Introduction
UV Water Treatment
Water treatment is often regarded as a “black art” by engineers, mainly due to a misunderstanding of chemistry. It also gained a bad reputation due to suppliers being accused of selling a misunderstood commodity that the client would throw away and order more!
This attitude largely changed during the late 1980's and early 1990's due to the efforts of organisations such as the Water Management Society and later the Legionella Control Association.
It was because of this poor reputation that John Fuller, an engineer specialising in evaporative cooling equipment, developed a comprehensive package plant to deal with all the problems associated with evaporative cooling equipment (scale, corrosion and fouling) not the least of which was their association with outbreaks of legionnaires disease.
Based on the well documented biocidal effect of UV light (the biocidal effect of sunlight was discovered in 1880) and researched in conjunction with scientists from the Public Health Service (now the Health Protection Agency) at Porton Down, the UVEX system was issued a patent in 1988.
There being no micro-organisms known not to be subsceptible to ultraviolet irradiation, an understanding of UV will assist in understanding why it is so effective.
Light, like sound, is transmitted by waves. Lightwaves are generated by the sun or from an artificial light source, such as a UV lamp. Light is just a part of the electromagnetic spectrum, of which cosmic rays form one extreme and radio waves the other. Visible light is just one part of this spectrum consisting of different colours and each colour has a frequency. It is the absorption and reflection of the lightwaves that determines the colour our eyes see.
The word Ultraviolet (UV) means "beyond violet" and is derived from the Latin word ultra, meaning beyond. Violet is the colour of the shortest wavelengths of visible light.
Ultraviolet (UV) is light that we cannot see as it has a wavelength shorter than that of visible light.
UV can be subdivided into three different types:-
UV-A - Near UV (400-320 nm wavelength)
UV-B - Far or vacuum UV (320-280 nm wavelength)
UV-C - Extreme UV (>280 nm wavelength)
It is UV-B light at its biocidal wavelength 185 and 254 nm that is absorbed by DNA, the basis of all life, breaking the essential links between the well known “double helix” configuration.
Having its links broken the organism cannot metabolise and therefore dies. The effect is almost instantaneous - less than 1 second
A UV lamp operating at 254 nm with an output of over 10 times the known amount to give a 99.9% kill of legionella is used in System Uvex UV water treatment to destroy the DNA of potentially damaging micro-organisms, including bacteria and viruses, rendering them harmless.
This coupled with continuous circulation, 25 micron filtration, conductivity control with its unique Bleedclean TM operation, fault protection devices and “logging” facilities provides the most comprehensive non chemical water management package available.
Overview
The water treatment solutions available from System Uvex comprise a method to manage evaporative cooling (and other) water, by applying filtration, irradiating with intense UV light, and controlling the chemical constituent (TDS) by passing it continuously through the system unit (at least once an hour), to attain the highest possible quality in use.
System Uvex water management provides a natural, simple, cost effective solution for organisations that need to ensure the water they use is safe from unseen hazards and of a quality that complies with relevant legislation.
System Uvex is a natural choice for companies who are keen to demonstrate their positive attitude towards the environment by adopting environmentally friendly processes wherever possible.