| 摘要 |
<p>PURPOSE:To prevent the production of excess sludge, by introducing a waste water containing a biologically oxidizable constituent into an activated sludge unit and a biological diaphragm contact oxidizer and mixing the discharge sludge from the activated sludge unit with that from the oxidizer and performing the aerobic digestion etc. of the mixed sludge. CONSTITUTION:About 97 to 70 % of the waste water from an inlet pipe 1 is introduced into an activated sludge aeration vessel 2. The rest of the waste water is introduced into a biological diaphragm unit 13. The discharge sludge from the aeration vessel 2 is separated in a sludge sedimentation vessel 3. One part of the separated sludge is returned to the aeration vessel 2 and the other part is supplied to a digestion vessel 15. The discharged sludge from the diaphragm unit 13 is removed of filtered water 16 by a biological diaphragm sludge separating screen 14 and then conveyed to the digestion vessel 15, wherein the mixed sludge is aerobically digested. The digested sludge is introduced into the aeration vessel 2 and the biological diaphragm unit 13 through a return pipe 17. As a result, excess sludge is hardly produced and the quality of the treated water and the stability of the activated sludge are raised.</p> |
