UVC LED Technology

Welcome to the 
world of UV
What is UV?

UV is part of the electromagnetic spectrum. We enounter it often coming from our planet”s ultimate source of energy – the sun.

UV or ultraviolet (literally “beyond violet”) is at and beoynd the higher energy border of visible light. UV waves are invisible and were discovered in 1801.This was the first time that a form of light beyond visible light had been detected. A new scientific era was born.

UVA & UVB are omnipresent in the atmosphere. The latter giving you sunburn and also vitamin D. Thankfully, the higher energy power of UVC does not enter earth’s atmosphere thanks to the ozone layer. We are protected, and that is perhaps why living organisms have not learnt how to protect themselves from UVC.

Watersprint’s technology – as older mercury lamps- operates within the UV-C spectra with wavelengths ranging from 100 nm to 280 nm.
LEDs are typically placed in the end of this range 265-275 nm.

The UV light is classified into four sub-groups with increasing energy:
UV-A, UV-B, UV-C and Vacuum UV.

Beyond these, we encounter x-rays and gamma-rays.

UV distorts and breaks DNA’s structure, introducing bends and odd shapes rendering the usual transcription and reproduction impossible. As a concequence, self repair is no longer possible and the bacteria dies.

UV Destroys DNA
How does UV disinfect?

UVC disinfects by ”shooting” energy (photons) into cells of bacteria, virus or other pathogens, causing significant damage to their DNA and RNA.
The DNA spiral, basically, gets broken down beyond recognition.

The famous double helix structure (its discovery also awarded Nobel Prize in 1962) is usually highly resilient and capable of self-repair, but UV inflicted damage is beoynd this capability.

Once the ability to replicate and reproduce is blocked, even though bacteria is still present, it is deactivated and no longer a threat to human health.

Today all parts of the UV spectrum find use in an ever increasing variety of applications – from dentistry to forensics, in industry, curing resins, and in food, water, air & surface disinfection. Combinations are endless.

Revolutionary

Why is LED a revolutionary technique?

For a century, UV lamps have served mankind extraordinary well. 

However, these lamps have serious flaws. One is the dependency of mercury (Hg) to generate germicidal light. This poisonous heavy metal is now being restricted globally for environmental and health reasons. 

In contrast, LED generates germicidal light without the use of mercury or any other hazardous chemicals or materials. This is revolutionary, and was awarded the Nobel Prize in Physics 2014..

Today, UVC-LED is the best and most cost effective way handling flows up to 20 l/m (liter/minute). For example, we are able to disinfect 5 l/m – typically max flow from tap – at above Log6 reduction (99,9999%) of bacteria, protoza, virus, cysts etc.  

In addition, different bacteria have different “sweetspots”. LED makes it possible to tune the wavelengths according to microbial sensitivity giving more flexibility 

There will be microbiological performance certification available. NSF/ANSI 55-2019 Standard has recently been updated to address the unique technical differences of LED technology compared to traditional mercury gas-discharge lamps.  

Link: www.nsf.org/newsroom/major-revision-drinking-water-treatment-standard-allows-uv-led-technology

Germicidal effectiveness – “the killing sweetspot”- is recognized as being between wavelengths of 260-280 nm (nanometer).

Mercury produces 254 nm which is just outside the sweet spot and is therefore sub-optimal. LED covers the germicidal sweetspot for maximum disinfection much more effectively (top graph).

 

 

 

Log reduction – Kill rate- of our different products at different flows.
Log reduction is explained below.

LED vs lamps?
How does LED compare with mercury lamps?

Besides being free from active chemicals, LED is simply a better and more advanced technology. This includes being IoT-capable, robust and shock resistant, needing significantly less maintenance and replacements, having a superior heat management and unlimited on/off cycles. The list is long, and growing.

Nonetheless, LED also has its weaknesses. Handling continous 24/7 flows, for example, will shorten the lifespan of the LED’s. Also, although larger “non-point of use” flows can be handled today, it is currently less common due to cost efficiency.

However, rapid development is closing in on adressing both challenges with continuous 24/7 flows and high volume disinfection.

LED vs other technologies

There are numerous other techniques available for disinfecting water. Besides boiling, different physical filters are most common. Filters are generally easy to use, often inexpensive and function reasonably well.

However, even the most exclusive filter can not block all bacteria nor smaller viruses. Filters clog easily if not replaced frequently, which increases the risk of post disinfection contamination.

Of course, there are also a host of different chemical methods. The most commonly used chemicals include ozone, chlorine and some of its compounds, hydrogen peroxid and potassium permanganate.

The best known technique, chlorination, has been used for almost a century. However, formation of mutagenic and carcinogenic agents in water treated with chlorine has prompted research to seek alternative disinfecting methods that would minimize environmental and public health impacts.

Boiling together with different physical filters are most common method of disinfecting water around the globe.  

UV LED, sometimes in combination with other techniques depending on cirumstance, provide best safest possible protection. Other strong advantages are its capability to be places where other techniques cannot combined with Internet of Things capabilities.