The use of dielectric spectroscopy in the investigation of the effect of polymer choice on the flocculation of polystyrene particles

Udgivelsesdato: MAR 1The flocculation of colloidal suspensions using synthetic polymeric flocculants is an important operationin separation processes. Optimizing flocculant use requires insight into the underlying mechanismsgoverning flocculation. As most existing methods for the online characterization of flocculation processescan only be used on dilute suspensions, new methods applicable at high solid content levels areof interest. This study used dielectric spectroscopy to investigate the mechanisms involved in theflocculation of polystyrene particles with three different cationic polymers. We observed that therelaxation time of the dielectric dispersion increased as particle flocculation was initiated. Reduction ofparticle charge due to polymer addition was found to reduce the magnitude of the dielectric dispersion,whereas the formation of aggregates increased it. This resulted in decreasing magnitude when chargereduction was the primary cause of flocculation, whereas the magnitude increased when the particleswere flocculated by bridging.