Desalination plant

Can we desalinate salted water at home?

We have proposed an investigation related to salted water and done totally at home collaborating between school and families during covid19 close period of our school

Firstly, we've been working about salt and it's characteristics. Then we've evaporated salted water in a plate, and some days later we've created our desalination plant. We've put a plate with some salt water in the sun for a few days and observe any changes that occurred.

Each took notes and photos showing that the power of the sun had evaporated the water, leaving only the salt.

Then pupils were asked to create a small, home made desalination plant. In a large bowl filled with salt water they placed an empty glass in the center. They covered the bowl with transparent plastic and put a stone on top. They then placed it in the sun and observed the effects: the water evaporated, condensing on the plastic. Due to the unevenness that the stone caused in the plastic, the drops from the condensation fell into the glass. So the glass was full of fresh, non salt drops.

We asked pupils to do a research at home, taking notes and photos of the process of evaporation or desalination of water thanks to the heat of the sun.

It so happened that during the first few days of the investigation it rained a lot (this is not normal in our city), and they did not see any changes. From this they learned that external conditions influence investigations.

We've done this investigations as a cross subject activity and language teacher were involved.