As UV LEDs continue to be incorporated into water systems at household and municipal levels, researchers, manufacturers and utility operators increasingly are considering taking advantage of the synergistic effect of UV-A and UV-C irradiation in the photoinactivation of some bacteria by adding LEDs that emit in the UV-A range. Such a change could not only reduce costs but also lead to improved disinfection. There has been a justifiable need to understand the basis of this synergistic effect when combining the two wavelength ranges with different inactivation mechanisms. The authors’ recent paper in Water Research, from the doctoral work of Dr. Sandra Probst-Rüd under Dr. Martin Ackermann and Dr. Kris McNeill at ETH-Zurich, with the support of Dr. Sara Beck, Dr. Paul Nyangaresi and Adefolawe Adeyeye at the University of British Columbia, answered this question. Read More