Degradation of methyl orange in artificial wastewater through electrochemical oxidation using exfoliated graphite electrode

Exfoliated graphite (EG), with good electronic conductivity, was used as an anode material for the electrochemical degradation of methyl orange (MO), an artificial textile wastewater. Through the electrochemical degradation, 98.6% color removal and 58.5% chemical oxygen demand reduction was achieved at a pH of 2.0, a current density of 13 mA·cm−2, an electrolyte (NaCl) concentration of 0.1 mol·dm−3 and an electrolysis time of 20 min. The degradation is based on chemical adsorption and electro-oxidation. MO molecules are first adsorbed on the EG surface by hydrogen bonds between the -OH functional groups on EG and the MO molecules, which are then degraded by electrochemical oxidation. EG can therefore be regarded as an excellent material for the treatment of textile wastewater.