Análise da influência do uso do sulfato de alumínio na otimização do processo de tratamento de água na ETA do Distrito Piau em Piranhas – AL

Abstract

Water for human consumption must meet the potability standards established by Ordinance No. 888, MS/MG of 2021, so it is the function of the Water Treatment Stations (ETA) to ensure that the consumer has access to drinking water and avoid losses their health. The first stage of this work consists of a study of coagulation and flocculation based on bench

tests with the aid of equipment consisting of a jar test for the evaluation of the physical- chemical parameters pH, turbidity and apparent color in the comparison between raw water

and after using aluminum sulfate Al2(SO4)143H2O, developed in the laboratory of the Water Treatment Station of the Piau District, in the city of Piranhas - AL, located in the high hinterland of Alagoas, in order to obtain the “optimal” dosage ” from coagulant to the treatment system. Different dosages of coagulant were chosen and added to each jar and obtained from a 60 ml/L solution of Al2(SO4)143H2O in raw water. All samples with aluminum sulfate were within the limit established by law and the best sample was that of jar 3, with 1 ml of sulfate dissolved in 2L of water, resulting in the optimal dosage as it presented a value closer to the “optimal pH”, less turbidity and color. The second stage of the study comprises the comparison of raw water parameters and water with Al2(SO4)143H2O on a real scale in the ETA treatment system, using the optimal coagulant dosage defined in the previous test, samples of treated water were collected in different stages of the process, before and after the addition of aluminum sulfate. The results showed a significant improvement in the removal of 82% of the color and 91.62% of the turbidity and pH stabilization in 1.87%, after the addition of the chemical product. In addition, the use of aluminum sulfate combined with direct filtration allowed a reduction in the use of chlorine in disinfection, optimizing the water treatment process at the Sertão Alagoano ETA. It is concluded that the addition of aluminum sulfate is an effective and viable alternative for optimizing the water treatment process for this water station and for other similar ones.