| 摘要 |
<p>PROBLEM TO BE SOLVED: To control a batchwise activated sludge method keeping the removal of phosphorus well. SOLUTION: In a control method using the ORP meter 10 arranged to a reaction tank 3 to detect the bent point of an ORP curve in a stirring process and subsequently adding 11 short chain fatty acid such as acetic acid to increase a phosphorus discharge speed to shorten a phosphorus discharge time and sufficiently ensuring an aeration time necessary for the absorption of phosphorus, the concn. of phosphorus in treated water is lowered. When the concn. of nitrate nitrogen is high, the discharge of phosphorus simultaneously with denitrification is performed by adding short chain fatty acid such as acetic acid immediately after the start of a stirring process and, after an ORP bent point is detected, an aeration process is performed to raise the phosphorus removing ratio of treated water by a control method sufficiently ensuring a phosphorus absorbing time.</p> |
