Technical analysis of biological methods for ammonia nitrogen removal from wastewater

Water pollution represents a critical global environmental challenge. Elevated nitrogen concentrations in aquatic systems can trigger eutrophication, a process that degrades water quality and poses significant risks to human health and safety. Consequently, governments worldwide have established stringent standards for discharging nitrogen-rich wastewater. Biological nitrogen removal is the most widely adopted treatment approach globally. However, each specific biological technology possesses inherent limitations. This review synthesizes current international research on biological nitrogen removal. We examine the underlying principles, practical applications, and recent advancements of various technologies, providing a comprehensive analysis of the advantages and disadvantages of nitrification, denitrification, and anaerobic ammonium oxidation. This analysis offers a scientifically-grounded perspective on the present state and future trajectory of biological wastewater treatment for nitrogen removal.