| 摘要 |
<p>PURPOSE: To simplify the adjustment of the circulating amt. of treated water by always returning a predetermined amt. of treated water in a treatment tank using aerobic bacteria to the upper part of an anaerobic filter bed tank by an air lift pump and to always circulate a definite amt. of treated water and to prevent the outflow of fine 88 to obtain highly treated water. CONSTITUTION: Biologically filtered treated water in a treatment tank 5 is always returned to the upper part of an anaerobic filter bed tank 3 at a constant flow rate by a circulating air lift pump 33. Therefore, sewage is recycled from the anaerobic filter bed tank to the treatment tank 5 and, even if the circulating amt. of the air lift pump 33 is changed, it becomes unnecessary to adjust the water sending amt. of the air lift pump 33 sending water from a solid removing second chamber 2 to the anaerobic filter bed tank 3. Even when the air lift pump 33 is operated, sewage is always recycled to three tanks 2, 3, 5 and, therefore, the temporary lowering of the water level in the treatment tank 5 is eliminated and a definite amt. of treated water can be always circulated.</p> |
