| 摘要 |
<p>PROBLEM TO BE SOLVED: To enhance the sewage purification treatment capacity of the equipment by supplying divided sewage to be treated to an aeration tank and the other divided sewage for adjustment to a concentration tank located subsequently to the aeration tank and returning the treated sewage from the concentration tank to a sewage inflow section again as a part of feed sewage. SOLUTION: In this method, when feed sewage is allowed to flow into a discharge pipe 10 from a supply port 9a, the feed sewage flows down through an orifice 11 placed in the discharge port 10a and is supplied to an aeration tank 3 as a prescribed amount of divided sewage to be treated. Then, the divided sewage is purified with activated sludge in the aeration tank 3 and the resulting treated sludge is transferred from the aeration tank 3 to a sedimentation tank 4 to separate it into settled sludge and supernatant water. The supernatant water is transferred from an overflow trough 4a to a discharge section 5 and there, disinfected with a chlorine-based disinfectant and discharged into a river or the like and on the other hand, the concentrated settled sludge is transferred to a distribution section 6. In the distribution section 6, the settled sludge is divided into a prescribed amount of return sludge and the other excess sludge and the return sludge is returned to a sewage inflow section 1 and the excess sludge is transferred to a concentration tank 7. The settled excess sludge further concentrated in the concentration tank 7 is transferred to the storage tank 8 and thereafter, incinerated or used for materials in a wide variety of application fields.</p> |
