Calgon carbon was granted U.S. patent #6, 129, 843 for controlling Cryptosporidium parvum in water using low levels fo ultraviolet (UV) light.
Cryptosporidium is highly resistant to traditional treatment methods such as chlorination. It was thought that very high doses of UV light, at least 3,000 mJ/cm2, were required to kill Cryptosporidium. Calgon Carbon's research discovered that low levels of UV could be used to prevent Cryptosporidium from replicating by disrupting or crosslinking its DNA and RNA.
This research was used to commercialize the Sentinel UV disinfection system as a reliable barrier against viruses, bacteria and parasites. The Sentinel is an environmentally safe technology that doesn't produce disinfection by-products.
(Source: Calgon Carbon Corp.)