Ion-Selective Electrodialysis for Water Treatment Applications: Transport Phenomena in Polyelectrolyte Multilayer Membranes

Ion-selective separations can address important societal challenges, for example, by recovering valuable nutrients from wastewater, making brine streams usable, and removing unwanted minerals from irrigation water. A water technology that can be applied for ion-selective separations is electrodialysis. In electrodialysis, an electric potential difference is applied across special membranes to transport dissolved salts (ions) from one stream of water to another. We explored how ions, like sodium, phosphate, and calcium, move across membranes in electrodialysis and how adding a thin polyelectrolyte coating can improve the performance of those membranes in real‑world applications.