Shortcut nitrification-denitrification in a sequencing batch reactor by controlling aeration duration based on hydrogen ion production rate online monitoring.
The hydrogen ion production rate (HPR) and the pH of the aeration phase in a sequencing batch reactor (SBR) were simultaneously measured by a novel respirometric-titrimetric instrument. The results showed that HPR could indicate the end of ammonia oxidation with a greater accuracy and sensitivity than pH. An SBR was used to treat synthetic wastewater containing 360 mg/L chemical oxygen demand (COD) and 40 mg/L NH(4+)-N at 20 degrees C with dissolved oxygen (DO) lower than 2.0 mg/L. Controlling the aeration duration based on HPR online monitoring, shortcut nitrification-denitrification was successfully performed for approximately two months with a stable nitrite accumulation rate (NAR) above 88%, and the COD and NH(4+)-N removal ratios were both higher than 90%. Based on the HPR online monitoring data, the estimated NH(4+)-N concentrations in nitrification were closely related to the measured concentrations, with a correlation coefficient of 0.9722, and the estimated values were lower than the measured values mainly because of the titration delay at the beginning of the aeration phase.
Xin
X
Zhang
Daijun
D
Zhang
Qiang
Q
He
Hainan
H
Ai
Peili
P
Lu
D019149:Bioreactors; D058440:Denitrification; D058465:Nitrification; D011522:Protons
D011522:Protons