scholarly journals Building of Mini Bio Gas Plant Using Anaerobic Digestion of Organic Compounds

2017 ◽  
Vol 4 (1) ◽  
pp. 150-155
Keyword(s):  
Anaerobic Digestion ◽  
Organic Compounds

scholarly journals Effect of organic compounds on dry anaerobic digestion of food and paper industry wastes

Bioengineered ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 502-509
Author(s):  
Anette T. Jansson ◽  
Regina J. Patinvoh ◽  
Mohammad J. Taherzadeh ◽  
Ilona Sárvári Horváth
Keyword(s):  
Anaerobic Digestion ◽  
Organic Compounds ◽  
Paper Industry ◽  
Dry Anaerobic Digestion

Enhanced solubilisation of the residual fraction of municipal solid waste

2008 ◽  
Vol 57 (7) ◽  
pp. 995-1000 ◽  
Author(s):  
D. G. Cirne ◽  
V. B. Agbor ◽  
L. Björnsson
Keyword(s):  
Anaerobic Digestion ◽  
Organic Compounds ◽  
Methane Production ◽  
Waste Incineration ◽  
The Other ◽  
Residual Fraction ◽  
Cellulolytic Enzymes ◽  
Digestion Time ◽  
Two Stage ◽  
Digestion Process

The Swedish ordinance banning the landfilling of organic material after 2005 has led to rapid developments towards waste incineration, while biological alternatives have been less studied. In this study, biological alternatives for enhanced methane production from residual municipal waste (the remaining waste fraction after source separation) are investigated. The strategies investigated were recirculation of leachate, recirculation of leachate with aeration, flooding of the solid bed, and enzyme addition after initial leaching in an anaerobic, batch, two-stage digestion process with recirculation of digested leachate. The degree of solubilisation of organic compounds achieved was higher for initial digestion in a two-stage anaerobic digestion system followed by the addition of cellulolytic enzymes than in the other strategies investigated. The overall net solubilisation achieved was 0.48 g COD/g VSadded corresponding to an increase of 34%. In addition, the digestion time was considerably reduced using this strategy. For the other strategies investigated the solubilisation yields obtained were similar, 0.31 g COD/g VSadded.

Anaerobic digestion of C1–C4 light oxygenated organic compounds derived from the torrefaction of lignocellulosic materials

2015 ◽  
Vol 131 ◽  
pp. 150-158 ◽  
Author(s):  
Shi-Shen Liaw ◽  
Craig Frear ◽  
Wayne Lei ◽  
Shuai Zhang ◽  
Manuel Garcia-Perez
Keyword(s):  
Anaerobic Digestion ◽  
Organic Compounds ◽  
Lignocellulosic Materials

scholarly journals Effects of sludge properties in a combined process of mesophilic anaerobic digestion and thermophilic aerobic digestion

2020 ◽  
Vol 194 ◽  
pp. 04015
Author(s):  
Zehua Zhao ◽  
Yuanshun Xu ◽  
Tianfeng Wang ◽  
Xiaowei Xu ◽  
Houhu Zhang ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Organic Compounds ◽  
Retention Time ◽  
Capillary Water ◽  
Extracellular Polymers ◽  
Aerobic Digestion ◽  
Conventional Activated Sludge ◽  
Sludge Stabilization ◽  
Sludge Properties ◽  
Thermophilic Aerobic Digestion

The combination of mesophilic anaerobic digestion and thermophilic aerobic digestion (MAN-TAD) has been recognized as a suitable technology to deal with conventional activated sludge. The MAN-TAD system can make sludge achieve better stability. The retention time of anaerobic digestion (AD-time) had an important role in the sludge stabilization process. With the extension of anaerobic digestion retention time, MAN-TAD system can make sludge achieve better stability. In comparison, volatile/total solids ratio (VS/TS) at AD-time of 38 d presented the lowest values among the three different AD-time with the value of 0.32. Long retention time of anaerobic digestion resulted in high amounts of soluble organic compounds (SCOD), and extracellular polymers (EPS) in the supernatant. Such high amount of organic compounds caused deterioration in sludge dewaterability. Compared with sludges of AD-time 17 d and 24 d, sludge of AD-time 38 d became extremely difficult to dewater due to its high capillary water absorption time (CST) at the end of digestion.

scholarly journals Effectiveness of Scenedesmus sp. Biomass Grow and Nutrients Removal from Liquid Phase of Digestates

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1432 ◽  
Author(s):  
Marta Kisielewska ◽  
Marcin Zieliński ◽  
Marcin Dębowski ◽  
Joanna Kazimierowicz ◽  
Zdzisława Romanowska-Duda ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Organic Compounds ◽  
Growth Medium ◽  
Ammonia Nitrogen ◽  
Phosphorus Concentration ◽  
Limiting Factor ◽  
Cultivation Medium ◽  
Initial Concentration ◽  
Liquid Digestate ◽  
Microalgae Biomass

One of the most important factors in determining the profitable production of microalgae biomass is the use of a cost effective growth medium that is rich in nutrients. The objective of the study was to determine the possibility of using digestates from anaerobic digestion of different feedstock mixtures as the media for Scenedesmus sp. cultivation. A different liquid digestate composition was obtained in terms of organic compounds, phosphorus, and nitrogen concentrations, depending on the substrates used in the anaerobic digestion. It was found that the highest biomass production was obtained when using digestate from anaerobic digestion of the feedstock mainly composed of microalgae biomass, which was characterized by low organic compounds concentration. In this case, the average biomass concentration reached 2382 mg total solids/L. A lower Scenedesmus sp. biomass yield was obtained using digestate from anaerobic digester processing feedstock based on maize silage and cattle menure. In the variants of the study, it was also found that the increase in the initial concentration of ammonia nitrogen in the growth medium up to 160 mg/L significantly reduced the growth of Scenedesmus sp. The results indicated the possibility of a high ammonia nitrogen and orthophosphates removal from anaerobic digestates by Scenedesmus sp. microalgae. Phosphorus concentration in the cultivation medium is a limiting factor for the growth of Scenedesmus sp., thus phosphorus supplementation should be considered when using liquid digestate as the culture medium. The optimization model indicated that the volume of liquid digestate that was used for preparing the cultivation medium, the initial concentration of organic compounds, and the initial concentration of ammonia nitrogen had a significant impact on the production of Scenedesmus sp. biomass.

scholarly journals The Effects of Halogenated Compounds on the Anaerobic Digestion of Macroalgae

Fermentation ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 85
Author(s):  
Birthe V Nielsen ◽  
Supattra Maneein ◽  
Md Mahmud Al Farid ◽  
John J Milledge
Keyword(s):  
Anaerobic Digestion ◽  
Organic Compounds ◽  
Dry Weight ◽  
Environmental Chemicals ◽  
Aerobic Biodegradation ◽  
Halogenated Hydrocarbons ◽  
Strictly Anaerobic ◽  
Terrestrial Plants ◽  
Halogenated Compounds ◽  
Halogenated Organic Compounds

The urgent need to replace fossil fuels has seen macroalgae advancing as a potential feedstock for anaerobic digestion. The natural methane productivity (dry weight per hectare) of seaweeds is greater than in many terrestrial plant systems. As part of their defence systems, seaweeds, unlike terrestrial plants, produce a range of halogenated secondary metabolites, especially chlorinated and brominated compounds. Some orders of brown seaweeds also accumulate iodine, up to 1.2% of their dry weight. Fluorine remains rather unusual within the chemical structure. Halogenated hydrocarbons have moderate to high toxicities. In addition, halogenated organic compounds constitute a large group of environmental chemicals due to their extensive use in industry and agriculture. In recent years, concerns over the environmental fate and release of these halogenated organic compounds have resulted in research into their biodegradation and the evidence emerging shows that many of these compounds are more easily degraded under strictly anaerobic conditions compared to aerobic biodegradation. Biosorption via seaweed has become an alternative to the existing technologies in removing these pollutants. Halogenated compounds are known inhibitors of methane production from ruminants and humanmade anaerobic digesters. The focus of this paper is reviewing the available information on the effects of halogenated organic compounds on anaerobic digestion.

Odor control during post-digestion processing of biosolids through bioaugmentation of anaerobic digestion

2008 ◽  
Vol 57 (4) ◽  
pp. 589-594 ◽  
Author(s):  
N. Tepe ◽  
D. Yurtsever ◽  
M. Duran ◽  
R. J. Mehta ◽  
C. Bruno ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Propionic Acid ◽  
Organic Compounds ◽  
Dimethyl Sulfide ◽  
Methyl Mercaptan ◽  
Odor Control ◽  
Short Term ◽  
Term Study ◽  
Short Term Study ◽  
Average Residual

The effects of bioaugmenting anaerobic biosolids digestion with a commercial product that contained selected strains of bacteria from genera Bacillus, Pseudomonas, and Actinomycetes, along with ancillary organic compounds containing various micronutrients were evaluated. The main objective of the study was to investigate the effects of bioaugmentation specifically on the performance of methanogenesis during anaerobic digestion, as well as on the generation and fate of odor-causing compounds during the storage of the digested biosolids. The bench-scale digester with 5 g/L bioaugment generated 29% more net CH4 than a control during the eight weeks of operation. In addition, the average residual propionic acid concentration in the bioaugmented digester was 46% lower than that in the control. The biosolids digested in the bioaugmented digester generated a negligible amount of methyl mercaptan (CH3SH) during 10 days of post-digestion storage, while CH3SH concentration in the control reached nearly 300 ppmv during the same period. Similarly peak dimethyl sulfide (CH3SCH3) generated by stored biosolids from the bioaugmented digester was only 37% of that from the control. Similar results were obtained in a subsequent short term study designed to confirm the repeatability of the findings.

The Tempo and mode(S) of Prebiotic Evolution

1997 ◽  
Vol 161 ◽  
pp. 419-429 ◽  
Author(s):  
Antonio Lazcano
Keyword(s):  
Origin Of Life ◽  
Organic Compounds ◽  
Biological Evolution ◽  
Current Evidence ◽  
Early Diversification ◽  
Time Period ◽  
The Galaxy ◽  
History Of ◽  
Widespread Phenomenon ◽  
The Origin Of Life

AbstractDifferent current ideas on the origin of life are critically examined. Comparison of the now fashionable FeS/H2S pyrite-based autotrophic theory of the origin of life with the heterotrophic viewpoint suggest that the later is still the most fertile explanation for the emergence of life. However, the theory of chemical evolution and heterotrophic origins of life requires major updating, which should include the abandonment of the idea that the appearance of life was a slow process involving billions of years. Stability of organic compounds and the genetics of bacteria suggest that the origin and early diversification of life took place in a time period of the order of 10 million years. Current evidence suggest that the abiotic synthesis of organic compounds may be a widespread phenomenon in the Galaxy and may have a deterministic nature. However, the history of the biosphere does not exhibits any obvious trend towards greater complexity or «higher» forms of life. Therefore, the role of contingency in biological evolution should not be understimated in the discussions of the possibilities of life in the Universe.

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