Trevi Systems has designed an elegantly simple forward osmosis system using a proprietary membrane and a unique draw solution that allows the draw solute to be separated from the recovered water using thermal heat. Forward Osmosis (FO) is a natural process and occurs in the cells of all living things when liquids of differing solute concentrations are separated by a semi-permeable membrane. FO differs from Reverse Osmosis (RO) in that natural osmotic pressure, resulting from the difference in solute concentration in the two liquids, is the sole driving force for the transport of pure water across a membrane. Water is driven through a semi-permeable membrane in the RO process, using hydraulic pressure resulting in significant energy expenditure, and hence cost in producing the desalinated product. With FO, osmosis is allowed to occur naturally, without external force, resulting in a very low energy method for desalinating water. FO provides a number of advantages over RO for seawater desalination in addition to the energy savings. Lower fouling of the membrane provides longer lifetime and lower maintenance costs. Other advantages of FO include higher maximum feed water recoveries and a reduced level of pretreatment.