An overview of ultraviolet light advancements & the technology’s future
Ultraviolet (UV) light technology for disinfection has seen a massive surge of interest in 2020. The evidence that UV can be deployed for air and surface treatment on a broad scale to inactivate SARS-CoV-2 (the virus that causesCOVID-19) is new to many and wholly unsurprising to those already working with the technology.
The concept is simple. UV photons penetrate a cell wall to disrupt the DNA and render the pathogen inactive, or unable to replicate. These photons are produced by specialist lamps and configured into different delivery systems depending on the application: air, surface or water.
Examples of all three of these applications can be seen as far back as the early 1900s; however, widespread commercial use of UV as a disinfection technology really started in the 1970s, with huge growth in water and wastewater applications in the 1990s and 2000s.
Initial key growth areas were drinking water in Germany and Austria and wastewater in the U.S. The growth drivers included the reduced need for chemical additives with their related byproduct generation risk, absence of pathogen resistance (e.g. Cryptosporidium is difficult to inactivate with chemical treatment) and ease of operation.
Ultraviolet technology is now established as a key disinfection tool globally across a broad range of water and wastewater applications, and with it there is an established supply chain of component and system manufacturers, together with (mostly) clear regulations on the design and operation of the technology. There have been new growth areas in healthcare, food processing and reuse water in recent years, though on the whole UV has experienced a pleasant growth trajectory over time.
The emergence of COVID-19 in 2020 has somewhat upset the UV apple cart. Technical and business interest from large corporations and entrepreneurs alike have flooded the application space. Some have already been working with UV technology and have expanded their application range to specifically address COVID-19 related problems. Others entered the market from adjacent applications, such as general lighting suppliers seeking to implement UV light sources into products. Yet others, often as a result of becoming unemployed or under-employed, have become interested in providing solutions from completely outside of the space.
This rapid change has strained supply chains to the detriment of existing water treatment interests. Particularly the manufacture of the specialist mercury-vapor UV lamps have seen a massive increase in demand, thus leading to longer delivery times and increased pricing.
These lamps typically require annual replacement, so assuming the COVID-19 related products will be operated for the foreseeable future, this situation will continue until manufacturing capacity increases. Conversely if demand falls off in 2021 and beyond, will excess capacity become an inverse problem? Only time will tell.
Alternate light-sources such as UV-C LEDs and Excimer-based UV lamps were emerging as alternatives long before 2020. However, partly related to the supply constraints and partly due to a broader range of application uses, these have accelerated growth.
These alternate light sources, particularly UV-C LEDs, have started to benefit from significant increases in manufacturing scale and together with a trend of increased performance, they are finally being implemented into large scale commercial products.
AquiSense Technologies of Kentucky recently announced a major supply contract with Mitsubishi Electric Corp. of Japan for the supply of a bespoke UV-C LED product for disinfecting greywater in a residential application thought to exceed more than 100,000 units per year.
The ability of UV-C LED technology to technically and commercially outperform conventional UV mercury-vapor technology in such an application is likely a bellwether for 2021 and beyond. Not only are there predicted to be a slew of similar sub-20 gpm applications established, but there are also now commercially available point-of-entry (POE)UV-C LED systems and a number of small-scale municipal pilot systems in operation. The engineering and operational flexibility of UV-C LEDs make them an attractive proposition.
Another alternate UV light source that has gained a lot of attention is an excimer-based gas-discharge lamp producing wavelengths in the 200 nm range, or so-called “Far-UV”. Although not a new technology, it has gained attention from studies indicating human skin safety exposure, which has always been a limitation of conventional UV-C technology in the 250 to 280 nm range.
While these lamps may have limited applications in water applications, which tend to be enclosed, it will be interesting to see if they can increase in efficiency and reduce in cost, to act as a mercury-free alternative to gas discharge UV lamp technology.
As mentioned earlier, one of the key drivers for the establishment of UV technology within the water and wastewater industry is existence of standards, regulations and guidelines. This largely does not exist for air and surface solutions applying the use of UV technology, which has somewhat become the wild-west as providers have sought fast solutions to keep offices, public spaces and personal environments safe. From hardware design, to measurement verification and validation standards, the water treatment industry has solved a lot of problems currently pondered in other circles.
It is interesting that established water treatment suppliers do not appear to have capitalized on that advantage. It appears that UV water system manufacturers have largely stayed within their lane and have not expanded into air and surface applications. Why is that? Do they have enough on their plate already? Do they see that application as a potential short-term opportunity? Are they used to more stringent requirements and uncomfortable with a “backwards step” in terms of process verification?
Whatever the case, the water treatment industry has a lot to offer. The International Ultraviolet Association (IUVA) has been a key resource during this time, with working groups producing a number of key education and position papers.
UV disinfection technology has become mainstream over the past decade. The impact of COVID-19 resulted in some short-term disruption to the industry, though this can be seen as a net positive. So, can we learn anything from the unique conditions of 2020, and how can we use that to accelerate innovation?
We have solutions. We have some really good solutions. They are better than we might realize. Of course, we should continue to push forward to improve. Increased efficiencies in process control, smarter deployment of sensing, increased use of technologies like UV-C LEDs, will keep raising the bar. However, we can envision wider deployment.
There is clearly a higher awareness of infection control among the global population and there is evidence that governments, corporations and individuals will invest in engineered solutions that enhance safety. Regulations can have a positive impact on the deployment of UV technology. Increased manufacturing capacity and alternate UV light-sources will lower prices, making it more accessible. Corporations that were already heading down the path on embedding UV technology into high-volume products are accelerating their innovation pipelines, as well.
This leads to communication. As widespread and as tragic as COVID-19 has been to the global human population, the fact remains that water and sanitation far outweigh it in terms of death, illness and negative economic impact. So, we need to constantly refine our message to the world of the true value of water. Because we save lives.