Evaluación de la remoción de arsénico desde medios acuosos por adsorción sobre arena recubierta con óxidos de hierro naturales.

Abstract

The purpose of this research was to remove arsenic present in aqueous media by using sand coated with natural iron oxides by adsorption. The andosol was screened and extracted in the Francisco de Orellana Precinct, which belongs to the Province of Santo Domingo de los Tsáchilas, to separate the fine sand fraction corresponding to the interval between 50 - 100 um, where the natural iron oxides. With the help of an Infrared Spectrophotometer (Infrared Spectrometer), the respective characterization of the andosol soil containing natural iron oxides was carried out. With an EDX detector coupled to an SEM Scanning Electron Microscope, the elements present in the sample were determined; With the ICP-MS (Mass Spectrometry with Inductive Copled Plasma) team 40 measurements were made controlling the variables of adsorbent dose, pH, agitation time and concentration. It was possible to determine the presence of iron (Fe) with the help of an x-ray detector coupled to an SEM (Scanning Electron Microscope), the presence of iron is due to iron oxides such as: hemetite Fe2O3, goethite αFe3+O(OH) found covering the sand. Different variables were controlled to obtain a higher adsorption efficiency, the best solid dose was 1 g, the most significant pH was 7.33, the agitation time where there was a greater adsorption was 90 minutes and the concentration in which there was more adsorption was 30 mg.L-1. The adsorption of arsenic from aqueous media using sand coated with natural iron oxides is effective, proving that it has the capacity to remove 1 mg.g-1 of this metalloid, which is very polluting. It is recommended to use this type of soil that has the characteristic of adsorbing arsenic in the aqueous medium.