Degradation of methyl orange by pulsed corona discharge process in water

Properties of methyl orange (MO) degradation and their dependence on experimental parameters such as electrical polarity, pulse frequency, the material, and thickness of the discharge electrode, as well as electrode gap distance were investigated in a laboratory scale pulsed corona discharge system. The MO degradation and H2O2 generation were significantly enhanced by positive polarity than negative polarity because of the numerous micro-discharges that were generated by the space charge effect induced by positive polarity. The increase of pulse frequency reduced the MO degradation even though it enhanced the number of streamers produced. An electrode material having low electrical and thermal conductivities resulted in more MO degradation. The smaller the curvature radius of the discharge electrode, the more efficient the MO degradation was. The number of electrode needles and the electrode gap distance also affected MO degradation during the discharge process.