A waste treatment system and method for treating a substantially liquid waste stream. The waste treatment system includes a conditioning stage for conditioning the waste stream for treatment. A metal ion generation stage is provided for generating metal ions for disinfection of the waste stream and for catalytic oxidation. A wet oxidation stage is provided in fluid flow communication with the metal ion generation stage for denaturing the waste stream using an oxygen-containing gas. A chelation stage in fluid flow communication with the oxidation stage is provided for deactivating metal ions in the waste stream.
