|Ultra Violet Disinfection compliments our established range of products and services. This publication gives background and technical information to assist with understanding the UV concept and knowledge of the range that is offered.
What is Ultra Violet Disinfection?
There are four types of UV light within the electromagnetic spectrum and they all lie between X-Rays and visible light. The regions of energy that have a germicidal effect are known as UV-B and UV-C.
Figure 1; The Electromagnetic Spectrum
Short-wave UV-C, where the main germicidal effects occur, lies between 200 and 280 nanometres (nm), nanometres being a measure of wavelength. Naturally occurring UV-C is rarely found at the earth’s surface because short-wave UV is screened out by the earth’s atmosphere.
The middle-wave UV-B, existing from 280 to 315nm, provides some germicidal effect if exposure is sufficient. To take advantage of UV’s germicidal potential however, a means of producing UV-C light must be used.
How Effective is UV Disinfection?
Differing types of micro-organism can be more or less sensitive to UV light. This may be because of their cell wall structure, the presence of UV absorbing proteins or the structure of their nucleic acids.
UV is a proven method of controlling microbiological contamination. Some of the features offered by UV as a process are;
These make UV an ideal process for;
*L8 recommends a full water treatment programme including traditional biocides in addition to a full maintenance programme of monitoring along with regular disinfection and cleaning for this type of system.
Figure 2; Typical UV Lamp
How Does Ultra Violet Disinfection Work?
Contamination found in water can be caused by a wide variety of pathogenic micro-organisms. Most are made up of a cell wall, a cytoplasmic membrane and DNA-bearing nucleic acid. Microbes are destroyed when UV light penetrates both the cell wall and cytoplasmic membrane and is then absorbed by the nucleic acids. The UV energy rearranges DNA molecules and prevents the cell from reproducing. The cell is then considered dead for all practical purposes.
Figure 3; Microbial Cell Structure
PWEL offers UV treatment as a microbial control process for humidifiers and air washers where the use of chemical biocides and disinfectants is usually precluded. However, this should only be in conjunction with filtration prior to the UV unit as part of a comprehensive service package which would encompass monitoring (of total bacterial counts, Legionella, and general water quality) and regular cleaning and disinfection, the latter at a frequency determined by the operating conditions. PWEL can provide this complete service on request.
A range of filters is available for effective removal of suspended solids from water entering the UV unit.
Please click icon to download Ultra Violet Disinfection Datasheet
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