Article ? AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button. Tier 2 ? Original research — experimental, observational, or case-control study. Direct primary evidence. Sign in to save

Metabolic effects of Fe0 on simultaneously eliminating excessive acidification and upgrading biogas in mesophilic or thermophilic anaerobic reactor

Journal of Cleaner Production 2023 21 citations ? Citation count from OpenAlex, updated daily. May differ slightly from the publisher's own count. Score: 45 ? 0–100 AI score estimating relevance to the microplastics field. Papers below 30 are filtered from public browse.

Song Wang Song Wang Xin Kong, Song Wang Song Wang Xin Kong, Song Wang Song Wang Song Wang Xin Kong, Qingxia Li, Xin Kong, Xin Kong, Yifeng Zhang, Wenjing Zhang, Wenjing Zhang, Yifeng Zhang, Song Wang Jianan Niu, Yifeng Zhang, Jianan Niu, Song Wang Jin Yuan, Jin Yuan, Yifeng Zhang, Yifeng Zhang, Yifeng Zhang, Yifeng Zhang, Jin Yuan, Wenjing Zhang, Wenjing Zhang, Yifeng Zhang, Yifeng Zhang, Jianguo Liu, Yifeng Zhang, Yifeng Zhang, Yifeng Zhang, Wenjing Zhang, Jin Yuan, Yifeng Zhang, Song Wang Wenjing Zhang, Wenjing Zhang, Wenjing Zhang, Xiuping Yue, Song Wang Yili Liu, Yifeng Zhang, Song Wang

Summary

Researchers found that adding zero-valent iron (Fe0) powder to anaerobic digesters processing food waste prevented the acid buildup that often derails the process, while also boosting methane content above 80% — but the microbial communities and metabolic pathways responsible differed entirely between reactors run at normal versus elevated temperatures. The findings offer practical guidance for designing more stable waste-to-energy systems.

Excessive acidification and low methane (CH4) percentage are technical challenges restricting anaerobic digestion (AD) of kitchen waste, especially under high organic loading rate (OLR) conditions. Although the contribution of Fe0 powder to excessive acidification elimination and CH4 yield improvement in mesophilic AD (MAD) has been extensively reported, its impact on the thermophilic AD (TAD) process with more frequent excessive acidification problem is rarely studied. Moreover, the difference in microbial interactions and metabolic pathways between MAD and TAD reactors under Fe0 regulation was still unclear. In this study, we compared the performance of Fe0 dosing on excessive acidification elimination and biogas upgrading quality in both MAD and TAD reactors at different OLRs. The results showed that compared with excessive acidification or low CH4 percentage (less than 70%) in control reactors without Fe0 addition, the CH4 yield of MAD and TAD reactors with addition of Fe0 at OLR of 35 gVS/L were 470.88 mLCH4/gVS and 270.40 mLCH4/gVS, with higher CH4 composition of 81.32%–82.23% and 83.68%–88.48% respectively. Microbial diversity analysis showed a sharp distinction between MAD and TAD reactors with addition of Fe0. Analyses of co-occurrence networks and metabolic pathway presented hydrogenotrophic methanogenic pathway, in addition to acetoclastic methanogenesis, was dominant in MAD reactors as results of enhanced interspecies hydrogen transfer between Methanoculleus and some hydrogen producers, especially under high OLR condition. In contrast, syntrophilic acetate oxidization - hydrogenotrophic methanogenesis, which dominated by Methanothermobacter and Alkaliphilus or Pelotomaculum, was the sole methanogenic pathway in TAD reactors. The results will shed lights on the regulation mechanisms of Fe0 in AD of kitchen waste under mesophilic and thermophilic conditions, offering new insight into development of more efficient waste to energy conversion technologies.

Read via DOI Download PDF

Share this paper

Post Share Share Pin Email