| 摘要 |
<p>An oxidation ditch of an activated sludge waste water treatment plant defines an endless open channel round which the water flows. A separator 3 defines a quiescent zone within the channel and has overflows 9 for clarified water and a slotted floor 5 by which settled solids return to the channel. Upstream and downstream walls 7, 8 of the separator incorporate movable or removable gates 11, 12 which normally extend above the water surface (Fig. 3a). When scum 10 accumulates in the separator, the gates are opened, so that the water current carries the scum away to be broken up by an aerator or removed by a separate overflow 13. <IMAGE></p> |
