Autotrophic denitrification of NO for effectively recovering N2O through using thiosulfate as sole electron donor

Lan Wu; Li-Kun Wang; Wei Wei; Bing-Jie Ni

doi:10.1016/j.biortech.2022.126681

Autotrophic denitrification of NO for effectively recovering N₂O through using thiosulfate as sole electron donor

Bioresour Technol. 2022 Mar:347:126681. doi: 10.1016/j.biortech.2022.126681. Epub 2022 Jan 6.

Authors

Lan Wu¹, Li-Kun Wang², Wei Wei¹, Bing-Jie Ni³

Affiliations

¹ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia.
² State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
³ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia. Electronic address: bingjieni@gmail.com.

PMID: 34999195
DOI: 10.1016/j.biortech.2022.126681

Abstract

To reclaim nitrous oxide (N₂O) as an energy resource economically, this study developed an autotrophic denitrification-based system with thiosulfate (S₂O₃^2-) and nitric oxide (NO) as electron donor and acceptor, respectively. NO from flue gases is absorbed on Fe(II)EDTA to overcome its low solubility in liquid phase by forming Fe(II)EDTA-NO. Short-term batch tests and long-term continuous experiments were conducted to investigate the N₂O production profile and NO conversion efficiency from thiosulfate-based denitrification under varied Fe (II)EDTA-NO conditions (5-20 mM). Up to 39% of NO was converted to gaseous N₂O at 20 mM Fe(II)EDTA-NO amid batch test due to the inhibition of key enzymatic activities by NO and the acidic conditions following thiosulfate oxidation. Higher Fe(II)EDTA-NO levels induced lower enzymatic activities with N₂OR being suppressed harder than NOR. Microbial diversity was reduced in the continuous thiosulfate-driven Fe(II)EDTA-NO-based denitrification system. NO-resistant bacteria and sulfide-tolerant denitrifiers were enriched, facilitating NO conversion to N₂O thereafter.

Keywords: Autotrophic denitrification; Enzymatic activity; Microbial evolution; N(2)O; NO; Thiosulfate.

MeSH terms

Autotrophic Processes
Bioreactors
Denitrification*
Electrons
Nitric Oxide
Nitrous Oxide
Thiosulfates*

Substances

Thiosulfates
Nitric Oxide
Nitrous Oxide