Can one clean water for drinking with solar technology? Living on Earth reports that a very effective and cheap method of using the sun is being used in a number of third world countries with amazing success.
PARTNOW: That's Joseph Otieno, Kenya Water for Health's SODIS project officer. He says all you need is a clear soft plastic bottle.
OTIENO: So you, the first time you get this bottle you clean it. Then you fill it with water, then you close it tightly. Then you expose the bottle to the sun for a minimum of six hours.
PARTNOW: The sun's ultraviolet rays interfere with the metabolism and cell structure of bacteria. And they interact with oxygen in the water, creating highly reactive particles like oxygen free radicals and hydrogen peroxides, which further damage pathogens. Six hours in the sun, and the water is safe for drinking.
SODIS was developed in Switzerland and is now used by two million people in Latin America, Africa and Asia. Test after test has shown SODIS produces sanitized water that easily meets World Health Organization guidelines.
An amazing and surprisingly hopeful story. Although it doesn't clear up chemical or heavy metal toxins, so there is some more work to find cheap techniques to clean up toxins.