an apparatus for the treatment of faeces , includes a tank for housing faeces that has been subjected to treatment . there is a process vessel in which the faeces is treated and which is located inside the tank having an inlet for feeding faeces into the process vessel . a rotary device is provided for stirring the faeces in the process vessel and for introducing oxygen into the faeces , which is operable in two modes of operation at different speeds of rotation . a partitioning member separates the interior of the process vessel in a lower and an upper portion , while at the same time allowing communication between the lower and upper portions . the rotary device is arranged to at least cause a suction of material mainly from the lower compartment in a first mode of operation and into the rotary device .