Nitrous emission from a SBR wastewater treatment system under different NH4 + concentration

Nitrous emission in SBR denitrification process and the microbial community impact on it were studied. Result showed that the relationship between the N2O emission and conversion efficiency of nitrogen in system during the wastewater nitrogen removal process is negatively correlated. Under the experimental conditions, with NH4 + concentration increased, the efficiency of nitrogen transformation is decreased in this SBR system, meantime the N2O-N ratio is rapidly increase. Using PCR-DGGE technique analysis characteristics of microbial communities in SBR system under the different concentrations of NH4 + Showed that in high NH4 + concentration(60 mg · L-1) the microbial community is quite different when compared to medium (40 mg · L-1) and low(20 mg · L-1) concentrations. N 2O emission in high NH4 + concentration was effected by the nitrogen conversion efficiency and the changes in microbial community. In this study, the proportion of N2O-N is 0.25%∼6.35% in the wastewater nitrogen removal process under different NH4 + concentrations. © 2011 IEEE.