| 摘要 |
Provided is a biological nitrogen removal method which includes, causing to flow a support having, on the surface portion thereof, a two-layered microbial film which holes, in the outer layer, nitrite type nitrifying bacteria or aerobic bacteria and nitrite type nitrifying bacteria as a dominant species and, in the inner layer, anaerobic ammonia oxidizing bacteria as a dominant species while being surrounded with the nitrite type nitrifying bacteria; and thereby carrying out denitrification of the water to be treated by making use of the anaerobic ammonia oxidation reaction. In the biological nitrogen removal method, a feed rate of the support (total surface area of the support per unit capacity of the reaction tank) is adjusted so that an amount of nitrous acid produced by the nitrite type nitrification reaction through the action of the nitrite type nitrifying bacteria reaches a level to inhibit a nitrate type nitrification reaction. |
