Keywords: 
• catalytic oxidation /
• ozonation /
• MnOx/mesoporous γ-Al2O3 /
• phenazone /
• mineralization /

Abstract: In order to explore in depth the effects of parameters，such as electric parameters (pulsed voltage，pulse frequency and pulse power)，gas parameters (gas varieties and gas bubbling rate) and solution parameters (initial pH value and conductivity value) etc.，in the hybrid gas-liquid pulsed discharge plasma system on organic compounds degradation，a multi-needle-to-plate hybrid gas-liquid pulsed discharge plasma system was established. In the research，the typical azo dye——Acid Orange 7 (AO7) was chosen as the target pollutant and an experimental system was set up to review the key factors for AO7 decoloration in the hybrid gas-liquid pulsed discharge plasma system. The obtained results reveal that the factors concerned with the input power of the pulsed power supply，such as pulse voltage peak value and pulse frequency，have distinct effect on the decoloration of AO7. With the increase of the pulse voltage peak value and the pulse frequency，the decoloration rate of AO7 and the pseudo-first-order kinetic constant of AO7 oxidation increased. Under the condition of 30 kV pulse voltage peak value，50 Hz pulse frequency，and 5 L/min air bubbling rate，the decoloration rate and the pseudo-first-order kinetic constant of the AO7 solution with 10 mg/L reached 92.7% and 3.50×10-2min，respectively. Furthermore，the effect of the initial solution condition (pH value) was also considered. The results prove that the acid solution condition is favorable for the dye decoloration and the corresponding values of decoloration rate and kinetic constant are higher.