Abstract:

The degradation of methylene blue by catalytic oxidation in Na₂WO₄-H₂O₂ system was discussed. The results showed that the degradation rate of methylene blue was near 100% after 40 min of reaction in Na₂WO₄-H₂O₂ system．The optimum conditions for 100mL methylene blue（10 mg/L）degradation were as follows：reaction temperature 60 ℃，sodium tungstate（0.01 mol/L）dosage 7.0 mL，30% H₂O₂ solution dosage 3.5mL. The degradation of methylene blue was effective in a wide range of pH value（1～14）. The UV-Vis spectroscopic analyses found that the characteristic absorption peaks originally in 664 nm，614 nm and 292 nm，244 nm disappeared，indicating that hazardous organic compounds were transformed into small molecules. Under these conditions，reaction rate constant for methylene blue degradation was 0.0879 min^－1，activation energy was 34.61 kJ/mol. The degradation of methylene blue in Na₂WO₄-H₂O₂ system accorded well with the first-order kinetics mode1.

摘要：

研究了钨酸钠-双氧水体系对亚甲基蓝模拟印染废水的催化氧化降解效果。结果表明，当0.01 mol/L的钨酸钠溶液的加入量为7.0 mL、30%的双氧水溶液的加入量为3.5 mL、反应温度60 ℃、反应40 min后，对100 mL浓度为10 mg/L的亚甲基蓝模拟废水的脱色率接近100%。反应在较宽的pH值范围（1～14），都有较好的去除效果。紫外可见光谱分析表明，原水样在664 nm、614 nm和292 nm、244 nm处的特征吸收波峰消失了，降解为小分子物质。在此条件下的亚甲基蓝降解速率常数为0.0879 min^－1，活化能较低，为34.61 kJ/mol。反应符合一级反应动力学模型。