scholarly journals Colour removal and the effect of reactive dyes on acid producing anaerobic microorganisms

2011 ◽  
Vol 46 (3) ◽  
pp. 211-218 ◽  
Author(s):  
Debraj Bhattacharyya ◽  
Kripa S. Singh
Keyword(s):  
Fatty Acid ◽  
Organic Carbon ◽  
Toxic Effect ◽  
Volatile Fatty Acid ◽  
Reactive Dyes ◽  
Production Potential ◽  
Colour Removal ◽  
Anaerobic Microorganisms ◽  
Soluble Organic Carbon ◽  
Anaerobic Acidification

The cultures from a sucrose-fed anaerobic acid reactor were dosed with 0, 60, 100, 200, 400, 800 and 1,500 mg/L, of a mixture of three Procion reactive dyes, Red MX-8B, Red MX-5B and Orange MX-2R, in order to study the colour removal and the toxic effect of the dyes on anaerobic acidification of sucrose. Sucrose undergoes a possible extracellular transformation into intermediate substances before being taken up by the acidogens for volatile fatty acid (VFA) synthesis. The rate and the extent of this uptake is unaffected by the presence of dyes. The dyes, however, reduced the rate of synthesis of VFA, and considerably diminished the VFA production potential of sucrose. The acidification stopped, likely due to an inhibition caused by VFA accumulation. As a result, only 50–60% of the soluble organic carbon was utilised for VFA synthesis. The removal of colour by the unacclimated anaerobic acidogenic biomass takes place by adsorption. However, Freundlich's adsorption constants did not suggest a favourable adsorption.

Volatile fatty acid production in aerobic thermophilic pre-treatment of primary sludge

1997 ◽  
Vol 36 (11) ◽  
pp. 189-196 ◽  
Author(s):  
K. B. McIntosh ◽  
J. A. Oleszkiewicz
Keyword(s):  
Fatty Acid ◽  
Flow Rate ◽  
Volatile Fatty Acid ◽  
Volatile Fatty Acids ◽  
Final Concentration ◽  
Anoxic Condition ◽  
Fatty Acid Production ◽  
Primary Sludge ◽  
Soluble Organic Carbon ◽  
Pre Treatment

The efficiency of volatile fatty acid (VFA) production in a thermophilic aerobic digester (TAD) process using primary sludge was studied under two oxygenation states and detentions times ranging from 12 to 24 hours. The highest VFA concentration increase occurred in the 18 hour anaerobic aerated digester (O2 flow rate: 0.025 m3/m3·h; ORP: less than -300 mV) from 0.047 mg HAc/mg VSS in the feed to 0.106 mg HAc/mg VSS in the effluent. The anoxic condition (O2 flow rate: 0.14 m3/m3·h; ORP: between 0 to -225 mV) resulted in VFA utilisation and a final concentration of only 0.001 mg HAc/mg VSS. Under the anaerobic aerated condition, acetic acid constituted the largest fraction of short chain volatile fatty acids at an average of 60.4% and propionic trailed at 19.3%. The fraction of butyric and valeric acids were 12.2% and 8.1% respectively. It was found that with a decreasing oxygen supply and a decreasing detention time (HRT), the soluble organic carbon to ammonia ratio (SOC:NH3) increased.

Anaerobic acidification of a synthetic wastewater in batch reactors at 55°C

2002 ◽  
Vol 46 (11-12) ◽  
pp. 153-157 ◽  
Author(s):  
H.Q. Yu ◽  
H.H.P. Fang
Keyword(s):  
Fatty Acid ◽  
Substrate Concentration ◽  
Volatile Fatty Acid ◽  
Biomass Yield ◽  
Oxygen Demand ◽  
Dairy Wastewater ◽  
Synthetic Wastewater ◽  
Batch Reactors ◽  
Production Of Hydrogen ◽  
Anaerobic Acidification

Experiments were conducted to study the acidogenesis of a dairy wastewater in batch reactors at pH 5.5 and 55°C. There was a biased fermentation sequence for carbohydrate and protein, and the protein fermentation was delayed by carbohydrate. The production of hydrogen was exclusively from the fermentation of carbohydrate. Acetate and butyrate concentrations both increased rapidly at the beginning and peaked at some points, then declined in the reactors fed with 8 g-COD (chemical oxygen demand)/l, or higher concentrations. Butanol and propanol fractions increased with the substrate concentration. The metabolism shifted from the volatile fatty acid-producing pathways to the alcohol-producing pathways when the substrate concentration increased beyond 8 g-COD/l. The acidogenic biomass yield was in the range 0.19-0.25 mg-VSS/mg-COD.

scholarly journals Biogas and volatile fatty acid production during anaerobic digestion of straw, cellulose, and hemicellulose with analysis of microbial communities and functions

2020 ◽  
Author(s):  
Jie Liu ◽  
Xiaoyu Zuo ◽  
Ke Peng ◽  
Rui He
Keyword(s):  
Acetic Acid ◽  
Fatty Acid ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acid ◽  
Biogas Production ◽  
Raw Materials ◽  
Methane Content ◽  
Production Potential ◽  
Aceticlastic Methanogenesis ◽  
Stable Stage

Abstract Background Anaerobic digestion (AD) is a promising method for straw treatment, but the complex composition and structure of straw limit AD efficiency and methane production. The main biodegradable components of straw are cellulose and hemicellulose. Because of the different chemical structures and physicochemical properties, the performance of AD of cellulose and hemicellulose is different, thus it’s also different from that of straw. Research on the similarities and differences of AD of straw, cellulose and hemicellulose is helpful to clarify the law of anaerobic digestion of straw and provide theoretical basis for further improving the efficiency of anaerobic digestion. However, there are very few studies on AD using cellulose and hemicellulose as raw materials. Results Rice straw (RS), cellulose, and hemicellulose were used as raw materials to study biogas production performance and changes in the volatile fatty acids (VFAs). Further, microbial communities and genetic functions were analyzed separately for each material. The biogas production potential of RS, cellulose, and hemicellulose was different, with cumulative biogas production of 620.64, 412.50, and 283.75 mL/g·VS− 1, respectively. The methane content of the biogas produced from cellulose and hemicellulose was approximately 10% higher than that produced from RS after the methane content stabilized. Biogas production and the methane content of RS stabilized more quickly than that of cellulose and hemicellulose. The accumulation of VFAs occurred in the early stage of anaerobic digestion in all the three materials, and the main volatile fatty acid component of RS was acetic acid, whereas that of cellulose and hemicellulose was propionic acid. The cumulative amount of VFAs in both cellulose and hemicellulose was relatively higher than that in RS, and the accumulation time was 12 and 14 days longer, respectively. When anaerobic digestion progressed to a stable stage, Clostridium was the dominant bacterial genus in all three AD systems, and the abundance of Ruminofilibacter was higher during anaerobic digestion of RS. Genetically, AD of all the three materials proceeded mainly via aceticlastic methanogenesis, with similar functional components. Conclusion The biogas and VFAs production during AD of RS, cellulose, and hemicellulose showed marked differences. But when the AD progressed to the stable stage, there was no significant difference in microbial community and genetic function. Specifically, the biogas production potential of cellulose and hemicellulose was greater than that of RS. The accumulation of VFAs in the three AD systems occurred in the early stages. The main component of VFA that accumulated in RS was acetic acid, while the major component of VFAs accumulated in cellulose and hemicellulose digestions was propionic acid. At the stable stage, Clostridium was the dominant bacterial genus in all three AD systems. The AD of all the three materials proceeded mainly via aceticlastic methanogenesis, with similar components of gene functions.

Rumen Metabolite of Balinese Cows that Being Given Stewed Water of Lannea coromandelica Peel as Feed Additive

2017 ◽  
Vol 3 (5) ◽  
pp. 24 ◽  
Author(s):  
Sio Stefanus ◽  
I.G. Mahardika ◽  
I.B.G Partama ◽  
N.N. Suryani
Keyword(s):  
Acetic Acid ◽  
Fatty Acid ◽  
Rice Bran ◽  
Volatile Fatty Acid ◽  
Gliricidia Sepium ◽  
Feed Additive ◽  
Random Design ◽  
Lannea Coromandelica

The research has been conducted to find out rumen metabolite of Balinese cows that being given stewed water of Lannea coromandelica peel as a feed additive. The research used group random design (RAK) with 4 treatments of rations and 3 times repetition. Each repetition used three Balinese cows. The weight of cows being used ranging between 137.5 – 235 kg. Basic rations being given were equal, arranged based on a percentage of dry material (% DM) namely: 50% of arrow grass, 20% of gamal leaves (Gliricidia sepium), 1% of urea and 29% of rice bran. Whereas for treatment was feed additive level. The basic ratio of +0 was feed additive (A). The basic ration of +1000 ml was feed additive (B). The basic ration of +1500 ml was feed additive (C) and a basic ration of +2000 ml was feed additive (D). Variables being observed were: N-NH3, volatile fatty acid total and volatile fatty acid partial (acetic acid, propionate acid and butyrate acid). The result of research showed that the administration of 1000 ml-2000 ml of feed additive of stewed water of Lannea coromandelica peel in basic ration differed markedly (P<0.05) to increase the concentration of N-NH3, volatile fatty acid total and volatile fatty acid partial. The utilization of stewed water of Lannea coromandelica peel as a feed additive in basic ration was increasing rumen metabolite of Balinese cows.

Sign in / Sign up

Export Citation Format

Share Document