Bioresource Technology 334 (2021) 125240 Available online 28 April 2021 0960-8524/© 2021 Elsevier Ltd. All rights reserved. Review Anammox bacteria in treating ammonium rich wastewater: Recent perspective and appraisal Chanusha Weralupitiya a, b , Rasika Wanigatunge b , Sarangi Joseph c , Bandunee C.L. Athapattu c , Tae-Ho Lee d , Jayanta Kumar Biswas e , Maneesha P. Ginige f , Su Shiung Lam g , P. Senthil Kumar h , Meththika Vithanage a, * a Ecosphere Resilience Research Centre, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka b Department of Plant and Molecular Biology, University of Kelaniya, Kelaniya, Sri Lanka c Department of Civil Engineering, The Open University of Sri Lanka, Nawala, Sri Lanka d Department of Civil and Environmental Engineering, Pusan National University, Busan, South Korea e Department of Ecological Studies, and International Centre for Ecological Engineering, University of Kalyani, Kalyani, Nadia 741235, West Bengal, India f CSIRO Land and Water, Floreat, Western Australia 6014, Australia g Pyrolysis Technology Research Group, Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia h Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Chennai 603110, India HIGHLIGHTS G R A P H I C A L ABSTRACT • Metabolism, inhibition conditions, application of anammox bacteria are discussed. • Anammox process is a successful ven- ture in treatment of ammonia in wastewater. • Effciency of anammox process is deter- mined by the operational conditions. A R T I C L E INFO Keywords: Anammox bacteria Ammonia rich wastewater Growth and metabolism Applications Inhibitory factors ABSTRACT The discovery of anammox process has provided eco-friendly and low-cost means of treating ammonia rich wastewater with remarkable effciency. Furthermore, recent studies have shown that the possibility of operating the anammox process under low temperatures and high organic matter contents broadening the application of the anammox process. However, short doubling time and extensive levels of sensitivity towards nutrients and environmental alterations such as salinity and temperature are the limitations in practical applications of the anammox process. This review article provides the recent yet comprehensive viewpoint on anammox bacteria and the key perspectives in applying them as an effcient strategy for wastewater treatment. * Corresponding author. E-mail address: meththika@sjp.ac.lk (M. Vithanage). Contents lists available at ScienceDirect Bioresource Technology journal homepage: www.elsevier.com/locate/biortech https://doi.org/10.1016/j.biortech.2021.125240 Received 4 March 2021; Received in revised form 23 April 2021; Accepted 25 April 2021