Mechanisms and recent advances in proton-coupled electron transfer during anaerobic digestion of organic solid wastes

LI Xinyu; LIU Haoyu; DAI Xiaohu

doi:10.13205/j.hjgc.202610017

Volume 44 Issue 10

Oct. 2026

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LI Xinyu, LIU Haoyu, DAI Xiaohu. Mechanisms and recent advances in proton-coupled electron transfer during anaerobic digestion of organic solid wastes[J]. ENVIRONMENTAL ENGINEERING , 2026, 44(10): 170-180. doi: 10.13205/j.hjgc.202610017

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LI Xinyu, LIU Haoyu, DAI Xiaohu. Mechanisms and recent advances in proton-coupled electron transfer during anaerobic digestion of organic solid wastes[J]. ENVIRONMENTAL ENGINEERING , 2026, 44(10): 170-180. doi: 10.13205/j.hjgc.202610017

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Mechanisms and recent advances in proton-coupled electron transfer during anaerobic digestion of organic solid wastes

doi: 10.13205/j.hjgc.202610017

LI Xinyu^1,2,3,
LIU Haoyu^1
,,
DAI Xiaohu^1
,

1. School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China;
2. Shanghai HiQ Smart Data Co., Ltd., Shanghai 200441, China;
3. Shanghai E-Carbon Digital Technology Co., Ltd., Shanghai 200441, China

Received Date: 2026-08-27
Available Online: 2026-11-10

Abstract

Abstract

Anaerobic digestion is a key common technology for achieving the reduction of pollution and carbon emission cooperating with the improvement of resource utilization. The syntrophic methanogenesis process is highly dependent on energy metabolism centered on electron-proton transfer. Direct interspecies electron transfer （DIET） represents the mainstream regulatory paradigm for interspecies energy transfer. However， regulatory modes focusing on sole electron transfer would induce electron-proton uncoupling， triggering extracellular microenvironment acidification and limiting the enhancement efficiency of methanogenesis. Extracellular proton-coupled electron transfer （PCET） conducts synchronous electron-proton transfer， which reduces the reaction activation barrier while maintaining the acid-base homeostasis of the extracellular microenvironment， offering a novel perspective for boosting the energy transfer efficiency during anaerobic syntrophic metabolism of methanogenesis. However， existing relevant reviews predominantly focus on DIET， whereas the mechanisms， enhancement pathways and characterization methods of extracellular PCET in the anaerobic systems of organic solid waste have not yet been systematically reviewed. Herein， we systematically elucidate the fundamental principles of extracellular PCET mediated by cell membranes and extracellular polymeric substances （EPS） in anaerobic systems. The enhancement pathways of PCET driven by in-situ physicochemical regulation and exogenous functional materials， as well as their corresponding methanogenic promotion effects， are clarified. By integrating isotope kinetics， electrochemistry， and in-situ spectroscopy， a multi-scale characterization framework for PCET is synthesized. Furthermore， current challenges and future research directions are discussed. This review provides a scientific basis for the engineering regulation of high-efficiency anaerobic methanogenesis from organic solid waste.
- anaerobic digestion,
- syntrophic metabolism,
- energy transfer,
- proton-coupled electron transfer,
- methane production

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References(61)

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