Water Vapor Adsorption and Soil Wetting

Abstract

Soil water management and irrigation practices largely depend on a timely and accurate characterization of temporal and spatial soil moisture dynamics in the root zone. Consequently, measurements and detailed information about soil water sorption, water content, behavior, and potential are required. In that concern, water vapor adsorption is an important phenomenon in arid and semi-arid regions, as well as in dry periods of tropical soils. Therefore, quantifying adsorption is important for agricultural water management, surface energy balance studies, ecological studies, and remote sensing investigations changes in surface soil moisture content will affect land surface properties such as albedo, emissivity, and thermal inertia . The vapor pressure and isothermal adsorption of water vapor can be used to predict soil moisture adsorption capacity Wa , specific surface area, and hydro-physical properties of arid soils such as in Egypt and in the tropical soils in Ecuador. Theory of adsorption of water vapor on soil particles is developed among the mono-molecular and poly-molecular adsorption with respect to "runauer, Emmett, and Teller "ET theory. Data of soil-water adsorption W% at different relative vapor pressures P/Po can be obtained for the soils, where the W% values are increased with increasing P/Po in general. The highest values of water adsorption capacity Wa , specific surface area S , and other hygrophysical properties such as adsorbed layers and maximum hygroscopic water are observed in the clay depths of soil profiles, while the lowest values can be found in coarse textured soils sandy and sandy loam soils profiles . Two equations were assumed to predict P/Po at water adsorption capacity Wa and to applyWa in prediction of soil moisture retention, i.e., ψ W function at pF < . .

Soil moisture adsorption capacity and specific surface area in relation to water vapor pressure in arid and tropical soils

“…This result may refer to the mineralogical composition of these soils (Figure 2), whereas the montmorillonite, ferrous and hydrous mica are the prevailing minerals in the tropical soils as well as in the clay alluvial arid soils of the Nile Delta (El-Gabaly and Khadr, 1962). (Amer, 2015).…”

“…. Clay soil samples were taken at depth ˃90 cm from INIAP research station-Pichilingue, Ecuador ~containing ferrous and ferric minerals with the highest values of surface area and water adsorption capacity (Amer, 2015).…”

“…At high relative water vapor pressures, the amount Ce / (Ce + Po/P -Ke) is equal unit (Farrar, 1963), and then the equation ( 6) becomes (Amer, 2015):…”

Boundary conditions for the problem of moisture transport in concrete

“…However, the process of moisture transport is not stop -under the relative humidity gradient influence, water to be evaporate from the concrete and condense in the soil capillaries, increasing its degree saturation until equilibrium is reached. The soil environment relative humidity RH can be determined by the following equation of Kelvin capillary condensation [21][22][23]…”

To the question of concrete creep in the soil environment

“…В гидрометеорологии, почвоведении и теории переноса вещества в пористых средах общепринято [18][19][20][21][22][23][24][25] • давление воды в почве P в , Па, получаемое путем умножения Ψ w на плотность воды;…”