Ultraviolet Light Emitting Diode (UV LED)-Based Drinking Water Disinfection Systems: Issues and Challenges

Ultraviolet Light Emitting Diodes (UV LED) offer a sustainable solution for cost effective potable water disinfection systems. UV disinfection occurs owing to germicidal action of UV-C light on microorganisms. UV systems are capable of inactivating most of the water borne pathogens efficiently except some viruses. Inactivation is described by parameters maximum inactivation achieved, inactivation rate constant (cm2/mJ), and offset value (applicable for Acanthamoeba and bacterial spores). Log credits calculations of pathogen inactivation for a specific UV fluence are based on these parameters. UV LEDs are preferred over conventional mercury lamps due to non-toxicity, less power consumption, overall robustness, high efficiency, and compact form factor. Owing to all these factors, UV LEDs have potential for localized and mobile water disinfection systems. This study aimed to evaluate existing literature data and to create organized database of UV disinfection for protozoan, viruses, and bacteria in drinking water.