Electrocatalytic Degradation of Methyl Orange Dyeing Wastewater by a Rare Earth Modified DSA Electrode

Dye wastewater has become one of the challenges in the field of wastewater treatment due to its highly toxic, potentially carcinogenic, and poor biodegradability. Electrocatalytic oxidation technology is widely used in the field of wastewater treatment due to its specific advantages. A homemade rare earth modified dimensionally stable anode (DSA) and a stainless steel plate were used as anode and cathode for the electrocatalytic degradation of methyl orange (MO) dyeing wastewater, respectively. The influence of current density, pH value, reaction temperature, and initial concentration on the degradation effect of MO was investigated. Moreover, the degradation kinetics and intermediates during the process of electrocatalytic degradation of MO were further studied. The results showed that the electrocatalytic degradation of MO wastewater exhibited an excellent treatment efficiency under certain conditions. When the current density was 120 mA·cm−2, the pH value was 7, the temperature was 308 K, and the initial concentration of MO was 50 mg·L−1, the removal rate of MO reached 100% after 2 h of degradation. The degradation reaction of MO follows the pseudo-first-order reaction kinetics, with an apparent activation energy of 20.67 kJ·mol−1, which is much lower than the activation energy of conventional conditions.