Filtration media including at least one layer of nanofibers having average
diameters less than 1000 nanometers with optional scrim layer(s) are
disclosed for filtering particulate matter in liquid. The media achieve
flow rates of at least 0.055 L/min/cm.sup.2 at relatively high levels of
solidity. The media have also advantageously been found to have
non-diminishing flow rates as differential pressures increase between 2
psi (14 kPa) and 15 psi (100 kPa).