| 摘要 |
<p>The dentifrication of the sewage in the activating tank of a purificn. plant takes place during a variable period of time, whilst the feed of atmos. oxygen is cut off. After the supply of air has been interrupted, the falling off of the oxygen content is measured, and the feed is only reconnected, when, after the bottom limit for the oxygen content has been reached, a predetermined period of time has elapsed. The bottom limit is approx. 0.5mg O2/l. The interval of time elapsing between the periods when the oxygen supply is cut off, is selected dependently upon the delivery of raw sewage into the plant. Provide a process which gives full control over the denitrification process, so that the activated sludge is not killed off. There is no denitrification tank as such, so that the layout is simplified.</p> |
