Ammonium-based aeration control improves nitrogen removal efficiency and reduces N 2 O emissions for partial nitritation-anammox reactors.

Autor: Wan X; BioCo Research Group, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, Ghent, 9000, Belgium., Baeten JE; BioCo Research Group, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, Ghent, 9000, Belgium., Laureni M; BioCo Research Group, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, Ghent, 9000, Belgium; Environmental Biotechnology Group, Delft University of Technology, Mekelweg 5, Delft, CD, 2628, Netherlands., Volcke EIP; BioCo Research Group, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, Ghent, 9000, Belgium. Electronic address: eveline.volcke@ugent.be.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2021 Jul; Vol. 274, pp. 129720. Date of Electronic Publication: 2021 Jan 23.
DOI: 10.1016/j.chemosphere.2021.129720
Abstrakt: This study deals with the effect of aeration control strategies on the nitrogen removal efficiency and nitrous oxide (N 2 O) emissions in a partial nitritation-anammox reactor with granular sludge. More specifically, dissolved oxygen (DO) control, constant airflow and effluent ammonium (NH 4 + ) control strategies were compared through a simulation study. Particular attention was paid to the effect of flocs, which are deliberately or unavoidable present besides granules in this type of reactor. When applying DO control, DO setpoints had to be adjusted to the amount of flocs present in the reactor to maintain high nitrogen removal and reduce N 2 O emissions, which is difficult to realize in practice because of variable floc fractions. Constant airflow rate control could maintain a good nitrogen removal efficiency independent of the floc fraction in the reactor, but failed in N 2 O mitigation. Controlling aeration based on the effluent ammonium concentration results in both high nitrogen removal and relatively low N 2 O emissions, also in the presence of flocs. Fluctuations in floc fractions caused significant upsets in nitrogen removal and N 2 O emissions under DO control but had less effect at constant airflow and effluent ammonium control. Still, rapid and sharp drops in flocs led to a peak in N 2 O emissions at constant airflow and effluent ammonium control. Overall, effluent ammonium control reached the highest average nitrogen removal and lowest N 2 O emissions and consumed the lowest aeration energy under fluctuating floc concentrations.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2021 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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