Estudo analitico da dureza e alcalinidade de águas de abastecimento visando abrandamento por meio de resina de troca iônica.

Abstract

The City Cuite is supplied by water from the dam Boqueirao Cais, however the water supplied population has shown higher values of hardness, the levels found indicate that water has a rating of hard due CaC03 concentration. This study aimed to quantify the level of water hardness and alkalinity supply in the city Cuite considering the influences of different stations and treatment process conducted by CAGEPA, and develop analytical methods for the improving the feasibility of determining water hardness by complexometric titration and conductometric analysis. The sampling procedure involved samples collected from different parts of the city as residences (points C and D), University (A, B and H) and CAGEPA (E), and samples of primary source "raw" (points F and G) in the period November 2010 to April 2011. Three samples were collected from each point. The samples were stored in polyethylene bottles for later analysis. The major tests realized were of pH, conductivity, classical methods (titutometria complexation / neutralization). New methodologies using ion exchange resins were performed. The pH values ranged from 7.05 to 8.17 points F and G due to concentrations of CaC03 incorporated in the soil of the dam. Boiled water samples showed high levels of conductivity, hardness and pH values due to precipitation of salts dissolved in water and consequently increases the ionic strength. All samples are within established standards by decree No. 518/04 of the Ministry of Health. The process of softening using ion-exchange resin was efficient, with effluent hardness close to zero. This methodology provides an alternative for improving water quality in the city.