The degradation of high concentrations of phenol (1g/dm(-3)) in aqueous media at high temperatures (100-190 degrees C) and pressures (2.0 MPa) has been studied by catalytic wet air oxidation in a trickle-bed reactor. The effect of reaction temperature, weight hourly space velocity (WHSV) and hydrogen peroxide concentration on phenol concentration, total organic carbon (TOC) and chemical oxygen demand (COD) conversion by using a commercial copper catalyst has been investigated. At 150 degrees C, TOC removal increased by 28% with the WHSV of 62.5 h(-1). The addition of hydrogen peroxide as a free radical promoter significantly enhanced the depletion rate of phenol. A kinetic study has been carried out leading to the determination of the kinetic constants for the removal of TOC. (c) 2005 Society of Chemical Industry.