Biomineralization　inspired　the　development　of　simultaneousbiologicaltransformations　and　chemical　precipitation　for　simultaneous　nitrogenremoval　and　phosphorus　recovery　from　wastewater,　which　could　compensatefor　the　incapacity　of　phosphorus　management　in　the　new　biologicalroute　of　anaerobic　ammonium　oxidation　(anammox).　In　this　study,　westrengthened　anammox-mediated　biomineralization　by　long-term　feedingof　concentrated　N,　P,　and　Ca　substrates,　and　a　self-assembled　matrixof　anammox　bacteria　and　hydroxyapatite　(HAP)　was　fabricated　in　a　granularshape,　defined　as　HAP-anammox　granules.　HAP　was　identified　as　thedominant　mineral　using　elemental　analysis,　X-ray　diffraction,　andRaman　spectroscopy.　The　intensive　precipitation　of　HAP　resulted　ina　higher　inorganic　fraction　and　substantially　improved　settleabilityof　anammox　biomass,　which　facilitated　HAP　precipitation　by　actingas　nucleation　and　metabolically　elevated　pH.　By　using　X-ray　microcomputedtomography,　we　visually　represented　the　hybrid　texture　of　interwovenHAP　pellets　and　biomass,　the　core-shell　layered　architectureof　different-sized　HAP-anammox　granules,　and　their　homogeneously　regulatedthickness　of　the　outer　biofilm　(from　118　to　635　&　mu;m).　This　uniquearchitecture　endows　HAP-anammox　granules　with　outstanding　settleability,active　biofilm,　and　tightly　bonded　biofilm　with　the　carrier,　whichmay　explain　the　excellent　performance　of　these　HAP-anammox　granulesunder　various　challenging　operational　conditions　in　previous　studies.　This　study　demonstrates　the　unique　characteristicsand　3Dhierarchy　of　HAP-anammox　granules.