Safety of solar water purification using PET bottles coated with titanium dioxide.

A detailed analysis of the safety of an inexpensive method of water disinfection intended for the developing world is discussed. Plastic PET bottles coated with titanium dioxide are an effective means of water disinfection when exposed to sunlight. A comprehensive literature review is provided which documents the effectiveness of the method in degrading chemicals and killing organisms. Additionally, the degradation pathways of degraded organic molecules are investigated. The safety of the bottle production and of the consumption of the disinfected water along with the photocatalyst coating and dye indicator is carefully scrutinized. A storage experiment showed the effectiveness of the method to resist any regrowth of bacteria for 190 days of storage. A taste test experiment with tasters to differentiate spring water from spring water disinfected using the method showed no distaste resulting from the procedure. Finally, means of microenterprise development are presented to help disseminate the method in the developing world.