The use of membrane technology, both in wastewater treatment and in the production of drinking and process water, has expanded enormously in recent decades. Membrane techniques, however, do not offer a complete solution, because of a residual product that remains by means of a saline concentrate stream (brine). GaLiCos is a maintenance-free technology, that can be used to concentrate brine above the saturation limit, using residual energy. When a combination of a GaLiCos evaporator/condenser is used, a high quality water can be produced out of a wastewater stream, suitable for re-use.