| 摘要 |
<p>PURPOSE:To enhance the supply amount of oxygen for improving the efficiency of purifying waste water, by independently providing a means for circulating water to a filthy water disposal channel formed into a horizontal closed channel and an oxygen supply means for supplying oxygen to the interior of said channel. CONSTITUTION:Waste water having flowed through a sedimentation basin 6 into a ditch 1 is mixed with activated sludge in the ditch 1 and circulated through the ditch 1 by a water circulating means 10. In the water circulating means 10, the removal of nitrogen is performed. Thereafter, the liquid mixture is circulated through an oxygen supply means 11. At this time, the mixed sludge is aerated to accept the supply of oxygen necessary for the oxidation of BOD and nitrifying reaction. Hereon, the oxygen supply means 11 is exclusively used for the supply of oxygen, so that the sufficient amount of oxygen can be supplied. In addition, it is easy to control oxygen supply. At a part apart from the oxygen supply means 11, the amount of dissolved oxygen is reduced to form an anaerobic zone. Hence, denitrifying reaction is accelerated.</p> |
