臭氧降解苯乙酮的动力学及机制

Kinetics and Mechanism of Ozonation of Acetophenone

研究臭氧化降解苯乙酮效率,利用相对法求算了苯乙酮与臭氧及羟基自由基的反应速率常数。结果表明,臭氧化处理能有效降解苯乙酮,苯乙酮与臭氧的反应速率常数KO3-ACP为0.171 L.mol-1.s-1,与羟基自由基的反应速率常数KOH-ACP为7.07×109 L.mol-1.s-1。不同pH的试验表明,利用测得的两个反应速率常数能很好地预测苯乙酮的降解动力学。气相色谱-质谱联用仪(GC/MS)和离子色谱(IC)的分析结果显示,臭氧化降解苯乙酮的中间产物主要包括苯酚、邻羟基苯乙酮、酒石酸、乙酸和草酸等物质,在此基础上提出了臭氧化苯乙酮的可能降解历程。

Acetophenone（ACP）was degraded by ozonation,and the rate constants of ACP reaction with ozone and ·OH radicals were calculated using the relative method.The results indicated that ACP could be degraded effectively by ozone,and that the rate constants of ACP with ozone and OH radicals were 0.163L·mol-1·s-1 and 7.07×109 L·mol-1·s-1,respectively.The experimental results at different pHs showed that two calculated reaction rate constants could forecast the evolution of ACP concentration in the process of its ozonation well.Intermediates detected by GC-MS and ion chromatography（IC）included phenol,2-hydroxyacetophenone,tartaric acid,acetic acid and oxalic acid,on the basis of which the possible mechanism of ozonation of ACP was put forward.