Advancements in entrapment immobilization technology for enhancing Anammox process: Material effects, preparation strategy and application.

Entrapment immobilization technology is a highly efficient and promising strategy for biological wastewater treatment, offering high biomass retention, strong resistance to shock loads, and excellent operational stability. This method effectively addresses key challenges associated with the slow growth rate and environmental sensitivity of anaerobic ammonium-oxidizing bacteria (AnAOB). This review provides a comprehensive overview of recent advancements in entrapment carriers for the Anammox process, with an emphasis on the pivotal role of carbon-based and iron-based materials in enhancing mechanical strength and promoting AnAOB activity. Additionally, this review provides a detailed analysis of how cross-linking mechanisms and entrapment form designs influence microbial activity and overall system efficiency. Finally, the review summarizes the applications of entrapment immobilization technology in the Anammox process, highlighting its role in promoting synergistic interactions between AnAOB and other microorganisms to enhance nitrogen removal efficiency, accelerate process start-up, and inform future development directions.