Wet air oxidation (WAO) was studied as an alternative to wastewater treatment solids (biosolids) incineration. WAO of biosolids was performed in the presence of a monolithic copper/titania catalyst. The total pressures were in the range 4.0-4.7 MPa, and the temperature was 508 K. The how pattern in the horizontal tube reactor was plug flow. Compared to non-catalytic runs, the presence of the catalyst increased the oxidation of biosolids significantly.