Hidrogeoquímica do aqüífero caiuá no estado do Paraná

Abstract

The groundwater from the northwestern region of the Paraná state, collected by tubular wells has been used as water supply to many cities (figura 1). So it is necessary to evaluate the groundwater quality from the Caiuá aquifer in this State (figura 2). A survey of 168 tubular wells of the northwestern region of Paraná state was carried out in order to determine the main chemical characteristics of these waters with the objective of relating the trend of the chemical conditions of this aquifer. By means of the Piper diagram with the waters of the Caiuá aquifer, the bicarbonated-calcic and calcic-magnesic characteristics were maintained, with a relatively diffuse distribution (figura 3). This composition, in great part less mineralized than the basalts of Serra Geral formation, agrees with the chemical typology for waters of this aquifer in the Paraná Basin (figura 4). Map of plotted wells with Stiff diagrams (figura 5) shows the chemical composition ranges and suggests a compatible relationship to the geologic features. Figures 6 to 16 show the distribution of the amounts of Na+, Ca2+, Mg2+, K+, Cl-, HCO3-, NO2, SO32-, silica, pH and TDS, respectively.