UVoice: definitions explained
To be able to understand each other, we need to speak the same language. We need to use terminology in a uniform way to create a good understanding of what we say, why and how we actually apply it in practice. Speaking a consistent language all members understand and use with the same meaning and context every time is key to get our message across. For that reason, we created a UV Glossary with definitions and explanations of UV-related terms.
We create expert papers in which we share how UV can create value in specific sectors.
We give clear definitions and speak with one UV-language.
We share best practises, insights and case studies, validating findings and comparing them with other existing technologies.
Frequently asked questions about UV disinfection in water treatment
What is UV-C light and what does it do?
UV-C is a powerful form of ultraviolet light that can inactivate microorganisms such as bacteria and viruses. In nature, UV-C light from the sun does not reach Earth; it is fortunately blocked by our atmosphere. But we can make UV-C light ourselves with special lamps. Then it is a very effective and clean technique to disinfect water.
How does UV-C disinfection work?
When UV-C light rays fall on micro-organisms, it damages their DNA. As a result, the microorganisms can no longer multiply and are made harmless. This process is fast and effective, as the water is usually disinfected within 5 to 10 seconds.
How does a UV system work?
A UV system consists of a special UV lamp in a plastic or steel pipe through which water flows. The lamp produces UV-C light that disables micro-organisms in the water by damaging their DNA. In some UV systems, sensors continuously monitor whether enough UV-C light reaches the water and whether the temperature is optimal. The whole process is automatic and without the addition of chemicals.
How do you know if the UV treatment is working properly?
Most UV systems have sensors that continuously monitor whether the system is working properly. A UV sensor measures whether the lamp is still giving enough light. A temperature sensor ensures that the lamp remains at the right temperature (between 15-35°C) for optimal operation. If something is not right, you will automatically receive a warning.
Some UV systems are validated according to European standards. These UV systems prove their performance and guarantee the elimination of microorganisms, as long as the UV system is used according to the designed parameters.
How long does a UV lamp last?
A UV lamp lasts about 8,000 to 16,000 hours. If the lamp is on day and night, this means you need to replace it after 11 to 22 months. The system itself keeps track of how many hours the lamp has burned and warns you 100 hours before replacement is needed. This gives you enough time to replace the lamp on time.
What should I do with an old UV lamp?
UV lamps contain special material and should therefore not be disposed of with ordinary glass. A whole UV lamp should go to the chemical waste at the municipal waste disposal site. Is the lamp broken? Then it belongs in the residual waste, because the special quartz glass cannot be recycled together with ordinary glass. If you want to know more about the recycling process of UV lamps and return options, please check the website of the Open Foundation.
How effective is UV disinfection?
The efficiency of UV disinfection is expressed in ‘log-reduction’. This indicates the percentage of micro-organisms that are removed:
1 log reduction = 90% killing off (1 in 10 survives)
2 log reduction = 99% killing off (1 in 100 survives)
3 log reduction = 99.9% kill-off (1 in 1000 survives)
4 log reduction = 99.99% kill rate (1 in 10,000 survives)
5 log reduction = 99.999% kill rate (1 in 100,000 survives)
For most applications, we aim for an effectiveness of 99.9% (3 log) or more. That last 0.1 or 0.01 per cent that sometimes remains is normal. By comparison, even when using chlorine or other disinfection methods, a minute amount of microorganisms always remains. Most importantly, the water must be safe for its intended use. UV systems are used worldwide in even the most critical applications, such as drinking water production and in hospitals.
Is UV disinfection safe?
Yes. UV disinfection is one of the cleanest ways to treat water. No chemicals are added and no harmful by-products are created. All that happens is that harmful microorganisms are inactivated by the UV-C light. To ensure this safety, it is important to use the UV system according to its design parameters and to carry out annual maintenance.
What does UV disinfection cost?
With a UV system, you mainly have to deal with purchase costs, electricity consumption and replacement parts. The purchase cost of a UV system is usually slightly higher than traditional disinfection methods, but you will quickly compensate for this investment because of the low operating costs. For example, you have no ongoing costs for chemicals, less water consumption and lower maintenance costs. Of course, the exact costs depend on your specific situation.
Use cases of UV technology
