How to separate water and salt with an experiment?

In order to remove salinity from water, we use a process known as Thermal Distillation.

Thermal distillation involves heating of the salty water. Boiling water turns it into vapour, leaving the salt behind.

The vapours are collected and condensed back into the water by cooling it down. 

The most common type of membrane separation is called reverse osmosis. This process is also used to remove salt from water.

Seawater is forced through a semipermeable membrane that separates salt from water.