| 摘要 |
1404777 Biological filters ECODYNE CORP 29 Sept 1972 [26 Nov 1971] 44991/72 Heading C1C An apparatus for biologically purifying waste liquid comprises a housing 12 containing a biological filter bed 12 (e.g. polypropylene rings or saddles), surrounding a central passage 26 which is associated with surface aerator 30 (or with a diffuser, not shown), liquid inlet 14, clarified liquid outlet conduit 16 and sedimentation zone 38. In use the bed is maintained submerged and the liquid is circulated in a circuit in which it passes downwardly through the bed 12 and upwardly through passage 26, and is uniformly through the bed 12 and upwardly through passage 26, and is uniformly distributed over bed 12 and aerated by aerator 30. The clarified liquid is discharged through conduit 16 and weir box 18 to conduit 20. Solids settling in zone 38 are periodically removed. |
