Conventional Activated Sludge Process
Conventional activated sludge systems commonly include an aeration tank and secondary clarifier. Aerobic biomass reduces the biochemical oxygen demand (BOD) and ammonia concentrations in the aeration tank. Biomass then flows to the secondary clarifier, where it is separated into clarified water and thickened biomass by gravity sedimentation. The clarified treated water overflows at the top of the secondary clarifier, and the thickened biomass is recycled to the aeration tank or managed at sludge dewatering facilities.