scholarly journals PRODUCTION OF VOLATILE FATTY ACIDS (VFA) BY ANAEROBIC DIGESTION OF RICE STRAW/COW DUNG MIX IN BATCH AND FED-BATCH PROCESSES

2021 ◽  
Author(s):  
N. A. Mostafa
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Rice Straw ◽  
Volatile Fatty Acids ◽  
Batch Processes ◽  
Cow Dung ◽  
Fed Batch

scholarly journals A Preliminary Study of the Effect of Bioavailable Fe and Co on the Anaerobic Digestion of Rice Straw

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 577 ◽  
Author(s):  
Gabriele Mancini ◽  
Stefano Papirio ◽  
Piet Lens ◽  
Giovanni Esposito
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Rice Straw ◽  
Microbial Growth ◽  
Volatile Fatty Acids ◽  
Limiting Factor ◽  
Bioavailable Fraction ◽  
Essential Trace Elements ◽  
Biomethane Production ◽  
Preliminary Study

Rice straw is an abundant and sustainable substrate for anaerobic digestion (AD), but it is often deficient in essential trace elements (TEs) for proper microbial growth and metabolism. A lack of TEs leads to AD imbalances and suboptimal biogas yields. However, the total TE concentration is not a sufficient indicator of the amount of TEs available to the microorganisms. Therefore, this study investigated the degree of bioavailability of iron (Fe) and cobalt (Co) during the AD of rice straw, and correlated it to the biomethane yields and volatile fatty acids (VFAs) produced. When the two TEs were dosed at 205 µg Fe/g TS and 18 µg Co/g TS of rice straw, the biomethane production was approximately 260 mL CH4/g VS, i.e., similar to that obtained when Fe and Co were not added. Despite an increased bioavailable fraction of 23 and 48% for Fe and Co, respectively, after TEs addition, the AD performance was not enhanced. Moreover, VFAs did not exceed 250 mg HAc/L both in the presence and absence of added TEs, confirming no enhancement of the methanogenesis step. Therefore, the bioavailability of Fe and Co was not a limiting factor for the biomethane production at low total VFAs concentration.

Enhancement of volatile fatty acids production from rice straw via anaerobic digestion with chemical pretreatment

2015 ◽  
Vol 38 (8) ◽  
pp. 1623-1627 ◽  
Author(s):  
Gwon Woo Park ◽  
Ilgook Kim ◽  
Kwonsu Jung ◽  
Charles Seo ◽  
Jong-In Han ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Rice Straw ◽  
Volatile Fatty Acids ◽  
Chemical Pretreatment

Influence of hydrothermal pretreatment conditions, typology of anaerobic digestion system, and microbial profile in the production of volatile fatty acids from olive mill solid waste

2021 ◽  
Vol 9 (2) ◽  
pp. 105055
Author(s):  
Yasmim Arantes da Fonseca ◽  
Nayara Clarisse Soares Silva ◽  
Adonai Bruneli de Camargos ◽  
Silvana de Queiroz Silva ◽  
Hector Javier Luna Wandurraga ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Solid Waste ◽  
Volatile Fatty Acids ◽  
Hydrothermal Pretreatment ◽  
Microbial Profile ◽  
Olive Mill Solid Waste ◽  
Pretreatment Conditions ◽  
Olive Mill

Increasing 2 -Bio- (H2 and CH4) production from food waste by combining two-stage anaerobic digestion and electrodialysis for continuous volatile fatty acids removal

2021 ◽  
Vol 129 ◽  
pp. 20-25
Author(s):  
Gamal K. Hassan ◽  
Rhys Jon Jones ◽  
Jaime Massanet-Nicolau ◽  
Richard Dinsdale ◽  
M.M. Abo-Aly ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Food Waste ◽  
Volatile Fatty Acids ◽  
Two Stage ◽  
Ch4 Production

scholarly journals Control and estimation of anaerobic digestion processes using hydrogen and volatile fatty acids measurements

2018 ◽  
Vol 78 (10) ◽  
pp. 2027-2035 ◽  
Author(s):  
M. Sbarciog ◽  
G. Giovannini ◽  
R. Chamy ◽  
A. Vande Wouwer
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Hydrogen Concentration ◽  
Volatile Fatty Acids ◽  
Control Structure ◽  
Tight Control ◽  
Detailed Model ◽  
Control Scheme ◽  
Estimation And Control ◽  
And Control

Abstract The anaerobic digestion (AD) technology is widely used in the treatment of waste and wastewater. To ensure the treatment efficiency and to increase the production of biogas, which can be reused as a renewable energy source, a good understanding of the process and tight control are needed. This paper presents an estimation and control scheme, which can be successfully used in the operation of the AD process. The process is simulated by the ADM1 model, the most complex and detailed model developed so far to characterize AD. The controller and the observer, which provides estimates of the unmeasurable variables needed in the computation of the control law, are designed based on a simplified model developed in a previous work. Since it has been shown that hydrogen concentration is an accurate and fast indicator of process stability, it was chosen as controlled variable. Aside from the hydrogen concentration, the only measurement employed by the proposed control structure is the volatile fatty acids concentration. Simulation results prove the effectiveness of the proposed control structure.

Application of Methanobrevibacter acididurans in anaerobic digestion

2004 ◽  
Vol 50 (6) ◽  
pp. 109-114 ◽  
Author(s):  
D.V. Savant ◽  
D.R. Ranade
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Low Ph ◽  
Anaerobic Digesters ◽  
Hydrogenotrophic Methanogen ◽  
Distillery Wastewater ◽  
Acid Tolerant ◽  
Acidic Conditions

To operate anaerobic digesters successfully under acidic conditions, hydrogen utilizing methanogens which can grow efficiently at low pH and tolerate high volatile fatty acids (VFA) are desirable. An acid tolerant hydrogenotrophic methanogen viz. Methanobrevibacter acididurans isolated from slurry of an anaerobic digester running on alcohol distillery wastewater has been described earlier by this lab. This organism could grow optimally at pH 6.0. In the experiments reported herein, M. acididurans showed better methanogenesis under acidic conditions with high VFA, particularly acetate, than Methanobacterium bryantii, a common hydrogenotrophic inhabitant of anaerobic digesters. Addition of M. acididurans culture to digesting slurry of acidogenic as well as methanogenic digesters running on distillery wastewater showed increase in methane production and decrease in accumulation of volatile fatty acids. The results proved the feasibility of application of M. acididurans in anaerobic digesters.

scholarly journals Rapid Two Stage Anaerobic Digestion of Nejayote through Microaeration and Direct Interspecies Electron Transfer

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1614
Author(s):  
David Valero ◽  
Carlos Rico ◽  
Raul Tapia-Tussell ◽  
Liliana Alzate-Gaviria
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Uasb Reactor ◽  
Organic Load ◽  
Great Abundance ◽  
Conductive Material ◽  
Direct Interspecies Electron Transfer ◽  
Interspecies Electron Transfer ◽  
Granulated Activated Carbon

Corn is one of the main food products in Mexico. The elaboration of corn-derived products generates wastewater with a high organic load (nejayote). Anaerobic digestion is an indicated treatment for wastewater with high organic loads. The results of this study show that the application of microaeration in the hydrolysis-fermentative reactor increased the percentage of volatile fatty acids (VFA) available in the medium by 62%. The addition of a conductive material, such as granulated activated carbon (GAC), promotes DIET (Direct interspecies electrons transfer) in the methanogenic UASB reactor increasing the methane yield by 55%. Likewise, a great diversity of exoelectrogenic bacteria, with the ability to donate electrons DIET mechanisms, were developed in the GAC biofilm, though interestingly, Peptoclostridium and Clostridium (17.3% and 12.75%, respectively) were detected with a great abundance in the GAC biofilm. Peptoclostridium has not been previously reported as a participant in DIET process.

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