| 摘要 |
PURPOSE:To prevent the clogging of a membrane, to easily set the operating condition of the membrane treating device and to improve the recovery rate of treated water in the entire system by treating raw water with a biological filter and membrane in this order. CONSTITUTION:Raw water 1 is firstly supplied to a biological filter 3 through a raw water feed line 2 and pretreated by the filter 3. The pretreated water is then supplied to a membrane treating device 5 through a line 4 and treated by the device 5. The water permeated through the membrane is passed through a water line 6 and discharged as treated water 7. Since the raw water 1 is treated in this way, the load of suspended impurities on the device 5 is lowered, and the fluctuation width of the quality of the raw water is decreased. |
