Volatile fatty acids production from food waste: Effects of pH, temperature, and organic loading rate

Abstract This paper addresses the production of volatile fatty acids with fermentation of whey permeate under acidogenic conditions. The coal-immobilized biomass of an anaerobic fluidized bed reactor operated with a fairly constant hydraulic residence time of 12 min transformed the substrate (whey permeate i.e., essentially lactose) into a blend of acetic, propionic, butyric and isobutyric acids corresponding to between 2 and 19, 1 and 6, 11 and 30, 0 and 2% of the initial load (carbon basis), respectively. There was a slight decrease in the sugar transformation efficiency (65 to 48%) with the increase of the organic loading rate (OLR) which varied from 586 to 3339 g sugar/Lreactord. At the highest OLR of 3339 g sugar/Lreactor.d, the biomass transformed 19% of the substrate into a blend of acetic, propionic, butyric and isobutyric acids. Residual sugar and bio-gas were 52 and 2%, respectively, of the initial load (carbon basis). Cet article fait référence L une étude sur la production d’acides gras volatiles par fermentation anaérobie du perméat de lactosérum dans un bioréacteur. La biomasse fixée aux grains de charbon composant le lit fluidisé, opérant avec un temps de rétention hydraulique de 12 minutes, transformait le substrat (perméat i.e., essentiellement lactose) en un mélange d’acide acétique, propionique, n-butyrique et isobutyrique correspondant respectivement L 2 et 19, 1 et 6, 11 et 30, 0 et 2% de la charge initiale (sur la base d’un bilan de carbone). Il a été possible d’observer une légère diminution de l’efficacité de la biodégradation du sucre (65 L 48%) avec une augmentation du taux de charge organique lequel variait de 586 L 3 339 g de sucre/Lréacteurd. L la charge organique la plus forte, soit 3 339 g de sucre/Lréacteur.d, la biomasse transformait le substrat L 19% en un mélange d’acide acétique, propionique, n-butyrique et isobutyrique. La part du sucre résiduel était de 52% et celle du biogaz L 2% (bilan de carbone).

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Influence of Organic Loading Rate on the Process Imbalance of Anaerobic Digestion with Food Waste

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.733.419 ◽

2015 ◽

Vol 733 ◽

pp. 419-422

Author(s):

Bing Mei ◽

Xu Ya Peng

Keyword(s):

Anaerobic Digestion ◽

Food Waste ◽

Volatile Fatty Acids ◽

Loading Rate ◽

Organic Loading Rate ◽

Organic Loading ◽

Stirred Tank Reactors ◽

Process Indicators ◽

Reliable Parameter ◽

Biogas Reactors

The use of volatile fatty acids (VFAs) as process indicators in biogas reactors treating Food Waste (FW) was studied. The aim of this work was to determine a reliable parameter which could be used as an indicator of process imbalance during anaerobic digestion of FW in the continuously stirred tank reactors (CSTR) anaerobic reactor. It can be concluded from this that not only VFAs concentrations are indicator for process imbalance during anaerobic digestion of FW, but also VFAs changes constitute the most important indicators of early warning of process imbalances.

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Volatile fatty acids production from cheese whey: influence of pH, solid retention time and organic loading rate

Journal of Chemical Technology & Biotechnology ◽

10.1002/jctb.5549 ◽

2018 ◽

Vol 93 (6) ◽

pp. 1742-1747 ◽

Cited By ~ 8

Author(s):

Rolando Rafael Calero ◽

Borja Lagoa-Costa ◽

María Mercedes del Coro Fernandez-Feal ◽

Christian Kennes ◽

Maria Carmen Veiga

Keyword(s):

Fatty Acids ◽

Retention Time ◽

Volatile Fatty Acids ◽

Cheese Whey ◽

Loading Rate ◽

Organic Loading Rate ◽

Organic Loading ◽

Solid Retention Time ◽

Influence Of Ph

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The Adaptation of Anaerobic Granulated Bed to Changes in Loading Rate and Liquid Upflow Velocity in UASB Reactors

Water Quality Research Journal ◽

10.2166/wqrj.1989.032 ◽

1989 ◽

Vol 24 (4) ◽

pp. 523-536 ◽

Cited By ~ 3

Author(s):

N. Kosaric ◽

R. Blaszczyk ◽

L. Orphan

Keyword(s):

Fatty Acids ◽

Feed Rate ◽

Volatile Fatty Acids ◽

Loading Rate ◽

Organic Loading Rate ◽

Organic Loading ◽

Uasb Reactors

Abstract Four 20L UASB reactors, R1, R2, R3 and R4 were operated at different upflow velocities of 0.25, 1.0, 1.5, and 0.5 m/h, respectively. Changes in loading rate were achieved by removing part of granules from the bed at a constant volumetric feed rate of 6.2 g COD/(L day). It was found that the granulated bed may adapt to the increased organic loading rate up to about 1.6 kg COD/(kg VSS day) and achieve a 100% conversion of the COD present (composed of volatile fatty acids). Increasing the loading rate over the above value can bring about a decreased COD conversion. At the organic loading rate of 1.6 kg COD/(kg VSS day), the accumulation of granules in reactors R1 and R4 was observed. At the same loading rate, no accumulation of granules was observed in reactor R2 (within 40 days) and in reactor R3 (within 55 days). It was also found that a great number of large granules were washed out from reactors R1 and R4 when the loading rate of about 0.7 kg COD/(kg VSS day) was maintained for about 70 days.

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Specialized trace elements and volatile fatty acids interactions for enhanced methane production and biomethanization process stability during high organic loading rate

Nigerian Journal of Biotechnology ◽

10.4314/njb.v38i1.21 ◽

2021 ◽

Vol 38 (1) ◽

pp. 179-193

Author(s):

N.C. Ezebuiro ◽

I. Körner

Keyword(s):

Fatty Acids ◽

Trace Elements ◽

Methane Production ◽

Volatile Fatty Acids ◽

Loading Rate ◽

Total Alkalinity ◽

Organic Loading Rate ◽

Organic Loading ◽

Ch4 Production ◽

Volatile Organic

Volatile fatty acids (VFAs) and trace elements (TEs) interactions (VFAs*TEs) during biomethanization have effects that could be exploited to enhance anaerobic digestion (AD) of biomass. The goal of this study was to validate biocatalytic effects of specialized VFAs*TEs identified from a batch-derived Optimum TEs Configuration (or simply ‘Optimum’) on high organic loading rate (OLR) involving mixed fruit residue (MFR) fed in semi-continuous AD operation. The specialized VFAs*TEs were formulated as Variants of the Optimum and included Optimum –Cobalt (Co) for specialized VFAs*Co effects, and Optimum +Selenium (Se) for specialized VFAs*Se effects. Four duplicate AD reactors were treated with formulations reflecting the Optimum and the Variants. Each duplicate reactor was semi-continuously fed with MFR at varying OLR until instability occurred. Methane production, total volatile organic acidity (FOS) / total alkalinity (TAC) and VFAs fingerprints were measured as main responses. The results showed that reactors of the Optimum and its Variants were unstable at OLR of 8g oDM/L/d, but stability was restored in the Optimum –Co (FOS/TAC values of 0.6 compared to 1.51 and 1.67 for Optimum and Optimum +Se respectively). The average specific CH4 production (Nml/g oDM) of the Optimum and its Variants were Control: 431±36; Optimum: 553±16; Optimum –Co: 580±12; and Optimum +Se: 545±13. Optimum –Co also had the lowest acetic acid and butyric acid accumulation, but had higher propionic acid concentration (0.7 g/L) compared to the Optimum (0.3 g/L) and Optimum +Se (0.4 g/L).

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Effects of temperature and organic loading rate on the performance and microbial community of anaerobic co-digestion of waste activated sludge and food waste

Chemosphere ◽

10.1016/j.chemosphere.2014.01.018 ◽

2014 ◽

Vol 105 ◽

pp. 146-151 ◽

Cited By ~ 103

Author(s):

Chengliu Gou ◽

Zhaohui Yang ◽

Jing Huang ◽

Huiling Wang ◽

Haiyin Xu ◽

...

Keyword(s):

Microbial Community ◽

Activated Sludge ◽

Food Waste ◽

Loading Rate ◽

Organic Loading Rate ◽

Waste Activated Sludge ◽

Organic Loading ◽

Effects Of Temperature

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Adjusting Organic Load as a Strategy to Direct Single-Stage Food Waste Fermentation from Anaerobic Digestion to Chain Elongation

Processes ◽

10.3390/pr8111487 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1487

Author(s):

Vicky De Groof ◽

Marta Coma ◽

Tom C. Arnot ◽

David J. Leak ◽

Ana B. Lanham

Keyword(s):

Anaerobic Digestion ◽

Food Waste ◽

Loading Rate ◽

Biogas Production ◽

Single Stage ◽

Stirred Tank ◽

Chain Elongation ◽

Organic Loading Rate ◽

Organic Loading ◽

Operating Strategy

Production of medium chain carboxylic acids (MCCA) as renewable feedstock bio-chemicals, from food waste (FW), requires complicated reactor configurations and supplementation of chemicals to achieve product selectivity. This study evaluated the manipulation of organic loading rate in an un-supplemented, single stage stirred tank reactor to steer an anaerobic digestion (AD) microbiome towards acidogenic fermentation (AF), and thence to chain elongation. Increasing substrate availability by switching to a FW feedstock with a higher COD stimulated chain elongation. The MCCA species n-caproic (10.1 ± 1.7 g L−1) and n-caprylic (2.9 ± 0.8 g L−1) acid were produced at concentrations comparable to more complex reactor set-ups. As a result, of the adjusted operating strategy, a more specialised microbiome developed containing several MCCA-producing bacteria, lactic acid-producing Olsenella spp. and hydrogenotrophic methanogens. By contrast, in an AD reactor that was operated in parallel to produce biogas, the retention times had to be doubled when fed with the high-COD FW to maintain biogas production. The AD microbiome comprised a diverse mixture of hydrolytic and acidogenic bacteria, and acetoclastic methanogens. The results suggest that manipulation of organic loading rate and food-to-microorganism ratio may be used as an operating strategy to direct an AD microbiome towards AF, and to stimulate chain elongation in FW fermentation, using a simple, un-supplemented stirred tank set-up. This outcome provides the opportunity to repurpose existing AD assets operating on food waste for biogas production, to produce potentially higher value MCCA products, via simple manipulation of the feeding strategy.

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