Avaliação de bioadsorventes obtidos da torta de mamona para remoção de íons metálicos em solução aquosa utilizando coluna de adsorção em leito fixo

Abstract

The environmental contamination increase is a condition faced by the society nowadays. The contamination of the soil, water and other environments by heavy metals, has encouraged researchers to develop effective and low-cost technologies aiming the removal of these pollutes as, many times, standard treatment technologies are not capable of doing it efficiently. In this context, the bio-adsorption is showing itself as a promising option. The proposed research will make possible a more technically detailed study of the castor bean pie in the form of activated carbon, immobilized in chitosan as bio-adsorbent in the process of the copper ions removal in aqueous solutions, and of their features regards to the capacity of adsorption. Trials of adsorption in batch and in fixed bed columns were executed to evaluate the performance of the bio-adsorbents on the copper ions adsorption. According to the kinetic equilibrium data, we can see that for the copper ion, the maximum percentages removed were of 96.67% for the chitosan sphere, 95.11% for the spheres of activated carbon of the castor bean immobilized in chitosan, and 98.94% for the TM 500-90 carbon. The experimental models in chitosan of Langmuir and Freundlich were applied to the experimental data of adsorption equilibrium. The mathematical model of Langmuir was the one that better adapted to the equilibrium data for the TM 500-90 carbon, and the Freudlich model to the spheres of activated carbon of the castor bean pie immobilized in chitosan. Considering the experiments in continuous system, an experimental planning was defined of 23+ 3 central points, resulting in a variable flow of the bed feeding as the most significant, having a C/C0 of 0,97. The experimental design technique was used to evaluate the effects of variables concentration of aqueous solution synthetic of Cu2+ at the entrance of the bed height and flow ratio on the amount adsorbed by bioadsorbent. The most significant factor was the effect of the concentration of the metal followed bed height for the adsorbed amount response variable.