Characterization and Surface Properties of Bentonites in the Separation Process of Iron(III)

Abstract

Bentonite is an aluminum phyllosilicate, a clay consisting mainly of nanocrystalin particles of montmorillonite adsorbent. In this study, the physiochemical analyses of cation exchange capacity (CEC) measurements, methylene blue index (MBI), and characterization of bentonites for separation applications are examined. Some characterizations of bentonite particles such as surface properties were examined by scanning electron microscopy (SEM), x-ray diffraction (XRD), x-ray fluorescence (XRF), and Barret-Johner-Halenda (BJH) pore size distribution measurements. The adsorption of Fe(III) from a 0.01 N solution using bentonites has also been studied. The result showed that the amount of clay minerals (motmorillonite) is very high in sample A2 (from deposits of Toroud, Semnan Province of Iran). Results also show the MBI and CEC along with montmorillonite content were effective parameters on Fe(III) separation. Iron separation with removal efficiency of 52% for sample A1 (from deposits of Toroud, Semnan Province of Iran) is due to the difference in surface active doners (like O), silica entities with more homogeneous surface negative charge, interaction forces, and CEC.