REVERSE OSMOSIS DESALINATION WITH FORWARD OSMOSIS AND SOLAR COLLECTOR

摘要

Reverse osmosis desalination of sea water or brackish water, including a reverse osmosis desalination unit (20) and a natural or manmade or appropriately modified solar lake or pond (10) containing high concentration salt solution. A high concentration salt solution stream leaves from the said lake or pond (10) and returns to it, having lower salt concentration. The water evaporation from said lake, mainly due to the solar energy received by it, ensures that the salt concentration in said lake (10) is maintained to the required level. Actually, said lake or pond (10) operates as a large size and low cost solar collector. The required pressurization of the seawater or brackish water, entering at the one side of the semi-permeable membranes contained in the pressure vessels (22) of said reverse osmosis desalination unit (20), is achieved by the displacement imposed by the volume increase under very high pressure of the high concentration salt solution stream coming from said solar lake or pond (10) and, afterwards, returning to the lake (10), having lower salt concentration. Such volume increase under very high pressure of the high concentration salt solution stream, is realized, as the said high concentration salt solution stream absorbs water from another seawater stream (not related to the seawater stream that is going to be desalinated), through the semi - permeable membranes contained in the relevant pressure vessels of an additional osmosis unit (40), incorporated for this purpose and operating according to the Forward Osmosis Principle.