KOH activation increased biochar's capacity to regulate electron transfer and promote methanogenesis

Qing-Hua Liu, Yu-Hong Qiu and Zhi-Man Yang

Energy, 2025, vol. 322, issue C

Abstract: Accelerating direct interspecies electron transfer (DIET) between syntrophic partners can boost methanogenesis. Although biochar can promote DIET, low specific surface area (SSA) and electron transfer capacity (ETC) limit its application. KOH activation can improve SSA and ETC of biochar and its effectiveness in methanogenesis, yet the related methanogenic mechanism remains unclear, particularly for association between the KOH-activated biochar's properties and microbes. Herein, three biochars produced at 300, 500 and 800 °C were used to generate the corresponding KOH-activated biochars via a sequential carbonization and KOH activation procedure (CKAP) at 800 °C, which were labeled as CKAP300, CKAP500 and CKAP800, respectively. The effectiveness of KOH activation relied on the biochar type, exhibiting an increase of 92–1532 times in SSA and 11–22 % in graphitization degree. The KOH-activated biochar outperformed the pristine biochar in promoting methanogenesis, with a maximum increase of 75 % in methane yield and 3.1 times in maximum methane production rate (Rm). CKAP800 enhanced methane yield by 12 % and Rm by 29 % compared to CKAP300 and CKAP500, possibly due to the facts that high SSA facilitated the attachment and interaction of DIET partners (Treponema and Methanosaeta), and that high graphitization degree, c-type cytochrome and C-O groups promoted the DIET-based syntrophic metabolism.

Keywords: Anaerobic digestion; Electron transfer; Biochar; KOH activation (search for similar items in EconPapers)
Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0360544225012927
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:energy:v:322:y:2025:i:c:s0360544225012927

DOI: 10.1016/j.energy.2025.135650

Access Statistics for this article

Energy is currently edited by Henrik Lund and Mark J. Kaiser

More articles in Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().