Water quality index (WQI) and balneability in freshwater beaches on the Negro River, Manaus (Amazonas)

• Autor(a) principal: Arcos, Adriano Nobre
• Data de Publicação: 2022
• Outros Autores: Cunha, Hillândia Brandão da
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Revista Espinhaço
• Texto Completo: https://revistas.ufvjm.edu.br/revista-espinhaco/article/view/196
• topic: contaminação; potabilidade; recreação; recursos hídricos; contamination; potability; recreation

Many aquatic environments have been impacted by urbanization and lack of sanitation, directly affecting the environmental quality of these environments. Therefore, the objective of the study was to evaluate the water quality index (WQI) and the bathing suitability of the tupé, lua, and ponta negra beaches, located in the Negro River in Manaus. Samples were collected from three beaches during the two seasonal periods (flood and dry) in 2008, processed, and analyzed. The WQI was calculated by the weighted product of the quality value of each of the nine parameters evaluated: sample temperature, pH, dissolved oxygen, biochemical oxygen demand, thermotolerant coliforms, total nitrogen, total phosphorus, total residue, and turbidity, with their respective weights fixed according to their importance for the overall conformation of the water quality. The bathing conditions followed the standards and criteria determined by the National Environment Council Resolution, classifying the water as suitable and unsuitable according to the density of fecal coliforms present. The bathing conditions for tupé and lua beaches were classified as suitable in both seasonal periods, and ponta negra beach was classified as unsuitable for bathing in the dry period of the Negro River. The WQI of the beaches varied between excellent and good, presenting a gradient of decrease in water quality as the city of Manaus approached. The population and the inspection agencies should be aware of the bathing conditions of the waters of these beaches, so that measures can be taken to combat the entry of potential polluting sources.