Influence of operating pressure on concentration polarization layer resistance in revers osmosis

Serhii Huliienko,Oksana Leshchenko

doi:10.24263/2304-974x-2019-8-1-13

Abstract

Influence of operating pressure on concentration polarization layer resistance in revers osmosis

Highlights

The experimental examination of hypothesis about linear dependence of concentration polarization resistance from pressure was carried out and the influence of hydrodynamic condition on this resistance is determined
The membrane resistance during reverse osmosis of deionized water did not change with applied pressure in experimental conditions and was equal Rm=7,549·1013 m-1
The concentration polarization layer resistance (Rcp) increased from 0.65–1.29·1013 m-1 to 1.46–1.83·1013 m-1 with applied pressure increasing from 0.2 MPa to 0.6 MPa and from 0.65–1.46 m-1 to 1.29–1.83·1013 m-1 with increasing of feed concentration from 100 mg/dm3 to 600 mg/dm3

Summary

Materials and methods

Materials The experiments were carried out with using of commercially available reverse osmosis membrane modules Dow Filmtec TW30-1812-50 (made in USA). Since in membrane module the flow rate change with channel length due to penetration of a part of the feed solution through the membrane in present research the mean value calculated from the permeate and retentate flow rate was used as a determining velocity, m/s [27]: Lf Lr we (5). Determination of concentration polarization layer resistance The calculations of resistance were carried out based on transmembrane flux value which according to [12–14] can be described by equation, m3/(m2·s): Δp Δπ. Whereas the Rm is known, the concentration polarization resistance could be obtained from measurements results from dependency, found from the transformations of equations (7) and (8): Rcp. for the solution with known values of osmotic pressure and dynamic viscosity the concentration polarization layer resistance could be determinated experimentally. These values could be determinated from reference literature [30–31]

Results and discussion

Introduction

Conclusion