Effect of COD/ NO3−-N ratio on nitrite accumulation and microbial behavior in glucose-driven partial denitrification system

• Published in: Heliyon Vol. 9; no. 4; p. e14920
• Main Authors: Zeng, Zhijie, Wang, Yiying, Zhu, Wenxuan, Xie, Tian, Li, Lingling
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2023; Elsevier
• Subjects: carbon; COD/NO3−-N ratio; community structure; denitrification; Electron acceptor; genus; glucose; microbial communities; Microbial community; nitrites; NO2−-N accumulation; Thauera; NO2−-N accumulation; COD/NO3−-N ratio; Microbial community; Electron acceptor
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2023.e14920

COD/NO3−-N ratio was considered to be one of the key factors achieving effective nitrite accumulation during partial denitrification. In two parallel reactors incubated with glucose as carbon source at COD/NO3−-N of 3 and 5, respectively, the microbial community structure shift and the nitrite accumulation performance during long-term operation were investigated. The maximum nitrite accumulation ratios at COD/NO3−-N of 3 and 5 were 17.9% and 47.04%, respectively. Thauera was the dominant genus in both reactors on day 220 with the relative abundance of 18.67% and 64.01%, respectively. Batch experiments with different electron acceptors suggested that the distinction in nitrite accumulation at COD/NO3−-N of 3 and 5 might be caused by the differences in the abundance of Thauera. [Display omitted] •The bacterial structure in PD was significantly related to the C/N ratio.•NAR was much higher at C/N of 5 than that at C/N of 3.•The distinction in NAR at C/N of 3 and 5 might be related with Thauera abundance.