Astudent tested a ro membrane performance. when the feed was pure water and the applied hydraulic pressure was 5 bar, he measured a membrane water flux of 25 lmh. then he added some nacl into the feed to reach a concentration of nacl 10 mm in the feed solution. after stabilized, he measured the permeated concentration was 0.1 mm and the water flux dropped to 22 lmh at the same applied hydraulic pressure. calculate: (1) membrane water permeability; (2) membrane salt permeability; (3) concentration polarization factor under the current testing conditions. (hints: first find/derive the equation for calculating a and b values)