Brighter Light Better Water

While most people in the developed world have safe drinking water continuously supplied to their homes, more than half of the world’s population is exposed (подвергать опасности) to water contaminated (заражать) with pathogenic organisms.

Environmental physicist Ashok Gadgil and colleagues at Lawrence Berkeley National Laboratory are working to develop a simple and effective device that can greatly reduce (уменьшать) people’s risk of becoming infected through the water they drink. The device, named UV Waterworks, is a grocery bag-sized stainless steel box containing a low-pressure mercury vapor lamp like those used in fluorescent lighting found in most office buildings.

The simplicity of the device is one of its strongest attributes. Because its major components are common and inexpensive, UV Waterworks is cheap to build and easy to maintain. The UV lamp, which will burn for about 8,000 hours, must be replaced yearly, but otherwise the device requires almost no maintenance. Water flows through the device by gravity, and electricity is used only to generate the UV light. With a total power demand of just 40 watts, UV Waterworks can operate connected to a car battery or a 2 m² photovoltaic panel, and can disinfect 15 liters (4 gallons) of water per minute. Water Health International, the company that will manufacture UV Waterworks, estimates that when used to supply a community (община) of 1,500 – 2,000 people, the total cost of disinfected drinking water would be about fifteen cents per person annually. This makes it affordable even by developing world standards.

From “Innovations”