When most people hear the term UV radiation, sunburns are the first thing that come to their minds. Ultraviolet is a type of energy in the electromagnetic spectrum, placed between x-rays and visible light. And, yes, we are exposed to UV rays every time we go outside and it can cause sunburns, but they can also be used for good purposes. It’s also used as a disinfection method for food, air and water. As a matter of fact, UV water purification systems are becoming a broadly popular option so here’s what you need to know about it.
How does it work?
Ultraviolet germicidal irradiation is a disinfection method able to kill or inactivate various microorganisms. It uses short-wavelength ultraviolet light and became an accepted practice since the mid-20th century. The UV light comes from special lamps which are an integral part of the UV filters. The lamps, of course, never come in contact with water – they’re either protected in quartz glass sleeves or mounted on the external side of the UV purification unit.
Those lamps produce UV radiation at 254 nm, which is the optimal wavelength for disinfection. As water goes through the filter, the light disrupts the DNA of microorganisms. The effectiveness of this method depends on the length of time a microorganism is exposed to the UV rays, the intensity of the rays and the microbe’s ability to resist the rays. The process affects the microorganism’s ability to reproduce, making them inactive, but it doesn’t remove them from the water.
What are the advantages of this method?
In comparison to other water disinfection systems, UV purification is affordable and doesn’t need a trained professional to install it. In terms of primary energy use, UV filters are multiple times more efficient than the most reliable water disinfection method – boiling. In addition, quality UV water filters require very little maintenance – it’s enough to check them once in a year to change the UV bulb.
Besides its cost-effectiveness, UV purification systems are environmentally-friendly as well, since there are no byproducts released during the process of disinfection. Also, there are no harmful chemicals included and, because of that, it won’t change the taste or the odor of your drinking water, unlike chlorine. It can combat 99 percent of viruses, bacteria, and protozoa – so you won’t have to worry about pathogens like Escherichia coli, salmonella, polio, cholera, dysentery, and other more or less life-threatening contaminants.
What are the limitations of this method?
Regardless of how effective UV water treatment sounds the fact is that it’s only able to eliminate waterborne microbial pathogens. It cannot remove heavy metals, salts or minerals. Therefore, UV filtration systems are usually combined with other methods, usually with reverse osmosis filters or carbon block filters. That being said, UV purification does not work if the water is murky since it can’t remove “floaters” and other particles. Once again, another filter or some kind of “pre-filter” is a must.
Regardless of how energy-efficient it is, this method still needs electricity to function so that makes it unsuitable for rural areas or emergency and survival needs. UV treated water is not resistant to reinfection, unlike chlorinated water, since it doesn’t provide the residual germicidal effect. Besides, there are no guarantees that 100 percent of bacteria will be eliminated, so the water systems disinfected by UV treatments must be treated with chemicals (usually chlorine or hypochlorite) every once in a while. That’s the only way to be sure your water and pipes are sanitized.
In conclusion, UV purification systems make an excellent choice due to their efficiency, cost-effectiveness and low maintenance needs, but you should be aware of the limitations as well. They work best when combined with other purification systems, so get your facts straight, think it through and see what’s the best option for your household or business.
Article written by Lillian Connors. If one thing is true about Lillian Connors, her mind is utterly curious. That’s why she can’t resist the urge to embark on a myriad of home improvement projects and spread the word about them. As the Co-Editor at SmoothDecorator, she cherishes the notion that sustainable housing and gardening will not only make us far less dependent on others regarding the dwellings we inhabit and what we eat, but also contribute to our planet being a better place to live on. You can check her out on Twitter and LinkedIn.