| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently remove phosphorus and ammoniacal nitrogen at reduced costs incurred in equipment and operation when raw water containing phosphorus and ammoniacal nitrogen is treated by a dephosphorization process, a nitrite- conversion process and a denitrogenation process. SOLUTION: Raw water is fed to a nitrite-conversion process 1 and at least a part of ammoniacal nitrogen in the raw water is converted to nitrite nitrogen which is fed to a dephosphorization process 2 afterwards to remove the phosphorus. Then, it is fed to a denitrogenation process 3 to perform a denitrogenation treatment by reacting the ammoniacal nitrogen and nitrite nitrogen by means of the action of denitrifying microorganisms in which the ammoniacal nitrogen acts as an electron donor and nitrite nitrogen as an electron acceptor. Alternatively, raw water is fed to a nitrite-conversion process 1 and ammoniacal nitrogen is converted to nitrite nitrogen. Subsequently, it is fed to a denitrogenation process 3 to perform a denitrogenation process and then, fed to a dephosphorization process 2 to remove the phosphorus.</p> |
