How can we use UV technology to reduce the concentration of TOCs in systems

To achieve ultrapure water for applications that require it, such as those in the pharmaceutical, semiconductor and microelectronic industry, the correct level of disinfection is required.
Posted: Thursday, 3 October 2019

There are a few effective methods currently available, one of those is the use of UV technology. The reason we need to disinfect water thoroughly and efficiently is to ensure the safety of the population who will be using the end product, and TOC’s (Total Organic Carbons) are one of the threats to the purity of water. TOC’s are organic materials, usually a by-product of bacterial growth or vegetation decay by which the levels of this contamination are measured by the amount of carbon in these organic compounds. These levels can vary greatly depending on the type of water that is being treated, so it is vital to ensure TOC concentrations are monitored and analysed consistently to achieve the correct level of reductions.

UV technology can reduce the TOC levels in water by using the energy from a specific ultraviolet wavelength to dissociate the water molecules and break their bonds to create free radicals, or hydroxyls as they can also be known. Once this happens and the atoms are free from bonds, they will become highly reactive and will search out other atoms to create new, naturally occurring bonds. They will actively couple with the TOC carbon atoms to create new molecules. When hydroxyls combine with the TOC carbon atoms, they form carbon dioxide and water molecules. Once this process is complete, the total oxidizable carbons are destroyed.

To be able to break the bonds of the molecules, the dose of UV needs to be fairly high. Although a dose of 185nm would be enough to achieve this process, this dose has a low level of water transmittance, which means it could be less effective, especially in large bodies of water. A higher dose of around 254nm is recommended to ensure the treatment is effective enough and, consequently, this dose also provides a level of decontamination with disinfection as an added bonus.

Alpha-Purify offers UV lamps that generate the correct dose of UV for TOC reduction.

Please contact our Head of Global Sales, Berenika Bond, for a competitive quote by emailing, berenika.bond@alpha-purify.com or use the Contact Us page