Aerobic　granular　sludge　(AGS)　capable　of　nitrogen　and　phosphorus　removal　is　mainly　limited　to　the　applications　in　sequencing　batch　reactors.　This　study　introduced　an　innovative　continuous　self-circulating　up-flow　fluidized　bed　process　(Zier　process)　using　separate　aeration.　The　process　was　composed　of　an　anoxic　column　(Zier-A),　aeration　column　(Zier-OO)　and　aerobic　column　(Zier-O),　and　was　used　to　treat　actual　municipal　sewage　continuously　for　170　days.　The　process　achieved　self-circulation　of　20–32　times　and　an　up-flow　velocity　within　the　reactor　of　7–16　m/h　which　were　accurately　controlled　with　only　separate　aeration.　The　larger　proportion　of　self-circulating　multiple　times　contributed　to　particle　formation　and　stability,　providing　hydraulic　shear　conditions,　and　screened　the　precipitation　performance　of　the　granular　sludge　(GS).　Meanwhile,　the　dissolved　oxygen　(DO)　of　Zier-O　was　controlled　at　0.1–0.3　mg/L,　and　the　DO　of　Zier-A　input　water　was　zero.　The　accurate　oxygen　supply　enhanced　simultaneous　nitrification　and　denitrification　(SND)　as　well　as　short-cut　nitrification　and　denitrification　in　Zier-O　and　improved　the　COD　utilization　rate　and　the　nitrogen　removal　rate　in　Zier-A.　The　COD　treatment　capacity　reached　2.46　kg-COD/(m³·d).　With　a　hydraulic　retention　time　of　10　h,　the　process　consistently　ensured　that　the　average　concentrations　of　ammonia　nitrogen　and　total　nitrogen　in　the　effluent　were　maintained　below　5　and　15　mg/L,　respectively.　Moreover,　the　process　maintained　the　shape　and　stability　of　GS,　the　median　diameter　of　GS　ranged　between　300–1210　μm,　the　percentage　of　mass　with　particle　size　distribution　＜　200　μm　at　a　height　of　150　cm　within　Zier-A　and　Zier-O　accounted　for　as　low　as　0.04%–0.05%,　and　showed　good　settling　performance.　The　suspended　solids　in　effluent　can　be　maintained　at　50–80　mg/L.　Overall,　the　unique　structural　setting　and　control　method　of　the　Zier　process　provide　another　approach　for　the　application　of　continuous　AGS　treatment　for　municipal　sewage.　©　2024　Elsevier　Ltd