类Fenton反应对偶氮染料橙黄II的脱色研究

Decolorization of dye orange II solution by modified Fenton reaction

以橙黄Ⅱ染料溶液为研究对象，通过正交实验确定了Fe-NTA／H2O2构成的类Fenton反应中各影响因子的最佳操作条件为：[H2O2]=20mmol／L，[Fe-NTA]=2．5mmol／L．pH=3。同时考察了反应时间、溶液pH值、H2O2浓度、Fe-NTA浓度对脱色效率的影响。实验表明脱色反应在30min内基本完成，类Fenton试剂能在较宽的pH范围内保持较好的脱色效果，而且在pH=6时，类Fenton试剂比传统Fenton试剂的脱色效率提高约75％。增加双氧水浓度可以提高橙黄Ⅱ溶液脱色率，但超过20mmol／L后效果提高不明显。在0．5～2．5mmol／L的范围内，Fe—NTA浓度对脱色效果的影响不显著。

Decolorization of orange Ⅱ was carried out in water using hydrogen peroxide and soluble Fe（Ⅲ） chelates of nitrilotriacetic acid. The optimal operating conditions of decolorization efficiency were determined by orthogonal experiments as following ： [ H2O2 ] = 20 mmol/L, [ Fe-NTA ] = 2.5 mmol/L, and pH = 3. Furthermore the effects of reaction time, pH, hydrogen peroxide dosage and Fe-NTA concentration on decolorization efficacy were investigated. It showed that the decolorization reaction was nearly completed within 30 minutes. Over 80% decolorization efficiency was achieved in the wider range of pH when modified Fenton reagent was employed. Compared with classical Fenton reagent, the decolorization efficiency increased by about 75% at circumneutral pH of 6. The increase of hydrogen peroxide dosage would increase the decolorization efficacy, but the effect of hydrogen peroxide became insignificant when the concentration was higher than 20 mmol/L. The Fe-NTA concentration had little effect on the decolorization efficacy at the range of 0. 5 - 2.5 mmol/L.