| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem in which: a combined private sewage treatment system having treatment object persons of 5-50 adopts a treatment mode in which anaerobic treatment and aerobic treatment are combined, and is mounted with a circulation function of transferring a part of aerobically treated treatment water to anaerobic treatment and further a cleaning function of transferring excess sludge generated by decomposing a suspended solids (SS) and a polluted matter captured in a filter bed of aerobic treatment to anaerobic treatment as cleaning waste water; an air lift pump that is inexpensive, simple structure and hardly breaks down is frequently employed for transferring circulation water and cleaning waste water, however, circulation water and cleaning waste water have different transfer water amounts, thereby there is a case in which transfer is performed by respective different air lift pumps, and cost is taken, and operation at a maintenance inspection time becomes complex.SOLUTION: In the present invention, circulation water and cleaning waste water can be transferred by the same air lift pump, so that cost reduction and reduction of maintenance inspection operation can be achieved. |
