In this experiment, within our experiments at seawe are going to get drinking water from seawater. This way, if you ever get stranded on a desert island, you will be able to get water to drink.
It is a technique in which you will need very few and very simple materials.
MAKING SEAWATER DRINKABLE STEP BY STEP
1. We prepare the materials we are going to need, which are just a container, a black rubbish bag and some stones.
2. Separate the bag into 2 halves
3. Make a hole in the sand, not too deep, about 3-4cm in diameter and slightly smaller than the size of the bags.
4. Place one of the bags in the hole we have made and place stones on top to hold it in place.
5. We take the seawater we are going to make drinkable and put it on the black bag. (Optionally, you can also put it in the black bag. measuring the pH and salinity of seawater before putting it into the drinking water treatment plant. This way you will be able to know the solids it had previously).
7. Put a container in the middle of the water (it can be a cut plastic bottle or a glass).
8. We cover the water we have put in with the other piece of bag that we had cut and we fasten it around with stones.
9. One of the most important parts is to place a stone in the middle of the plastic lid. This will cause the water that will evaporate and condense on the surface of the plastic to slide off and fall into the glass.
10. Depending on how hot it is, wait 2-4 hours. Uncover the plastic and voila! You will have your glass of drinking water.
11. To verify that the water you have obtained is 100%, measure the pH and salinity. Here you can see how to measure ph and salinity of water. In this case the salinity must have been 0, since what evaporates is 100% H2O, neither salt nor any dirt that the water might have, i.e. we have distilled water. The pH of distilled wateris equal to 5.8 (in the link you can see why it is 5.8 and not 7).
MAKING SALT WATER DRINKABLE ON VIDEO
If you prefer, you can watch this step by step video on how to make salt water drinkable. We also recommend you to subscribe to the survival channel with very interesting tricks for survival.
TECHNICAL EXPLANATION
To understand the process we have followed, it is important to note that when water evaporates, the pure H2O particles evaporate, not the rest of the components. That is why this process is about evaporating the H2O water, separating it from the salt, sand and other objects that may be present and then recovering the evaporated water.
The plastic should preferably be black, as black absorbs the sun's rays and will therefore heat up more, helping to further heat the water inside.
The water inside the plastic will heat up and start to evaporate. When it hits the top black plastic, it will condense, forming droplets. Thanks to the stone that we have placed in the middle, the plastic has an inclination and the droplets will fall by weight into the glass that we have placed in the centre.