| abstract |
(57) [Summary] [PROBLEMS] To efficiently remove ammonia contained in wastewater. SOLUTION: In a first step reaction tank 1, an ammonia-containing wastewater introduced from outside the system is brought into contact with microorganisms under an aerobic condition to oxidize an ammonia component contained in a liquid phase to nitrous acid. The treated water of the first step reaction tank 1 is brought into contact with microorganisms under anaerobic conditions in the second step reaction tank 2 to convert the ammonia component and the nitrite component contained in the liquid phase into nitrogen gas. . In the first step reaction tank 1, activated sludge 1 Seed sludge supply means 11 for supplying seed sludge containing the ammonia oxidizing bacteria group acclimated by 11, the ammonia oxidizing bacteria medium 112 and the nitrite oxidizing bacteria inhibitor 113 to the same tank 1 is attached. Further, the nitrite-oxidizing bacteria inhibitor 113 is intermittently supplied to the tank 1, whereby nitrite-producing nitrification is maintained. |