Anaerobic　ammonium　oxidation　(anammox)　has　been　widely　accepted　as　an　energy-efficient　approach　for　nitrogen　removal　from　high-strength　sidestreams.　However,　insufficient　nitrogen　removal　due　to　the　excessive　NO3--N　residue　represents　the　major　challenge,　especially　at　low　temperature.　In　this　study,　highly　efficient　and　synchronous　nitrogen　removal　from　ammonia-rich　wastewater　and　real　domestic　wastewater　was　achieved　via　a　novel　anammox-mediated　treatment　by　coupling　with　double-nitrite-shunt　process　in　two-stage　sequencing　batch　reactors.　Stable　partial　nitrification/anammox　(PNA)　was　successfully　developed,　while　the　total　nitrogen　(TN)　removal　efficiency　was　limited　to　86.9　%　due　to　excessive　NO3--N　accumulation.　Significantly,　integration　with　partial　denitrification　(NO3--N.　NO2--N)　coupling　anammox　(PDA)　process　offered　an　efficient　solution,　which　transformed　the　overproduced　NO3--N　of　PNA　to　NO2--N　and　subsequently　completely　removed　with　NH4+-N　via　anammox　pathway　by　mixing　with　real　domestic　wastewater　(NH4+-N　of　69.0　mg/L,　COD　of　203.6　mg/L).　Excellent　nitrogen　removal　performance　with　average　TN　removal　efficiency　of　98.4　%　and　high-quality　effluent　with　average　TN　of　4.9　mg/L　was　maintained　despite　the　temperature　dropping　to　13.0　degrees　C.　S-16　rRNA　gene　sequencing　unveiled　the　different　community　of　anammox　bacteria　cooperating　stably　with　AOB　and　denitrifiers　in　the　two　systems.　Compared　with　conventional　nitrification/denitrification　methods,　the　novel　PNA-PDA　process　not　only　enabled　60%　saving　in　aeration　energy　and　95.5%　saving　in　organic　carbon　for　ammonia-rich　wastewater　treatment,　but　also　required　no　aeration　energy　for　domestic　wastewater　treatment.　Overall,　this　study　provides　a　promising　application　with　simple-control　strategy　for　cost-effective　and　synchronous　nitrogen　removal　from　sidestreams　and　mainstreams.