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Nature Microbiology Jan 2022
Topics: Anaerobiosis; Bacteria, Anaerobic; Cardiovascular Diseases; Gastrointestinal Microbiome; Humans
PubMed: 34949825
DOI: 10.1038/s41564-021-01009-4 -
Bioresource Technology Nov 2022Anaerobic treatment is applied as an alternative to traditional aerobic treatment for recalcitrant compound degradation. This review highlighted the recalcitrant... (Review)
Review
Anaerobic treatment is applied as an alternative to traditional aerobic treatment for recalcitrant compound degradation. This review highlighted the recalcitrant compounds in wastewaters and their pathways under aerobic and anaerobic conditions. Forty-one recalcitrant compounds commonly found in wastewater along with associated anaerobic removal performance were summarized from current research. Anaerobic degradability of wastewater could not be appropriately evaluated by BOD/COD ratio, which should only be suitable for determining aerobic degradability. Recalcitrant wastewaters with a low BOD/COD ratio may be handled by anaerobic treatments after the adaption and provision of sufficient electron donors. Novel indicator characterizing the anaerobic recalcitrance of wastewater is called for, essential for emergent needs to resource recovery from high-strength recalcitrant wastewater for fulfilling appeals of circular bioeconomy of modern societies.
Topics: Anaerobiosis; Bioreactors; Waste Disposal, Fluid; Wastewater
PubMed: 36087651
DOI: 10.1016/j.biortech.2022.127920 -
The Science of the Total Environment Jan 2021The extensive use of fossil fuels and the environmental effect of their combustion products have attracted researchers to look into renewable energy sources. In... (Review)
Review
The extensive use of fossil fuels and the environmental effect of their combustion products have attracted researchers to look into renewable energy sources. In addition, global mass production of waste has motivated communities to recycle and reuse the waste in a sustainable way to lower landfill waste and associated problems. The development of waste to energy (WtE) technology including the production of bioenergy, e.g. biogas produced from various waste through Anaerobic Digestion (AD), is considered one of the potential measures to achieve the sustainable development goals of the United Nations (UN). Therefore, this study reviews the most recent studies from relevant academic literature on WtE technology (particularly AD technology) for biogas production and the application of a solar-assisted biodigester (SAB) system aimed at improving performance. In addition, socio-economic factors, challenges, and perspectives have been reported. From the analysis of different technologies, further work on effective low-cost technologies is recommended, especially using SAB system upgrading and leveraging the opportunities of this system. The study found that the performance of the AD system is affected by a variety of factors and that different approaches can be applied to improve performance. It has also been found that solar energy systems efficiently raise the biogas digester temperature and through this, they maximize the biogas yield under optimum conditions. The study revealed that the solar-assisted AD system produces less pollution and improves performance compared to the conventional AD system.
Topics: Anaerobiosis; Biofuels
PubMed: 32889316
DOI: 10.1016/j.scitotenv.2020.141920 -
Journal of Environmental Management Aug 2021The debate on the relationship between the long-established concept of sustainability, and the relatively novel one of circularity in constantly increasing biogas... (Review)
Review
The debate on the relationship between the long-established concept of sustainability, and the relatively novel one of circularity in constantly increasing biogas production remains. In this study, additional discussion elements to such an open debate are provided. With its role in the bioeconomy and ongoing ambiguity, a bibliographic review of anaerobic digestion is provided. In particular, this study aims to i) verify whether sustainability assessments and circularity measurements are performed in different ways in anaerobic digestion projects and ii) understand which indicators have been utilized for each pillar of sustainability. Initially, 152 scientific documents from the Scopus and Web of Science scholarly journal databases were selected. Specific eligibility criteria that were any type of measurement of circularity and/or assessment of sustainability, were used for screening. Fifty-eight articles met these criteria and were analyzed in depth. The results show that the terms circularity and sustainability are not always univocal concepts in the reviewed scientific contributions. Consequently, the relative criteria or measurements for their analysis are not the same. As a result, a different interpretation of the two concepts is suggested. Circularity should be considered as one of the ways to achieve the broadest objective of sustainability.
Topics: Anaerobiosis; Biofuels
PubMed: 33962278
DOI: 10.1016/j.jenvman.2021.112695 -
Bioresource Technology Jan 2022Anaerobic digestion has been recognized as promising technology for bioenergy production, while the bottlenecks including long start up times, low methane contents, and... (Review)
Review
Anaerobic digestion has been recognized as promising technology for bioenergy production, while the bottlenecks including long start up times, low methane contents, and susceptibility toward environmental change attenuate the process benefits. Integrating microbials electrolysis cell (MEC) with anaerobic digestion (AD) has been recognized as a promising strategy for alleviate the performance bottleneck. This review summarized and updated the current researches that utilize MEC-AD for enhanced methane production from biomass. The integrated AD-MEC was first elucidated, followed by illustrations on strategies for process performance enhancements, parameters effects, and the associated applications. Finally, the challenges and prospects were outlined in this work.
Topics: Anaerobiosis; Biomass; Bioreactors; Electrolysis; Methane
PubMed: 34785334
DOI: 10.1016/j.biortech.2021.126321 -
Deutsches Arzteblatt International Nov 2019
Topics: Anaerobiosis; Comorbidity; Humans; Irritable Bowel Syndrome; Prevalence
PubMed: 31774055
DOI: 10.3238/arztebl.2019.0755a -
The Science of the Total Environment Oct 2021Zero valent iron (ZVI) has been used extensively to control environmental pollution owing to its strong reducibility and low cost. Herein, we evaluate the impact of ZVI... (Review)
Review
Zero valent iron (ZVI) has been used extensively to control environmental pollution owing to its strong reducibility and low cost. Herein, we evaluate the impact of ZVI (iron scrap and ZVI powder with different scales) on anaerobic digestion (AD) reactor performance improvement and syntrophic relationship stimulation among various microbial groups in the methanogenesis process. In recent studies, ZVI addition significantly enhanced methane and volatile fatty acid (VFA) yields and alleviated excessive acidification, ammonia accumulation, and odorous gas production. Further, we reviewed the changes in enzyme activity and microbial metabolism after the addition of ZVI throughout the reaction process. Certain innovative technologies, such as bioelectrochemical system assistance and combined usage of conductive materials, may improve AD performance compared to the use of ZVI alone, the mechanism of which has been discussed from various viewpoints. Furthermore, the primary technical bottlenecks, such as poor mass transfer efficiency in dry AD and high ZVI dosage, have been illustrated, and syntrophic methanogenesis regulated by ZVI addition can be further studied by conducting theoretical research.
Topics: Ammonia; Anaerobiosis; Fatty Acids, Volatile; Iron; Methane
PubMed: 34412392
DOI: 10.1016/j.scitotenv.2021.148415 -
Scientific Reports Aug 2021The effect of nanobubbles on anaerobic growth and metabolism of Pseudomonas aeruginosa was investigated. P. aeruginosa grew earlier in the culture medium containing...
The effect of nanobubbles on anaerobic growth and metabolism of Pseudomonas aeruginosa was investigated. P. aeruginosa grew earlier in the culture medium containing nanobubbles and the bacterial cell concentration in that culture medium was increased a few times higher compared to the medium without nanobubbles under anaerobic condition. Both gas and protein, which are the metabolites of P. aeruginosa, were remarkably produced in the culture medium containing nanobubbles whereas those metabolites were little detected in the medium without nanobubbles, indicating nanobubbles activated anaerobic growth and metabolism of P. aeruginosa. The carbon dioxide nanobubbles came to be positively charged by adsorbing cations and delivered ferrous ions, one of the trace essential elements for bacterial growth, to the microbial cells, which activated the growth and metabolism of P. aeruginosa. The oxygen nanobubbles activated the activities of P. aeruginosa as an oxygen source.
Topics: Anaerobiosis; Culture Media; Nanoparticles; Pseudomonas aeruginosa; Sterilization
PubMed: 34413439
DOI: 10.1038/s41598-021-96503-4 -
Bioresource Technology Mar 2020Anaerobic fungi (AF, phylum Neocallimastigomycota) are best known for their ability to efficiently break down lignocellulosic biomass. Their unique combination of... (Review)
Review
Anaerobic fungi (AF, phylum Neocallimastigomycota) are best known for their ability to efficiently break down lignocellulosic biomass. Their unique combination of mechanical and enzymatic attacks on recalcitrant plant structures bears great potential for enhancement of the anaerobic digestion (AD) process. Although scientists in this field have long agreed upon the potential of AF for biotechnology, research is only recently gaining traction. This delay was largely due to difficulties in culture-dependent and culture-independent analysis of those high-maintenance organisms with their still unknown complex growth requirements. In this review, we will summarize current research efforts on bioaugmentation with AF and further point out, how the lack of basic knowledge on AF nutritional needs hampers their implementation on an industrial scale. Through this, we hope to further kindle interest into basic research on AF in order to advance their stable integration into biotechnological processes.
Topics: Anaerobiosis; Biofuels; Biomass; Biotechnology; Fungi; Neocallimastigomycota
PubMed: 31926794
DOI: 10.1016/j.biortech.2019.122687 -
Bioresource Technology Jun 2022The unprecedented demand for seafood has resulted in land-based recirculating aquaculture systems (RAS), a highly intensive but sustainable fish farming method. However,... (Review)
Review
The unprecedented demand for seafood has resulted in land-based recirculating aquaculture systems (RAS), a highly intensive but sustainable fish farming method. However, intensification also results in concentrated waste streams of fecal matter and uneaten feed. Harvesting and processing vast quantities of fish also leads to the production of byproducts, further creating disposal challenges for fish farms. Recent research indicates that anaerobic digestion (AD), often used for waste treatment in agricultural and wastewater industries, may provide a viable solution. Limited research on AD of freshwater, brackish, and saline wastewater from RAS facilities and co-digestion of seafood byproducts has shown promising results but with considerable operational and process stability issues. This review discusses challenges to AD due to low solid concentrations, salinity, low carbon/nitrogen ratio, and high lipid content in the waste streams. Opportunities for recovering valuable biomolecules and nutrients through microbial treatment, aquaponics, microalgae, and polyhydroxyalkanoate production are also discussed.
Topics: Anaerobiosis; Aquaculture; Nitrogen; Seafood; Wastewater
PubMed: 35413421
DOI: 10.1016/j.biortech.2022.127144