Laboratory freezing desalination of seawater

Freeze desalination of samples of seawater from Umluj beach, Red Sea, in Saudi Arabia, was investigated by laboratory experiments using nondirect freezing. The influence of kinetic parameters including degree of crystallization, freezing–melting cycles, and gradual melting on the total dissolved solids (TDS) and salt rejection was examined. The melted ice water produced by partial crystallization of single-stage freezing has two times less salt concentration than the feed seawater (TDS, 40,916 mg/l). Continuous cycling of the freezing–melting process reduced the dissolved salts to 1.5% with TDS 610 mg/l, in the level of drinking water. The TDS of the melted ice decreased with gradual melting time and reached 693 mg/l after 6 h. The results indicated that the laboratory freezing desalination could decrease sea ice salinity from 4.1 to 0.06% without using chemical additives.