Volatile fatty acids production from sewage organic matter by combined bioflocculation and anaerobic fermentation

2015 ◽  
Vol 193 ◽  
pp. 150-155 ◽  
Author(s):  
Rungnapha Khiewwijit ◽  
Karel J. Keesman ◽  
Huub Rijnaarts ◽  
Hardy Temmink
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Volatile Fatty Acids ◽  
Anaerobic Fermentation

Nutritional studies with sheep fed conserved ryegrass. 2. Silage supplemented with dried grass or barley

1980 ◽  
Vol 94 (1) ◽  
pp. 219-227 ◽  
Author(s):  
C. G. Wernli ◽  
R. J. Wilkins
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Energy Demand ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Nitrogen Retention ◽  
High Rate ◽  
Physical Factors ◽  
Digestible Organic Matter ◽  
Nutritional Studies

SummaryGrass silage (21.0 % D.M.) was given ad libitum to sheep together with supplements of rolled barley, dried-grass pellets or dried-grass wafers at 12 and 25 g organic matter (OM)/kg0·75.Intake of silage was greater with supplement at 12 g/kg0·75 but total intake of OM and digestible organic matter (DOM) increased with increasing supplement. Intake of OM was higher with the pellet supplement than with other supplements. Intake of DOM, however, did not differ between the pellet and barley treatments, but was lower with wafers.Concentrations of ammonia and total volatile fatty acids and the molar proportions of butyric and higher volatile fatty acids were higher when silage was supplemented with barley than with dried grass. Mean rumen retention times of silage and of supplement were highest in the barley-supplemented treatments. Dried-grass wafers were retained longer than dried-grass pellets. Supplement treatments did not differ significantly for eating and ruminating times, rumen fluid volume and pH, digestion rate in the rumen and nitrogen retention.At the low supplement rate silage consumption may have been controlled by factors associated directly with the silage, whereas at the high rate intake was limited either by physical factors or by the potential energy demand of the animals.

Volatile fatty acids and sulfide in pressure mains

1995 ◽  
Vol 31 (7) ◽  
pp. 169-179 ◽  
Author(s):  
T. Hvitved-Jacobsen ◽  
K. Raunkjær ◽  
P. H. Nielsen
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Production Rate ◽  
Volatile Fatty Acids ◽  
Production Rates ◽  
Net Production ◽  
Toc Removal ◽  
Sulfide Production ◽  
Transformation Of Organic Matter ◽  
High Sulfide

The main objective was to study the anaerobic transformation of organic matter and sulfide production during wastewater transportation. Emphasis was on the transformation of easily biodegradable organic matter in terms of volatile fatty acids (VFA). Samples from two intercepting pressure mains located in the Northern part of Jutland, Denmark, were taken. The concentration of VFA in the wastewater varied considerably during day and night, being typically between 5 and 50 g/m3. A net production as well as a net removal of VFA was seen during transportation in the pressure mains probably depending on the quality and quantity of the organic matter. Typically 85% of the VFA was acetate and 10% propionate; the remainder was formate, n-butyrate and iso-butyrate. Observed sulfide production rates from the sewer biofilms were typically 0.05 and 0.005 g S/m2 h at 12 and 4 °C, respectively. A high sulfide production rate corresponded with a high VFA concentration. TOC removal was observed in the pressure mains.

Effect of a Cellulose-Degrading Strain on Anaerobic Fermentation of Corn Straw

2011 ◽  
Vol 356-360 ◽  
pp. 2510-2514 ◽  
Author(s):  
Ming Fen Niu ◽  
Sai Yue Wang ◽  
Wen Di Xu ◽  
An Dong Ge ◽  
Hao Wang
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Corn Straw ◽  
High Efficient ◽  
Important Significance ◽  
Strong Capacity

In order to improve the rate of degradation of cellulose in corn straw, the study has an important significance that compost corn straw with inoculating high-efficient microbe agents. The experiment inoculated a cellulose-degrading strain F2 which was screened from compost into compost pretreatment, the VS of corn straw reduced from 93.14% to 71.69% after 15 days, the content of cellulose reduced from 34.12g·kg-1 to 25.66g·kg-1, the rate of degradation was 24.79% which was 10.60% higher than those without the strain. An anaerobic fermentation experiment was carried out with the two groups of composted corn straw and mixed pig feces with a certain ratio, and investigations of biogas production, pH, content of volatile fatty acids(VFA) and rate of methane production were conducted. The results were that the corn straw composted with the cellulose-degrading strain peaked 4 days earlier, the maximal daily biogas production was 1470mL, the cumulative biogas production reached 23641mL which was 16.87% higher and operated stably earlier. The study showed that the cellulose-degrading strain had a strong capacity to degrade cellulose in corn straw, and then improved the performance of anaerobic digestion.

Volatile fatty acids production from marine macroalgae by anaerobic fermentation

2012 ◽  
Vol 124 ◽  
pp. 500-503 ◽  
Author(s):  
Thi Nhan Pham ◽  
Woo Joong Nam ◽  
Young Joong Jeon ◽  
Hyon Hee Yoon
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Anaerobic Fermentation ◽  
Marine Macroalgae
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