Modeling and Prediction of Fouling in Reverse Osmosis by Combining Film Theory and Diffusion Transport through the Membrane

Abstract

Fahed M Alsubaie and Yaala S Assiri

The accumulation of salts on the high-pressure side of the reverse osmosis membrane surface is known as concentration polarization. The reverse osmosis membrane rejects dissolved salts, resulting in the creation of a salt layer on the membrane surface. As a result, the salt concentration at the membrane surface is elevated to a level that exceeds the bulk salt Concentration polarization significantly affecting the performance of the reverse osmosis process. The osmotic pressure at the membrane surface is increased, resulting in a decrease in water flux and an increase in salt leakage. High salt concentration can lead to a decrease in membrane lifetime. This research aims to apply a combined theory of film and diffusion transport through the membrane. Flux through the reverse osmosis process can be described by coupling the solution diffusion transport model with film theory. Limiting data on water, salt, and membrane properties, as well as mass transfer coefficients, is an important factor in formulating concentration polarization. The primary goal of this research is to develop a predictive mathematical model for fouling in reverse osmosis desalination processes and demonstrate the effects of physical and operating parameters on permeate velocity, wall concentration, concentration polarization factor, and boundary layer thickness. This permeate velocity equation was used to predict and evaluate the permeate water flux values to validate the obtained model with field data from seawater pilot plant in our campus of KACST.

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