MINI REVIEW article

Front. Environ. Eng.

Sec. Water, Waste and Wastewater Engineering

Volume 4 - 2025 | doi: 10.3389/fenve.2025.1597684

Retrospective of DIET Process for Enhanced Biogas Production during Anaerobic Digestion of Thermal/Chemically Pretreated Waste Activated Sludge

Provisionally accepted
Abdulaziz Mohammed AlmegblAbdulaziz Mohammed Almegbl1Ali Mohammad RahmaniAli Mohammad Rahmani2,3Faris Mohammad A MunshiFaris Mohammad A Munshi1Kamaluddin KamalKamaluddin Kamal4Abbas KhursheedAbbas Khursheed5Muntjeer AliMuntjeer Ali2*Anwar KhursheedAnwar Khursheed1,6
  • 1Department of Civil Engineering, College of Engineering, King Saud University, Riyadh, Saudi Arabia
  • 2Indian Institute of Technology Roorkee, Roorkee, India
  • 33Water and Environmental Engineering Department, Faculty of Engineering, Kandahar University, Afghanistan, Kandahar, Afghanistan
  • 4Civil Engineering Department, Faculty of Engineering, Kandahar University, Afghanistan, Kandahar, Afghanistan
  • 5Department of Civil and Environmental Engineering, Faculty of Engineering and Design, Carleton University, Ottawa, Ontario, Canada
  • 6Department of Civil Engineering, Z.H. College of Engineering, AMU, Aligarh, India, Aligarh, India

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Hydrolysis of recalcitrant organic waste such as lignocellulosic biomass and waste-activated sludge (WAS) is a rate-limited step in anaerobic digestion (AD) due to the chemical and physical barriers that can be diminished by pretreatment of the waste. However, for readily biodegradable, soluble organics or already hydrolyzed organics, acetogenesis and methanogenesis become the rate-limiting steps owing to the discrepancy in the syntrophic relationship of the inter-microbial matrix. Enhancing the syntrophic relation of VFA oxidizing bacteria and hydrogenotrophic methanogens via direct interspecies electron transfer (DIET) is vital for enhanced and efficient bio-methanation. DIET changes the metabolic pathways, which can be evidenced by microbial diversity, abundance, and associated enzymes. The stimulation of DIET can enhance biogas production and methane content and enhance VFA and ammonia-stressed digesters. The conductive materials for DIET in AD should be non-hazardous, chemically stable, cheap, recyclable, non-reactive, porous, conductive, microbe-friendly, and provide a large surface area. DIET stimulation and optimization via sustainable materials for high organic wastes are the future research areas that need comprehensive exploration.

Keywords: anaerobic digestion, Syntrophic relation, direct interspecies electron transfer, Biogas production, Carbon-based materials

Received: 21 Mar 2025; Accepted: 28 May 2025.

Copyright: © 2025 Almegbl, Rahmani, Munshi, Kamal, Khursheed, Ali and Khursheed. 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: Muntjeer Ali, Indian Institute of Technology Roorkee, Roorkee, India

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.

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