The effect of moisture content and alkalinity on the anaerobic biodegradation of VIP contents

2008 ◽  
Vol 58 (2) ◽  
pp. 473-477 ◽  
Author(s):  
A. A.-L. Couderc ◽  
C. A. Buckley ◽  
K. Foxon ◽  
C. F. Nwaneri ◽  
B. F. Bakare ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Moisture Content ◽  
Anaerobic Biodegradation ◽  
Gas Production ◽  
Buffering Capacity ◽  
Limiting Factors ◽  
Production Rates ◽  
Serum Bottle ◽  
Ph Buffering ◽  
Ph Buffering Capacity

This study investigated the effect of additional moisture and/or alkalinity on the rate of anaerobic digestion in samples of material obtained from pit latrines. In modified serum bottle tests it was shown that poor gas production rates were observed from all experiments with material collected at the lower part of one pit. Using material from the top layer of a second pit it was shown that experimental bottles produced significant amounts of gas with both the addition of water and the addition of alkalinity. The results supports the motivating hypotheses that moisture content and pH buffering capacity obtained in VIP material are low and may be limiting factors in the rate of stabilisation that may occur in these pits. This implies that increasing the moisture content and alkalinity in the pit has the potential to increase stabilisation rate in the pit when the material is not already well-stabilised.

The effect of moisture content and alkalinity on the anaerobic biodegradation of pit latrine sludge

2008 ◽  
Vol 58 (7) ◽  
pp. 1461-1466 ◽  
Author(s):  
A. A.-L. Couderc ◽  
K. Foxon ◽  
C. A. Buckley ◽  
C. F. Nwaneri ◽  
B. F. Bakare ◽  
...  
Keyword(s):  
Moisture Content ◽  
Gas Production ◽  
Low Ph ◽  
Limiting Factor ◽  
Production Rates ◽  
Serum Bottle ◽  
Ph Buffering ◽  
Discernible Effect ◽  
Pit Latrine ◽  
Biological Stabilisation

This study investigated the effect of additional moisture and/or alkalinity on the rate of anaerobic digestion in samples of material obtained from pit latrines. In modified serum bottle tests it was shown that poor gas production rates were observed from all experiments with material collected at the lower part of one pit. Using material from the top layer of a second pit it was shown that experimental bottles produced significant amounts of gas for all treatments. Analysis of data indicated that treatment with additional alkalinity had no discernible effect on anaerobic gas production rates, but that there was some correlation between moisture content and gas production rate. These results did not support the hypothesis that low pH buffering capacity was a limiting factor in the rate of digestion of pit latrine sludge, but confirmed that low moisture content could reduce the rate of stabilisation. This implies that increasing the moisture content in a pit latrine has the potential to increase biological stabilisation rates in the pit when the material is not already well-stabilised.

Mapping Soil pH Buffering Capacity of Selected Fields in the Coastal Plain

2004 ◽  
Vol 68 (2) ◽  
pp. 662-668 ◽  
Author(s):  
A. R. Weaver ◽  
D. E. Kissel ◽  
F. Chen ◽  
L. T. West ◽  
W. Adkins ◽  
...  
Keyword(s):  
Soil Ph ◽  
Coastal Plain ◽  
Buffering Capacity ◽  
Ph Buffering ◽  
Ph Buffering Capacity

scholarly journals Correlation between pH, buffering capacity, calcium and dental caries in schoolchildren

2018 ◽  
Vol 63 (01) ◽  
pp. 63-68
Author(s):  
Efka Zabokova Bilbilova ◽  
Ana Sotirovska Ivkovska ◽  
Olivera Sarakinova ◽  
Olga Kokoceva Ivanovska ◽  
Natasha Stavreva
Keyword(s):  
Dental Caries ◽  
Free Group ◽  
Buffer Capacity ◽  
Saliva Sample ◽  
Buffering Capacity ◽  
Active Group ◽  
Ph Buffering ◽  
Ph Values ◽  
Salivary Ph ◽  
Ph Buffering Capacity

The aim of this study was to determine salivary pH, buffering capacity and calcium levels in caries-free and caries-active children. We examined 80 children of both genders, 15 years of age. Subjects were divided into four groups as follows: caries-free females, caries-active females, caries-free males, caries-active males; each group consisted of 20 subjects. The unstimulated saliva sample was collected by the spitting method and then pH, buffering capacity and calcium in saliva was measured. The results showed that mean level of buffering capacity of saliva was decreased significantly in the caries-active group as compared to caries-free group. The obtained data showed that the mean levels of pH and calcium were decreased in the caries-active group as compared to the caries-free group, but the difference was not statistically significant. The saliva with its constituents plays an important role in maintaining oral and especially dental health. Salivary pH values were found to be higher in the caries-free group. In our study, there was no significant correlation of pH values and caries activity with gender. Buffer capacity values were significantly lower in the caries-active group than in the caries-free group. There were significant differences when the groups were compared in the caries-active group where buffer capacity values were higher in boys than in girls. Calcium content of saliva was higher in the caries-free group. The results obtained in this study related to the values of the pH, buffering capacity and calcium in saliva, may serve as parameters for determining the caries risk patients, and accordingly to plan and carry appropriate caries preventive measures. Keywords: saliva, dental caries, pH, buffer capacity, calcium

scholarly journals Effects of Refining Parameters on the Properties of Oil Palm Frond (OPF) Fiber for Medium Density Fibreboard (MDF)

2021 ◽  
Vol 87 (3) ◽  
pp. 64-77
Author(s):  
Zawawi Ibrahim ◽  
Aisyah Humaira Alias ◽  
Ridzuan Ramli ◽  
Noorshamsiana Abdul Wahab ◽  
Mansur Ahmad ◽  
...  
Keyword(s):  
Oil Palm ◽  
Bonding Strength ◽  
Medium Density Fiberboard ◽  
Steam Pressure ◽  
Buffering Capacity ◽  
Medium Density ◽  
Ph Buffering ◽  
Oil Palm Frond ◽  
Palm Frond ◽  
Ph Buffering Capacity

Studies on the manufacture of medium density fiberboard (MDF) from oil palm frond (OPF) fibre were conducted to provide a sustainable and feasible source of lignocellulosic materials. The quality and properties of the fibre are very important as it dictates the final MDF properties. The properties of fibre like fibre pH, buffering capacity, and morphology can influence most of the MDF performances. Refining condition is one of the most important factors which determine the properties of the refined fibre. In this study, the effects of different refining pressures and temperatures on OPF fibre were evaluated. The refining of OPF fibre was observed at four levels of refining parameters; which were categorized as low (2 bar at 130 °C), medium (4 bar at 150 °C), high (6 bar at 170 °C), and severe (8 bar at 190 °C). The refining heating time of 5 minutes was employed. The pH, buffering capacity, morphology, and the surface of the fibres were evaluated. The refined fibres were used to manufacture fibreboard panels at a target density of 720 kg/m3 and 12% urea formaldehyde (UF) resin. The panel's physical (thickness swelling) and mechanical properties (bending and internal bonding strength) were then evaluated according to European Standard (EN 622-5, 2006). The results indicated that refining conditions affected the properties of the fibres and final boards. High steam pressure and temperature-induced pH changes in OPF fibres, leading to more acidic fibres and greater acid buffering capacity. The fibre separation was more adequate at this level and produced fibre with a smooth surface. Based on the test results for fibreboard properties, high steam pressure and temperature produced better dimensional stability of panels and bending and bonding strength. However, at the highest refining condition (severe level), the board performances began to deteriorate. The best performances of the samples were found for the panels made under refining conditions of 6 bar at 170 °C.

scholarly journals Establishing Growing Substrate pH with Compost and Limestone and the Impact on pH Buffering Capacity

HortScience ◽  
2016 ◽  
Vol 51 (9) ◽  
pp. 1153-1158 ◽  
Author(s):  
Matthew D. Taylor ◽  
Rachel Kreis ◽  
Lidia Rejtö
Keyword(s):  
Factorial Design ◽  
Weight Ratio ◽  
Green Plant ◽  
Buffering Capacity ◽  
Ph Buffering ◽  
Initial Substrate ◽  
Initial Ph ◽  
The Impact ◽  
Substrate Ph ◽  
Ph Buffering Capacity

The pH of peatmoss generally ranges from 3.0 to 4.0 and limestone is typically added to raise pH to a suitable range. Compost is also used as a substrate component and typically has a high pH of 6.0 to 8.0. When using compost, lime rates must be reduced or eliminated. The two objectives of this study were to determine the resulting pH of substrates created with varying amounts of limestone and compost and assess the impact of the various amounts of limestone and compost on pH buffering capacity. Compost was created from a 1:1:1 weight ratio of a mixture of green plant material and restaurant food waste:horse manure:wood chips. The first experiment was a factorial design with five compost rates (0%, 10%, 20%, 30%, and 40% by volume), four limestone rates (0, 1.2, 2.4, and 3.6 g·L−1 substrate) with five replications. The experiment was conducted three times, each with a different batch of compost. With 0 lime, initial substrate pH increased from 4.5 to 6.7 as compost rate increased. This trend occurred at all other lime rates, which had pH ranges of 5.2–6.9, 5.6–7.0, and 6.1–7.1 for rates of 1.2, 2.4, and 3.6 g·L−1 substrate, respectively. Substrate pH increased significantly as either compost or lime rates increased. The second experiment was a factorial design with four compost rates by volume (0%, 10%, 20%, and 30%), the same four limestone rates as Expt. 1, and five replications. Each substrate treatment was titrated through incubations with six sulfuric acid rates (0, 0.1, 0.2, 0.4, or 0.7 mol of H+ per gram of dry substrate). Substrates with a similar initial pH had very similar buffering capacities regardless of the compost or limestone rate. These results indicate compost can be used to establish growing substrate pH similar to limestone, and this change will have little to no effect on pH buffering capacity.

Study of Methane Production by High Temperature Anaerobic Fermentation of Chicken Manure and Stalks

2020 ◽  
Vol 14 (4) ◽  
pp. 551-557
Author(s):  
Yongku Li ◽  
Xiaomin Hu ◽  
Lei Feng
Keyword(s):  
High Temperature ◽  
Anaerobic Digestion ◽  
Production Rate ◽  
Methane Production ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Gas Production ◽  
Chicken Manure ◽  
Biogas Slurry ◽  
Production Rates

The changing parameters, as the biogas production rate, the methane production rate, the cumulative biogas amount, the cumulative methane amount, the biogas composition, pH etc. in high temperature anaerobic fermentation of chicken manure and stalks were analyzed by experiments with different mass ratios of chicken manure or livestock manure and stalks with a high C/N ratio. The methane production mechanism of high temperature anaerobic digestion of chicken manure and stalks was discussed in detail. It showed that not only the biogas production rates but also the methane production rates of R1–R7 demonstrated the trend of initial increase and then decrease after 50 d of high temperature anaerobic digestion. Besides, the gas production of R1 with pure chicken manure stopped on the 30th d of the reaction. The gas production of other groups R2–R7 also stopped on the corresponding 34th, 36th, 36th, 37th, 37th, and 37th day, respectively. At the end of the reaction, the cumulative biogas amounts and the cumulative methane amounts of R1–R7 were 411.58 and 269.54, 459.91 and 314.41, 425.32 and 294.11, 401.85 and 272.54, 382.63 and 257.07, 363.04 and 218.16, and 257.15 and 160.10 N ml/(g VS). The biogas slurry pH of R1–R7 all demonstrated a trend of initial decrease and then increase, e. g., pH of R2 reached the minimum of 5.94 on the 5th day. pH values of other groups were between 6.01 and 6.39. After the addition of 4 g of sodium bicarbonate on the 7th day, biogas slurry pH of R1–R7 all increased. pH was maintained between 7.16 and 7.44 until the end of the reaction.

Exercise alters the regulation of myocardial Na+/H+ exchanger-1 activity

2013 ◽  
Vol 305 (10) ◽  
pp. R1182-R1189 ◽  
Author(s):  
Bryan J. Feger ◽  
Joseph W. Starnes
Keyword(s):  
Intracellular Ph ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Weight Ratio ◽  
Buffering Capacity ◽  
Strenuous Exercise ◽  
Sprague Dawley ◽  
Ph Buffering ◽  
Nhe1 Activity ◽  
Ph Buffering Capacity

The myocardial Na+/H+ exchanger-1 (NHE1) plays a major role in regulation of intracellular pH, and its upregulation has been implicated in increased ischemia-reperfusion injury and other pathologies. Hydrogen peroxide (H2O2) increases NHE1 activity acutely via ERK1/2 signaling. Chronic strenuous exercise upregulates NHE1 in skeletal muscle, but we hypothesize this will not occur in the heart, because exercise creates a cardioprotective phenotype. NHE1 activity and its regulation by H2O2 were examined at physiological pH using isolated cardiomyocytes from female Sprague-Dawley rats exercised on a treadmill for 5 wk (E; n = 11). Compared with sedentary (S; n = 15), E displayed increases ( P < 0.05) in heart-to-body weight ratio (6.8%) and plantaris mitochondria content (89%). NHE1 activity (acid efflux rate following an acid load) was 209% greater in E (0.65 ± 0.12 vs. 2.01 ± 0.29 fmol/min). The difference was attributed primarily to greater cell volume (22.2 ± 0.6 vs. 34.3 ± 1.1 pl) and intracellular pH-buffering capacity (33.94 ± 1.59 vs. 65.82 ± 5.20 mM/pH unit) of E myocytes. H2O2 stimulation (100 μM) raised NHE1 activity significantly less in E (45%) than S (167%); however, activity remained 185% greater in E. ERK1/2 inhibition abrogated the increases. H2O2-stimulated ERK1/2 phosphorylation levels normalized to total ERK1/2 were similar between groups. Content of NHE1 and activities of H2O2 scavengers were also similar. We observed that intracellular pH-buffering capacity differences between groups became progressively less with declining pH, which may be an exercise-induced cardioprotective adaptation to lower NHE1 activity during certain pathological situations. We conclude that strenuous endurance exercise increases myocardial NHE1 activity at physiological pH, which would likely enhance cardiac performance under physiological conditions.

Sign in / Sign up

Export Citation Format

Share Document