Adsorptive virus removal with super-powdered activated carbon

We investigated the removal of bacteriophages by adsorption on commercially available powdered activated carbon (N-PAC, median diameter >10 μm) and super-powdered activated carbon (S-PAC, median diameter 0.7–2.8 μm). N-PACs failed to remove the virus in Milli-Q water buffered with 100 μM Ca 2+ , but some S-PACs successfully removed it under the same condition. Three factors contributed substantially to virus removal: a smaller electrophoretic repulsive force between the virus and the PAC particles, a large proportion of pores 20–50 nm in diameter, and a greater hydrophobicity of the virus surface.