Qualidade da água no rio Palomas e rio Azul no município de Barra do Rio Azul - RS

Abstract

The water quality results from natural phenomena and mainly from human activities, reflecting the use and occupation of soil in the river basin. Based on this, this work aimed to evaluate the quality of the waters of the Palomas river and Azul river, in the municipality of Barra do Rio Azul - RS. Four collections were carried out in the months of January, March, May, and August 2023 and the analyzes were carried out in the laboratories of the Environmental Science and Technology Center (ESCT) of the Federal University of Pampa (Unipampa), Campus Caçapava do Sul. The water samples at 5 points, with point 1 (PT1) being located at the meeting of the Palomas and Azul rivers, point 2 (PT2) and point 4 (PT4) are located on the Palomas river, point 3 (PT3) is located on the Azul River and point 5 (PT5) on the water intake dam on the Palomas River. The following parameters were analyzed for the purposes of the water quality index (WQI): temperature, pH, dissolved oxygen, turbidity, total solids, biological oxygen demand, thermotolerant coliforms, nitrate and total phosphorus. The following parameters were also analyzed: total coliforms, electrical conductivity, color, alkalinity, hardness and iron to complement the assessment of water quality. Based on the WQI analysis, PT1 was classified as poor and points PT2, PT3, PT4 and PT5 presented a WQI classified as reasonable. Through complementary analyzes it was found that these waters fall into classes 1 or 2, however, due to the results of the bacteriological analyzes, the waters ended up falling into classes 2, 3, or 4 as established in CONAMA Resolution 357/2005. This work made it possible to evaluate the water quality of these rivers, highlight critical points and classify the waters in accordance with current legislation, highlighting the influence of the population on the quality of the waters studied.