How ultraviolet (UV) and ultrafiltration (UF) work

• Process: UV purification uses ultraviolet-C (UVC) light, which has a wavelength of 254 nm, to inactivate harmful microorganisms. As water flows through a chamber containing a UV lamp, the light penetrates the microorganisms’ cell walls and scrambles their DNA and RNA. This renders them unable to reproduce and cause illness.
• What it removes: UV is a highly effective method for eliminating bacteria, viruses, and other pathogens, destroying up to 99.99% of these microbes.
• What it doesn’t remove: UV is a disinfection process, not a filtration one. It does not remove physical impurities like sediment, dirt, or other dissolved solids. 

• Process: Ultrafiltration is a membrane-based technology that uses hydrostatic pressure to push water through a semi-permeable membrane with microscopic pores, typically ranging from 0.01 to 0.1 microns. This acts as a physical barrier, trapping larger contaminants while allowing water and dissolved minerals to pass through.
• What it removes: UF effectively removes suspended solids, bacteria, protozoa (like Cryptosporidium and Giardia), and some viruses.
• What it doesn’t remove: The UF membrane’s pores are not small enough to block dissolved salts, chemicals, or other ions, as those are smaller than the pore size. 

The combined UV-UF system: A multi-barrier approach

1. Water enters UF stage: The raw water first passes through the ultrafiltration module, where physical contaminants like suspended solids, turbidity, and most bacteria and viruses are physically blocked by the membrane.
2. UF output to UV stage: The filtered water, or permeate, from the UF module is then sent to the UV disinfection chamber.
3. UV stage for sterilization: Here, the UVC light attacks and neutralizes any remaining microorganisms that may have passed through the UF membrane or been introduced downstream.
4. Final water output: The water leaving the UV chamber is both filtered and sterilized, making it safe for a wide range of applications. 

Key benefits of the combined system

• Comprehensive purification: The combination provides both superior physical filtration and highly effective chemical-free disinfection.
• Enhanced performance: UF’s ability to remove turbidity and solids ensures the water is clear enough for the UV light to be fully effective, as any “shadows” from particles could otherwise shield microorganisms.
• Improved longevity: By removing particulate matter, the UF stage protects downstream equipment, including the UV quartz sleeves, from fouling and scaling. This extends the lifespan of the UV lamps and reduces maintenance.
• Chemical-free disinfection: Neither technology relies on chemical additives, which eliminates the risk of harmful disinfection by-products and preserves the water’s natural taste and odor.
• High efficiency: The entire process is continuous and rapid, with a small physical footprint, making it suitable for a variety of scales and flow rates.
• Redundancy for safety: The multi-stage process provides a valuable safety net. If one stage were to underperform slightly, the other stage is there to capture or neutralize any missed contaminants.

Applications

• Drinking water treatment: Ensuring the safety of water supplies for homes, businesses, and entire communities.
• Food and beverage industry: Producing ultra-pure water for processing, bottling, and cleaning.
• Pharmaceutical manufacturing: Creating high-purity water for sensitive processes where microbial contamination must be eliminated.
• Wastewater treatment: Providing an advanced stage for water reclamation and reuse applications.
• Hospitality and healthcare: Ensuring clean, safe water for hotels, resorts, and medical facilities.
• Pre-treatment for RO: Serving as an excellent pre-treatment step for reverse osmosis systems, which helps prevent fouling of RO membranes.