Under　anaerobic　conditions,　ammonium　(NFU-)　can　react　with　nitrite　(NO2-)　and　sulfate　(SO42-),　termed　nitrite-anammox　(NirAnammox)　and　sulfate-anammox　(Sulfammox),　respectively.　However,　how　to　remove　NH4　and　SO4　together　from　leachate　is　unclear.　In　this　study,　NirAnammox　and　Sulfammox　cooperatively　achieved　nitrogen　and　sulfate　removal　from　leachate　using　a　biological　process　at　low　temperature　(14-15　degrees　C).　NH4+,　total　nitrogen　(TN),　and　SO42-　concentrations　in　the　influent　were　610　-700,　670-900,　1870-1920　mg/L,　respectively,　and　10　+/-　1,　35　+/-　3,　and　897.7　+/-　10　mg/L,　respectively,　in　the　effluent.　Sulfammox,　and　NirAnammox　(including　partial　nitrification)　removed　44.2%　and　35.46%　of　the　NH4+　respectively.　Therefore,　because　leachate　contains　high　concentrations　of　NH4+　and　SO42-,　NirAnammox　and　Sulfammox　can　easily　occur　together,　with　nitrogen　removal　by　Sulfammox　being　more　than　NirAnammox.　The　relative　abundance　of　dominant　bacteria　of　the　Sulfammox　were　10-20　times　that　of　Candidatus　Kuenenia　(NirAnammox)　in　each　reactor.　Organic　matter　negatively　affected　NirAnammox,　but　not　Sulfammox.　Dissolved　oxygen　negatively　affected　both.　(C)　2019　Published　by　Elsevier　Ltd.