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Lookup NU author(s): Professor Thomas CurtisORCiD
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND).
© 2021 Elsevier Ltd. The design of wastewater treatment plants in the tropics is largely based on default parameters from the studies in temperate climates. This may lead to suboptimal design, such as the intensive aeration required for biological nitrogen removal. To reduce the aeration energy, a low-dissolved‑oxygen oxic-anoxic (low-DO OA) process was developed for treating low chemical oxygen demand-to‑nitrogen (COD/N) tropical wastewater. This study calibrated the growth kinetic parameters of microbes in a conventional anoxic-oxic (AO) and a low-DO OA sequencing batch reactors (SBRs) based on a modified version of Activated Sludge Model No. 1 (ASM1). We selected three parameters to be calibrated, namely the maximum growth rate of heterotrophs (μH), maximum growth rate of nitrifiers (μA) and nitrifiers' affinity towards ammoniacal nitrogen (NH4+−N) (KNH). The low-DO OA SBR selected for microbes with a low μH (2.2 d−1), μA (1.49 d−1) and KNH (0.035 mgNH4+−NL−1), which supported the observed proliferation of K-strategist Nitrospira at low-DO condition (0.4 ± 0.2 mg O2 L−1). The calibrated parameters for the AO SBR (1.7 ± 0.2 mg O2 L−1) were significantly higher (μH=9.3 d−1, μA=4.49 d−1, KNH=6.3 mgNH4+−NL−1) than the low-DO OA SBR. The calibrated ASM1 adequately simulated the low-DO OA SBR performance under different sludge retention times. The findings demonstrated a kinetic insight into the unique K-strategist nitrifiers in a low-DO OA process. Moreover, this study reinforced the importance of using parameters for tropical wastewater rather than relying on default values from studies in temperate climates.
Author(s): How SW, Shoji T, Tan CK, Curtis TP, Chua ASM
Publication type: Article
Publication status: Published
Journal: Journal of Water Process Engineering
Year: 2021
Volume: 43
Print publication date: 01/10/2021
Online publication date: 03/08/2021
Acceptance date: 20/07/2021
Date deposited: 07/10/2021
ISSN (print): 2214-7144
Publisher: Elsevier Ltd
URL: https://doi.org/10.1016/j.jwpe.2021.102235
DOI: 10.1016/j.jwpe.2021.102235
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