Extracting emulsions for the extraction of substances from aqueous media

The characteristic features of the extracting emulsions used to extract and concentrate substances from aqueous solutions are examined. The influence on the properties of the extracting emulsions of the conditions in their preparation, of the properties of the disperse phase (the ionic strength and the pH of the aqueous solutions), the properties of the dispersion medium (viscosity, dielectric constants), as well as the presence of polar organic substances in the emulsions is discussed. The influence of the nano-dispersion formed on mass transfer through the interface and on the properties of the extracting emulsions is demonstrated. The approaches to the mathematical description of the kinetics of the processes in extracting emulsions are discussed and it is shown that extracting emulsions with various properties designed for a wide variety of applications can be developed on the basis of the study of the physicochemical properties of such disperse systems. Examples of the use of extracting emulsions in chemical engineering for the extraction of substances from aqueous media by membrane extraction into a multicomponent emulsion, for preliminary concentration in analysis, for therapeutic and prophylactic purposes in medicine, and for the protection of the environment are considered. The bibliography includes 102 references.