Optimization of free ammonia concentration for nitrite accumulation in shortcut biological nitrogen removal process.
A shortcut biological nitrogen removal (SBNR) utilizes the concept of a direct conversion of ammonium to nitrite and then to nitrogen gas. A successful SBNR requires accumulation of nitrite in the system and inhibition of the activity of nitrite oxidizers. A high concentration of free ammonia (FA) inhibits nitrite oxidizers, but unfortunately decreases the ammonium removal rate as well. Therefore, the optimal range of FA concentration is necessary not only to stabilize nitrite accumulation but also to achieve maximum ammonium removal. In order to derive such optimal FA concentrations, the specific substrate utilization rates of ammonium and nitrite oxidizers were measured. The optimal FA concentration range appeared to be 5-10 mg/L for the adapted sludge. The simulated results from the modified inhibition model expressed by FA and ammonium/nitrite concentrations were shown very similar to the experimental results.
Chung
Jinwook
J
Center for Environmental Biotechnology, Biodesign Institute at Arizona State University, 2001 South McAllister Avenue, Tempe, AZ, 85287-5801, USA. jinwook.chung@asu.edu
Shim
Hojae
H
Park
Seong-Jun
SJ
Kim
Seung-Jin
SJ
Bae
Wookeun
W
D000641:Ammonia / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D003198:Computer Simulation; D008954:Models, Biological; D009573:Nitrites / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*; D014873:Water Pollutants / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*
D009573:Nitrites; D012722:Sewage; D014873:Water Pollutants; D000641:Ammonia