Novel Applications of Non Hofmeister Ion Specificity in Bubble Interactions

•A range of ion effects form the basis for some BCE applications.•The effects of many salts on inhibiting bubbles coalescence lift BCE applications.•Low levels of divalent ions could significantly improve BCE sterilization.•The BCE improvement by Ca2 + is due to changing surface charge on cells and bubbles.•Lower levels of multivalent salts or polymers might widen the BCE sterilization.

The ion specificity of bubble-bubble interactions in water remains unexplained. Whatever their valence all ion pairs either completely inhibit bubble coalescence or have no effect whatever. The phenomenon appears unrelated to Hofmeister specificity. Salts which inhibit coalescence enable the formation of a high density bubble column evaporator (BCE). If hot gas bubbles are injected into the bubble column evaporator at a significantly higher temperature than the water, the hot bubble surfaces can be used to produce thermal effects in dissolved and dispersed solutes. These two properties can be exploited for a wide range of applications. Among these, high temperature aqueous reactions catalyzed at low solution temperatures, measurement of enthalpies of vaporization of concentrated salt solutions, wastewater treatments by sterilization and de-watering and desalination are a few.

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