As water treatment devices shrink and become connected, UVC LED technology enables manufacturers to include microbial disinfection capabilities in their devices.
Safe drinking water is a necessity for homes, businesses, and water equipment manufacturers across the globe. While filtering is the main method used for water treatment, disinfection of microorganisms requires a separate approach.
Ultraviolet (UV) water treatment is well-known and does not involve chemical disinfection agents. Recently, developments in ultraviolet light-emitting diodes (UVC LEDs) have made UV disinfection more flexible and convenient.
In particular, water equipment manufacturers that produce water dispensers, home water purifiers, and other specialized water treatment devices can benefit from compact UVC LED modules.
But why is it worth to consider the integration of such components? What is needed?
How Does UVC Water Disinfection Work
UV disinfection relies on short-wavelength ultraviolet light to damage genetic material in microbes. Once microorganisms get enough ultraviolet dose, their reproduction ability and infective potential is reduced.
Traditional UV water purification systems usually include low-pressure mercury lamps that radiate light with wavelength of 254 nm. However, there is a range of alternative options for UVC LEDs that include approximately 265 nm and 275 nm.
There are several factors that determine the effectiveness of UV disinfection:
- The wavelength and light output of the light source
- The ultraviolet dose that is delivered to the microorganisms
- The water flow rate and the way water passes through the UV lamp
- The clarity of the water and ultraviolet transmittance of water
- Reactor design and light distribution within the reactor
The important thing to remember about UV disinfection is that it is not the same as filtering.
While filtering removes dissolved chemicals, heavy metals, and sediments from the water, UV technology does not physically filter it. In fact, UV disinfection is recommended to be performed after filtering.
Thus, UV is often included in the water treatment system together with sediment filters, activated carbon, and reverse osmosis.
The Advantages of Compact UVC LED Technology
One of the main benefits of UVC LED technology is its compact design.
While traditional UV lamps usually imply elongated lamp structure and accompanying electrical components, UVC LEDs can be placed on a circuit board or in another optical assembly.
It provides more flexibility for water equipment manufacturers in terms of designing smaller water treatment devices.
Flexibility of Installation
UVC LED modules can be tailored to the water equipment layout.
Instead of building the water treatment device around lamp structure, manufacturers can assess LED configurations, mechanical sizes, optical configurations, and water flow patterns that match their equipment design.
Fast Turn-on/turn-off of LEDs
Another useful feature of LED lighting technology is the instant turn on/off operation.
In cases when water treatment is needed intermittently, such as in water dispensers and point-of-use purifiers, UVC LEDs can be triggered in response to water dispensing or water flow signal.
In this way, it is possible to avoid unnecessary operation of the lighting system.
However, a special attention should be paid to the control logic, so water would not bypass the treatment area without receiving the required disinfection dose.
Absence of Mercury in UV Lamp Design
Unlike traditional mercury lamps, UVC LEDs do not use mercury to generate ultraviolet light.
This feature attracts manufacturers interested in alternative technologies and material requirements.
Nevertheless, the absence of mercury is not the only characteristic that determines environmental friendliness or energy-efficiency of the system. It should be considered together with performance, component lifetime, power consumption, and maintenance.
Applications of UVC LED Modules in Water Equipment
Compact UVC LED technology is especially beneficial for devices where size, operating patterns, and flexibility of installation are important.
Point-of-use water purifiers: Compact modules can be installed in a suitably designed point-of-use water treatment device, together with other filters.
Drinking water dispensers: Flow triggered UV disinfection systems can be built to perform microbial disinfection in water dispensers.
Water treatment systems for RVs and yachts: Small size and specific optical and mechanical designs of UVC LED modules can make them suitable for water treatment in recreation vehicles and marine water systems.
Smart water appliances: UVC LED modules can be easily incorporated with sensors and controllers, providing automated control.
Specialized OEM water equipment: UVC LED modules can be integrated into specialized equipment that has specific dimensions, electrical connections, or operating requirements.
These are some of the examples of design flexibility provided by UVC LEDs. At the same time, each water treatment device needs to be designed, tested, and validated for its particular application.
Why Is Customization Important for Water Treatment Manufacturers
Each water treatment system has its own requirements.
While point-of-use water dispenser has low flow rate and small installation space, a commercial treatment unit may have other design requirements, such as reactor design, higher UV output, or other monitoring capabilities.
In this situation, customized UVC LED modules can become especially valuable for water treatment manufacturers.
Instead of choosing UV lamp component only due to the advertised output in watts, manufacturers have to analyze the complete system.
The important engineering considerations in this situation include:
1. Selection of wavelength
Depending on the application and system design, the wavelength can affect the performance of UVC LED components. Thus, the wavelength selection, such as 265 nm or 275 nm, has to be made individually.
2. Optical and reactor design
Light should be evenly distributed within the water treatment reactor. LED positioning, optical materials, reactor size, and water flow pattern affect the delivered dose.
3. Electrical compatibility
UV module has to be electrically compatible with equipment power supply, LED driver, controller, and monitoring system.
4. Thermal management
UVC LED performance and lifetime can be influenced by the temperature. Proper thermal design of LED component is therefore necessary.
5. Mechanical design
The mechanical design of the UV lamp, including PCB size, connectors, housing, mounting arrangement, and water connections, can help manufacturers to integrate UVC technology in existing or new water equipment.
Ultraviolet components suppliers can help to take care of these requirements. For example, YOYO-UV offers custom UVC LED solutions for water treatment equipment including system and module integration for OEM and ODM projects.
The purpose of customization is not simply to make UVC LED module smaller, but to develop the configuration that works properly within the water treatment system.
Proper System Testing Cannot Be Overestimated
Despite the advantage that compact UVC LED technology provides, the successful water treatment is not guaranteed just by the installation of the UVC LED components.
Ultraviolet dose delivery has to be assessed under the actual operating conditions.
Water with high turbidity or low UV transmittance can affect the performance of UVC LED technology because suspended sediments and dissolved particles absorb or scatter the UV light.
Excessive flow rate can reduce the exposure time and result in insufficient dose delivery.
Water treatment equipment manufacturer should assess:
- The maximum flow rate during the water treatment
- Water quality and UV transmittance of water
- Minimum UV output at operating conditions
- Temperature influence and aging of LEDs
- Sensor functionality and fault detection
- Performance under operating conditions
In the case of drinking water applications, there are specific standards that should be taken into account.
In the United States, NSF/ANSI 55 defines requirements for ultraviolet microbiological water treatment systems and classifies them into Class A and Class B systems.
Specified in advertisements of the UVC LED components, the characteristics are not necessarily mean the certification of the whole water treatment system.
Furthermore, manufacturers should make sure that UVC radiation is enclosed and the user would not be accidentally exposed to the UV light during the water treatment.
The Future of UV Water Treatment Is in System Design
Compact UVC LEDs expand the design options available to water treatment equipment manufacturers.
Small size, flexible installation, and electronic control capability make them especially suitable for point-of-use devices, smart water appliances, and OEM devices.
Still, conventional UV technologies remain effective and even advantageous for some applications that require high flow rates or continuous water flow.
The future of water treatment is therefore not likely to lie in one universal light source, but in the choice of technology based on water quality, operating requirements, water equipment design, and UV disinfection performance.
For the companies that develop the next generation of water purification devices, the most important opportunity is not the usage of the newest UV components. It is the combination of UV technology, proper engineering, and UV disinfection system validation.