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ORIGINAL RESEARCH article

Front. Bioeng. Biotechnol.
Sec. Bioprocess Engineering
Volume 12 - 2024 | doi: 10.3389/fbioe.2024.1397294
This article is part of the Research Topic Bioprocess and Bioengineering for Waste Treatment and Recycling View all 6 articles

Insight into a single chamber air-cathode microbial fuel cell for nitrate removal and ecological roles

Provisionally accepted
Xiaojun Jin Xiaojun Jin 1Nuan Yang Nuan Yang 2Dake Xu Dake Xu 1Cheng Song Cheng Song 3Hong Liu Hong Liu 3*
  • 1 Northeastern University, Shenyang, Liaoning Province, China
  • 2 Ministry of Agriculture and Rural Affairs, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, Sichuan Province, China
  • 3 Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences (CAS), Chongqing, Chongqing Municipality, China

The final, formatted version of the article will be published soon.

    Bioelectrochemical systems is a sustainable and potential technology in wastewater treatment for nitrogen removal. The present study fabricated an air-cathode denitrifying microbial fuel cell (DNMFC) with modular revisable and investigated the metabolic processes using nutrients together with the spatiotemporal distribution characteristics of the dominated microorganisms. Based on the detection of organics and solvable nitrogen concentrations as well as electron generations in DNMFCs under different conditions, the distribution pattern of nutrients could be quantified. By calculation it is found that heterotrophic denitrification performed in DNMFC using 56.6% COD decreased the coulombic efficiency from 38.0% to 16.5% at a COD/NO3 --N ratio of 7. Furthermore, biological denitrification removed 92.3% nitrate, while the residual was reduced via electrochemical denitrification in the cathode. Correspondingly, nitrate as the electron acceptor consumed 16.7% of the all generated electrons and the residual electrons were accepted by oxygen. Microbial community analysis revealed that the bifunctional bacteria of electroactive denitrifying bacteria distributed all over the reactor determined the DNMFC performance; meanwhile, electroactive bacteria was mainly distributed in the anode biofilm, anaerobic denitrifying bacteria was adhered to the wall, and facultative anaerobic denitrifying bacteria was distributed in the wall and cathode. Characterizing the contribution of specific microorganisms in DNMFC comprehensively revealed the significant role of electroactive denitrifying bacteria and their cooperative relationship with other functional bacteria.

    Keywords: microbial fuel cells, Nitrate removal, Nutrient distribution, Denitrifying bacteria, electroactive denitrifying bacteria

    Received: 07 Mar 2024; Accepted: 27 May 2024.

    Copyright: © 2024 Jin, Yang, Xu, Song and Liu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Hong Liu, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences (CAS), Chongqing, 400714, Chongqing Municipality, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.