Inhibition Effects of Inorganic and Polymer Coagulants on Acidogenic Fermentation

2007 ◽  
Vol 544-545 ◽  
pp. 79-82 ◽  
Author(s):  
Jong Oh Kim ◽  
Jong Tae Jung
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Protein Content ◽  
Ultrasonic Treatment ◽  
Volatile Fatty Acids ◽  
Carbohydrate Content ◽  
Laboratory Scale ◽  
Batch Experiments ◽  
Acidogenic Fermentation ◽  
Synthetic Sludge

Laboratory-scale batch experiments were conducted to investigate the possible inhibition of acidogenic volatile fatty acids (VFAs) fermentation by an inorganic and a polymer coagulant. It was found that the conversion from organic matter to VFAs decreased more than 10% when the dosages of coagulant exceeded 46 (mgAl/L) and 120 (mgFe/L). Inhibition by Al was greater than that Fe. When the dosage of polymer was over 102 (mg/L), VFAs conversion fell to below 2%. The protein content was more affected than the carbohydrate content. Ultrasonic treatment increased the VFAs conversion for synthetic sludge at both treated with either inorganic coagulant or polymer

Volatile fatty acids in the rumen of African sheep given a variety of low-protein diets

1964 ◽  
Vol 6 (1) ◽  
pp. 91-96 ◽  
Author(s):  
J. H. Topps ◽  
R. C. Elliott
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Acetic Acid ◽  
Protein Content ◽  
Volatile Fatty Acids ◽  
Acid Mixture ◽  
Ruminal Fermentation ◽  
Low Protein ◽  
Protein Diets ◽  
Total Concentrations

SUMMARY1. Total concentrations of volatile fatty acids and molar proportions of acetic, nrooionic and butyric acids were determined in the rumen of Blackhead Persian sheep given sixteen low-protein diets.2. Total concentrations of acids ranged from 2·89 to 9·33 millimoles/ 100 ml. of rumen liquor. Both digestibility and protein content of the ration had a significant effect on the concentration of volatile fatty acids in the rumen liquor. Protein content of the diet probably influenced the latter through controlling the rate of ruminal fermentation.3. Molar proportions of acetic acid varied from 59·7% to 69·3%, of propionic acid from 21·2% to 29·6%, and of butyric plus higher acids from 7·6% to 16·3%. Protein content of the diet had no significant effect on the composition of the acid mixture, but organic matter digestibility was inversely related to the proportion of acetic acid.4. The fermentation in the rumen of Blackhead Persian sheep, as judged by the volatile fatty acids produced, appears to be similar to that found in European breeds of sheep.

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.

Salinity induced acidogenic fermentation of food waste regulates biohydrogen production and volatile fatty acids profile

Fuel ◽  
2020 ◽  
Vol 276 ◽  
pp. 117794 ◽  
Author(s):  
Omprakash Sarkar ◽  
John Kiran Katari ◽  
Sulogna Chatterjee ◽  
S. Venkata Mohan
Keyword(s):  
Fatty Acids ◽  
Food Waste ◽  
Volatile Fatty Acids ◽  
Biohydrogen Production ◽  
Fatty Acids Profile ◽  
Acidogenic Fermentation

Production of polyhydroxyalkanoates by glycogen accumulating organisms treating a paper mill wastewater

2008 ◽  
Vol 58 (2) ◽  
pp. 323-330 ◽  
Author(s):  
Simon Bengtsson ◽  
Alan Werker ◽  
Thomas Welander
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Dry Weight ◽  
Paper Mill ◽  
Batch Experiments ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Pha Production ◽  
Paper Mill Wastewater ◽  
Enrichment Strategy

A process for production of polyhydroxyalkanoates (PHA) by activated sludge treating a paper mill wastewater was investigated. The applied strategy was to select for glycogen accumulating organisms (GAOs) by alternating anaerobic/aerobic conditions. Acidogenic fermentation was used as pretreatment to convert various organic compounds to volatile fatty acids which are preferable substrates for PHA production. Enrichment resulted in a culture dominated by GAOs related to Defluviicoccus vanus (56%) and Candidatus Competibacter phosphatis (22%). Optimization of PHA accumulation by the enriched GAO culture was performed through batch experiments. Accumulation of PHA under anaerobic conditions was limited by the intracellular glycogen stored. Under aerobic conditions significant glycogen production (to 25% of sludge dry weight) was observed alongside PHA accumulation (to 22% of sludge dry weight). By applying a subsequent anaerobic period after an initial aerobic, the produced glycogen could be utilized for further PHA accumulation and by this strategy PHA content was increased to 42% of sludge dry weight. The PHA yield over the entire process was 0.10 kg per kg of influent COD treated which is similar to what has been achieved with a process applying feast/famine enrichment strategy with the same wastewater.

Digestion by ruminant lambs of a diet containing formaldehyde-treated casein

1971 ◽  
Vol 22 (3) ◽  
pp. 461 ◽  
Author(s):  
GJ Faichney ◽  
RH Weston
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Plasma Levels ◽  
Volatile Fatty Acids ◽  
Amino Nitrogen ◽  
Ammonia Nitrogen ◽  
Casein Diet ◽  
Plasma Urea ◽  
Urea Level

Digestion of a diet containing 10% casein, either untreated or treated with formaldehyde, was studied in crossbred wether lambs. The treatment prevented breakdown of the casein in rumen liquor in vitro. There was a highly significant decrease in organic matter digestion in the rumen when the treated casein diet was given to the lambs. This was accounted for by increases in the amounts of protein and starch passing to the intestines. There was a 60 % increase in the amount of non-ammonia nitrogen and a 55 % increase in the amount of starch digested in the intestines. The concentrations of volatile fatty acids and ammonia in the rumen were significantly lower. There were increases in the plasma levels of insulin and �-amino nitrogen and a decrease in the plasma urea level in response to the treatment.

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