Flocculation process of alumino-silicate particles using different metal ions in aqueous and alcoholic solutions

Silica-alumina particles prepared by the sol-gel method were used to adsorb metal ions in aqueous and alcoholic solutions. The flocculation kinetics o f particles with a Si:IU molar composition 1:1 were studied in the presence of several metal ions by monitoring the particle growth with time using dy namic light scattering (DLS). Flocculation experiments were carried out fol lowing the two different routes: (a) adding small amounts of metal ions unt il the critical flocculation concentration was reached; (b) injecting the c ritical flocculation concentration all in one shot. The floculated samples were characterized by atomic absorption spectroscopy(AA). (C) 2000 Elsevier science B.V. All rights reserved.