| 摘要 |
<p>PURPOSE:To improve sewage treating capacity by forming plural stages of descending flow of sewage and ascending flow provided with filter media in an aeration tank in a sewage treating device and opening air supply pipes in the descending flow. CONSTITUTION:Plural partition walls 4a-4e are provided in an aeration tank body 1 in a sewage treating device to form flow passages 5a-5f snaking vertically in the tank 1. The sewage supplied from an introducing part 2 flows downward in the descending flow passages 5a, 5c, 5e, and is again circulated by a pump 8 to 5a after flowing through the ascending flow passages. Air supply pipes 7 are opened in the descending flow passages 5a, 5c, 5e for the sewage and the air ascends against the descending flow of the sewage, in the form of fine foam, thereby providing an excellent aerating effect. Contact filter media 6 such as porous material, filber material or the like are packed in the passages 5b, 5d, 5f and the activity of the microorganisms sticking on the media 6 is doubled by the oxygen supplied from the foam to improve the cleaning-up effect for the sewage. The sewage is discharged as clean water from the discharging part 3.</p> |
