This work investigated how thermal and chemical pretreatments influenced the anaerobic ammonium oxidation process in anaerobic digestion using biogranules that had been acclimated to septage. The digestion experiments were performed in serum vials using thermally and chemically pretreated septage as the substrate. The experimental results indicated that beat pretreatment reduced both dinitrogen production and ammonium removal. HCl and NaOH pretreatments increased both values by near 45% and 55% over the control. Alkali addition was more efficient than acid addition in enhancing dinitrogen production and ammonium removal.