The method by which ions are pulled out of salt water by direct current and employing thin and rigid membrane is called

The method you are referring to is known as Electrodialysis. This technique utilizes direct current to transport ions through selective ion-exchange membranes. In the context of salt water, electrodialysis is particularly effective in desalination processes, allowing for the removal of salts and other impurities.

Here’s a brief breakdown of the process:

1. Ion-Exchange Membranes: The system uses anionic and cationic membranes that selectively allow specific ions to pass through. For instance, the anionic membrane enables the flow of negatively charged ions (anions) while blocking positively charged ions (cations).

2. Application of Direct Current: When a direct current is applied, cations in the salt water move toward the cathode (negative electrode) and anions move toward the anode (positive electrode). This movement is due to the electric field established by the direct current.

3. Separation of Ions: As the ions migrate through the membranes, the salt concentration on one side decreases while on the other side it increases, effectively separating the salt from the water.

4. Result: The outcome is desalinated water, which can be collected for various uses, including drinking and irrigation.

Electrodialysis is recognized for its efficiency and effectiveness in processing brackish and saline waters, and it is widely applied in water treatment facilities.