Anammox　process　is　a　cost-effective　solution　for　nitrogen　removal,　whereas　unsatisfactory　effluent　with　nitrate　accumulation　is　usually　achieved　in　treating　domestic　sewage,　owning　to　the　unwanted　prevalence　of　nitrite-oxidizing　bacteria　(NOB)　and　the　intrinsic　nitrate　production　by　anammox　bacteria.　Herein,　a　pilot-scale　system　integrating　Partial　Nitritation　and　simultaneous　Anammox,　Denitrification　and　Sludge　Fermentation　(PN　+　ADSF)　process　was　developed　to　treat　real　municipal　wastewater.　In　this　process,　PN　was　accomplished　in　a　sequencing　batch　reactor　(SBR)　using　the　strategy　of　intermittent　hydroxylamine　addition,　while　ADSF　coupling　anammox　and　heterotrophic　denitrification　was　conducted　in　an　up-flow　anaerobic　sludge　blanket　reactor　(UASB)　to　further　remove　nitrogen.　The　pilotscale　system　achieved　total　inorganic　nitrogen　(TIN)　concentrations　of　10.0　mg　N/L　in　effluent　and　sludge　reduction　efficiency　of　42.3%　simultaneously.　The　characterization　on　microbial　communities　revealed　that　Candidatus　Kuenenia　and　Thauera　were　the　dominant　functional　bacteria　for　anammox　and　denitrification,　respectively.　Supported　by　the　slow-release　carbon　sources　from　sludge　fermentation,　heterotrophic　denitrification　contributed　to　about　28%　of　nitrogen　removed　from　the　UASB,　while　anammox　played　a　more　important　role　in　nitrogen　removal.　The　pilot-scale　demonstration　confirmed　that　the　PN　+　ADSF　process　is　technically　feasible　for　enhanced　nitrogen　removal　and　sludge　reduction.