Evaluation of the water quality of the Caititu River in the municipality of Lábrea - AM

Abstract

The share of fresh water available in watercourses is minimal, and this is the main source for use in various purposes, in addition, its quality can be affected mainly due to anthropogenic actions. In view of the above, the present study aimed to evaluate the water quality of the Caititu River, in the municipality of Lábrea-AM, applying the calculation of the water quality index (WQI), adapted by the Environmental Company of the State of São Paulo-CETESB. The study was conducted at four points along the river in June 2022, corresponding to the dry period of the region. The physical (Temperature, Turbidity, Total Dissolved Solids), chemical (Dissolved Oxygen, BOD, Total Phosphorus, Total Nitrogen, pH) and microbiological (Thermotolerant Coliforms, Total Coliforms) parameters were analyzed for the application of the WQI and comparison with the limits recommended by CONAMA Resolution No. 357/05. The variables dissolved oxygen (P3) and total phosphorus (P1, P2, P3, P4) diverged with the resolution. The values of the WQIs were consistent with the indices analyzed during the research, representing well the waters of the Caititu River, with a “good” classification range for all points, reflecting the capacity of self-purification of pollutants that the river exerts during the dry period.