Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8865981 | Journal of Geochemical Exploration | 2018 | 39 Pages |
Abstract
The composition of groundwater primarily reflects hosting lithologies, and according to other studies, natural bottled water can be used as a simple means of groundwater sampling. This study aims to establish compositional relations between the groundwater of six aquifers of São Paulo state, Brazil and host igneous, metamorphic and sedimentary silicate rocks. Bottled water drawn from sixty-eight different sources was analyzed to apply a source-rock deduction. One-fourth of the bottled water was resampled to determine the concentration of rare earth elements (REE). The mineralization of the water is low (TDSâ¯=â¯7-332â¯mg/L, medianâ¯=â¯79â¯mg/L), its pH is mostly circumneutral and the hydrogeochemical characteristics of the majority of samples indicates Na-Ca-HCO3 type. Silicate weathering (possibly of plagioclase), is the main mineralization process identified for all six aquifers. Minor processes identified include the weathering of gypsum and ferromagnesian minerals and cation exchange. From the REE content we split the set of samples into two subgroups. The subset with higher âREE (529-10,932â¯ng/L) is acidic (pHâ¯<â¯6) and includes less mineralized water from shallow sources. A second set is compositionally more heterogeneous and grouped samples with lower âREE values (0.67-100â¯ng/L). Concerning regulated constituents, only two specimens present either high U (98â¯Î¼g/L) or Cr (73â¯Î¼g/L) values. Twenty-three samples show nitrate values (NO3-Nâ¯>â¯0.7 up to 9.0â¯mg/L) that are attributed to non-lithological sources. Overall, these results indicate that the sampled bottled mineral water satisfactorily represents the groundwater in corresponding aquifers.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Economic Geology
Authors
Isabella Longhi Bulia, Jacinta Enzweiler,