Incorporation of osmotic pressure in an integrated incremental model for predicting RO or NF permeate concentration

Consideration of concentration, recovery and osmotic pressure has been incorporated in a fully integrated diffusion based mass transfer model identified as integrated osmotic pressure model (IOPM). Osmotic pressure was incorporated into the model using correction coefficients that were calculated from boundary conditions, which were determined from the feed and concentrate streams osmotic pressures. Predicted permeate stream water quality using IOPM and the homogenous solution diffusion model (HSDM) were compared with and without consideration of osmotic pressure. IOPM was verified using independently developed data from full and pilot scale plants. The numerical simulation and statistical assessment show that osmotic pressure corrected models are superior to non-osmotic pressure corrected models, and that IOPM improved predictability of permeate stream water quality.