This　study　innovated　constructed　an　activated　carbon-loaded　nano-zero-valent　iron　(nZVI-C)　enhanced　membrane　aerated　biofilm　reactor　(MABR)　coupled　partial　nitritation/anammox　(PN/A)　system　for　optimizing　nitrogen　and　antibiotics　removal.　Results　showed　that　nitrogen　and　antibiotic　removal　efficiencies　of　88.45　+/-　0.14%　and　89.90　+/-　3.07%　were　obtained　by　nZVI-C,　respectively.　nZVI-C　hastened　Nitrosomonas　enrichment　(relative　abundance　raised　from　2.85%　to　12.28%)　by　increasing　tryptophan　content　in　EPS.　Furthermore,　nZVIC　proliferated　amo　gene　by　3.92　times　and　directly　generated　electrons,　stimulating　Ammonia　monooxygenase　(AMO)　co-metabolism　activity.　Concurrently,　via　antibiotic　resistance　genes　(ARGs)　horizontal　transfer,　Nitrosomonas　synergized　with　Arenimonas　and　Comamonadaceae　for　efficient　antibiotic　removal.　Moreover,　nZVI-C　mitigated　antibiotics　inhibition　of　electron　transfer　by　proliferating　genes　for　PN　and　anammox　electron　production　(hao,　hdh)　and　utilization　(amo,　hzs,　nir).　That　facilitated　electron　transfer　and　synergistic　substrate　conversion　between　ammonia　oxidizing　bacteria　(AOB)　and　anaerobic　ammonia　oxidizing　bacteria　(AnAOB).　Finally,　the　high　nitrogen　removal　efficiency　of　the　MABR-PN/A　system　was　achieved.