Scholarly record
HYDROCHEMICAL AND ISOTOPIC CHARACTERIZATION OF WATER RESOURCES IN A MINING-IMPACTED REGION OF SOUTHERN ECUADOR
Abstract
Mining activities can significantly affect water resources by altering their chemical composition and promoting the mobilization of contaminants in aquatic systems. In this context, this study analyzed the hydrochemical and isotopic characteristics of hydric resources in a mining-impacted region of southern Ecuador in order to identify the main processes controlling water chemistry, determine the origin, and identify potential sources of contamination. Eighteen water samples were collected (10 surface water and 8 groundwater) and evaluated through the analysis of major ions (Ca, Mg2, K, Na, HCO3, SO42, Cl, NO3), and environmental isotopes (18O, 2H, 3H, 14C, 34S SO42, and 18O SO42). The dataset was interpreted using hydrochemical diagrams and geospatial analysis to identify the spatial distribution patterns and the main factors controlling water composition. The results indicated that 70% of surface waters were calcium–sulfate facies, while the remaining as calcium–bicarbonate type. Groundwater samples were predominantly calcium–bicarbonate type. Precipitation was identified as the primary source of hydric recharge using stable isotopes. In addition, the isotope composition reflects a clear altitude effect. Sulfate in surface waters is mainly derived from the oxidation of sulfur-bearing minerals like pyrite; however, groundwater samples exhibit a more diverse range of sulfate sources, including possible contributions from sewage. The tritio isotopes indicates predominantly modern groundwater, suggesting short residence times. This research provides comprehensive hydrochemical and isotopic characterization, contributes valuable baseline information for the sustainable management of these resources and support the development of strategies aimed at protecting water quality in regions affected by mining activities.
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References11
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