IMPROVED WASTEWATER TREATMENT PLANT AND METHOD

摘要

A method and apparatus for increasing the capacity of an activated sludge wastewater treatment plant which utilizes microscreens in conjunction with rotating biological contactors that are placed in the primary settling tank, the aeration tank and the final clarification tank. A rotatable microscreen is placed upstream of the primary settling tank and downstream of the final clarification tank. The result is a more efficient and less energy consuming system which reduces the organic loads. Preferably, the microscreening preceding the biological treatment stage will have a mesh size in the range of about 50-200 mesh and the microscreen placed after the biological treatment stage will have a mesh size in the range of 6-44 microns. Additional benefits are obtained in recycling the treated water which is passed through the rotating biological contactor as well as utilizing it to aid in rotating the contactor. Another advantage of the system of this invention is that it can be readily adapted to an existing wastewater treatment plant in order to upgrade its capacity without substantially increasing capital investment and is adaptable to a new facility with benefits at low energy consumption and minimal land requirement.