Ultraviolet (UV) light is used as a method to inactivate microorganisms by interrupting nucleic acids and disrupting their DNA, effectively preventing replication. Ultraviolet light that is used in-line in laboratory water purification systems are low pressure mercury lamps.
How does it work?
UV radiation disrupts DNA and RNA polymerase at low doses while breaking down large organic molecules into smaller ionized components. These components are then removed downstream by high purity ion exchange resin beds. Prior removal of organic ions optimizes the effectiveness of this technology in water purification. Ultraviolet is also used in photolysis to remove chlorine and chloramine species from the water.
Treatment of water with UV-C light is used to photo-oxidise organic impurities and/or inactivate micro-organisms. Photo-oxidation of organic impurities results in polar or charged species that can be subsequently be removed by ion-exchange processes. Typically the UV lamp forms part of a 'polishing' treatment loop including ion-exchange, through which water is repeatedly circulated to maintain quality. Water with Total Organic Carbon (TOC) of <5 ppbC and bacteria at <1 CFU/ml can be achieved in ELGA products that use this approach.