Mature　landfill　leachate　is　difficult　to　be　treated　due　to　its　complex　composition,　high　concentration　of　ammonia,　and　low　carbon/nitrogen　ratio　(C/N).　Simultaneous　partial　nitrification,　Anammox　and　denitrification　(SNAD)　with　intermittent　aeration　was　developed　to　achieve　nitrogen　removal　from　mature　landfill　leachate.　An　ammonia　conversion　efficiency　of　99.3　+/-　0.3%　and　total　nitrogen　(TN)　removal　efficiency　of　99　+/-　0.1%　were　obtained　under　the　influent　NH4+　-N,　SCOD　and　TN　of　1950　+/-　250　mg/L　1900　+/-　200　mg/L　and　2300　+/-　75　mg/L,　respectively.　Full　utilization　of　carbon　source　and　high　efficient　Anammox　were　two　significant　factors　in　SNAD　process.　Based　on　the　nitrogen　balance,　the　nitrogen　removal　contribution　was　77.1%　for　Anammox,　and　15.6%　for　dehitrification.　Three　dimensional　excitation-emission　matrix　(EEM)　fluorescence　spectroscopy　was　used　to　detect　dissolved　organic　matter　(DOM)　in　a　typical　operation　cycle　for　the　first　time,　demonstrating　that　DOM　increased　during　the　anoxic　phase　and　facilitated　the　reduction　of　excess　NO3--N　by　denitrification.　Quantitative　polymerase　chain　reaction　(QPCR)　analysis　revealed　dominant　bacterial　groups,　aerobic　ammonia-oxidizing　bacteria　(AOB)　and　anaerobic　ammonia　oxidizing　bacteria　(AnAOB),　which　accounted　for　12.99%　and　8.32%　of　total　bacteria　respectively.　As　a　whole,　in　the　SNAD　process,　nitrogen　and　COD　are　removed　from　the　wastewater　simultaneously.　(C)　2016　Elsevier　B.V.　All　rights　reserved.