Nitration of nitrobenzene in Fenton's processes

In order to asses the key species involved in NB nitration mechanism, additional experiments were performed in the presence of NO2-orNO3-. In dark systems, 1,3-DNB yield significantly increased with increasing NO2-0, while it was not affected by the presence of NO3-. In contrast, 1,3-DNB yields were higher and more strongly affected by the additive concentration in UV/NO3- systems than in UV/HNO2/NO2- systems. Dark experiments performed at pH 1.5 in excess of HNO2 along with UV/NO3- tests conducted in the presence of 2-propanol show that hydroxyl radicals play an important role in NB nitration since NB molecule does not react with the nitrating agents ONOOH, NO or NO2. The results indicate that, in the experimental domain tested, the prevailing NB nitration pathway involves the reaction between the OH-NB adduct and NO2 radicals.