Effects of organic matter and initial carbon–nitrogen ratio on the bioconversion of volatile fatty acids from sewage sludge

2008 ◽  
Vol 83 (7) ◽  
pp. 1049-1055 ◽  
Author(s):  
Xiaoling Liu ◽  
He Liu ◽  
Yiyang Chen ◽  
Guochen Du ◽  
Jian Chen
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Sewage Sludge ◽  
Volatile Fatty Acids ◽  
Initial Carbon ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio

scholarly journals Sludge char-to-fuel approaches based on the hydrothermal fueling IV: fermentation

2021 ◽  
Author(s):  
Jinyi Qin ◽  
Rui Zhang ◽  
Ruiwen Yang ◽  
Jiao Fang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Organic Matter ◽  
Fatty Acid ◽  
Sewage Sludge ◽  
Acid Content ◽  
Saturated Fatty Acids ◽  
Fatty Acid Content ◽  
Heating Value ◽  
Cyclic Amino Acids

Abstract Sewage sludge was subjected to hydrothermal fueling (HTF) (330 °C for 40 min), obtaining hydrochar at 13.5 MJ kg−1. The higher heating value (HHV) of the raw sludge was related to its fatty acid content. The results showed that although the higher heating value (HHV) of the raw sludge was related to its fatty acid content, with the intensification of HTF, the increase in aliphatic/cyclic amino acids determined the production of HHV in the hydrochar. In order to increase the content of fatty acids and amino acids, the sludge was fermented. However, the Bacteroidetes consumed the organic matter too early, which was detrimental to the production of HHV. Therefore, appropriate sludge fermentation is recommended to restrict excessive Bacteroidetes proliferation, decompose lipids to saturated fatty acids, and convert proteins to aliphatic/cyclic amino acids to increase the efficiency of converting sludge to fuel.

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.

The Organic matter in heavy alkaline soils

1927 ◽  
Vol 17 (1) ◽  
pp. 1-11 ◽  
Author(s):  
A. F. Joseph ◽  
B. W. Whitfeild
Keyword(s):  
Organic Matter ◽  
Depth Distribution ◽  
Humus Content ◽  
Salt Content ◽  
Field Studies ◽  
Alkaline Soils ◽  
Bright Sunlight ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Different Sources

1. Sudan soils are very low in organic matter, the total organic carbon being usually less than 1 per cent. In the Gezira, the humus carbon is about 40 per cent, of that of the total.2. Humus preparations purified as far as possible could not be obtained ash-free. Specimens of humus from widely different sources contain nearly the same proportion of carbon.3. Humus solutions (in very dilute alkali) keep fairly well in the dark. They also keep in bright sunlight if air is excluded. The use of standard solutions for colorimetric purposes is justified if not kept too long.4. Field studies show that the humus content of good soil is greater than that of poor, and that there is a marked inverse connection between salt and humus content.5. The above conclusion does not apply to the depth distribution of these constituents. In the Gezira, the maximum humus content is found at the fourth foot and the maximum salt content is found at about the same depth.6. The total nitrogen content of the soils studied is low, usually about 0·03 per cent. About one-fifth of this is humus nitrogen, and the carbon-nitrogen ratio is about twelve to one.

The effects of varying the nitrogen, sulphur, and phosphorus content of organic matter on its decomposition

1960 ◽  
Vol 11 (3) ◽  
pp. 317 ◽  
Author(s):  
NJ Barrow
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Organic Compounds ◽  
Phosphorus Content ◽  
Nitrogen Supply ◽  
The Other ◽  
Organic Mixture ◽  
Carbon Nitrogen Ratio ◽  
Phosphorus Mineralization ◽  
Nitrogen Ratio

The decomposition of a mixture of organic compounds was studied by measuring the evolution of carbon dioxide, and changes in the concentration of ammonium, sulphate, and phosphate. In one experiment the nitrogen supply was varied by varying the proportion of glycine in the mixture of organic compounds; in another the sulphur supply was varied by varying the proportion of cysteine; and in a third the phosphorus supply was varied by varying the proportion of sodium ß-glycerophosphate. Mineralization of an element depended on the concentration of that element in the organic mixture. Mineralization of nitrogen did not occur until respiration had lowered the carbon/nitrogen ratio to about 5 and mineralization of sulphur did not occur until respiration had lowered the carbon/sulphur ratio to about 50. On the other hand mineralization of phosphorus occurred before the carbon/phosphorus ratio had been reduced to any consistent figure. This may not be a characteristic of phosphorus mineralization but may have been caused by suboptimal supply of nitrogen. Mineralization of an element also depended on the concentration of other elements and, in general, reduced supplies of one element caused increased mineralization of others.

scholarly journals Volatile Fatty Acids Production from Codigestion of Food Waste and Sewage Sludge Based on β-Cyclodextrins and Alkaline Treatments

Archaea ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xue Yang ◽  
Xiang Liu ◽  
Si Chen ◽  
Guangmin Liu ◽  
Shuyan Wu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Sewage Sludge ◽  
Food Waste ◽  
Bacterial Communities ◽  
Volatile Fatty Acids ◽  
Integrated Treatment ◽  
Hydrolysis Rate ◽  
Novel Technology ◽  
Initial Ph ◽  
Hydrolysis Of

Volatile fatty acids (VFAs) are preferred valuable resources, which can be produced from anaerobic digestion process. This study presents a novel technology using β-cyclodextrins (β-CD) pretreatment integrated alkaline method to enhance VFAs production from codigestion of food waste and sewage sludge. Experiment results showed that optimized ratio of food waste to sewage sludge was 3 : 2 because it provided adequate organic substance and seed microorganisms. Based on this optimized ratio, the integrated treatment of alkaline pH 10 and β-CD addition (0.2 g/g TS) performed the best enhancement on VFAs production, and the maximum VFAs production was 8631.7 mg/L which was 6.13, 1.38, and 1.57 times higher than that of control, initial pH 10, and 0.2 g β-CD/g TS treatment, respectively. Furthermore, the hydrolysis rate of protein and polysaccharides was greatly improved in integration treatment, which was 1.18–3.45 times higher than that of other tests. Though the VFAs production and hydrolysis of polymeric organics were highly enhanced, the primary bacterial communities with different treatments did not show substantial differences.

Production of propionic acid-enriched volatile fatty acids from co-fermentation liquid of sewage sludge and food waste using Propionibacterium acidipropionici

2013 ◽  
Vol 68 (9) ◽  
pp. 2061-2066 ◽  
Author(s):  
Xiang Li ◽  
Hui Mu ◽  
Yinguang Chen ◽  
Xiong Zheng ◽  
Jingyang Luo ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Sewage Sludge ◽  
Propionic Acid ◽  
Food Waste ◽  
Volatile Fatty Acids ◽  
Biological Nutrient Removal ◽  
Distribution Analysis ◽  
Propionibacterium Acidipropionici ◽  
Second Stage ◽  
Fermentation Liquid

Volatile fatty acids (VFA), derived from sludge fermentation, have been used as one effective carbon source for biological nutrient removal, especially favorable with VFA containing with high levels of propionic acid. In this paper, a new fermentation method was employed to significantly produce the propionic acid-enriched VFA from the co-fermentation liquid of sewage sludge and food waste: including (1) mixing food waste with sludge in the anaerobic digester (the first stage) and (2) separating the mixture, sterilizing the first stage liquid and fermenting it after inoculation with Propionibacterium acidipropionici (the second stage). The effect of the key parameters including pH, the mixing ratio of the food waste and sludge, fermentation time and temperature of the first stage on the propionic acid-enriched VFA production (the second stage) was individually discussed. By the molecular weight distribution analysis, the comparison of the solubilisation and hydrolysis process in difference parameters was fully elaborated. The optimal combination of the parameters was then obtained. Finally, the propionic acid-enriched VFA fermentation was successfully conducted in a semi-continuous reactor using the first stage liquid from the optimal condition.

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