iScience (Oct 2024)

Efficient enriching high-performance denitrifiers using bio-cathode of microbial fuel cells

  • Ruitao Li,
  • Xiang-peng Ren,
  • Xinxin Fan,
  • Zhen Zhang,
  • Tian-peng Gao,
  • Ying Liu

Journal volume & issue
Vol. 27, no. 10
p. 110965

Abstract

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Summary: Recent advancements in microbial fuel cells (MFC) technology have significantly contributed to the development of bio-cathode denitrification as a promising method for eco-friendly wastewater treatment. This study utilized an efficient repeated replacement method to enrich a mixed bio-cathode denitrifying culture (MBD) within a bio-cathode MFC, achieving a stable maximum output voltage of 120 ± 5 mV and a NO3−-N removal efficiency of 69.99 ± 0.60%. The electrotrophic denitrification process appears to be facilitated by electron shuttles. Microbial community analysis revealed a predominance of Proteobacteria, with Paracoccus and Pseudomonas as functional genera. Additionally, the isolated strain Lyy (belonging to Stutzerimonas) from MBD demonstrated exceptional denitrification efficiencies exceeding 98% when treating wastewater with a broad range of C/N (2–12) ratios and KNO3 concentrations (500–3000 mg/L) within 60 h. These results demonstrated the effectiveness of the repeated replacement method in enriching bio-cathode denitrifiers and advancing MFC application in sustainable wastewater management.

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