响应面法在催化湿式氧化降解异佛尔酮中的应用

Application of response surface method in the degradation of isophorone by catalytic wet air oxidation

以Ru/TiZrO2为催化剂,采用催化湿式氧化法降解异佛尔酮废水,选择反应温度、氧气分压、反应时间、催化剂用量、初始pH为影响因素,以TOC去除率为响应值,采用响应面法研究影响因素及其交互作用对响应值的影响,建立二次多项式回归方程模型,并采用后退回归法进行模型精简.结果表明,反应时间和反应温度及其交互作用对TOC去除率影响极显著(P≤0.01);反应时间的二次项对TOC去除率影响显著(P≤0.05).随着反应温度的升高和反应时间的延长,TOC去除率逐渐提高.最后对模型进行验证,实验值与预测值具有很好的一致性,说明模型具有可靠的预测性,将该模型应用到催化湿式氧化中合理可行.质谱和离子色谱检测到异佛尔酮的降解产物主要为有机酮与小分子羧酸,由此提出对反应机理和降解途径的假设.

Ru/TiZrO2 catalyst was applied in the degradation of isophorone by catalytic wet air oxidation. Reaction t dosage and initial pH were chosen as factors and TOC removal was fixed as response value. The response surface method was applied to analyze the effect of these factors and their interactions on the response value. The quadratic regression model was established and refined by backward regression method. The results showed that TOC removal was significantly affected （P≤0.01 ） by reaction time, temperature and their interactions, and affected （P≤0.05） by the square of reaction time. TOC removal rate increased with reaction temperature, and reaction time. Finally, the model was verified by three experiments. The experimental values and the predicted values had good agreement, indicating the model was reliable and can be applied in the CWAO. The degradation intermediates of isophorone by catalytic wet air oxidation were determined by GC-MS and ion chromatography, which demonstrated that the main degradation products were organic ketones and small molecule carboxylic acids. A hypothesis of degradation mechanism and pathway was proposed.