Avaliação da presença de dióxido de carbono em águas subterrâneas e sua influência no processo de corrosão

Abstract

The Northeastern population makes use of groundwater due to the difficulty in obtaining water from Treatment Plants and the scarcity of water in the main reservoirs due to the droughts of the last decade. However, when using this water, care should be taken, as various contaminants may be present in it. One of these contaminants is Carbon Dioxide (CO2), which can make the water unhealthy and cause corrosion of the well piping more quickly. In addition, the presence of this oxide can also cause incrustations in the pipes, which generates a high maintenance cost. Other factors that can interfere with water potability are pH, Total Iron and Total Alkalinity. Based on this problem, the objective of this work is to verify the corrosion potential of groundwater using the parameters mentioned in three municipalities in the state of Ceará. To determine these parameters, the procedures referred to in the Standard Methods for the Examination of Water and Wasterwater were used. According to the results, it was found that most waters have a considerable potential for corrosion. In addition, with reference to the maximum values allowed by the PRC Ordinances Nº. 5/2017, by CONAMA Resolution Nº. 396/2008 and by the cited literature, most of the values are within the established ranges. However, a sample from municipality C (C5) had a CO2 content of 3821.5 mg /L and a pH of 5.19. This result raises an alert regarding the need to pre-treat this water to remove CO2, leaving it for human consumption.