Sulfur bacteria-reinforced microbial electrochemical denitrification

Sen Lin; Wentao Tang; Yihang Xiao; Feixiang Zan; Xiaoming Liu; Guanghao Chen; Tianwei Hao

doi:10.1016/j.biortech.2023.130121

Sulfur bacteria-reinforced microbial electrochemical denitrification

Bioresour Technol. 2024 Feb:393:130121. doi: 10.1016/j.biortech.2023.130121. Epub 2023 Nov 27.

Authors

Sen Lin¹, Wentao Tang¹, Yihang Xiao², Feixiang Zan³, Xiaoming Liu⁴, Guanghao Chen⁵, Tianwei Hao⁶

Affiliations

¹ Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China; Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau.
² Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau.
³ School of Environmental Science and Engineering, Low-Carbon Water Environment Technology Center (HUST-SUKE), Key Laboratory of Water and Wastewater Treatment, MOHURD, Huazhong University of Science and Technology, Wuhan, China.
⁴ School of Materials and Environment Engineering, Shenzhen Polytechnic, Shenzhen, China.
⁵ Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
⁶ Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau. Electronic address: twhao@um.edu.mo.

PMID: 38029802
DOI: 10.1016/j.biortech.2023.130121

Abstract

Two limiting factors of microbial electrochemical denitrification (MED) are the abundance and efficiency of the functional microorganisms. To supply these microorganisms, MED systems are inoculated with denitrifying sludge, but such method has much room for improvement. This study compared MED inoculated with autotrophic denitrifying inoculum (ADI) versus with heterotrophic denitrifying inoculum (HDI). ADI exhibited electroactivity for 50% less of timethan HDI. The denitrification efficiency of the ADI biocathode was42% higherthan that of the HDI biocathode. The HDI biocathode had high levels of polysaccharides while the ADI biocathode was rich in proteins, suggesting that two biocathodes may achieveMED but via differentpathways. Microbial communities of two biocathodes indicated MED of HDI biocathode may rely on interspecies electron transfer, whereas sulfur bacteria of ADI biocathode take electrons directly from the cathode to achieve MED. Utilizing autotrophic sulfur-oxidizing denitrifiers, this study offers a strategy for enhancing MED.

Keywords: Bio-electrochemical wastewater treatment; Biological nitrogen removal; Microbial electrochemical denitrification; Sulfur bacteria.

MeSH terms

Autotrophic Processes
Bacteria / metabolism
Bioreactors / microbiology
Denitrification*
Nitrates* / metabolism
Nitrogen / metabolism
Sulfur / metabolism

Substances

Nitrates
Sulfur
Nitrogen