The organic fraction is first solubilised in the acid and alkaline oxidative hydrolysis phases and is then converted into oligosaccharides, peptones and free amino acids, which are totally biodegradable. The first phases completely break down the organic and inorganic compounds, while the subsequent phases consist of sedimentation and neutralisation.

The use of an oxidiser yields better results for sludge disintegration and produces various soluble compounds, often dominated by a series of short-chain fatty acids (SCFA) such as acetate, formate, propionate and valerate, which improve biogas production yield of the subsequent anaerobic digestion process.

The product of the conversion process is sent to the anaerobic digester or, in the absence of such directly to dehydration for solid/liquid separation section. The dehydrated sludge is sent to the top of the purification plant.

The process does not alter the possible usage of the sewage sludge but does make it more stable, sanitised and suitable for application in agriculture.