On Recovery Opportunity for Critical Elements from Effluent Water from Mining, Oil, Natural Gas, and Geothermal Operations in Poland

We present the first comprehensive study on effluent water from mining, oil, natural gas, and geothermal operations in Poland. In 2019, we explored chemical composition of effluent samples collected from 67 locations in Poland representing various oil and gas, mining, and geothermal operations. It has been found that the effluents contained large amount of various elements. Those elements are critical and indispensable for the European Union industry and renewable energy technologies. Thus, the recovery opportunity of critical elements from the effluent water was discussed. We highlighted the main needs and directions for further development of desalination technologies for effluent water. The majority of the analyzed water samples were characterized by high concentration levels of total dissolved solids in the range from 5 to 150 g/L. The highest concentrations of elements in investigated water samples, from several tens to hundreds of mg/L, were observed for K, Mg, Br, Ba, B, Mn, Li, SiO 2 , and Sr. Additionally, most of the mine and geothermal water samples contained several tens of g/L NaCl. The most valuable element found in the investigated water samples was lithium. Desalted fresh water can be reused in agriculture or industry. Thus, desalination and extraction of critical elements from effluent water is a sustainable solution to the water scarcity problem in Poland caused by climate warming as well as a means to strengthen resilience of the resources supply for agriculture, industry, and renewable energy technologies.