Swede Petra Wadström has invented a device that uses solar power to purify water for drinking. The device, called Solvatten, looks like a jerrycan and can take up to 10 litres of water. When the device is left in the sun, an indicator turns from red to green to show that the water temperature has reached 55°C and the water is safe to drink. According to the Solvatten web site, water samples with more than 200.000 E. coli/100 ml have been successfully treated. A Solvatten device costs US$ 35 (€ 27) and lasts at least five years or more. At a rate of 10 litres of water a day for 300 days a year, the cost per litre is 0.2 US dollar cents.

'People are living with dirty water around the world and children are suffering from bad water, which is easily preventable, but people are living with a lot of solar energy and not using it,' said Ms Wadström. Tests in Kenya and Nepal have produced positive results and feedback. In 2009, there will be a user study in Nepal involving families, schools and health centres. The programme is being implemented in collaboration with UN-HABITAT and the Environment and Public Health Organisation (ENPHO).

Related news:

• Drinking water: more affordable treatment with ultraviolet light, Source South Asia, 10 Feb 2009;
• Terafil water filters: clay filters promise clean drinking water in villages in Jharkand, India, Source South Asia, 23 Jan 2009.

Web sites:Solvatten; UN-HABITAT; ENPHO

Source:edie, 12 Jan 2009

Tags: technology, water treatment