| 摘要 |
<p>PROBLEM TO BE SOLVED: To properly control the activity of an active sludge by evaluating the influence of toxic materials on the active sludge regardless of the conditions of sewage.SOLUTION: An oxygen utilization rate AR when fresh water only is a test liquid is compared to that A of the test liquid except the fresh water, and magnitude relationship between both oxygen utilization rates is used as an important judgment indication for the proper activity control of an active sludge. Besides, a conversion point PT at which the oxygen utilization rate A of the active sludge becomes maximum is recognized by changing the prescribed condition F influencing that rate of the active sludge and also, a limit point PB at which the rate A is below the reference data AR is recognized. Those conversion and limit points PT and PB are used as the indicators for controlling the activity of the active sludge, and it becomes possible to control the oxygen utilization rate A of the active sludge to at least adequate rate by adopting the condition F at which the oxygen utilization rate A of the active sludge is between the conversion point PT and the limit point PB.</p> |
