Primary sludge and secondary sludge (from biological activated sludge plants) can be costly waste products from waste water treatment processes.
Most sludges consist, in part, of organic material which is amenable to degradation by microorganisms. This property can be used as the basis for treatment processes where oxygen supplied to the wet sludge promotes aerobic biological activity, and decomposition of the organic material to CO2 and water, so reducing the solids present in the sludge. This has the potential to save alternative sludge treatment or disposal costs.
High purity oxygen can be used successfully to accelerate Sludge Digestion, and, within the activated sludge process, to promote sludge digestion in situ.
The use of oxygen as opposed to air raises the temperature of an aerobic digestion process, leading to the easy maintenance of thermophilic conditions if required for sludge disinfection.