What process involves transferring ions through a membrane due to an applied electric current?

The process that involves transferring ions through a membrane due to an applied electric current is electrodialysis. In electrodialysis, an electric field is applied across an ion-selective membrane system, which causes positively charged ions (cations) to migrate towards the negative electrode and negatively charged ions (anions) to migrate towards the positive electrode. This movement of ions results in the separation of salts from water, effectively desalting the water or concentrating certain ions.

This technique is particularly valuable in applications such as water treatment, where it can efficiently remove dissolved salts and other impurities from water sources. The success of electrodialysis relies on the properties of the membranes used, as they selectively permit the passage of specific ions based on their charge.

Other processes do not involve the direct application of electric current to facilitate ion movement in the same way. Nanofiltration and reverse osmosis are membrane filtration processes that rely on pressure to separate particles and solutes from water but do not use electric current for ion transfer. Electroporation, while related to the application of electric fields, refers to the process of temporarily disrupting cell membranes to allow substances to enter or exit the cell, rather than transferring ions through a membrane for separation purposes.