Cu^(2+)/吡啶/H_2O_2对直接大红4BE的快速脱色研究

Rapid decolorization of direct red 4BE by Cu (Ⅱ) /pyridine/H_2O_2

为了明确影响Cu2+/吡啶/H2O2对模拟染料(DR4BE)废水脱色的主要因素,采用动力学分析、正交和Box-Behnken实验设计研究了不同溶液pH、Cu2+、吡啶、H2O2浓度及Cu2+、吡啶和H2O2组合对初始脱色速率常数和最终脱色率的影响.同时,采用自由基抑制、H2O2催化分解实验探索了Cu2+/吡啶/H2O2对染料的脱色机理.结果发现,Cu2+/吡啶/H2O2能有效使DR4BE快速脱色,脱色效率远高于Cu2+/H2O2;pH是影响初始脱色速率最重要的因素,吡啶、Cu2+及pH是影响最终脱色率最重要的因素;溶液pH在7.0左右时有利于该脱色过程的快速进行.Cu2+与吡啶的交互作用相对较强,吡啶、Cu2+与H2O2的交互作用相对较弱.羟基自由基氧化是Cu2+/吡啶/H2O2对染料DR4BE初始快速脱色的主要机理.研究结果还表明,Cu2+/吡啶/H2O2体系可用于中性条件下染料废水的快速脱色处理.

The decolorization of simulated wastewater containing the dye direct red 4BE（R4BE） by Cu （Ⅱ） /pyridine/H2O2 was studied. The solution pH,concentration of Cu （Ⅱ） ,pyridine and H2O2 and the effect of their combination on the decolorization process was studied by kinetic analysis, orthogonal and Box-Behnken methods. Experiments on hydroxyl radical inhibition and catalyzed H2O2 decomposition were conducted to investigate the decolorization mechanism of the dye,and the results indicate that the Cu （Ⅱ） /pyridine/H2O2 system can decolorize DR4BE at a much higher efficiency than the Cu （Ⅱ） /H2O2 system. The pH is the most important factor affecting the initial rate of decolorization,while the pyridine,copper and hydrogen peroxide concentrations are important factors that influence the final decolorization efficiency. A neutral pH is favorable for decolorization of DR4BE by Cu （Ⅱ） /pyridine/H2O2. Moreover,copper and pyridine showed a significant interactive effect,while Cu （Ⅱ） /H2O2 and pyridine/H2O2 showed slight interaction effects. Hydroxyl radical oxidation is the main mechanism in Cu （Ⅱ） /pyridine/H2O2 decolorization of dye DR4BE. This study further hints that the Cu （Ⅱ） /pyridine/H2O2 process provides an alternative method for rapid decolorization of dye wastewater under near-neutral conditions.