(146f) Applied Aspects of Forward Osmosis Desalination

Forward Osmosis (FO) uses an osmotic driving force to extract water from water containing dissolved species including salt water. This experimental work evaluates the performance of the FO process in seawater desalination using various membranes to study the permeability and productivity of the FO process. Moreover, the work investigates the effect of temperature, pH, membrane surface area, and saline water concentration on the permeability, productivity and the overall performance of the FO desalination process. Since permeability increases with temperature theoretically, the optimum temperature for the FO operation is determined. Also, the surface area of the membrane is varied to study permeability and fouling of the membrane. The concentration of saline water is also varied to investigate for the operating range of the FO process and study the performance of the process at high saline water concentrations. Preliminary results shows that water flux is relatively low due to the weaker driving force induced by the seawater draw solution; however, feed water quality has a minimal effect on water flux through the FO membrane. The bench-scale batch experiments show minimal fouling of the FO membrane. Results indicated that draw solution concentration has minimal effect on the flux but flow velocity affects water flux in both sides of the membrane. Work in progress is directed at testing the performance of the process with several membrane and draw solutions.