This　study　presents　a　novel　process　(i.e.　PN/SFDA)　to　remove　nitrogen　from　low　C/N　domestic　wastewater.　The　process　mainly　involves　two　reactors,　a　pre-Sequencing　Batch　Reactor　for　partial　nitritation　(termed　as　PN-SBR)　and　an　anoxic　reactor　for　integrated　Denitrification　and　Anammox　with　carbon　sources　produced　from　Sludge　Fermentation　(termed　as　SFDA).　During　long-term　Runs,　NO2/NH4+　ratio　(i.e.　NO2-N/NH4+-N　calculated　by　mole)　in　the　PN-SBR　effluent　was　gradually　increased　from　0.2　to　37　by　extending　aerobic　duration,　meaning　that　partial　nitritation　turning　to　full　nitritation　could　be　achieved.　Impact　of　partial　nitritation　degree　on　SFDA　process　was　investigated　and　the　result　showed　that,　NO2/NH4+　ratios　between　2　and　10　were　appropriate　for　the　co-existence　of　denitrification　and　anammox　together　in　the　SFDA　reactor,　and　denitrification　instead　of　anammox　contributed　greater　for　nitrogen　removal.　Further　batch　tests　indicated　that　anammox　collaborated　well　with　denitrification　at　low　C/N　(1.0　in　this　study).　(C)　2016　Elsevier　Ltd.　All　rights　reserved.