Mechanisms and microbial structure of partial denitrification with high nitrite accumulation
Mechanisms and microbial structure of partial denitrification with high nitrite accumulation
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DOI：
10.1007/s00253-015-7052-9
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发表时间：
2016-02-01
影响因子：
5
通讯作者：
Niu, Meng
中科院分区：
文献类型：
--
作者：
Du, Rui;Peng, Yongzhen;Niu, Meng
反硝化过程中亚硝酸盐（NO2（-）-N）的积累为厌氧氨氧化提供了底物，厌氧氨氧化是一种高效、经济的污水脱氮工艺。本研究旨在以乙酸盐为唯一有机碳源，通过长期运行获得较高的NO2（-）-N积累量，并阐明NO2（-）-N积累的机理。结果表明，土壤硝态氮（NO3（-）-N）的比还原速率在NO3（-）-N浓度为20 mg/L时，VSS为59.61 mg N·h（-1），远高于比NO2（-）-N还原速率NO_3 ~（-）-N浓度为20 mg/L时，NO_2 ~（-）-N的积累速率为7.30 mg N·VSS ~（-1）·h ~（-1），NO_3 ~（-）-N转化为NO_2 ~（-）-N的转化率高达90%。NO2（-）-N的积累几乎不受化学需氧量（COD）与NO3（-）-N浓度比（C/N）的影响。随着NO3（-）-N的加入，NO2（-）-N发生了积累，比还原速率下降到比不加NO3（-）-N时低得多。这表明系统中的微生物更喜欢以NO3（-）-N作为电子受体而不是以NO2（-）-N作为电子受体。Illumina高通量测序分析表明，在NO2（-）-N积累量较高的湿地群落中，Thauera细菌占优势，占总微生物的67.25%。该菌可能具有在NO3（-）-N存在下高NO2（-）-N积累的功能。
Nitrite (NO2 (-)-N) accumulation in denitrification can provide the substrate for anammox, an efficient and cost-saving process for nitrogen removal from wastewater. This batch-mode study aimed at achieving high NO2 (-)-N accumulation over long-term operation with the acetate as sole organic carbon source and elucidating the mechanisms of NO2 (-)-N accumulation. The results showed that the specific nitrate (NO3 (-)-N) reduction rate (59.61 mg N VSS-1 h(-1) at NO3 (-)-N of 20 mg/L) was much higher than specific NO2 (-)-N reduction rate (7.30 mg N VSS-1 h(-1) at NO3 (-)-N of 20 mg/L), and the NO2 (-)-N accumulation proceeded well at the NO3 (-)-N to NO2 (-)-N transformation ratio (NTR) as high as 90 %. NO2 (-)-N accumulation was barely affected by the ratio of chemical oxygen demand (COD) to NO3 (-)-N concentration (C/N). With the addition of NO3 (-)-N, NO2 (-)-N accumulation occurred and the specific NO2 (-)-N reduction rate declined to a much lower level compared with the value in the absence of NO3 (-)-N. This indicated that the denitrifying bacteria in the system preferred to use NO3 (-)-N as electron acceptor rather than use NO2 (-)-N. In addition, the Illumina high-throughput sequencing analysis revealed that the genus of Thauera bacteria was dominant in the denitrifying community with high NO2 (-)-N accumulation and account for 67.25 % of total microorganism. This bacterium might be functional for high NO2 (-)-N accumulation in the presence of NO3 (-)-N.