Solar Water Treatment
Yes that guy really is putting bottles on his roof....Solar water disinfection (SODIS) is a low-technology, simple process of purifying water using the power of the sun’s UV rays and solar radiation. SODIS technology was first introduced in 1980 by Aftim Acra et al. from the American University of Beirut. The initiative to spread SODIS in developing countries began with the Swiss Federal Institute of Science and Technology (Eawag) in 1991. Currently, the technical team at Eawag helps support projects in 24 countries through partner organizations in order to ensure more safe drinking water worldwide.
The method for SODIS involves clear PET (polyethyleneteraphtalate) bottles and a location that is exposed to the sun, most commonly the roof top of a residence. The size of the bottles should be 2 liters or less, and the water is filled in the bottles to leave 2.5 cm of space in order to permit enough oxygen for the process, then shake the bottle of water to fully oxygenate the
water The process involves exposure to the UV-rays and temperature, the higher the temperature the water reaches in the bottle the faster the disinfection process. If it is sunny or up to 50% cloudy, the water is disinfected in 6 hours of exposure. If it is 100% cloudy then the bottles need to be exposed for 2 days. If water temperature goes above 50 ͦ the disinfection process is complete in 1 hour. After this time period, the water is disinfected and ready to drink. These simple calculations of sunlight and temperature make this method of water purification very accessible...
I know it gets hotter than hell in Florida, that you guys have strong sun, so maybe this can be an option at least some of the time. :)Solar water disinfection - the SODIS method - is a simple procedure to disinfect drinking water. Contaminated water is filled in a transparent PET-bottle or glass bottle and exposed to the sun for 6 hours. During this time, the UV-radiation of the sun kills diarrhoea generating pathogens. The SODIS-method helps to prevent diarrhoea and thereby is saving lives of people. This is urgently necessary as still more than 4000 children die every day from the consequences of diarrhoea...