial system is operated, the chemical oxygen demand removal yield will be 99.98% and the approximate cost of the system will be $1.25 to treat 1 ton of wastewater.