The effect of nitrite on aerobic phosphate uptake and denitrifying activity of phosphate-accumulating organisms.
An anaerobic/aerobic/anoxic/aerobic sequencing batch reactor (SBR) was operated with municipal wastewater to investigate the effect of nitrite on biological phosphorus removal (BPR). When nitrite accumulated, aerobic phosphate uptake activity significantly decreased and, in case of hard exposure to nitrite, BPR severely deteriorated. The interesting observation was that the relative anoxic activity of phosphate accumulating organisms (PAOs) increased after nitrite exposure. Moreover batch tests of aerobic phosphate uptake in the presence/absence of nitrite indicated that PAOs with the higher relative anoxic activity are less sensitive to nitrite exposure. From these results, we concluded that BPR is sensitive to nitrite exposure, but BPR containing PAOs with the higher relative anoxic activity is possibly more stable against nitrite than BPR containing PAOs with the lower relative anoxic activity.
Yoshida
Y
Y
Department of Civil Engineering, Graduate School of Science and Technology, Nihon University, 1-8-14, Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8308, Japan. y_yuki9@hotmail.com
Takahashi
K
K
Saito
T
T
Tanaka
K
K
D001421:Bacteria, Anaerobic / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors; D009573:Nitrites / Q000737:chemistry*; D009584:Nitrogen; D010710:Phosphates / Q000737:chemistry*; D010758:Phosphorus; D011122:Polyphosphates / Q000737:chemistry; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
D009573:Nitrites; D010710:Phosphates; D011122:Polyphosphates; D012722:Sewage; D010758:Phosphorus; D009584:Nitrogen