| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to stably treat waste water requiring a biological treatment without requiring intricate waste water treatment management by executing the biological treatment of an anaerobe fixed bed and a back washing treatment using an inert gas in succession thereto in combination at the time of biologically treating the waste water. SOLUTION: The waste water of a waste water raw water tank 1 is supplied to a biological treating vessel 4. This biological treating vessel 4 is the anaerobe fixed bed and the packing materials of this fixed bed 41 is porous ores. Since the treating vessel is the fixed bed 41, a living thing concn. is maintained at a high contration and the stable execution of the biological treatment is possible. The inert gas (gaseous nitrogen) in a buffer tank 5 is introduced into the biological treating vessel 4 after the execution of the biological treatment or after the completion of treatment of the waste water of the prescribed flow rate. This inert gas is injected from an air diffusion pipe 42 and, therefore, the back washing of the fixed bed 41 from below is possible. The treated water formed in the biological treating vessel 4 after the end of the back washing is sent to a treated water tank 6. The back washing water is sent to a back washing waste water tank 7. |
