The concept of multivariant use of geothermal water concentrates

Geothermal waters usually contain elevated concentrations of specific elements, which could be valuable for reuse. The hydrogeochemical composition of recovered concentrates strictly determines potential management and reuse for other purposes, including balneology sector. Natural water, which possesses curative parameters, can be concentrated by use membrane processes to produce curative solutions or crystalline salts used for healing baths or inhalations. Concentrates can be a valuable resource for production of mineral salts, metals, valuable chemicals, and also magnesium, calcium, potassium, and sodium salts or other products for cosmetology and balneology industry. The aim of this work was to present the results of the assay oriented toward examination of the potential further multivariant use of concentrates gained in two-stages of NF-RO (nanofiltration–reverse osmosis) treatment system of geothermal waters. The assessment of the possibility of domestic use of concentrates gained as a therapeutic product, for example, in health baths, required the assessment in order to meet the requirements of the local regulations. The study results revealed that concentrates gained from two-step NF-RO system, due to the concentration of the desired ingredients, were a potential source of different valuable mineral solutions, because of high content of sodium, magnesium, chlorides, silica, and other components used for therapeutic purposes.