Study on the Nitrogen Removal Performance and the Characteristics of Denitrification Bacterial Community Structure of Biological Aerated Filter
曝气生物滤池工艺脱氮性能及反硝化细菌群落结构特征研究

The nitrogen removal performance and the denitrification bacterial community structure of two pre-denitrification biological aeration filter (BAF) processes with different media combinations, the ceramic-zeolite BAF process (C-Z BAF) and the zeolite-ceramic BAF process (Z-C BAF), were compared at different C/N ratios. The results showed that the average TN removal efficiency of Z-C BAF was higher than that of C-Z BAF, and the advantage was more notable at low C/N ratio. When the C/N ratio decreased to 3.3, the average TN removal efficiency of Z-C BAF was 20% higher than that of C-Z BAF. Comparing the microbial community structure of the two combinations at different C/N ratios, it was found that the richness and diversity of denitrification bacterial community decreased significantly with the decrease of C/N ratio. At low C/N ratio, within the whole oxic filter of Z-C BAF, nosZ genetic T-RFs were detected with more than 20% relative abundance, whereas no nosZ genetic T-RFs were detected at the upper oxic filter of C-Z BAF by PCR amplification. The results indicated that the simultaneous nitrification and denitrification function of Z-C BAF was better than that of C-Z BAF. At low C/N ratio, the nitrogen removal efficiency of Z-C BAF was obviously higher than that of C-Z BAF. Thus, compared to C-Z BAF, Z-C BAF had greater potential on the treatment of wastewater with low organic concentration and low C/N ratio.