用气相沿面放电生成臭氧方式降解偶氮染料废水的影响因素分析

Factor Analysis of Ozone Generation by Gas-phase Surface Discharge for Degradation of Azo Dye Wastewater

为提高臭氧降解和脱色染料废水的效果,通过沿面放电臭氧生成-废水处理一体化反应器降解偶氮染料废水研究了供电电源类型、放电电压、放电反应器内注入的气体组分及流量、废水电导率、催化剂等因素对染料降解的影响。研究结果表明:同50Hz工频电源相比,在相同的输入功率下,高频电源降解偶氮染料效果更快;沿面放电反应器内注入的气体成分影响染料降解率,注入氧气时,甲基红降解率最高,注入氮气时,甲基红几乎没有降解;注入气体流量影响气相和液相臭氧浓度及染料废水的湍流度,进而影响甲基红的降解率;废水电导率对甲基红降解影响不大;二氧化钛添加量影响甲基红的降解,染料降解初期,适量的二氧化钛有利于甲基红的降解。

Ozone is one kind of effective oxidants for decolorization and degradation of dye wastewater. Effective degradation of azo dyes was realized by ozone generated from a surface discharge reactor which was located inside wastewater. The influential factors including power generator type, applied voltage, component and flow rate of gas injected into discharge reactor, conductivity of dye wastewater and catalyst were discussed. The experimental results reveal that methyl red { MR） dye is degraded faster under the same input power when discharge electrode is supplied with a high frequency generator rather than the common AC generator （50 Hz）. The component and the flow rate of gas injected into discharge reactor have a more remarkable effect on MR degradation than the conductivity of dye wastewater. The highest degradation rate of MR is obtained when oxygen is injected into the discharge reactor, and MR is hardly degraded when nitrogen is injected. The air flux in discharge reactor affects the ozone concentration in gas and liquid phases as well as the turbulence in wastewater, and thus affects the degradation of MR. TiO2 catalyst also has some effects on degradation rate of MR, and its enhanced effect is observed at the early degradation stage of MR.