Pharmaceutical, healthcare products, and research labs require production facilities of the utmost quality. Water used for these industries must be free of pathogens, and chemicals such as chlorine and ozone. Ultraviolet (UV) systems help provide water to the highest possible standards.
Ultraviolet Applications for the Life Sciences Industry
- TOC Reduction
- Microbial Disinfection
- Ozone Destruct
- Chlorine/Chloramine Destruct
The USP 31 regulations require an upper limit of 500 ppb for TOC (Total Oxidizable Carbon) for both USP Purified Water, as well as, water for injection. The more powerful UV wavelength of 185nm, appropriately sized and designed, meets this application. UV energy is used to break the organic bonds, leaving CO2 and water as the by-products.
All living organisms contain DNA. DNA provides the mechanism for all functions needed to sustain life. Microbial disinfection systems emit UV light that penetrates the outer cell membrane of microorganisms, passes through the cell body, reaches the DNA and alters the genetic material. The mircroorganism is thereby destroyed in a non-chemical manner and is unable to reproduce.
This is the most common application of UV light in water treatment. A pharmaceutical water system could have several locations where UV equipment would be installed. Some typical locations of installation would be post-carbon filter and pre-RO (Reverse Osmosis). When installed downstream of the carbon bed and/or directly upstream of the RO unit, a UV system can significantly reduce the microbial counts by destroying at least 99.9% of the bacteria present in the influent stream. Microbial disinfection is also recommended for the process distribution loop and DI water and supply to the storage tank.
Ozone is commonly used in the pretreatment area of a water system, as well as for sanitizing process and recirculating systems. Prior to the point-of-use, the residual ozone needs to be destroyed to ensure the process water is not compromised. UV technology is the preferred method for this application because it is a non-chemical, fast-acting mechanism.
Ozone destruct by ultraviolet light is simply the breaking down of the O3 molecule. It uses 254 nm wavelengths at approximately 90 mJ/cm2 power. As the O3 breaks down (dissociates) it releases an oxygen atom, which combines with other free oxygen atoms to form O2 molecules. This is the stable form of oxygen, which remains dissolved in the water. Ozone destruct UV units can be guaranteed to completely destroy the ozone in the water and thereby help to insure the integrity of the process and the product being produced.
While the addition of chlorine and chloramines to city water may control bacteria levels, they can cause undesirable effects such as the degradation of membrane filtration or RO (Reverse Osmosis). But popular methods of chlorine removal, such as carbon beds or chemical injection, have proven to be problematic. Sodium metabisulfite, when used for chlorine removal, involves replacing one chemical with another and creates food for micro-organisms. Activated carbon beds can be inefficient, vulnerable to channeling and provide breeding grounds for micro-organisms. Because of its clean operation UV is the preferred method of removing chlorine/chloramines in the pre-membrane filtration or RO make-up water stream.
Overall Benefits of UV
- Fast Kinetics – The application of UV light triggers a reaction almost instantly
- No Toxic By-Products – UV light does not result in the creation of harmful by-products
- Safe and Chemical-free – UV does not introduce any of the hazards associated with chemicals
- UV adds nothing to the water – UV does not alter water chemistry and its constituents, such as, pH, taste, odor, color, etc.