Partial　nitrification　(PN),　is　a　promising　nitrogen　removal　technology　in　wastewater　treatment.　Contrary　to　the　dogma　that　low　dissolved　oxygen　(DO)　is　more　conducive　to　achieving　PN,　this　study　successfully　established　PN　within　7　days　under　high　DO　conditions　(＞　6　mg/L).　Ultra-stable　PN　was　maintained　over　143　days　with　an　average　nitrite　accumulation　ratio　of　98　%　treating　real　domestic　wastewater.　Kinetics　indicated　that　the　maximum　activity　difference　increased　to　40　folds　between　ammonia　oxidizing　bacteria　(AOB)　and　nitrite　oxidizing　bacterium　(NOB),　resulting　in　AOB　prospering　while　NOB　declined.　High　DO　operation　reshaped　the　nitrifier　community　with　AOB　genera　relative　abundance　increased　substantially　(0.1　%-1.2　%),　while　the　predominant　NOB　Nitrospira　was　below　the　detection　limit.　Batch　test　confirmed　the　reproducibility　of　this　strategy　to　achieve　PN　using　ordinary　activated　sludge.　This　study　provides　an　update　on　developing　a　feasible　approach　for　the　rapid　realization　and　stable　maintenance　of　mainstream　PN.　©　2024