Effect of aeration rate and waste load on evolution of volatile fatty acids and waste stabilization during thermophilic aerobic digestion of a model high strength agricultural waste

2005 ◽  
Vol 96 (6) ◽  
pp. 721-730 ◽  
Author(s):  
J OBETAUGWUANYI
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Agricultural Waste ◽  
High Strength ◽  
Aeration Rate ◽  
Aerobic Digestion ◽  
Waste Stabilization ◽  
Waste Load ◽  
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 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.

Effect of Aeration Rate on the Hydrolysis and Acidification of Waste Activated Sludge in Thermophilic Aerobic Conditions

2013 ◽  
Vol 664 ◽  
pp. 111-116
Author(s):  
Ya Nan Hou ◽  
Chun Xue Yang ◽  
Ai Juan Zhou ◽  
Ai Jie Wang
Keyword(s):  
Fatty Acids ◽  
Activated Sludge ◽  
Volatile Fatty Acids ◽  
Oxygen Demand ◽  
Ventilation Rate ◽  
Aeration Rate ◽  
Waste Activated Sludge ◽  
Digestion Process ◽  
Hydrolysis Process ◽  
Soluble Chemical Oxygen Demand

This study investigated the effect of aeration rates on the hydrolysis process of Waste Activated Sludge (WAS) with thermophilic aerobic microbes and explained by the change of solubilization of lipids, carbohydrates and proteins in sludge under different aeration rates (0.03 vvm, 0.05 vvm, 0.07 vvm, 0.09 vvm, 0.11 vvm). The results revealed that with the increase of aeration rate, the accumulation of volatile fatty acids (VFAs) in the treated sludge was decreased. Only 2 142 mg COD/L was accumulated at the ventilation rate of 0.11 vvm, while the highest accumulation which was 4 088 mg/L at the ventilation rate of 0.05 vvm. Further investigation showed that under optimal aeration rate which was 0.05 vvm, theromophilic aerobic microbes facilitated the organism hydrolysis and increased the biodegradability of WAS significantly. The concentration of carbohydrates was improved remarkably from 70 mg COD/L to 560 mg COD/L compared with the control (the process without aeration) at 65°C. Meanwhile, the concentration of protein was increased stably due to the high activity of protease, and reached the peak of 1 320 mg COD/L after 72h, then decline at the later period. The maximal soluble chemical oxygen demand (SCOD) was 5 600 mg/L and VFAs was 4 088 mg COD/L, which would be beneficial to the followed digestion process. Therefore, appropriate aeration is efficient to improve the accumulation of soluble organic matters and VFAs in WAS.

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
Sign in / Sign up

Export Citation Format

Share Document