The present study was classified into two sections. In the first, a kinetic analysis of the oxidation of phenol in aqueous solution over a supported (0.7% Pt)/Al2O3 catalyst was investigated at atmospheric pressure in a batch operating system. The kinetic analysis proved that the reaction consists of two mechanisms, and that the initial rate and steady state activity regimes which exhibited first order behavior with respect to phenol concentration. The reaction rates show an unusual dependence on catalyst loading which suggested a heterogeneous-homogenous free radical mechanism. Phenol removal can be increased by increasing the amount of oxygen gas but at higher flow rates of oxygen a retarding effect of oxygen on phenol oxidation was observed. In the second section, a comparative study of the catalytical wet oxidation (CWO) of phenol in two different types of flow reactors (i.e., falling film and back mixing reactors) was carried out and design parameters such as inlet temperatures, residence time of reactants and catalyst loading in the reactors were used to establish similarity reaction conditions in the two reactors. The study supports the following conclusions: The oxidation rate of phenol was low because of the solubility of oxygen under atmospheric conditions. At low flow rates of liquid reactant the falling film reactor showed a better performance as a result of its lower resistance to mass and heat transfer while the result is completely different at higher liquid flow rates. Non-isothermal operation showed that water evaporation has a strong impact on phenol conversion and must be taken into account in scale up and adiabatic CWO reactor design. Neglecting evaporation can lead to erroneous calculation of the exit stream phenol conversion and temperature. The power law technique has been utilized to correlate the phenol conversion with the operating parameters in the two reactors.