Nanofiltration Membranes for Removal of Color and Pathogens in Small Public Drinking Water Sources

Small public water supplies that use surface water as a source for drinking water are frequently faced with elevated levels of color and natural organic matter (NOM) that are precursors for chlorinated disinfection byproduct (DBP) formation. Nanofiltration (NF) systems can prevent DBP formation by removing color and NOM before chlorination. Research studies were conducted on Fall Lake water in Minnesota and dechlorinated potable water spiked with NOM in Ohio by using nanofiltration (Fyne process). Several types of tubular membranes with various molecular weight cutoffs were studied. The effectiveness of the Fyne process in producing safe drinking water was gauged by measuring the removal efficiency of total organic carbon, color, 2–3 micron particles, Bacillus subtilis as a surrogate for bacteria removal and MS2 bacteriophage as a surrogate for virus removal. Results of tests conducted under controlled laboratory conditions and field conditions indicated that Fyne process NF membranes could be used by small system drinking water treatment systems for DBP precursor and pathogen removal.