Reveling the micromolecular biological mechanism of acetate, thiosulfate and Fe 0 in ecological floating beds for treating low C/N wastewater: Insight into nitrogen removals and greenhouse gases reductions.

Autor: Sun S; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China., Yan P; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China., Zhang M; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China., Fan Y; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China., Gu X; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China., Chachar A; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China., He S; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China; Shanghai Engineering Research Center of Landscape Water Environment, Shanghai 200031, PR China. Electronic address: shengbing_he@163.com.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Oct 01; Vol. 945, pp. 174042. Date of Electronic Publication: 2024 Jun 20.
DOI: 10.1016/j.scitotenv.2024.174042
Abstrakt: Selecting an appropriate electron donor to enhance nitrogen removal for treating low C/N wastewater in ecological floating beds (EFBs) is controversy. In this study, a systematic and comprehensive evaluation of sodium acetate (EFB-C), sodium thiosulfate (EFB-S) and iron scraps (EFB-Fe) was performed in a 2-year experiment on long-term viability including nitrogen removal and greenhouse gas emissions associated with key molecular biological mechanisms. The results showed that EFB-C (43-85 %) and EFB-S (40-88 %) exhibited superior total nitrogen (TN) removal. Temperature and hydraulic retention time (HRT) have significant impacts on TN removal of EFB-Fe, however, it could reach 86 % under high temperature (30-35 °C) and a long HRT (3 days), and it has lowest N 2 O (0-6.2 mg m -2 d -1 ) and CH 4 (0-5.3 mg m -2 d -1 ) fluxes. Microbial network analysis revealed that the microbes changed from competing to cooperating after adding electron donors. A higher abundance of anammox genera was enriched in EFB-Fe. The Mantel's test and structural equation model provided proof of the differences, which showed that acetate and thiosulfate were similar, whereas Fe 0 was different in the nitrogen removal mechanism. Molecular biology analyses further verified that heterotrophic, autotrophic, and mixotrophic coupled with anammox were the main TN removal pathways for EFB-C, EFB-S, and EFB-Fe, respectively. These findings provide a better understanding of the biological mechanisms for selecting appropriate electron donors for treating low C/N wastewater.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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