Biorremediación de suelos contaminados con metales pesados en una zona minera mediante el uso de Sporosarcina pasteurii

Abstract

Abstract: Mining is one of the main mineral extraction activities in Ecuador; however, due to poor practices, it generates environmental pollution on both small and large scales. Despite this, the employment and income it produces are a fundamental part of the country's economy. This study aims to remediate mining soil contaminated with heavy metals through the application of the bacterium Sporosarcina Pasteurii. Samples were obtained from an old mine tailings site in the Ponce Enríquez Canton of Azuay Province. The physical and chemical parameters of the soil were analyzed. The applied treatment allowed for the microbial precipitation of carbonates through urea hydrolysis, achieving the immobilization of heavy metals. Three samples were evaluated: contaminated soil (BEFORE), remediated soil (A), and remediated soil (B). In treatment (A), a single dose of bacterial solution was applied, and in treatment (B), a double dose was applied. In both cases, nutrient solution (CaCl2) was added at 24 hours and 5 days, respectively. The results showed metal immobilization percentages in (A) 78.8%, 56.7%, 91.3%, 48.3%, 44.9%, 58.4%, of 51.2%, 57.6%, 51.8%, 50.8%, 53.5%, 50.7%, and 51.2%, and in (B) of and 78.8% for Cu, Ni, Zn, Cr, Pb, Fe, and Cd, respectively. Additionally, the presence of metals was detected in the leachate, indicating a slight entrainment of these elements.