Razões iônicas e índices de Langelier e Larson no estudo hidrogeoquímico das águas subterrâneas no município de Quixeré - Ceará

Abstract

The Apodi Plateau houses the second largest groundwater resources of Ceará State, being used for irrigation; the township of Quixeré, with part of its área on the Plateau, is one of the greatest producers of melons of the State. As groundwaters of the area come from limestone aquifers and present elevated hardness, we used Langelier index for a diagnosis of calcarious deposition capacity, Larson index to avaluate natural aggressiveness of the water, and íon ratios to study its hydrochemical behavior. For the determination of these indexes and ratios, hydrochemical analyses were made on 31 samples taken during the rainy season and 29 during the dry one. Results show that all wells produce fresh water, in the majority of samples, marked by dolomite dissolution and presenting tendency to precipitation.