View Full Version : UV sterilizer producing co2?

11-09-2010, 10:38 PM
Was reading some articles about UV sterilization- this particular article doesn't have anything to do with aquariums, but it did mention something that caught my eye- A "high end" (AKA- one that has a smaller distance between quartz sleeve and the UV bulbs) UV sterilizer will oxidize organic carbon compounds into "less harmful elements"... one of them mentioned is co2. I know the amount produced is probably trivial- but it was interesting... here's an excerpt:

Organic compounds can be removed by treatment of the water with activate carbon. UV-purification systems can, depending on the type of system, sterilize water by killing microorganisms such as bacteria and viruses (UV sterilizers) or even decrease the Total Organic Carbon content (TOC) by oxidizing organic carbon compounds into less harmful compounds. UV radiation treatment devices usually employ a low pressure mercury lamp as a source of UV-radiation. The lamps create UV light of a range of wave lengths. Lamps with a regular quartz sleeve will let UV light of a wavelength of 254nm pass. This light is absorbed optimally by DNA in microorganisms and kills them this way. UV lamps with an ultrapure quartz sleeve will let UV light of two wave lengths pass: 254nm for sterilization purposes and additionally higher energetically UV light of 185nm wavelength. This light can oxidize organic compounds and thus reduce the TOC to values of under 5ppb. Oxidizing of organic compounds, however, can only reduce a certain amount of TOC, and therefore should be used as a final polishing step after ultrafiltration to achieve the lowest TOC counts. The CO2 that it produces reduces resistivity of the water and an UV-oxidizer cannot remove any ions, so that most water purification systems employ a deionizing step after the UV-oxidization-treatment.

and a link: