Nanofiltration of NaCl solutions using a SPPO membrane (BQ01) Part 2. Membrane behavior with an electric field Original Research Article

Experimental investigation of electric field enhanced-nanofiltration (called electro-nanofiltration) is reported for sodium chloride solutions. Electro-nanofiltration performance was quantified under several conditions of concentration, electric potential magnitude and polarity. As reported in Part 1 of this study [1], the membrane evaluated, namely BQ01, displayed a different response with respect to pure water and NaCl solution permeation. In this part the influence of various electric fields on BQ01 performance is reported. The other operating parameters are set up identically as the previous study. Electric field application was found to outshine the increase in effective pore size that was usually observed with BQ01 membranes in the presence of electrolytes (without an electric field). As a result, dynamic permeability decreases when an electric field is applied compared to when no electric field is applied. The evolution of the separation factor and pH regarding concentration, electric potentials and polarity were also reported.