Green and sustainable separation of metal ions and synthetic dyes from aqueous solutions using deep eutectic solvents. A mini review

Abstract

The development of eco-friendly methods for removing hazardous inorganic and organic contaminants (e.g., metal ions, synthetic dyes) from water systems is of great importance for the health and life of humans and animals. Recently, there has been growing interest in the possibilities of using deep eutectic solvents (DESs) in separation processes aimed at removing various pollutants from aqueous solutions. DESs are typically non-toxic, biodegradable, and can be synthesised using simple methods. Moreover, the components used in DES synthesis, often considered “green” solvents, can be derived from natural sources. DESs are generally recyclable and relatively cheap. This review highlights recent advancements (mainly from 2023–2024) in the application of various DESs for the removal of metal and metalloid ions, as well as synthetic dyes, from aqueous solutions using solvent extraction (SE) and membrane separation (MP). It also includes critical comments on the limitations of current methods and their potential environmental impacts.