This study investigates the role of Zero-Valent Iron (ZVI) in anaerobic digestion, emphasizing the critical influence of bicarbonate and feeding regimes. Abiotic tests revealed that higher bicarbonate concentrations enhanced hydrogen production. However, two-cycle experiments with ZVI and bicarbonate showed reduced hydrogen in the second cycle due to ZVI passivation. A similar phenomenon was observed when anaerobic granular sludge (AGS) was introduced into the system. Glucose at 4, 8, and 16 g/L was tested with AGS, with ZVI-containing samples achieving superior methane production, exceeding 95 % methane and CO levels below 0.5 % after 85 days in the 16 g/L reactor. In-situ ZVI addition using cheese whey reached ∼ 90 % methane without lag phases, outperforming ex-situ systems. Tests with Stainless Steel (SS316) showed no significant impact on methane or microbial profiles. This study highlights the novel role of bicarbonate in enhancing ZVI's effectiveness, providing new insights to optimize biogas upgrading in anaerobic digestion systems.
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http://dx.doi.org/10.1016/j.biortech.2025.132236 | DOI Listing |
Nat Food
March 2025
Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, USA.
Global food loss and waste continues to increase despite efforts to reduce it. Food waste causes a disproportionally large carbon footprint and resource burdens, which require urgent action to transition away from a disposal-dominated linear system to a circular bioeconomy of recovery and reuse of valuable resources. Here, using data from field-based studies conducted under diverse conditions worldwide, we found collective evidence that composting, anaerobic digestion and repurposing food waste to animal feed (re-feed) result in emission reductions of about 1 tCOe t food waste recycled compared with landfill disposal.
View Article and Find Full Text PDFBioresour Technol
March 2025
School of Chemistry and Life Resources, Renmin University of China, Beijing 100872, PR China. Electronic address:
The effective enhancement of short-chain fatty acid co-metabolic methane production is a research hotspot. N-acyl homoserine lactones (AHLs) are effective means regulating anaerobic digestion behaviors. However, what factors influence the secretion of endogenous signaling molecules has not been studied.
View Article and Find Full Text PDFSci Total Environ
March 2025
Norwegian Institute for Water Research, Oslo, Norway. Electronic address:
The increasing use of engineered nanoparticles (NPs) and their release into the environment requires an assessment of their fate and (eco-) toxicological effects. Previous studies have often focused on pristine NPs or NPs spiked into the effluent of simulated wastewater treatment plants (WWTP) fed with artificial wastewater, combined with unrealistic high exposure concentrations to overcome problems associated with high metal background concentrations. In this study environmentally transformed NPs were obtained by direct spiking into an anaerobic digester filled with municipal sewage sludge.
View Article and Find Full Text PDFHeliyon
February 2025
Department of Food and Nutritional Sciences, University of Reading, RG6 6AP, Reading, UK.
Anaerobic digestion (AD) plants have been facing significant challenges in maintaining a stable long-time operation when utilizing whey permeate as feedstock. In this study, we investigated the AD performance of whey permeate under batch and semi-continuous stirred tank reactor (s-CSTR) systems to optimize the process. Biochemical methane potential (BMP) tests were initially performed in batch reactors to assess whey permeate potential as AD substrate operating at different inoculum to substrate ratios (ISRs) and pH values under mesophilic temperatures.
View Article and Find Full Text PDFBiotechnol Biofuels Bioprod
March 2025
Environmental Biotechnologies, Institute of Microbiology (IM) DACD Campus Mendrisio, University of Applied Sciences and Arts of Southern Switzerland SUPSI, Via Flora Ruchat-Roncati, 6850, Mendrisio, Switzerland.
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