A disinfecting device having an outlet (2, 42) for a flowing liquid, particularly water, and a UV irradiator (6), preferably a UV-C radiator (16) or one or more UV-C emitting light emitting diodes, and an electric power supply (7), such as a battery, turbine driven generator or a solar module, for supplying the UV irradiator with up to 25 V alternating voltage or up to 60 V direct voltage. The outlet may be constructed with a reflective interior, and a controller for regulating liquid temperature, liquid pressure and/or liquid flow rate and/or an aerator (14) for introducing air into the flowing liquid may be integrated into the device, which may be a plumbing fixture such as a water spigot.