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UV light is a safe and effective means to treat water. ÌýHigh energy photons inactivate pathogens by attacking an organisms nucleic acids (DNA and RNA), denaturing them extensively such that the pathogen can not replicate or cause an infection, and dies off. ÌýUV wavelengths between 200 and 300 nm, with a peak around 260 nm, are most effective. ÌýThese wavelengths are traditionally produced by mercury vapor UV lamps , and new UV LED devices are making UV technology even more versatile. ÌýUV LEDs can be applied to small devices that can treat water at the point of entry and point of use and be integrated into every day products such as water bottles and drinking fountains. ÌýUV can be operated remotely and does not need any chemical input or produce any residuals to dispose of, making it ideal for small and low resourced settings.

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UV treatment is as effective or more effective than other means of disinfection, such as chlorine or ozone. ÌýFurthermore, UV does not affect the taste or odor of water and works in just a few seconds of treatment time. ÌýUV is also effective against pathogens in wastewater effluents and is widely applied for disinfection before discharging water into the environment. ÌýAt higher doses, UV photons can destroy numerous chemical contaminants, and combined with hydrogen peroxide, can form highly oxidative hydroxyl radicals to enable effective control of chemicals of concern.

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Professor Karl Linden, in the Environmental Engineering group and part of the Mortenson Center leadership team, is one of the worlds leading experts in UV-based water treatment research. ÌýCheck out his group's web page . He can be contacted at Karl.linden@colorado.edu