Abstract
Heat-transfer phenomena as well as moisture movement in unsaturated soils due to thermal gradients, have been extensively studied during the last four decades. Less attention has been devoted to the transport and redistribution of solutes caused by heating.
Solar radiation, radioactive waste repositories, underground energy storage, buried electric cables and steam pipes, disposal of waste heat from power plants are examples of heat sources in the soil.
Soil-water properties, such as surface tension, viscosity, density, as well as the equilibrium composition of phases, depend on temperature. Hence, nonuniform heating of a soil partially saturated by saline water has an effect on such processes as water flow under capillary and gravitational forces, evaporation, condensation and diffusion of vapor and transport and precipitation of salts.
A mathematical model is presented for the migration of salts in the vadoze zone in the soil under nonisothermal conditions, taking into account the above-mentioned phenomena. The physical assumptions underlying the model are briefly discussed.
The study of a particular case shows that under certain conditions, a heat source may attract dissolved salts, and cause their precipitation in the hot area.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abdel-Hadi, O. N., and Mitchell, J. K.: 1981, Coupled heat and water flows around buried cables,Geotechn Div. 107, 1461–1487 (Nov.).
Bear, J. and Bachmat, Y.: 1990,Introduction to Modelling of Transport Phenomena in Porous Media, Kluwer Academic, Dordrecht.
Bear, J. and Bensabat, J.: 1989, Advective fluxes in multiphase porous media under nonisothermal conditions,Transport in Porous Media,4, 423–448.
Bear, J., Bensabat, J. and Nir, A.: 1991, Heat and mass transfer in unsaturated porous media at a hot boundary, I. One-dimensional analytical model,Transport in Porous Media 6, 281–298.
Bear, J. and Nitao, J.: 1993, Infiltration and contaminant transport in the vadose zone (nonisothermal), part 1: Conceptual and mathematical models, Technical report UCRL-JC-111742 Pt.1, Lawrence Livermore National Library.
Bear, J. and Nitao, J.: 1993, On equilibrium and primary variables in transport in porous media, Technical Report UCRL-JC-11743 Pt.1, Lawrence Livermore National Laboratory.
Bensabat, J.: 1986, Heat and Transfer in Unsaturated Porous Media with Application to an Energy Storage Problem, PhD thesis, Technion, Israel (in Hebrew).
Bird, R. B., Stewart, W. E. and Lightfoot, E. N.: 1960,Transport Phenomena, Wiley, New York.
Cass, A., Campbell, G. S. and Jones, T. L.: 1984, Enhancement of thermal water vapor diffusion in soil,Soil Sci. Soc. Am. J. 48 (1), 25–32 (Jan.).
Childs, S. W. and Malstaff, C.: 1982, Heat and mass transfer in unsaturated porous media, Technical report, Battelle Pacific Northwest Laboratories.
Doughty, C., Korin, E., Nir, A. and Tsang, C.-F: 1990, Seasonal storage of thermal energy in unsaturated soils: Modelling, simulation and field validation,STES Newsletter,12 (1–2).
Gray, D. (ed): 1963,American Institute of Physics Handbook, McGraw-Hill, New York.
Groenevelt, P. H. and Bolt, G. H.: 1969, Non-equilibrium thermodynamics of the soil-water system,Hydrology 7 358–388.
Hassanizadeh, S. M.: 1986, Derivation of basic equations of mass transport in porous media, Part 2, Generalized Darcy's and Fick's laws,Adv. Water Resour. 9, 207–222 (Dec.).
Jury, W. A. and Letey, J.: 1979, Water vapor movement in soil: Reconcillation of theory and experiment,Soil Sci. Soc. Am. J. 43 (5), 823–827 (Sept.).
Norbe, R. C. M. and Thomson, N. R.: 1993, The effects of transient temperature gradients on soil moisture dynamics,Hydrology 152 (1–4), 57–101 (Dec.).
Philip, J. R. and Vries, D. A. D.: 1993, Moisture movement in porous materials under temperature gradients,Trans. Amer. Geophys. Union 38 (2), 222–232.
Vargaftik, N. B.: 1975,Tables of the Thermophysical Properties of Liquids and Gases, Wiley, New York.
Vries, D. A. D.: 1963, Thermal properties of soils, in Van Wijk, W. R., (ed),Physics of the Plant Environment, North-Holland Publishing Co., Amsterdam.
Weast, R. C. and Astle, M. J. (eds): 1981–1982,CRC Handbook of Chemistry and Physics, 62nd edn., CRC Press.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bear, J., Gilman, A. Migration of salts in the unsaturated zone caused by heating. Transp Porous Med 19, 139–156 (1995). https://doi.org/10.1007/BF00626663
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00626663