METHOD OF OSMOTIC PRESSURE FREE REVERSE OSMOSIS FOR ENRICHING AQUEOUS SOLUTION TO HIGH CONCENTRATION USING HYDRAULIC PRESSURE

摘要

The present invention relates to a method for concentrating an aqueous solution at low pressure in an osmotic pressure-free state and, more particularly, to a method for concentrating a solute-containing aqueous solution to be concentrated at low pressure in an osmotic pressure-free state. A method for concentrating an aqueous solution at low pressure in an osmotic pressure-free state according to the present invention comprises the following steps. (a) A reverse osmotic pressure separator discharges water in a solute-containing aqueous solution to be concentrated to the outside, and transfers a concentrated aqueous solution to an osmotic pressure-free concentrator. (b) The osmotic pressure-free concentrator including a feed chamber or a draw chamber partitioned by a reverse osmotic pressure membrane or a forward osmotic pressure membrane further concentrates the concentrated aqueous solution. (c) The osmotic pressure-free concentrator collects solute and water from the further concentrated aqueous solution in the osmotic pressure-free concentrator, respectively. When a method for concentrating an aqueous solution at low pressure in an osmotic pressure-free state is used, energy consumption can be reduced, the aqueous solution can be concentrated until concentration of the solute or a maximum saturated aqueous solution of the solute reaches 100% without using an extracting solvent, and there is no need to use a separated osmotic pressure deriving solution.