A Person is Stranded Near Salt Water. Here’s How He Can Make it Easy to Drink.


As you're about to find out, the process of desalination is not that difficult, nor is it all that expensive. Once you've mastered this useful life-saving skill, you can impress your friends by showing them how to do it themselves! Learn about the science of desalination as well as how to create a solar still to ensure safe drinking water.

Desalination is not modern science

Desalination/distillation is one of mankind's earliest forms of water treatment, and it is still a popular treatment solution throughout the world today. In ancient times, many civilizations used this process on their ships to convert sea water into drinking water. Today, desalination plants are used to convert sea water to drinking water on ships and in many arid regions of the world, and to treat water in other areas that is fouled by natural and unnatural contaminants. Distillation is perhaps the one water treatment technology that most completely reduces the widest range of drinking water contaminants.

In nature, this basic process is responsible for the water (hydrologic) cycle. The sun supplies energy that causes water to evaporate from surface sources such as lakes, oceans, and streams. The water vapor eventually comes in contact with cooler air, where it re-condenses to form dew or rain. This process can be imitated artificially and more rapidly than in nature, using alternative sources of heating and cooling.

Your own personal desalination plant
Remember looking at the picture at the top of this page of a floating solar still? The same process that drives that device can also be applied if you find yourself in the desert in need of a drink of water.

The low-tech approach to accomplish this is to construct a “solar still” which uses heat from the sun to run a distillation process to cause dew to form on something like plastic sheeting. The diagram to the right illustrates this. Using seawater or plant material in the body of the distiller creates humid air, which, because of the enclosure created by the plastic sheet, is warmed by the sun. The humid air condenses water droplets on the underside of the plastic sheet, and because of surface tension, the water drops stick to the sheet and move downward into a trough, from which it can be consumed.

solar still

via turbinegenerator.org / Water Education Foundation

You never know when you may have to go through a SHTF situation that requires you to create safe drinking water from salt water. Whether you're surrounded by a lake or the ocean that has salt, it's imperative to make sure you follow the proper steps to ensure safe drinking water.

If you enjoyed reading about the desalination process, you can find out more at Water.USGS.gov for more information about making water safer to consume.