Evaluación de la calidad del agua y determinación de metales pesados en sedimentos de la microcuenca del río Alajua

Abstract

This study aims to evaluate the quality of surface water and determine the heavy metals in the sediments of the Alajua River micro watershed through the analysis of physicochemical and microbiological parameters. Consequently, it made a sampling campaign and determined five points in the high and low watersheds of the river. The results obtained from characterizing the water and sediment samples were analyzed with the maximum allowable limits set by Ecuadorian environmental legislation (TULSMA). In addition, parameters such as pH and conductivity are monitored at all test points, turbidity, sulfates, and nitrates in the water test, and metals in water sediments did not exceed the following limits: Al, Cd, Cr, As, and Ni. However, high concentrations of Mn, Fe, Cu, and Pb were found in the upper and lower watershed, exceeding the TULSMA limits. The results of the microbiological analysis showed total and fecal contamination at all points. The most polluted points were point 3 (200 meters below the Pungoloma-Quisapincha road), point 4, and point 5, located in the Aguaján sector. Two water quality indices, NSF and Dinius, were calculated from the data collected. The assessment of the water quality in the river with the two water indicators indicated the three points mentioned earlier to be suitable for human beings and acceptable for agricultural irrigation. In conclusion, the continuous monitoring of this micro-watershed should be constant.