Remoção de metais pesados utilizando carvão de osso

Abstract

The present work aimed to contribute with the study of the mechanism of removal of ions Pb2+, Mn2+ and Cr3+ in batch process using bone char, as well as the study of removal of ions Mn2+ and Cr3+ in a fixed bed column, with the objective of seeking alternatives to the problem of pollution caused by the discharge of wastewater containing these ions. Initially, a pre-treatment of bone char was realized, followed by characterization, in which it was determined that the bone char has mesoporos and the N2 isotherm obtained is of type IV on the hysteresis of the type H4. It was then carried out a study of the removal mechanism of ions Pb2+, Mn2+ and Cr3+ using bone char in batch process, applying the modeling of kinetic and equilibrium data, being that the model of pseudo-second order was best represented the behavior kinetic systems, and the Freundlich isotherm model best represented the equilibrium data for single-component systems and Langmuir-Freundlich model best represented the equilibrium data for two-component systems. It was realized then a thermodynamic analysis for the single-component systems data obtained in batch process, which indicates the endothermic nature of the process for the three components. Dynamic data were also obtained in fixed bed column and within the range investigated, it can be stated that the flow rate of 20 mL.min-1 for tests with chromium, the flow rate of 5 mL.min-1 for tests with manganese and the average particle diameter of 0.180 mm minimized the diffusional resistance in dynamic sorption of bone char. The model presented by Silva (2001) was applied to the breakthrough curves obtained using the Langmuir isotherm parameters obtained in batch process.