Knowledge Base

eBook: Three Things Water Purification Designers Need to Know About UVC LEDs

eBook: Three Things Water Purification Designers Need to Know About UVC LEDs

KLARAN UNIVERSITY / KNOWLEDGE BASE

Klaran University / Knowledge base

Three Things Water Purification Designers Need to Know About UVC LEDs

Water purification companies are under pressure to add new features that help their products stand-out. UVC LED technology can address the design challenges engineers face in these situations, such as making products more compact and low-maintenance while providing a beautiful and appealing aesthetic. Download this free eBook to learn: Why should you incorporate disinfection in your products? How do UVC LED-based solutions make it easier to design products that meet consumers' growing water hygiene preferences? How does UVC LED technology compare to other UVC disinfection solutions (e.g. mercury lamps)?

Get the Ebook

- BACK TO ALL ARTICLES -

RELATED RESOURCES

10 Common Places to Spot Bacteria in Water Infrastructure

UV Lamps vs UVC LEDs: Which is Best for Water Disinfection?

Water, eBooks

Read more: eBook: Three Things Water Purification Designers Need to Know About UVC LEDs

  • Hits: 80

10 Common Places to Spot Bacteria in Water Infrastructure

10 Common Places to Spot Bacteria in Water Infrastructure

KLARAN UNIVERSITY / KNOWLEDGE BASE

Klaran University / Knowledge base

10 Common Places to Spot Bacteria in Water Infrastructure

Municipalities and utilities use aggressive strategies to help purify our drinking water, yet microorganisms are constantly reproducing beyond the treatment plant. While this illustrates the myriad places where water hygiene risks can occur in businesses and homes, it also highlights the many places where UVC disinfection can be used for helping to destroy- and stop the spread of- bacteria in water. In this post, you’ll learn where bacteria can come from, how they reproduce in water, and where they’re most likely to come into contact with consumers.

1. From the Water Treatment Plant Technically speaking, disinfection methods at water treatment plants are not sterile, which means that single microbes can make their way from the treatment plant directly into the drinking water stream. Far too often, this is the story of “the one that got away” (and got in to our drinking water supply).

2. Leaks in Pipes It’s not uncommon for small leaks to be present in our progressively aging, underground water infrastructure. The problem with these leaks is that they let pathogens from soil or waste enter the water that we consume.

3. Bacteria Colonies Growing on the Pipes As microorganisms enter the water system, they attach to pipe walls throughout the system and begin forming a biofilm. This biofilm protects microorganisms and allows them to reproduce inside of our water infrastructure.

4. Dead Ends in the Infrastructure Capped-off sections of pipes in our water infrastructure are referred to as “dead ends.” Since there is no flow through dead ends, the water stagnates and becomes a safe harbor for biofilm formation.

5. Newly Formed Colonies in the Pipes of a House or Building As water enters buildings and homes, microorganisms that have broken away from biofilm spread and establish new growth inside of our plumbing in the same way they were able to grow in the larger, municipal infrastructure.

6. Water Heaters Water heaters typically maintain water temperatures high enough to limit continued bacterial growth, but maintenance issues that lead to scaling or insufficient heating can result in tank fouling and temperature reductions. Unfortunately, these are the perfect conditions for microorganisms to flourish.

7. Beverage Equipment and Water-Dispensing Appliances For many food and beverage service operations, beverage equipment (e.g. coffee machines, soda dispensers, etc.) help provide a steady stream of revenue to the business. As a result, it’s critical to have precautionary measures and preventative maintenance in-place to limit equipment down-time. Scale filters and frequent cleaning can act as a band-aid solution, but microorganisms and biofilm growth stemming from source water or dispensing points circumvent these efforts by passing through filters and growing almost anywhere water is present. Not only does this potentially damage equipment, this contamination can also lead to illnesses for customers and employees alike.

8. Sinks and Taps Sinks and taps are one of our most common touchpoints with consumable water- providing water that we use for everything from cleaning to drinking. While some taps primarily used for cleaning, watering, or rinsing don’t necessarily demand any protection against microorganisms, if the water from sinks and taps is used for drinking or preparing food or beverages, then it’s important to understand where contaminants from municipal water may pose a risk.

9. Shows and Bathtub Faucets Water that is used for bathing is mainly critiqued for comfort rather than for drinking water safety. Nevertheless, it can still pose substantial risks when bacteria are present. Showers are one of the most common fixtures in buildings that can cause water to aerosolize, making microorganisms in water (e.g. legionella) a potential airborne risk.

10. Water Coolers and Water Lines Water coolers- using bottled water or connected to a water line- are notorious hotspots for biofilm growth. Biofilm and mold growth- whether it’s from the municipal water source or from environmental exposure that occurs when consumers replace water cooler jugs- can form rapidly in internal components of the water cooler or water line. Although sanitation procedures are used as a minimum precaution for preventing biofilm and mold growth, providing complete water hygiene from these dispensers should incorporate an on-demand disinfection method (e.g. a UVC LED-based water disinfection system) to ensure that the dispensed water meets consumers’ hygiene expectations. While it’s true that microorganisms can be anywhere in our water, it’s not an immediate need to consider expensive whole house point-of-entry disinfection systems. Water serves a purpose at each point in a building and can be protected in an ad hoc manner at each point with desirable point-of-use water disinfection solutions. For more information about choosing the right solution for microbial protection at your flow rate and usage needs, check out our guide on UVC LEDs vs. UV lamps.

1. From the Water Treatment Plant Technically speaking, disinfection methods at water treatment plants are not sterile, which means that single microbes can make their way from the treatment plant directly into the drinking water stream. Far too often, this is the story of “the one that got away” (and got in to our drinking water supply).

2. Leaks in Pipes It’s not uncommon for small leaks to be present in our progressively aging, underground water infrastructure. The problem with these leaks is that they let pathogens from soil or waste enter the water that we consume.

3. Bacteria Colonies Growing on the Pipes As microorganisms enter the water system, they attach to pipe walls throughout the system and begin forming a biofilm. This biofilm protects microorganisms and allows them to reproduce inside of our water infrastructure.

4. Dead Ends in the Infrastructure Capped-off sections of pipes in our water infrastructure are referred to as “dead ends.” Since there is no flow through dead ends, the water stagnates and becomes a safe harbor for biofilm formation.

5. Newly Formed Colonies in the Pipes of a House or Building As water enters buildings and homes, microorganisms that have broken away from biofilm spread and establish new growth inside of our plumbing in the same way they were able to grow in the larger, municipal infrastructure.

6. Water Heaters Water heaters typically maintain water temperatures high enough to limit continued bacterial growth, but maintenance issues that lead to scaling or insufficient heating can result in tank fouling and temperature reductions. Unfortunately, these are the perfect conditions for microorganisms to flourish.

7. Beverage Equipment and Water-Dispensing Appliances For many food and beverage service operations, beverage equipment (e.g. coffee machines, soda dispensers, etc.) help provide a steady stream of revenue to the business. As a result, it’s critical to have precautionary measures and preventative maintenance in-place to limit equipment down-time. Scale filters and frequent cleaning can act as a band-aid solution, but microorganisms and biofilm growth stemming from source water or dispensing points circumvent these efforts by passing through filters and growing almost anywhere water is present. Not only does this potentially damage equipment, this contamination can also lead to illnesses for customers and employees alike.

8. Sinks and Taps Sinks and taps are one of our most common touchpoints with consumable water- providing water that we use for everything from cleaning to drinking. While some taps primarily used for cleaning, watering, or rinsing don’t necessarily demand any protection against microorganisms, if the water from sinks and taps is used for drinking or preparing food or beverages, then it’s important to understand where contaminants from municipal water may pose a risk.

9. Showers and Bathtub Faucets Water that is used for bathing is mainly critiqued for comfort rather than for drinking water safety. Nevertheless, it can still pose substantial risks when bacteria are present. Showers are one of the most common fixtures in buildings that can cause water to aerosolize, making microorganisms in water (e.g. legionella) a potential airborne risk.

10. Water Coolers and Water Lines Water coolers- using bottled water or connected to a water line- are notorious hotspots for biofilm growth. Biofilm and mold growth- whether it’s from the municipal water source or from environmental exposure that occurs when consumers replace water cooler jugs- can form rapidly in internal components of the water cooler or water line. Although sanitation procedures are used as a minimum precaution for preventing biofilm and mold growth, providing complete water hygiene from these dispensers should incorporate an on-demand disinfection method (e.g. a UVC LED-based water disinfection system) to ensure that the dispensed water meets consumers’ hygiene expectations.

While it’s true that microorganisms can be anywhere in our water, it’s not an immediate need to consider expensive whole house point-of-entry disinfection systems. Water serves a purpose at each point in a building and can be protected in an ad hoc manner at each point with desirable point-of-use water disinfection solutions. For more information about choosing the right solution for microbial protection at your flow rate and usage needs, check out our guide on UVC LEDs vs. UV lamps.

- BACK TO ALL ARTICLES -

RELATED RESOURCES

Three Things Water Purification Designers Need to Know About UVC LEDs

Microbial Performance of the Klaran AKR Reactor

Water, Articles

Read more: 10 Common Places to Spot Bacteria in Water Infrastructure

  • Hits: 1302

How UVC Disinfection Can Help Protect Food and Beverage Service Operations Before and After Boil-Water Advisories

Boil-Water Advisory
Klaran University / Knowledge base

How UVC Disinfection Can Help Protect Food and Beverage Service Operations Before and After Boil-Water Advisories


James Peterson

By James Peterson

Product Manager

Boil-water advisories are an instant headache for any commercial food service operation. The effect on beverage service can become the leading pain point for many operations long after the boil-water period. In these situations, UVC disinfection systems can help food service operations deliver microbially safe water and be assured that their service equipment is protected from damage or maintenance due to biofilm and microorganism growth.

During an active boil-water advisory, it is critical to follow all local health department and water utility guidelines regarding water use. Further, it is critical to have additional plans in place before and after notices as microbial contaminant risks can be expected outside of the advisory period.

Protection Before the Advisory

A boil-water advisory is posted when a known incident or microorganism has been identified, and then a food and beverage service provider must become aware of the notice to act properly. While the gap between an advisory being posted and a company’s response may range from a few minutes to a few hours, the situation within your water infrastructure started before the notice was announced. This means that microbial contamination may have been present in your water for days or weeks before the utility companies were able to identify the issue and notify the public. However, health departments hold food and beverage service providers responsible for protecting their customers from contaminated drinking water at all times.

Since there are numerous places where bacteria can be found in water infrastructure, it's important that businesses cover their bases.

Constant protection against this unknown period of microbial risk can seem daunting and expensive but it does not have to be. Food and beverage service providers can use point-of-use purification solutions instead of more costly point-of-entry purification systems. Point-of-use components with verified microbial reduction claims can be integrated directly before beverage equipment or incorporated by the OEM. Systems using UVC LEDs typically offer tens of thousands of liters of treatment over a flexible lifetime and, unlike UV lamp systems, do not warm the water (warming water can lead to microbial growth).

Protection After the Advisory

Once the advisory is lifted, the real work begins for food and beverage service providers. In accordance with local health department and equipment manufacturer guidelines, companies must flush all water and beverage lines, clean and sanitize equipment, and empty and replenish storage tanks.

After all of that work, however, stagnant pipes within our municipal and building water infrastructure hold plentiful opportunities for dangerous organisms to harbor and multiply, potentially finding their way back into a food and beverage establishment’s water service. This can result in unsafe water being served to customers, improper equipment operation, or equipment damage from unexpected biofilm growth.

For establishments using filtration cartridges with verified microbial reduction claims, those, along with any other filtration-based purification components would need to be replaced after a boil-water advisory. The unknown levels of contaminants during an advisory can rapidly degrade high capacity purification cartridges, which can lead to clogging or breaches that allow contaminated water to pass through the cartridge unnoticed.

Fortunately, point-of-use UVC disinfection systems are not susceptible to such replacement requirements after boil-water advisories because they are not prone to clogging or breaches. Point-of-use UVC LED purifiers provide the assurances of safe service and protected equipment. Moreover, in the absence of boil-water advisories, UVC LED purifiers offer reliable purification without affecting temperature, taste, or smell of the water.

The Klaran AKR reactor and Klaran WD UVC LEDs, for example, are available for water professionals or equipment OEMs to deliver these solutions to their customers now, so food and beverage service providers can trust their water and get on with their business without additional maintenance requirements.


Klaran University



RELATED RESOURCES

Guide to UVC LEDs for disinfection in healthcare

Press Release

Crystal IS Klaran UVC LED for Water Disinfection Demonstrates Legionella Performance

Read more


UV Lamps vs. UVC LEDs: Which is Best for Your Water Disinfection Needs?

Webinar

UV Lamps vs. UVC LEDs: Which is Best for Your Water Disinfection Needs?

Read more

Water, Articles

Read more: How UVC Disinfection Can Help Protect Food and Beverage Service Operations Before and After...

  • Hits: 444

How a UVC LED Works

How a UVC LED works

KLARAN UNIVERSITY / KNOWLEDGE BASE

Klaran University / Knowledge base

How a UVC LED Works

A common question companies ask when exploring UVC LEDs for disinfection applications relates to how UVC LEDs actually work. In this article, we provide an explanation of how this technology operates.

General Priciples of LEDs A light-emitting diode (LED) is a semiconductor device that emits light when a current is passed through it. While very pure, defect-free semiconductors (so-called, intrinsic semiconductors) generally conduct electricity very poorly, dopants can be introduced into the semiconductor which will make it either conduct with negatively charged electrons (n-type semiconductor) or with positively charged holes (p-type semiconductor). An LED consists of a p-n junction where a p-type semiconductor is put on top of an n-type semiconductor. When a forward bias (or voltage) is applied, electrons in the n-type region are pushed toward the p-type region and, likewise, holes in the p-type material are pushed in the opposite direction (since they are positively charged) toward the n-type material. At the junction between the p-type and n-type materials, the electrons and holes will recombine and each recombination event will produce a quantum of energy that is an intrinsic property of the semiconductor where the recombination occurs. Side note: electrons are generated in the conduction band of the semiconductor and holes are generated in the valence band. The difference in energy between the conduction band and the valence band is called the bandgap energy and is determined by the bonding characteristics of the semiconductor.

Radiative recombination results in the production of a single photon of light with an energy and wavelength (the two are related to each other by Planck’s equation) determined by the bandgap of the material used in the active region of the device. Non-radiative recombination can also occur where the quantum of energy released by the electron and hole recombination produces heat rather than photons of light. These non-radiative recombination events (in direct bandgap semiconductors) involve mid-gap electronic states caused by defects. Since we want our LEDs to emit light, not heat, we want to increase the percentage of radiative recombination compared to non-radiative recombination. One way to do this is to introduce carrier-confining layers and quantum wells in the active region of the diode to try to increase the concentration of electrons and hole which are undergoing recombination under the right conditions. However, another key parameter is reducing the concentration of defects which cause non-radiative recombination in the active region of the device. That is why the dislocation density plays such an important role in optoelectronics since they are a primary source of non-radiative recombination centers. Dislocations can be caused by many things but achieving a low density will nearly always require the n-type and p-type layers used to make the active region of the LED are grown on a lattice-matched substrate. Otherwise, dislocations will be introduced as a way to accommodate the difference in crystal-lattice structure. Therefore, maximizing LED efficiency means increasing the radiative recombination rate relative to the non-radiative recombination rate by minimizing dislocation densities.

UVC LEDs Ultraviolet (UV) LEDs have applications in the field of water treatment, optical data storage, communications, biological agent detection and polymer curing. The UVC region of the UV spectral range refers to wavelengths between 100 nm to 280 nm. In the case of disinfection, the optimum wavelength is in the region of 260 nm to 270 nm, with germicidal efficacy falling exponentially with longer wavelengths. UVC LEDs offer considerable advantages over the traditionally used mercury lamps, notably they contain no hazardous material, can be switched on/off instantaneously and without cycling limitation, have lower heat consumption, directed heat extraction, and are more durable. In the case of UVC LEDs, to achieve short wavelength emission (260 nm to 270 nm for disinfection), a higher aluminum mole fraction is required, which makes the growth and doping of the material difficult. Traditionally, bulk lattice-matched substrates for the III-nitrides was not readily available, so sapphire was the most commonly used substrate. Sapphire has a large lattice mismatch with high Al-content AlGaN structure of UVC LEDs, which leads to an increase in non-radiative recombination (defects). This effect seems to get worse at higher Al concentration so that sapphire-based UVC LEDs tend to drop in power at wavelengths shorter than 280 nm faster than AlN-based UVC LEDs while the difference in the two technologies seems less significant in the UVB range and at longer wavelengths where the lattice-mismatch with AlN is larger because higher concentrations of Ga are required. Pseudomorphic growth on native AlN substrates (that is where the larger lattice parameter of intrinsic AlGaN is accommodated by compressing elastically it to fit on the AlN without introducing defects) results in atomically flat, low defect layers, with peak power at 265 nm, corresponding to both the maximum germicidal absorption while also reducing the effects of uncertainty due to spectral-dependent absorption strength. Crystal IS has developed high-quality bulk lattice-match AlN substrates which allows for higher internal efficiency and lower internal absorption. These substrates, used in the manufacture of Klaran UVC LEDs and products, provides higher quality, more powerful LEDs at wavelengths in the germicidal range.

- BACK TO ALL ARTICLES -

RELATED RESOURCES

A Guide to UVC LEDs for Disinfection in Healthcare

What is Spectral Sensitivity? Explaining Differences in Microbe Sensitivity to UV Wavelength

Air, Surface, Water, Articles

Read more: How a UVC LED Works

  • Hits: 312

The Role of UVC LED Reliability in Product Design

Spectral Sensitivity

KLARAN UNIVERSITY / KNOWLEDGE BASE

Klaran University / Knowledge base

The Role of UVC LED Reliability in Product Design

LEDs are enabling UV disinfection to be integrated in ways never before possible—from water disinfection right at the point-of-dispense to portable point-of-care medical devices that reduce HAIs. For these applications, it’s not the first glass of water or the first patient that is the primary concern - it’s the last. To ensure disinfection performance in your application is as good at the end of the product's life as it is out of the box, you need to understand the relationship between UVC LED lifetime and reliability. Lifetime is a variable, not a specification. We talk about the approach to defining required lifetime for both point-of-use water and healthcare applications in other articles on our website. When selecting a UVC LED to meet application requirements, understanding role of device reliability and its relationship to lifetime is an important distinction to understand.

What do we mean by reliability? When we’re talking about product reliability, we are referring to the percentage of the LED population operating outside specifications. For a given forward current and operating temperature, there will be a natural statistical distribution of light degradation (or lifetime). The percentage of devices in a population which exhibit light output below a specified L value is known as the B value. Figure 1 (below) provides different LEDs behaviors based on B values of a population. The blue line shows that at 500 hours, under the specific operating conditions 50 percent of a sample population (the average) will emit 45 mW while 50 percent of the sample population will emit something less than 45 mW.

Figure 1: UVC output for a population of devices operated at a drive current of 700 mA with an ambient temperature of 35°C. The graph shows the population data for reliability values of B50 and B10.

The red line in Figure 1 shows data for B10 of this group of devices. The B10 line shows that at 500 hours only 10 percent of devices emit less than 36 mW of their initial output—which is the L60B10 value.

Why should you care about reliability? Engineers need to consider end of life performance when designing disinfection applications. As stated before—it’s the safety of the last glass of water or the last patient that is the most important. To determine this, designers need to first understand the UVC power required for that last dose, and then calculate the cumulative on time for their product lifetime. Because of the instant on/off nature of LEDs, it’s this cumulative on time that is the required device lifetime. Generically, designers are typically either designing to the lowest cost solution—like in consumer goods, or the highest level of disinfection confidence—like in healthcare. Lowest cost solutions often require the fewest number of LEDs possible while there is no room for error in critical infection prevention equipment. If half the LEDs fail then you risk delivering less than the required disinfection dose so, understanding how 50 percent (B50) of an LED population will behave is not enough. Design engineers can increase their end product quality by looking at lifetime performance at lower B values, like the red line in Figure 1. By understanding this data, the total UVC power required at the end of life, and the cumulative on time in an application, design engineers can ensure disinfection performance that offers the highest level of confidence for the lowest cost in their products.

- BACK TO ALL ARTICLES -

RELATED RESOURCES

A Guide to UVC LEDs for Disinfection in Healthcare

FAQs for Surface Disinfection

Air, Surface, Water, Articles

Read more: The Role of UVC LED Reliability in Product Design

  • Hits: 354