Study of humic acid adsorption on nanofiltration membranes by contact angle measurements

Membrane fouling is a major problem, which extent depends on the respective natures of the solute and membrane material. Membrane surface characterization under different fouling conditions may help in understanding the fouling mechanism. Such characterization was performed for the case of humic substances filtered on two nanofiltration membranes, using special contact angles measurements. The measured contact angles allowed the calculation of polar and non-polar contributions to the surface energy of dry, hydrated and fouled membranes. The results reveal significant differences in the two membrane behaviours and information about the way that fouling material may be adsorbed on membrane surface.