Forward Osmosis is a very ...

Forward Osmosis is a very useful technique in water recovery from mine tailings, and can be used in other applications to concentration a solution to some desirable value.  FO membranes are more robust (thicker) than RO membranes, and can generally take considerably more "abuse".

The FO has been utilized for field water purification for troops where the draw solution is concentrated sugar, and so the soldier gets a hydration aliquot with also some instant energy from the sugar.

FO could be applied with low grade waste heat on the spent draw solution where thermolytic salt such a ammonium bicarbonate is used.  Heat at 45-60 degree C is sufficient to break the salt down to ammonia and carbon dioxide in the head space above the recovered water, thus producing relatively pure water from swamp water, sewage, bilge water, river water, etc.