Removal of Alizarin Red S from Wastewater: Optimizing the Process Parameters for Electrocoagulation Using Taguchi Method

Abstract

In this study, removal of Alizarin Red S (ARS) dye from aqueous solution using electrocoagulation (EC) process has been investigated. Taguchi method was applied to study the effects of parameters on removal of ARS. The process was carried out in a batch electrochemical cell with aluminum electrodes in a monopolar connection with 1 L of dye solution. The orthogonal array L9 experimental design was utilized to determine the effects of process parameters such as current intensity, initial dye concentration, and amount of NaCl as the electrolyte and inter-electrode distance. Three levels of each process parameter were chosen for optimization. Level range of parameters was chosen as for current intensity: 2–4 A, for initial dye concentration: 10–30 ppm, amount of NaCl: 5–7 ppm, and inter-electrode distance: 0.6–1.8 cm. The set of experiments were carried out at room temperature with initial pH of 7. A fixed time of 20 min was chosen for determination of removal efficiency. The optimum conditions were found as third level of current intensity (4 A), first level of initial dye concentration (10 ppm), third level of NaCl (7 ppm), and first level of inter-electrode distance (0.6 cm). The removal efficiency was found to be 89.27% at the optimal conditions. The optimized values were determined at which the maximum removal of ARS could be obtained. ANNOVA (delta ranking) is used to check the priority of the parameters and its effect on the removal of ARS.