| 摘要 |
PURPOSE:To obtain good treated water, by providing a membrane separator to the flush washing system of the reaction tank of a fixed bed type waste water treatment apparatus to allow treated water after wasting to pass through a membrane and returning bacterial cell-containing non-transmitted treated water to the reaction tank. CONSTITUTION:When flush washing is performed at the time of long-term operation, the treated water in a storage tank 6 is sent to a membrane separator while the treated water transmitted through the membrane of said separator is discharged out of the system. The treated water not transmitted through the membrane is guided to a flush washing water supply pipe 15, and a flush washing water supply valve 17 and a storage tank recirculation valve 16 are controlled to send a proper amount of said water to a reaction tank 3 to perform the flush washing of said tank 3. By this method, good treated water is obtained even at the time of flush washing and the lowering of treatment efficiency after flush washing is prevented. |
