Evaluación de la presencia y distribución de los metales pesados cromo, níquel y plomo en el río Ocoa, en la zona comprendida entre la desembocadura del caño Maizaro hasta el puente Murujuy, municipio de Villavicencio - Meta

Abstract

The objective of this work is to evaluate the concentration, distribution and relationship with environmental variables of the heavy metals Chromium, Nickel and Lead in the Ocoa River, located in the municipality of Villavicencio in the department of Meta, in a stretch of approximately 25 km in the area between the mouth of the Maizaro Canal and the Murujuy Bridge. To this end, two samplings were established at a time with high levels of precipitation (> 400 mm) and two more at a time with low levels of precipitation (<100 mm). The variables that were measured in the field were temperature, pH, conductivity and dissolved oxygen, the quantification of heavy metals was performed in a laboratory certified by the IDEAM based on the flame atomic absorption spectrophotometry technique. The maximum concentrations of the 3 metals studied (0.063 mgCr/l - 0.019 mgNi/l - 0.049mgPb/l) were above the permissible limits established by Decree 1594 of 1984, Chromium and Lead exceeded the reference values of Resolution 2115 of 2007 and OMS; particularly the Lead exceeded the maximum concentration limit indicated by the EPA. Significant correlations were found (p <0.05) between the presence of lead and temperature, pH and conductivity. The concentrations of the metals were spatially represented by distribution maps and, in conjunction with the results, recommendations were made to environmental entities in order to address the problem of heavy metal contamination at the regional level.