| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce aeration load of sewage in an aeration tank and also to increase the capacity of cleaning treatment of the reaction tank. SOLUTION: In the sewage treatment system, sewage is passed through a distribution tank 9 and air mixing pipes 10. Shower pipes 45, through which sewage is spouted on the surface of sewage in an aeration tank 11, are arranged. Therefor, floating material (floating sludge, floating scum and gas such as methane) in the aeration tank 11 is beaten by sewage and both floating scum and gas such as methane are made easily separable from floating sludge. Floating sludge sinks and is mixed with activated sludge and becomes activated sludge in which oil content or the like is little and inorganic tendency is strong. Furthermore, sewage feed pipes 46 inserted into sewage from the surface of sewage in the aeration tank 11 are arranged. Therefore, sewage is uniformly supplied to the aeration tank 11 and activation is performed.</p> |
