| 摘要 |
<p>PURPOSE:To perform stable treatment by providing a sensor for detecting the concn. of suspended matter contained in the mixed liquid in a tank and controlling the time and amount of drawing sludge on the basis of it. CONSTITUTION:After introducing raw water, it is subjected to biological treatment by performing continuous aeration or intermittent aeration. MLSS (cm<3>) is measured in such a state that the inside of a tank is sufficiently agitated by introduction of raw water. The sensor of an MLSS densitometer is positioned near a drawing port of sludge below the interface of sludge. The measured value of concn. obtained from the MLSS densitometer is inputted to a controlling device having calculation function and the amount of drawing sludge is calculated on the basis of the previously inputted value and a drawing pump 11 of sludge is actuated by the command output from the controlling device to start drawing sludge. Thereby raw water can be stably treated.</p> |
