This method is suitable for when decontamination is the objective. Good preliminary concentration is particularly important.
Sludge which is produced is aerated in a closed tank (air or O2). When let out the sludge is conducted via a heat exchanger which preheats the freshly added sludge. Heat is released during the aerobic decomposition of organic matter – with good tank insulation and sufficient solids content temperatures of 50-70°C are achieved. Stabilisation is generally carried out in two stages (total stabilisation time = 6-8 d). Exhaust air (strong odour) is either blown into the activation basin or cleaned in biofilters.
In addition to the possibility of decontamination, aerobic -thermophilic stabilisation has the advantage of making the inflow to the digestion tank more uniform and is therefore suitable as a preliminary stage addition to an existing digestion process.