| 摘要 |
<p>PROBLEM TO BE SOLVED: To control a nitration reaction in water treatment with high precision without using an intricate calculating expression or setting various coefficients. SOLUTION: The concn. of nitrifying bacteria in the aeration tank of a sewage treating device 10 is measured, the substrate concn. and oxygen concn. in the raw water introduced into the aeration tank are also measured, and the respective data are inputted to a computer 36. The behaviors of the respective nitrifying bacteria are determined by computing by using the computer 36 according to the behavior determining program prepared by ruling the three behaviors, i.e., intake of substrate, propagation and extinction, in relation to the existing states of the nitrifying bacteria and its adjacent substrate and oxygen. The predicted values of the nitrifying bacteria concn., treated water substrate concn. and treated water oxygen concn. in the aeration tank 14 after the retention time has elapsed are outputted to a controller 30. The aeration amt. and return sludge concn. of the sewage treating device 10 are feedforward- controlled by the controller 30 based on the respective predicted values and target values.</p> |
