基于空气扩散阴极的过流式反应器产单线态氧降解水中亚甲基蓝

构建了钛基二氧化钌(Ti/RuO₂)阳极耦合空气扩散阴极(ADC)的电化学氧化体系,利用过流式反应器对亚甲基蓝(MB)进行氧化去除。结果表明:ADC阴极在200 mA电流下产生H₂O₂的稳定浓度达到45.33 mg/L,电流效率为65.10%。ADC-RuO₂体系对有机污染物的氧化具有选择性,几乎不能氧化苯甲酸钠,但对亚甲基蓝等染料具有较强的氧化作用。且该体系在叠氮化钠和2,5二甲基呋喃等存在时氧化能力受到显著抑制,证明其主要的活性氧化物为单线态氧(~1O₂)。在停留时间为2 min和电流为200 mA条件下,该体系对0.1 mmol/L MB的去除率达到99%,并且MB浓度降低90%时对应的能耗为0.25 kW·h/m3。

DEGRADATION OF METHYLENE BLUE IN WATER BY SINGLET OXYGEN GENERATED FROM FLOW-BY REACTOR BASED ON AIR DIFFUSION CATHODE

In this study, an electrochemical oxidation system consisting of Ti/RuO₂ anode and air diffusion cathode(ADC) was constructed, to oxidative remove methylene blue(MB) in a flow-by reactor. The results showed that the stable concentration of H₂O₂ produced by ADC reached 45.33 mg/L under the current of 200 mA, with a current efficiency of 65.10%. The ADC-RuO₂ system was selective for the oxidation of organic pollutants, since it barely oxidized sodium benzoate but showed a strong decolorizing effect on dyes such as methylene blue. In addition, the oxidizing ability was significantly inhibited in the presence of sodium azide and 2,5 dimethylfuran, suggesting the main active oxidant was singlet oxygen(~1O₂). At the residence time of 2 min and 200 mA, the removal efficiency of 0.1 mmol/L MB reached 99% in the system. Furthermore, the energy consumption for reducing the MB concentration by 90% was 0.25 kW·h/m3.