Dynamic aspects of coagulation and flocculation

The destabilization of colloidal suspensions by salt (i.e., coagulation) or by polymer flocculants (i.e., flocculation) is a phenomenon of scientific interest as well as industrial importance. The most characteristic feature is that the system undergoes an irreversible process controlled by hydrodynamic and physicochemical conditions. In this article, we pay attention mainly to the dispersion of a model colloid composed of uniform spheres undergoing rapid aggregation. The term “rapid” means that every collision leads to the formation of a floc. With this system, theoretical predictions on the kinetics of coagulation can be compared with experimental data, by which a standardized system can be established. This was ultimately useful for analyzing the kinetics of polymer flocculation.