Application of the solution-diffusion-film model for the transfer of electrolytes and uncharged compounds in a nanofiltration membrane

Abstract

Abstract A nanofiltration (NF) process applied to both single solutes (charged and uncharged) and electrolyte mixtures formed by a dominant salt and trace ions was evaluated in this work. Experiments were performed in a pilot plant using a 200 Da cut-off spiral-wound polymeric membrane. The marked differences in rejection of the same trace ion in the presence of different dominant salts were successfully described by the solution-diffusion-film model (SDFM). SDFM was also applied to study the rejection variation of single solutes such as betaine, sucrose, lactic acid and citric acid, and their permeate fluxes, under different applied pressures.