摘要
在尽可能地排除UV、传质及自由基吸收剂等影响的情况下,在 293.2~298.5K和pH3.2~13.0条件下,用Stopped-Flow光谱仪研究了O3在水中分解反应动力学.pH3.2~13.0条件下,O3分解相对于O3的反应级数为1级.在pH 10.1~10.3之间,OH(或pH对O3分解的影响可能有一个突变点.pH 10.1~10.3以下(含pH 10.1点),O3分解相对于OH(反应级数平均为0.13, 在pH 10.1~10.3以上(含pH 10.3点),O3分解相对于OH(反应级数为1.37.在pH 10.1~10. 3以下时,O3分解活化能为146.7kJ@mol(1.
The kinetics of ozone decomposition in water was investigated in temperatures range of 293.2~298.5K in aqueous solution and the pH values of 3.2~13.0(the pH values of aqueous solution was regulated by using H2SO4 and NaOH) by using the stopped-flow spectrometer, in which some effect factors of ozone decomposition were removed such as mass transfer and radical absorber in buffer solution. It was observed that below pH10.1 the rates of ozone decomposition in normal temperature are slow and the half-life of ozone in water at pH10.1 is about 600s, but at pH10.3 the rate of ozone decomposition is so fast that the half-life of ozone in water is only several seconds. As it is well known that UV can accelerate ozone decomposition, the experiments below pH10.1 was undertaken by intermittent scanning to reduce the influence of UV. The kinetics of ozone decompostion is first order with respect to ozone concentration in the pH range of 3.2~13.0. There might be a mutant point about OH- effect on ozone decomposition at pH 10.1~10. 3. In the pH range below 10.1, the reaction order with respect to OH- concentration is 0.13, and the activation energy is 146.7kJ穖ol-1. In the pH range above 10.3, the reaction order respect to OH- is 1.37.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2001年第5期500-504,共5页
Journal of Chemical Engineering of Chinese Universities
基金
广东省自然科学基金资助课题(990642)
