University of Manchester

Saline water evaporation from porous media

Salome Shokri
Project Completed

Scientific Case

Understanding of evaporation from porous media in the presence of dissolved salt is important in many natural and engineering processes, such as durability of building materials and preservation of pavements, paintings, and historical monuments, ecosystem functioning, mineral-fluid interactions, biodiversity in soil, crop production, soil salinity, and the problem of drinking water for the rapidly increasing population of the world. As water evaporates, the salt concentration in the pore space increases continually until it substantially exceeds the solubility limit (i.e., supersaturation exceeds a critical value) when it precipitates. Under certain conditions, salt deposition occurs preferentially at the surface of porous media. This is called efflorescence, and it refers specifically to evaporatively driven soluble salt from the interior of the porous media to the surface where evaporation occurs. In other cases, salt may deposit inside porous media called sub-florescence which can create extensive damage to materials under certain conditions. In any case, the precipitation pattern modifies the geometry and connectivity of the pore space and, consequently, influences various multiphase flow and transport processes in it. Also the presence of salt modifies the drying patterns and the evaporation rates from porous media. Yet, our physical understanding and ability to model the fate and transport of salt in drying porous media is still very limited, leaving many questions open. The key objectives of the present project are to develop quantitative tools and conduct a complete series of micro- and macro-scale experiments to evaluate the effects of various parameters such as pore size distribution and type of salt on the dynamics of salt transport and deposition patterns in porous media and its consequences on the evaporation rates.
Other
Soil physics

Experiment Design

It includes a cylindrical sand column (10 mm in diameter and 20 mm in height) saturated with NaCl solution (please see the proposal for more details).
Scanners and Rigs
Nikon Custom 320kV Bay
48
Not Required
2
I would like to use the High Flux Nikon XTEK bay in my experiments but could not find this in the list. So I chose CB320 instead.

Sample & Safety

Quartz sand and NaCl solution (please see the proposal for more detail)
2
Low Hazard

Scan Records

Project Report