Abstract
An integrated partial nitritation/anammox (PN/A) coupled with enhanced biological phosphorus removal process (EBPR) has been developed to decrease carbon source consumption and energy consumption, as well as improve nitrogen and phosphorus removal efficiency, in response to the problems of energy consumption, high drug consumption, and low efficiency in nitrogen and phosphorus removal of low C/N municipal wastewater due to insufficient carbon source. The operation efficiency of the integrated process was investigated by stablishing a mixed system comprising suspended sludge and biofilm and employing anaerobic-aerobic operation mode and intermittent aeration strategy. The results showed that the reactor operated stably in a long term, with a total inorganic nitrogen (TIN) concentration lower than 4 mg·L-1 and a phosphorus concentration of 0.2 mg·L-1 in the effluent. The average TIN removal efficiency was above 90%, the average P removal rate was over 85%, and the average nitrogen removal rate was 53 mg·(gVSS·d)-1. With enhanced intermittent aeration, nitrite oxidation bacteria (NOB) can be well suppressed in the system and the rate of nitrite nitrogen accumulation reached up to 60% or even 100%. After adopting a tight aerobic sludge age (3.5 days) control for suspended sludge, NOB started to move from suspended sludge to biofilm, however, the accumulation rate of nitrite was unaffected due to the restriction of biofilm mass transfer. The specific anaerobic ammonia oxidation activity in this system has increased by 5 times. Candidatus Brocadia was the dominant anaerobic ammonia oxidizing bacteria genus with a relative abundance of 1.1%, which is 2.75 times greater than under mainstream conditions. This work demonstrated the feasibility of cooperation of PN/A and EBPR for low C/N municipal wastewater treatment. This process has a good ability to cope with quality fluctuations and ensures a stable operation.
Translated title of the contribution | Integrated PN/A and EBPR process for real low C/N mainstream municipal wastewater treatment |
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Original language | Chinese (Traditional) |
Pages (from-to) | 2458-2467 |
Number of pages | 10 |
Journal | Chinese Journal of Environmental Engineering |
Volume | 17 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2023 |
Keywords
- anammox
- carbon
- dual-SRT
- enhanced biological phosphorus removal
- partial nitritation
- pollution reduction
- simultaneous nitrogen and phosphorus removal
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Water Science and Technology
- Waste Management and Disposal
- Pollution