Desalination of simulated seawater by purge-air pervaporation using an innovative fabricated membrane

An innovative polymeric membrane has been invented, which presents a breakthrough in the field ofdesalination membranes. It can desalinate simulated seawater of exceptionally high concentration toproduce a high flux of potable water with over 99.7% salt rejection (%SR) in a once-through purge-airpervaporation (PV) process. A set-up was constructed for conducting the desalination experimentsand the effect of initial salt solution concentration (Ci) and pervaporation temperature (Tpv) on thewater flux (J ), %SR, separation factor, and pervaporation separation index were determined. Themembrane was prepared by the phase-inversion technique, of a specially formulated casting solutionconsisting of five ingredients, after which the membrane was subjected to a post-treatment by whichcertain properties were conferred. The results confirmed that the salinity of the pervaporate wasindependent of Ci (all %SR above 99.7). The best result was at Tpv ¼ 70 WC, where J varied from 5.97 to3.45 l/m2 h for Ci ¼ 40–140 g NaCl/l, respectively. The membrane morphology was confirmed to beasymmetric. The contact angle was immeasurable, indicating the membrane to be super-hydrophilic.Activation energies computed using Arrhenius law were, under all conditions investigated, less than20 kJ/mol K.