| 摘要 |
<p>PURPOSE:To treat sewage at a high removal rate with a simple everyday operating control, by changing the form of an activated sludge bed vertically provided in a tank at every unit of plural sewage disposal tanks to carry out treatment ranging from high-load to low-load treatment with plural sewage disposal tanks. CONSTITUTION:A sewage inlet pipe 1, a solid removing device 2, the sewage disposal tanks 13-15, a settling tank 16, a bactericidal tank 17, a treated water discharge pipe 5, an air inlet pipe 39, aeration pipes 41 and 51, etc., are provided. The surface area of a long cylindrical core body covered with a porous material in plural activated sludge beds 52 and 53 is successively increased in the order arranged at every sewage disposal tank unit, or the area is equalized between the adjacent sewage disposal tanks and at least the area in the final sewage disposal tank is made larger than that in the initial sewage disposal tank to change the growth ratio of the aerobes and anaerobes constituting the activated sludge and their distribution at every sewage disposal tank. As a result, the everyday operating control is relatively simplified, and sewage treatment can be always carried out at a high removal rate.</p> |
