In　the　present　study,　anaerobic　ammonium-oxidizing　(anammox)　bacteria　is　immobilized　in　carrier　materials　of　polyethylene　glycol　diacrylate　(PEGDA)　using　N,N,N,＇N＇-tetramethylethylenediamine　(TEMED)　as　the　promoter　and　potassium　persulfate　(KPS)　as　the　initiator,　respectively.　Based　on　orthogonal　experiments,　the　optimal　conditions　of　immobilizing　is　found　to　be　10%　PEGDA　monomer,　0.25%　KPS,　and　0.5%　TEMED　for　polymerizing　at　20　degrees　C　for　approximately　5　min,　with　bacteria　to　gel　ratio　of　1:1.　In　a　continuous-flow　experiment,　the　average　ammonium　and　nitrite　removal　rate　of　immobilized　anammox　granules　with　8　h　hydraulic　detention　time　(HRT)　gradually　increases　after　a　short　period　of　activity　recovery,　and　finally　reaches　91%　for　ammonium　and　83%　for　nitrate.　The　removal　rate　of　ammonium　and　nitrite　is　still　over　50%　(63%　and　55%,　respectively)　as　the　HRT　decreases　to　4　h,　indicating　that　the　immobilized　granules　have　a　strong　resistance　to　nitrogen　shock-loading.　Additionally,　no　granule　crushing　or　suspended　solids　are　observed　in　the　effluent　during　the　100　d　operation,　indicative　of　the　strong　mechanical　properties　of　the　anammox　immobilized　granules.　Notably,　the　content　of　heme　c　in　the　anammox　immobilized　granules　rises　with　a　corresponding　increase　of　nitrogen　removal　rate,　and　reduces　due　to　the　nitrogen　loading　shock.　The　formation　of　channels　inside　the　PEGDA　granules　and　a　large　number　of　anammox　bacteria　filling　the　channels　is　observed　by　scanning　electron　microscopy.　Microbial　community　analysis　using　high-throughput　sequencing　reveals　that　Candidatus　Kuenenia,　the　primary　anammox　bacteria　inside　the　PEGDA　granules,　increases　from　6.58%　to　9.8%　after　the　100　d　run,　indicative　of　superb　biocompatibility　and　substrate　transferring　performance　of　PEGDA　as　a　carrier.