Mesoporous material (MCM-41) supported manganese oxides (MnOx) as catalyst was introduced into ozonation process. The catalytic activity of MnOx/MCM-41 on ozonation of nitrobenzene (NB) was evaluated. Both of the indirect method, using tert-butanol (TBA) as a scavenger, and the direct electron spin resonance (ESR) determination technology were employed to investigate whether the high reactivity of MnOx/MCM-41 on ozonation is ascribed to the promotion of the generation of hydroxyl radicals. Though the presence of TBA has insignificant effect on MnOx/MCM-41 catalytic ozonation of NB, stronger signal intensity of DMPO-OH adduct was observed in MnOx/MCM-41 catalytic ozonation than that of in ozonation alone system. Furthermore, the catalytic performance of MnOx/MCM-41 on ozone in different water background (tap water, prepared inorganic and organic water) was investigated. (C) 2011 Elsevier B.V. All rights reserved.