Reverse Osmosis (RO) spiral wound membrane elements are to be used in the desalination of sea water that has a salt concentration of 42000mgTDS/L. Each element has a membrane area of 35.33m2. Each 6 elements will be housed in one UPVC vessel. 1. What is the osmotic pressure ( Posm ) of this sea water, Cf=42000mgTDS/L ? 2. What is (Qp) per membrane in m3/d for one spiral wound element from the used type if it has a permeability coefficient kw=7.0105kg/m3.s and requires a NDP of 13 bar to push the water through the membrane? 4.87/m2. 3. What is the total number of elements and the total number of 6 -element vessels needed to produce a total permeate water (Qp) of 6000m3/d ? 4. What is the concentrate salts concentration (Cc) coming from each of the 6element vessels if the salts concentration in the permeate Cp is 0.200 kg/m3, and the salts permeability coefficient of this type of membrane is 0.30107m/s ? 5. What is the value of Qc coming from each 6-element vessel and what is Qf for each vessel? 5. What is the rejection and recovery rates for each 6-element vessel? 7. What is the total daily brine that comes out of this RO plant