Adsorção de fenol e benzeno em montmorilonita modificada com brometo de hexadeciltrimetilamônio

Abstract

This study evaluates the intercalation of the smectite dioctahedric state of Acre, Brazil, with the quaternary ammonium salt bromide, hexadecyltrimethylammonium (HDTMA) at concentrations ranging from 1 to 5 times the value of the original clay CEC and its application in the adsorption of phenol and benzene in the liquid phase. The materials were characterized by microanalysis X-ray diffraction, scanning electron microscopy /energy dispersive spectroscopy and infrared spectroscopy. The adsorption processes were carried out in simple systems and measurements of the concentrations of phenol and benzene were performed by spectrophotometry in the ultraviolet region. The results indicated that the intercalation of smectite with HDTMA provided approximately 78.8 expansion (range d001: 1.47 nm to 1.91 nm) and sharp decrease of the interlayer positions of elements such as Na, Ca, Mg and K, together by delamination/exfoliation of the clay original. In adsorption processes of phenol and benzene at HDTMA-arg 5 the following results were obtained: qmax = 4.44 and 35.8 mg.g-1; KL= 0.076 and 0.115 L.g-1; ΔGº = -16.85 and -18.38 kJ.mol-1, respectively. These data indicated that the adsorption of benzene and phenol in liquid phase in the organophilic HDTMA-arg 5 were favorable, spontaneous and physical interactions.