How to Remove Salt From Filtered Water

People use water filters to create soft water for drinking and other uses. Filtration systems use a variety of methods to soften water, including biological processes, ion exchanges and filtering water through fine materials such as carbon. But even filtered water can have some minerals remaining, including salt. Here are methods to remove salt from filtered water.

Instructions

• 1

  Bring water to a boil in the chamber of a distiller. Let the water vaporize. The steam leaves behind the nonvolatile substances that may have contaminated the water, including salt. The vapor rises to a condensing coil in the system and is condensed. This condensed water then drips into the storage container and is now free of salt.

• 2

  Apply reverse osmosis to remove salt from water. This process applies pressure that exceeds the osmotic pressure and the fluids are pressed back through the osmosis membrane, leaving dissolved solids behind.

• 3

  Put the salty water into an electrodialysis (ED) cell. The ED cell has a membrane that separates the mixture into two streams, a concentrated stream and a dilute stream. Apply an electric current to the system, which will cause salt ions to move to the concentrated side of the cell through the selective membrane, leaving pure water on the other side. This process is popularly known as electrodialysis.

• 4

  Flow water over a rotating drum cooled below the water's freezing point. The water freezes, and since ice has a very complicated crystal structure, it prevents inclusion of most salts in its crystals. Rinse off the purified ice water that has formed. This is efficient for water that is not too salty.