Determinación de la capacidad adsorbente del biocarbón obtenido de residuos vegetales combinados con nanopartículas de titanio para la remoción de mercurio de soluciones acuosas

Abstract

The objective of this work was to determine the adsorptive capacity of biochar from tocte and avocado residues combined with titanium nanoparticles to remove mercury from aqueous solutions. The first phase began with obtaining biochar from both avocado and tocte waste and then grinding and sieving it (63um mesh). The biochar obtained was incorporated into the process of synthesizing titanium nanoparticles, which were made from TiCl3, ethanol and water, and tests were carried out on porosity, scanning electron microscopy (SEM) and permanence of the nanoparticles in the biochar using infrared spectroscopy (FTIR). In the second phase, the optimum removal pH was determined by adjusting solutions of 10000 ug/L of Hg at pH 3, 5 and 7. After that, the experimental design in which adsorption tests were carried out at different concentrations (10000, 20000, 30000 and 50000 ug/L of Hg) and contact times (30, 60, 90, 120 and 150 minutes), resulting in the statistical analysis of completely randomized blocks, the best treatment was obtained, thus determining the kinetics and the necessary removal time. Finally, it was determined that the impregnated biochar presents titanium nanoparticles of 56.2 nm, in addition to FTIR stretching vibration signals that indicate the presence of carboxyl, aliphatic and aromatic groups, as well as the anatase phase. Also the adsorbents obtained from both avocado and tocte residues, presented porosities of 56% and 61%, the optimum pH of treatment was 7, the removal percentages were 99.72% at 30000 ug/L in avocado and 99.73% at 10000 ug/L for tocte, where the second order pseudokinetics was adapted to the data obtained and the removal times were found to be between 119.4253 and 127.1917 minutes.