Unusual properties of water: Effects on desalination processes

Abstract

Recent research on the fundamental properties of liquid water has been applied to demonstrate potential new improvements to the three main technologies for desalination. They have demonstrated that the so-called 'inert' atmospheric gases, oxygen and nitrogen, have a significant influence, even at their relatively low level of solubility. For example, the almost complete removal of these dissolved gases enhances the dispersion of fine oil droplets in water, simply by shaking, without the need for added surfactants. Even more importantly, the almost complete degassing of liquid water significantly enhances its natural electrical conductivity. These discoveries have recently been applied to the development of ideas for the improvement of reverse osmosis and electrodialysis. In addition, investigations of the effect of salt on the dispersion of bubbles in water have allowed the construction of a high density air bubble column to transfer water vapour under controlled sub-boiling conditions