Experimental and Modeling Assessment of the Roles of Hydrophobicity and Zeta Potential in Chemically Modified Poly(ether sulfone) Membrane Fouling Kinetics

This study investigated the roles of hydrophobicity and zeta potential of polymer membranes and foulants on membrane fouling during filtration. A series of chemically modified poly(ether sulfone) (PES) membranes were used to evaluate filtration performance with bovine serum albumin (BSA) and humic acid (HA) employed as model foulants. Hydrophobicity and zeta potential of both membranes and foulants were measured and incorporated in the surface interaction energy calculation by the extended Derjaguin-Landau-Verwey-Overbeek (EDLVO) theory analysis. Foulant deposition rate was then calculated based on particle transport equation and interaction energy. Membrane fouling rates, indicated by the decrease of permeate flux, were well correlated (R² = 0.74-0.99) with the foulant deposition rates. This correlation indicates that both electrostatic interaction and hydrophobic interaction played decisive roles in membrane fouling. Our results have important implications for elucidation and prediction of the structure-property-performance relationship of diverse chemically modified membranes and may promote the rationale design and development of functional membrane filtration systems.