Desalination by freezing/thawing method was a very important method to obtain fresh water from sea water. In this work

desalination by freezing/thawing method was conducted with initial sodium chloride of 3.5 wt% in consideration of stirring speed

freezing time and subcooling. The subcooling ranged from 1.2 K to 4 K. The optimum conditions for desalination in this work were stirring speed of 200 r·min

-1

freezing time of 120 min

and subcooling of 3 K. The results also showed that sodium chloride cannot be effectively removed by once freezing/thawing process. The maximum removal efficiency of sodium chloride was 64.3%. Two major reasons resulting in the impurity of obtained melted water by freezing/thawing method were proposed. The first reason was the inevitable adhesion of salt solution to the surface of ice

which could be removed easily by distilled water flushing. The second reason was that salt solution was heterogeneously wrapped in the accumulated ice

which was difficult to be removed by distilled water flushing. The liquid flushing method was proposed to verify the conjecture

and the results were in accordance with the two reasons mentioned above. Additional method

such as mul

tiple flushing liquid method

was suggested to be used during the freezing/thawing process for effectively removing sodium chloride

and obtaining fresh water.