| 摘要 |
<p>Water treatment sedimentation basin has overflow weir rim extended with respect to in comparison with the length of the overflow pipe to regulate the basin water level : A waste water treatment basin (2) has a sub-surface discharge system (3) drawing water from the basin via a passage. The passage has a water holding unit (5) with an overflow edge (14) which maintains a given water level (12) in the basin. The basin also has a sludge or concentrate removal outlet. Especially the length of the overflow edge (14) is extended by a further overflow edge (14'), in comparison with the length of a simple overflow weir or overflow pipe. The overflow drop height is reduced in comparison to that of a simple overflow weir or overflow pipe, which bears the same load of clear water. The combined total overall length of the overflow edges (14) is set to create an overflow drop of preferably 0.05 m while the basin receives water at its nominal dry weather load, and at a maximum of 1.5 m. The overflow pipe (15) has preferably an oval or polygonal cross section.</p> |
