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Sensor‐mediated granular sludge reactor for nitrogen removal and reduced aeration demand using a dilute wastewater
- Source :
- Water Environment Research
- Publication Year :
- 2020
- Publisher :
- John Wiley and Sons Inc., 2020.
-
Abstract
- A sensor‐mediated strategy was applied to a laboratory‐scale granular sludge reactor (GSR) to demonstrate that energy‐efficient inorganic nitrogen removal is possible with a dilute mainstream wastewater. The GSR was fed a dilute wastewater designed to simulate an A‐stage mainstream anaerobic treatment process. DO, pH, and ammonia/nitrate sensors measured water quality as part of a real‐time control strategy that resulted in low‐energy nitrogen removal. At a low COD (0.2 kg m−3 day−1) and ammonia (0.1 kg‐N m−3 day−1) load, the average degree of ammonia oxidation was 86.2 ± 3.2% and total inorganic nitrogen removal was 56.7 ± 2.9% over the entire reactor operation. Aeration was controlled using a DO setpoint, with and without residual ammonia control. Under both strategies, maintaining a low bulk oxygen level (0.5 mg/L) and alternating aerobic/anoxic cycles resulted in a higher level of nitrite accumulation and supported shortcut inorganic nitrogen removal by suppressing nitrite oxidizing bacteria. Furthermore, coupling a DO setpoint aeration strategy with residual ammonia control resulted in more stable nitritation and improved aeration efficiency. The results show that sensor‐mediated controls, especially coupled with a DO setpoint and residual ammonia controls, are beneficial for maintaining stable aerobic granular sludge. Practitioner points Tight sensor‐mediated aeration control is need for better PN/A.Low DO intermittent aeration with minimum ammonium residual results in a stable N removal.Low DO aeration results in a stable NOB suppression.Using sensor‐mediated aeration control in a granular sludge reactor reduces aeration cost.<br />Multiple metabolic pathways and competition for nitrite exist in the treatment of anaerobically pretreated mainstream wastewater using a granular sludge reactor.
- Subjects :
- Nitrogen
02 engineering and technology
010501 environmental sciences
Wastewater
01 natural sciences
Setpoint
chemistry.chemical_compound
Ammonia
Bioreactors
020401 chemical engineering
Nitrate
aeration control
Environmental Chemistry
Ammonium
0204 chemical engineering
Nitrite
Waste Management and Disposal
Research Articles
Nitrites
0105 earth and related environmental sciences
Water Science and Technology
Sewage
Ecological Modeling
NOB suppression
Pulp and paper industry
Pollution
Anoxic waters
chemistry
Denitrification
Aeration
mainstream N removal
Oxidation-Reduction
Research Article
partial nitritation/anammox
Subjects
Details
- Language :
- English
- ISSN :
- 15547531 and 10614303
- Volume :
- 92
- Issue :
- 7
- Database :
- OpenAIRE
- Journal :
- Water Environment Research
- Accession number :
- edsair.doi.dedup.....104889beebbb365b582eaec3ba9aa520