Wet oxidation of activated sludge

This paper describes the potential for wet oxidation (WO) processes to treat activated sludge under stoichiometric oxygen conditions. Tests were carried out at temperatures ranging from 200 to 300°C at retention times of 10, 30 and 60 min. Temperature proved to be the most significant parameter, followed by retention time and oxygen overpressure. A considerable reduction in sludge volume and COD was generally obtained, producing an effluent liquor with a high oxygen demand and relatively stable residual solids. Simplified empirical equations were developed from the experimental data to describe the transformation pattern of the organic and inorganic components of the activated sludge in a WO environment at different temperatures.