In　this　study,　a　lab-scale　sequencing　batch　reactor　(SBR)　was　established　to　assess　the　feasibility　of　maintaining　partial　nitrification　in　treating　high-ammonium　wastewater　under　the　condition　of　excessive　aeration　(1　L/min,　1289　min).　Results　showed　that　the　average　ammonia　(NH4+-N)　removal　efficiency　(ARE)　was　93.4　±　2.7%　and　the　average　nitrite　accumulation　ratio　(NAR)　was　90.7　±　2.8%　during　15–50　d.　In　a　typical　cycle,　free　ammonia　(FA)　and　free　nitrous　acid　(FNA)　alternately　inhibited　the　activity　of　nitrite　oxidizing　bacteria　(NOB),　while　low　alkalinity　limited　further　nitrification　at　even　excessive　aeration.　Metagenomic　analysis　revealed　that　the　relative　abundance　of　Nitrosomonas,　as　the　ammonia　oxidizing　bacteria　(AOB),　was　up　to　1.61%,　while　NOB　were　not　detected.　Taken　together,　this　study　indicated　partial　nitrification　was　almost　not　affected　by　excessive　aeration,　demonstrating　its　robustness　depending　on　the　cooperative　strategy　of　the　low　alkalinity　limitation　and　the　inhibition　of　FA　and　FNA.　©　2024　Elsevier　Ltd