| 摘要 |
<p>Multi-step biological sewage treatment plant comprising at least two treatment or aeration tanks (31, 32, 33) having an inlet (35) for sewage, an outlet (38) for treated water and a conduit for air supply (31A, 32A, 33A) down in each treatment tank (31, 32, 33), and further comprising a settling tank (34) as a final treatment step. The air supply conduit in each treatment tank (31, 32, 33) is provided with its outlet relatively close to a vertical separating wall (49) in the treatment tank (31). A baffle plate (41A, 42A) extends from a level above the operational water level in the treatment tank (31, 32) at an inclination downwards-inwards towards a vertical wall part in the tank at a space from said vertical separating wall, for establishing a clarifier chamber (41, 42) which is separated from the main part of the tank, but communicates with the latter through a lower opening in the clarifier chamber. The clarifier chamber (41, 42) has a volume which constitutes a small fraction of the total volume of the treatment tank. The treatment tanks (31, 32, 33) are surrounded by a common vertical and cylindrical outer wall (30A). The settling tank (34) is surrounded by a vertical cylindrical inner wall (30B). The treatment tanks (31, 32, 33) are formed as sections between said outer cylindrical wall (30A) and said inner cylindrical wall (30B), and the separating walls between said treatment tanks (31, 32, 33) are provided transversely from the outer cylindrical wall to the inner cylindrical wall, and are provided with overflow sills (46, 47) from the clarifier chamber (41, 42) in the treatment tank (31, 32) concerned, to the following treatment tank (32, 33). This sewage treatment plant is primarily intended for a small number of apartments or the like and can be buried underground.</p> |
