Aerogeles de Nanocelulosa Bacteriana: Una Alternativa Ambiental para la Remoción de Metales Pesados en Matrices Acuosas

Abstract

Water sources are currently facing significant challenges due to heavy metal contamination, which impacts both public health and resource availability. These harmful substances are toxic and disrupt the normal functioning of living organisms, thereby leading to health issues. The effective removal of these contaminants is a top priority, although traditional methods often have limitations and unwanted effects. To address this, research has turned toward more efficient and sustainable approaches such as employing aerogels as adsorbents. These aerogels feature functional groups, a large surface area, and porosity, which aid in capturing metal ions. An aerogel was developed using TEMPO-oxidized bacterial nanocellulose with a 0.5% oxidation degree, combined with hydrothermally synthesized PEI-functionalized carbon quantum dots. This environmentally friendly material was created to remove heavy metals from aqueous solutions. Various techniques, including UV-Vis, fluorescence, IR, SEM, TEM, and XPS, were used to analyze the optical properties, composition, size, morphology, surface composition, and stability. These examinations confirmed the dispersion of the amino-functionalized quantum dots on the surface of the aerogel. The metal removal tests demonstrated the efficiency of the aerogel in eliminating 40% of mercury and 32% of lead from the solution. Notably, the pseudo-second-order kinetic model and Langmuir isotherm prevailed, suggesting a chemisorption process that formed a uniform monolayer on the adsorbent surface. This sheds light on the nature of the adsorption mechanism, with promising implications for efficient heavy-metal removal.