蜂窝陶瓷催化臭氧化降解水中微量硝基苯的动力学研究 |
摘要点击 3460 全文点击 1780 投稿时间:2006-01-16 修订日期:2006-03-02 |
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中文关键词 蜂窝陶瓷 催化 臭氧化 硝基苯 动力学 速率常数 温度 pH |
英文关键词 ceramic honeycomb catalyzed ozonation nitrobenzene kinetics rate constants temperature pH |
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中文摘要 |
实验表明单独臭氧氧化和臭氧/蜂窝陶瓷氧化在温度20℃、初始pH值6.87条件下对硝基苯的降解均遵循一级反应动力学模型,该条件下单独臭氧氧化和臭氧/蜂窝陶瓷氧化工艺对硝基苯的降解主要来源于高活性羟基自由基的氧化作用,同时证明了不同体系温度(10~40℃)和溶液初始pH值(3.00~10.96)下硝基苯的降解同样符合一级反应动力学.2种工艺对硝基苯的降解反应速率都随着温度的升高而增加,单独臭氧氧化的反应速率常数由0.37×10-3 s-1升高到1.49×10-3 s-1,臭氧/蜂窝陶瓷氧化的反应速率常数由0.56×10-3 s-1升高到2.46×10-3 s-1,温度越高反应速率提高的幅度却越小.随着pH的升高,单独臭氧氧化对硝基苯降解的反应速率常数从0.15×10-3 s-1增加到2.69×10-3 s-1,在pH值3.00~9.23范围内,臭氧/蜂窝陶瓷氧化工艺反应速率常数从0.17×10-3 s-1增加到1.90×10-3 s-1,在pH为10.96时反应速率常数下降到1.64×10-3 s-1. |
英文摘要 |
The experiment indicated that ozonation alone and ceramic honeycomb-catalyzed ozonation of trace nitrobenzene in aqueous solution followed the first-order kinetic model at the reaction temperature of 20℃ and the initial pH of 6.87. Under the conditions of this experiment, ozonation alone and ceramic honeycomb-catalyzed ozonation for degradation of nitrobenzene were primarily oxidized by highly active hydroxyl radicals. At the same time, the experimental results demonstrated that the degradations were similarly the first-order reactions depending on different temperatures (10~40℃) and different pH (3.00~10.96). The rate constants of degradation of nitrobenzene in the two different processes mentioned above were found to increase with increasing of temperature. The rate constant of ozonation alone appeared to be increased from 0.37×10-3 s-1 to 1.49×10-3 s-1, respectively, increasing from 0.56×10-3 s-1 to 2.46×10-3 s-1 in the process of ceramic honeycomb-catalyzed ozonation. The higher the temperature of system, the less extent of the enhanced degradation rate. With the increase of pH, the rate constants of ozonation alone increased from 0.15×10-3 s-1 to 2.69×10-3 s-1, and increased from 0.17×10-3 s-1 to 1.90×10-3 s-1 in the process of ceramic honeycomb-catalyzed ozonation as pH increased from 3.00 to 9.23, but it decreased to 1.64×10-3 s-1 at pH 10.96. |