| 摘要 |
<p>PROBLEM TO BE SOLVED: To exactly set DO (dissolved oxygen concn.) by setting the relation between the DO value of an i-th cell and a total oxygen moving capacity coefft. or oxygen consumption rate in such a manner that this relation satisfies the specific equation at the time of setting the blasting rates to the aeration tank divided to the plural cells and the DO. SOLUTION: Air is sent from a fan 1 through an air diffuser 2 to the treating water in the respective cells in the aeration tank 3 divided to the five cells where a sewage treatment is executed by utilizing microorganisms. Activated sludge is circulated to the tank 3. In such a case, the DO values or blasting rates by each of the respective cells of the tank 3 are set by a DO control arithmetic means in accordance with the equation, where Q is defined as a flow rate, Vi as the volume of the i-th cell, Cs as saturated DO, Ci as DO value of the liquid mixture in the i-th cell, KLai as the KLa in the i-th cell and Rri as Rr of the liquid mixture in the i-th cell. This DO control arithmetic means is provided with setting means for regulating the blasting by setting the specified blasting rate at the respective cells of the tank 3 on a dialog box and setting the DO value of the cells to be subjected to DO control.</p> |
