Análise da qualidade da água de nascentes da Microbacia Hidrográfica do Arroio Encantado no município de Cerro Largo/RS

Abstract

The importance of springs for the formation of water bodies that will serve as a source of human supply is indispensable. Linked to this, there are natural environmental impacts and those that end up being caused by human interference, which contributes to accelerating this scarcity. In order to understand these problems, this study will identify and analyze the water quality found at the sources of the Arroio Encantado hydrographic microbasin in the municipality of Cerro Largo, Rio Grande do Sul. During the investigations carried out at the site and the factors that contribute to the degradation of these springs, the following physical-chemical and bacteriological analyzes were carried out, such as apparent and true color, turbidity, conductivity, total solids, temperature, pH, total nitrogen, dissolved oxygen, total phosphorus and total coliforms. The collections at the springs occurred during the flood and dry season (spring and summer), with their locations obtained using GNSS trackers and field campaigns. The calculation of the Water Quality Index (WQI) was performed from the determination of seven parameters such as dissolved oxygen (DO), pH, temperature, total solids, total nitrogen, turbidity and total phosphorus. Finally, some parameters were compared with CONAMA Resolution 357/2005, since there are parameters that are not covered by CONAMA 357/2005. The results for the WQI of the springs of the Arroio Encantado hydrographic microbasin were classified as “acceptable”, it is worth mentioning that during the second collection two springs found no flow due to the drought in the municipality. For future work, it was suggested to determine the parameters Thermotolerant Coliforms and Biochemical Oxygen Demand (BOD), as the WQI classification could be changed. The total phosphorus parameter, used for the calculation of the IQA, presented concentrations above the limit allowed by CONAMA Resolution 357/2005 for class 1. Through the results, the current situation of the sources of the Arroio Encantado can be observed.