Getting a Fix on Freeze Concentration

Freeze concentration is an overlooked technology for separating pure water from various mixtures including milk, fruit juices, vinegar, wine, and wastewater. Some people have inadvertently experienced the process when liquids freeze in an over-chilled refrigerator or while held outside in the winter.

When the temperature of an aqueous solution is reduced below the freezing point of water (32°F or 0°C), pure ice crystals form, leaving behind the dissolved solids. The process is mass transfer contr…