AWWA MTC61186

During long-term operation, the physical-chemical properties of high-pressure membrane surface can change as a result of membrane fouling, including surface charge, hydrophobicity, pore size and functionality. Bench-scale cross-flow flat sheet membrane units were employed for membrane fouling and rejection tests to examine the transport of non-ionic trace organic pollutants through virgin and fouled membranes. The rejection behavior of non-ionic compounds changed significantly as a result of membrane fouling. A time-dependent rejection trend was observed for virgin membrane specimens but was not remarkable for fouled membranes. Membrane fouling resulted in an increased rejection of non-ionic compounds and the rejection remained relatively constant over time. The fouling layer increased the size exclusion effect and eliminated the adsorption, partition and diffusion of hydrophobic non-ionic solutes through the membrane. Includes 10 references, table, figures.