In　this　study,　a　novel　denitrification　reactor　is　used　to　treat　sludge　dewatering　liquor,　where　the　co-occurrence　of　sludge　fermentation　and　nitrate　reduction　was　obtained.　The　system　showed　an　efficient　and　stable　nitrogen　removal　performance.　When　the　effluent　recycle　ratio　was　200%,　TN　and　NH4+　removal　efficiency　was　99.6%　and　83.5%,　respectively.　In　addition,　primary　sludge　could　be　well　degraded　in　the　novel　system.　Over　50%　volatile　suspended　solid　(VSS)　of　primary　sludge　was　utilized,　and　the　ratio　of　VSS/SS　declined　from　0.76　to　0.39.　Further　investigation　with　batch　experiments　revealed　that,　compared　to　conventional　sludge　fermentation,　the　integration　of　denitrification　and　fermentation　was　better　at　carbon　production　as　well　as　the　control　of　ammonium　release.　(C)　2011　Elsevier　Ltd.　All　rights　reserved.