Solar Water Purifier

Do you know that you can convert sea water into drinking water using solar energy? Let’s make a simple solar water purifier using things available in the house.

Things needed:

• Large bowl
• Small beaker
• Plastic wrap
• Cello tape
• Small weight or stone

Experiment:

1. Take some water in the large bowl and dissolve some salt in it.
2. Place the small beaker in the middle of the large beaker. The height of the small beaker should be less than the rim of the bowl and larger than the water level.
3. Now using the plastic wrap, cover the top of the bowl tightly. Use cello tape around the bowl to the secure the plastic wrap air tight, if necessary.
4. Place a small weight or stone in the middle of the plastic wrap and above the small beaker.
5. Leave the whole assembly in the sun for a few hour or for a whole day.

Observation:

After some time in the sun, you will notice that water starts accumulating in the small beaker. You can drink the water to check if it is still salty. You will find that the water is pure.

Explanation:

The sun heat the water in the bowl and the water evaporates. The plastic wrap stays cooler since it transmits almost all the sun rays. When the water vapor hits the plastic wrap, it condenses because the temperature of the plastic wrap is less than the Dew point temperature. The condensed liquid slides to the stone and gets dropped into the small beaker.

Try this:

Check if the purified water conducts electricity.