The catalytic wet air oxidation of phenol using activated carbon has been performedin a laboratory trickle bed reactor over a wide range of operating variables (PO2, T, FL and Cph,o)and hydrodynamic conditions. The influence of different start-up procedures (saturation ofactivated carbon) has also been tested. Further improvement of activity and stability has beenchecked for by using dynamic TBR operation concept or impregnated Fe/carbon catalyst. Theresults obtained confirm that the combination of Trickle Bed Reactor and active carbon can leadto an intensified treatment of phenolic waste water.