| 摘要 |
<p>PURPOSE:To shorten a low BOD state to suppress propagation of filamentous fungus and consequently to obtain a sewage treating device capable of stably preventing filamentous bulking by efficiently absorbing BOD in the raw water in the sludge and oxidizing the BOD by aeration. CONSTITUTION:This sewage treatment unit consists of a plug-flow BOD absorption tank 1 in which raw water 2 is passed as a plug flow and brought into contact with the return sludge pipe 3 into which the sludge is dispensed to absorb the BOD in the raw water in the sludge, an aeration tank 5 in which a liq. mixture 4 introduced from the absorption tank 1 is aerated to aerobically oxidize and decompose BOD, a solid-liq. separation tank 9 for the aerated liq. 8 of the tank 5 and a sludge return device 12 for dispensing a part of the sludge separated in the tank 9 to the tank 1 as the return sludge pipe 3 in the plug flow direction.</p> |
