Why Won't Cellular ATP Levels Decrease After UV Treatment?

By Ashlee Donaher

UV treatment has only recently become widely adopted in the water and wastewater treatment industries but the benefits of sun exposure for water purification have been acknowledged for thousands of years. Ancient Sanskrit and Greek writings dating as far back as 4,000 B.C. identify exposure to sunlight as one of the recommended water treatment methods to improve the taste, odor and clarity of drinking water. It wasn’t until the mid-1800’s however, with John Snow’s theory on cholera transmission and Robert Koch’s agar development, that we began to identify microbiological pathogens and the risks associated with them. In 1877, the germicidal properties of sunlight were discovered by Downes and Blunt and, in 1910 in Marseilles, France, the first UV disinfection system for drinking water was operated. UV disinfection was still slow to gain traction in the industry until the 1970’s with the discovery of disinfection by-products (DBPs).