Removal of Dyes from Waste Solutions by Anodic Oxidation on an Array of Horizontal Graphite Rods Anodes

Abstract

In this work, degradation of two dyes, methylene blue and methyl blue, by anodic oxidation in a new arranged electrochemical cell is investigated in the presence of Cl- ions. The cell consists of an array of graphite rods working as the anode placed horizontally between two horizontal stainless steel screens cathodes. The cell performance is tested in terms of the color removal efficiency, COD removal, electrical energy consumption, anode efficiency, and current efficiency. Parameters studied are initial dye concentration, NaCl concentration, applied current density, and initial pH of the electrolyte. A maximum color removal of 94% and 98% were achieved for methylene blue and methyl blue respectively after 30 min treatment time. The normalized space velocity in terms of the kinetic parameters is determined and a maximum value of 3.59 m3m-3 h-1 was obtained for methylene blue and 4.09 for methyl blue.