Filtration of recombinant Norwalk virus particles and bacteriophage MS2 in quartz sand: Importance of electrostatic interactions

Norwalk virus is known to be transmitted through groundwater, yet the environmental factors that facilitate its interstitial transport in subsurface systems are not yet clear. This paper investigates the filtration and surface charge of recombinant: Norwalk virus (rNV) particles that ate morphologically and antigenically similar to live Norwalk strains bur lack nucleic acid and are therefore noninfectious. In contrast to bacteriophage MS2, a common surrogate for waterborne viral pathogens, the surface charge of rNV particles and their filtration in packed beds of quartz sand are strongly influenced by pore water pH over the environmentally important range of pH 5-7. From a mechanistic perspective, these results suggest that the physicochemical filtration of the Norwalk virus is highly dependent on the nature and magnitude of electrostatic interactions that develop between the virus and filter media. Furthermore, because MS2 and the rNV particles differ significantly with respect to their electrostatic properties, MS2 may not mimic the subsurface filtration of Norwalk virus in natural systems.