Coupling Partial Nitritation, Anammox and n-DAMO in a membrane aerated biofilm reactor for simultaneous dissolved methane and nitrogen removal

Yan Lu; Tao Liu; Shihu Hu; Zhiguo Yuan; Jason Dwyer; Ben Van Den Akker; James Lloyd; Jianhua Guo

doi:10.1016/j.watres.2024.121511

Coupling Partial Nitritation, Anammox and n-DAMO in a membrane aerated biofilm reactor for simultaneous dissolved methane and nitrogen removal

Water Res. 2024 May 15:255:121511. doi: 10.1016/j.watres.2024.121511. Epub 2024 Mar 24.

Authors

Yan Lu¹, Tao Liu², Shihu Hu¹, Zhiguo Yuan³, Jason Dwyer⁴, Ben Van Den Akker⁵, James Lloyd⁶, Jianhua Guo⁷

Affiliations

¹ Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), the University of Queensland, St. Lucia, Queensland 4072, Australia.
² Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), the University of Queensland, St. Lucia, Queensland 4072, Australia. Electronic address: uqtliu8@uq.edu.au.
³ School of Energy and Environment, City University of Hong Kong, Hong Kong SAR, China.
⁴ Urban Utilities, Brisbane, QLD 4000, Australia.
⁵ South Australian Water Corporation, 250 Victoria Square, Adelaide, SA 5000, Australia; STEM, University of South Australia, Mawson Lakes, South Australia 5095, Australia.
⁶ Melbourne Water, 990 La Trobe St, Docklands, VIC 3000, Australia.
⁷ Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), the University of Queensland, St. Lucia, Queensland 4072, Australia. Electronic address: jianhua.guo@uq.edu.au.

PMID: 38552483
DOI: 10.1016/j.watres.2024.121511

Abstract

Anaerobic technologies with downstream autotrophic nitrogen removal have been proposed to enhance bioenergy recovery and transform a wastewater treatment plant from an energy consumer to an energy exporter. However, approximately 20-50 % of the produced methane is dissolved in the anaerobically treated effluent and is easily stripped into the atmosphere in the downstream aerobic process, contributing to the release of greenhouse gas emissions. This study aims to develop a solution to beneficially utilize dissolved methane to support high-level nitrogen removal from anaerobically treated mainstream wastewater. A novel technology, integrating Partial Nitritation, Anammox and Methane-dependent nitrite/nitrate reduction (i.e. PNAM) was demonstrated in a membrane-aerated biofilm reactor (MABR). With the feeding of ∼50 mg NH₄⁺-N/L and ∼20 mg/L dissolved methane at a hydraulic retention time of 15 h, around 90 % of nitrogen and ∼100 % of dissolved methane can be removed together in the MABR. Microbial community characterization revealed that ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB), anammox bacteria, nitrite/nitrate-dependent anaerobic methane oxidation microorganisms (n-DAMO bacteria and archaea) and aerobic methanotrophs co-existed in the established biofilm. Batch tests confirmed the active microbial pathways and showed that AOB, anammox bacteria and n-DAMO microbes were jointly responsible for the nitrogen removal, and dissolved methane was mainly removed by the n-DAMO process, with aerobic methane oxidation making a minor contribution. In addition, the established system was robust against dynamic changes in influent composition. The study provides a promising technology for the simultaneous removal of dissolved methane and nitrogen from domestic wastewater, which can support the transformation of wastewater treatment from an energy- and carbon-intensive process, to one that is energy- and carbon-neutral.

Keywords: Anaerobic wastewater treatment; Anammox; Dissolved methane; Membrane aerated biofilm reactor (MABR); Nitrite/nitrate-dependent anaerobic methane oxidation (n-DAMO).