| 摘要 |
<p>PURPOSE:To provide a nitrification process always stabilized by measuring NH4-N concentration in the water near an outlet of an aeration tank and controlling the volume of air to be of a fixed value of concentration. CONSTITUTION:Raw water 1 containing nitrogen compound and organic sludge is introduced into an aeration tank 2, and organic substances decomposable biologically are decomposed and removed by the action of BOD oxidizing bacteria. Also, NH4-N contained in the raw water is oxidized into NOx-N flows into a sedimentation tank 4, where sludge is separated by gravity settling to separate treated water 3. The air flow nd the supplus sludge extraction flow are controlled in such a manner as to make NH4-N concentration come to a fixed value in the area near the outlet of the aeration tank measured by a NH4-N sensor 10. By this arrangement, a stabilized nitrification process is performed throughout the year.</p> |
