Abstract: A sewage treatment system which presents a main flow line and a recirculating line, the former for flock which has appreciated in size due to the addition of a polymer and passage through an area of agitation/turbulence and the latter for the return of small sized flock to the agitator/turbulence area for size increase. The passageways of the system include movable flaps, serving recirculation purposes, and a ledge or flutter for current creation and flock build-up. Raw liquid sewage enters the system, where the outlet leads to a belt press and/or a dry bed to cake the resulting sludge.