Hydrochemistry of carbonate and bicarbonate: effect on groundwater quality in Crateús, Ceará, Brazil

Abstract

The city of Crateús is located in the semi-arid region of northeastern Brazil, where climatic conditions cause water scarcity and low quality of available water. This work was a one year study of the behavior of pH and concentrations of carbonate (CO32-) and bicarbonate (HCO3-) ions in the waters of eight wells used for irrigation of small crops and domestic consumption. The results showed that none of the samples had pH values that compromised their quality, both for use in irrigation and for human consumption. However, carbonate and bicarbonate ions presented restrictions that varied from mild to severe. Therefore, its use in agriculture requires rigorous monitoring and care to mitigate the negative effects on productivity and soil.