Photochemical Action of Far‐UVC Radiation (222 nm) in Wastewater Treatment and Indoor Air Disinfection

Abstract Ultraviolet‐ C irradiation can effectively disinfect various pathogens present in air, surfaces, and water. Various recent research studies suggest use of KrCl* (krypton‐chloride) excimer lamps to disinfect high‐risk public spaces having pathogenic bateria and viruses, as they emit Far‐UVC radiation (222 nm) with lower health risks than germicidal UVC (254 nm). The purification of water and air having pollutants and pathogens is a critical challenge in environmental protection and public health assurance. Far‐UVC excimer lamps (222 nm) have shown potential in decontaminating various organic pollutants, however, their efficacy against inorganic pollutants present in wastewater and indoor air as well as associated chemistry requires further investigations for wider acceptance. This review examines various photochemical action of Far‐UVC radiation (222 nm) in wastewater treatment and indoor air disinfection, elaborating their potential for inorganic pollutant removal in wastewater as well as challenges associated with their application in disinfection of indoor air.