More Deserted Island Water Treatment

For me, fall brings the return of the zombie apocalypse in the form of my favorite TV shows returning to the air. Z-Nation, The Walking Dead, and Ash Versus The Evil Dead all make the coming dreary wet, cold days of fall and winter easier to deal with for me. Accordingly, after having written about using evaporation to make fresh water should we ever be stuck on a deserted tropical island, I have decided to add a second piece to the puzzle.


The risk of being stuck on a deserted Island is so remote, this article is almost silly, but let’s be honest, in these times, more-and-more people like to be prepared and the survival products market is ever-growing. Since the exercise in personal water technology is a good science lesson, I figure what the heck, let’s play it out!

Surviving an apocalypse requires us to be prepared, this is no secret. So, the first adjustment required is that you always have with you an eye dropper bottle full of chlorine bleach, like Clorox™. Chlorine is a powerful oxidizing agent that will drop iron out of water and also kill bacteria on contact. Be careful though because even a little can be too much. One drop from an eye-dropper in 12 ounces of water will keep you safe.

If your deserted island has a stream, pond or lake, it will be smart to disinfect the water before you drink it. The good news is, armed with chlorine, your deserted island will have an unlimited supply of materials for you to build your pwn PDIWTS. This also is a good technology if you collect rainwater since that water will go bad over time.test-tube-yellow

Both coconut shells and clam shells serve as excellent raw materials for making granular activated carbon (GAC). GAC is a universally known filtration media that will remove excess chlorine, as well as harmful organic chemicals and organisms. Simply collect the raw material, grind it into small pieces using rocks, and then roast the hell out of it. The resulting ash, while not as effective as commercially produced GAC, will indeed do the job.

Next, you see all that sand on the beach? It is nature’s sediment filtration media. Grab some, and lets build your filter.

To filter water you will need some type of a tube or column. This can be a pipe, a hollowed out tree limb, a cigar tube, or a pot with a hole punctured at the bottom as a point to collect the filtered water. So, here is how you build your system. Click the PDF at the bottom of the article to see a graphic representation.

  • cover the bottom of your tube with a permeable cloth. (T shirt material is fine)
  • Fill the tube 1/2 way with your carbon ash
  • Top the tube off with sand
  • Pour water through the top, collect at the bottom.

Voila! You are now the professor on Gilligan’s Island.


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