ARGILITO PROVENIENTE DA REGIÃO DE PRUDENTÓPOLIS: MATERIAL ALTERNATIVO PARA REMOÇÃO DE AZUL DE METILENO POR ADSORÇÃO

Abstract

In this study, an argillite found in Prudentopolis/PR was characterized and tested as an adsorbent for the removal of a cationic dye, methylene blue (MB). The clay samples were characterized by scanning electron microscopy (SEM) with X-ray dispersive energy spectroscopy (EDX), FT-IR spectroscopy, zeta potential measurements, X-ray diffraction (XRD), and total surface area. Investigations were made to assess how the adsorption of MB was affected by factors such as contact time, initial MB concentration, initial adsorbent concentration, pH and temperature, using the batch adsorption technique. The argillite was identified as a smectite clay mineral, with a negative surface charge. Of the two models used, the Langmuir isotherm gave a better account of the equilibrium data than the Freundlich one, with the maximum amount adsorbed on equilibrium being qe = 95.0 mg g-1. The kinetics could be successfully replicated by a pseudo-second order model with an activation energy of 9.707 kJ mol−1, while the thermodynamic parameters indicated an endothermic (adsH = 6.979 kJ mol−1), spontaneous (adsG = -28.9 to -33.8 kJ mol−1) adsorption process.