硫酸根自由基对甲基橙的处理效果及机理

Effect and mechanism of sulfate radical on methyl orange treatment

以甲基橙为目标物,研究基于硫酸根自由基的高级氧化技术对甲基橙的降解效果,同时分析pH及各类阴离子对甲基橙降解效果的影响。结果表明,n(过硫酸盐)∶n(甲基橙)为12、反应120 min后,甲基橙去除率达到51%。加入亚铁能极大加速甲基橙的去除率,n(甲基橙)∶n(Fe^2+)∶n(S2O8^2-)为1∶4∶12时,反应120 min后甲基橙去除率比单独过硫酸盐体系提高26%,前5 min甲基橙去除率即可达到42%。pH对Fe^2+/S2O8^2-体系或单独S2O8^2-体系降解甲基橙的影响较小。溶液中的NO3^-对Fe^2+/S2O8^2-体系降解甲基橙基本无影响。Cl^-、H2PO4^-、CO32^-或HCO3-对Fe^2+/S2O8^2-体系降解甲基橙均有一定程度的抑制作用,且整体呈现抑制作用随阴离子浓度升高而增大的趋势。

The degradation of methyl orange by advanced oxidation technology based on sulfate radical is studied,and the effects of pH and anions on the degradation of methyl orange are analyzed.The results show that the removal rate of methyl orange reaches 51%after 120 min when n(persulphate)∶n(methyl orange)is 12.The addition of Fe2+can greatly accelerate the removal rate of methyl orange.When n(methyl orange)∶n(Fe^2+)∶n(persulphate)is 1∶4∶12,the removal rate of methyl orange after 120 min is 26%,higher than that of single persulfate system.The removal rate of methyl orange is 42%after 5 min.The pH has little effect on the degradation of methyl orange in Fe2+/S2O8^2-system or single S2O8^2-system.NO3-has no effect on the degradation of methyl orange in Fe2+/S2O8^2-system.Cl^-,H2PO4^-,CO3^2-or HCO3^-inhibite the degradation of methyl orange in Fe^2+/S2O82^-system to some extent.The inhibitory effect increases withthe increase of the concentration of anion.