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

Abstract Silica–alumina particles prepared by the sol–gel method were used to adsorb metal ions in aqueous and alcoholic solutions. The flocculation kinetics of particles with a Si:Al molar composition 1:1 were studied in the presence of several metal ions by monitoring the particle growth with time using dynamic light scattering (DLS). Flocculation experiments were carried out following the two different routes: (a) adding small amounts of metal ions until the critical flocculation concentration was reached; (b) injecting the critical flocculation concentration all in one shot. The flocculated samples were characterized by atomic absorption spectroscopy (AA).