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Showing 1 to 20 of 34 for “"Volatile fatty acid (VFA)"”.
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The Effects Of Ph On Enhanced Biological Phosphorus Removal (ebpr) With Propionic Acid As The Dominant Volatile Fatty Acid (vfa)
… They used synthetic wastewater rich in acetic acid. In this study, we used real wastewater and the dominant volatile fatty acid available to microorganisms was propionic acid in continuous EBPR system. It was found that lower anaerobic zone pH (6.5 vs. 7.2) reduced the anaerobic P release both …
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EVALUATION OF A METHOD TO MEASURE VOLATILE FATTY ACIDS AND GASES IN VITRO WITH MATHEMATICAL MODELING
… emissions are stoichiometrically linked with volatile fatty acid (VFA) profiles in ruminant animals. For example, a shift from acetate to propionate may decrease carbon dioxide (CO2) and hydrogen (H2) production, and in turn, decrease conversion of CO2 and H2 to methane. In vitro methods have …
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Evaluation of in vitro and in vivo equine microbial population shifts in response to colic conditions
… in order to investigate treatment effects on VFA and NH3 concentration, and pH following starvation or starch overload. This research indicated that total volatile fatty acid (VFA) concentration may be affected by treatment following starch overload. Additionally, branched chain VFA, and …
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Integration of Ruminal Volatile Fatty Acid Production Methods, Ruminal Fluid Sampling Techniques, and Mathematical Modeling
… simpler methods of measuring the rate of ruminal volatile fatty acid (VFA) production and a practical but effective way of sampling ruminal fluid. In experiment 1, an in vitro technique (procedure and mathematical approach) were developed to estimate ruminal VFA production in vivo. This method …
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A Comparative Study of Anaerobic Digestion Processes for Sewage Sludge
… plant included thermophilic anaerobic digestion, acid/gas phased digestion, and temperature phased anaerobic digestion. To obtain design data, a year long study was conducted using bench scale digestion systems operating at different solids retention times (SRT) and organic loading rates (OLR). …
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Harnessing <i>Haloferax mediterranei</i> for Bioplastic Production from Organic Waste
… pretreatment, and the needs for efficient volatile fatty acid (VFA) generation. Then, ex-situ VFA recovery from digestate was experimentally evaluated using hydrophobic deep eutectic solvents with omniphobic membranes, and kinetic-affinity relationships guided the separation design. To …
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Acid-phase and Two-phase Codigestion of FOG in Municipal Wastewater
Acidogenic codigestion of fats, oils, and greases (FOG) was studied at 37"C using suspended sludge digesters operated as sequencing batch reactors (SBRs). Volatile fatty acid (VFA) production was found to increase with larger FOG loading rates, although this increase was insignificant compared the …
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Effect of roughage to concentrate ratio on ruminal fermentation and protein degradability in dairy cows
… UP 30. Mean rumen ammonia nitrogen (N) and total volatile fatty acid (VFA) concentrations did not differ among cows receiving different treatments but, cows fed treatment UP 30 had a lower ruminal acetic acid:propionic acid (A:P) ratio compared to the other treatments. There were no differences in …
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Nutritional value of flat pea hay fed to sheep at different levels
… as proportion of flatpea increased. Total volatile fatty acid (VFA) and acetate concentration decreased linearly (P<.005) and propionate, isovalerate, and valerate levels increased linearly (P<.01) with increased proportions of flatpea hay. In experiment 2, 30 wether lambs were fed diets …
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Enhanced Biological Phosphorus Removal from Dairy Manure to Meet Nitrogen:Phosphorus Crop Nutrient Requirements
… nutrient management. The fermentation potential (volatile fatty acid (VFA) production) of dairy manure was determined through laboratory analysis to be 15.3% of the total COD. Total VFA production was composed of 57, 23, and 20% acetic, propionic, and butyric acids, respectively. The EBPR …
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Thermal Hydrolysis of LCFAs and Influence of pH on Acid-phase Codigestion of FOG
… and grease (FOG). The mechanisms of long chain fatty acids (LCFA) degradation in thermal hydrolysis pretreatment and the influence of pH on LCFA degradation in two-phase co-digestion systems were studied. LCFA thermal hydrolysis was investigated at different temperatures (90-250 °C) and reaction …
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Anaerobic Digestion: Factors Effecting Odor Generation
… the performance of anaerobic digesters (volatile solids reduction (VSR), residual biological activity (RBA) and effluent volatile fatty acid (VFA) content) also showed no correlation with odors. The second part of the study focused on determining the impact of anaerobic digester solids …
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The Utility of Culture Independent Methods to Evaluate the Fecal Microbiome in Overweight Horses Fed Orchard Grass Hay
… on diet digestibility, plasma and fecal volatile fatty acid (VFA) concentrations, and fecal bacterial abundance. Hay, fecal, and blood samples were taken daily for 4 days after a 10 day adaptation period. A difference in hay digestibility, fecal VFA concentration, or bacterial abundance …
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Effects of Annual and Perennial Forage Systems on Forage Biomass and Quality, Grazing Animal Performance and Enteric Emissions, and System Economics
… disappearance, greatest (P < 0.01) total volatile fatty acid (VFA) production (99 vs. 92 mmol d-1), and greatest (P< 0.01) ammonia-nitrogen (NH3-N) production (48.5 vs. 33.8 mg d-1). These fermentation parameters support improved growth performance in ruminants grazing annual forage …
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Biomethane production from grass silage: laboratory assessment to maximise yields
… system and recirculate rumen fluid to increase volatile fatty acid (VFA) and soluble chemical oxygen demand (SCOD) production whilst minimising volatile solids (VS) destruction. At times of high demand for electricity, connection of the UASB increases the destruction of volatiles and associated …
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Nutrient Impacts on Rumen Growth and Development
… was supported, but hypothesized changes in volatile fatty acid (VFA) transporter abundance and VFA absorption rate were not supported. These results indicate that form of diet, even one that promotes rumen growth, does not equate to enhanced ability to absorb VFA, but there is an effect on …
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Rapeseed, Sunflower and Soybean Meals as Protein Supplements in Dairy Calf Starters
… relationship between dietary protein and rumen volatile fatty acid (VFA) content</p>
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Longitudinal effects of early-life iron status in pigs
… ID pigs exhibited increased (P < 0.001) total volatile fatty acid (VFA) concentrations in ascending colon and rectal contents compared with CONT pigs at PND 32, but differences in VFA concentrations were absent after iron repletion. In ascending colon contents, 15 genera differed between ID and …
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Effects of Direct-Fed Microbial Products, Butyrate, and Botanicals on Performance and Health of Broilers Raised on Used Pine Shaving Litter
… lesion scores, body composition, and cecal volatile fatty acid (VFA) concentrations. The first experiment used a corn-soybean meal based basal diet to generate a negative control (NC) diet (without treatment), a Bacillus licheniformis probiotic containing diet (NC + 0.10% DFM1), and four …
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The feasibility and microbial community dynamics of using down flow hanging sponges (DHS) reactor in treating high strength soft drink wastewater
… be correlated with parameters like effluent pH, volatile fatty acid (VFA) concentrations and biomass content. Lower organic removal efficiency was correlated with lower pH and higher VFA concentration in the effluent. Higher organic removal efficiency was correlated to less suspended solid (SS) …
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