EFFECT OF SODIUM BICARBONATE ON RUMEN TURNOVER IN FREQUENTLY FED SHEEP

1983 ◽  
Vol 63 (3) ◽  
pp. 721-725 ◽  
Author(s):  
M. R. STOKES
Keyword(s):  
Fatty Acids ◽  
Sodium Bicarbonate ◽  
Key Words ◽  
Retention Time ◽  
Turnover Rate ◽  
Volatile Fatty Acids ◽  
Rumen Ph ◽  
Solids Retention Time ◽  
Solids Retention ◽  
Key Words Sodium

In four rumen-cannulated sheep fed 0, 1.5, 3.0 and 4.5% NaHCO3, the buffer increased rumen pH (P < 0.01) and isobutyrate (P < 0.10) but not rumen ammonia, lactate or other volatile fatty acids. Water intake increased (P < 0.01), liquid turnover rate varied quadratically (P < 0.09) and solids retention time and rumen solids volume varied cubically (P < 0.09 and P < 0.01) with NaHCO3 levels. Key words: Sodium bicarbonate, liquid turnover rate, solids retention time, sheep

Fundamental Studies on Hydrogen Production in the Acid-Forming Phase and Its Bacteria in Anaerobic Treatment Processes – The Effects of Solids Retention Time

1993 ◽  
Vol 28 (7) ◽  
pp. 81-88 ◽  
Author(s):  
Michimasa Nakamura ◽  
Hiroshi Kanbe ◽  
Jun'ichiro Matsumoto
Keyword(s):  
Retention Time ◽  
Volatile Fatty Acids ◽  
Anaerobic Bacteria ◽  
Anaerobic Treatment ◽  
Gas Production ◽  
Hydrogen Gas ◽  
Gas Content ◽  
Treatment Processes ◽  
Solids Retention Time ◽  
Solids Retention

Effects of solids retention time (SRT) on hydrogen gas production, glucose degradation and anaerobic bacteria in anaerobic treatment processes were investigated with use of 11,700 mg/l glucose solution as a substrate. Five series of experiments were conducted at 36 ± 1°C. Volatile fatty acids were produced in the order: acetic, n-butyric, propionic and n-valeric with concentration of effluent. Counts of general anaerobic bacteria and acid-forming bacteria in each reactor increased with increasing SRT, and counts of genus Clostridium and sulphate reducing bacteria in the reactor decreased with increasing SRT of the reactor. Gas production rates and gas composition were investigated to obtain information on energy production. Solids retention time increased from 2 to 10 h, hydrogen gas content decreased from 12 to 9%. The kinetic constants such as the microbial decay coefficient (Kd), the maintenance coefficient (m) and the growth yield for microorganisms (YG) were 4.04,41.7 and 0.097 day−1, respectively.

Study of the methanogenic degradation of phenol via carboxylation to benzoate

1991 ◽  
Vol 37 (7) ◽  
pp. 573-576 ◽  
Author(s):  
Jean-Guy Bisaillon ◽  
François Lépine ◽  
Réjean Beaudet
Keyword(s):  
Fatty Acids ◽  
Sodium Bicarbonate ◽  
Key Words ◽  
Yeast Extract ◽  
Volatile Fatty Acids ◽  
Bacterial Consortium ◽  
Proteose Peptone ◽  
Benzoate Degradation ◽  
Dead End ◽  
Cyclohexane Carboxylate

An anaerobic bacterial consortium carboxylating phenol to benzoate by cometabolism in the presence of proteose peptone under methanogenic conditions was studied. Yeast extract or a mixture of tryptophan and lysine could replace proteose peptone without affecting the carboxylating activity, whereas glucose, glycerol, pyruvate, volatile fatty acids, and sodium bicarbonate could not. The carboxylating microorganism could not be obtained pure from the phenol culture supplemented with tryptophan and lysine; six different morphological types of microorganisms were able to grow in this medium. The results obtained with potential intermediates of benzoate degradation given as substrates to the consortium suggest that benzoate is transformed to 1-cyclohexene carboxylate and to heptanoate. Part of 1-cyclohexene carboxylate was transformed to an apparent dead-end product identified as cyclohexane carboxylate. Key words: phenol, carboxylation, benzoate, methanogenic conditions.

scholarly journals Effect of time of supplementary feeding on intake, apparent digestibility and rumen fermentation of grass hay by sheep

1994 ◽  
Vol 59 (2) ◽  
pp. 217-222 ◽  
Author(s):  
M. D. Carro ◽  
A. R. Mantecón ◽  
I. A. Wright ◽  
I. J. Gordon
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Plasma Concentrations ◽  
Rumen Fermentation ◽  
Apparent Digestibility ◽  
Nonesterified Fatty Acids ◽  
Rumen Ph ◽  
Grass Hay ◽  
Forage Intake ◽  
Male Sheep

AbstractEffects of time of supplementation on forage intake, nutrient apparent digestibility and rumen fermentation were studied with 12 mature castrated male sheep (wethers) offered grass hay from 16.30 h to 09.30 h and supplemented with a cereal-based concentrate given at either 09.30 or 16.00 h. Voluntary intake of hay organic matter (OM) was decreased by feeding the concentrate (P< 0·01). Offering concentrate at 09.30 h after hay was available, increased intake of hay and total OM compared with offering it at 16.00 h before hay was available (P< 0·05). Daily pattern of hay intake was not changed when concentrate was offered at 09.30 h compared with feeding hay alone, but concentrate given at 16.00 h resulted in a lower hay intake between 16.30 and 18.00 h. Sheep offered concentrate at 09.30 h had higher rumen ammonia levels than those offered concentrate at 16.00 h, but there were no differences in the apparent digestibility of the nutrients, rumen pH and molar proportions of the main volatile fatty acids. There were also no differences between groups in the blood plasma concentrations of 3-hydroxybutyrate (30HB), nonesterified fatty acids (NEFA) and glucose. It is concluded that feeding supplement after rather than before a period of intake of forage or a bout of grazing may offer a means of minimizing reduction of forage intake as a consequence of feeding concentrate.

Impact of solids retention time on dissolved organic nitrogen and its biodegradability in treated wastewater

2016 ◽  
Vol 92 ◽  
pp. 44-51 ◽  
Author(s):  
Halis Simsek ◽  
Murthy Kasi ◽  
Jae-Bom Ohm ◽  
Sudhir Murthy ◽  
Eakalak Khan
Keyword(s):  
Retention Time ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Treated Wastewater ◽  
Solids Retention Time ◽  
Solids Retention

Nitrogen removal in activated sludge systems including denitrification in secondary clarifiers

1994 ◽  
Vol 30 (6) ◽  
pp. 101-111 ◽  
Author(s):  
H. Siegrist ◽  
W. Gujer
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Retention Time ◽  
Secondary Clarifier ◽  
Solids Retention Time ◽  
Solids Retention ◽  
Activated Sludge Systems

Denitrification in the secondary clarifier can contribute substantially to the nitrogen removal of activated sludge systems. This is illustrated on two treatment plants with different secondary clarifier systems. A model to estimate denitrification capacity and to design activated sludge systems for nitrogen removal is developed and verified with data from two treatment plants. The model includes denitrification in the secondary clarifier, wastewater composition (soluble readily biodegradable COD, particulate degradable COD), oxygen input into the anoxic volume, temperature, and solids retention time (SRT). The influence of aerated grit chambers and primary sedimentation on denitrification is discussed.

scholarly journals Volatile Fatty Acids and Biomethane Recovery from Thickened Waste Activated Sludge: Hydrothermal Pretreatment’s Retention Time Impact

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1580
Author(s):  
Farokh laqa Kakar ◽  
Ahmed El Sayed ◽  
Neha Purohit ◽  
Elsayed Elbeshbishy
Keyword(s):  
Fatty Acids ◽  
Activated Sludge ◽  
Retention Time ◽  
Volatile Fatty Acids ◽  
Oxygen Demand ◽  
Hydrothermal Pretreatment ◽  
Waste Activated Sludge ◽  
Optimum Conditions ◽  
Pretreatment Temperature ◽  
Biomethane Production

The main objective of this study was to evaluate the hydrothermal pretreatment’s retention time influence on the volatile fatty acids and biomethane production from thickened waste activated sludge under mesophilic conditions. Six different retention times of 10, 20, 30, 40, 50, and 60 min were investigated while the hydrothermal pretreatment temperature was kept at 170 °C. The results showed that the chemical oxygen demand (COD) solubilization increased by increasing the hydrothermal pretreatment retention time up to 30 min and stabilized afterwards. The highest COD solubilization of 48% was observed for the sample pretreated at 170 °C for 30 min. Similarly, the sample pretreated at 170 °C for 30 min demonstrated the highest volatile fatty acids yield of 14.5 g COD/Lsubstrate added and a methane yield of 225 mL CH4/g TCODadded compared to 4.3 g COD/Lsubstrate added and 163 mL CH4/g TCODadded for the raw sample, respectively. The outcome of this study revealed that the optimum conditions for solubilization are not necessarily associated with the best fermentation and/or digestion performance.

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