The catalytic wet air oxidation of oxygenated pollutants has been investigated in a co-current downflow trickle-bed reactor, over a temperature range 423-473 K at a total pressure of 5 MPa, using a 2.8% Ru/TiO2 catalyst. When the catalyst was employed under integral conditions (high catalyst mass/liquid flow ratio, approximate residence time of 5.1 h g(Ru) L-1) it was possible to convert 5 g L-1 aqueous solutions of cyclohexanol, succinic acid, and acetic acid into CO2 and H2O. Experimental kinetic data were measured, in the reactor operating differentially at 463 K, at different conversions of succinic acid obtained at each step of the successive recycling of the reaction medium. The intermediate compounds detected were identified as acrylic and acetic acid. For the six main reactions identified, the reaction rates were described by Langmuir-Hinshelwood type rate equations, assuming competitive adsorption of liquid-phase components. The comparison of the experimental data with kinetic modeling showed an excellent agreement. The model indicates a very low adsorption of acetic acid (K-ACE less than or equal to 0.005 L mmol(-1)) compared to succinic and acrylic acid (K-SUC = 0.13 and K-ACR = 0.16 L mmol(-1)), even though the kinetic constants were of the same order of magnitude. Long-term experiments with this catalyst demonstrate its stability under the reaction conditions used.