Distillation does a good job of removing many contaminants and pathogens. It removes dirt, bacteria, viruses, and protozoa. It also removes metals such as lead, copper, and sodium. Distilling removes many things you are likely to Replace in the water, but not all. If something vaporizes at a lower temperature than water e.g. alcohol or gasoline, it will come out in the distillate. This means that distillation is not going to be useful for chemical contamination, especially in a do it yourself situation.
DIY Solar Still InstructionsHere’s what I did and what I learned when I made my own solar still. I decided to try a couple techniques for making a solar still that could apply in two different situations. Both techniques use the same materials. Materials: The Sun Bowl (about 12 inches in diameter, preferably larger) Mug or Plastic container (think Tupperware) Plastic Wrap or Sheeting A Weight (a rock, brick, box—anything heavy you can Replace to hold down the plastic wrap down) Shovel (or a tool or rock that can dig a hole) Plant Material (shrubs, grass, leaves, etc.)
Solar Still #1: Coffee-Mug StillFor the first one, I assumed a situation such as an earthquake or flood that leaves you in your home (sheltering in place), but causes a disruption in utilities. While normally you would have safe drinking water stored, in the event that you don’t—or it somehow became contaminated, you may need to make a simple solar still. What I did:
- I put salt water in a bowl that is about 12 inches in diameter. I then put a coffee mug in the center of the bowl. I placed the bowl on a table, directly in the sunlight.
- I covered the bowl in plastic wrap and put a weight on the center above the mug to direct the condensation toward the mug. All that was left was to put it in the sun and wait.
- The contaminated water went into the bowl, then the condensation on the plastic wrap drips into an empty mug in the center, filling it with clean water.
Solar Still #2: Pit-Style Solar StillThe second method I used was more of a survival technique. You might use this type of solar still if you have to evacuate your home in an emergency and live off the land. What I did:
- I dug a shallow hole in my garden about 3 feet in diameter.
- I then filled the hole with plant material and placed a water collection cup in the center.
- Similar to the set-up described above, I once again covered the collection cup in a plastic sheet.
- I then placed a rock in the center to cause the condensate to run to the middle and drip into my collector cup.
I did this on a hot sunny day, for the entire day, and collected around one third of a cup of water.