The treatment of drinking water and used water with high-energy ultraviolet radiation for disinfection is an environmentally friendly method established for more than 100 years. It works without chemicals such as chlorine or ozone. Special UV lamps supplied by the specialty light sources division destroy microorganisms such as bacteria, viruses and parasites and help decompose chemicals that are detrimental to health. Neither the taste nor smell of the water are affected. The Hanau municipal utilities have been making use of the economic and ecological advantages of this drinking water treatment method for more than one year. To treat the water of a Hanau suburb, they have replaced chlorine disinfection in a water tower with a UV disinfection system supplied by Trojan. The system uses modern and long-life Heraeus amalgam lamps.
Long-life UV lamps enable compact disinfection plants
Due to a special production process, the Heraeus long-life UV lamps enable almost constant disinfection over the entire life of a lamp. Up to 90 percent of the original output is achieved even after a good 16,000 hours of operation, which is almost twice as long as usual commercial UV lamps. Thanks to the higher UV output and long service life, plant manufacturers such as Trojan need fewer lamps to design UV systems for disinfection. Moreover, the systems are low-maintenance and cost-efficient because lamps only need to be replaced after two or three years of operation. This provides a considerable potential for saving as regards number of lamps, system components, energy requirement, service intervals and cost of operation and maintenance. Compact disinfection systems are made possible, which further reduces the amount of space required.
12,000 UV lamps for the Big Apple
The water treatment plant put into service in New York at the end of 2013 is much larger. It is the world's largest UV disinfection system. Some 12,000 UV lamps in 56 so-called reactors, each the size of a truck and likewise supplied by Trojan, treat more than eight million cubic metres of water for the City of New York every day. Heraeus has supplied the initial UV lamp equipment. The water passes the special low-pressure gas discharge lamps and their UV light renders microorganisms innocuous within seconds. With this 'green' disinfection method, the city minimises its expenditure on maintenance and energy consumption for drinking water treatment to guarantee perfect drinking water for the metropolis.
Learn more about specialty light sources for water treatment at www.heraeus-noblelight.com.