Remediation of phenolic wastewater implementing nano zerovalent iron as a granular third electrode in an electrochemical reactor

Abstract

In this work, nanoparticles zerovalent iron (NFe°) and silty clay supported nano zerovalent iron (SC–NFe°) were utilized as a granular third electrode (3D) in the electrochemical technique. The two electrodes (2D) with aluminum plates as anode and cathode) and 3D electrochemical cells were utilized to remove aqueous phenol. For 2D electrochemical system, the optimal operating conditions were as follows: time = 0.5 h, pH = 4, current density = 50 mA/cm2, distance between electrodes plates = 4 cm, and phenol concentration = 500 mg/L, and the highest removal rate of phenol was 82%. The results demonstrated the considerable efficiency of the 3D electrochemical process (with NFe° and SC–NFe° as a granular third electrode) in treating phenolic wastewater. For 3D electrochemical process, the optimal operating conditions were as follows: pH = 2, operation time = 0.5 h, current density = 50 mA/cm2, electrode distance = 4 cm, and phenol concentration = 500 mg/L. The highest removal rates of phenol in 3D electrochemical technique with NFe° or SC–NFe° were 96.1 and 97.8%, respectively.