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

• Published in: iScience 2024-10, Vol.27 (10), p.110965, Article 110965
• Main Authors: Li, Ruitao, Ren, Xiang-peng, Fan, Xinxin, Zhang, Zhen, Gao, Tian-peng, Liu, Ying
• Format: Article
• Language: English
• Subjects: applied sciences; Biomaterials
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2024.110965

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. [Display omitted] •An efficient bio-cathode MFC method was reported to enrich denitrifying culture MBD•MBD showed a NO3−-N removal efficiency of 69.99 ± 0.60% without added organic carbon•Paracoccus and Pseudomonas was the dominant genera in the MBD for NO3−-N removal•An isolated strain Lyy (S. stutzeri) showed higher than 93% NO₃--N removal value Biomaterials, Applied Sciences