Removal of Neutral Red from aqueous solution by using modified hectorite

The object of this work was to study the modified hectorite as effective adsorbent for Neutral Red (NR) from aqueous solution. The adsorbent capacity of modified hectorite was discussed. The effects of surfactant content, adsorbent content, pH and adsorption temperature on the sorption of NR on modified hectorite were studied. Experimental results showed that the equilibrium adsorption data fitted well with Langmuir isotherm and the adsorption capacity was 393.70 mg/g for the modified cetylpyridinium bromide hectorite (CPB-Hect). Kinetic studies showed that the dynamical data fitted well with the pseudo-second-order kinetic model. For thermodynamic studies, parameters such as the Gibbs free energy (Delta G degrees), the enthalpy (Delta H degrees) and the entropy (Delta S degrees) indicated that the adsorption process was spontaneous and endothermic in nature. (C) 2010 Elsevier B.V. All rights reserved.