ADSORÇÃO DE AZUL DE METILENO UTILIZANDO CARVÃO ATIVADO PREPARADO A PARTIR DA CASCA DO TAMBORIL (Enterolobium contortisiliquum)

Abstract

Contamination of natural resources by dyes present in industrial effluents causes serious impacts to the environment. Research on efficient methods to remove these contaminants has intensified in recent years. A promising method is adsorption, as it uses effective and low-cost adsorbents, such as biomass. In this study, the adsorptive capacity of carbon chemically activated with phosphoric acid (H3PO4) obtained from monkfish (Enterolobium contortisiliquum) shells was investigated for the removal of methylene blue (MB) dye in aqueous medium. UV-Visible was used to quantify the dye removed from the experimental batch method. Adsorption tests at different temperatures suggest that the Langmuir isotherm model (R2 = 0.9967) and the pseudo-second order kinetic model better fit the experimental data. The negative values of ∆Hads and ∆Gads express that the adsorption dynamics is exothermic and spontaneous. The positive value of ∆Sads suggests an increase in disorder at the solid-solution interface during the process. Under these conditions, TCA (monkfish activated charcoal) presented a qe of 525.15 mg g-1, reaching a removal percentage of 82.67%. The treatment carried out to obtain activated carbon allowed the SEM, BET and FT-IR analyses to reveal a porous surface with the presence of micro and mesopores and acid groups on the TCA surface.

Keywords

• adsorption
• activated charcoal
• biosorbent
• methylene blue
• Enterolobium contortisiliquum.