| Through controlling the concentration of free ammonia in the sequencing batch reactor(SBR), the single-stage autotrophic biological nitrogen removal process was achieved, including partial nitrification and anaerobic ammonium oxidation . The experiment was completed via two steps, the enrichment of nitrite bacteria and the inoculation of the mixture of anammox biomass. The operating temperature in the SBR was（31±2）℃. During the step of the enrichment of nitrite bacteria, pH was about 7.8. Changes of FA concentration were achieved by controlling the concentration of influent NH+4-N（56-446 mg·L-1）, in order to inhibit and eliminate the nitrate bacteria. The activity tests of the sludge, 55d after enrichment, showed strong activity of aerobic ammonium oxidation ［2.91 kg·(kg·d) -1］ and low activity of nitrite oxidation ［0.03 kg·(kg·d) -1］. During the inoculation of the mixture of anammox biomass, changes of FA concentration were achieved by controlling the concentration of influent NH+4-N and pH. As the inoculation of anammox biomass , abundant of bacteria and nutrient content were into the reactor and there kept high activity of aerobic ammonium oxidation ［2.83 kg·(kg·d) -1］ and a certain activity of nitrite oxidation , at the same time , the activity of anammox and heterotrophic denitrification reached 0.65 kg·(kg·d) -1and 0.11 kg·(kg·d) -1, respectively. |
