13.10. APPLICATIONS, EQUIPMENT, AND MODELS FOR REVERSE OSMOSIS
13.10A. Effects of Operating Variables
In many commercial units, operating pressures in reverse osmosis range from about 1035 up to 10350 kPa (150 up to 1500 psi). Comparison of Eq. (13.9-2) for solvent flux with Eq. (13.9-4) for solute flux shows that the solvent flux Nw depends only on the net pressure difference, while the solute flux Ns depends only on the concentration difference. Hence, as the feed pressure is increased, solvent or water flow through the membrane increases and the solute flow remains approximately constant, giving lower solute concentration in the product solution.
At a constant applied pressure, increasing the feed solute concentration increases the product ...