Comparative Removal of Rhodamine B from Aqueous Solution by Electro‐Fenton and Electro‐Fenton‐Like Processes

Abstract

Recently, electro‐Fenton (EF) process has received great attention in the field of wastewater treatment. Removal of rhodamine B (RhB) from aqueous solution has been investigated by EF and EF‐like process in graphite‐graphite EF system. Efficiencies of Fe0, Fe2+, Fe3+, Cu2+, and Mn2+ as Fenton and Fenton‐like catalysts for removing RhB from aqueous solution were compared. Effects of operating parameters such as solution pH, catalyst concentration, electrolysis time and applied voltage on dye removal were analyzed. It has been demonstrated that more than 90% dye removal was obtained after 180 min electrolysis at an optimal solution pH 3 for EF process and 2.5 for EF‐like process. Model predicted values for first order kinetics were very near to experimental values than that of pseudo second order kinetic model, suggesting that EF and EF like process follows first order kinetics. The rate of RhB removal at optimum catalysts concentrations follows the order of Fe0 > Mn2+ > Fe3+ > Fe2+ > Cu2+. In contrary to this, Fe3+ was found as the best catalyst for the RhB removal with a less optimal concentration of 5 mg/L. The present study demonstrated that EF and EF‐like processes are promising technologies for the treatment of dyes from aqueous solution.