Electrochemically driven adsorptive separation techniques: From ions to proteins and cells in liquid streams

Abstract

• Electrochemical separation processes have a great potential beyond ion separation. • Both, faradaic and capacitive current, can be used to separate macromolecules. • The change in surface wetting upon applying electric stimuli is essential for the separation of macromolecules. • Surface plasmon resonance and atomic force spectroscopy techniques will be essential techniques to further investigate electrochemical separation approaches for macromolecules. Separation processes are of utmost importance for most industrial processes in the chemical, food, and pharma sectors. Electrochemical separation technologies gain more and more attention especially for the desalination of water, as they potentially lead to a reduction in the environmental footprint of the process. For salt, many different electrochemical desalination architectures and electrode designs have been proposed. Also other target molecules have been investigated, such as carboxylates, amino acids, proteins and whole cells. We note that the efforts are still scattered; therefore in this review we bundle and summarize the technological state of the art, and the application possibilities for capacitive as well as faradaic separation technologies for various targets. From this it is clear that there are still a lot of options that have been underused so far, and that electrochemical separation processes are key for the separation processes needed for a sustainable future.