改性SnO_(2)电极电催化降解煤化工废水

Electrocatalytic Degradation of Coal Chemical Wastewater with Modified SnO_(2) Electrode

针对煤化工废水生化处理后无法达到污水排放和回用标准等问题,研究采用电催化氧化法降解废水中氨氮和COD来实现废水的零排放。比较了改性SnO_(2)电极(ESIX-SnO_(2))与Ti/SnO_(2)电极电化学性能,并考察电流密度、初始pH、初始Cl-质量浓度对电催化降解废水中氨氮和COD的影响。结果表明,与传统的Ti/SnO_(2)电极相比,ESIXSnO_(2)电极晶粒尺寸变小、析氧电位(1.67 V)和加速寿命(112 h)显著提高。在优化工艺条件下,电解30 min后,ESIXSnO_(2)电极对NH_(4)^(+)-N和COD的去除率分别为100%和90%。在实际催化氧化过程中,ESIX-SnO_(2)电极表面产生更多具有强氧化性的羟基自由基,能够快速氧化氨氮和有机物,实现了污染物的快速无害化去除。

Aimed at problems such as the failure to meet the wastewater discharge and reuse standards after the biochemical treatment of coal chemical wastewater, the use of electrocatalytic oxidation to degrade ammonia nitrogen and COD in wastewater to achieve zero discharge of wastewater was studied. The electrochemical properties of modified SnO_(2) electrode(ESIX-SnO_(2)) and Ti/SnO_(2) electrode were compared, and the effects of current density, initial pH and initial Cl-content on the electrocatalytic degradation of ammonia nitrogen and COD in wastewater were investigated. The results showed that, compared with traditional Ti/SnO_(2) electrodes, the grain size of ESIX-SnO_(2) electrode became smaller, the oxygen evolution potential(1.67 V) and accelerated life(112 h) were significantly improved. Under optimized process conditions, after 30 minutes of electrolysis, the removal rates of NH_(4)^(+)-N and COD by ESIX-SnO_(2) electrode were 100% and 90%, respectively. In the actual catalytic oxidation process, the surface of the ESIX-SnO_(2) electrode generated more hydroxyl radicals with strong oxidization, which could rapidly oxidize ammonia nitrogen and organic matter,and realized the rapid and harmless removal of pollutants.