Cu循环催化羟胺与氧气反应降解甲基橙

Degradation of Methyl Orange in the Oxygen-Dependent Oxidation of Hydroxylamine Undergoing Copper-Redox Catalyzing Reactions

为研究Cu/O_2/HA(HA为盐酸羟胺)体系的氧化能力,以MO(甲基橙)为目标物,对该体系生成·OH(羟基自由基)的过程及机理进行了探讨,并分别考察了HA投加量(以c计)、pH、Cu(Ⅱ)投加量(以c计)和O_2通量对MO降解的影响.结果表明:Cu能够有效催化HA与O_2的反应,生成大量H2O_2,并进一步生成·OH,有效降解MO.HA投加量越高,MO降解率越高,但过高的HA投加量在初始阶段会对MO的降解形成抑制,最佳HA投加量为3 mmol/L;受到HA质子化的影响,反应的最适pH约为5.5;由于Cu(OH)_2不利于催化HA与O_2的反应,最佳Cu(Ⅱ)投加量为20μmol/L;O_2通量对MO的降解影响较小,最佳O_2通量为0.15 L/min;Cu/O_2/HA体系降解MO的初始阶段符合一级动力学模型.研究显示,Cu/O_2/HA体系具有良好的氧化能力,能够有效降解水中的MO,最佳反应条件下MO降解率达86.5%.

In order to test the oxidizing ability of the Cu/O2/HA process,methyl orange（ MO） was used as the target pollutant to study the mechanism of the generation of hydroxyl radicals（ ·OH） in the Cu/O2/HA process. The effects of pH,dosage of hydroxylamine（ HA）,dosage of Cu（ Ⅱ）,and flow rate of O2 on the degradation of MO in the Cu/O2/HA process were investigated. The results showed that Cu could effectively catalyze the reaction between HA and O2 and generate H2O2,which could further decomposed into ·OH,thus effectively degrading MO. MO degradation increased with the increase of HA dosage,but a high dosage of HA could inhibit MO degradation in the initial phase. The optimum dosage of HA was 3 mmol/L. Moreover,under the influence of unprotonated HA,the optimal pH for MO degradation was about 5. 5. Since Cu（OH2was conducive for the catalytic reaction between O2 and HA,the optimal Cu（ II） dosage was 20 μmol/L. The O2 flow rate slightly influenced the efficiency of MO degradation in the Cu/O2/HA process,and the optimal O2 flow rate was 0. 15 L/min. The initial phase of MO degradation in the Cu/O2/HA process fit well with the first-order kinetic model. The experimental results showed that the Cu/O2/HA process had a high oxidation capability,MO was effectively degraded in the Cu/O2/HA process,and the MO degradation reached 86. 5% under the optimum conditions.