| 摘要 |
<p>PURPOSE:To enhance flocculating property and to improve the cleanliness of the separated water by a centrifugal thickening machine and the rate of recovering solids by adding activated sludge to a sludge mixture from a thickener, etc., while maintaining an aerobic atmosphere, thereby producing exopolymers. CONSTITUTION:Treated water 1 is treated in an initial settling basin 2, an aeration tank 5 and a final settling basin 6. The finally settled sludge 8 is returned as the activated sludge 4 and the excess sludge 9 is mixed with the initially settled sludge 3 in the thickener 10. While the sludge mixture 11 flows through a pipeline 12 into a concentrated sludge receiving tank 13, the excess sludge 9 of at least one treating plant enters the aeration tank 16 as it is. This sludge is mixed with the sludge mixture 11 while the aerobic atmosphere is maintained at the intermediate point of a carrying line 17. The sludge mixture enters an agitating and mixing tank 18. Flocs are coarsened by the flocculation effect of the exopolymers produced in the tank. The cleanliness of the separated liquid 20 from the centrifugal thickening machine 24 and the rate of recovering the solids are improved.</p> |
