The objective of this project is to clean geothermal water before discharging it to underground and also extraction of energy created by mixing of effluents with various salinities. Geothermal fluids may contain high levels of such toxic elements as arsenic, mercury, lead, cadmium, iron, zinc, manganese and boron. If the used brine is released into surface aquifires, these elements can damage aquatic life. For this reason, the partners have developed several methods, based on the sorption-membrane filtration method as well as RED and CAPMIX methods for the elimitation of toxic elements and harvesting the energy from salinity gradient, respectively.