Bacterial decimation times in anaerobic digestions of animal slurries

Olsen, John Elmerdahl; Larsen, Holger Errebo

doi:10.1016/0269-7483(87)90121-2

Cited by 87 publications

(14 citation statements)

References 10 publications

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“…However, it should be realized that heat-resistant pathogens including Bacillus cereus, Erysopelotrix rhusiopathiae, Listeria monocytogene, Staphylococcus aureus, Streptococcus faecalis, Yersinia enterocolitica, C. perfringens spores etc. were hardly removed by mesophilic and thermophilic AD or composting (Elmerdahl Olsen and Errebo Larsen, 1987;Kearney et al, 1993a). Therefore, it appears that high temperature should not be always regarded as a guaranty of high ARGs removal.…”

Section: Temperaturementioning

confidence: 99%

Is anaerobic digestion a reliable barrier for deactivation of pathogens in biosludge?

Zhao

Liu

2019

Science of The Total Environment

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Editor: Huu Hao NgoAs World Health Organization advocates, the global burden of sanitation related disease and access to safely managed sanitation and safely treated wastewater should be monitored strictly. However, the spread of pathogens through various agricultural applications or direct discharge of sewage sludge generated in municipal wastewater treatment plants poses a serious challenge on the environment and public health. Anaerobic digestion (AD), the principal method of stabilizing biosolids, can efficiently and largely deactivate viable pathogens, including parasite, virus, and the pathogens harboring antibiotic resistance genes. This review aims to provide a critical overview regarding the deactivation of sludge-associated pathogens by AD, through which a serious concern on the effectiveness and rationality of AD towards sludge pathogens control was raised. Meanwhile, the underlying deactivation mechanisms and affecting factors were all discussed, with the focus on pathogen-associated modeling, engineering design and technological aspects of AD. Lastly, a matric method incorporating the operating strategy of AD with the risk assessment was proposed for evaluating the reliability of AD-based pathogen deactivation, while the research agenda forward was also outlined.

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Section: Temperaturementioning

confidence: 99%

Is anaerobic digestion a reliable barrier for deactivation of pathogens in biosludge?

Zhao

Liu

2019

Science of The Total Environment

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“…Digestion taking place at higher temperatures requires less time for bacterial inactivation and this causes bacteria to die much faster under thermophilic rather than mesophilic digestion [26]. It was already demonstrated by Olsen and Larsen [27] in a study including Salmonella typhimurium, Salmonella dublin, E. coli, Staphylococcus aureus, Streptococcus faecalis, Erysopelotrix rhusiopathiae, Bacillus cereus, and Clostridium perfringens. Salmonella, and M. paratuberculosis which were inactivated within 24 h under thermophilic anaerobic digestion compared to weeks and even months under mesophilic anaerobic digestion.…”

Section: Resultsmentioning

confidence: 92%

Pathogen Reduction Potential in Anaerobic Digestion of Organic Fraction of Municipal Solid Waste and Food Waste

et al. 2020

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Anaerobic digestion (AD) is a commonly used method of processing waste. Regardless of the type of the used digestate (fertilizer, feedstock in case of solid-state fermentation, raw-material in case of thermal treatment) effective pathogen risk elimination, even in the case of high pathogen concentration is essential. An investigation of the survival time and inactivation rate of the Salmonella Senftenberg W775, Enterococcus spp., and Ascaris suum eggs during thermophilic anaerobic digestion performed on laboratory scale and confirmation of hygienization in full-scale operation were performed in this study. Except for sanitization efficiency, the AD process performance and stability were also verified based on determination of pH value, dry matter content, acidity, alkalinity, and content of fatty acids. The elimination of pathogen was met within 6.06 h, 5.5 h, and about 10 h for the Salmonella Senftenberg W775, Enterococcus spp., and Ascaris suum, respectively in the laboratory trials. The obtained results were confirmed in full-scale tests, using 1500 m3 Kompogas® reactors, operating in MBT Plant located in Poland. Sanitization of the digestate was achieved. Furthermore, the process was stable. The pH value, suspended solids, and ammonium content remained stable at 8.5, 35%, and 3.8 g/kg, respectively. The acetic acid content was noted between almost 0.8 and over 1.1 g/kg, while the concentration of propionic acid was noted at maximum level of about 100 mg/kg. The AD conditions could positively affect the pathogen elimination. Based on these results it can be found that anaerobic digestion under thermophilic conditions results in high sanitation efficiency.

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“…Residual CH 4 should not disturb SCP production and may even be used in a separate O 2 -dependent SCP production step involving the established SCP methanotroph Methylococcus capsulatus. Spores of pathogens may potentially be carried in the gas phase, but this risk can be addressed by two measures: first, anaerobic digestion, in particular thermophilic AD, is known to deactivate pathogens and spores contained in biowastes to some extent [82]. Second, remaining levels of spores can be filtered with commercial filters [83].…”

Section: Sources Of Substrates and Nutrientsmentioning

confidence: 99%

Agriculture-independent, sustainable, fail-safe and efficient food production by autotrophic single-cell protein

Bogdahn¹

2015

Preprint

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Food production with plants consumes large amounts of water, occupies large areas of land and cannot guarantee food security beyond the 21st century. Industrial agriculture in particular, is destructive to the environment, fosters climate change in profound ways, deteriorates public health and causes high "hidden costs". Single-cell protein (SCP) represents an alternative with minimal carbon-, water-and land footprints. However, when grown on biowastes of industrial agriculture, heterotrophic SCP does not truly improve sustainability or food security.This hypothesis paper proposes autotrophic SCP bioprocess designs which enable sustainable, fail-safe and efficient production of edible biomass from CO 2 and N 2 or NH 3 . They can be driven by H 2 , CO or HCOOH from several sustainable sources. Besides H 2 O-electrolysis and syngas, surprisingly fossil fuels may provide an effectively carbon-negative and cheap supply of H 2 through the decomposition of CH 4 or oil. Most promising bioprocess designs consist of 2-stages. In the 1 st stage, homoacetogenic bacteria fix CO 2 up to 10 more efficiently than plants, and secrete it as acetate. In the 2 nd stage, selected microbes grow on the acetate and thereby form edible biomass. Bacteria have unique features including N 2 -fixation, H 2 S tolerance and O 2 -tolerant hydrogenases for fast lightindependent growth. Eukaryotic microalgae are already approved as food and exhibit oxygenic photosynthesis which partly replaces solar-panels, seawater desalination and H 2 O-electrolyzers. Photoheterotrophic growth on acetate decouples these benefits from inefficient endogenous CO 2 fixation. Slow gas mass-transfer, poor light distribution and expensive cell harvest are major challenges arising from the cultivation in liquid media. To cope with this, microbes grow as hydrated biofilms that are exposed directly to substrate gases, and that can be dry-harvested. Two suitable bioreactors are presented and adaptations for 2-stage designs are proposed. Since provision with substrates is expensive, two strategies are proposed for the safe extraction of substrates from food-grade as well as non-food-grade biowastes via partial anaerobic digestion. Additionally, alkalic pH and hydroxides formed at the cathode during electrolysis may be used to precipitate CO 2 from the air as carbonates. In two use cases, 2-stage designs with solar-powered H 2 -generation from seawater were estimated to exceed productivity of wheat 20-200 fold, for moderate and arid climates respectively. Preliminary cost estimates and data about direct and indirect subsidies of industrial agriculture lead to the hypothesis that autotrophic SCP likely outperforms industrial agriculture not only in ecological but also in economical aspects.

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Bacterial decimation times in anaerobic digestions of animal slurries

Cited by 87 publications

References 10 publications

Is anaerobic digestion a reliable barrier for deactivation of pathogens in biosludge?

Is anaerobic digestion a reliable barrier for deactivation of pathogens in biosludge?

Pathogen Reduction Potential in Anaerobic Digestion of Organic Fraction of Municipal Solid Waste and Food Waste

Agriculture-independent, sustainable, fail-safe and efficient food production by autotrophic single-cell protein

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