Qualidade de águas subterrâneas em área do sertão central do Ceará com base em índices iônicos

Abstract

Water resources are strategic elements for the development of societies, their use and management must be done effectively and efficiently, mainly in semiarid regions, which present natural conditions unfavorable to access to water. It is common in these regions to increasingly exploit groundwater, however, their rampant use represents threat in quantitative and qualitative terms to aquifers. Salinization of water and soil, industrial scale, corrosion and health hazards are understood as consequences relevant to poor groundwater quality. Therefore, it is essential to establishment of quality standards and profiles for them, such as support systems decision-making and management of groundwater resources. In this In this context, the analysis of groundwater quality (under alluvium) from the region of Banabuiú, Quixeramobim and Quixadá from the point of potential risk to salinization, corrosion and fouling by means of diagrams chemicals and water quality indices. Results showed differences in content between the waters under crystalline basement and those in alluvium. Juatama wells, which have the lowest constituent load chemicals among all waters analyzed. According to Piper's diagram, predominate chlorinated sodium or mixed waters. The three mechanisms proposed by Gibbs act on the chemical composition of the studied substrate waters. There was a convergence of stability index results, indicating a strong trend towards corrosive water, even in wells with low ionic charge. The indices and Ionic reasons for irrigation showed a higher risk of salinization than soil sodification, but it cannot be discarded. There is low probability precipitation of the harmful carbonate salts and good suitability of the waters as the risk of reduced soil permeability. The water quality indexes referring to ionic content indicated medium and high restriction waters. Strong were obtained correlations between the indices applied in the study. The importance of the evaluation is of the ionic content of the semiarid groundwater through descriptive indices of as these are tools to assist in the management of such resources, indicating restrictions of use and, consequently, corrective actions.