Anaerobic digestion of alkaline kraft elemental chlorine-free bleaching wastewater in two mesophilic, lab-scale upflow anaerobic sludge bed reactors resulted in significantly higher biogas production (250±50 vs. 120±30 NmL g [Formula: see text]) and reduction of filtered total organic carbon (fTOC) (60±5 vs. 43±6%) for wastewater from processing of hardwood (HW) compared with softwood (SW). In all cases, the gas production was likely underestimated due to poor gas separation in the reactors. Despite changes in wastewater characteristics, a stable anaerobic process was maintained with hydraulic retention times (HRTs) between 7 and 14 h. Lowering the HRT (from 13.5 to 8.5 h) did not significantly affect the process, and the stable performance at 8.5 h leaves room for further decreases in HRT. The results show that this type of wastewater is suitable for a full-scale implementation, but the difference in methane potential between SW and HW is important to consider both regarding process dimensioning and biogas yield optimization.
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http://dx.doi.org/10.1080/09593330.2014.994042 | DOI Listing |
J Dairy Sci
January 2025
Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, China 210095.
Anaerobic gut fungi (AGF) were the last phylum to be identified within the rumen microbiome and account for 7-9% of microbial biomass. They produce potent lignocellulases that degrade recalcitrant plant cell walls, and rhizoids that can penetrate the cuticle of plant cells, exposing internal components to other microbiota. Interspecies H transfer between AGF and rumen methanogenic archaea is an essential metabolic process in the rumen that occurs during the reduction of CO to CH by methanogens.
View Article and Find Full Text PDFBioresour Technol
January 2025
College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
Nanobubble water (NBW) or temperature-phased anaerobic digestion assisted by microbial electrolysis cell (MEC-TPAD) can promote sludge hydrolysis and methanogenesis. However, the role of the combined application of NBW and MEC-TPAD in terms of anaerobic performance and related microbial properties remains unclear. This study investigated the impact of Air-NBW on hydrolysis and methanogenesis of dewatered sludge MEC-TPAD.
View Article and Find Full Text PDFBioresour Technol
January 2025
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090 China. Electronic address:
Direct interspecies electron transfer (DIET) enhances anaerobic digestion by facilitating electron exchange between electroactive bacteria and methanogenic archaea. While Geobacter species are recognized for donating electrons to methanogens via DIET, they are rarely detected in mixed microbial communities. This study examined various non-electrode biological carriers (zeolite, carbon cloth, activated carbon and biochar) to promote Geobacter cultivation under anaerobic conditions and identify pivotal factors influencing their symbiosis with methanogens.
View Article and Find Full Text PDFWater Res
January 2025
MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China. Electronic address:
Anaerobic digestion (AD) viruses have gained recognition as significant regulators of microbial interactions within AD communities, yet their ecological roles remain largely unexplored. In this study, we investigated the ecological roles of AD viruses in regulating microbial interactions among syntrophic hosts. We recovered 3921 diverse viral sequences from four full-scale anaerobic digesters and confirmed their widespread presence across 127 global metagenomic sampling sites (with >95 % sequence similarity), underscoring the ubiquity of prokaryotic viruses in AD-related systems.
View Article and Find Full Text PDFWater Res
January 2025
Laboratory of Biomass Bio-chemical Conversion, Guang Zhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address:
Propionate is a key intermediate in anaerobic digestion (AD) under low operational temperatures, which can destabilize the process. In this study, the supplementation of syntrophic cold-tolerant consortia and trace elements significantly improved the performance of psychrophilic (20 °C) reactor, increasing methane production to 91 % of mesophilic reactor levels and reducing propionate concentrations to less than 2 % of those in untreated psychrophilic reactors. Multi-omics analyses revealed that psychrophilic conditions downregulated the methylmalonyl-CoA and aceticlastic methanogenesis pathways.
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