Decomposition of Phenol in Water by Gas Phase Pulse Discharge Plasma

This paper introduced a pulse discharge reactor with a novel electrode configuration for decomposition of phenol in water. A tungsten wire in the middle of the porous ceramic tube and a stainless steel mesh outside the ceramic tube attached to the inner wall of the reactor vessel were constructed as discharge electrode and ground electrode, respectively. The porous ceramic tube made gas phase and liquid phase separated. Oxygen, as the gas phase, was bubbled into phenol solution through the porous ceramic tube. The radicals, such as O₃, O^-, middotO, generated by pulse discharge in the oxygen atmosphere, dissolved in the solution through the pores of the tube and phenol can be degraded by these radicals. The effects of discharge energy, gas bubbling rate, solution conductivity and solution pH on the decomposition efficiency of phenol were investigated. The results showed that increased discharge energy could enhance the decomposition efficiency; the gas bubbling rate and solution conductivity had little effects on the decomposition efficiency of phenol, indicating that the new pulse discharge reactor had good feasibility for the wastewater treatment in a large range of conductivity; the discharge electrode located in oxygen atmosphere could prevent the erosion of the electrode, which was in favor of the industrialization of pulse discharge for treating organic contaminant.