Removal of hexavalent chromium from water by adsorption onto surfactant modified montmorillonite

The utilization of organoclays as adsorbents in the remediation of polluted water has been the subject of many recent research studies. In the present work, the adsorption of hexavalent chromium onto montmorillonite modified by the cationic surfactant cetylpyridinium bromide (CPB) was studied by aiming at water pollution remediation. The electrophoretic mobility measurements of the organo-montmorillonite showed a zeta potential reversion from negative to positive in the whole acidic pH range and up to pH 8.5. In some cases the adsorption of chromate ions onto the organo-montmorillonite was higher than 98% and was well described by the Langmuir adsorption isotherm. The utilization of montmorillonite modified by CPB showed to be an attractive solution to the remediation of water contaminated with chromate ions. (C) 2009 Elsevier Ltd. All rights reserved.