The nanofiltration of 0.02-1.0 mol/dm(3) NaNO3 solutions at pH 4.0 and 8.0 using a dynamically-formed zirconium hydrous oxide-polyacrylate (FIP-ZPA) membrane has been investigated at 318 K. The practical transport coefficients for hydrodynamic permeability (L-p), reflection (sigma) and solute permeability (omega), were calculated from the nanofiltration results using irreversible thermodynamic equations.