Hydrochemical Behaviour Of Dissolved Uranium In Selected Groundwaters Of The Klodzko Valley (Sw Poland) And Its Application Possibilities As An Environmental Tracer

Waters from the Klodzko Valley containing pharmacodynamics therapeutic agents are used for drinking and for balneotherapeutical purposes. These medicinal, highly mineralized waters are mostly of deep circulation. Moreover, outflowing water contain admixture of shallow circulation water of contemporary infiltration which negatively effects medicinal water quality. Due to the complicated pathways of groundwater circulation, the authors used uranium as an environmental indicator to gain deeper insight into the factors affecting the quality of exploited medicinal water and groundwater origin. The authors collected samples from 26 groundwater intakes from 3 Spas and from one mineral water bottling plant U-234(,)238 and U-234/U-238 for analysis of activity ratios using alpha-spectrometry technique. Uranium was applied as a dilution tracer of medicinal mineral groundwater by shallow circulation low-mineralized water. The results of U-234/U-238 activity ratios in particular water intakes collected in different years were equal in the range of uncertainties although the uranium concentrations varied. The stability U-234/U-238 activity ratio parameter is a consequence of dilution of medicinal water by shallow circulation water of present infiltration with a very small amount or without uranium. Apart from simple water dilution, waters of deep circulation mixed with low mineralized shallow circulation water may also contain an admixture of third deeper circulation component with different both U content and U-234/U-238 ratio. In that case U-234/U-238 ratio may be applied as a hydrogeochemical tracer. (C) 2020 Elsevier Ltd. All rights reserved.