Nitrogen-containing wastewater denitrification method and denitrification apparatus

摘要

Provided are a denitrification method and denitrification apparatus for nitrogen-containing waste water for which size reduction of the treatment apparatus is possible and with which partial conversion to nitrous acid and anaerobic oxidation can be performed stably and efficiently in the same reaction tank. The denitrification method for nitrogen-containing waste water comprises: a step (S11) for feeding nitrogen-containing waste water into a reaction tank in which a microbe carrier containing an ammonia-oxidizing microbe and an anaerobic ammonia-oxidizing microbe or a microbe carrier and activated sludge are held; steps (S12, S13) for feeding oxygen-containing gas or a gas that does not contain oxygen into the reaction tank in sequence and stirring the nitrogen-containing waste water in the reaction tank to denitrify the nitrogen-containing waste water by the action of the ammonia-oxidizing microbe and anaerobic ammonia-oxidizing microbe; and steps (S14, S15) for separating the microbe carrier or microbe carrier and activated sludge from the treated water and discharging the treated water from the reaction tank.