Promotion of nitrogen removal in a denitrification process elevated by zero-valent iron under low carbon-to-nitrogen ratio

Ze-Tong Feng; Xin Ma; Ying-Jun Sun; Jia-Min Zhou; Zu-Gang Liao; Zhi-Cong He; Fei Ding; Qian-Qian Zhang

doi:10.1016/j.biortech.2023.129566

Promotion of nitrogen removal in a denitrification process elevated by zero-valent iron under low carbon-to-nitrogen ratio

Bioresour Technol. 2023 Oct:386:129566. doi: 10.1016/j.biortech.2023.129566. Epub 2023 Jul 26.

Authors

Ze-Tong Feng¹, Xin Ma¹, Ying-Jun Sun¹, Jia-Min Zhou¹, Zu-Gang Liao¹, Zhi-Cong He¹, Fei Ding¹, Qian-Qian Zhang²

Affiliations

¹ School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education, Chang'an University, Xi'an 710054, China.
² School of Water and Environment, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education, Chang'an University, Xi'an 710054, China. Electronic address: anammox@chd.edu.cn.

PMID: 37506936
DOI: 10.1016/j.biortech.2023.129566

Abstract

The nitrogen removal efficiency and distribution of microbial community in a denitrification process aided by zero-valent iron (ZVI) under low carbon-to-nitrogen ratio (C/N) were assessed in this study. Experimental results demonstrated that the nitrogen removal efficiency (TNRE) increased to 96.4 ± 2.72% and 63.3 ± 4.02% after continuous addition of ZVI with molar ratio of ZVI to nitrate (NO₃^--N) (ZVI/N) of 6 at C/N of 3 and 2, respectively, which was 4% and 7.7% higher than the blank one. Meanwhile, extracellular polymeric substance (EPS) could be used as electron transfer medium and endogenous carbon source for denitrification system and also the production of which increased by 28.43% and 53.10% under ZVI stimulation compared to the control group. Finally, a symbiotic system composed by autotrophic and heterotrophic denitrification bacteria was formed by aid of ZVI. This study proposed new insights into denitrification process improved by ZVI.

Keywords: Denitrification; Low C/N ratio; Mechanism; Performance; Zero-valent iron.

MeSH terms

Bioreactors
Carbon*
Denitrification
Extracellular Polymeric Substance Matrix
Iron*
Nitrates
Nitrogen

Substances

Iron
Carbon
Nitrogen
Nitrates