Processes like Sand Filter /Ultrafiltration / Reverse Osmosis are the pressure driven process, whereas electrically driven approach encompasses electro-dialysis & electro di ionization. This Electro di Ionization process is generally applied when aim is to remove the ions (Cation & Anion) from water, & this is been achieved through the selective control & transport of ion species.
The fundamental principal behind electrically driven process is the passage of ions through a selective barrier (Ion Exchange Membrane) due to driving force (Electric field). Ion Exchange membranes play a critical role in this process & they are responsible for accepting & rejecting ions in the establishment of dilute & concentrate compartments. Electro di ionization is the process that based on selective migration of ions in solutions through the ion exchange membranes under activation of electric field.
This is a continuous process (Generation of process water as well as online regeneration) hence the same is also called as CEDI Technology (Continuous De Electro Ionization) CEDI is the most popular technology for electrically driven process in industries (Pharma Sector / Power Sector) as it separates the undesired ions from aqueous solutions at low operational cost & with the advantage that it does not generates the residues.