AWWA WQTC58926

Low-pressure membrane technologies are playing an increasingly important role in the treatment of water sources used for drinking purposes. These membranes are generally classified as either microfiltration (MF) or ultrafiltration (UF). Although it is generally assumed that UF membranes provide effective virus removal and MF membranes do not, these classifications do not accurately describe their capabilities to remove a wide array of microorganisms. Nominal pore size designations can also provide spurious interpretations of microbial removal efficacy. As a result, an AWWARF-funded study was undertaken to create a bench-scale methodology for characterizing membranes based solely on their capability to remove a variety of microorganisms. The specific objective of this study was to construct a bench-scale, low-pressure membrane filtration testing unit, and characterize low-pressure membranes based upon their capability to remove selected microorganisms. Specifically, the impact of transmembrane pressure, viral loading on the membrane and reported membrane molecular weight cutoff (MWCO) or pore size on microbial removal was evaluated. Specific materials and methods included: low-pressure membrane testing units and membrane modules; disinfection of experimental system; organisms used for bench-scale challenge experiments; microbial challenge experiments; determination of specific flux; and, analytical methods. Includes 6 references, table, figures.