3D electrochemical technique with biowaste nano zerovalent iron granular electrodes for cationic dyes removal from aqueous solution

Abstract In this study, biowaste nano zerovalent iron (NZFe) was synthesized by a simple procedure from banana peel extract and was utilized, for the first time, as granular third electrodes in the 3D electrochemical system for cationic dyes removal. The aim of this study is to detect the efficacy of the synthesized biowaste NZFe as a granular third electrode for cationic dyes removal. The physical and chemical properties of the synthesized NZFe were determined using scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared, and Brunauer–Emmett–Teller surface area analysis. An electrochemical cell with graphite as anode and stainless steel as cathode was used. A 3D electrochemical system with NZFe as granular third electrodes was found to be more efficient than a 2D electrochemical system for removing cationic dyes from an aqueous solution. The highest removal rates of methyl green and basic blue 41 under the optimum operating conditions (NZFe dose of 2 g/L, pH of 5, electrolysis time of 35 min, 0.3 g/L [Na 2 SO 4 ], current density of 50 mA/cm 2 , and dye concentration of 100 mg/L) were 98.8% and 97.1%, respectively. The potential mechanism of the removal of cationic dyes utilizing the 3D electrochemical system with the NZFe as granular third electrodes was proposed.