Biochar promoted microbial iron reduction in competition with methanogenesis in anaerobic digestion

Yafei Cheng; Zhijian Shi; Yan Shi; Yalei Zhang; Shicheng Zhang; Gang Luo

doi:10.1016/j.biortech.2023.129561

Biochar promoted microbial iron reduction in competition with methanogenesis in anaerobic digestion

Bioresour Technol. 2023 Nov:387:129561. doi: 10.1016/j.biortech.2023.129561. Epub 2023 Jul 26.

Authors

Yafei Cheng¹, Zhijian Shi¹, Yan Shi¹, Yalei Zhang², Shicheng Zhang³, Gang Luo⁴

Affiliations

¹ Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
² Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China; State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China.
³ Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; Shanghai Technical Service Platform for Pollution Control and Resource Utilization of Organic Wastes, Shanghai 200438, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China.
⁴ Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China; Shanghai Technical Service Platform for Pollution Control and Resource Utilization of Organic Wastes, Shanghai 200438, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China. Electronic address: gangl@fudan.edu.cn.

PMID: 37506931
DOI: 10.1016/j.biortech.2023.129561

Abstract

Microbial Fe (III) reduction generally could outcompete methanogenesis due to its thermodynamic advantage, while the low bioavailability of Fe (III) compounds limits this process in the anaerobic digestion system, which could result in the low recovery of vivianite. Therefore, this study investigated the competition between Fe (III) reduction and methanogenesis in the presence of different biochar (pyrochar and hydrochar). The results showed that pyrochar obtained at 500 °C (P5) resulted in the highest Fe (III) reduction (80.3%) compared to the control experiment (29.1%). P5 also decreased methane production by 9.4%. Both conductivity and surface oxygen-containing functional groups contributed to the promotion of direct electron transfer for Fe (III) reduction. Genomic-centric metatranscriptomics analysis showed that P5 led to the highest enrichment of Geobacter soli A19 and induced the significant expression of out membrane cytochrome c and pilA in Geobacter soli A19, which was related to higher Fe (III) reduction.

Keywords: Genomic-centric metatranscriptomics analysis; Hydrochar; Methanogenesis; Microbial Fe (III) reduction; Pyrochar.

MeSH terms

Anaerobiosis
Electron Transport
Iron* / metabolism
Methane*

Substances

biochar
Iron
Methane

Supplementary concepts

Geobacter soli