Análise da qualidade das águas em uma lagoa na zona urbana de Russas-CE

Abstract

Water bodies located in urban environments suffer greater pressure in the diversity of their uses, as well as being affected by the pollution generated in cities. Those located in the semi-arid region of the Brazilian Northeast also face the water deficit caused by the disparity between rainfall and evaporation rates. In this sense, this study aimed to analyze the water quality of Lagoa da Caiçara, located in the urban area of the municipality of Russas - CE. The research was carried out with water collections at two sampling points during the dry season, between August and December 2021. Physicochemical parameters of pH, electrical conductivity, total residue, total dissolved solids, turbidity, total alkalinity, chlorides and total hardness were analyzed, in addition to the microbiological parameters of total coliforms and E. coli, in order to evaluate the classification class of the waters of the Lagoon and the possible indication of fecal contamination. Among the physicochemical parameters, the values of total dissolved solids, pH, turbidity and chlorides were above the framework value of Conama Resolution No. 357/05, the latter having presented values between 414.77 and 1013.87 mg/L Cl. The analysis of total residue, total hardness and electrical conductivity showed values above the normality of ecosystems, especially electrical conductivity, with values up to 3030 μS/cm. Finally, the total alkalinity was within the acceptable range. In the microbiological analysis, the presence of total coliforms and E. coli was detected during the monitoring period. Thus, the waters of Lagoa da Caiçara may be degraded and, therefore, should not be recommended for recreational use or for fish consumption.