Solar water disinfection (SODIS) involves exposing water-filled plastic polyethylene terephthalate (PET) bottles to sunlight for several hours. Exposure times vary depending on weather and climate from a minimum of six hours to two days during fully overcast conditions.
Principle of proposed container action
This method uses a conical container with a large closure lid fitted on to it a convex lens(the convex lens is embedded on the closure lid). The container material is clear PET material to allow entry of UV light. The container is filled with water to a specified mark and put under the sun to allow UV action.
The convex lens on the lid has the focal point close to the bottom of the container within the water. The convex lens therefore focuses light rays to produce heat at this focus resulting into temperature gradient thereby creating upward movement of water and hence a continual mixing and gliding of water along the upper surface of the container with stronger light effect. For an illustrative description, view through the link below
• It is a relatively cheap method with no energy input by the user.
• Environmentally friendly
• Highly potable due to light weight