International Ultraviolet Association, London, Ontario, Canada.
Department of Civil, Environmental, and Geodetic Engineering, The Ohio State University, Columbus, Ohio, USA.
Water Environ Res. 2023 Nov;95(11):e10947. doi: 10.1002/wer.10947.
The International Ultraviolet Association (IUVA) Task Force was formed to develop guidelines regarding testing and reporting on performance of UV LED water disinfection systems. The goal was to provide clarity in a guidance document on measuring system performance across the global UV LED water disinfection system market. A review of current performance measurement protocols for mercury lamp based systems shows that the common elements of UV LED system performance measurement protocols should be as follows: specified standard for the amount of pathogen reduction required, the requirement that the validation testing be conducted by a competent facility, and that the system be continually monitored by UV sensors while in use to verify system performance unless pathogen reduction is not claimed. UV LEDs have selectable peak wavelengths, as opposed to mercury lamps that have fixed emission wavelength values. As a result of this difference, the following changes to protocols used to test mercury lamp systems are recommended. First, the use of disinfection benchmarks other than 254 nm dose, such as direct inactivation values, dose benchmarks referenced to 254 nm, and/or dose benchmarks at the UV LED emission wavelength that give the same inactivation as the original 254 nm UV dose benchmark. Second, the use of 254 nm UV water transmittance values as a placeholder, rather than an assumed correct value, for systems under test with LED wavelengths >250 nm and water transmittance values ≥87%. More research is needed for lower wavelengths and UVTs. Third, the recommendation that germicidal response UV sensors be used in UV LED based systems to ensure that the validated disinfection is delivered. Finally, additional LED-specific considerations were also noted. UV LEDs are also instant-on devices, making them ideal light sources for systems operated intermittently. Performance testing of systems operated intermittently should include a test to insure that pathogens do not migrate past the UV LEDs while the LEDs are off. UV LED devices have recognized protocols for determining the lifetime of the devices, as well as for measuring other device properties. Caution should be exercised in using these lifetime values for devices in UV disinfection systems, since the thermal environment of the devices may be different for protocol testing and disinfection system operation. PRACTITIONER POINTS: Validation of UVC LED fluid disinfection is necessary for point of use, point of entry, and municipal applications. The emission spectrum properties, considerations and measurements for output over lifetime, and unique system design considerations of UVC LEDs as light sources are factors that must be considered when evaluating fluid disinfection performance. The instant-on operation, system geometry, validation benchmarks, system sensing, water transmittance, and fouling must also be considered for UVC LED devices when evaluating fluid disinfection performance.
国际紫外线协会（IUVA）工作组的成立旨在制定有关 UV LED 水消毒系统测试和报告性能的指南。目标是在全球 UV LED 水消毒系统市场上提供一份关于测量系统性能的指导文件，以明确说明。对基于汞灯的系统当前性能测量协议的审查表明，UV LED 系统性能测量协议的共同要素应如下：规定所需病原体减少量的标准、要求验证测试由合格的设施进行，以及在使用过程中通过 UV 传感器持续监测系统以验证系统性能，除非不声称病原体减少。UV LED 具有可选择的峰值波长，而汞灯则具有固定的发射波长值。由于这种差异，建议对用于测试汞灯系统的协议进行以下更改。首先，使用除 254nm 剂量以外的消毒基准，例如直接失活值、参考 254nm 的剂量基准和/或在与原始 254nm UV 剂量基准产生相同失活的 UV LED 发射波长处的剂量基准。其次，对于 LED 波长>250nm 且水透射率值≥87%的测试系统，使用 254nm UV 水透射率值作为占位符，而不是假定的正确值。第三，建议在基于 UV LED 的系统中使用杀菌响应 UV 传感器，以确保提供经过验证的消毒。最后，还注意到了其他与 LED 相关的考虑因素。UV LED 也是即时开启的设备，因此非常适合间歇性运行的系统。间歇性运行系统的性能测试应包括一项测试，以确保在 LED 关闭时病原体不会迁移到 UV LED 之外。UV LED 设备具有确定设备寿命以及测量其他设备特性的公认协议。在将这些寿命值用于 UV 消毒系统中的设备时应谨慎，因为设备的热环境可能与协议测试和消毒系统操作不同。从业者要点：UVC LED 流体消毒的验证对于就地使用、入口点和市政应用是必要的。UVC LED 作为光源的发射光谱特性、考虑因素和使用寿命期间的输出测量以及独特的系统设计考虑因素是评估流体消毒性能时必须考虑的因素。在评估流体消毒性能时，还必须考虑即时开启操作、系统几何形状、验证基准、系统感应、水透射率和结垢等因素，也必须考虑 UVC LED 设备。
