Removal of Ammonia Nitrogen from Wastewater: A Review

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 (NH 4 + -N) is the major form of nitrogen present in wastewater, and the control of NH 4 + -N discharge in wastewater has been a major concern around the world. Various methods have been adopted to control NH 4 + -N pollution in accepted water bodies. The methods employed for the elimination of NH 4 + -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 NH 4 + -N in wastewater and provide a theoretical basis for practical application of these methods. Highlights Various methods of ammonia nitrogen (NH 4 + -N) removal from wastewater are reviewed. Operating conditions, advantages, and disadvantages of all approaches are discussed. Cost-effective, economical, and environmentally favorable means of NH 4 + -N removal are proposed.