Geoquímica de las aguas subterráneas y procesos de ablandamiento natural en áreas kársticas

Resumen

Water emerging at karstic springs contains high concentrations of hardness caused by thedissolution of carbonated geologic formations. This characteristic limits its use in aquaculture, especiallyin commercial production of freshwater prawn. In this paper, a combined approach of geochemical andnatural softening processes was adopted to assesss the factors controlling the water hardness in karstareas. Along the direction of flow hydrochemical trends are seen as the water type changes from Ca-HCO3 to Ca-Mg-Cl, at the same time enrichment in some ions derived from the dissolution of minerals ofthe substratum. In this way, almost 60% of the water samples were oversaturated in calcite. At waterfalls,it can be discerned that these effects are caused by two physical changes of water flow_ the waterturbulence and the increase of the air ater interface, increasing the pH and producing reduction of waterhardness. It is suggested that further investigation for predicting the reaction rate should focus on thereaction rates at the air-water interface and the critical degree of supersaturation.