scholarly journals Relationship between specific surface area and the dry end of the water retention curve for soils with varying clay and organic carbon contents

2011 ◽  
Vol 47 (6) ◽  
Author(s):  
Augustus C. Resurreccion ◽  
Per Moldrup ◽  
Markus Tuller ◽  
T. P. A. Ferré ◽  
Ken Kawamoto ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Water Retention ◽  
Water Retention Curve ◽  
Retention Curve

Modelling the saturated hydraulic conductivity of soils amended with different biochars

2020 ◽  
Author(s):  
Boguslaw Usowicz ◽  
Jerzy Lipiec
Keyword(s):  
Hydraulic Conductivity ◽  
Organic Carbon ◽  
Statistical Model ◽  
Water Retention ◽  
Saturated Hydraulic Conductivity ◽  
Carbon Accumulation ◽  
Water Retention Curve ◽  
Satellite Monitoring ◽  
Model Parameters ◽  
Retention Curve

<p>Soil organic carbon accumulation is central to the improvement of many soil properties and functions. Biochar use and management could be particularly beneficial for soils with low organic carbon content. It's known that many of soils in the world intrinsically exhibit little ability to retain water and nutrients due to their texture and mineralogy. Also, acquiring biomass for other than agricultural purposes can reduce the organic carbon accumulation and worsens the soil quality. Adding biochar to the soil can affect saturated hydraulic conductivity, water holding capacity and reduce soil erosion and mineral fertilization. It has been shown that saturated hydraulic conductivity depends on type of feedstock and pyrolysis temperatures used for biochar production and application dose but the results are inconsistent. Therefore, in order to explain the different biochar impacts, we propose in this study the use the physical-statistical model of B. Usowicz for predicting the saturated hydraulic conductivity using literature data for various soils amended with biochars (from woodchip, rice straw and dairy manure), pyrolyzed at 300, 500 and 700 °C.  </p><p>Soil with biochar and pores between them can be represented by a pattern (net) of more or less cylindrically interconnected channels with different capillary radius. When we view a porous medium as a net of interconnected capillaries, we can apply a statistical approach for the description of the liquid or gas flow. The soil and biochar phases and their configuration is decisive for pore distribution and the course of the water retention curve in this medium. The physical-statistical model considers the pore space as the capillary net that is represented by parallel and serial connections of hydraulic resistors in the layer and between the layers, respectively. The polynomial distribution was used in this model to determine probability of the occurrence of a given capillary configuration. Capillary size radii and the probability of occurrence of a given capillary configuration were calculated based on the measured water retention curve and saturated water content. It was found a good agreement between measured and the model-predicted hydraulic conductivity data for the biochar amended soils. It indicates that the used variables and model parameters to predict the saturated hydraulic conductivities of the soils were chosen correctly. The different types and pyrolysis temperatures of biochars affected the soil water retention and the equivalent length of the capillaries that characterize the pore tortuosity in the soil.</p><p> </p><p>Acknowledgements. Research was conducted under the project “Water in soil - satellite monitoring and improving the retention using biochar” no. BIOSTRATEG3/345940/7/NCBR/2017 which was financed by Polish National Centre for Research and Development in the framework of “Environment, agriculture and forestry” - BIOSTRATEG strategic R&D programme.</p>

Binding of water-extractable organic carbon to clay subsoil: effects of clay subsoil properties

Soil Research ◽  
2015 ◽  
Vol 53 (1) ◽  
pp. 81 ◽  
Author(s):  
Shinhuey Lim ◽  
Trung-Ta Nguyen ◽  
Petra Marschner
Keyword(s):  
Organic Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sandy Soils ◽  
Clay Content ◽  
Sodium Absorption ◽  
Oxide Content ◽  
Relative Importance ◽  
Water Extractable

Addition of clay-rich subsoils to sandy soils can increase yield and may increase organic carbon (OC) retention in soils. The ability of clays to bind OC is likely to be influenced by clay properties, but little is known about the relative importance of properties of clay subsoils for binding of OC. A batch sorption experiment was conducted using seven clay subsoils collected from agricultural lands where claying was carried out. Clay subsoils were shaken for 17 h at 4°C with different concentrations of water-extractable OC (WEOC: 0, 2.5, 5.0, 7.5, and 9.0 g kg–1 soil) derived from mature wheat (Triticum aestivum L.) straw at a 1 : 10 soil : extract ratio. Sorption of WEOC was positively correlated with clay content, specific surface area and concentration of iron oxides. Further, WEOC sorption was negatively correlated with total OC content, sodium absorption ratio and cation ratio of soil structural stability. However, the relative importance of these properties for WEOC sorption differed among soils. In conclusion, OC retention in clay-amended sandy soils will be positively related to clay soil properties such as clay and Fe oxide content and specific surface area.

scholarly journals Determination of soil specific surface area by water vapor adsorption: II Dependence of soil specific surface area on clay and organic carbon content

1987 ◽  
Vol 59 (2) ◽  
pp. 67-72
Author(s):  
Raina Niskanen ◽  
Väinö Mäntylahti
Keyword(s):  
Water Vapor ◽  
Organic Carbon ◽  
Specific Surface ◽  
Carbon Content ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mineral Soil ◽  
Water Vapor Adsorption ◽  
Organic Carbon Content ◽  
Vapor Adsorption

The specific surface area of 60 mineral soil samples estimated by water vapor adsorption at 20 % relative humidity ranged from 12.1 ± 3.6 to 225.1 ±18.4 m2/g. Clay (range 1—72 %) and organic carbon content (0.7—14.6 %) together explained 84 % of the variation in the surface area. The regression equation predicting the specific surface area of soil was surface area (m2/g) =2.69+ 1.23clay-% +8.69org.C-%.

The Influence of Milling Parameters on the Fibrillation of PBO Fiber

2012 ◽  
Vol 482-484 ◽  
pp. 1894-1897 ◽  
Author(s):  
Lin Liu ◽  
Guang Li
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rotation Number ◽  
Water Retention ◽  
Processing Parameters ◽  
High Specific Surface Area ◽  
Water Retention Value ◽  
Milling Parameters ◽  
Pbo Fiber

PFI mill was used to prepare PBO fibrils from PBO fiber. With the help of the observation of SEM and the measure of water retention value as well as the analysis of specific surface area, it was found that the milling parameters, including the beating rotation number, beating spacing, beating pressure and beating concentration, influenced the fibrillation of PBO fiber. The processing parameters were studied. The optimal milling conditions were obtained: beating rotation number of 40000-50000r, spacing of 2.4mm, pressure of 4.89N/mm, and concentration of 7.5%. The prepared PBO fibrillar fiber has high specific surface area of 5.001m2/g, while the original PBO fiber has only a specific surface area of 0.476m2/g.

Modification of Cellulase to Different Bleached Softwood Pulp

2012 ◽  
Vol 550-553 ◽  
pp. 1186-1189
Author(s):  
Min Du ◽  
Xin Ping Li ◽  
Jin Wang ◽  
Peng Zhou Wang
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Water Retention ◽  
Raw Material ◽  
Enzymatic Modification ◽  
Water Retention Value ◽  
Wetting Properties ◽  
Before And After ◽  
Wetting Property

Cellulase named as Novozym 476 was used to modify three kinds of bleached softwood pulps respectively. By analyzing the changes of refining degree, water retention value, specific surface area, wetting properties of fiber before and after enzymatic treatment, studied the influence of characteristics of raw material to the effect of enzymatic modification. The results indicate that in the same conditions, the refining property, water retention value, specific surface area and wetting property of the three pulps all increase. Among these three pulps, the pulp of Kamloops Kraft has the best modification effect. Refining degree of Kamloops Kraft pulp increases 36.0 °SR when refining for 10,000 PFI revolutions, and the water retention value increases by 68.0%, the dye loading increases with 0.1 mg/g, the contact angle decreases by 4.5%. It illustrates that the fiber raw material with a thin cell wall would have a better effect of enzymatic modification and the wrapping way of microfibers would influence the effect of enzymatic modification.

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