Nitritation-anammox　process　was　successfully　established　in　pilot-　and　full-scale　integrated　fixed-film　activated　sludge　(IFAS)　reactors.　An　average　nitrogen　removal　efficiency　of　80%　was　achieved　under　ammonium　loading　rate　of　0.7-1.3　kg　N/(m(3)　d)　in　the　pilot-scale　reactor　(12　m(3)).　Moreover,　molecular　analysis　showed　that　ammonium　oxidizing　bacteria　(AOB)　were　more　abundant　in　the　activated　sludge　while　anammox　bacteria　were　primarily　located　in　the　biofilm.　The　segregation　of　AOB　and　anammox　bacteria　enhanced　the　nitrogen　removal　rate　and　operational　stability.　Furthermore,　a　full-scale　IFAS　reactor　of　500　m(3)　was　set-up　to　treat　sludge　dewatering　liquors.　An　average　nitrogen　removal　efficiency　of　85%　and　a　nitrogen　removal　rate　of　0.48　kg　N/(m(3)　d)　were　achieved　after　inoculation.　It　was　noted　that　high　influent　suspended　solids　would　seriously　affect　the　performance　of　the　IFAS　system.　Therefore,　a　pre-treatment　was　proposed　to　reduce　suspended　solid　in　the　full-scale　application.　(C)　2015　Elsevier　Ltd.　All　rights　reserved.