| 摘要 |
<p>PURPOSE:To prevent mold fungi in an aeration tank from being produced and prevent bulking from occuring by adding N-component to maintain the ratio of N/C at a proper value when the N in various components of inflow sewage becomes short. CONSTITUTION:Inflow sewage 1 is sent to a final sedimentation basin 7 by way of a grit chamber 2, an initial aeration tank 4, an initial sedimentation basin 5 and an aeration tank 6, whereby it is subjected activated sludge treatment. In this case, an NH3 calculator 12 and an automatic measuring device 13 for total organic carbon for measuring N and C of the sedimentation basin 5 are mounted and the information having been measured with these devices is inputted to a control unit 17. When these input values, in the ratios of N/C, become less than a certain assigned value (for example, 3/100, 4/100 or 5/100), a pump 14 is started to flow 18 the liquid containing N component from an N source 11 into the tank 4 and to mix it therein, thereby making up the insufficient portion of N. As a result, the bulking in the tank 6 may be prevented from occuring.</p> |
