Leong, Chew Lee and How, Seow Wah and Rabuni, Mohamad Fairus and Aris, Alijah Mohd and Khor, Bee Chin and Curtis, Thomas P. and Chua, Adeline Seak May (2023) Pilot Study of Oxic-Anoxic Process under Low Dissolved Oxygen for Nitrogen Removal from Low COD/N Tropical Wastewater. Water, 15 (11). ISSN 2073-4441, DOI https://doi.org/10.3390/w15112070.
Full text not available from this repository.Abstract
Conventionally, nitrification in biological nitrogen removal (BNR) requires high dissolved oxygen (DO) concentrations (>2 mg L-1), making the process energy intensive. Recent studies have shown that efficient ammonium removal and energy reduction can be realized by operating the nitrification at low DO concentrations (<1 mg L-1). In this study, the low-DO oxic anoxic (low-DO OA) process was operated in a pilot-scale sequencing batch reactor (SBR) over 218 days to evaluate the feasibility of nitrogen removal from low chemical oxygen demand-to-nitrogen ratio (COD/N) tropical municipal wastewater. The results revealed that the low-DO OA process attained high removal efficiency for ammonium (97%) and total nitrogen (TN) (80%) under an average DO concentration of 0.6 mg L-1. The effective TN removal efficiency is attributed to the occurrence of simultaneous nitrification-denitrification (SND) under low DO conditions. Further batch tests revealed that slowly biodegradable COD (sbCOD) in tropical wastewater can support denitrification in the post-anoxic phase, resulting in a high TN removal rate. Compared with high DO concentrations (2 mg L-1), low DO conditions achieved 10% higher TN removal efficiency, with similar ammonium and COD removal efficiency. This study is crucial in promoting the energy efficiency and sustainability of wastewater treatment plants treating low COD/N wastewater.
| Item Type: | Article |
|---|---|
| Funders: | Ministry of Higher Education, Malaysia under the Fundamental Research Grant Scheme (FRGS/1/2020/TK0/UM/02/26), Newton Fund Impact Scheme (536710788/IF024-2020) |
| Uncontrolled Keywords: | activated sludge; biological nitrogen removal; municipal wastewater; nitrification; denitrification |
| Subjects: | T Technology > TD Environmental technology. Sanitary engineering T Technology > TP Chemical technology |
| Divisions: | Faculty of Engineering > Department of Chemical Engineering |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 01 Oct 2025 03:40 |
| Last Modified: | 01 Oct 2025 03:40 |
| URI: | http://eprints.um.edu.my/id/eprint/50288 |
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