脉冲电化学氧化降解亚甲基蓝

Pulse-electrochemical oxidation for methylene blue

为改善传统电化学氧化的缺陷,将脉冲式供电引入到电化学氧化中,利用Ti/Pb O_2-PVDF电极,对亚甲基蓝(MB)模拟染料废水进行电化学氧化降解处理,分析初始浓度、脉冲电压、脉冲频率、占空比和Na Cl浓度等因素对降解效果的影响.结果表明,当MB初始浓度为100mg/L,脉冲电压为5.5V,脉冲频率为1500Hz,占空比为50%,Na Cl浓度为0.01mol/L时,降解效果最好.在相同条件下,比较脉冲与直流两种供电模式下的电化学氧化效果.结果表明脉冲模式下,90min内MB脱色率、COD去除率及电流效率分别为100%、94.5%和60.1%,均高于直流模式;脉冲模式下能耗为0.013k Wh/g COD,远小于直流模式的0.107k Wh/g COD.上述结果表明脉冲供电模式相比于直流供电模式具有明显优势.

In order to overcome the defects for the conventional electrochemical oxidation process, the pulsed power supply was introduced into electrochemical oxidation process with MB aqueous solution as simulated dye wastewater using the Ti/Pb O_2-PVDF electrode. The effects of five factors were analyzed, including initial concentration, pulse voltage, pulse frequency, duty ratio and Na Cl concentration, on the degradation efficiency. The optimized parameters obtained were listed as, initial concentration of MB 100 mg/L, the pulse voltage 5.5 V, the pulse frequency 1500 Hz, the duty cycle 50% and the Na Cl concentration 0.01 mol/L. Under this condition, the effect of electrochemical oxidation in the pulse and DC power supply mode were compared. The results showed that for the pulse mode, the MB decolorization rate, COD removal rate and current efficiency in 90 min were 100%, 94.5% and 60.1%, respectively, which were higher than that in the DC mode. The energy consumption for the pulse mode was 0.013 k Wh/g COD, which was far less than 0.107 k Wh/g COD for the DC mode. The results showed that compared to the DC power supply mode, the pulse mode had obvious advantages.