In　this　work,　a　bioprocess　model　was　applied　to　first　determine　the　impacts　of　influent　substrates　conditions　on　the　granular　bioreactor　performing　nitrate/nitrite-dependent　anaerobic　methane　oxidation　(n-DAMO)　and　anammox　integrated　processes　and　then　investigate　the　roles　of　granular　sludge　properties　in　regulating　the　bioreactor　performance　and　start-up　process.　The　ideal　influent　substrates　conditions　were　identified　at　NO2−-N/NH4+-N　of　1:1　and　dissolved　CH4　concentration　of　85　g　COD　m−3,　which　achieved　98.6%　total　nitrogen　removal　and　87.7%　dissolved　CH4　utilization.　Under　such　ideal　influent　conditions,　the　initial　properties　of　granular　sludge　didn＇t　significantly　affect　the　granular　bioreactor　performance.　However,　inoculation　of　granular　sludge　with　a　relatively　small　granular　sludge　size　and　a　high　abundance　of　n-DAMO　archaea　or/and　anammox　bacteria　could　effectively　shorten　the　bioreactor　start-up.　Meanwhile,　reducing　the　diffusivity　of　solutes　within　granular　sludge　was　also　beneficial　for　expediting　the　start-up　process　and　promoting　dissolved　CH4　utilization.　©　2023　Elsevier　Ltd