Effect of digestion temperature and pH on treatment efficiency and evolution of volatile fatty acids during thermophilic aerobic digestion of model high strength agricultural waste

2005 ◽  
Vol 96 (6) ◽  
pp. 707-719 ◽  
Author(s):  
J UGWUANYI
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Agricultural Waste ◽  
High Strength ◽  
Treatment Efficiency ◽  
Aerobic Digestion ◽  
Thermophilic Aerobic Digestion

The optimization of the conversion of agricultural waste into volatile fatty acids under anaerobic conditions

2014 ◽  
Vol 69 (4) ◽  
pp. 187-193 ◽  
Author(s):  
M. A. Gladchenko ◽  
S. N. Gaydamaka ◽  
V. P. Murygina ◽  
S. D. Varfolomeev
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Agricultural Waste ◽  
Anaerobic Conditions

scholarly journals Development of an Optimised Chinese Dome Digester Enables Smaller Reactor Volumes; Pilot Scale Performance

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2213 ◽  
Author(s):  
Abiodun O. Jegede ◽  
Grietje Zeeman ◽  
Harry Bruning
Keyword(s):  
Fatty Acids ◽  
Ambient Temperature ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Pilot Scale ◽  
High Loading ◽  
Treatment Efficiency ◽  
Total Solids ◽  
Loading Rates ◽  
Volatile Solids

Chinese dome digesters are usually operated at long hydraulic retention times (HRT) and low influent total solids (TS) concentration because of limited mixing. In this study, a newly optimised Chinese dome digester with a self-agitating mechanism was investigated at a pilot scale (digester volume = 500 L) and compared with a conventional Chinese dome digester (as blank) at 15% influent TS concentration at two retention times (30 and 40 days). The reactors were operated at ambient temperature: 27–33 °C. The average specific methane production, volatile fatty acids and percentage of volatile solids (VS) reduction are 0.16 ± 0.13 and 0.25 ± 0.05L CH4/g VS; 1 ± 0.5 and 0.7 ± 0.3 g/L; and 51 ± 14 and 57 ± 10% at 40 days HRT (day 52–136) for the blank and optimised digester, respectively. At 30 days HRT (day 137–309) the results are 0.19 ± 0.12 and 0.23 ± 0.04 L CH4/g VS; 1.2 ± 0.6 and 0.7 ± 0.3 g/L; and 51 ± 9 and 58 ± 11.6%. Overall, the optimised digester produced 40% more methane than the blank, despite the high loading rates applied. The optimised digester showed superior digestion treatment efficiency and was more stable in terms of VFA concentration than the blank digester, can be therefore operated at high influent TS (15%) concentration.

scholarly journals Recovery of volatile fatty acids (VFA) from complex waste effluents using membranes

2013 ◽  
Vol 69 (3) ◽  
pp. 495-503 ◽  
Author(s):  
M.-P. Zacharof ◽  
R. W. Lovitt
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Butyric Acid ◽  
Volatile Fatty Acids ◽  
Agricultural Waste ◽  
Permeate Flux ◽  
Anaerobic Digesters ◽  
Waste Effluents

Waste effluents from anaerobic digesters of agricultural waste were treated with a range of membranes, including microfiltration and nanofiltration (NF), to concentrate volatile fatty acids (VFA). Microfiltration was applied successfully to produce sterile, particle-free solutions with a VFA concentration of 21.08 mM of acetic acid and 15.81 mM of butyric acid. These were further treated using a variety of NF membranes: NF270 (Dow Chemicals, USA), HL, DL, DK (Osmonics, USA) and LF10 (Nitto Denko, Japan), achieving retention ratios of up to 75%, and giving retentates of up to 53.94 mM of acetate and 28.38 mM of butyrate. DK and NF270 membranes were identified as the best candidates for VFA separation and concentration from these multicomponent effluents, both in terms of retention and permeate flux. When the effluents are adjusted to alkali conditions, the highest productivity, retention and flux were achieved at pH 7. At higher pH there was a significant reduction in flux.

scholarly journals A Multiproduct Biorefinery Approach for the Production of Hydrogen, Methane and Volatile Fatty Acids from Agricultural Waste

2020 ◽  
Vol 11 (10) ◽  
pp. 5239-5246 ◽  
Author(s):  
Edoardo Righetti ◽  
Simone Nortilli ◽  
Francesco Fatone ◽  
Nicola Frison ◽  
David Bolzonella
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Agricultural Waste ◽  
Pilot Scale ◽  
Two Stage ◽  
Anaerobic Process ◽  
Real Environment ◽  
Production Of Hydrogen

Abstract A pilot scale biorefinery platform for the treatment of agro-waste and the production of hydrogen, methane and volatile fatty acids was studied in real environment. The system adopted was a two stage anaerobic process where hydrogen and volatile fatty acids were produced in the first phase (fermentation) and methane in the second one (digestion). The study demonstrated the possibility to produce a biogas composed by hydrogen and methane (10% and 55%, respectively) while recovering volatile fatty acids. The yield for acids production was equivalent to 0.13 gVFA/gTVS (as COD) with acetate and butyrate as dominant observed species. Graphic Abstract

Eco-compatible biochar mitigates volatile fatty acids stress in high load thermophilic solid-state anaerobic reactors treating agricultural waste

2020 ◽  
Vol 309 ◽  
pp. 123366 ◽  
Author(s):  
Lingyu Meng ◽  
Li Xie ◽  
Toshikazu Suenaga ◽  
Shohei Riya ◽  
Akihiko Terada ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Solid State ◽  
Volatile Fatty Acids ◽  
Agricultural Waste ◽  
High Load ◽  
Anaerobic Reactors
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