Low pressure membranes (LPMs), ultrafiltration (UF), and microfiltration (MF) are
increasingly being used globally for drinking water treatment to remove particulates and
microbiological contaminants. Viruses in drinking water are smaller than the nominal pore size
of MF and some UF membranes. Even so, laboratory studies and field experience demonstrate
that enteric viruses are indeed removed by LPMs. To perform properly, membranes must remain
intact. Imperfections introduced during manufacturing and handling typically cause holes or
macro-pores in membrane surfaces. Compromised membranes allow passage of viruses and
other contaminants across the membrane barrier directly into permeate.
A numerical particle tracking model was developed to assess the significance of holes and large
macro-pores on virus passage through LPMs. Modeling predictions are compared to the results
of virus rejection studies using two MF and two UF flat-sheet membranes challenged with MS2
and PRD1 phage. The membranes tested have different characteristics (monomer, nominal pore
size, thickness, hydrophobicity, and resistance). Large hole challenge tests were conducted using
needle-compromised membranes. A small hole challenge test was conducted on an Excimer
laser-drilled UF hydrophilic membrane. This is the first such model to assess virion passage through small holes in polymeric membrane
surfaces. The implications for full-scale MF and UF systems and recommendations for future
research are presented in this powerpoint presentation. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 2.1 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 23 |
| Published : | 11/01/2008 |
