Treatment of effluent water streams - using settling tank followed by activated sludge treatment in tray tower with air lift pump to provide recirculation

摘要

Waste water is treated by passing through a settling tank and then an aerated sludge process. The settling tank has a set of baffles to encourage settlement and anaerobic fermentation occurs with breakdown of solids (e.g. paper) into a sludge. The liquor from this settle flows over into a contacter where it flows down over a set of plates to create a zig-zag path. At the side of these is an air lift pump which serves to create a circulatory flow around the tank. This acts as an activated sludge treatment vessel since bacterial growth occurs on the surface of the plates in the presence of the air. Used esp. for treatment of waste water containing human sewage. Allows waste waters from factories, dwelling areas, houses assembly halls etc. to be safely discharged to rivers, moors and seas without a pollution problem.