LAUSR

Abstract. Nitrogen is a dominant nutrient causing eutrophication of water bodies, and the discharge of nitrogen-containing wastewater can bring about undesirable changes to agriculture. Ammonia nitrogen (NH4+-N) is the major form of nitrogen present in wastewater, and the control of NH4+-N discharge in wastewater has been a major concern around the world. Various methods have been adopted to control NH4+-N pollution in accepted water bodies. The methods employed for the elimination of NH4+-N in wastewater can be categorized as physicochemical methods, chemical methods, and biological methods. The objectives of this review are to present a brief introduction to the main approaches for the removal of NH4+-N in wastewater and provide a theoretical basis for practical application of these methods.HighlightsVarious methods of ammonia nitrogen (NH4+-N) removal from wastewater are reviewed.Operating conditions, advantages, and disadvantages of all approaches are discussed.Cost-effective, economical, and environmentally favorable means of NH4+-N removal are proposed. Keywords: Ammonia nitrogen, Biological treatment, Chemical treatment, Physical treatment, Wastewater.