Many sub-products of pulsed discharge,such as ultraviolet light,strong electric fields,shock waves and active species,are effective in treating wastewater.To improve the efficiency of the discharge plasma technology i...Many sub-products of pulsed discharge,such as ultraviolet light,strong electric fields,shock waves and active species,are effective in treating wastewater.To improve the efficiency of the discharge plasma technology in removing pollutants,adding TiO2 photo-catalyst to pulsed discharges could help.A negative-pulsed-discharge system,which has nozzle discharge electrodes with or without TiO2 coating,is used to degrade azo dye Acid OrangeⅡ,and the effects of several key conditions(maximum pulse voltage,pulse repetition frequency,initial mass concentration of Acid OrangeⅡinitial solution pH,treatment duration,the phase of discharge,and the existence of TiO2)on the degradation are experimentally investigated.The degradation of Acid OrangeⅡincreases with maximum pulse voltage,pulse repetition frequency,and treatment duration,and it is larger when putting the discharge electrode on the solution surface than in air or inside the solution,i.e.the discharge in gas phase is more effective than that in gas-liquid phase or liquid phase.The degradation decreases as the initial mass concentration of the solution increases.It also relates to pH and is higher at acidic conditions than at neutral or alkaline conditions.Compared to treatments without TiO2,the ones using the nozzle discharge electrode with TiO2 coated increase the degradation of Acid OrangeⅡby 5%.It is concluded that the proposed system with TiO2 added in can remove Acid OrangeⅡfrom wastewater effectively.展开更多
基金Project supported by National Natural Science Foundation of China(51207089)Shang-hai Maritime University(20120097).
文摘Many sub-products of pulsed discharge,such as ultraviolet light,strong electric fields,shock waves and active species,are effective in treating wastewater.To improve the efficiency of the discharge plasma technology in removing pollutants,adding TiO2 photo-catalyst to pulsed discharges could help.A negative-pulsed-discharge system,which has nozzle discharge electrodes with or without TiO2 coating,is used to degrade azo dye Acid OrangeⅡ,and the effects of several key conditions(maximum pulse voltage,pulse repetition frequency,initial mass concentration of Acid OrangeⅡinitial solution pH,treatment duration,the phase of discharge,and the existence of TiO2)on the degradation are experimentally investigated.The degradation of Acid OrangeⅡincreases with maximum pulse voltage,pulse repetition frequency,and treatment duration,and it is larger when putting the discharge electrode on the solution surface than in air or inside the solution,i.e.the discharge in gas phase is more effective than that in gas-liquid phase or liquid phase.The degradation decreases as the initial mass concentration of the solution increases.It also relates to pH and is higher at acidic conditions than at neutral or alkaline conditions.Compared to treatments without TiO2,the ones using the nozzle discharge electrode with TiO2 coated increase the degradation of Acid OrangeⅡby 5%.It is concluded that the proposed system with TiO2 added in can remove Acid OrangeⅡfrom wastewater effectively.
