Legionella are small gram-negative rod-shaped bacteria. Over 40 individual species of Legionella are known. Most of the human infections are caused by the species Legionella pneumophila. Legionella pneumophila was first discovered following a pneumonia outbreak at the 1976 Convention of the American Legion in Philadelphia Legionella is found everywhere in the environment and is a natural inhabitant of water. It can also infect other organisms to improve its chances of survival. Once inside its host, Legionella can multiply quickly and produce more bacteria. Being inside another organism also protects it from being killed when water is disinfected in water treatment plants. Legionella grows well in warm, still waters that are found in: cooling towers, evaporative condensers, humidifiers, air washers, mist machines, hot water heaters, whirlpool spas, fountains, hot springs and plumbing fixtures. It has been found in water with temperatures ranging from 6-60°C (42.8°F-140°F) but will not multiply below 20°C (68°F) and will die above 60°C (140°F). The major sources of Legionella are the water distribution systems of large buildings including hotels and hospitals.
Inhaling small aerosol particles that contain Legionella is the most popular theory of how people get infected with legionellosis. The aerosols often come from mists created by a water source. People may be exposed to these mists in homes, workplaces, hospitals, or public places. Legionella lives in both natural and man-made water sources and the presence of other organisms in the water will help it survive and multiply. Because of this, Legionella is able to live in drinking water supplies. Gaining access to drinking water sources will help it multiply and spread. Groundwater is also at risk of being infected with Legionella and hot springs have shown to be a natural source of the bacteria.
The use of UltraViolet (UV) light to kill Legionella is well documented, and the bacteria is relatively easy to kill with an adequate UV dose applied to the water in such systems. UV works to destroy the bacteria almost instantly while the water is exposed to germicidal wavelengths of UV light inside a sealed UV chamber. The process is completely chemical-free and there is never a risk of UV overdose.
Legionella Home Treatment System
Ultraviolet (UV) light treatment process involves inactivation of drinking water pathogens or the oxidation of micropollutants. During the oxidation process, it is commonly used in combination with hydrogen peroxide as a part of an advanced oxidation process. UV disinfection or oxidation is a physical process that utilizes UV light and does not require use of any chemicals. This technology is very effective for germicidal properties mainly inactivating microorganisms (i.e. bacteria, viruses, algae, etc.) including chlorine-resistant pathogens, such as Cryptosporidium. Because of safety issues associated with the reliance of chlorination and improvement in the UV technology, UV has experienced increased acceptance in both municipal and household drinking water treatment systems
Product Specification – Pelican UV Systems – PUV-8 and PUV-16
The Pelican UV systems come in two different flow rates – 8 and 16 gpm. Some of the features of this system are listed as follows:
- 9-16 GPM peak flow – Ideal for most homes
- Does not affect taste, color and odor of the water
- Capable of destroying 99.9% of harmful microorganisms including: E. coli, Cryptosporidium and Giardia
- Easy to maintain
- Safer disinfection process without the use of harmful chemicals
- No disinfection by-products
- Fast acting
- Effective against a broader range of organisms than chlorine
- Best warranty on the market
The model specifications for PUV-8 and PUV-16 are summarized in table below:
The consultants and Water Expert at Saniwater can help address the questions and concerns of their customers pertaining to the UV treatment system from PENTAIR: PELICAN manufacturers. They offer dedicated excellent customer service. The specialized and highly trained staff of technicians will not only help install the recommended product but also help troubleshoot if necessary.
REFERENCES
- https://www.epa.gov/sites/production/files/2015-10/documents/legionella-factsheet.pdf
- https://www.cdc.gov/legionella/about/causes-transmission.html#:~:text=People%20can%20get%20Legionnaires’%20disease,into%20the%20lungs%20while%20drinking.
- https://preventlegionnaires.org/did-you-know/
- https://www.safewater.org/fact-sheets-1/2017/1/23/legionella
- https://www.wyckomaruv.com/blog/blog-post_UV-Water-Treatment-to-Kill-Legionella.html#:~:text=The%20use%20of%20Ultra%20Violet,the%20water%20in%20such%20systems.&text=The%20process%20is%20completely%20chemical,a%20risk%20of%20UV%20overdose.
- https://www.pelicanwater.com/uv/pelican-uv-premium/
- http://www.nsf.org/consumer-resources/water-quality/water-filters-testing-treatment/home-water-treatment-system-selection
- https://www.cdc.gov/healthywater/drinking/home-water treatment/household_water_treatment.html
- https://iaspub.epa.gov/tdb/pages/treatment/treatmentOverview.do?treatmentProcessId=-2054608628#:~:text=UV%20disinfection%20or%20oxidation%20is,resistant%20pathogens%2C%20such%20as%20Cryptosporidium.
- https://www.water-research.net/index.php/water-treatment/water-disinfection/uv-disinfection
