UV Technology is a non-chemical disinfection technology used globally and extensively here in the Middle East. Many manufacturers would like you to think of it as something of a black art. We at DFT are here to help you better understand how to apply and use this very effective disinfection method.
In our experience many systems are incorrectly specified for 2 reasons. First and foremost is the misunderstanding of the 3 different types of lamp technology available. Secondly, many units are undersized due to some misleading marketing techniques and incorrect sizing of systems that do not take into consideration the required dose and the transmittance requirements of the application and medium respectively. This often, in some cases rather conveniently, is driven by commercial pressure during the writing of the original specification.
The process of UV disinfection is quite simple, water or air that passes through the chamber is exposed to the germicidal UV light which disrupts the DNA of microorganisms. This prevents microorganisms from replicating, rendering them inactive and unable to cause infection.
One of the primary benefits of UV for disinfection is that it does not contain or create any residuals, or byproducts, which occur with chemical methods of purification. In fact, UV is sometimes used to remove residuals and by-products , such as chloramines, peroxide, ozone, and trihalomethanes, that result from other purification processes.
The challenge in specification
Different species of microorganisms require varying levels of UV exposure to be effectively eradicated. Breaking down different compounds, such as trichloramines, within the water also requires exposure to different levels of UV intensity and UV frequencies.
The principle of UV disinfection is often described as a principle of time & intensity. I.e. how long is the water exposed to the UV lamp and what power of UV light is it exposed to. This is an oversimplification and often leads to low pressure systems being specified where medium pressure is required.
Low Pressure or Medium Pressure?
A wavelength of 254 nanometers achieves maximum germicidal effectiveness and is lethal to virus, bacteria and mould spores. Low pressure lamps target the 254nm wavelength specifically, allowing them to be highly efficient. However, medium pressure lamps offer a broader spectrum output between 200 – 600nm, that will breakdown materials that a low pressure system cannot and so it is essential to know the makeup of the media to be disinfected and the application of the system prior to specification.
The applications for UV include but are not limited to:
- Air Extraction Systems
- Swimming Pools
- Drinking Water
- Ponds & Lakes
- Water Features
- Dairy Processing
- Sewage & Wastewater
- SRB Reduction
The correct specification of UV systems and advantages and disadvantages of low and medium pressure systems for particular applications will be covered in further detail in the subsequent publications. If you would like advice before these become available please get in touch at info@owenf.xyz
To see the range of UV systems we have available please see our ultraviolet section here: https://daly-me.com/product-category/uvsystems/