Hydrographic Basins in the City of Manaus, Amazonas, Brazil: Monitoring of the Water Quality in the São Raimundo Basin Between 2020 and 2021

• Published in: Water, air, and soil pollution Vol. 235; no. 3; p. 191
• Main Authors: Duvoisin, Sergio, Albuquerque, Patrícia Melchionna, dos Banhos, Elissandro Fonseca, Oliveira, Rafael Lopes e, Batista, Carla Estefani, Ribeiro, Igor Oliveira, de Loiola, Sara Kethleen Soares, Neta, Aleyde Sales Corrêa, Moraes, Claudia Rosa Figueiredo
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.03.2024; Springer Nature B.V
• Subjects: Atmospheric Protection/Air Quality Control/Air Pollution; Biochemical oxygen demand; Cities; Climate Change/Climate Change Impacts; Coliforms; Developing countries; Dissolved oxygen; Earth and Environmental Science; Effluents; Environment; Evaluation; Hydrogeology; Industrial effluents; Industrial wastes; Industrial wastewater; LDCs; Monitoring; Oxygen requirement; Parameters; Phosphorus; Pollution; Public policy; Sewers; Soil Science & Conservation; Surface water; Total oxygen demand; Turbidity; Variance analysis; Water monitoring; Water quality; Water Quality/Water Pollution; Brazil; Manaus; Amazonas; São Raimundo basin; WQI; Water quality
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-024-06990-0

In developing countries, such as Brazil, public policies for monitoring surface water quality are precarious. Although the country has legal norms that establish water quality parameters, and the Water Quality Index (WQI) is used as an assessment tool, the management of surface water is neglected in cities such as Manaus. The objective of this study was to evaluate the water quality of the São Raimundo basin in Manaus during the years 2020 and 2021. The following parameters were evaluated: dissolved oxygen (DO), thermotolerant coliforms (Colif), biochemical oxygen demand (BOD), pH, temperature (Temp), total nitrogen (Ntotal), total phosphorus (Ptotal), turbidity (Turb), and total solids (Sol.T). ANOVA showed that the water quality is constantly low, and in no period of either year did it present acceptable levels for use. The Colif result having a mean value of 96.7 × 10 3 NMP 100 mL −1 in the month of February 2020. October 2020 and 2021 presented the worst results for the WQI with values of 27.7 and 28.2, respectively. Multiple regression showed DO, Turb, BOD, and Ntotal as being the most significant parameters, which indicates that the pollution probably originates from sewers and industrial effluents. This is the first study to monitor the waters of the São Raimundo basin using this approach. The results show the need for urgent treatment of the water in the basin via environmental preservation and recovery measures. This type of study could thus result in changes in the management of the water in this basin as well as in similar ones present in the Amazon region.