Analysis of water quality and trophic state in a reservoir of the Potengi River Basin, semi-arid region of the Northeast

Abstract

Water is an essential natural resource for sustaining life on the planet. However, the unsustainable use of this resource, especially due to accelerated demographic growth and the intensification of human activities, has caused scarcity the loss in its quality . In this context, the aim of this study was to evaluate the physical-chemical and biological parameters, the water quality, and the Trophic State Index (TSI) of Barragem Campo Grande/RN. The evaluated parameters were dissolved oxygen (DO), pH, turbidity, biochemical oxygen demand (DBO), ammoniacal nitrogen, total phosphorus, total solids, water temperature, chlorophyll-a, Escherichia coli and phytoplankton. The information on the reservoirs parameters was obtained through secondary data, made available by the QUALIÁGUA Program, which conducted the reservoir monitoring , between 2018 and 2019. The parameters that failed to meet the by CONAMA resolution 357/2005 class 2 water bodies recommended limits were the variables DBO, total phosphorus and E. coli. The monitoring data showed a higher IET for the rainy period, categorized with a Hypereutrophic mean, while the dry period was categorized with a Eutrophic index.