Enhanced methane production and biofouling mitigation by Fe2O3 nanoparticle-biochar composites in anaerobic membrane bioreactors
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Supporting information
Accepted version
Author(s)
Zhang, Qianqian
Yang, Yu
LEE, Chung-Hak
Graham, Nigel JD
Ng, How Yong
Type
Journal Article
Abstract
Conductive materials present an innovative approach to enhancing methane production while facilitating sludge reduction and recovering resources in anaerobic digestion systems. However, the synergistic mechanisms by which composite materials influence the performance of anaerobic membrane bioreactor (AnMBR)—particularly in improving methane production and mitigating membrane fouling, remain underexplored. To address this, Fe2O3 nanoparticle-biochar composites (Fe2O3-BC) were synthesized to enhance electrical conductivity and promote efficient electron transfer in AnMBRs system. These results demonstrated that Fe2O3-BC exhibit high electron donor and electron acceptor capacities, increasing electron transport system (ETS) activity and conductivity by 1.4-fold and 1.7-fold, respectively. This enhancement accelerated the degradation of organic matter during the hydrolysis-acidification stage and boosted the activity of key enzymes (CytC and F420) in the methanogenic phase, resulting in a 42 % increase in methane production. Microbial community analysis indicated that Fe2O3-BC strengthened the methanogenic pathway by fostering efficient metabolic interactions between acidogenic bacteria (e.g., norank_f_Rikenellaceae) and methanogens (e.g., Methanosaeta). Long-term experiments with the Fe3BC25-AnMBR reactor showed a significant reduction in the accumulation of soluble microbial products (SMP) and extracellular polymeric substances (EPS) on membrane surfaces, along with a decline in fouling-related bacteria (e.g., Bacteroidota), mitigating membrane fouling by approximately 20–65 %. Furthermore, Fe3BC25 inhibited biofilm-related quorum sensing (QS) signals (e.g., C6-HSL, AI-1, and AI-2), reducing microbial adhesion and biofouling. Simultaneously, it enhanced methanogenesis by upregulating QS signals associated with methane production (e.g., C10-HSL). Fe2O3-BC is expected to offer a promising strategy for advancing energy-driven AnMBR processes.
Date Issued
2025-07-15
Date Acceptance
2025-03-19
Citation
Water Research, 2025, 280
ISSN
0043-1354
Publisher
Elsevier
Journal / Book Title
Water Research
Volume
280
Copyright Statement
© 2025 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
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Publication Status
Published
Article Number
123522
Date Publish Online
2025-03-20