WaterSolutions Microorganisms

Protection from water-borne pathogens like Cryptosporidium, Giardia and other microbes that can make individuals sick in the short term is a key requirement for drinking water providers. As more water is sourced from surface water or groundwater that is under the influence of surface water, while at the same time some locations are looking to reduce the levels of disinfection chemicals other routes for pathogen control are being met via filtration. The physical removal of microorganisms by Ultrafiltration (UF), particularly those like cryptosporidium which is somewhat resistant to primary disinfection practices such as chlorination and chloramination.

DOW™ UF SFD 2880 for Cryptosporidium Removal. The physical removal of microorganisms by UF, particularly those like cryptosporidium which are somewhat resistant to primary disinfection practices such as chlorination and chloramination, offer a valued alternative for municipal drinking water systems. The development of the “Long Term 2 Enhanced Surface Water Treatment Rule” (LT2ESWTR) guidance manual by the U.S. Environmental Protection Agency(¹) offers a better understanding of how the membrane process can be applied for drinking water treatment.

For public drinking water systems that use a surface water or a ground water under the direct influence of surface water, the DOW™ SFD 2880 UF module as tested by the NSF under the Environmental Technology Verification (ETV) using B. atrophaeus challenge, resulted in a minimum overall mean LRV is 5.89 with the minimum individual sample point LRV of 5.77 (²).

The DOW™ UF SFD 2880 meets the criteria in order to receive removal credit for Cryptosporidium by holding third party verification. For a municipality to secure the removal credit two follow-up steps are required by the specific site. These two key on-site follow-ups are the verification of similar removal from the specific feed waters by direct integrity testing and a program to demonstrate continuous indirect integrity monitoring during operation. More details and the product specifications for the 0.03um, PVDF, outside-in SFD 2880 module can be found on the Dow Water & Process Solutions Product data sheet(³)

1. U.S. EPA 815-R-06-009, “Membrane Filtration Guidance Manual” (Nov. 2005)
2. B. Bartley, AWWA RTP Meeting, “Membrane Product Specific Challenge Test
3. Dow Water & Process Solutions Product Literature Form 795-00030-1109 DOW™ Ultrafiltration Modules.