What is electrodialysis?

Hint: Electrodialysis may be a sort of dialysis during which undesired ions are faraway from solution by means of an immediate current passing between two electrodes, one on all sides of the membrane. it's wont to desalinate or concentrate a liquid process stream containing salts.

Complete answer:
It is a process by which colloidal solutions containing ionic impurities are purified. The sol containing ionic impurities is placed during a bag of parchment paper in water . The ions begin through parchment paper and therefore the sol is purified.
Electrodialysis may be a membrane process that uses alternating Anion–selective membranes (AMs) and Cation-selective membranes (CMs), placed between an Anode (+) and a Cathode (-). Thanks to the applied field , anions will move towards the Anode and cations will move towards the Cathode.
Electrodialysis is applied for the removal of dissolved ionic substances from water. Amongst other desalination processes, like natural process , nanofiltration and reverse osmosis, the most advantages of electrodialysis are high water recovery, selective desalination, low chemical demand and low energy demand. This chapter describes the appliance of electrodialysis for the removal of nitrate and hardness from groundwater. Experiences with a full-scale plant are presented. As a second feature, pilot tests using electrodialysis at an integrated membrane system for surface-water treatment are described.

Note:
Electrodialysis (ED) is employed to move salt ions from one solution through ion-exchange membranes to a different solution under the influence of an applied potential difference. This is often wiped out by a configuration called an electrodialysis cell.