Effective　retention　of　anammox　bacteria　(AnAOB)　is　the　prerequisite　for　the　application　of　anammox　process,　especially　in　treating　low-strength　wastewater.　The　employment　of　anammox　granules　coupled　with　phosphorus　minerals　has　gained　extensive　attention　as　retaining　biomass.　To　achieve　the　stability　of　mineralized　anammox　system　for　low-strength　wastewater　treatment,　two　switching　strategies　(cascade　strategy　and　plunging　strategy)　were　compared　in　terms　of　nitrogen　removal　performance,　physicochemical　properties　and　microbial　community.　Results　showed　cascade　strategy　significantly　implemented　the　nitrogen　removal　rate　of　0.86　±　0.05　kg　N/m3/d　at　hydraulic　retention　time　of　1.6　h,　with　higher　phosphorus　removal　via　the　hydroxyapatite　formation.　The　cross-section　observation　indicated　mineralized　anammox　granules　exhibited　a　unique　spatially　heterogeneous　structure　with　distinct　zoning.　Moreover,　the　granules　displayed　dense　structure,　excellent　settleability,　superior　mechanical　strength　and　outstanding　biomass　retention　based　on　cascade　strategy.　Microbial　analysis　revealed　the　dominant　populations　were　shifted　from　Ca.　Kuenenia　to　Ca.　Brocadia　after　switching　to　low-strength　conditions.　Further　investigation　is　warranted　to　explore　effective　methods　for　phosphorus　recovery　from　hydroxyapatite.　Overall,　the　study　provided　a　reference　for　promoting　and　understanding　the　synergistic　nitrogen　removal　and　phosphorus　recovery　in　actual　applications.　©　2024