Experimental analysis of saline diffusion during saltwater freezing for desalination purposes

The Freezing Melting (F/M) is considered one of the most sustainable desalination techniques in terms of energy consumption compared with commercial desalination. However, it presents some problems, especially salt trapping in the ice. In this paper, an experimental analysis is carried out to achieve a better understanding of saline ions displacement observed during the freezing of saline water. Different sizes, freezing temperatures and, geometries are tested using the F/M progressive desalination. It is found that salt diffusion improves with increasing the container length. Moreover, for all container geometries, the saline ion diffusion direction is from the bottom to the top of the formed ice. Furthermore, at low freezing temperature (−8°C), it is possible to purify 78.8 % of the frozen water, obtaining an easy-to-separate brine.