This　study　presents　a　novel　denitratation/anammox　biofilter　(DABF)　for　nitrate　removal　from　secondary　effluent,　where　denitratation　(NO3--＞　NO2-)　is　coupled　with　anammox　(NO2-+NH4+-＞　N-2)　instead　of　denitritation　(NO2--＞　N-2).　Total　nitrogen　(TN)　was　removed　by　81.90%　in　this　DABF　when　the　average　effluent　TN　concentration　was　7.82　mg/L.　Meanwhile,　organic　carbon　source　consumption　and　backwash　sludge　production　in　the　DABF　were　reduced　by　63%　and　70%,　respectively,　compared　to　conventional　denitrifying　biofilter　(DNBF).　Nitrogen　banlance　analysis　indicates　that　93%　of　the　nitrogen　gas　produced　in　DABF　was　via　anammox.　Batch　tests　confirmed　that　the　DABF　biofilm　reduced　nitrite　using　ammonium　as　the　electron　donor,　and　accumulated　nitrite　during　denitratation,　thus　providing　nitrite　for　the　anammox　bacteria.　Moreover,　high-throughput　sequencing　approach　also　revealed　that　the　anammox　bacteria　Candidatus　Brocadia　dominated　the　community,　which　could　also　be　responsible　for　the　stable　processes　in　DABF　by　interacting　with　the　other　denitrifying　bacteria.