Development of Novel Thin-Film Composite Membrane through Interfacial Polymerization for the Pervaporation Desalination of Hypersaline Brine

Pervaporation systems implementing thin-film composite membranes for seawater treatment have shown promising performance. It is especially important when it comes to desalination of retentate after reverse osmosis. A typical reverse osmosis system has a recovery of 35 – 50 % due to high fouling of seawater, potentially leading to the discharge of significant amounts of water that otherwise could be recovered. This creates a need for a method that is suitable for the treatment of water with high salt content (7 – 10 wt%). Pervaporation is a novel method that can be utilized to achieve high purity and high recovery of the retentate from the reverse osmosis process. A method to fabricate pervaporation membranes for the treatment of high salinity brine was developed using interfacial polymerization. Various monomers as an aqueous phase for the interfacial polymerization were used, and the performance was compared between them and the control membrane. Number of monomers were tested to act as an organic phase, including diaminobenzene sulphonic acid, piperazine, zwitterionic guanazole derivative, and zwitterionic triamine monomer. However, among the tests, the best performance in terms of flux, at the same time maintaining high rejection, was achieved by the mixture of diaminobenzene sulphonic acid and m-phenylene diamine as an aqueous phase in a molar ratio of 3:1 and 1.2 wt%. The project has been carried out at King Abdullah University of Science and Technology, Saudi Arabia, in the Nanostructured Polymeric Membranes laboratory under the guidance of Prof. Suzana P. Nunes (Principal Investigator) and Maria di Vincenzo (Research Scientist).