Problem 3

An RO membrane system is used to provide 10 million liters per day from a water source

containing NaCl at a concentration of 17,500 mg/L (299 mM) at 20 deg C. Assuming a trans

membrane pressure of 50 bars, recovery of 80%, a manufacturer supplied Kw = 15 L/m² -hr-

bar, Ks = 1 L/m²-hr, single stage operation, calculate the following design parameters. Use an

arithmetic average of module feed and concentrate concentrations in your calculations and

assume the osmotic coefficient is equal to 1.

(A) Rejection

(B) Membrane surface area required (m²),

(C) The feed flow rate to the system (L/d)