Selective Recovery of Critical and Toxic Elements from Their Low-Concentrated Solutions Using Surface-Based Electrochemical Separation Methods

Economic and eco-friendly recovery of elements from their low-concentrated solutions in complex aqueous matrices is recognized as one of the greatest challenges of industrial inorganic separation. In the quest to develop such a technology, significant progress has been achieved by surface-based electrochemical separation methods. This progress has principally been underpinned by hybridizing conventional surface-based electrochemical separation methods such as electrosorption, chemisorption, intercalation, electrodeposition, and electroprecipitation with each other, as well as with membrane methods. This methodological upgrade has demonstrated potential to overcome intrinsic limitations while enhancing advantages of the single parent separation methods. In this chapter, we briefly introduce the physicochemical background of each method and then review the current state of the development of hybridized surface-based electrochemical ion separation methods and their application to selective extraction of critical and toxic elements with a focus on the most challenging case of low-concentrated solutions.