Study On The Treatment Of Phenol Wastewater By Two Phase Gliding Arc Discharge Plasma With Sodium Sulfate

In recent years,with the development of economy,the environmental problems are becoming more and more serious,especially the discharging of organic wastewater.Due to the characteristics of high organic matter content and low biodegradability of waste water,more of them are currently degraded using plasma technology.In plasma processing,Gliding arc discharge plasma technology is.widely used for the reason of its high processing efficiency,simple equipment,easy operation,and no secondary pollution.In this paper,phenol solution was usedas the research object to simulate the organic wastewater that was degraded by gliding arc discharge plasma technology.Study the effect of different discharge conditions on the treatment effect,by changing that applied voltage,carrier gas flow rate and initial concentration of phenol.The results show that the degradation rate of phenol solution increases with the increase of applied voltage.when the applied voltage exceeds 14 kV,the degradation rate of phenol does not change significantly and expected to be over 80%.Considering the economical choice of the best applied voltage is 14kV;the degradation rate of phenol solution decreases linearly with the carrier gas flow rate.When the the carrier gas flow rate must be controlled within 8～10 L/min that the rate of discharge is more than 85%,the degradation rate of phenol solution increases first and then decreases with the increasing of its initial concentration,but the absolute degradation rate keeps rising.When the degradation rate of phenol is greater than 80%,the initial concentration must be in the range of 200-350 mg/L.In order to further improve the degradation rate and make full use of the physical effects of gliding arc discharge,the persulfate oxidation technology and the sliding arc discharge plasma technology are combined to degrade organic wastewater that proposed in this paper.By observing the voltage-current waveform and emission spectrum during the discharge process,the liquid phase introduces the effect of sodium persulfate on the electrical and optical properties of the sliding arc discharge.The effects of the voltage,the flow rate of the carrier gas,the amount of sodium persulfate,and the initial concentration of phenol on the degradation rate were compared between a single gliding arc discharge system and a sodium persulfate-gliding arc discharge system.The experimental results show that the degradation rate of phenol is increased by 3.4%to 12.2%compared with single sliding arc discharge treatment under the same conditions,indicating that sodium persulfate and gas-liquid two phases gliding arc discharges show a significant synergistic effect during the phenol degradation process.When the applied voltage amplitude is not less than 14 kV,the carrier gas flow rate is not higher than 10 L/min,and the mass ratio of phenol to sodium persulfate/phenol is 250 to 350 mg/L and the range of 5.2 to 6.4,the phenol degradation rate of the gas-liquid two-phase sliding arc discharge can be maintained above 90%.The experimental results show that the gliding arc discharge plasma technology and persulfate oxidation technology combined technology can effectively improve the degradation efficiency,and make use of the physical effect of gliding arc discharge process prompted persulfate activated sulfate free radicals,and oxidation degradation of pollutants.The combined technology has high degradation efficiency,simple operation,low cost and no secondary pollution,which lays a theoretical foundation for the practical engineering application of organic wastewater degradation.