Evaluación del comportamiento del aluminio en suelos de sistemas lacustres y valles periglaciares de las microcuencas de Atillo y Ozogoche

Abstract

The current research, authorized by the GIDAC, evaluates the behavior of interchangeable aluminum (Al+3) in the soils of lake systems as well as periglacial valleys of Atillo and Ozogoche micro-basins located in Chimborazo. One hundred soil samples were analyzed through Atomic Absorption Spectroscopy (A.A.S.), using the aluminum (AI) hollow-cathode lamp - Thermo Fisher Scientific equipment with a nitrous oxide-acetylene flame. The toxicological bioassay is carried out in triplicate using the Lactuca sativa L. biomarker, which evaluates its behavior at different aluminum concentrations. In addition, an analysis on the coefficient correlation between the concentration of Al+3 and the humidity, pH, organic matter (OM), organic carbon (CO), electrical conductivity (EC) and cation exchange capacity (CEC) factors is carried out. Finally, the geo- accumulation index formula and the enrichment factor are applied and assessed to know the value and contamination source of Al+3 in these soils. The Al+3 average concentration is 1.74 ppm; where three quartiles were identified: Q1=0.39, Q2=1 and Q3=1.84, these allowed to identify the distribution of this element in the study area. The toxicological bioassay determines the minimum and maximum GI of Lactuca sativa L. biomarker (0. 33 and 88.54%, respectively); and the median lethal dose (LD50) at 20.42 ppm. The concentration of Al+3 in this area is generally low compared to other soils with similar characteristics and with a high degree of variability due to the characteristics of the area. However, some areas with high concentrations regarding the general behavior of Al+3 were found in these micro-basins; so, it is recommended to carry out studies in the areas where these anomalous values were found in order to identify the factors that cause this behavior.