Desenvolvimento de bioadsorventes a partir da casca da munguba para adsorção de metais.

Abstract

Produced Water is an effluent from the oil industry that contains heavy metals and has toxic and carcinogenic character. Thus, it is necessary to properly treat this effluent in order to remove the pollutants that are so harmful to the environment and human health. The adsorption is a of low cost, easy installation and operation method of treatment of produced water, however the use of activated carbon as an adsorbent increase the operation costs. An economically viable alternative is the use of bioadsorbers, natural materials with low added value. Thus, the present work sought to value the residue from the skin of the munguba fruit through its application as a potential bio-adsorbent for the treatment of produced water, evaluating the removal of heavy metals such as copper, lead and chromium by the finite bath adsorption method. The bio-absorbent used was the peel of the fruit of Pachira aquatica Aubl, munguba. The material was carbonized to obtain charcoal, and then it was characterized (immediate analysis, SEM, FT-IR and TGA). Subsequently, adsorption tests were carried out to obtain the metal removal efficiency, as well as the adsorption isotherms. From the characterization of the bioadsorber it was possible to observe that the material has a thermogram with characteristic events of lignocellulosic biomass, as well as a considerable amount of inorganic matter; it has FT-IR bands that represent organic groups present in lignin, cellulose and hemicellulose; the micrograph showed that its surface contains pores with different diameters. These characteristics are favorable for the adsorption process, indicating that the use of this material is viable for such a process. Viability confirmation was carried out through adsorption tests that showed that the metals were completely adsorbed with 10 g / L (0.5 g in 50 mL of solution) of bioadsorber in solution. From the linearized graphs of the Lagmuir and Freundlich models, it was possible to conclude that the Langmuir model was better adjusted to the experimental data of all metals, presenting higher R² values in all cases. The order of maximum removal capacity was lead, copper and chromium respectively. Finally, it is concluded that the bio-adsorbent produced from the bark of Pachira aquatica Aubl. has excellent performance for removing the studied metals, with satisfactory results.