【作者】 沈慧芳；

【导师】 陈焕钦；

【作者基本信息】 华南理工大学 ， 化学工程， 2002， 博士

【摘要】 本论文研究了溶解臭氧与间甲酚、对硝基苯酚、对硝基苯胺等有机物的反应动力学，异丙醇单独臭氧化以及O₃／H₂O₂复合氧化的动力学。在此基础上研究了臭氧化学吸收传质过程，并建立了带有一级臭氧自分解反应和一个平行二级臭氧化反应的臭氧吸收过程的增强因子理论预测模型，模拟了吸收过程中臭氧和有机物浓度的变化，并与实验值进行了比较。为了提高臭氧的利用效率，还研究了促传剂对臭氧降解水中对硝基酚的影响，筛选出了两种效果较好的促传剂，并初步探讨了促传剂的作用机理。 在T=298K，pH=2.1～7范围内，采用先进的停流光谱仪测定了臭氧水溶液和间甲酚、对硝基苯酚、对硝基苯胺水溶液的臭氧化反应速率常数和反应级数。测定结果表明：溶解臭氧与上述几种有机物的臭氧化反应总反应级数为二级，对臭氧浓度和有机物浓度分别为一级。降解每摩尔的间甲酚、对硝基苯酚和对硝基苯胺分别需要3摩尔、3摩尔和4摩尔臭氧。在同样的实验条件下，对硝基苯胺的臭氧化反应速率最快，间甲酚的臭氧化反应速率最慢，臭氧化反应速率随反应混合液pH值的增加而显著增大。本文还对芳香族化合物的降解机理作了初步的探讨。 实验研究了异丙醇水溶液与单一氧化剂H₂O₂，O₃以及复合氧化剂O₃／H₂O₂的氧化反应动力学。实验发现，异丙醇不能被H₂O₂单独氧化。在酸性和中性条件下，臭氧化反应是臭氧分子直接攻击异丙醇的反应占主导，反应总级数相对于O₃、异丙醇和H₂O₂浓度分别为1级、1级和0级；在碱性条件下，异丙醇在O₃／H₂O₂作用下较容易被氧化，复合氧化反应主要受生成羟基自由基及随后的自由基反应控制，反应相对于O₃、H₂O₂浓度分别为1级，与异丙醇浓度无关。 在T=298K条件下在鼓泡塔中分别进行了臭氧在水中、在对硝基苯酚和对硝基苯胺溶液中吸收的传质实验，测定了臭氧在鼓泡塔中的液相体积传质系数，研究了溶液的pH值、气速等因素对有机物降解速率的影响。在鼓泡塔中在酸性条件下对硝基苯酚和对硝基苯胺的降解速率随溶液pH值的增加而显著增加。然而，在碱性溶液中，有机物的降解速率随pH值增加很少，这是因为受到从气相更多还原

【Abstract】 This research investigated the reaction kinetics of m-cresol, p-nitrophenol and p-nitroaniline by ozone in aqueous solution, and the kinetics of ozonation and peroxone oxidation of 2-propanol in aqueous solution. On the basis of the kinetic information, mass transport of gaseous ozone accompanied by decomposition and ozonation reactions in bubble column were investigated. The expression of the enhancement factor in ozone absorption with a first order ozone self-decomposition and a parallel second order ozonation reaction was derived. Simulations were performed of the ozone concentration and the compound concentrations during an absorption experiment, and the results compared with the measured data. In order to improve the ozone’s utilization ratio, the effect of additives on the absorption rate of ozone in water and the ozonation rate of p-nitrophenol solution was also investigated. The nonyl acid and heptanoic acid were found more effective in enhancing mass transfer of ozone and degradation of p- nitrophenol. The mechanism of the mass transfer enhancement by these additives was discussed briefly.A stopped-flow spectrophotometer systems was used to study the reaction rates and orders of the ozonations between dissolved ozone and m-cresol, p-nitrophenol and p-nitroaniline in aqueous solutions of pH values varying from 2.1 to 7 at 298K. The overall ozonation reactions of m-cresol, p-nitrophenol and p-nitroaniline were second order with first order in each reactant. The stoichiometric determination indicated that three, three and four moles of ozone were required for conversion of each mole of m-cresol, p-nitrophenol and p-nitroaniline respectively. Under the same experimental condition, the ozonation rate of p-nitroaniline was the fastest and that of m-cresol was the slowest. At a given temperature of 298K, the overall ozonation rate of m-cresol, p-nitrophenol and p-nitroaniline increased rapidly with the solution pH in the range of 2.1 to 7 investigated. The destruction mechanism of aromatic compound was discussed briefly.Oxidation kinetics and degradation of 2-propanol by oxidants such as H₂O₂, O₃,更多还原