电化学氧化与还原联合处理偶氮染料废水的效能

Treatment Efficiency of Azo Dyes Wastewater by Combination Electrochemical Oxidation and Reduction

以Sb掺杂Ti/SnO2电极为阳极,铝板为阴极,设计了一种电化学氧化与电化学还原联合作用反应器.以浓度为100mg/L甲基橙模拟废水为研究对象,探究了电化学氧化与电化学还原联合作用的处理效能,并运用紫外-可见吸收光谱初步探究了甲基橙的降解机理.结果表明:在电流密度为20 mA/cm2、电解质浓度为0.10mol/L条件下,先电化学还原反应60 min再电化学氧化60 min联合处理甲基橙模拟废水,甲基橙的脱色率为94%,COD去除率为85%,处理能耗为0.21k Wh/g(COD).降解前后的紫外-可见吸收光谱的变化表明,电化学联合作用先使甲基橙的偶氮键断裂,然后破坏其苯环共轭体系,从而使甲基橙降解.

A new kind of electrochemical oxidation and electrochemical reduction combining reactor was de- signed with the Sb doped Ti/SnO2 electrode used as an anode and aluminum plate as a cathode. Concentration of 100mg/L methyl orange simulation wastewater for the study, the combining treatment efficiency of electrochemical oxidation and reduction was probed. Furthermore the degradation mechanism of methyl orange was studied prelimi- narily via UV-visible absorption spectrum. The results showed that under the condition of the current density of 20 mA/cm2 and electrolyte concentration of 0. 10 mol/L. When the methyl orange wastewater was first treated by coupling electrochemical reduction of 60 rain and then by electrochemical oxidation of 60min, the values of decolor- ization rate, COD removal rate and energy consumption reached 94%, ly. The changes of UV-Vis absorption spectrum for before and after d 85% and 0. 21 kWh/g（COD）, respective- egradation showed that the electrochemical combination first broke methyl orange azo bond then destroyed the benzene conjugated system, so that the methyl orange was degraded.