| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an efficient water treatment method combined with anaerobic and aerobic treatments. <P>SOLUTION: The water treatment method comprises introducing anaerobically treated water to an activated sludge tank and intermittently aerating the activated sludge tank, in the water treatment method for subjecting anaerobically treated waste water (anaerobically treated water) to aerobic treatment by an activated sludge method. Here, an oxygen-free state is formed in stopping the aeration to cause nitric acid respiration and to promote the formation of activated sludge flocculation. The water quality of the activated sludge treated water is thereby improved, the filiform bacteria and streptomyces in the activated sludge tank are prevented from becoming dominant and further the scum in the inflow section to a precipitation tank disposed downstream of the activated sludge tank and the floating scum by denitrification are prevented. Also, the aeration time and stop time are determined with the concentration of the nitrate nitrogen in the activated sludge as an index. <P>COPYRIGHT: (C)2004,JPO</p> |
