Studies on concentration polarization in a membrane module

Abstract

The effect of flow velocity and pressure of operation is closely related in any reverse osmosis (RO) I separation. Reduced separation at lower circulation velocity due to increased polarization could only be compensated by increased pressure of operation. A mathematical model to describe the flow condition through the experimental cell has been developed to predict the mass transfer coefficients for the separation of sugar. The predicted mass transfer limitations have been confirmed by experimental findings. The flow pattern, particularly the velocity profile in cross and axial direction. controls the concentration for distribution within a RO module. Thus the effect of flow rate on the concentration build up within the modules, i.e., polarisation effect has been predicted. This has been also used to predict the separation of sugar from an aqueous solution under different operating conditions and compared with the experimental results.