Degradation of p-nitrotoluene by O_3/H_2O_2 process and oxidation mechanism  

作　　者：于颖慧 马军 侯艳君 高金胜 

机构地区：[1]School of Municipal and Environmental Engineering,Harbin Institute of Technology [2]School of Chemistry and Materials Science,Heilongjiang University

出　　处：《Journal of Harbin Institute of Technology(New Series)》2009年第1期115-120,共6页哈尔滨工业大学学报（英文版）

基　　金：Sponsored by the National Natural Science Foundation of China(Grant No.50378028)

摘　　要：The degradation of p-nitrotoluene by O3/H2O2 process in a bubble contact column was investigated. Effects of the molar ratio of hydrogen peroxide to ozone,pH value and t-butanol on the oxidation process were discussed. It was found that the proper H2O2/O3 molar ratio for the degradation of p-nitrotoluene was around 0.6, different pH values and the presence of t-butanol highly influenced the removal efficiency of p-nitrotoluene. 5-methyl-2-nitrophenol, 2-methyl-5-nitrophenol, (4-nitrophenyl) methanol, 5-(hydroxymethyl)-2-nitro phenol, acetic acid, 2-methylpropane diacid and 2-(hydroxylmethyl)propane diacid were identified as degradation intermediates and products through GC-MS. Radical reaction mechanism and degradation pathway were proposed based on the results of experiments. It is deduced that the benzene ring of p-nitrotoluene can be only destroyed by hydroxyl radicals through a polyhydroxy intermediate pathway. Then unstable polyhydroxy intermediates can be oxidized to different acids with low molecular weight rapidly.The degradation of p-nitrotoluene by O3/H2O2 process in a bubble contact column was investigated. Effects of the molar ratio of hydrogen peroxide to ozone, pH value and t-butanol on the oxidation process were discussed. It was found that the proper H2O2/O3 molar ratio for the degradation of p-nitrotoluene was around 0. 6, different pH values and the presence of t-butanol highly influenced the removal efficiency of p-nitrotoluene. 5-methyl-2-nitrophenol, 2-methyl-5-nitrophenol, （ 4-nitrophenyl ） methanol, 5- （ hydroxymethyl ） -2-nitro phenol, acetic acid, 2-methylpropane diacid and 2-（hydroxylmethyl） propane diacid were identified as degrada- tion intermediates and products through GC-MS. Radical reaction mechanism and degradation pathway were proposed based on the results of experiments. It is deduced that the benzene ring of p-nitrotoluene can be only destroyed by hydroxyl radicals through a polyhydroxy intermediate pathway. Then unstable polyhydroxy intermediates can be oxidized to different acids with low molecular weight rapidly.

关 键 词：P-NITROTOLUENE OZONE hydrogen peroxide advanced oxidation processes 

分 类 号：TQ246.16[化学工程—有机化工] X172[环境科学与工程—环境科学]