| 摘要 |
<p>PURPOSE:To enhance a BOD removal ratio, by specifying the MLSSs and the sludge days-old of the liquids from an aeration process for blowing oxygen-containing gas into sludge water in a concentrated aeration part and an aeration process for blowing oxygen-containing gas in a recirculation aeration part. CONSTITUTION:Sewage to be treated is supplied to a concentrated aeration part 6 through a pipe 14 to be subjected to concentrated aeration in the concentrated aeration part having a min. volume capable of dissolving a necessary oxygen amount corresponding to an inflow BOD amount and activated sludge, an org. substance and oxygen are almost perfectly mixed. This liquid mixture is raised by the lift effect due to air blown from a diffuser 18 and flowed into a carrying- away part 7 to receive the separation of gas such as residual air or CO2. Subsequently, the liquid mixture is flowed into a separation part 10 from a confluent part 8 through the passage under a guide plate 4a and sucked into a recirculation aeration part 9 by the air lift effect of the high concn. oxygen gas blown into said aeration part 9 and rises therethrough to be returned to the confluent part.</p> |
