Recovery of sodium gluconate from model solutions by reverse osmosis Original Research Article

Recovery of sodium gluconate from aqueous solutions was studied batchwise in a pilot plant equipped with spiral-wound cellulose acetate or thin-film composite reverse osmosis membranes. The thin-film composite and cellulose acetate membranes had intrinsic membrane resistances (Rm) of (3.8±0.1)×1014 and (2.42±0.05)×1014 m−1 and water fluxes of 60±2 and 91±2 dm3 m−2 h−1 at a feed input absolute pressure of 41 bar and 40°C, respectively. Osmotic pressure was found to be the major resistance to permeation. A model based on the resistance concept was able to predict solvent permeation flux within 5–11% for both membranes.