UV-C lightUV sterilizer Serie PuroIn the PURO sterilizers, the treated water is exposed to the UV light emitted by germicidal low pressure mercury vapor lamps. These lamps emit a concentrated beam of UV light at 254 nm that, at appropriate doses, eliminates bacterial contamination in the liquid. In fact, the UV-C light emitted by the lamps penetrates the bacterial cell wall, irreversibly damages their genetic heritage in the DNA, and prevents their reproduction.