Forward Osmosis and Pressure Retarded Osmosis: Recent Progress and Challenges

This presentation will describe the processes of forward osmosis and pressure retarded osmosis and their potential for sustainable production of water and power.  These processes are driven by the natural flow of water through a semipermeable membrane based on osmotic pressure gradient, rather than through the application of hydraulic pressure to the feed stream.  Ongoing efforts in forward osmosis for desalination, water reuse, and treatment of high salinity brines will be described as well as the application of pressure retarded osmosis for generation of electricity from salinity gradients.  Special emphasis will be given to membrane design and performance, solute and water flux behavior, fouling and fouling mitigation strategies, and overall process performance.  Critical challenges for the implementation of these processes and research needs will also be discussed.  In doing so, it is the hope that this presentation will motivate academic research, commercial implementation, and discussion of other potential uses of forward osmosis and pressure retarded osmosis.