Electrochemical oxidation of methyl blue dye by stainless steel tubes bundle anode

Abstract

Methyl blue dye was successfully electrochemically oxidised in a flow-through batch circulation process using a stainless-steel tube bundle anode. The experimental design and process optimisation were conducted according to the response surface Methodology with Rotatable Central Composite Design method. The controlled variables in this study were the solution flow rate, applied current, electrolyte concentration, and time. A quadratic mathematical model expressing the removal percentage as a function of the operating variables and their interactions was constructed from the experimental data. The accuracy of the model was confirmed using residual plots and an R2 value of 0.8526. Solution flow rate was found to promote the removal percentage up to 1.5 l/min, the applied current promoted the removal efficiency significantly up to 400 mA, the electrolyte concentration had a positive effect up to 2 M, and the removal efficiency increases generally with time, reaching the equilibrium removal percentage at 67.121 min. The optimum conditions for the target with the highest removal percentage of 91.333% were found to be 1.5 l/min solution flow rate, 400 mA applied current, 2 M electrolyte solution, and 67.121 min.