title: Development of a new water sterilization device with a 365 nm UV-LED.
abstract: Ultraviolet (UV) irradiation is an effective disinfection method. In sterilization equipment, a low-pressure mercury lamp emitting an effective germicidal UVC (254 nm) is used as the light source. However, the lamp, which contains mercury, must be disposed of at the end of its lifetime or following damage due to physical shock or vibration. We investigated the suitability of an ultraviolet light-emitting diode at an output wavelength of 365 nm (UVA-LED) as a sterilization device, comparing with the other wavelength irradiation such as 254 nm (a low-pressure mercury lam) and 405 nm (LED). We used a commercially available UVA-LED that emitted light at the shortest wavelength and at the highest output energy. The new sterilization system using the UVA-LED was able to inactivate bacteria, such as Escherichia coli DH5 alpha, Enteropathogenic E. coli, Vibrio parahaemolyticus, Staphylococcus aureus, and Salmonella enterica serovar Enteritidis. The inactivations of the bacteria were dependent on the accumulation of UVA irradiation. Taking advantage of the safety and compact size of LED devices, we expect that the UVA-LED sterilization device can be developed as a new type of water sterilization device.
authors.affiliation: Department of Electrical and Electronic Engineering, Institute of Socio Techno Sciences, The University of Tokushima, Tokushima City, Tokushima 770-8503, Japan.
authors.forename: Mirei
authors.initials: M
authors.lastname: Mori
authors.forename: Akiko
authors.initials: A
authors.lastname: Hamamoto
authors.forename: Akira
authors.initials: A
authors.lastname: Takahashi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nakano
authors.forename: Noriko
authors.initials: N
authors.lastname: Wakikawa
authors.forename: Satoko
authors.initials: S
authors.lastname: Tachibana
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Ikehara
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakaya
authors.forename: Masatake
authors.initials: M
authors.lastname: Akutagawa
authors.forename: Yohsuke
authors.initials: Y
authors.lastname: Kinouchi
mesh_terms: D004581:Electronics / Q000295:instrumentation; D004867:Equipment Design; D008027:Light; D010782:Photolysis; D013242:Sterilization / Q000295:instrumentation* / Q000379:methods; D014466:Ultraviolet Rays; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods