If you ever find yourself in a situation where water drinking water is scarce yet salt water is more abundant, you’ll need to know how to convert salt water to potable water, also called desalination.
Why not drink salt water? The human cells have membranes that prevent salt from roaming throughout the body which normalize our sodium levels. However, if the salt concentration is higher on the outside than inside of our cells, water will move from the inside to the outside of our cells to correct the imbalance. This causes the cells to shrink and our bodies to dehydrate quickly. In essence, by drinking salt water you are causing your body to dehydrate faster than it would if you had not consumed salt water. Don’t do it!!
There are many ways to create purified water from salt water, but the easiest way is to use heat. Turning the water into steam leaves the salt behind and creates water that is drinkable.
There are several methods to collect this water. Two are listed below.
Desalination 1: Thermal Distillation
Items: heat resistant container (metal pot), lid for pot- or aluminum foil, and a heavy cup
- You will fill the pot about half full of salt water
- Place the cup in the center of the pot in the water. The cup should be heavy enough to sit on the bottom of the pot and not float on the water.
- Place the lid or aluminum foil over the top of the pot (if using foil- make a dome shape over the top to allow the water to collect over the cup
- Put the pot on a heat source that will evaporate the water
As the water heats, it will become vapor and condense over the cup until water droplets form and fall into the cup which will fill with clean drinking water.
Desalination 2: Solar Distillation
Items: bowl (heat or non heat resistant), heavy cup or container, plastic wrap
- Fill the bowl about half full of salt water
- Place the cup or container in the center of the bowl in the water
- Place the plastic wrap tightly around the top of the bowl, as to not allow vapor to escape
- Put the bowl in sunlight to evaporate the water
This method, as I’m sure you’ve guessed, will take much longer than the thermal method. But if you do not have a heat source this method works just as well.
2.2 You can also use this method with a water bottle and a soda can or cup. See video below