Abstract
The effects of fluctuating organic carbon to nitrogen (C/N) ratios on mainstream simultaneous partial nitrification, anammox, and denitrification (SNAD) process were studied over 376-day period. The nitrogen removal efficiency decreased from 85.0 ± 6.6 % to 75.8 ± 2.8 % as C/N ratio decreased (3.4 → 1.7), but increased to 82.0 ± 1.9 % when C/N ratio raised to 2.9 and to 78.4 ± 3.0 % when C/N ratio decreased again (2.9 → 2.1), indicating that high C/N ratios promoted nitrogen removal. As C/N ratio raised (1.7 → 2.9), anaerobic ammonia-oxidizing bacteria (AnAOB) abundance increased from 1.3 × 109 to 2.0 × 109 copies/L, which explained the improved nitrogen removal. With an elevated C/N ratio, partial nitrification and endogenous partial denitrification reactions were enhanced, providing more nitrite for AnAOB. Additionally, the aerobic_chemoheterotrophy function and particle sizes increased, forming more stable anoxic microenvironment for AnAOB. Overall, increasing C/N ratio promoted the stability of mainstream SNAD.
Original language | English |
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Article number | 130169 |
Journal | Bioresource Technology |
Volume | 393 |
DOIs | |
State | Published - 1 Feb 2024 |
Keywords
- Endogenous partial denitrification
- Evolution of microbial community
- Integrated fixed-film activated sludge
- Sewage
- Simultaneous partial nitrification, anammox, and denitrification
ASJC Scopus subject areas
- Bioengineering
- Environmental Engineering
- Renewable Energy, Sustainability and the Environment
- Waste Management and Disposal