N-removal performance and underlying bacterial taxa of upflow filter bioreactor system under different dissolved oxygen and internal recycle conditions.
Biological N-removal treatment of piggery wastewater in the upflow anaerobic-anoxic-aerobic floating filter (UA(3)FF) bioreactor based on the concept of nitritation-denitritation was studied along with the changes in internal recycle ratio and dissolved oxygen concentration (DO). Consecutive changes in the recirculation ratio between the anoxic and aerobic reactors has resulted in abundance and composition shifts of N-cycling bacteria as well as other bacterial groups, reflecting different survival strategies across (bio/physico)chemical milieu. The DO concentration was optimized to achieve nitritation in the aerobic reactor and denitritation in the anoxic reactor. Optimal nitritation-denitritation (270 and 130 g NO(2) (-)-N produced or reduced/m(3) filter media/day) was obtained at DO of 1.0-1.5 mg/l, inter-reactor recirculation ratio of 1:1-2:1, HRT of 24 h, pH of 7.6 +/- 0.3, and temperature of 28 +/- 4 degrees C. Since only well known nitrifying and denitrifying taxa were found, nitritation-denitritation was likely carried out by these bacteria rather than the yet unidentified novel taxa. Archaeal nitrifiers recently discovered to be important in the global N-cycle were not detected.
Laobusnanant
Prasert
P
Environmental Engineering and Management, Asian Institute of Technology, Klong Luang, Pathumthani 12120, Thailand.
Lee
Seung Hwan
SH
Anceno
Alfredo J
AJ
Ghosh
Gopal C
GC
Kim
Dong Jin
DJ
Pathak
Bipin K
BK
Shipin
Oleg V
OV
D000332:Aerobiosis; D000693:Anaerobiosis; D000818:Animals; D020562:Betaproteobacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001698:Biomedical Engineering; D019149:Bioreactors / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004867:Equipment Design; D017404:In Situ Hybridization, Fluorescence; D017744:Medical Waste Disposal; D009584:Nitrogen / Q000302:isolation & purification* / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D034421:Sus scrofa; D014865:Waste Disposal, Fluid
D004269:DNA, Bacterial; D017744:Medical Waste Disposal; D009584:Nitrogen; D010100:Oxygen