Combined　partial　nitrification-denitrification/anammox　(PN-PD/A)　processes　have　attracted　great　attention　from　researchers　in　recent　years　to　achieve　high　nitrogen　removal　from　low　carbon　/nitrogen　(C/N)　municipal　wastewater.　In　this　context,　a　step-feed　anoxic/oxic　(A/O)　process　was　conducted　in　this　study　through　the　combination　of　the　partial　nitrification-anammox　(PN/A)　and　partial　denitrification-anammox　(PD/A)　to　remove　N　from　municipal　wastewater　with　low　C/N.　The　enhancement　of　the　PN-PD/A　process　resulted　in　N　removal　efficiency　of　85.6%　at　C/N　of　2.8.　The　contributions　of　the　anammox　reached　36.4　and　8.8%　in　the　anoxic　and　oxic　chambers,　respectively.　The　biocarriers　added　to　the　anoxic　and　oxic　chambers　increased　the　relative　abundance　of　the　anammox　bacteria　in　biofilms　from　0.61%　to　1.51%　and　1.02%,　respectively.　This　study　demonstrated　that　employing　the　step-feed　A/O　process　can　create　optimal　conditions　for　the　anammox　bacteria　growth,　thereby　ensuring　advanced　N　removal　from　low　C/N　municipal　wastewater.　©　2023　Elsevier　Ltd