Problem 1. In a reverse osmosis system, given in Figure 1 , fresh water will be obtained from a salt lake which includes only sodium chloride (NaCl) with a concentration of 8000mg/at25C. The density of salt water (w) is 1g/cm3. The total daily lake water flow rate (Qin) introduced to reverse osmosis system is 24000m3/d. The reverse osmosis system in Figure 1 includes 4 membrane units, which are in horizontal cylindrical shapes and each filter includes membrane sheets with a surface area of 5m2. The permeability coefficient (An) and salt passage constant (Bn) of membrane are given as 3kg/m2.5.atm and 104m/s, respectively. The applied pressure (P) to membrane is 10 atm. Based on information given in the problem, calculate: a) Water flux (Fw) to each membrane as m3/m2. s and fresh-water production efficiency as percentage. (15p) b) The salt concentration at membrane output (Cout) as g/m3 and percent salt rejection efficiency. (10p)