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High Nitrite Buildup During Nitrification in a Rotating Disk Reactor
Author(s) -
Antileo Christian,
Roeckel Marlene,
Wiesmann Udo
Publication year - 2003
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143003x140935
Subject(s) - nitrite , continuous stirred tank reactor , nitrification , aeration , chemistry , bioreactor , oxygen , washout , denitrification , environmental engineering , nitrate , environmental chemistry , nitrogen , environmental science , organic chemistry , oceanography , geology
Incomplete nitrification with high nitrite accumulation has three practical advantages: lower oxygen consumption, less need for organics for denitrification, and lower sludge production during denitrification. Nitrification leading to high nitrite formation was experimentally studied in a continuous single rotating disk reactor (RDR) and compared to a modeled continuous completely stirred tank reactor (CSTR). The results of this model show that to accumulate nitrite greater than 50% at oxygen levels higher than 3.5 mg O 2 /L, pH levels higher than 8.5 and 9.0 are required for a CSTR with and without cell washout, respectively. For a CSTR without cell washout at pH 7 and 1 mg O 2 /L, it was predicted that a nitrite accumulation less than 5% could be reached. Conversely, for a partially submerged continuous RDR without any additional aeration supply (already at pH 7 and 1.3 mg O 2 /L), high nitrite accumulation (more than 75%) was achieved and the influence of pH from 7 to 9 was not significant. This difference is believed to be caused by mass transfer. In addition, nitrification was observed to occur under oxygen transport limitation for a totally submerged continuous RDR.