Hi all…two papers on full-scale/demonstration-scale evaluations of UV-LED for disinfection have been recently published (below). Both tested the world’s first commercial UVC LED water disinfection reactor (the PearlAqua by Aquisense) and successfully demonstrated “proof-of-concept for the application of UVC LEDs for municipal water treatment.” UV LED technology continues to be a promising alternative to UV mercury lamp-based systems.



Application of Ultraviolet Light-Emitting Diodes (UV-LED) to Full-Scale Drinking-Water Disinfection

Peter Jarvis, Olivier Autin, Emma H. Goslan and Francis Hassard

Water 2019, 11(9), 1894; doi:10.3390/w11091894 https://www.mdpi.com/2073-4441/11/9/1894


Abstract “Ultraviolet light-emitting diodes (UV-LEDs) have recently emerged as a viable technology for water disinfection. However, the performance of the technology in full-scale drinking-water treatment systems remains poorly characterised. Furthermore, current UV disinfection standards and protocols have been developed specifically for conventional mercury UV systems and so do not necessarily provide an accurate indication of UV-LED disinfection performance. Hence, this study aimed to test the hypothesis that a full-scale UV-LED reactor can match the Cryptosporidium inactivation efficiency of conventional mercury UV reactors. Male-specific bacteriophage (MS2) was used as the Cryptosporidium spp. Surrogate microorganism. The time-based inactivation efficiency of the full-scale reactor was firstly compared to that of a bench-scale (batch-type) UV-LED reactor. This was then related to mercury UV reactors by comparing the fluence-based efficiency of the bench-scale reactor to the USEPA 90% prediction interval range of expected MS2 inactivation using mercury UV lamps. The results showed that the full-scale UV-LED reactor was at least as effective as conventional mercury UV reactors at the water quality and drive-current conditions considered. Nevertheless, comparisons between the bench- and full-scale UV-LED reactors indicated that improvements in the hydraulic flow profile and power output of the full-scale reactor could help to further improve the efficiency of UV-LED reactors for municipal drinking water disinfection. This represents the world’s first full-scale UV-LED reactor that can be applied at municipal water treatment works for disinfection of pathogenic microorganisms from drinking water.”


UV LED Water Disinfection: Validation and Small System Demonstration Study

Natalie M. Hull, William H. Herold, Karl G. Linden

AWWA Water Science Volume1, Issue4 July/August 2019 e114 https://awwa.onlinelibrary.wiley.com/doi/abs/10.1002/aws2.1148


“Disinfection by ultraviolet (UV) light via non‐mercury light‐emitting diodes (LEDs) may be a sustainable solution for drinking water disinfection in small systems. The world’s first commercial UVC LED water disinfection reactor (the PearlAqua by Aquisense) was studied over a year‐long demonstration test, and performance was compared side by side with an existing chlorination system at a small water treatment plant in Colorado. The UVC LED disinfection system was validated using MS2 bacteriophage inactivation over a range of flow rates and water UV transmittances. The reactor was also challenge‐tested with MS2 periodically during the year‐long demonstration. During lab tests and the field study in challenging conditions without any maintenance, the reactor demonstrated viral and bacterial disinfection efficacy and resilience equivalent to the chlorination system, providing proof of concept for application of UVC LEDs for municipal water treatment.”