(487a) Novel Hydrophilic Cast Nylon 6,6 Microfiltration (MF) Membrane Supported Thin Film Composite (TFC) Membrane for Engineered Osmosis (EO)

Clean water and energy are essential for public health and economic prosperity. Recent studies show that Engineered Osmosis (EO) may be a viable technology for desalination, water and wastewater treatment, and power generation. However, the absence of a membrane designed for such processes is a significant obstacle hindering further advancements of this technology. Conventional thin film composite (TFC) reverse osmosis (RO) membranes yield very poor permeate water flux in EO due to their thick, dense and hydrophobic support layers resulting in internal concentration polarization (ICP). In this study, a novel TFC EO membrane has been designed using a conventional cast nylon 6,6 microfiltration (MF) membrane from 3M^® as the support in order to minimize ICP effect. The ultra-thin polyamide (PA) selective layer has been built via in situ interfacial polymerization. Results show that for the first time, an intrinsically hydrophilic cast-film supported TFC membrane has been successfully fabricated with defect-free PA film. The resulting TFC membranes made on piperazine and m-phenylenediamine showed matched permselectivity performance with two commercial RO membranes (The Dow Water & Process Solutions NF 270 and SW-XLE), respectively. When this new TFC membrane was applied in EO, it showed higher osmotic flux and 10X lower salt flux than commercial forward osmosis (FO) membranes. The relatively high osmotic flux of this new TFC membrane can be attributed to its good wetting ability and open porous structure of the support. These qualities make it an excellent candidate for use in engineered osmosis processes including in seawater desalination and power generation.