In　this　study,　a　model　was　developed　to　investigate　the　partial　denitrification(PD)　process.　The　heterotrophic　biomass　(XH)　proportion　in　the　sludge　was　determined　to　be　66.4%　based　on　metagenomic　sequencing.　The　kinetic　parameters　were　first　calibrated,　then　validated　using　the　batch　tests　results.　The　results　showed　rapid　decreases　in　the　chemical　oxygen　demand　(COD)　and　nitrate　concentrations　and　gradual　increases　in　the　nitrite　concentrations　in　the　first　four　hours,　then　remained　constant　from　4　to　8　h.　Anoxic　reduction　factor　(eta　NO3　and　eta　NO2)　and　half　saturation　constant　(KS1　and　KS2)　were　calibrated　at　0.097,　0.13,　89.28　mg　COD/L,　and　102.29　mg　COD/L,　respectively.　Whereas　the　simulation　results　demonstrated　that　the　increase　in　carbon-to-nitrogen　(C/N)　ratios　and　the　reduction　in　XH　contributed　to　the　increase　in　the　nitrite　transformation　rate.　This　model　provides　potential　strategies　for　optimizing　the　PD/A　process.