Effects of Different Concentrations of Ammonia Nitrogen on N_2O Emission in the Process of Partial Nitrification

[Objective] The study aimed to discuss the effects of different concentrations of ammonia nitrogen on N2O emission in the process of partial nitrification.[Method] By using a sequencing batch biofilm reactor(SBBR) under intermittent aeration,the influences of various concentrations of influent ammonia nitrogen on nitrous oxide(N2O) emission from partial nitrification were analyzed.[Result] When the concentration of influent ammonia nitrogen varied from 200 to 400 mg/L,the changing trends of DO and ORP value were consistent during the process of partial nitrification,and the concentration ratio of NO-2-N to NH+4-N in the effluent reached 1∶1,with lower NO-3-N level.In addition,ammonia nitrogen concentration in the influent had a significant effect on N2O emission in the process of partial nitrification,that is,the higher the ammonia nitrogen concentration,the more the N2O emission.When ammonia nitrogen concentration was 400 mg/L,N2O emission was up to about 37 mg.[Conclusion] N2O emission in the process of partial nitrification might be related to the concentration of NH+4 and NO-2.