Análise da qualidade da água do Cacimbão na zona sul de Bagé

Abstract

Water is essential for the life of all living beings. The potable water must comply with the specified parameters by the Potability Legislation, Ordinance 888/2021 of the Ministry of Health. Aquifers are underground reservoirs of rainwater, which undergoes a natural filtration as it percolates through the cracks in the soil surface, and so they are pointed out as a good option for the lack of water in the world. Bagé is a city with drought history, which consequently led its inhabitants to live with restrictions on the regular water network consumption in times of severe water scarcity, this situation encourages the population to look for alternatives on the water supply. For the above mentioned, the objective of this Course Completion Work was to characterize the water quality of Cacimbão, which is a natural water source that originates from groundwater, located in the south of Bagé, researching the presence of contaminating agents in the water, and to propose an adequate previous treatment for its safe consumption by the community. The methodology consisted of collecting 5 Cacimbão's water samples and 1 sample in a house close to it, in which the water distribution originates from the regular city water network, and at analyzing the physicochemical and microbiological elements of these waters. Through the analysis were obtained the values of pH, turbidity, electric conductivity, total dissolved solids, salinity, dissolved oxygen, water hardness, and total and thermotolerant coliforms. The pH stayed around 7 and turbidity obtained a result of 0.33 NTU. The electric conductivity showed an average value of 310.5 μS/cm, the analysis of total dissolved solids had 155.2 ppm and salinity stayed around 7‰. The dissolved oxygen analysis had as result 7.3 ppm, for water hardness it showed 159.5 mg/L of CaCO3. The microbiological analysis detected the presence of total coliforms and Escherichia coli in all of the samples collected at Cacimbão, and the absence of these parameters in the water collected at the house nearby. Therefore, Cacimbão's water is accorded to the physicochemical parameters required by legislation (except for electric conductivity), being classified as potable water, brackish class 1. For the microbiological parameters, the water turned out as non-potable. Two technical disinfection solutions for previous treatment of the water were proposed: boil and addition of chlorine, only the last one showed promising results.