Correlating ultrafiltration membrane fouling with membrane properties, water quality, and permeate flux

The effect of membrane properties, feed water quality, and permeate flux on ultrafiltration (UF) membrane fouling was systematically investigated. Fouling tests were carried out with three types of commercially available UF membrane and a variety of influents. The membrane fouling was assessed by the normalized fouling rate (F-500). The results showed that the PVDF membrane with smaller contact angle was more resistant to membrane fouling than the PVC membrane. As for feed water parameters, significant correlations were observed between turbidity, total organic carbon, UV254, fluorescence intensity, and membrane fouling rates using Pearson Correlation Analysis. This was especially true for hydraulically irreversible fouling rate (F-irr). Moreover, significant correlations between permeate fluxes and membrane fouling rates were observed. With these correlations, the critical flux and critical flux for irreversibility were calculated. It was found that the critical flux is strongly depended on feed water composition rather than membrane properties. Particulate matter, with a size of 0.45-1.2m in diameter, was proved to increase the critical flux and critical flux for irreversibility.