Efficient　recovery　of　nitrous　oxide　(N2O)　through　heterotrophic　denitrification　with　the　help　of　Fe(II)EDTA-NO　as　a　chelating　agent　has　been　regarded　as　an　ideal　technology　to　treat　nitric　oxide　(NO)-rich　flue　gas.　In　this　study,　an　integrated　NO-based　biological　denitrification　model　was　developed　to　describe　the　sequential　reduction　of　the　NO　fixed　in　Fe(II)EDTA-NO　with　organic　carbon　as　the　electron　donor.　With　the　inclusion　of　only　the　key　pathways　contributing　to　nitrogen　transformation,　the　model　was　firstly　developed　and　then　calibrated/validated　and　evaluated　using　the　data　of　batch　tests　mediated　by　the　identified　functional　heterotrophic　bacteria　at　various　substrates　concentrations　and　then　used　to　explore　the　possibility　of　enhancing　N2O　recovery　by　altering　the　substrates　condition　and　reactor　setup.　The　results　demonstrated　that　the　optimal　COD/N　ratio　decreased　consistently　from　1.5　g-COD/g-N　at　the　initial　NO　concentration　of　40　g-N/m3　to　1.0　g-COD/g-N　at　the　initial　NO　concentration　of　420　g-N/m3.　Furthermore,　sufficiently　increasing　the　headspace　volume　of　the　reactor　was　considered　an　ideal　strategy　to　obtain　ideal　N2O　production　of　86.6　%　under　the　studied　conditions.　The　production　of　high-purity　N2O　(98　%)　confirmed　the　practical　application　potential　of　this　integrated　treatment　technology　to　recover　a　valuable　energy　resource　from　NO-rich　flue　gas.　©　2022　Elsevier　B.V.