Fouling research with polymeric membranes has demonstrated that various natural organic matter (NOM) fractions contribute differentially to membrane fouling behavior. However, limited studies exist analyzing the sensitivity of the MFI-UF to be used as a tool to differentiate NOM fouling components. The results here indicate that MFI-UF is a suitable tool for assessing NOM fouling. Specifically, NOM fouling potential was in the order of organic proteins (as BSA), polymers (alginate), and humic acid, respectively. Further, a mixed solution containing BSA, alginate and humic acid fouled similarly to the BSA solution indicating the high fouling potential of organic proteins in membrane systems. The MFI-UF value was found to increase by > 30% with increasing pressure (1–3 bar) and decreasing temperature (35°C–5°C). The filtered water volume was found to correlate with the MFI-UF values indicating the dependency of the method on testing conditions. Incorporating water viscosity and pressure values against normalized conditions (20°C and 2 bar) with the standard MFI-UF equation was found to be useful to estimate MFI-UF values at variable operating conditions, thus, enhances the potential application range of MFI-UF as a fouling index for NOM.

BSA, Humic acid, MFI-UF, Sodium alginate, Temperature
Desalination and Water Treatment
Department of Civil and Environmental Engineering

Alresheedi, M.T. (Mohammad T.), & Basu, O. (2018). Application of MFI-UF fouling index with NOM fouling under various operating conditions. Desalination and Water Treatment, 133, 45–54. doi:10.5004/dwt.2018.22999