Abstract:The recovery of phosphorus (Pi) from sewage has become a main direction of sewage reclamation. The polyphosphate-accumulating organisms (PAOs)-biofilm system, which features low carbon source consumption, simple procedure, high efficiency, and sludge reduction, has become a research hotspot in Pi recovery. In this paper, we summarized the basic principles of the system, the functional microorganisms and their metabolisms, and compared the different recovery modes and the performances. In addition, we summed up the research methods and technologies for microorganisms related to the system and their metabolic mechanisms. After describing the status quo of the system in Pi recovery, we proposed the application prospects of this technology, hoping to provide support for the basic research and technological development of PAOs-biofilm system.