In　this　study,　hollow　fiber　membranes　in　Anoxic-Oxic　Membrane　Bioreactor　(A/O-MBR)　were　modified　using　dopamine　(DA)　to　crosslink　carbon　nanotubes　(CNTs),　referred　as　M-CNTs/PDA,　and　their　fouling　behavior　was　compared　with　original　membranes　(M-pristine).　The　experimental　results　indicated　the　total　nitrogen　removal　rates　kept　exceeding　90　%.　Transmembrane　Pressure　(TMP)　data　revealed　that　M-CNTs/PDA　exhibits　an　extended　operational　lifespan　than　the　M-pristine.　Lower　levels　concentration　of　protein,　polysaccharides　and　humic　substances　presented　on　the　foulant　layer　of　M-CNTs/PDA　membranes.　In　filtration　experiments,　M-CNTs/PDA　exhibited　a　smaller　reduction　in　specific　flux　and　higher　fouling　reversibility,　with　a　flux　recovery　rate　of　96.64　%.　The　confocal　laser　scanning　microscopy　(CLSM)　images　further　indicated　that　the　fouling　layer　on　the　M-CNTs/PDA　is　significantly　thinner.　Flow　cytometry　analyses　indicated　that　M-CNTs/PDA　has　sterilizing　effects　that　can　effectively　mitigate　biological　fouling　to　some　extent.　Overall,　the　M-CNTs/PDA　membrane　effectively　mitigated　both　organic　and　biological　fouling.　This　offers　a　promising　strategy　to　enhance　membrane　performance　and　longevity　in　A/O-MBR　systems,　addressing　a　critical　challenge　in　wastewater　treatment　by　improving　operational　efficiency　and　reducing　maintenance　costs.　©　2025　Elsevier　Ltd