MFI―UF constant pressure at high ionic strength conditions

It has been clearly proven that particles much smaller than 0.45 μm are responsible for colloidal fouling of the surface of RO and NF membranes. As a consequence the predictive value of SDI and MFI (0.45 µm) in particulate fouling is doubtful. To overcome this deficiency the MFI–UF has been developed, making use of ultrafiltration membrane with different pore sizes and measured at constant pressure or constant flux. The MFI–UF has not yet been tested and evaluated for brackish/estuarine water and seawater. The objective of this work is to investigate the effect of salinity on the MFI–UF constant pressure for higher ionic strength conditions present in brackish/estuarine waters and seawater prior to application to reverse osmosis. For this, specific objectives are to ascertain the effect of pressure and ionic strength on various membrane filters. Membrane filters consisting of three membrane materials were tested – PES, RC, and PVDF – with different MWCOs (100, 30 and 10 kDa and 0.1 µm for PDVF). Ultra pur...