High　nitrate　(NO3--N)　concentration　in　the　effluent　of　wastewater　treatment　plants　(WWTPs),　cannot　meet　the　increasing　stringent　discharge　limits.　Hence,　the　tertiary　treatment　is　necessary　to　lower　the　total　nitrogen　concentration.　In　this　study,　an　innovative　partial　denitrification　(PD)-Anammox　process　was　applied　to　remove　the　nitrate　nitrogen　(20-40　mg　N/L)　from　secondary　effluent.　The　nitrate　wastewater　were　firstly　fed　to　PD　sequencing　batch　reactor　(SBR,　10　L)　to　produce　nitrite　along　with　the　low　carbon/nitrogen　ratio　(C/N)　municipal　sewage　(NH4+　of　57.8　mg　N/L,　COD　of　175.8　mg/L),　then　the　effluent　from　SBR　was　pumped　to　the　anaerobic　sludge　blanket　(UASB,　3.2　L)　performing　anammox　for　further　nitrogen　removal.　The　integrated　process　was　operated　for　224　days　with　the　secondary　effluent　to　municipal　sewage　volume　ratio　of　2.9-6.　The　results　suggested　that　an　excellent　nitrate　removal　efficiency　of　97.9%　was　achieved,　and　the　mean　removal　efficiency　of　NH4+-N　and　COD　from　municipal　sewage　were　95.2%　and　81.6%,　respectively,　leading　to　the　total　nitrogen　and　COD　concentration　in　the　final　effluent　as　low　as　4.0　mg　N/L　and　30.1　mg/L,　respectively.　Anammox　was　the　main　nitrogen　removal　pathway　with　a　mean　proportion　of　78.2%,　and　Candidatus_Brocadia　was　identified　as　the　dominating　genus.　Furthermore,　it　was　found　that　a　minor　nitrous　oxide　(N2O)　was　produced　in　the　integrated　process.　The　PD-Anammox　process　was　verified　to　be　economically　and　environmentally　feasible　for　retrofitting　of　existing　plants.