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

Zhijie Zeng; Yiying Wang; Wenxuan Zhu; Tian Xie; Lingling Li

doi:10.1016/j.heliyon.2023.e14920

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

Heliyon. 2023 Mar 29;9(4):e14920. doi: 10.1016/j.heliyon.2023.e14920. eCollection 2023 Apr.

Authors

Zhijie Zeng¹, Yiying Wang², Wenxuan Zhu¹, Tian Xie³, Lingling Li¹

Affiliations

¹ College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao, 266042, PR China.
² Qilu Petrochemical Engineering Company, Zibo, 255400, China.
³ Qingdao Urban Architectural Design Institute Co. LTD, Qingdao, 266042, China.

Abstract

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.

Keywords: COD/NO3−-N ratio; Electron acceptor; Microbial community; NO2−-N accumulation.