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In membrane applications for water treatment, natural organic matter (NOM) hasbeen found to be a major foulant together with colloids. Characterizing clean andNOM-fouled membranes with respect to charge properties enables us to understandfouling mechanisms and to reduce fouling by controlling concentrationpolarization and NOM adsorption onto the membrane surface. This study includesthe characterization of clean and NOM-fouled membranes in terms of size andfunctionality. To determine the pore size distribution (PSD) of a membrane, thefractional rejection of polyethylene glycols (FR-PEG) method was used, and theatomic force microscope (AFM) was also used for comparison. These results werenot shown in this paper, but will be presented at the membrane conference. Todetermine the membrane surface charge, zeta potential measurement (by theelectrophoresis measurement method using a electrophoretic-light scatteringspectrophotometer) and a direct titration method (by photentiometric titrationmethod using a micro titrator) were used. The attenuated refractive fouriertransform infrared (ATR-FTIR) spectroscopy was used to determine the functionalgroup types of solutes (i.e., humic substances, polysaccharides, proteins, orothers) adsorbed on the membrane surface. Through these membranecharacterizations, influencing factors formembrane performance can be determined in terms of solutes rejection as well as fouling. Thegoals of this study are: to characterize membranes in terms of surface charge andpore size distribution; to investigate electrostatic interactions for betterunderstanding of membrane performance and fouling (by combining NOM filtrationand adsorption results with the characterization of the membrane chargeproperties); and, to determine influencing mechanisms for membrane foulingthrough the characterizations of both NOM foulants and fouled membranes. Includes figures.

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Edition: Vol. - No. Published: 05/01/2001 Number of Pages: 7File Size: 1 file , 300 KB