scholarly journals Methane Oxidation Efficiency in Biofiltration Systems with Different Moisture Content Treating Diluted Landfill Gas

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2872
Author(s):  
Niccolò Frasi ◽  
Elena Rossi ◽  
Isabella Pecorini ◽  
Renato Iannelli
Keyword(s):  
Moisture Content ◽  
Methane Oxidation ◽  
Landfill Gas ◽  
Bacterial Activity ◽  
Column Tests ◽  
Moisture Contents ◽  
Optimal Value ◽  
Ch4 Concentration ◽  
Set Up ◽  
Oxidation Efficiency

This study investigates the influence of moisture content on the potential oxidation efficiency of methane (CH4) of biofiltration systems treating landfill gas containing high oxygen concentrations. Column tests filled with compost with different moisture contents (20%, 30%, and 40%) loaded with different methane flows were set up on a laboratory scale. Analyzing the results the following evidences can be summarized: With low methane load (<100 g CH4 m−2 d−1), a moisture content of 20% was not enough to support bacterial activity, while a moisture content of 40% advantaged the compost respiration assisting it to become the dominating process; with higher methane load (100–300 g CH4 m−2 d−1), a moisture content of 30% resulted in an optimal value to support methanotrophic activity showing the highest CH4 concentration reduction; moving on to a CH4 load above 300 g CH4 m−2 d−1, the inhibition of methanotrophic activity emerged independently to the moisture content of the filter media. The optimal configuration is obtained for a moisture content of 30% and in the case of flows below 200 g CH4 m−2 d−1 for which the oxidation efficiency results higher than 80%.

scholarly journals Comparative study of methane oxidation within various biofilter media

2021 ◽  
Author(s):  
Sepideh Nourbakhsh
Keyword(s):  
Methane Oxidation ◽  
Landfill Gas ◽  
Oxygen Demand ◽  
Bacterial Development ◽  
Methane Gas ◽  
Sand Control ◽  
Oxidation Efficiency ◽  
Methane Utilization ◽  
Bod Removal ◽  
Over Time

A considerable fraction of the methane gas generated by landfills can be oxidized by the landfill cover. In this study, the use of disposable sawdust material to utilize and reduce methane gas from the landfill gas (LFG) was demonstrated. Three laboratory scale bioreactors were constructed to reflect the performance of sawdust with respect to the compost and sand (control media). Patterns of methane (CH₄) oxidation were evaluated through the degree of methane oxidation in correlation to the bacterial development in all three media. Later, the use of nutrients during the respiration of the bacteria was interpreted through the analysis of chemical oxygen demand (COD), biochemical oxygen demand (BOD), and biomass growth variations. The overall methane oxidation efficiency in the sawdust medium was 60% with a biomass content of 238 g/m³, whereas the compost medium had 86% methane oxidation efficiency with a 539 g/m³ biomass content. Furthermore, the COS and BOD removal were 2555 mg/L and 332 mg/L from the compost, and 1984 mg/L and 156 mg/L from the sawdust respectively. The overall results of this study indicated that the sawdust material can be used as a biofilter media for methane utilization from the landfill. The oxidation capacity of sawdust could be accelerated by adding necessary nutrients to this media before implementation. Moreover, the oxidation rate variance between compost and sawdust may be eliminated over time due to nutrient exhaustion in the compost media, and/or production of usable carbon with decomposition of the sawdust media.

scholarly journals Comparative study of methane oxidation within various biofilter media

2021 ◽  
Author(s):  
Sepideh Nourbakhsh
Keyword(s):  
Methane Oxidation ◽  
Landfill Gas ◽  
Oxygen Demand ◽  
Bacterial Development ◽  
Methane Gas ◽  
Sand Control ◽  
Oxidation Efficiency ◽  
Methane Utilization ◽  
Bod Removal ◽  
Over Time

A considerable fraction of the methane gas generated by landfills can be oxidized by the landfill cover. In this study, the use of disposable sawdust material to utilize and reduce methane gas from the landfill gas (LFG) was demonstrated. Three laboratory scale bioreactors were constructed to reflect the performance of sawdust with respect to the compost and sand (control media). Patterns of methane (CH₄) oxidation were evaluated through the degree of methane oxidation in correlation to the bacterial development in all three media. Later, the use of nutrients during the respiration of the bacteria was interpreted through the analysis of chemical oxygen demand (COD), biochemical oxygen demand (BOD), and biomass growth variations. The overall methane oxidation efficiency in the sawdust medium was 60% with a biomass content of 238 g/m³, whereas the compost medium had 86% methane oxidation efficiency with a 539 g/m³ biomass content. Furthermore, the COS and BOD removal were 2555 mg/L and 332 mg/L from the compost, and 1984 mg/L and 156 mg/L from the sawdust respectively. The overall results of this study indicated that the sawdust material can be used as a biofilter media for methane utilization from the landfill. The oxidation capacity of sawdust could be accelerated by adding necessary nutrients to this media before implementation. Moreover, the oxidation rate variance between compost and sawdust may be eliminated over time due to nutrient exhaustion in the compost media, and/or production of usable carbon with decomposition of the sawdust media.

scholarly journals Qualidade sanitária de grãos de soja avariados por percevejo na lavoura e armazenados em diferentes condições

2021 ◽  
Vol 1 (54) ◽  
pp. 148
Author(s):  
Jaqueline Ferreira Vieira Bessa ◽  
Osvaldo Resende ◽  
Rayr Rodrigues Lima ◽  
Maria Aparecida Da Silva Lopes ◽  
Carolina De Freitas Fófano Garcia ◽  
...  
Keyword(s):  
Moisture Content ◽  
Water Activity ◽  
Storage Temperature ◽  
Effect Of Temperature ◽  
Stink Bug ◽  
Moisture Contents ◽  
Randomized Design ◽  
Set Up ◽  
Storage Temperatures

<p><span class="fontstyle0">The objective of this work was to evaluate, throughout the storage, the effect of temperature and moisture content on soybean grains with high damage caused by stink bug in the crop, through sanitary quality. Two moisture contents (11.75 and 13.84% wet base) were used and the grains were packed in high density polyethylene packages (HDPE), stored in four BOD’s, regulated at temperatures of 20, 25, 30 and 35 °C and evaluated every two months by analyzing the water activity, grain sanity and the occurrence index. The experiment was set up in a completely randomized design and in a 2 x 4 x 4 factorial scheme, with two moisture contents, four storage temperatures and four evaluation times. The moisture content and the temperatures throughout the storage influence the sanitary quality of the soybean grains damaged by stink bug. The higher the moisture content and the storage temperature, the higher the water activity of soybeans damaged by bedbug, and the increase in the occurrence of fungi</span> <br /><br /></p>

The Smoulder Stream of Cigarettes / Zur Kenntnis des Glimmstromes von Cigaretten

1965 ◽  
Vol 3 (2) ◽  
Author(s):  
F. Seehofer ◽  
W. Schulz
Keyword(s):  
Moisture Content ◽  
Spatial Position ◽  
High Yield ◽  
Physical Conditions ◽  
Moisture Contents ◽  
Cigarette Paper ◽  
First Time

AbstractThe phenomenon of the smoulder stream flowing through the cigarette during smouldering and during the puff intervals is demonstrated for the first time and its dependence upon physical conditions is examined. The volume of the smoulder stream can amount up to 180 ml per cigarette. Increasing draw resistance of the cigarette and augmenting moisture content of the tobacco as well as perforation of the cigarette paper have a decreasing effect on volume and velocity of the smoulder stream. The porosity of the cigarette paper has no perceptible influence. The spatial position of the cigarette affects volume and velocity of the smoulder stream. The influence exercised by the smoulder stream on the yields of total condensate, nicotine, phenols, aldehydes, and acroleine when the cigarette tip is open during the puff intervals is determined. When the moisture contents of the tobacco were extremely high, yield decreases reaching 50 % could be observed.

Developing a Linearization Method to Determine Optimum Blending for Surimi with Varied Moisture Contents Using Linear Programming

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Hyeon W. Park ◽  
Jae W. Park ◽  
Won B. Yoon
Keyword(s):  
Linear Programming ◽  
Moisture Content ◽  
Standard Procedure ◽  
Unit Cost ◽  
Linearization Method ◽  
Model Parameters ◽  
Additional Information ◽  
Moisture Contents ◽  
Design Variables ◽  
Critical Moisture

AbstractNovel algorithm to determine the least cost formulation of a surimi blend was developed using linear programming (LP). Texture properties and the unit cost of surimi blend at the target moisture content were used as constraint functions and the objective function, respectively. The mathematical models to describe the moisture content dependence of the ring tensile properties were developed using critical moisture content, and the model parameters were used for the least cost LP (LCLP) model. The LCLP model successfully predicted the quality of surimi blend. Sensitivity analysis was used to obtain an additional information when the perturbations of design variables are provided. A standard procedure to determine the least cost formulation for blending surimi with varied moisture contents was systematically developed.

scholarly journals Experimental Study on the Softening Characteristics of Sandstone and Mudstone in Relation to Moisture Content

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Gui-chen Li ◽  
Chong-chong Qi ◽  
Yuan-tian Sun ◽  
Xiao-lin Tang ◽  
Bao-quan Hou
Keyword(s):  
Moisture Content ◽  
Vertical Displacement ◽  
Surface Porosity ◽  
Shear Tests ◽  
Moisture Contents ◽  
Dynamic Finite Element ◽  
Rock Types ◽  
Underground Roadway ◽  
The Stability ◽  
Kinetics Of

The kinetics of fluid-solid coupling during immersion is an important topic of investigation in rock engineering. Two rock types, sandstone and mudstone, are selected in this work to study the correlation between the softening characteristics of the rocks and moisture content. This is achieved through detailed studies using scanning electron microscopy, shear tests, and evaluation of rock index properties during exposure to different moisture contents. An underground roadway excavation is simulated by dynamic finite element modeling to analyze the effect of moisture content on the stability of the roadway. The results show that moisture content has a significant effect on shear properties reduction of both sandstone and mudstone, which must thus be considered in mining or excavation processes. Specifically, it is found that the number, area, and diameter of micropores, as well as surface porosity, increase with increasing moisture content. Additionally, stress concentration is negatively correlated with moisture content, while the influenced area and vertical displacement are positively correlated with moisture content. These findings may provide useful input for the design of underground roadways.

Effect of Bromus inermis Leyss Planting on Dynamic Changes of Soil Moisture Contents on the Bare Slope

2013 ◽  
Vol 807-809 ◽  
pp. 1648-1652
Author(s):  
Tie Jun Sun ◽  
Baderihu Tajilake
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Regulatory Mechanism ◽  
Dynamic Balance ◽  
Bromus Inermis ◽  
Dynamic Changes ◽  
Moisture Contents ◽  
Biological Characters ◽  
Underground Biomass

Experiment was executed to plant eco-grass of Bromus inermis Leyss on 15°bare slopes, and study effect of biological characters on dynamics of soil moisture contents. The results indicated that vegetation restored quickly on the bare slope after the eco-grass planted. There were 2473.4 kg/hm2 of overground biomass and 1744.1kg/hm2 of underground biomass, and 70% of underground biomass was in 0-10cm layer of soil. Meanwhile, there was a regulatory mechanism of soil moisture content for Bromus inermis Leyss. When rainfall was enough, soil moisture content in 0-80 cm layer could reach to the most of 26.83% quickly this year. Next it could decline near to the first value of 19.81% after rainfall stopped, and keep a dynamic balance between 19.48% and 19.96%. Moreover, the regulatory mechanism realized though underground biomass, and was clearer with underground biomass increasing, especially in the 0-40cm layer of soil.

Assessment of Moisture Content in Sandy Beach Environments from Multispectral Satellite Imagery

2021 ◽  
Author(s):  
Julie Paprocki ◽  
Nina Stark ◽  
Hans C Graber ◽  
Heidi Wadman ◽  
Jesse E McNinch
Keyword(s):  
Moisture Content ◽  
Laboratory Data ◽  
Field Measurements ◽  
Weather Conditions ◽  
Sandy Beaches ◽  
Percent Error ◽  
Moisture Contents ◽  
Multispectral Satellite Imagery ◽  
Factor C

A framework for estimating moisture content from satellite-based multispectral imagery of sandy beaches was tested under various site conditions and sensors. It utilizes the reflectance of dry soil and an empirical factor c relating reflectance and moisture content for specific sediment. Here, c was derived two ways: first, from in-situ measurements of moisture content and average NIR image reflectance; and second, from laboratory-based measurements of moisture content and spectrometer reflectance. The proposed method was tested at four sandy beaches: Duck, North Carolina, and Cannon Beach, Ocean Cape, and Point Carrew, Yakutat, Alaska. Both measured and estimated moisture content profiles were impacted by site geomorphology. For profiles with uniform slopes, moisture contents ranged from 3.0%-8.0% (Zone 1) and from 8.0%-23.0% (Zone 2). Compared to field measurements, the moisture contents estimated using c calibrated from in-situ and laboratory data resulted in percent error of 3.6%-44.7% and 2.7%-58.6%, respectively. The highest percent error occurred at the transition from Zone 1 to Zone 2. Generally, moisture contents were overestimated in Zone 1 and underestimated in Zone 2, but followed the expected trends based on field measurements. When estimated moisture contents in Zone 1 exceeded 10%, surface roughness, debris, geomorphology, and weather conditions were considered.

Propagation velocity model of stress waves in larch wood (Larix gmelinii) three-dimensional space with different moisture contents

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6680-6695
Author(s):  
Xiwen Wei ◽  
Liping Sun ◽  
Hongjv Zhou ◽  
Yang Yang ◽  
Yifan Wang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Wave Velocity ◽  
Stress Wave ◽  
Propagation Velocity ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Stress Waves ◽  
Moisture Contents ◽  
Direction Angle ◽  
Stress Wave Velocity

Based on the effects of stress wave propagation in larch (Larix gmelinii) wood, the propagation mechanism of stress wave was explored, and a theoretical model of the propagation velocity of stress waves in the three-dimensional space of wood was developed. The cross and longitudinal propagation velocities of stress wave were measured in larch wood under different moisture contents (46% to 87%, 56% to 96%, 20% to 62%, and 11% to 30%) in a laboratory setting. The relationships between the propagation velocity of stress waves and the direction angle or chord angle with different moisture contents were analyzed, and the three-dimensional regression models among four parameters were established. The analysis results indicated that under the same moisture content, stress wave velocity increased as the direction angle increased and decreased as chord angle increased, and the radial velocity was the largest. Under different moisture contents, stress wave velocity gradually decreased as moisture content increased, and the stress wave velocity was more noticeably affected by moisture content when moisture content was below the fiber saturation point (FSP, 30%). The nonlinear regression models of the direction angle, chord angle, moisture content, and the propagation velocity of stress wave fit the experiment data well (R2 ≥ 0.97).

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