Environmental sustainability and ions removal through electrodialysis desalination: Operating conditions and process parameters

Abstract

Electrodialysis, a membrane separation method, uses an electrical potential difference to separate ions in aqueous solutions. Electrodialysis is used in several industries for the desalination and regeneration of water due to its energy efficiency, environmental adaptability, and flexibility. The applications of Electrodialysis processes are now expanding to include high-purity water production, wastewater treatment, the production of acid and base by water splitting, and the conversion of chemical energy into electricity by integrating various processes. Electrodialysis was originally developed for desalinating water. Its superior water recovery, prolonged service life, and low electrical consumption make it highly recommended in this field. Electrodialysis reversal offers a unique advantage by providing automatic in-process cleaning to prevent calcium carbonate and calcium sulfate scale formation without continuous acid addition or complexing chemicals. Another method is reverse electrodialysis, which reverses the well-known desalination method. A fundamental component of this process is the ion exchange membrane, which enables selective ion transport. In a series and parallel arrangement, ion exchange membranes separate two streams while performing selective mass transport. Electrodialysis also involves electrodes and spacers. Two electrodes are mounted on either end of the membrane stack in order to create a potential difference. Water ionic composition and current supply are the main factors affecting electrode life. Membrane support is provided by spacers. In this study, various aspects of Electrodialysis, including application, structure, membrane types, homogeneous and heterogeneous membranes, electrode materials, spacers, and the application of Electrodialysis to wastewater treatment, are discussed.