Qualidade da água do Rio Poti na região da Grande Teresina – PI.

Abstract

The present study aimed to monitor and evaluate the water quality of the Poti River, an important water source in Greater Teresina, Piauí state, according to CONAMA legislation and its suitability for various uses, especially in agro-industry, to understand its current conditions and possible impacts, providing data to competent agencies for the conservation and rational use of this resource. To this end, physical-chemical and biological analyses of water collected at four different locations along the river were performed: under the Wall Ferraz Bridge, Juscelino Kubitschek Bridge, Primavera Bridge, and Poti Velho Bridge. The analyzed variables were pH, turbidity (NTU), electrical conductivity (dS.m-1), and chemical oxygen demand (COD) (mg/L). According to the findings, using Resolution No. 357/2005 of the National Environmental Council (CONAMA) as a parameter, although the results meet the standards of the aforementioned resolution, there is a significant change in BOD and nitrate levels, indicating greater pollution during the non-rainy season due to the decrease in Poti River flow. This has a negative impact on water quality and can lead to excessive development of aquatic plants, such as water hyacinth, during drier periods. However, it can be concluded that a proper continuous study of water balance will enable analysis of water availability and its management, and verify the correct application of hydrological models and understanding of the relationships between stored water and its flows.