The　simultaneous　treatment　of　nitrate　(NO3-N　similar　to　50　mg　L-1)　and　domestic　wastewater　(ammonia　(NH4+-N)　similar　to　60.6　mg　L-1,　COD　similar　to　166.3　mg　L-1)　via　a　novel　partial　denitrification　(PD)-ANaerobic　AMMonium　OXidation　(ANAMMOX)　process　was　investigated　at　low　temperature　(12.9　similar　to　15.1　degrees　C).　Results　showed　that　desirable　performance　was　achieved　with　average　NO3-N,　NH4+-N　and　COD　removal　efficiencies　of　89.5%,　97.6%　and　78.7%,　respectively.　However,　deteriorated　sludge　settleability　in　PD　reactor　was　observed　during　operation,　which　bulked　with　serious　sludge　wash-out,　leading　to　excess　NO3-N　remaining　in　PD　effluent.　Fortunately,　a　satisfactory　nitrogen　removal　was　still　achieved　due　to　the　occurrence　of　partial　denitrification　in　ANAMMOX　reactor.　This　was　demonstrated　by　high-throughput　sequencing,　which　revealed　that　the　high　nitrite　(NO2-N)　production　denitrifying　bacteria　of　Thauera　was　detected　(6.1%).　ANAMMOX　(above　70%)　maintained　the　dominant　pathway　for　nitrogen　removal,　and　Candidatus　Jettenia　was　identified　as　the　major　ANAMMOX　species　accounted　for　2.7%.　(C)　2016　Elsevier　Ltd.　All　rights　reserved.