BIOLOGICAL TREATMENT OF AMMONIA NITROGEN

• Main Authors: NAKAMURA HIRONORI, OGASAWARA TAKAKO
• Format: Patent
• Language: English
• Published: 29.02.2000
• Edition: 7
• Subjects: CHEMISTRY; METALLURGY; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

PROBLEM TO BE SOLVED: To stably and effectively perform nitrification reaction of nitrous acid type by biologically treating ammonia nitrogen. SOLUTION: A biological reactor 14 is constituted of a nitrification tank consisting of two tanks a first stage nitrification tank 24 and a second stage nitrification tank 26, a denitrification tank consisting of two tanks, a first stage denitrification tank 28 and a second denitrification tank 30, and one aerobic tank 32. In this way, the load quantity of ammonia nitrogen per the first stage nitrification tank 24 is kept at 1.5-2.5 kg-N/m3.day, and the concentration of ammonia nitrogen in the first stage nitrification tank 24 is kept at 250-550 mg/L, thereby enabling to dominantly perform nitrification reaction of nitrous acid type be stopping nitrification reaction in the stage of nitrous acid nitrogen which is an intermediate product for oxidizing ammonia nitrogen to nitric acid nitrogen. Therefore, since the nitrification reaction of nitrous acid type can be stably performed, the time required for the nitrification reaction can be shortened, and also the aeration quantity of air for forming aerobic conditions can be reduced.