STUDY OF HUMIC-ACID ADSORPTION ON NANOFILTRATION MEMBRANES BY CONTACT-ANGLE MEASUREMENTS

Membrane fouling is a major problem, which extent depends on the respe ctive natures of the solute and membrane material. Membrane surface ch aracterization under different fouling conditions may help in understa nding the fouling mechanism. Such characterization was performed for t he 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 s urface energy of dry, hydrated and fouled membranes. The results revea l significant differences in the two membrane behaviours and informati on about the way that fouling material may be adsorbed on membrane sur face.