AWWA ACE59945

The primary goal of this AwwaRF funded research was to develop a systematic performance testing protocol for characterizing MF and UF membranes based on their ability to reject viral and submicron bacterial pathogens with various water qualities and operating conditions. Seeding challenges were conducted with the continuous microfiltration (CMF) and submerged-continuous microfiltration (CMF-S) pilot units at the Atlanta Fulton County Water Treatment Plant, Georgia (AFCWTP, drinking water facility with raw surface water), and the Scottsdale Water Campus, Arizona (SWC, water reclamation facility using secondary clarified effluent). These units were both equipped with 0.1 &181;m PVDF hollow fiber membranes. MS2 and PRD1 phages were used to quantify the viral removal, while Pseudomonas diminuta was used to characterize the bacterial removal. Results obtained with the pilot units under clean water conditions (dechlorinated tap water) have shown that Pseudomonas diminuta was completely removed (~ 5.0 log-units). PRD1 phage removal varied between 0.3-1.8 log and removal of MS2 phage varied between 0-1.1 log. Short- and long-term fouling experiments with raw, filtered water and secondary effluent showed that deposition (cake) and pneumatically-irreversible fouling can induce additional phage removal to a variable extent depending upon the size of the microorganism, the feed water quality and the decline in specific flux. Microbial rejection results from both these facilities using waters of varying quality and membrane types are compared and presented. The increase in removal of PRD1 phage due to membrane fouling appears to be correlated to the decline in specific flux. Includes 17 references, tables, figures.