Recent advances in biological nitrogen removal through anammox process - Bibliometric analysis and integrated technologies

Anammox process offers an eco-friendly and green technology for nitrogen removal from wastewater. This study analysed research trends in anammox technology using a bibliometric analysis of articles published between 2013 and 2025. The analysis revealed a notable rise in attention to integration with novel technologies like comammox, sulfammox, feammox, n-DAMO etc suggesting a focus on improving the process. China dominated anammox research with 60% of publications, suggesting global collaboration led by China. The analysis also identified key research areas like optimizing anammox integration with other processes, understanding microbial communities, and the role of EPS in improving efficiency. Notably, the anammox process has been successfully implemented across a variety of reactor configurations, including SBRs, MBBRs, UASB, CWs, IFAS and hybrid reactors demonstrating its versatility across diverse wastewater treatment applications. This review comprehensively summarizes the current landscape of the anammox process, highlighting recent technological advancements and exploring future directions for improved engineering applications. These directions include cost-effective inoculum sources enriched from wastewater treatment plant sludge or natural environments, advanced reactor designs, and real-time monitoring, which can further optimize anammox for self-sufficient wastewater treatment.