Biological treatment of sewage

摘要

Sewage is oxygenated and clarified in a tank having an open-bottomed stilling chamber located above an open-topped chamber. Oxygenated sewage is discharged into the stilling chamber where its velocity is reduced, with sewage passing from the stilling chamber into the open-topped chamber being precluded from flowing horizontally along the tank bottom, and upwardly into the clarified sewage.