Determinación de surfactantes aniónicos en la microcuenca del río Pachanlica

Abstract

Ecuador's river systems are subjected to daily discharges of large amounts of pollutants due to industrial and domestic activities. A common issue is the presence of anionic surfactants. This is widely used in various industries, which deteriorate water quality due to their properties such as emulsifying, detergent, and foaming characteristics. This situation is exacerbated by the lack of resource control and characterization. Therefore, the objective of this study was to evaluate contamination by anionic surfactants in the Pachanlica River micro-basin. Using a descriptive methodology, samples were collected along the transect, enabling the analysis of 14 points to estimate the concentration of anionic surfactants (mg/L) using the TNT 874 method. Additionally, the study focused on determining the content of anionic surfactants in the water of the Pachanlica River micro-basin, providing data to assess its vulnerability to contamination by xenobiotics. For the biological assay, lettuce seeds (Lactuca sativa L.) were moistened with river water used for irrigation in the area under controlled conditions for three days to observe germination variation. The results indicated that the points with the highest concentrations were CP-005 and CP-006 in Cevallos-Quero area with 4.25 mg/L and 2.92 mg/L respectively, and CP-008 in the Totoras-Salasaca area with 0.535 mg/L. In vulnerable zones, the germination index was 0%, while at point CP-011 in the Picaigua-Salasaca area (0.293 mg/L). The germination index was 116.23%. The study concluded that the biological assay results revealed that water from the Pachanlica River micro-basin at the three points analyzed does not meet the criteria for safe irrigation use.