Pyrene and fluoranthene. typical polycyclic aromatic hydrocarbons, are very difficult to be removed from water due to their hydrophilic nature and relatively low reactivity towards ozone. In the study. Celoaded activated carbon (Ce-AC) is prepared and used as catalyst to promote pyrene and fluoranthene degradation by ozone. The catalytic activity of Ce-AC is investigated under various experiment conditions. Results indicate both of pyrene and fluoranthene removals are significantly enhanced in Ce-AC + O-3 due to effective generation of hydroxyl radicals (center dot OH), as compared to zonation alone and AC + O-3. The mineral matter present in the activated carbon positively contributes to remove fluoranthene and the optimized cerium loading of AC is 0.3% in ozonation process. Moreover, the toxicity of pyrene is more than that of fluoranthene and the reaction solution's toxicity is substantially reduced by catalytic zonation with Ce-AC. (C) 2012 Elsevier B.V. All rights reserved.