微波降解水中亚甲基蓝的研究

Degradation of Methyleneblue in Water by Microwave Radiation and Hydrogen Peroxide

对微波/过氧化氢联合降解水中亚甲基蓝进行了研究。考察了过氧化氢质量分数、pH、亚甲基蓝初始质量浓度等因素对亚甲基蓝降解效果的影响。结果表明，微波-过氧化氢降解亚甲蓝具有明显的协同作用。在实验条件下，采用微波-过氧化氢协同降解亚甲基蓝时，过氧化氢质量分数越高，亚甲基蓝降解率越高。溶液pH值对亚甲基蓝的降解率有明显的影响，当pH为6～7时，降解率有最小值。随着亚甲基蓝初始质量浓度升高，其降解率降低。微波-过氧化氢联合降解亚甲蓝的反应级数为一级，反应常数为0．1898 min^-1，反应活化能为2．76 kJ/mol。在亚甲基蓝初始质量浓度为50～70 mg/L、H2O2的质量分数1．0％、反应温度473 K、pH值为3或12、反应时间为7 min时，亚甲基蓝降解率为95．0％～96．0％。

The synergy effect of microwave/peroxide degradation of the methyleneblue in water is investigated in this study . The initial concentration of substrate ,pH ,and amount of hydrogen peroxide are examined to see their effect on the degradation performance ,respectively .The results show that microwave and hydrogen peroxide have obvious synergy on degradation of methylene blue .In this experiment ,the more concentrated of hydrogen peroxide ,the more degradation to the methyleneblue . The degradation is enhanced noticeably under appropriate pH ,the lowest degradation is noticed at the pH of 6~7 .With higher initial concentration of methylene blue ,the degradation rate is reduced .The degradation of methyleneblue is a first order reaction ,of which the reaction rate constant is 0 .189 8 min^-1 and the activation energy is 2 .76 kJ/mol .The degradation rate can be as high as 95 .0% ~ 96 .0% in the following conditions ：initial concentration 50 ~ 70 mg/L , the mass fraction of hydrogen peroxide 1 .0w t% ,473 K for 7 min ,pH=3 or 12 .