From the slums of Nairobi to the most remote corners of the Andes, clean water is a necessity. But without significant investment in sanitization infrastructure, this resource is incredibly difficult to provide. But after years of research and development, a cheap, reusable and nearly universally effective system of water treatment has been developed.
It’s called SODIS which stands for Solar Water Decontamination, and requires only a source of fresh water, a clear plastic bottle and sunlight. It sounds impossible, but the science behind it is solid. Sunlight contains a great deal of ultraviolet radiation, which disrupts the genetic processes of bacteria reproduction and can destroy the microorganisms cell walls. Ultraviolet radiation also has an ionizing effect on the water itself, creating highly oxidative compounds like hydrogen peroxide, a common household antiseptic. While it may be difficult to believe, all it takes is six hours sunlight to destroy the microbial inhabitants of a bottle of water, rendering it fit for human consumption.
As you can see, not only is this water purification process useful to the peoples of third world countries but, it is also beneficial to the wilderness traveler and survivalist.