AWWA MTC61155

In literature, natual organic matter (NOM) fouling of ultrafiltration (UF) membranes is described due to the deposition of mostly high molecular weight organics, bigger than the MWCO-value of the membrane, like polysaccharides. A former PWN study indicated that the low molecular weight organics and metal complexes rather than the high molecular weight organics were responsible for the acceleration in film formation of these HMW fractions and, therefore, fouling. In this study bench-scale experiments were carried out to reduce the fouling potential of IJssel Lake water by: removing HMW organics like polysaccharides, with enhanced coagulation, according to literature; removing LMW organics like acids and humics, with ion exchange, according to hypothesis PWN; and, reducing the negative surface charge of the membrane or using opposite charge to promote electrostatic exclusion. The study concluded that the removal of LMW organics (lower then the MWCO-value of the membrane) with the same amount of HMW organics leads to a much lower fouling potential than the removal of HMW organics alone. The combination of a relatively high positively charged hydrophilic membrane and the removal of LMW fractions with an anion resin (MIEX) results to a high gross flux rate at almost no fouling. However, results have been achieved during a relatively short time on bench-scale. Extended pilot research is recommended. Includes 13 references, tables, figures.