| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the subject biological treatment method capable of always stably preventing the generation of a malodor even if the inflow amt. of sewage is varied. SOLUTION: Org. sewage is received in a pretreatment process 1 and subsequently biologically treated in biological treatment processes 3, 4 and generated sludges 18, 19 are introduced into a sludge treatment process C to be treated by the contact with a filler containing humus and the obtained humus-containing separated soln. and/or sludge 21 is returned to the pretreatment process 1. In this biological treatment method, the return amt. 21 of the humus-containing separated soln. and/or sludge is regulated so as to follow the inflow amt. of sewage 16 flowing in the pretreatment process 1 in a constant ratio with respect to the inflow amt. of sewage and, concretely, the regulation of the return amt. is performed by measuring the inflow amt. of sewage 16 by an inflow flowmeter 13 and controlling the number of rotations of a return pump 15 by a ratio setting device 14 or integrating an inflow amt. at every one hour and controlling the operation time of the return pump of one hour in proportion to the integrated quantity.</p> |
