The treatment of aniline by catalytic wet air oxidation (CWAO) was studied in a bubble reactor. The experiments were performed to investigate the effects of catalyst loading, temperature, reaction time, air flow rate, and pressure on aniline removal. The catalytic effects of the prepared nanostructured catalysts, CuO/CeO2 (10% wt) and NiO/Al2O3 (10% wt), on the CWAO treatment efficiency were also examined and compared. The prepared catalysts seem to be active having an aniline removal of 45.7% with CuO/CeO2 and 41.9% with NiO/Al2O3. The amount of N-2 formed was approximately the same for both of the catalysts. (C) 2012 Elsevier Ltd. All rights reserved.