The traditional method for determining whether a membrane is considered an
ultrafiltration (UF) or microfiltration (MF) membrane is based upon the molecular weight cutoff
of the membrane or the nominal pore size. Microbial removal performance does not currently
play a quantitative role in determining whether a membrane is classified as MF or UF. This
leads to ambiguity in the classification of low-pressure membranes. The overall goal of this
AwwaRF-funded research was to develop a systematic performance testing protocol and
specification for low-pressure membranes with respect to removal of viral and submicron
bacterial pathogens with various water qualities and operating conditions. Pilot studies were
conducted at the Atlanta Fulton County Water Treatment Plant, Georgia with a continuous
microfiltration (CMF) unit (hollow fiber, PVDF membrane) to evaluate its capability to remove
microorganisms under selected water quality and operational conditions. The pilot unit was fed
with dechlorinated finished water, raw water from the Chattahoochee River, and filtered water.
The microorganisms tested were MS2 phage, PRD1 phage and Pseudomonas diminuta. Under
clean water conditions (using dechlorinated finished water), the removal of PRD1 phage ranged
between 1.2 and 1.6 log, while negligible removals of MS2 phage were observed. Complete
removal of Pseudomonas diminuta (5 Log) was observed under the same conditions. Short- and
long-term fouling experiments with raw and filtered water showed that cake layer formation 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. Includes 12 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 670 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 19 |
| Published : | 06/15/2003 |
