"SMART" MAGNETIC DRAW SOLUTES FOR FORWARD OSMOSIS DESALINATION

Abstract

Freshwater scarcity has drawn increasing attention due to the rapid growth of population and severe environmental pollution. This issue could be alleviated by desalinating seawater to provide potable water. Forward osmosis (FO), a natural occurring process that relies on draw solution to extract water from feed solution across a semipermeable membrane, has become a promising candidate for seawater desalination. Despite the rapid progress in the development of FO draw solutes, existing draw solutes still have disadvantages. Moreover, the application of FO in seawater desalination has yet to be investigated with eligible draw solutes. Therefore, the objectives of this project are (1) to develop stimuli-responsive (so-called “smart”) FO draw solutes with high osmolality and facile regeneration approaches; and (2) to apply these draw solutes in FO process to investigate their effectiveness especially in seawater desalination. In our study, hydrophilic polyelectrolyte-functionalized magnetic nanoparticles (MNPs), thermoresponsive MNPs, and thermoresponsive magnetic ionic liquids (MILs) have proven to be promising FO draw solutes in seawater desalination.