| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a water purification technique capable of removing nitrogen and phosphorus as a countermeasure against the eutrophication in a closed water area. <P>SOLUTION: Water to be treated is clean water flowing into the closed water area and having the BOD value less than 10 mg/L and DO value more than 2 mg/L. The method comprises the step of making the water to be treated anaerobic and the step of making the water anaerobic after aerobic treatment. In the initial stage of the step of making the water anaerobic, an organic component derived from nature such as sludge or highly polluted water is added to the water to be treated in order to keep on making the water anaerobic until the DO value of the water is lowered to be less than 2 mg/L due to the consumption or the decrease of oxygen in the water to be treated and of removing the nitrogen in the water with naturally-occurring denitrifying bacteria and the phosphorus with naturally-occurring phosphorus accumulation bacteria, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
