Effects of different potential functions on modeling of RO membrane performance by use of an advanced model

Modeling of reverse osmosis membranes is essential for progress in membrane separation technology. Effects of a new potential function on the modified surface force pore flow (MD-SF-PF) model were investigated by Moradi et al. in 2012. The main purpose of this research was to study the effects of other potential functions on the advanced and extended form of the MD-SF-PF model (i.e. the EX-MD-SF-PF model). The results obtained were compared by use of an objective function and by using the root-mean-square deviation. The best potential function was finally selected and a new model was proposed. The complex and nonlinear equations of the EX-MD-SF-PF model were solved by use of advanced numerical methods, for example finite difference and the finite volume. The proposed model, besides enabling excellent prediction of the performance of membranes, for example separation factor, and solvent and pure fluxes, has much better root-mean-square deviation than the EX-MD-SF-PF model. Profiles of potential function against pore radius and pore length were plotted and good trajectories were obtained. Profiles of solute concentration at the beginning, middle, and end of a pore were calculated and compared. The velocity profile of the permeating solvent was calculated and plotted. Most of the experimental data were predicted by use of the model.