Water flux through a polyamide membrane in an RO module is 115 L/m2.h at a pressure differential of 110 bar. Calculate the water and solute flux if used to desalinate at 4%NaCl solution at a pressure difference of 110 bar. (a) Calculate the water and solute flux if used to desalinate a 4%NaCl solution at an operating pressure difference of 80 bar. The salt rejection is nearly 100%, and the osmotic pressure of 3%NaCl is 17.62 bar. The polarization modulus can be taken as unity. (b) The same module is used to desalinate a 3.5% solution of another salt. The polarization modulus is estimated to be 3 , and the salt rejection is 0.99 . If the osmotic pressure of the solution is 18 bar, calculate the water and salt flux at an applied pressure difference of 75 bar