针-水电极正直流高压放电对甲基橙染料废水的脱色

Study on decoloration of methyl orange dye wastewater by positive DC high voltage discharge using needle-water electrode

采用针-水电极反应器,研究正直流高压放电处理甲基橙染料废水的效果.考察了不同放电形式和实验参数下对甲基橙染料废水脱色效果的影响.实验结果表明,电晕放电在处理时间0～25 min脱色效果比击穿流光放电处理效果好,而在处理25 min后击穿流光放电脱色效果好于电晕放电.在电压18 kV、电流15 mA、处理初始质量浓度为40 mg/L的甲基橙溶液30 min时,脱色率达到98％.该反应符合一级动力学反应,反应速率常数为0.127 mg/（L·min）.经过放电处理,甲基橙的特征吸收峰（465 nm）强度逐渐减弱并基本消失,分子结构中的偶氮基团与苯环组成的共轭体系被破坏,甲基橙分子被有效降解.

The decoloration of methyl orange wastewater by positive DC high voltage discharge using needle-water electrode was investigated. The removal efficiency was studied for different discharge man- ners and experimental parameters. The results showed that the removal efficiency by corona discharge was better than the stream discharge in 0--25 min. However, the removal efficiency by stream discharge was better than corona discharge after 25 min. The removal efficiency was 98~ under the condition of applied voltage 18 kV, current 15 mA, initial concentration 40 mg/L with treatment for 30 min. The decoloration reaction followed first-order reaction kinetics, the reaction rate constant was 0. 127 mg/（L ~ min）. The in- tensity of methyl orange absorption peak （465 nm） gradually weakened and disappeared by discharge, the conjugated system composed of azo group and benzene in the molecular structure was destroyed, methyl orange molecules were degraded effectively.