摘要 |
A forward osmosis apparatus is improved. A forward osmosis apparatus, comprising a diluting means for bringing a feed solution and a draw solution comprising a cation source and an anion source in an ionized state into contact through a semi-permeable membrane and diluting the draw solution with water separated from the feed solution by means of the semi-permeable membrane;
a separating means for separating the draw solution that has been diluted by the diluting means into the cation source and anion source and into water; and
a dissolving means, returning the cation source and the anion source that have been separated by the separating means to, and dissolving the cation source and anion source in, the draw solution that has been diluted;
wherein the molecular weight of the cation source in an uncharged state is 31 or greater and the Henry's law constant of each of the anion source and cation source is 1.0 x 10 4 (Pa/mol·fraction) or greater in a standard state. |